KR20060126128A - Shift register - Google Patents

Abstract

The present invention relates to a shift register that can prevent distortion of scan pulses supplied to a gate line of a liquid crystal panel, and increases and outputs a pulse width of each scan pulse so that the scan pulses overlap each other for a predetermined time. The present invention provides a shift register that can prevent distortion of the scan pulse by increasing the effective charge time in which the scan pulse continues to the target voltage.

Description

A shift register

1 is a view showing a conventional shift register

2 is a diagram illustrating an ideal waveform of a scan pulse and a waveform of a distorted scan pulse;

3 illustrates a shift register according to a first embodiment of the present invention.

4 is a timing diagram of first to fourth clock pulses and first to fourth scan pulses.

5 is a view for comparing the conventional scan pulse and the scan pulse according to the present invention.

6 is a view showing a simulation waveform for a conventional scan pulse and the scan pulse of the present invention.

FIG. 7 is a circuit diagram illustrating the third stage of FIG. 3.

8A and 8B show first to third stages having the circuit configuration of FIG.

FIG. 9 is another circuit diagram of the third stage of FIG.

10A and 10B show first to third stages having the circuit configuration of FIG.

11 illustrates a shift register according to a second embodiment of the present invention.

12 is a circuit diagram illustrating the third stage of FIG. 11.

FIG. 13 is a view illustrating first to third stages having the circuit configuration of FIG. 12. FIG.

14 is another circuit diagram of the third stage of FIG.

15A and 15B show first to third stages having the circuit configuration of FIG.

16 illustrates a shift register according to a third embodiment of the present invention.

17 is a circuit diagram illustrating the third stage of FIG. 16.

18A and 18B show first to third stages having the circuit configuration of FIG.

* Explanation of symbols on the main parts of the drawings

BST1 to BSTn: first to nth stages

BSTn + 1: first dummy stage

BSTn + 2: second dummy stage VDD1: first voltage source

VDD2: Second voltage source VSS: Third voltage source

SP: Start pulse

Vout1 to Voutn + 2: first to n + 2 scan pulses

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift register of a liquid crystal display device. In particular, a shift register capable of preventing distortion of the scan pulse by outputting by increasing the pulse width of each scan pulse so that the scan pulses overlap each other for a predetermined time. It is about.

Conventional liquid crystal display devices display an image by adjusting the light transmittance of the liquid crystal using an electric field. To this end, the liquid crystal display includes a liquid crystal panel in which pixel regions are arranged in a matrix, and a driving circuit for driving the liquid crystal panel.

In the liquid crystal panel, a plurality of gate lines and a plurality of data lines are arranged to cross each other, and a pixel region is positioned in an area defined by vertical crossings of the gate lines and the data lines. Pixel electrodes and a common electrode for applying an electric field to each of the pixel regions are formed in the liquid crystal panel.

Each of the pixel electrodes is connected to the data line via a source electrode and a drain electrode of a thin film transistor (TFT) which is a switching element. The thin film transistor is turned on by a scan pulse applied to the gate electrode via the gate line, so that the data signal of the data line is charged to the pixel voltage.

The driving circuit may include a gate driver for driving the gate lines, a data driver for driving the data lines, a timing controller for supplying a control signal for controlling the gate driver and the data driver, and a liquid crystal display device. It is provided with a power supply for supplying a variety of driving voltages used in.

The timing controller controls driving timing of the gate driver and the data driver and supplies a pixel data signal to the data driver. The power supply unit boosts or decompresses an input power to generate driving voltages such as a common voltage VCOM, a gate high voltage signal VGH, and a gate low voltage signal VGL required by the liquid crystal display. The gate driver sequentially supplies scan pulses to the gate lines to sequentially drive the liquid crystal cells on the liquid crystal panel by one line. The data driver supplies a pixel voltage signal to each of the data lines whenever a scan pulse is supplied to any one of the gate lines. Accordingly, the liquid crystal display displays an image by adjusting light transmittance by an electric field applied between the pixel electrode and the common electrode according to the pixel voltage signal for each liquid crystal cell.

Here, the gate driver includes a shift register to sequentially output the scan pulses as described above. This will be described in more detail with reference to the accompanying drawings.

1 is a diagram illustrating a conventional shift register.

As shown in FIG. 1, the conventional shift register includes n stages AST1 to ASTn and one dummy stage ASTn + 1 connected dependently to each other. Here, each of the stages AST1 to ASTn + 1 outputs one scan pulse Vout1 to Voutn + 1, and in this case, the scan pulse Vout1 sequentially from the first stage AST1 to the dummy stage ASTn + 1. To Voutn + 1). In this case, scan pulses Vout1 to Voutn output from the stages AST1 to ASTn except for the dummy stage ASTn + 1 are sequentially supplied to gate lines of the liquid crystal panel (not shown). The gate lines are sequentially scanned.

The entire stages AST1 to ASTn + 1 of the shift register configured as described above are configured with the first voltage source VDD and the second voltage source VSS, and the first to fourth clock pulses CLK1 to CLK4 having sequential phase differences with each other. Two clock pulses are received. Here, the first voltage source VDD means a positive voltage source, and the second voltage source VSS means a negative voltage source.

Meanwhile, the first stage AST1 positioned at the uppermost side of the stages AST1 to ASTn + 1 may include a start pulse (in addition to the first voltage source VDD, the second voltage source VSS, and the two clock pulses). SP).

The operation of the conventional shift register configured as described above will be described in detail as follows.

First, when a start pulse SP from a timing controller (not shown) is applied to the first stage AST1, the first stage AST1 is enabled in response to the start pulse SP.

Subsequently, the enabled first stage AST1 receives the first and second clock pulses CLK1 to CLK2 from the timing controller, and outputs the first scan pulse Vout1, and the first gate line and the first gate line. It is supplied together to the 2 stage AST2. Then, the second stage AST2 is enabled in response to the first scan pulse Vout1.

Subsequently, the enabled second stage AST2 receives the second and third clock pulses CLK2 and CLK3 from the timing controller and outputs a second scan pulse Vout2, and the second gate line, The third stage AST3 and the first stage AST1 are supplied together. Then, the third stage AST3 is enabled in response to the second scan pulse Vout2, and the first stage AST1 is disabled in response to the second scan pulse Vout2. A second voltage source VSS is supplied to the first gate line.

Subsequently, the enabled third stage AST3 receives the third and fourth clock pulses CLK3 and CLK4 from the timing controller, and outputs a third scan pulse Vout3, and the third gate line, The fourth stage AST4 and the second stage AST2 are supplied together. Then, the fourth stage AST4 is enabled in response to the third scan pulse Vout3, and the second stage AST2 is disabled in response to the third scan pulse Vout3. A second voltage source VSS is supplied to the second gate line.

In this manner, the fourth to nth scan pulses Voutn are sequentially output to the remaining fourth to nth stages AST4 to ASTn and sequentially applied to the fourth to nth gate lines. As a result, the first to nth gate lines are sequentially scanned by the sequentially output first to nth scan pulses Vout1 to Voutn.

Meanwhile, the dummy stage ASTn + 1 is enabled in response to the nth scan pulse Voutn from the nth stage ASTn, and then receives two clock pulses from the timing controller. One scan pulse Voutn + 1 is supplied to the nth stage ASTn so that the nth stage ASTn is disabled to provide the second voltage source VSS to the nth gate line. In other words, the dummy stage ASTn + 1 merely provides the n + 1 scan pulse Voutn + 1 so that the nth stage ASTn can output the second voltage source VSS. The n + 1th scan pulse Voutn + 1 is not supplied to the gate line. Therefore, the total number of stages including the dummy stage ASTn + 1 is always one more than the number of gate lines.

On the other hand, the conventional shift register configured as described above has the following problems.

2 illustrates an ideal waveform of a scan pulse and a waveform of a distorted scan pulse.

As the liquid crystal display becomes larger, the length of the gate line also becomes longer. As the length of the gate line increases, the resistance and capacitance components of the gate line also increase. Then, as shown in FIG. 2, the scan pulse 201 supplied to the gate line by the resistance and capacitance components may be distorted. FIG. 201 shows an ideal scan pulse 201 when it is assumed that there is no resistance and capacitance component in the gate line. On the other hand, when the scan pulse 201 is distorted by the resistance and capacitance components, the rise time TR of the scan pulse 201 is increased and the waveform thereof is distorted. FIG. 202 is a scan pulse 202 distorted by the resistance and capacitance components of the gate line. Since the distorted scan pulse 202 has a longer rise time TR than the ideal scan pulse 201, the effective charge time TS maintained at the target voltage VT is shortened. When the scan pulse 202 whose waveform is distorted in this way is applied to the gate electrode of the thin film transistor, the turn-on time of the thin film transistor is shortened, which causes the turned-on thin film transistor from the data line. The time for switching the data voltage is also shortened. As a result, the waveform of the data voltage applied to the pixel electrode via the drain / source terminal of the turned-on thin film transistor is also distorted, which causes a problem that the data voltage is not sufficiently charged in the pixel electrode.

The present invention has been made to solve the above problems, by increasing the pulse width of each scan pulse so that each scan pulse overlap each other for a certain time, and outputs, the effective charge time that each scan pulse is maintained at the target voltage The purpose of the present invention is to provide a shift register capable of preventing distortion of the scan pulse.

The shift register according to the present invention for achieving the above object, in response to the clock pulses from the timing controller, sequentially outputs a plurality of scan pulses so that a predetermined interval of their pulse width overlap each other, and these 10. A shift register comprising a plurality of stages for sequentially supplying gate lines of the plurality of stages, wherein each stage charges a first node to the scan pulse in response to a start pulse or a scan pulse from a previous stage. 1 switching element; A second switching element discharging a second node to a first voltage source in response to a scan pulse charged in the first node; A third switching device discharging a third node to a first voltage source in response to a scan pulse charged in the first node; A fourth switching element that is turned on or off in response to a second voltage source having a different polarity for each frame, and charges a second node with the second voltage source when turned on; A fifth switching element configured to discharge the first node to the first voltage source in response to the second voltage source charged in the second node; A sixth switching element which is turned on or off in response to the second voltage source and discharges the third node to the second voltage source when turned on; A seventh switching element having a different polarity for each frame and being turned on or off in response to a third voltage source having an inverted polarity with respect to the second voltage source, wherein the seventh switching element charges a third node with the third voltage source during turn-on; An eighth switching device discharging the first node to the first voltage source in response to the third voltage source charged in the third node; A ninth switching element that is turned on or off in response to the third voltage source and discharges a second node to the first voltage source when turned on; A tenth switching element for discharging the first node to the first voltage source in response to the scan pulse from the next stage; An eleventh switching device configured to output a scan pulse in response to the scan pulse charged in the first node, and supply the scan pulse to the gate line, the next stage, and the previous stage; A twelfth switching element configured to supply a first voltage source to the gate line in response to the second voltage source charged in the second node; And a thirteenth switching element for supplying the first voltage source to the gate line in response to the third voltage source charged in the third node.

In addition, the shift register according to the present invention for achieving the above object, in response to the clock pulses from the timing controller, sequentially outputs a plurality of scan pulses so that a predetermined section of their pulse width overlap each other, A shift register including a plurality of stages sequentially supplied to gate lines of a liquid crystal panel, wherein each stage charges a first node with the scan pulse in response to a start pulse or a scan pulse from a previous stage. A first switching device to make; A second switching element for discharging the second node to the first voltage source in response to the scan pulse charged in the first node; A third switching element for discharging the third node to the first voltage source in response to the scan pulse charged in the first node; A fourth switching element for discharging the second node to the first voltage source in response to the start pulse or the scan pulse from the previous stage; A fifth switching element for discharging the third node to the first voltage source in response to the start pulse or the scan pulse from the previous stage; A sixth switching element turned on or off in response to a second voltage source having a different polarity for each frame and outputting the second voltage source when turned on; A seventh switching device configured to charge a second node with a second voltage source in response to the second voltage source output from the sixth switching device; An eighth switching element for discharging the first node to the first voltage source in response to the second voltage source charged to the second node; A ninth switching element which turns off the seventh switching element by supplying a first voltage source to the gate terminal of the seventh switching element in response to the scan pulse charged in the first node; A tenth switching element for turning off the seventh switching element by supplying a first voltage source to the gate terminal of the seventh switching element in response to a start pulse or a scan pulse from a previous stage; An eleventh switching element having a different polarity for each frame and being turned on or off in response to a third voltage source having a polarity inverted to the second voltage source, and outputting the third voltage source when turned on; A twelfth switching device configured to charge a third node with the third voltage source in response to a third voltage source output from the eleventh switching device; A thirteenth switching element discharging the first node to the first voltage source in response to the third voltage source charged to the third node; A fourteenth switching element turning off the twelfth switching element by supplying a first voltage source to the gate terminal of the twelfth switching element in response to the scan pulse charged in the first node; A fifteenth switching element that turns off the twelfth switching element by supplying a first voltage source to the gate terminal of the twelfth switching element in response to a start pulse or a scan pulse from a previous stage; A sixteenth switching element for discharging the first node to the first voltage source in response to the scan pulse from the next stage; A seventeenth switching element outputting the scan pulse in response to the scan pulse charged in the first node and supplying the scan pulse to the gate line, the next stage, and the previous stage; An eighteenth switching element configured to supply a first voltage source to the gate line in response to the second voltage source charged in the second node; And a nineteenth switching element configured to supply the first voltage source to the gate line in response to the third voltage source charged in the third node.

In addition, the shift register according to the present invention for achieving the above object, in response to the clock pulses from the timing controller, sequentially outputs a plurality of scan pulses so that a predetermined section of their pulse width overlap each other, A shift register including a plurality of stages sequentially supplied to gate lines of a liquid crystal panel, wherein each stage charges a first node with a first voltage source in response to a start pulse or a scan pulse from a previous stage. A first switching device to make; A second switching element for discharging a second node to a second voltage source in response to a start pulse or a scan pulse from a previous stage; A third switching element for discharging the third node to the second voltage source in response to the start pulse or the scan pulse from the previous stage; A fourth switching element which is turned on or turned off in response to a third voltage source having a different polarity for each frame, and charges the second node with a third voltage source at turn-on; A fifth switching element turned on or off in response to the third voltage source and discharging the third node to the second voltage source at turn-on; A sixth switching element that is turned on or off in response to a fourth voltage source and charges a third node with the fourth voltage source when turned on; A seventh switching element turned on or off in response to the fourth voltage source and discharging the second node to the second voltage source; An eighth switching element for discharging the second node to the second voltage source in response to the first voltage source charged to the first node; A ninth switching element configured to discharge the third node to the second voltage source in response to the first voltage source charged in the first node; A tenth switching element configured to discharge the first node to the second voltage source in response to the third voltage source charged in the second node; An eleventh switching element configured to discharge the first node to the second voltage source in response to the fourth voltage source charged to the third node; A twelfth switching element for discharging the first node to the second voltage source in response to the scan pulse from the next stage; A thirteenth switching element configured to output a scan pulse in response to the first voltage source charged in the first node, and supply the scan pulse to the gate line, the next stage stage, and the previous stage stage; A fourteenth switching element for supplying a second voltage source to the gate line in response to the third voltage source charged in the second node; And a fifteenth switching element for supplying the second voltage source to the gate line in response to the fourth voltage source charged in the third node.

In addition, the shift register according to the present invention for achieving the above object, in response to the clock pulses from the timing controller, sequentially outputs a plurality of scan pulses so that a predetermined section of their pulse width overlap each other, A shift register including a plurality of stages sequentially supplied to gate lines of a liquid crystal panel, wherein each stage charges a first node with a first voltage source in response to a start pulse or a scan pulse from a previous stage. A first switching device to make; A second switching element for discharging the second node to the second voltage source in response to the first voltage source charged to the first node; A third switching element configured to discharge the third node to the second voltage source in response to the first voltage source charged in the first node; A fourth switching element turned on or off in response to a third voltage source having a different polarity for each frame, and outputting the third voltage source at turn-on; A fifth switching device configured to charge a second node with a third voltage source in response to the third voltage source output from the fourth switching device; A sixth switching element discharging the first node to the second voltage source in response to the third voltage source charged to the second node; A seventh switching element configured to discharge the third node to the second voltage source in response to the third voltage source charged in the second node; An eighth switching device which turns off the fifth switching device by supplying a second voltage source to the gate terminal of the fifth switching device in response to the first voltage source charged in the first node; A ninth switching element for turning off the fifth switching element by supplying a second voltage source to the gate terminal of the fifth switching element in response to a start pulse or a scan pulse from a previous stage; A tenth switching element for turning off the fifth switching element by supplying a second voltage source to the gate terminal of the fifth switching element in response to a start pulse or a scan pulse from a previous stage; An eleventh switching element having a different polarity for each frame and being turned on or off in response to a fourth voltage source having a polarity inverted to the third voltage source, and outputting the fourth voltage source when turned on; A twelfth switching device configured to charge a third node with the fourth voltage source in response to a fourth voltage source output from the eleventh switching device; A thirteenth switching element discharging the first node to the second voltage source in response to the fourth voltage source charged to the third node; A fourteenth switching element configured to discharge the second node to the second voltage source in response to the fourth voltage source charged to the third node; A fifteenth switching element that turns off the twelfth switching element by supplying a second voltage source to the gate terminal of the twelfth switching element in response to the first voltage source charged in the first node; A sixteenth switching element that turns off the twelfth switching element by supplying a second voltage source to the gate terminal of the twelfth switching element in response to a start pulse or a scan pulse from a previous stage; A seventeenth switching element that turns off the twelfth switching element by supplying a second voltage source to the gate terminal of the twelfth switching element in response to a start pulse or a scan pulse from a previous stage; An eighteenth switching element for discharging the second node to the second voltage source in response to the start pulse or the scan pulse from the previous stage; A nineteenth switching element for discharging the third node to the second voltage source in response to the start pulse or the scan pulse from the previous stage; A twentieth switching element for discharging the first node to the second voltage source in response to the scan pulse from the next stage; A twenty-first switching element configured to output a scan pulse in response to the first voltage source charged in the first node, and supply the scan pulse to the gate line, the next stage, and the previous stage; A twenty-second switching element configured to supply a second voltage source to the gate line in response to a third voltage source charged in the second node; And a twenty-third switching element for supplying the second voltage source to the gate line in response to the fourth voltage source charged in the third node.

In addition, the shift register according to the present invention for achieving the above object, in response to the clock pulses from the timing controller, sequentially outputs a plurality of scan pulses so that a predetermined section of their pulse width overlap each other, A shift register including a plurality of stages sequentially supplied to gate lines of a liquid crystal panel, wherein each stage charges a first node with a first voltage source in response to a start pulse or a scan pulse from a previous stage. A first switching device to make; A second switching element for discharging the second node to the second voltage source in response to the first voltage source charged to the first node; A third switching element configured to discharge the third node to the second voltage source in response to the first voltage source charged in the first node; A fourth switching element turned on or off in response to a third voltage source having a different polarity for each frame, and outputting the third voltage source at turn-on; A fifth switching device configured to charge a second node with a third voltage source in response to the third voltage source output from the fourth switching device; A sixth switching element discharging the first node to the second voltage source in response to the third voltage source charged to the second node; A seventh switching element for discharging the third node to the second voltage source in response to the third voltage source charged to the second node; An eighth switching device which turns off the fifth switching device by supplying a second voltage source to the gate terminal of the fifth switching device in response to the first voltage source charged in the first node; A ninth switching element for turning off the fifth switching element by supplying a second voltage source to the gate terminal of the fifth switching element in response to a start pulse or a scan pulse from a previous stage; A tenth switching element for turning off the fifth switching element by supplying a second voltage source to the gate terminal of the fifth switching element in response to a start pulse or a scan pulse from a previous stage; An eleventh switching element having a different polarity for each frame and being turned on or off in response to a fourth voltage source having a polarity inverted to the third voltage source, and outputting the fourth voltage source when turned on; A twelfth switching device configured to charge a third node with the fourth voltage source in response to a fourth voltage source output from the eleventh switching device; A thirteenth switching element discharging the first node to the second voltage source in response to the fourth voltage source charged to the third node; A fourteenth switching element configured to discharge the second node to the second voltage source in response to the fourth voltage source charged to the third node; A fifteenth switching element that turns off the twelfth switching element by supplying a second voltage source to the gate terminal of the twelfth switching element in response to the first voltage source charged in the first node; A sixteenth switching element that turns off the twelfth switching element by supplying a second voltage source to the gate terminal of the twelfth switching element in response to a start pulse or a scan pulse from a previous stage; A seventeenth switching element that turns off the twelfth switching element by supplying a second voltage source to the gate terminal of the twelfth switching element in response to a start pulse or a scan pulse from a previous stage; An eighteenth switching element for discharging the second node to the second voltage source in response to the start pulse or the scan pulse from the previous stage; A nineteenth switching element for discharging the third node to the second voltage source in response to the start pulse or the scan pulse from the previous stage; A twentieth switching element that discharges the first node to a second voltage source in response to a scan pulse from the next stage; A twenty-first switching element configured to output a scan pulse in response to the first voltage source charged in the first node, and supply the scan pulse to the gate line, the next stage, and the previous stage; A twenty-second switching element configured to supply a second voltage source to the gate line in response to a third voltage source charged in the second node; A twenty-third switching element configured to supply a second voltage source to the gate line in response to the fourth voltage source charged in the third node; A twenty-fourth switching element configured to output a scan pulse in response to the first voltage source charged in the first node and to supply the scan pulse to the gate line, the next stage, and the previous stage; A twenty fifth switching element configured to supply a second voltage source to the gate line in response to a third voltage source charged in the second node; And a twenty-sixth switching element for supplying the second voltage source to the gate line in response to the fourth voltage source charged in the third node.

Hereinafter, a shift register according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a configuration diagram of a shift register according to a first embodiment of the present invention.

The shift register of the liquid crystal display according to the first exemplary embodiment of the present invention includes a plurality of scans in response to the clock pulses CLK1 to CLK4 and the start pulse SP from the timing controller, as shown in FIG. The pulses Vout1 to Voutn are sequentially output, and at this time, the pulse width of each of the scan pulses Vout1 to Voutn is increased so that the adjacent scan pulses Vout1 to Voutn overlap each other by a predetermined time. Output to the gate line.

Although not shown in the drawing, the liquid crystal panel includes a plurality of gate lines arranged in one direction and a plurality of data lines arranged to vertically cross the gate lines, and the data lines output data from a data driver. It is charged by voltage. In addition, a thin film transistor and a pixel electrode are formed in each pixel area defined by the gate line and the data line. Specifically, the thin film transistor is formed near the intersection of the gate line and the data line. The thin film transistor switches the data voltage charged in the data line to the pixel electrode in response to the scan pulses Vout1 to Voutn charged in each gate line, thereby displaying an image on the liquid crystal panel.

Meanwhile, as illustrated in FIG. 3, the shift register is composed of n stages connected to each other and first and second dummy stages BSTn + 1 and BSTn + 2. Here, all the stages BST1 to BSTn + 2 output one scan pulse Vout1 to Voutn + 2, and in this case, scan pulses are sequentially performed from the first stage BST1 to the second dummy stage BSTn + 2. (Vout1 to Voutn + 2) is output. In this case, the scan pulses Vout1 to Voutn output from the stages BST1 to BSTn except for the first and second dummy stages BSTn + 1 and BSTn + 2 are connected to the liquid crystal panel (not shown). The gate lines are sequentially supplied to sequentially scan the gate lines. Here, the shift register consisting of the stages BST1 to BSTn + 2 is preferably embedded on the liquid crystal panel.

On the other hand, the entire stages BST1 to BSTn + 2 of the shift registers configured as described above are the first to third voltage sources VDD1, VDD2 and VSS and the first to fourth clock pulses CLK1 to CLK4 circulating with sequential phase differences. One clock pulse is applied. Here, the first voltage source VDD1 and the second voltage source VDD2 represent AC voltages having alternating positive and negative voltages, respectively, and the first voltage source VDD1 and the second voltage source VDD2 each other. It has an inverted phase. The third voltage source VSS is a direct current voltage and shows negative polarity. Each of the first to fourth clock pulses CLK1 to CLK4 is repeatedly output with a predetermined period.

Here, the first stage BST1 located on the uppermost side of the stages BST1 to BSTn + 2 may include the first to third voltage sources VDD1, VDD2, and VSS and the first to fourth clock pulses. In addition to the two clock pulses (CLK1 to CLK4), the start pulse SP is supplied.

On the other hand, as described above, the first to fourth clock pulses CLK1 to CLK4 are delayed and outputted from each other. That is, the second clock pulse CLK2 is output after being phase-delayed than the first clock pulse CLK1, and the third clock pulse CLK3 is output by being phase-delayed than the second clock pulse CLK2. The fourth clock pulse CLK4 is output in phase delay than the third clock pulse CLK3 and the first clock pulse CLK1 is output in phase delay than the fourth clock pulse CLK4.

Meanwhile, the start pulse SP applied to the first stage BST1 among the stages BST1 to BSTn + 2 is output earlier than the clock pulses CLK1 to CLK4. In addition, the start pulse SP is output only once in one frame. That is, after the start pulse SP is first outputted every frame, the first to fourth clock pulses CLK1 to CLK4 are sequentially output. At this time, the first to fourth clock pulses CLK1 to CLK4 are sequentially output, and are also output while circulating. That is, after the first clock pulse CLK1 to the fourth clock pulse CLK4 are sequentially output, the first clock pulse CLK1 to the fourth clock pulse CLK4 are sequentially output. Therefore, the first clock pulse CLK1 is output in a period corresponding to the fourth clock pulse CLK4 and the second clock pulse CLK2. The fourth clock pulse CLK4 and the start pulse SP may be output in synchronization with each other. In this case, the fourth clock pulse CLK4 is first outputted among the first to fourth clock pulses CLK1 to CLK4.

Meanwhile, the shift register according to the present invention may use two or more clock pulses. That is, the shift register according to the present invention may use only the first and second clock pulses CLK1 and CLK2 among the first to fourth clock pulses CLK1 to CLK4, and the first to third clock pulses CLK1 to CLK4. You can also use only CLK3). In addition, the shift register according to the present invention may use four or more clock pulses sequentially output.

The operation of the shift register configured as described above will be described in detail as follows.

First, when the start pulse SP from the timing controller is input to the first stage BST1, the first stage BST1 is enabled in response to the start pulse SP. Subsequently, the enabled first stage BST1 receives the first clock pulse CLK1 from the timing controller and outputs a first scan pulse Vout1. The first stage BST1 receives the first gate line and the second stage BST2. To feed. Then, the second stage BST2 is enabled in response to the first scan pulse Vout1. Subsequently, the enabled second stage BST2 receives the second clock pulse CLK2 from the timing controller and outputs a second scan pulse Vout2. The second stage BST2 receives the second gate line and the third stage BST3. Supplies). Then, the third stage BST3 is enabled in response to the second scan pulse Vout2. Subsequently, the enabled third stage BST3 receives the third clock pulse CLK3 from the timing controller and outputs a third scan pulse Vout3, and the third gate line and the fourth stage BST4. And the first stage BST1 together. Then, the fourth stage BST4 is enabled in response to the third scan pulse Vout3, and the first stage BST1 supplies a third voltage source VSS to the first gate line. Subsequently, the enabled fourth stage BST4 receives the fourth clock pulse CLK4 from the timing controller and outputs a fourth scan pulse Vout4, and the fourth gate line, the fifth stage, and It supplies to the 2nd stage BST2. Then, the fifth stage is enabled in response to the fourth scan pulse Vout4, and the second stage BST2 supplies the third voltage source VSS to the second gate line. Subsequently, the enabled fifth stage receives the first clock pulse CLK1 from the timing controller and outputs a fifth scan pulse, and the fifth gate line, the sixth stage, and the third stage BST3. ) Together. Then, the sixth stage is enabled in response to the fifth scan pulse, and the third stage BST3 supplies a third voltage source VSS to the third gate line. In this manner, the sixth to nth scan pulses Voutn are sequentially output to the sixth to nth stages BSTn, and they are sequentially supplied to the sixth to nth gate lines, respectively. In this case, the adjacent scan pulses have a pulse width section overlapping by a predetermined time. Here, the first dummy stage BSTn + 1 serves to supply the n + 1th scan pulse Voutn + 1 to the n-1th stage BSTn-1 and the second dummy stage BSTn + 2. 300h serves to supply the n th +2 th scan pulse Voutn + 2 to the n th stage BSTn. That is, the n + 1 and n + 2 scan pulses Voutn + 1 and Voutn + 2 output from the first and second dummy stages BSTn + 1 and BSTn + 2 are not supplied to the gate line. Only the dummy outputs serve to output the third voltage source VSS by the n-th and n-th stages BSTn.

As described above, each stage BST1 to BSTn + 2 outputs scan pulses Vout1 to Voutn + 2, and supplies them sequentially to the corresponding gate lines, respectively, and at the next stage, as a start pulse SP. to provide. Each of the stages BST1 to BSTn + 2 supplies a third voltage source VSS to a corresponding gate line in response to a scan pulse output from a stage positioned next to the next stage. As described above, the reason why each stage receives the scan pulse output from the stage located in the next stage from the next stage, rather than the next stage will be described in detail. Prior to this, each of the scan pulses Vout1 to Voutn and the first to fourth clock pulses CLK1 to CLK4 will be described in more detail. Here, since all of the scan pulses Vout1 to Voutn have the same waveform, the first to fourth scan pulses Vout1 to Vout4 will be described as an example.

4 is a timing diagram of first to fourth clock pulses and first to fourth scan pulses.

First, as shown in FIG. 4, the pulse widths of the first to fourth scan pulses Vout1 to Vout4 may be divided into a preliminary charging section A and an effective charging section B, and each scan pulse Vout1 to V1. The preliminary charging section A of Vout4) partially overlaps with the effective charging section B of the previous scan pulse in time. Further, the effective charging section B of each scan pulse Vout1 to Vout4 partially overlaps the preliminary charging section A of the next scan pulse in time. Accordingly, each of the scan pulses Vout1 to Vout4 starts to be output in the effective charge section B of the previous scan pulse and reaches the target voltage VT in its effective charge section B. In other words, each scan pulse Vout1 to Vout4 gradually increases toward its target voltage VT in its preliminary charging section A, and then maintains the target voltage VT completely in its effective charging section B. do.

That is, the first scan pulse Vout1 starts to be output in one section of the start pulse SP corresponding to its preliminary charging section A, and in the effective charging section B thereof, the target voltage VT. Fully maintained. In addition, the second scan pulse Vout2 starts to be output in the effective charging section of the first scan pulse Vout1 corresponding to the preliminary charging section A of the second scan pulse Vout1, and completely targets the valid scan section V of the second scan pulse Vout2. It is maintained at the voltage VT. In addition, the third scan pulse Vout3 starts to be output in the effective charge section B of the second scan pulse Vout2 corresponding to the preliminary charge section A of its own, and thus, the valid charge section B thereof. Is completely maintained at the target voltage (VT). In addition, the fourth scan pulse Vout4 starts to be output in the effective charge section B of the third scan pulse Vout3 corresponding to its preliminary charge section A, and thus its effective charge section B. Is completely maintained at the target voltage (VT).

Accordingly, each of the scan pulses Vout1 to Vout4 has a pulse width substantially longer than the conventional scan pulses by the pulse width corresponding to the preliminary charging section A, and thus the scan pulses Vout1 to Vout4. There is an advantage that the turn-on time of the thin film transistor of the liquid crystal panel is applied.

The scan pulses Vout1 to Vout4 are output in synchronization with the first to fourth clock pulses CLK1 to CLK4 output from the timing controller, and thus the first to fourth clock pulses CLK1 to CLK4 are also output. The scan pulses Vout1 to Vout4 have overlapping sections.

Here, since the first to fourth clock pulses CLK1 to CLK4 continuously cycle with a phase difference, the first clock pulse CLK1 overlaps the fourth clock pulse CLK4. On the other hand, the fourth clock pulse CLK4 is synchronized with the start pulse SP.

The scan pulse of the present invention will be described in comparison with the conventional scan pulse as follows. Here, the first and second scan pulses Vout1 'and Vout2', and the first and second scan pulses Vout1 and Vout2 of the present invention will be described by way of example.

5 is a view illustrating a comparison between a conventional scan pulse and a scan pulse according to the present invention, and FIG. 6 is a view illustrating a simulation waveform of a conventional scan pulse and a scan pulse of the present invention.

When the waveforms of the first and second scan pulses Vout1 and Vout2 are distorted by the resistance and capacitance components of the gate line, the rise time TR of the conventional first and second scan pulses Vout1 and Vout2 is increased, and thus, Accordingly, the effective charging time TS at which the first and second scan pulses Vout1 and Vout2 are maintained at the target voltage VT is reduced. On the other hand, the data voltage Data is applied to the data line while periodically changing to positive and negative polarity, at which time the effective charge time TS of the scan pulse is maintained at the positive voltage (1H). ) Or shorter than the time (1H) maintained at the negative polarity, so that the data voltage (Data) is not normally applied to the pixel electrode.

However, the first scan pulse Vout1 of the present invention starts to be output from a point corresponding to one section of the start pulse SP (corresponding to the preliminary charging section A of the first scan pulse Vout1) and gradually starts to be output. The target voltage VT is increased to reach the target voltage VT, and then is maintained at the target voltage VT completely for the time corresponding to the effective charge section B thereof. That is, the rise time TR of the first scan pulse Vout1 is not included in the time corresponding to the effective charging section B of the first scan pulse Vout1, and the first scan pulse Vout1 does not include the rising time TR. Since it is included in the time corresponding to the preliminary charging section A, the time corresponding to the effective charging section B of the first scan pulse Vout1 is not reduced by the rising time TR. In addition, the second scan pulse Vout2 corresponds to the effective charging section B of the first scan pulse Vout1 (corresponding to the preliminary charging section A of the second scan pulse Vout2). It starts outputting and gradually reaches the target voltage VT, and then maintains the target voltage VT completely for a time corresponding to its effective charging section B. That is, the rising time TR of the second scan pulse Vout2 is not included in the time corresponding to the effective charging section B of the second scan pulse Vout2, and the second scan pulse Vout2 is not included in the time period. Since it is included in the time corresponding to the preliminary charging section A, the time corresponding to the effective charging section B of the first scan pulse Vout1 is not reduced by the rising time TR.

Therefore, as shown in FIGS. 6A and 6B, the first and second scan pulses Vout1 and Vout2 of the present invention are conventional first and second scan pulses Vout1` and Vout2`. Effective charge time (TS) longer than In this case, the effective charging time TS of the first and second scan pulses Vout1 and Vout2 of the present invention is longer than the time 1H at which the data voltage Data is maintained as positive and negative polarity. The voltage Data is normally transmitted to the pixel electrode.

On the other hand, since the scan pulses Vout1 to Voutn output in adjacent time zones have overlapping pulse width sections, when the scan pulses output from the next stage are input to each stage BST1 to BSTn + 2 as in the prior art, The following problems may occur. That is, for example, since the first scan pulse Vout1 and the second scan pulse Vout2 output in adjacent time zones have pulse width sections overlapping each other, the output from the second stage BST2 as in the prior art. When the second scan pulse Vout2 is input to the first stage BST1 that outputs the first scan pulse Vout1, the first stage BST1 corresponds to the effective charge section B of its own. The third voltage source VSS is supplied to the first gate line at. In other words, when the first stage BST1 outputs the second scan pulse Vout2 even before the first scan pulse Vout1 is completely applied to the first gate line (specifically, the second scan pulse). The third voltage source VSS is supplied to the first gate line at the point corresponding to the precharge period A of Vout2. Therefore, the first stage BST1 may output an incomplete scan pulse. Then, scan pulses having the same pulse width as the conventional gate lines are supplied to each gate line, and thus, each scan pulse Vout1 to Voutn may be distorted. For this reason, each stage BST1 to BSTn + 2 according to the present invention receives a scan pulse from the next stage instead of the next stage. That is, each of the stages BST1 to BSTn + 2 receives a scan pulse having no section overlapping with the scan pulse output from the stage.

Here, a circuit configured in each of the stages BST1 to BSTn + 2 and the first and second dummy stages BSTn + 1 and BSTn + 2 will be described in detail. Meanwhile, since the circuit configurations of the stages, the first and second dummy stages BSTn + 1 and BSTn + 2 are all the same, only the third stage BST3 will be described as an example.

FIG. 7 is a circuit diagram illustrating the third stage of FIG. 3.

As illustrated in FIG. 7, the third stage BST3 includes a node controller 700a which controls charging and discharging of the first, second, and third nodes Q, QB1, and QB2. The output unit 700b is turned on according to the charge / discharge states of the first, second, and third nodes Q, QB1, and QB2 to selectively output a scan pulse or a third voltage source VSS. Here, the first, second, and third nodes Q, QB1, and QB2 are selectively charged and discharged. Specifically, when the first node Q is in a charged state, the second node QB1 is charged. And both the third node QB2 maintains a discharge state, and when the first node Q is in a discharge state, any one of the second node QB1 and the third node QB2 maintains a discharge state. . That is, in the odd-numbered frame, when the first node Q is in the discharged state, the second node QB1 is charged, the third node QB2 is discharged, and in the even-numbered frame, the first node is discharged. When Q is in the discharged state, the second node QB1 is discharged and the third node QB2 is charged. As such, when the first node Q is in the discharged state, the voltage sources VDD1 and VDD2 having different polarities are applied (charged and discharged) to the second node QB1 and the third node QB2 for each frame. The reason is to prevent deterioration of the switching device having the gate terminal connected to the second node QB1 and the third node QB2.

The node control unit 700a of the third stage BST3 includes first to tenth NMOS transistors Tr1 to Tr10.

The first NMOS transistor Tr1 charges the first node Q with the scan pulse in response to the scan pulse from the previous stage. That is, the first NMOS transistor Tr1 charges the first node Q to the second scan pulse Vout2 in response to the second scan pulse Vout2 from the second stage BST2. To this end, the gate terminal of the first NMOS transistor Tr1 is connected to the output 700b of the second stage BST2, the source terminal is connected to the second stage BST2, and the drain terminal is It is connected to the first node Q.

The second NMOS transistor Tr2 discharges the second node QB1 to the third voltage source in response to the second scan pulse Vout2 charged in the first node Q. To this end, a gate terminal of the second NMOS transistor Tr2 is connected to the first node Q, a source terminal is connected to the second node QB1, and a drain terminal transmits the third voltage source. It is connected to the power line.

The third NMOS transistor Tr3 discharges the third node QB2 to the third voltage source VSS in response to the second scan pulse Vout2 charged in the first node Q. To this end, the gate terminal of the third NMOS transistor Tr3 is connected to the first node Q, the source terminal is connected to the third node QB2, and the drain terminal is connected to the third voltage source VSS. It is connected to the power line to transmit.

The fourth NMOS transistor Tr4 is turned on or turned off in response to the first voltage source VDD1 having a different polarity for each frame, and turns the second node QB1 to the first voltage source VDD1. Charge with. To this end, the gate terminal of the fourth NMOS transistor Tr4 is connected to a power line for transmitting the first voltage source VDD1, and the source terminal is connected to a power line for transmitting the first voltage source VDD1. The drain terminal is connected to the second node QB1.

The fifth NMOS transistor Tr5 discharges the first node Q to the third voltage source VSS in response to the first voltage source VDD1 charged in the second node QB1. To this end, the gate terminal of the fifth NMOS transistor Tr5 is connected to the second node QB1, the source terminal is connected to the first node Q, and the drain terminal of the third voltage source VSS. It is connected to the power line to transmit.

The sixth NMOS transistor Tr6 is turned on or turned off in response to the first voltage source VDD1, and discharges the third node QB2 to the third voltage source VSS when turned on. To this end, the gate terminal of the sixth NMOS transistor Tr6 is connected to a power line for transmitting the first voltage source VDD1, the source terminal is connected to the third node QB2, and the drain terminal is connected to the third terminal QB2. 3 is connected to the power line for transmitting the voltage source (VSS).

The seventh NMOS transistor Tr7 is turned on or off in response to the second voltage source VDD2 having a different polarity for each frame, and turns the third node QB2 to the second voltage source VDD2. ) To this end, a gate terminal of the seventh NMOS transistor Tr7 is connected to a power line for transmitting the second voltage source VDD2, a source terminal is connected to a power line for transmitting the second voltage source VDD2, The drain terminal is connected to the third node QB2. Here, the second voltage source VDD2 has an inverted phase with the first voltage source VDD1.

The eighth NMOS transistor Tr8 discharges the first node Q to the third voltage source VSS in response to the second voltage source VDD2 charged in the third node QB2. To this end, the gate terminal of the eighth NMOS transistor Tr8 is connected to the third node QB2, the source terminal is connected to the first node Q, and the drain terminal of the third voltage source VSS. It is connected to the power line to transmit.

The ninth NMOS transistor Tr9 is turned on or turned off in response to the second voltage source VDD2, and discharges the second node QB1 to the third voltage source VSS when turned on. To this end, a gate terminal of the ninth NMOS transistor Tr9 is connected to a power line for transmitting the second voltage source VDD2, a source terminal is connected to the second node QB1, and a drain terminal is connected to the second terminal QB1. 3 is connected to the power line for transmitting the voltage source (VSS).

The tenth NMOS transistor Tr10 discharges the first node Q to the third voltage source VSS in response to the scan pulse from the next stage. That is, the tenth NMOS transistor Tr10 discharges the first node Q to the third voltage source VSS in response to the fifth scan pulse Vout5 from the fifth stage. To this end, a gate terminal of the tenth NMOS transistor Tr10 is connected to the fifth stage, a source terminal is connected to the first node Q, and a drain terminal transmits the third voltage source VSS. It is connected to the power line.

The output part 700b of the third stage BST3 includes the eleventh through thirteenth NMOS transistors Tr11 through Tr13.

The eleventh NMOS transistor Tr11 outputs the clock pulse as the third scan pulse Vout3 to the gate line in response to the second scan pulse Vout2 charged in the first node Q. The third scan pulse Vout3 is supplied to both the front stage (i.e., the first stage BST1) and the next stage (i.e., the fourth stage BST4). To this end, the gate terminal of the eleventh NMOS transistor Tr11 is connected to the first node Q, the source terminal is connected to the clock line for transmitting the third clock pulse CLK3, and the drain terminal is connected to the third gate. A line, a gate terminal of the tenth NMOS transistor Tr10 provided in the first stage BST1, and a gate terminal of the first NMOS transistor Tr1 provided in the fourth stage BST4.

The twelfth NMOS transistor Tr12 supplies the third voltage source VSS to the gate line in response to the first voltage source VDD1 charged in the second node QB1. That is, the twelfth NMOS transistor Tr12 supplies the third voltage source VSS to the third gate line in response to the first voltage source VDD1 charged in the second node QB1. To this end, the gate terminal of the twelfth NMOS transistor Tr12 is connected to the second node QB1, the drain terminal is connected to a power line for transmitting the third voltage source VSS, and the source terminal is connected to the third gate line. And the gate terminal of the tenth NMOS transistor Tr10 provided in the first stage BST1, and the gate terminal of the first NMOS transistor Tr1 provided in the fourth stage BST4.

The thirteenth NMOS transistor Tr13 supplies the third voltage source VSS to the gate line in response to the second voltage source VDD2 charged in the third node QB2. That is, the thirteenth NMOS transistor Tr13 supplies the third voltage source VSS to the third gate line in response to the second voltage source VDD2 charged in the third node QB2. To this end, the gate terminal of the thirteenth NMOS transistor Tr13 is connected to the second node QB1, the drain terminal is connected to a power line for transmitting the third voltage source VSS, and the source terminal is connected to the second gate line. And the gate terminal of the tenth NMOS transistor Tr10 provided in the first stage BST1, and the gate terminal of the first NMOS transistor Tr1 provided in the fourth stage BST4.

The first and second stages BST1 and BST2, the fourth to nth stages BST4 to BSTn, and the first and second dummy stages BSTn + 1 and BSTn + 2 are also described above. Has the same configuration as

However, since the stage does not exist before the first stage BST1, the first NMOS transistor Tr1 included in the first stage BST1 receives the start pulse SP from the timing controller. That is, the first NMOS transistor Tr1 of the first stage BST1 charges the first node Q of the first stage BST1 in response to the start pulse SP from the timing controller. .

The stage does not exist at the front ends of the first and second stages BST1 and BST2. Therefore, the first stage BST1 outputs the first scan pulse Vout1 and supplies it to the first gate line and the second stage BST2. Similarly, the second stage BST2 outputs the second scan pulse Vout2 and supplies it to the second gate line and the third stage BST3.

There is no stage next to the second dummy stage BSTn + 2. Therefore, the source terminal of the eleventh NMOS transistor Tr11 of the second dummy stage BSTn + 2, the drain terminal of the twelfth NMOS transistor Tr12, and the drain terminal of the thirteenth NMOS transistor Tr13 are n-th. The gate terminal of the tenth NMOS transistor Tr10 of the stage BSTn is connected.

Meanwhile, it is preferable to use an amorphous TFT (Thin Film Transistor) as the first to thirteen NMOS transistors Tr1 to Tr13. The stages are preferably embedded in the liquid crystal panel.

The operation of the shift register according to the first embodiment of the present invention configured as described above is as follows.

8A and 8B show first to third stages having the circuit configuration of FIG.

First, the operation during the first frame will be described.

Here, it is assumed that the first voltage source VDD1 is maintained at the positive voltage during the first frame, and the second voltage source VDD2 is maintained at the negative voltage, and the first voltage source VDD1 is negative during the second frame. It is assumed that the voltage is maintained at the polarity and the second voltage source VDD2 is maintained at the voltage of the positive polarity. That is, it is assumed that the first voltage source VDD1 remains positive and the second voltage source VDD2 remains negative during an odd frame, and the first voltage source VDD1 becomes negative during an even frame. It is assumed that the second voltage source VDD2 remains positive.

First, the start pulse SP is applied to the gate terminal of the first NMOS transistor Tr1 of the first stage BST1 to turn on the first NMOS transistor Tr1. Here, the start pulse SP is supplied to the first node Q through the turned-on first NMOS transistor Tr1. In this case, as the first node Q is charged with the start pulse SP, the second, third, and eleventh NMOS transistors Tr2, Tr3, which have gate terminals connected to the first node Q, are connected. Tr11) is turned on.

At this time, the third voltage source VSS is supplied to the second node QB1 through the turned-on second NMOS transistor Tr2. Here, the first voltage source VDD1 is supplied to the second node QB1 through the fourth NMOS transistor Tr4. Since the first voltage source VDD1 maintains positive polarity during the first frame, the fourth NMOS transistor Tr4, which receives the first voltage source VDD1 through the gate terminal, is turned on for the first frame. do.

As such, the third voltage source VSS and the first voltage source VDD1 are supplied to the second node QB1 together. However, since the channel width of the second NMOS transistor Tr2 for supplying the third voltage source VSS is set larger than the channel width of the fourth NMOS transistor Tr4 for supplying the first voltage source VDD1, The second node QB1 is maintained as a third voltage source VSS. Accordingly, the second node QB1 is discharged. Accordingly, the fifth and twelfth NMOS transistors Tr5 and Tr12 having gate terminals connected to the second node QB1 are turned off. On the other hand, since the second voltage source VDD2 maintains negative polarity during the first frame, the ninth NMOS transistor Tr9 to which the second voltage source VDD2 is supplied to the gate terminal remains turned off for the first frame. do.

Meanwhile, a third voltage source VSS is supplied to the third node QB2 through the turned-on third NMOS transistor Tr3. As a result, the third node QB2 is discharged. In addition, the third node QB2 is discharged by the sixth NMOS transistor Tr6. That is, the sixth NMOS transistor Tr6, which receives the first voltage source VDD1 through the gate terminal, is turned on for the first frame, so that the turned-on sixth NMOS transistor Tr6 is turned on. The third node QB2 is discharged to the third voltage source VSS. Therefore, the eighth and thirteenth NMOS transistors Tr8 and Tr13 having gate terminals connected to the third node QB2 are turned off.

In this manner, the first node Q of the first stage BST1 is charged by the start pulse SP, and the second and third nodes QB1 and QB2 are discharged. That is, the first stage BST1 is enabled by the start pulse SP. In this state, when the first clock pulse CLK1 is supplied to the eleventh NMOS transistor Tr11 of the first stage BST1, the eleventh NMOS transistor Tr11 removes the first clock pulse CLK1. Outputs as one scan pulse (Vout1). In this case, since the first clock pulse CLK1 and the start pulse SP are superimposed and output, the first scan pulse Vout1 is superimposed on the start pulse SP and output.

The first scan pulse Vout1 is supplied to the first gate line and the second stage BST2. That is, the first scan pulse Vout1 from the first stage BST1 is supplied to the first NMOS transistor Tr1 of the second stage BST2. Accordingly, the first node Q of the second stage BST2 is charged, and the second and third nodes QB1 and QB2 are discharged. That is, the second stage BST2 is enabled by the first scan pulse Vout1. In other words, as the first stage BST1 is enabled by the start pulse SP, the second stage BST2 is enabled by the first scan pulse Vout1. In this state, when the second clock pulse CLK2 is supplied to the eleventh NMOS transistor Tr11 of the second stage BST2, the eleventh NMOS transistor Tr11 removes the second clock pulse CLK2. Outputs as 2 scan pulses (Vout2). In this case, since the second clock pulse CLK2 overlaps the first clock pulse CLK1, the second scan pulse Vout2 is output to overlap the first scan pulse Vout1.

The second scan pulse Vout2 is supplied to the second gate line and the third stage BST3. That is, the second scan pulse Vout2 from the second stage BST2 is supplied to the first NMOS transistor Tr1 of the third stage BST3. As a result, the first node Q of the third stage BST3 is charged, and the second and third nodes QB1 and QB2 are discharged. That is, the third stage BST3 is enabled by the second scan pulse Vout2. In other words, as the first stage BST1 is enabled by the start pulse SP, the third stage BST3 is enabled by the second scan pulse Vout2.

In this state, when the third clock pulse CLK3 is supplied to the eleventh NMOS transistor Tr11 of the third stage BST3, the eleventh NMOS transistor Tr11 removes the third clock pulse CLK3. Outputs as 3 scan pulses (Vout3). In this case, since the third clock pulse CLK3 overlaps the second clock pulse CLK2, the third scan pulse Vout3 is output to overlap the second scan pulse Vout2.

The third scan pulse Vout3 is supplied to the third gate line and the fourth stage BST4. That is, the third scan pulse Vout3 from the third stage BST3 is supplied to the first NMOS transistor Tr1 of the fourth stage BST4. Accordingly, the first node Q of the fourth stage BST4 is charged and the second and third nodes QB1 and QB2 are discharged. That is, the fourth stage BST4 is enabled by the third scan pulse Vout3. In other words, as the first stage BST1 is enabled by the start pulse SP, the fourth stage BST4 is enabled by the third scan pulse Vout3.

In this state, when the fourth clock pulse CLK4 is supplied to the eleventh NMOS transistor Tr11 of the fourth stage BST4, the eleventh NMOS transistor Tr11 removes the fourth clock pulse CLK4. Outputs as 4 scan pulses (Vout4). In this case, since the fourth clock pulse CLK4 overlaps the third clock pulse CLK3, the fourth scan pulse Vout4 is output to overlap the third scan pulse Vout3.

The third scan pulse Vout3 output from the third stage BST3 is also supplied to the tenth NMOS transistor Tr10 of the first stage BST1. That is, the third scan pulse Vout3 is supplied to the gate terminal of the tenth NMOS transistor Tr10 provided in the first stage BST1. Accordingly, the first stage BST1 is disabled.

Specifically, the third scan pulse Vout3 turns on the tenth NMOS transistor Tr10 provided in the first stage BST1. Then, the third voltage source VSS is supplied to the first node Q of the first stage BST1 through the turned-on tenth NMOS transistor Tr10. Accordingly, the first node Q of the first stage BST1 is discharged. Therefore, the second, third, and eleventh NMOS transistors Tr2, Tr3, and Tr11 connected to the first node Q of the first stage BST1 are turned off.

Here, as the second NMOS transistor Tr2 of the first stage BST1 is turned off, the second node QB1 of the first stage BST1 is applied through the fourth NMOS transistor Tr4. The first voltage source VDD1 is charged. Accordingly, the fifth and twelfth NMOS transistors Tr5 and Tr12 having gate terminals connected to the second node QB1 of the first stage BST1 are turned on. In this case, a third voltage source VSS is supplied to the first node Q of the first stage BST1 through the turned-on fifth NMOS transistor Tr5. Accordingly, the first node Q of the first stage BST1 is discharged at a high speed.

Meanwhile, the third node QB2 of the first stage BST1 maintains a discharge state by the third voltage source VSS applied through the turned-on sixth NMOS transistor Tr6.

In this way, the first node Q and the third node QB2 of the first stage BST1 are discharged by the third scan pulse Vout3 from the third stage BST3, and the second node ( QB1) is charged. That is, the first stage BST1 is disabled in response to the third scan pulse Vout3 from the third stage BST3. The disabled first stage BST1 outputs the third voltage source VSS through the twelfth NMOS transistor Tr12 provided therein. Then, the third voltage source VSS is supplied to the first gate line.

In this manner, each stage BST1 to BSTn + 2 is enabled by a scan pulse output from the previous stage from itself. Then, each stage BST1 to BSTn + 2 is disabled by the scan pulse from the stage located next to it.

On the other hand, the first voltage source VDD1 is maintained at the negative polarity and the second voltage source VDD2 is maintained at the positive polarity in the second frame. As a result, when the stages BST1 to BSTn + 2 are disabled, the second node QB1 of each stage BST1 to BSTn + 2 is discharged and the third node QB2 is charged. Therefore, when each of the stages BST1 to BSTn + 2 is disabled, the third voltage source VSS is output through the thirteenth NMOS transistor Tr13 having a gate terminal connected to the third node QB2. As such, since the second and third nodes QB1 and QB2 are alternately charged / discharged for each frame, deterioration of the twelfth and thirteenth NMOS transistors Tr12 and Tr13 included in the output unit 700b is performed. Can be prevented.

Meanwhile, each of the stages BST1 to BSTn + 2 may have a circuit configuration as follows.

FIG. 9 is another circuit diagram illustrating the third stage of FIG. 3.

The third stage BST3 of FIG. 9 also includes the node control unit 900a and the output unit 900b as described above.

The node control unit 900a of the third stage BST3 includes first to sixteenth NMOS transistors Tr1 to Tr16.

The first NMOS transistor Tr1 charges the first node Q with the scan pulse in response to the scan pulse from the previous stage. That is, the first NMOS transistor Tr1 charges the first node Q to the second scan pulse Vout2 in response to the second scan pulse Vout2 from the second stage BST2. To this end, the gate terminal of the first NMOS transistor Tr1 is connected to the second stage BST2, the source terminal is connected to the second stage BST2, and the drain terminal is connected to the first node Q. Is connected to.

The second NMOS transistor Tr2 discharges the second node QB1 to the third voltage source VSS in response to the second scan pulse Vout2 charged in the first node Q. To this end, the gate terminal of the second NMOS transistor Tr2 is connected to the first node Q, the source terminal is connected to the second node QB1, and the drain terminal is connected to the third voltage source VSS. It is connected to the power line to transmit.

The third NMOS transistor Tr3 discharges the third node QB2 to the third voltage source VSS in response to the second scan pulse Vout2 charged in the first node Q. To this end, the gate terminal of the third NMOS transistor Tr3 is connected to the first node Q, the source terminal is connected to the third node QB2, and the drain terminal is connected to the third voltage source VSS. It is connected to the power line to transmit.

The fourth NMOS transistor Tr4 discharges the second node QB1 to the third voltage source VSS in response to the scan pulse from the previous stage. That is, the fourth NMOS transistor Tr4 discharges the second node QB1 to the second voltage source VDD2 in response to the second scan pulse Vout2 from the second stage BST2. To this end, the gate terminal of the fourth NMOS transistor Tr4 is connected to the second stage BST2, the source terminal is connected to the second node QB1, and the drain terminal of the fourth voltage source VSS is connected to the second node QB1. It is connected to the transmitting power line.

The fifth NMOS transistor Tr5 discharges the third node QB2 to the third voltage source VSS in response to the scan pulse from the previous stage. That is, the fifth NMOS transistor Tr5 discharges the third node QB2 to the third voltage source VSS in response to the second scan pulse Vout2 from the second stage BST2. To this end, the gate terminal of the fifth NMOS transistor Tr5 is connected to the second stage BST2, the source terminal is connected to the third node QB2, and the drain terminal of the fifth voltage source VSS is connected. It is connected to the transmitting power line.

The sixth NMOS transistor Tr6 is turned on or off in response to the first voltage source VDD1 having a different polarity for each frame, and outputs the first voltage source VDD1 at turn-on. To this end, the gate terminal of the sixth NMOS transistor Tr6 is connected to a power line for transmitting the first voltage source VDD1, and the source terminal is connected to a power line for transmitting the first voltage source VDD1.

The seventh NMOS transistor Tr7 charges the second node QB1 to the first voltage source VDD1 in response to the first voltage source VDD1 output from the sixth NMOS transistor Tr6. To this end, the gate terminal of the seventh NMOS transistor Tr7 is connected to the drain terminal of the sixth NMOS transistor Tr6, the source terminal is connected to a power line for transmitting the first voltage source VDD1, and the drain The terminal is connected to the second node QB1.

The eighth NMOS transistor Tr8 discharges the first node Q to the third voltage source VSS in response to the first voltage source VDD1 charged in the second node QB1. To this end, a gate terminal of the eighth NMOS transistor Tr8 is connected to the second node QB1, a source terminal is connected to the first node Q, and a drain terminal of the eighth NMOS transistor Tr8 is connected to the third voltage source VSS. It is connected to the transmitting power line.

The ninth NMOS transistor Tr9 supplies the third voltage source VSS to the gate terminal of the seventh NMOS transistor Tr7 in response to the second scan pulse Vout2 charged in the first node Q. The seventh NMOS transistor Tr7 is turned off. For this purpose, the gate terminal of the ninth NMOS transistor Tr9 is connected to the first node Q, the source terminal is connected to the gate terminal of the seventh NMOS transistor Tr7, and the drain terminal is connected to the third terminal. It is connected to a power supply line that transmits a voltage source VSS.

The tenth NMOS transistor Tr10 turns on the seventh NMOS transistor Tr7 by supplying a third voltage source VSS to the gate terminal of the seventh NMOS transistor Tr7 in response to the scan pulse from the previous stage. -Turn it off. That is, the tenth NMOS transistor Tr10 applies the third voltage source VSS to the gate terminal of the seventh NMOS transistor Tr7 in response to the second scan pulse Vout2 from the second stage BST2. The seventh NMOS transistor Tr7 is turned off by the supply. To this end, the gate terminal of the tenth NMOS transistor Tr10 is connected to the second stage BST2, the source terminal is connected to the gate terminal of the seventh NMOS transistor Tr7, and the drain terminal of the third NMOS transistor Tr10. It is connected to a power supply line that transmits a voltage source VSS.

The eleventh NMOS transistor Tr11 is turned on or off in response to the second voltage source VDD2 having a different polarity for each frame, and outputs the second voltage source VDD2 when turned on. To this end, the gate terminal of the eleventh NMOS transistor Tr11 is connected to a power line for transmitting the second voltage source VDD2, and the source terminal is connected to a power line for transmitting the second voltage source VDD2. Here, the second voltage source VDD2 has an inverted polarity with respect to the first voltage source VDD1 every frame.

The twelfth NMOS transistor Tr12 charges the third node QB2 to the second voltage source VDD2 in response to the second voltage source VDD2 output from the eleventh NMOS transistor Tr11. To this end, the gate terminal of the twelfth NMOS transistor Tr12 is connected to the drain terminal of the eleventh NMOS transistor Tr11, and the source terminal is connected to a power line for transmitting the second voltage source VDD2. The terminal is connected to the third node QB2.

The thirteenth NMOS transistor Tr13 discharges the first node Q to the third voltage source VSS in response to the second voltage source VDD2 charged in the third node QB2. To this end, a gate terminal of the thirteenth NMOS transistor Tr13 is connected to the third node QB2, a source terminal is connected to the first node Q, and a drain terminal of the third voltage source VSS is connected to the third node QB2. It is connected to the transmitting power line.

The fourteenth NMOS transistor Tr14 supplies a third voltage source VSS to the gate terminal of the twelfth NMOS transistor Tr12 in response to the second scan pulse Vout2 charged in the first node Q. The twelfth NMOS transistor Tr12 is turned off. For this purpose, a gate terminal of the fourteenth NMOS transistor Tr14 is connected to the first node Q, a source terminal is connected to a gate terminal of the twelfth NMOS transistor Tr12, and a drain terminal of the third It is connected to a power supply line that transmits a voltage source VSS.

The fifteenth NMOS transistor Tr15 supplies the third voltage source VSS to the gate terminal of the twelfth NMOS transistor Tr12 in response to the scan pulse from the previous stage, thereby supplying the twelfth NMOS transistor Tr12. Turn off. That is, the fifteenth NMOS transistor Tr15 turns off the twelfth NMOS transistor Tr12 in response to the second scan pulse Vout2 from the second stage BST2. To this end, the gate terminal of the fifteenth NMOS transistor Tr15 is connected to the second stage BST2, the source terminal is connected to the gate terminal of the twelfth NMOS transistor Tr12, and the drain terminal of the third NMOS transistor Tr15 is connected to the third terminal. It is connected to a power supply line that transmits a voltage source VSS.

The sixteenth NMOS transistor Tr16 discharges the first node Q to the third voltage source VSS in response to the scan pulse from the next stage. That is, the gate terminal of the sixteenth NMOS transistor Tr16 discharges the first node Q to the third voltage source VSS in response to the fifth scan pulse Vout5 from the fifth stage. To this end, a gate terminal of the sixteenth NMOS transistor Tr16 is connected to the fifth stage, a source terminal is connected to the first node Q, and a drain terminal transmits the third voltage source VSS. It is connected to the power line.

The output unit 900b of the second stage BST2 includes the seventeenth through nineteenth NMOS transistors Tr17 through Tr19.

The seventeenth NMOS transistor Tr17 sets the third clock pulse CLK3 as the third scan pulse Vout3 to the third gate line in response to the second scan pulse Vout2 charged in the first node Q. Output The third scan pulse Vout3 is supplied to both the front stage and the next stage. For this purpose, the gate terminal of the seventeenth NMOS transistor Tr17 is connected to the first node Q, the source terminal is connected to the clock line for transmitting the third clock pulse CLK3, and the drain terminal is connected to the third gate. Lines, gate terminals of the sixteenth NMOS transistor Tr16 provided in the first stage BST1, and first, fourth, fifth, tenth, and fifteenth NMOS transistors provided in the fourth stage BST4 ( It is connected to the gate terminals of Tr1, Tr4, Tr5, Tr10, and Tr15.

The eighteenth NMOS transistor Tr18 supplies the third voltage source VSS to the gate line in response to the first voltage source VDD1 charged in the second node QB1. That is, the eighteenth NMOS transistor Tr18 supplies the third voltage source VSS to the third gate line in response to the first voltage source VDD1 charged in the second node QB1. To this end, the gate terminal of the eighteenth NMOS transistor Tr18 is connected to the second node QB1, the drain terminal is connected to a power line for transmitting the third voltage source VSS, and the source terminal is connected to the second gate line. , Gate terminals of the sixteenth NMOS transistor Tr16 provided in the first stage BST1, and first, fourth, fifth, tenth, and fifteenth NMOS transistors Tr1 provided in the fourth stage BST4. And Tr4, Tr5, Tr10, and Tr15.

The nineteenth NMOS transistor Tr19 supplies the third voltage source VSS to the gate line in response to the second voltage source VDD2 charged in the third node QB2. That is, the nineteenth NMOS transistor Tr19 supplies the third voltage source VSS to the third gate line in response to the second voltage source VDD2 charged in the third node QB2. For this purpose, the gate terminal of the nineteenth NMOS transistor Tr19 is connected to the second node QB1, the drain terminal is connected to a power line for transmitting the third voltage source VSS, and the source terminal is connected to the second gate line. , Gate terminals of the sixteenth NMOS transistor Tr16 provided in the first stage BST1, and first, fourth, fifth, tenth, and fifteenth NMOS transistors Tr1 provided in the fourth stage BST4. And Tr4, Tr5, Tr10, and Tr15.

The first and second stages BST1 and BST2, the fourth to nth stages BST4 to BSTn, and the first and second dummy stages BSTn + 1 and BSTn + 2 are also described above. Has the same configuration as

However, since there is no stage before the first stage BST1, the first, fourth, fifth, tenth, and fifteenth NMOS transistors Tr1 and Tr4 included in the first stage BST1 are provided. , Tr5, Tr10, Tr15 are supplied with a start pulse SP from the timing controller. That is, the first NMOS transistor Tr1 of the first stage BST1 receives the first node Q of the first stage BST1 in response to the start pulse SP from the timing controller. Charged to voltage source VDD1. The fourth NMOS transistor Tr4 discharges the second node QB1 of the first stage BST1 to the second voltage source VDD2 in response to the start pulse SP from the timing controller. . The fifth NMOS transistor Tr5 discharges the third node QB2 of the first stage BST1 to the second voltage source VDD2 in response to the start pulse SP from the timing controller. . The tenth NMOS transistor Tr10 turns off the seventh NMOS transistor Tr7 included in the first stage BST1 in response to the start pulse SP from the timing controller. The fifteenth NMOS transistor Tr15 turns off the twelfth NMOS transistor Tr12 included in the first stage BST1 in response to the start pulse SP from the timing controller.

In addition, there is no stage at the front ends of the first and second stages BST1 and BST2. Therefore, the first stage BST1 outputs the first scan pulse Vout1 and supplies it to the first gate line and the second stage BST2. Similarly, the second stage BST2 outputs the second scan pulse Vout2 and supplies it to the second gate line and the third stage BST3.

In addition, there is no stage next to the second dummy stage BSTn + 2. Therefore, the source terminal of the seventeenth NMOS transistor Tr17 of the second dummy stage BSTn + 2, the drain terminal of the eighteenth NMOS transistor Tr18, and the drain terminal of the nineteenth NMOS transistor Tr19 are n-th. It is connected to the gate terminal of the sixteenth NMOS transistor Tr16 of the stage BSTn.

On the other hand, the first to 19 NMOS transistors (Tr1 to Tr19) it is preferable to use an amorphous TFT (Thin Film Transistor). The stages are preferably embedded in the liquid crystal panel.

The operation of the shift register according to the first embodiment of the present invention configured as described above is as follows.

10A and 10B are diagrams illustrating first to third stages BST3 having the circuit configuration of FIG. 9.

First, the operation during the first frame will be described.

Here, it is assumed that the first voltage source VDD1 is maintained at the positive voltage during the first frame, and the second voltage source VDD2 is maintained at the negative voltage. It is assumed that it is maintained at a negative voltage and the second voltage source VDD2 is maintained at a positive voltage. That is, it is assumed that the first voltage source VDD1 remains positive and the second voltage source VDD2 remains negative during an odd frame, and the first voltage source VDD1 becomes negative during an even frame. It is assumed that the second voltage source VDD2 remains positive.

First, the start pulse SP turns on the first, fourth, fifth, tenth, and fifteenth NMOS transistors Tr1, Tr4, Tr5, Tr10, and Tr15 of the first stage BST1. Then, the start pulse SP is supplied to the first node Q through the turned-on first NMOS transistor Tr1. In this case, as the first node Q is charged with the start pulse SP, second, third, ninth, fourteenth, and seventeenth NMOSs having gate terminals connected to the first node Q, respectively. Transistors Tr2, Tr3, Tr9, Tr14, and Tr17 are turned on.

The third voltage source VSS is supplied to the second node QB1 through the turned-on second and fourth NMOS transistors Tr2 and Tr4. Accordingly, the second node QB1 is discharged, and the eighth and eighteenth NMOS transistors Tr8 and Tr18 having gate terminals connected to the second node QB1 are turned off.

The third voltage source VSS is supplied to the third node QB2 through the turned-on third and fifth NMOS transistors Tr3 and Tr5. Accordingly, the third node QB2 is discharged, and the thirteenth and nineteenth NMOS transistors Tr13 and Tr19 having gate terminals connected to the third node QB2 are turned off.

The third voltage source VSS is supplied to the gate terminal of the seventh NMOS transistor Tr7 through the turned-on ninth and tenth NMOS transistors Tr9 and Tr10. In addition, the first voltage source VDD1 is connected to the seventh NMOS transistor Tr7 through the sixth NMOS transistor Tr6, which is always turned on during the first frame by the positive first voltage source VDD1. It is supplied to the gate terminal of. Therefore, the third voltage source VSS and the first voltage source VDD1 are supplied together to the gate terminal of the seventh NMOS transistor Tr7. In this case, the number of transistors supplying the third voltage source VSS to the gate terminal of the seventh NMOS transistor Tr7 is the number of transistors supplying the first voltage source VDD1 to the gate terminal of the seventh NMOS transistor Tr7. Since more, the gate terminal of the seventh NMOS transistor Tr7 is maintained as a third voltage source VSS. Thus, the seventh NMOS transistor Tr7 is turned off.

The third voltage source VSS is supplied to the gate terminal of the twelfth NMOS transistor Tr12 through the turned-on fourteenth and fifteenth NMOS transistors Tr14 and Tr15. Thus, the twelfth NMOS transistor Tr12 is turned off. Meanwhile, the eleventh NMOS transistor Tr11 is always turned off for one frame by the negative voltage source VDD2.

In this manner, the first node Q of the first stage BST1 is charged by the start pulse SP, and the second and third nodes QB1 and QB2 are discharged. That is, the first stage BST1 is enabled by the start pulse SP. In this state, when the first clock pulse CLK1 is supplied to the seventeenth NMOS transistor Tr17 of the first stage BST1, the seventeenth NMOS transistor Tr17 removes the first clock pulse CLK1. Outputs as one scan pulse (Vout1). In this case, since the first clock pulse CLK1 and the start pulse SP are superimposed and output, the first scan pulse Vout1 is superimposed on the start pulse SP and output.

The first scan pulse Vout1 is supplied to the first gate line and the second stage BST2. That is, the first scan pulse Vout1 from the first stage BST1 is configured to include the first, fourth, fifth, tenth, and fifteenth NMOS transistors Tr1, Tr4, Tr5, and the second stage BST2. Tr10 and Tr15). Accordingly, the first node Q of the second stage BST2 is charged, and the second and third nodes QB1 and QB2 are discharged. That is, the second stage BST2 is enabled by the first scan pulse Vout1. In other words, as the first stage BST1 is enabled by the start pulse SP, the second stage BST2 is enabled by the first scan pulse Vout1. In this state, when the second clock pulse CLK2 is supplied to the seventeenth NMOS transistor Tr17 of the second stage BST2, the seventeenth NMOS transistor Tr17 removes the second clock pulse CLK2. Outputs as 2 scan pulses (Vout2). In this case, since the second clock pulse CLK2 overlaps the first clock pulse CLK1, the second scan pulse Vout2 is output to overlap the first scan pulse Vout1.

The second scan pulse Vout2 is supplied to the second gate line and the third stage BST3. In other words, the second scan pulse Vout2 from the second stage BST2 is configured as the first, fourth, fifth, tenth, and fifteenth NMOS transistors Tr1, Tr4, Tr5, and the third stage BST3. Tr10 and Tr15). As a result, the first node Q of the third stage BST3 is charged, and the second and third nodes QB1 and QB2 are discharged. That is, the third stage BST3 is enabled by the second scan pulse Vout2. In other words, as the first stage BST1 is enabled by the start pulse SP, the third stage BST3 is enabled by the second scan pulse Vout2.

In this state, when the third clock pulse CLK3 is supplied to the seventeenth NMOS transistor Tr17 of the third stage BST3, the seventeenth NMOS transistor Tr17 removes the third clock pulse CLK3. Outputs as 3 scan pulses (Vout3). In this case, since the third clock pulse CLK3 overlaps the second clock pulse CLK2, the third scan pulse Vout3 is output to overlap the second scan pulse Vout2.

The third scan pulse Vout3 is supplied to the third gate line and the fourth stage BST4. That is, the first scan pulse Vout1 from the third stage BST3 includes the first, fourth, fifth, tenth, and fifteenth NMOS transistors Tr1, Tr4, Tr5, and the fourth stage BST4. Tr10 and Tr15). Accordingly, the first node Q of the fourth stage BST4 is charged and the second and third nodes QB1 and QB2 are discharged. That is, the fourth stage BST4 is enabled by the first scan pulse Vout1. In other words, as the first stage BST1 is enabled by the start pulse SP, the fourth stage BST4 is enabled by the third scan pulse Vout3.

In this state, when the fourth clock pulse CLK4 is supplied to the seventeenth NMOS transistor Tr17 of the fourth stage BST4, the seventeenth NMOS transistor Tr17 removes the fourth clock pulse CLK4. Outputs as 4 scan pulses (Vout4). In this case, since the fourth clock pulse CLK4 overlaps the third clock pulse CLK3, the fourth scan pulse Vout4 is output to overlap the third scan pulse Vout3.

On the other hand, the third scan pulse Vout3 output from the third stage BST3 is also supplied to the sixteenth NMOS transistor Tr16 of the first stage BST1. That is, the third scan pulse Vout3 is supplied to the gate terminal of the sixteenth NMOS transistor Tr16 provided in the first stage BST1. Accordingly, the first stage BST1 is disabled.

Specifically, the third scan pulse Vout3 turns on the sixteenth NMOS transistor Tr16 provided in the first stage BST1. Then, the third voltage source VSS is supplied to the first node Q of the first stage BST1 through the turned-on sixteenth NMOS transistor Tr16. Accordingly, the first node Q of the first stage BST1 is discharged. Accordingly, the second, third, ninth, fourteenth, and seventeenth NMOS transistors Tr2, Tr3, Tr9, Tr14, and Tr17 connected to the first node Q of the first stage BST1 are turned on. Is off. Also, at this time, the first, fourth, fifth, tenth, and fifteenth NMOSs of the first stage BST1 supplied with the start pulse SP in the low state as the start pulse SP changes to low. Transistors Tr1, Tr4, Tr5, Tr10, and Tr15 are turned off.

Here, as the second, fourth, ninth, and tenth NMOS transistors Tr2, Tr4, Tr9, and Tr10 of the first stage BST1 are turned off, the second stage of the first stage BST1 is turned off. The node QB1 is charged with the first voltage source VDD1 applied through the seventh NMOS transistor Tr7. Therefore, the eighth and eighteenth NMOS transistors Tr8 and Tr18 having gate terminals connected to the second node QB1 of the first stage BST1 are turned on.

As the third and fifth NMOS transistors Tr3 and Tr5 of the first stage BST1 are turned off, the third node QB2 of the first stage BST1 maintains a discharge state. Accordingly, the thirteenth and nineteenth NMOS transistors Tr13 and Tr19 having gate terminals connected to the third node QB2 of the first stage BST1 maintain a turn-off state.

In this way, the first node Q and the third node QB2 of the first stage BST1 are discharged by the third scan pulse Vout3 from the third stage BST3, and the second node ( QB1) is charged. That is, the first stage BST1 is disabled in response to the third scan pulse Vout3 from the third stage BST3. The disabled first stage BST1 outputs the third voltage source VSS through the twelfth NMOS transistor Tr12 provided therein. Then, the third voltage source VSS is supplied to the first gate line.

In this manner, each stage BST1 to BSTn + 2 is enabled by a scan pulse output from the previous stage from itself. Then, each stage BST1 to BSTn + 2 is disabled by the scan pulse from the stage located next to it.

On the other hand, the first voltage source VDD1 is maintained at the negative polarity and the second voltage source VDD2 is maintained at the positive polarity in the second frame. As a result, when the stages BST1 to BSTn + 2 are disabled, the second node QB1 of each stage BST1 to BSTn + 2 is discharged and the third node QB2 is charged. Therefore, when each of the stages BST1 to BSTn + 2 is disabled, the third voltage source VSS is output through the nineteenth NMOS transistor Tr19 having a gate terminal connected to the third node QB2. As such, since the second and third nodes QB1 and QB2 are alternately charged / discharged for each frame, deterioration of the eighteenth and nineteenth NMOS transistors Tr18 and Tr19 included in the output unit 900b. Can be prevented.

Hereinafter, the shift register according to the second embodiment of the present invention will be described in detail.

11 is a diagram illustrating a shift register according to a second embodiment of the present invention.

As illustrated in FIG. 11, the shift register according to the second embodiment of the present invention includes n stages connected to each other and first and second dummy stages CSTn + 1 and CSTn + 2. . Here, all the stages CST1 to CSTn + 2 output one scan pulse Vout1 to Voutn + 2, and in this case, scan pulses are sequentially performed from the first stage CST1 to the second dummy stage CSTn + 2. (Vout1 to Voutn + 2) is output. In this case, the scan pulses Vout1 to Voutn output from the stages CST1 to CSTn except for the first and second dummy stages CSTn + 1 and CSTn + 2 are connected to the liquid crystal panel (not shown). The gate lines are sequentially supplied to sequentially scan the gate lines. Here, the shift register consisting of the stages CST1 to CSTn + 2 is preferably embedded on the liquid crystal panel.

On the other hand, the entire stages CST1 to CSTn of the shift registers configured as described above are the first to fourth voltage sources VDD, VSS, VDD3, and VDD4 and the first to fourth clock pulses CLK1 to cyclic with sequential phase differences. One clock pulse of CLK4) is applied. Here, the first voltage source VDD refers to a positive DC voltage source, and the second voltage source VSS refers to a negative voltage source. The third voltage source VDD3 and the fourth voltage source VDD4 are AC voltage sources having polarities inverted for each frame. In this case, the third voltage source VDD3 has an inverted phase with respect to the fourth voltage source VDD4. That is, the third voltage source VDD3 and the fourth voltage source VDD4 have different polarities within the same frame. Each of the first to fourth clock pulses CLK1 to CLK4 is repeatedly output with a predetermined period.

Here, the first stage CST1 located on the uppermost side of the stages CST1 to CSTn + 2, that is, the first stage that outputs the scan pulse to the first of the stages CST1 to CSTn + 2, The start pulse SP is supplied in addition to the first to fourth voltage sources VDD, VSS, VDD3, and VDD4 and one of the first to fourth clock pulses CLK1 to CLK4.

On the other hand, as described above, the first to fourth clock pulses CLK1 to CLK4 are delayed and outputted from each other. That is, the second clock pulse CLK2 is output after being phase-delayed than the first clock pulse CLK1, and the third clock pulse CLK3 is output by being phase-delayed than the second clock pulse CLK2. The fourth clock pulse CLK4 is output in phase delay than the third clock pulse CLK3 and the first clock pulse CLK1 is output in phase delay than the fourth clock pulse CLK4.

Meanwhile, the start pulse SP applied to the first stage CST1 among the stages CST1 to CSTn + 1 is output before the clock pulses CLK1 to CLK4. In addition, the start pulse SP is output only once in one frame. That is, after the start pulse SP is output first in every frame, the first to fourth clock pulses CLK1 to CLK4 are sequentially output. At this time, the first to fourth clock pulses CLK1 to CLK4 are sequentially output, and are also output while circulating. That is, after the first clock pulse CLK1 to the fourth clock pulse CLK4 are sequentially output, the first clock pulse CLK1 to the fourth clock pulse CLK4 are sequentially output. Therefore, the first clock pulse CLK1 is output in a period corresponding to the fourth clock pulse CLK4 and the second clock pulse CLK2. The fourth clock pulse CLK4 and the start pulse SP may be output in synchronization with each other. In this case, the fourth clock pulse CLK4 is first outputted among the first to fourth clock pulses CLK1 to CLK4.

Meanwhile, the shift register according to the present invention may use two or more clock pulses. That is, the shift register according to the present invention may use only the first and second clock pulses CLK1 and CLK2 among the first to fourth clock pulses CLK1 to CLK4, and the first to third clock pulses CLK1 to CLK4. You can also use only CLK3). In addition, the shift register according to the present invention may use four or more clock pulses sequentially output.

The operation of the shift register configured as described above will be described in detail as follows.

First, when the start pulse SP from the timing controller is input to the first stage CST1, the first stage CST1 is enabled in response to the start pulse SP. Subsequently, the enabled first stage CST1 receives the first clock pulse CLK1 from the timing controller and outputs a first scan pulse Vout1. The first stage CST1 receives the first gate line and the second stage CST2. To feed. Then, the second stage CST2 is enabled in response to the first scan pulse Vout1. Subsequently, the enabled second stage CST2 receives the second clock pulse CLK2 from the timing controller and outputs a second scan pulse Vout2. The second stage CST2 receives the second gate line and the third stage CST3. Supplies). Then, the third stage CST3 is enabled in response to the second scan pulse Vout2. Subsequently, the enabled third stage CST3 receives the third clock pulse CLK3 from the timing controller and outputs a third scan pulse Vout3. The third stage CST3 receives the third gate line and the fourth stage CST4. And the first stage CST1 together. Then, the fourth stage CST4 is enabled in response to the third scan pulse Vout3, and the first stage CST1 supplies a second voltage source VSS to the first gate line. Subsequently, the enabled fourth stage CST4 receives the fourth clock pulse CLK4 from the timing controller and outputs a fourth scan pulse Vout4, and the fourth gate line and the fifth stage, and Supply to the second stage CST2. Then, the fifth stage CST5 is enabled in response to the fourth scan pulse Vout3, and the second stage CST2 supplies a second voltage source VSS to the third gate line. Subsequently, the enabled fifth stage receives the first clock pulse CLK1 from the timing controller and outputs a fifth scan pulse, and the fifth gate line, the sixth stage, and the third stage CST3. ) Together. Then, the sixth stage is enabled in response to the fifth scan pulse, and the third stage CST3 supplies a second voltage source VSS to the third gate line. In this manner, the sixth to nth scan pulses Voutn are sequentially output to the sixth to nth stages CSTn, and they are sequentially supplied to the sixth to nth gate lines, respectively. In this case, the adjacent scan pulses have a pulse width section overlapping by a predetermined time. Here, the first dummy stage CSTn + 1 serves to supply the n + 1 scan pulse Voutn + 1 to the n-1th stage CSTn-1, and the second dummy stage CSTn + 2. 300h serves to supply the n + 2th scan pulse Voutn + 2 to the nth stage CSTn. That is, the n + 1 and n + 2 scan pulses Voutn + 1 and Voutn + 2 output from the first and second dummy stages CSTn + 1 and CSTn + 2 are not supplied to the gate line. Only the nth-1 and nth stages CSTn-1 and CSTn are dummy outputs which serve to output the second voltage source VSS.

In this manner, each stage CST1 to CSTn + 2 outputs scan pulses Vout1 to Voutn + 2, and supplies them sequentially to the corresponding gate lines, respectively, and at the next stage, as a start pulse SP. to provide. Each of the stages CST1 to CSTn + 2 supplies a second voltage source VSS to a corresponding gate line in response to a scan pulse output from a stage located next to the next stage.

Here, each stage of the shift register according to the second embodiment of the present invention will be described in more detail as follows.

FIG. 12 is a circuit diagram illustrating the third stage of FIG. 11.

Each stage of the shift register according to the second embodiment of the present invention also includes the node control unit 120a and the output unit 120b as described above.

The node controller 120a of the third stage CST3 includes first to twelfth NMOS transistors Tr1 to Tr12.

The first NMOS transistor Tr1 charges the first node Q to the first voltage source VDD in response to the scan pulse from the previous stage. That is, the first NMOS transistor Tr1 charges the first node Q to the first voltage source VDD in response to the second scan pulse Vout2 from the second stage CST2. To this end, the gate terminal of the first NMOS transistor Tr1 is connected to the second stage CST2, the source terminal is connected to a power line for transmitting the first voltage source VDD, and the drain terminal is connected to the first node. It is connected to (Q).

The second NMOS transistor Tr2 discharges the second node QB1 to the second voltage source VSS in response to the scan pulse from the previous stage. That is, the second NMOS transistor Tr2 discharges the second node QB1 to the second voltage source VSS in response to the second scan pulse Vout2 from the second stage CST2. To this end, the gate terminal of the second NMOS transistor Tr2 is connected to the second stage CST2, the source terminal is connected to the second node QB1, and the drain terminal transmits the second voltage source VSS. Is connected to the power supply line.

The third NMOS transistor Tr3 discharges the third node QB2 to the second voltage source VSS in response to the scan pulse from the previous stage. That is, the third NMOS transistor Tr3 discharges the third node QB2 to the second voltage source VSS in response to the second scan pulse Vout2 from the second stage CST2. To this end, the gate terminal of the third NMOS transistor Tr3 is connected to the second stage CST2, the source terminal is connected to the second node QB1, and the drain terminal transmits the second voltage source VSS. It is connected to the power line.

The fourth NMOS transistor Tr4 is turned on or turned off in response to the third voltage source VDD3, and charges the second node QB1 to the third voltage source VDD3 at turn-on. For this purpose, the gate terminal of the fourth NMOS transistor Tr4 is connected to a power line for transmitting the third voltage source VDD3, the source terminal is connected to a power line for transmitting the third voltage source VDD3, and the drain The terminal is connected to the second node QB1. The third voltage source VDD3 is an AC voltage having alternating positive and negative polarities every frame. That is, the third voltage source VDD3 has positive polarity in odd frames and negative polarity in even frames.

The fifth NMOS transistor Tr5 discharges the third node QB2 to the second voltage source VSS in response to the third voltage source VDD3. To this end, the gate terminal of the fifth NMOS transistor Tr5 is connected to a power line for transmitting the third voltage source VDD3, the source terminal is connected to a third node QB2, and the drain terminal is connected to the second node. It is connected to a power supply line that transmits a voltage source VSS.

The sixth NMOS transistor Tr6 is turned on or off in response to the fourth voltage source VDD4, and charges the third node QB2 to the fourth voltage source VDD4 when turned on. To this end, the gate terminal of the sixth NMOS transistor Tr6 is connected to a power line for transmitting the fourth voltage source VDD4, and the source terminal is connected to a power line for transmitting the fourth voltage source VDD4. The drain terminal is connected to the third node QB2. Here, the fourth voltage source VDD4 is an AC voltage having alternating positive and negative polarities every frame. In this case, the fourth voltage source VDD4 has an inverted phase with the third voltage source VDD3. That is, the third voltage source VDD3 has negative polarity in odd frames and positive polarity in even frames.

The seventh NMOS transistor Tr7 discharges the second node QB1 to the second voltage source VSS in response to the fourth voltage source VDD4. To this end, a gate terminal of the seventh NMOS transistor Tr7 is connected to a power line for transmitting the fourth voltage source VDD4, a source terminal is connected to the second node QB1, and a drain terminal is connected to the second terminal QB1. 2 is connected to the power supply line for transmitting the voltage source (VSS).

The eighth NMOS transistor Tr8 discharges the second node QB1 to the second voltage source VSS in response to the first voltage source VDD charged in the first node Q. To this end, the gate terminal of the eighth NMOS transistor Tr8 is connected to the first node Q, the source terminal is connected to the second node QB1, and the drain terminal is connected to the second voltage source VSS. It is connected to the power line to transmit.

The ninth NMOS transistor Tr9 discharges the third node QB2 to the second voltage source VSS in response to the first voltage source VDD charged in the first node Q. To this end, the gate terminal of the ninth NMOS transistor Tr9 is connected to the first node Q, the source terminal is connected to the third node QB2, and the drain terminal transmits the second voltage source VSS. Is connected to a power supply line.

The tenth NMOS transistor Tr10 discharges the first node Q to the second voltage source VSS in response to the third voltage source VDD3 charged in the second node QB1. To this end, a gate terminal of the tenth NMOS transistor Tr10 is connected to the second node QB1, a source terminal is connected to the first node Q, and a drain terminal of the second voltage source VSS is connected. It is connected to the transmitting power line.

The eleventh NMOS transistor Tr11 discharges the first node Q to the second voltage source VSS in response to the fourth voltage source VDD4 charged in the third node QB2. To this end, a gate terminal of the eleventh NMOS transistor Tr11 is connected to the third node QB2, a source terminal is connected to the first node Q, and a drain terminal of the second voltage source VSS is connected. It is connected to the transmitting power line.

The twelfth NMOS transistor Tr12 discharges the first node Q to the second voltage source VSS in response to the scan pulse from the next stage. That is, the twelfth NMOS transistor Tr12 discharges the first node Q to the second voltage source VSS in response to the fifth scan pulse Vout5 from the fifth stage. To this end, the gate terminal of the twelfth NMOS transistor Tr12 is connected to the fifth stage, the source terminal is connected to the first node Q, and the drain terminal is connected to a power line for transmitting the second voltage source VSS. Connected.

And. The output part 120b of the 3rd stage CST3 is comprised from the 13th-15th NMOS transistors Tr13-Tr15.

The thirteenth NMOS transistor Tr13 outputs a clock pulse as a scan pulse to the gate line in response to the first voltage source VDD charged in the first node Q. In addition, this scan pulse is supplied to both the front stage and the next stage. For this purpose, the gate terminal of the thirteenth NMOS transistor Tr13 is connected to the first node Q, the source terminal is connected to the clock line for transmitting the third clock pulse CLK3, and the drain terminal is connected to the third gate. A line, a gate terminal of the twelfth NMOS provided in the first stage CST1, and a gate terminal of the first through third NMOS transistors Tr1 through Tr3 provided in the fourth stage CST4.

The fourteenth NMOS transistor Tr14 supplies the second voltage source VSS to the gate line in response to the third voltage source VDD3 charged in the second node QB1. That is, the fourteenth NMOS transistor Tr14 supplies the second voltage source VSS to the third gate line in response to the third voltage source VDD3 charged in the second node QB1. To this end, the gate terminal of the fourteenth NMOS transistor Tr14 is connected to the second node QB1, the drain terminal is connected to a power line for transmitting the second voltage source VSS, and the source terminal is connected to the second gate line. And the gate terminals of the twelfth NMOS transistor Tr12 provided in the first stage CST1 and the gate terminals of the first through third NMOS transistors Tr1 through Tr3 provided in the fourth stage CST4.

The fifteenth NMOS transistor Tr15 supplies the second voltage source VSS to the gate line in response to the fourth voltage source VDD4 charged in the third node QB2. That is, the fifteenth NMOS transistor Tr15 supplies the second voltage source VSS to the third gate line in response to the fourth voltage source VDD4 charged in the third node QB2. To this end, the gate terminal of the fifteenth NMOS transistor Tr15 is connected to the second node QB1, the drain terminal is connected to a power line for transmitting the second voltage source VSS, and the source terminal is connected to the third gate line. The gate terminals of the twelfth NMOS provided in the first stage CST1 and the gate terminals of the first through third NMOS transistors Tr1 through Tr3 provided in the fourth stage CST4.

The first and second stages CST1 and CST2, the fourth to nth stages CST4 to CSTn, and the first and second dummy stages CSTn + 1 and CSTn + 2 are also described in the third stage CST3. Has the same configuration as

However, since there is no stage before the first stage CST1, the first to third NMOS transistors Tr1 to Tr3 included in the first stage CST1 may have the start pulse SP from the timing controller. Is supplied). That is, the first NMOS transistor Tr1 of the first stage CST1 receives the first node Q of the first stage CST1 in response to the start pulse SP from the timing controller. Charge with a voltage source VDD. The second NMOS transistor Tr2 discharges the second node QB1 of the first stage CST1 to the second voltage source VSS in response to the start pulse SP from the timing controller. . The third NMOS transistor Tr3 discharges the third node QB2 of the first stage CST1 to the second voltage source VSS in response to the start pulse SP from the timing controller. .

The stage is not present at the front ends of the first and second stages CST1 and CST2. Therefore, the first stage CST1 outputs the first scan pulse Vout1 and supplies it to the first gate line and the second stage CST2. Likewise, the second stage CST2 outputs the second scan pulse Vout2 and supplies it to the second gate line and the third stage CST3.

There is no stage next to the second dummy stage CSTn + 2. Therefore, the source terminal of the thirteenth NMOS transistor Tr13 of the second dummy stage CSTn + 2, the drain terminal of the fourteenth NMOS transistor Tr14, and the drain terminal of the fifteenth NMOS transistor Tr15 are n-th. It is connected to the gate terminal of the twelfth NMOS transistor Tr12 of the stage CSTn.

On the other hand, the first to 15 NMOS transistors (Tr1 to Tr15) it is preferable to use an amorphous TFT (Thin Film Transistor).

The operation of the shift register according to the embodiment of the present invention configured as described above is as follows.

FIG. 13 is a diagram illustrating first to third stages having the circuit configuration of FIG. 12.

Here, it is assumed that the third voltage source VDD3 is maintained at the positive voltage during the first frame, and the fourth voltage source VDD4 is maintained at the negative voltage, and the third voltage source VDD3 is negative during the second frame. It is assumed that the voltage is maintained at the polarity and the fourth voltage source VDD4 is maintained at the voltage of the positive polarity. That is, it is assumed that the third voltage source VDD3 is maintained as the positive polarity during the odd-numbered frame, and the fourth voltage source VDD4 is maintained as the negative polarity, and the third voltage source VDD3 is made into the negative polarity during the even-numbered frame. It is assumed that the fourth voltage source VDD4 remains positive.

First, the start pulse SP is applied to the gate terminal of the first NMOS transistor Tr1, the gate terminal of the second NMOS transistor Tr2, and the gate terminal of the third NMOS transistor Tr3, and thus, the first terminal. , Second, and third NMOS transistors Tr1, Tr2, Tr3 are turned on.

Then, the first voltage source VDD is supplied to the first node Q through the turned-on first NMOS transistor Tr1. In this case, as the first node Q is charged with the first voltage source VDD, the eighth, ninth, and thirteenth NMOS transistors Tr8 and Tr9 having gate terminals connected to the first node Q, respectively. , Tr13) is turned on at the same time. Here, the second voltage source VSS is supplied to the second node QB1 through the turned-on eighth NMOS transistor Tr8 and the second NMOS transistor Tr2. Accordingly, the second node QB1 is maintained in a discharged state, and the tenth and fourteenth NMOS transistors Tr10 and Tr14 having gate terminals connected to the second node QB1 are turned off.

The second voltage source VSS is supplied to the third node QB2 through the turned-on third and ninth NMOS transistors Tr3 and Tr9. In this case, as the third node QB2 is discharged to the second voltage source VSS, the eleventh and fifteen NMOS transistors Tr11 and Tr15 having gate terminals connected to the third node QB2 are turned on. Is off.

In addition, the fourth NMOS transistor Tr4 is turned on as the third voltage source VDD3 is applied to its gate terminal. Since the third voltage source VDD3 is always in a positive state during the first frame, the fourth NMOS transistor Tr4 is always turned on during the first frame. Here, the third voltage source VDD3 is supplied to the second node QB1 through the turned-on fourth NMOS transistor Tr4. As a result, the second voltage source VSS and the third voltage source VDD3 are simultaneously supplied to the second node QB1. However, since the number of transistors supplying the second voltage source VSS is greater than the number of transistors supplying the third voltage source VDD3, the second node QB1 is maintained as the second voltage source VSS. do. As a result, the second node QB1 maintains a discharge state. Accordingly, the tenth and fourteenth NMOS transistors Tr10 and Tr14 having gate terminals connected to the second node QB1 are turned off.

The third voltage source VDD3 is also supplied to the gate terminal of the fifth NMOS transistor Tr5. Accordingly, the fifth NMOS transistor Tr5 is also always turned on during the first frame. The second voltage source VSS is supplied to the third node QB2 through the turned-on fifth NMOS transistor Tr5. As a result, the third node QB2 is maintained in the discharge state by the third, fifth and ninth NMOS transistors Tr3, Tr5, and Tr9. Accordingly, the eleventh and fifteenth NMOS transistors Tr11 and Tr15 having a gate terminal connected to the third node QB2 are turned off.

The sixth NMOS transistor Tr6 is turned off by the fourth voltage source VDD4 applied to its gate terminal. In this case, since the fourth voltage source VDD4 is negatively maintained during the first frame, the sixth NMOS transistor Tr6 is always turned off during the first frame.

In addition, since the fourth voltage source VDD4 is also applied to the gate terminal of the seventh NMOS transistor Tr7, the seventh NMOS transistor Tr7 is always turned off during the first frame.

As such, the first node Q of the first stage CST1 is charged to the first voltage source VDD by the start pulse SP, and the second and third nodes QB1 and QB2 are secondly charged. By discharging to the voltage source VSS, the first stage CST1 is enabled.

In this state, when the first clock pulse CLK1 is supplied to the thirteenth NMOS transistor Tr13 of the first stage CST1, the thirteenth NMOS transistor Tr13 removes the first clock pulse CLK1. Outputs as one scan pulse (Vout1). In this case, since the first clock pulse CLK1 and the start pulse SP are superimposed and output, the first scan pulse Vout1 is superimposed on the start pulse SP and output.

The first scan pulse Vout1 is supplied to the first gate line and the second stage CST2. That is, the first scan pulse Vout1 from the first stage CST1 is supplied to the first, second, and third NMOS transistors Tr1, Tr2, and Tr3 of the second stage CST2. Accordingly, the first node Q of the second stage CST2 is charged, and the second and third nodes QB1 and QB2 are discharged. That is, the second stage CST2 is enabled by the first scan pulse Vout1. In other words, as the first stage CST1 is enabled by the start pulse SP, the second stage CST2 is enabled by the first scan pulse Vout1. In this state, when the second clock pulse CLK2 is supplied to the thirteenth NMOS transistor Tr13 of the second stage CST2, the thirteenth NMOS transistor Tr13 removes the second clock pulse CLK2. Outputs as 2 scan pulses (Vout2). In this case, since the second clock pulse CLK2 overlaps the first clock pulse CLK1, the second scan pulse Vout2 is output to overlap the first scan pulse Vout1.

The second scan pulse Vout2 is supplied to the second gate line and the third stage CST3. That is, the second scan pulse Vout2 from the second stage CST2 is supplied to the first, second, and third NMOS transistors Tr1, Tr2, and Tr3 of the third stage CST3. Accordingly, the first node Q of the third stage CST3 is charged, and the second and third nodes QB1 and QB2 are discharged. That is, the third stage CST3 is enabled by the second scan pulse Vout2. In other words, as the first stage CST1 is enabled by the start pulse SP, the third stage CST3 is enabled by the second scan pulse Vout2.

In this state, when the third clock pulse CLK3 is supplied to the thirteenth NMOS transistor Tr13 of the third stage CST3, the thirteenth NMOS transistor Tr13 removes the third clock pulse CLK3. Outputs as 3 scan pulses (Vout3). In this case, since the third clock pulse CLK3 overlaps the second clock pulse CLK2, the third scan pulse Vout3 is output to overlap the second scan pulse Vout2.

The third scan pulse Vout3 is supplied to the third gate line and the fourth stage CST4. That is, the third scan pulse Vout3 from the third stage CST3 is supplied to the first, second, and third NMOS transistors Tr1, Tr2, and Tr3 of the fourth stage CST4. Accordingly, the first node Q of the fourth stage CST4 is charged and the second and third nodes QB1 and QB2 are discharged. That is, the fourth stage CST4 is enabled by the third scan pulse Vout3. In other words, as the first stage CST1 is enabled by the start pulse SP, the fourth stage CST4 is enabled by the third scan pulse Vout3.

In this state, when the fourth clock pulse CLK4 is supplied to the thirteenth NMOS transistor Tr13 of the fourth stage CST4, the thirteenth NMOS transistor Tr13 removes the fourth clock pulse CLK4. Outputs as 4 scan pulses (Vout4). In this case, since the fourth clock pulse CLK4 overlaps the third clock pulse CLK3, the fourth scan pulse Vout4 is output to overlap the third scan pulse Vout3.

On the other hand, the third scan pulse Vout3 output from the third stage CST3 is also supplied to the twelfth NMOS transistor Tr12 of the first stage CST1. That is, the third scan pulse Vout3 is supplied to the gate terminal of the twelfth NMOS transistor Tr12 provided in the first stage CST1. Accordingly, the first stage CST1 is disabled.

In detail, the third scan pulse Vout3 turns on the twelfth NMOS transistor Tr12 included in the first stage CST1. Then, the second voltage source VSS is supplied to the first node Q of the first stage CST1 through the turned-on twelfth NMOS transistor Tr12. Accordingly, the first node Q of the first stage CST1 is discharged. Therefore, the eighth, ninth, and thirteenth NMOS transistors Tr8, Tr9, and Tr13 connected to the first node Q of the first stage CST1 are turned off. In addition, when the start pulse SP is changed to low, the first, second, and third NMOS transistors Tr1, Tr2, and the first stage CST1 of the first stage CST1 are supplied with the start pulse SP in the low state. Tr3) is turned off.

Here, since the second and eighth NMOS transistors Tr2 and Tr8 of the first stage CST1 are turned off, the second node QB1 of the first stage CST1 is the fourth NMOS transistor Tr4. Is charged to the first voltage source VDD. Accordingly, both the tenth and fourteenth NMOS transistors Tr10 and Tr14 having gate terminals connected to the second node QB1 of the first stage CST1 are turned on. At this time, the second voltage source VSS is supplied to the first gate line through the turned-on fourteenth NMOS transistor Tr14.

Meanwhile, the second voltage source VSS is supplied to the first node Q through the turned-on tenth NMOS transistor Tr10. As a result, the first node Q of the first stage CST1 is discharged by the tenth and twelfth NMOS transistors Tr10 and Tr12.

In this way, the first node Q and the third node QB2 of the first stage CST1 are discharged by the third scan pulse Vout3 from the third stage CST3, and the second node ( QB1) is charged. That is, the first stage CST1 is disabled in response to the third scan pulse Vout3 from the third stage CST3. The disabled first stage CST1 outputs the second voltage source VSS through the fourteenth NMOS transistor Tr14 provided therein. Then, the second voltage source VSS is supplied to the first gate line.

In this manner, each stage CST1 to CSTn + 2 is enabled by a scan pulse output from the previous stage from itself. Then, each stage CST1 to CSTn + 2 is disabled by the scan pulse from the stage located next to it.

On the other hand, the third voltage source VDD3 is maintained at the negative polarity and the fourth voltage source VDD4 is maintained at the positive polarity in the second frame. As a result, when the stages CST1 to CSTn + 2 are disabled, the second node QB1 of each stage CST1 to CSTn + 2 is discharged and the third node QB2 is charged. Therefore, when each of the stages CST1 to CSTn + 2 is disabled, the second voltage source VSS is output through the fifteenth NMOS transistor Tr15 having a gate terminal connected to the third node QB2. As described above, since the second and third nodes QB1 and QB2 are alternately charged / discharged for each frame, deterioration of the fourteenth and fifteenth NMOS transistors Tr15 included in the output unit 120b is prevented. can do.

On the other hand, the stage may have a circuit configuration as follows.

FIG. 14 is another circuit diagram of the third stage of FIG. 11.

The node control unit 140a of the third stage CST3 includes first to twentieth NMOS transistors Tr1 to Tr20.

The first NMOS transistor Tr1 charges the first node Q to the first voltage source VDD in response to the scan pulse from the previous stage. That is, the first NMOS transistor Tr1 charges the first node Q to the first voltage source VDD in response to the second scan pulse Vout2 from the second stage CST2. To this end, the gate terminal of the first NMOS transistor Tr1 is connected to the second stage CST2, and the source terminal is connected to a power line for transmitting the first voltage source VDD.

The second NMOS transistor Tr2 discharges the second node QB1 to the second voltage source VSS in response to the first voltage source VDD charged in the first node Q. To this end, a gate terminal of the second NMOS transistor Tr2 is connected to the first node Q, a source terminal is connected to the second node QB1, and a drain terminal is connected to the second voltage source VSS. It is connected to the power line to transmit.

The third NMOS transistor Tr3 discharges the third node QB2 to the second voltage source VSS in response to the first voltage source VDD charged in the first node Q. To this end, the gate terminal of the third NMOS transistor Tr3 is connected to the first node Q, the source terminal is connected to the third node QB2, and the drain terminal is connected to the second voltage source VSS. It is connected to the power line to transmit.

The fourth NMOS transistor Tr4 is turned on or off in response to the third voltage source VDD3 having a different polarity for each frame, and outputs the third voltage source VDD3 at turn-on. To this end, the gate terminal of the fourth NMOS transistor Tr4 is connected to a power line for transmitting the third voltage source VDD3, and the source terminal is connected to a power line for transmitting the third voltage source VDD3.

The fifth NMOS transistor Tr5 charges the second node QB1 to the third voltage source VDD3 in response to the third voltage source VDD3 output from the fourth NMOS transistor Tr4. To this end, a gate terminal of the fifth NMOS transistor Tr5 is connected to a drain terminal of the fourth NMOS transistor Tr4, a source terminal is connected to a power line that transmits the third voltage source VDD3, and a drain The terminal is connected to the second node QB1.

The sixth NMOS transistor Tr6 discharges the first node Q to the second voltage source VSS in response to the third voltage source VDD3 charged in the second node QB1. For this purpose, the gate terminal of the sixth NMOS transistor Tr6 is connected to the second node QB1, the source terminal is connected to the first node Q, and the drain terminal of the sixth NMOS transistor Tr6 is connected to the second voltage source VSS. It is connected to the transmitting power line.

The seventh NMOS transistor Tr7 discharges the third node QB2 to the second voltage source VSS in response to the third voltage source VDD3 charged in the second node QB1. To this end, a gate terminal of the seventh NMOS transistor Tr7 is connected to the second node QB1, a source terminal is connected to the third node QB2, and a drain terminal thereof is connected to the second voltage source VSS. It is connected to the power line to transmit.

The eighth NMOS transistor Tr8 supplies the second voltage source VSS to the gate terminal of the fifth NMOS transistor Tr5 in response to the first voltage source VDD charged in the first node Q. 5 Turn off the NMOS transistor Tr5. For this purpose, the gate terminal of the eighth NMOS transistor Tr8 is connected to the first node Q, the source terminal is connected to the gate terminal of the fifth NMOS transistor Tr5, and the drain terminal of the eighth NMOS transistor Tr8 is connected to the second terminal. It is connected to a power supply line that transmits a voltage source VSS.

The ninth NMOS transistor Tr9 turns on the fifth NMOS transistor Tr5 by supplying the second voltage source VSS to the gate terminal of the fifth NMOS transistor Tr5 in response to the scan pulse from the previous stage. -Turn it off. That is, the ninth NMOS transistor Tr9 supplies the second voltage source VSS to the gate terminal of the fifth NMOS transistor Tr5 in response to the second scan pulse Vout2 from the second stage CST2. The fifth NMOS transistor Tr5 is turned off by the supply. To this end, the gate terminal of the ninth NMOS transistor Tr9 is connected to the second stage CST2, the source terminal is connected to the gate terminal of the fifth NMOS transistor Tr5, and the drain terminal of the ninth NMOS transistor Tr9. It is connected to a power supply line that transmits a voltage source VSS.

The tenth NMOS transistor Tr10 turns on the fifth NMOS transistor Tr5 by supplying a second voltage source VSS to the gate terminal of the fifth NMOS transistor Tr5 in response to the scan pulse from the previous stage. -Turn it off. That is, the tenth NMOS transistor Tr10 applies the second voltage source VSS to the gate terminal of the fifth NMOS transistor Tr5 in response to the second scan pulse Vout2 from the second stage CST2. The fifth NMOS transistor Tr5 is turned off by the supply. To this end, the gate terminal of the tenth NMOS transistor Tr10 is connected to the second stage CST2, the source terminal is connected to the gate terminal of the fifth NMOS transistor Tr5, and the drain terminal of the second NMOS transistor Tr10 is connected to the second terminal CST2. It is connected to a power supply line that transmits a voltage source VSS.

The eleventh NMOS transistor Tr11 is turned on or turned off in response to the fourth voltage source VDD4 having a different polarity for each frame, and outputs the fourth voltage source VDD4 at turn-on. To this end, the gate terminal of the eleventh NMOS transistor Tr11 is connected to a power line for transmitting the fourth voltage source VDD4, and the source terminal is connected to a power line for transmitting the fourth voltage source VDD4. Here, the fourth voltage source VDD4 has the polarity reversed to the third voltage source VDD3 every frame.

The twelfth NMOS transistor Tr12 charges the third node QB2 to the fourth voltage source VDD4 in response to the fourth voltage source VDD4 output from the eleventh NMOS transistor Tr11. For this purpose, the gate terminal of the twelfth NMOS transistor Tr12 is connected to the drain terminal of the eleventh NMOS transistor Tr11, the source terminal is connected to a power line for transmitting the fourth voltage source VDD4, and the drain The terminal is connected to the third node QB2.

The thirteenth NMOS transistor Tr13 discharges the first node Q to the second voltage source VSS in response to the fourth voltage source VDD4 charged in the third node QB2. To this end, a gate terminal of the thirteenth NMOS transistor Tr13 is connected to the third node QB2, a source terminal is connected to the first node Q, and a drain terminal of the second voltage source VSS is connected. It is connected to the transmitting power line.

The fourteenth NMOS transistor Tr14 discharges the second node QB1 to the second voltage source VSS in response to the fourth voltage source VDD4 charged in the third node QB2. To this end, a gate terminal of the fourteenth NMOS transistor Tr14 is connected to the third node QB2, a source terminal is connected to the second node QB1, and a drain terminal thereof is connected to the second voltage source VSS. It is connected to the power line to transmit.

The fifteenth NMOS transistor Tr15 supplies the second voltage source VSS to the gate terminal of the twelfth NMOS transistor Tr12 in response to the first voltage source VDD charged in the first node Q. The twelfth NMOS transistor Tr12 is turned off. To this end, the gate terminal of the fifteenth NMOS transistor Tr15 is connected to the first node Q, the source terminal is connected to the gate terminal of the twelfth NMOS transistor Tr12, and the drain terminal of the fifteenth NMOS transistor Tr15. 2 is connected to the power supply line for transmitting the voltage source (VSS).

The sixteenth NMOS transistor Tr16 supplies the second voltage source VSS to the gate terminal of the twelfth NMOS transistor Tr12 in response to the scan pulse from the previous stage, thereby supplying the twelfth NMOS transistor Tr12. Turn off. That is, the sixteenth NMOS transistor Tr16 turns off the twelfth NMOS transistor Tr12 in response to the second scan pulse Vout2 from the second stage CST2. To this end, a gate terminal of the sixteenth NMOS transistor Tr16 is connected to the first stage CST1, a source terminal is connected to a gate terminal of the twelfth NMOS transistor Tr12, and a drain terminal of the second NMOS transistor Tr16 is connected to the second terminal. It is connected to a power supply line that transmits a voltage source VSS.

The seventeenth NMOS transistor Tr17 supplies the twelfth NMOS transistor Tr12 by supplying a second voltage source VSS to the gate terminal of the twelfth NMOS transistor Tr12 in response to a scan pulse from a previous stage. Turn off. That is, the seventeenth NMOS transistor Tr17 turns off the twelfth NMOS transistor Tr12 in response to the second scan pulse Vout2 from the second stage CST2. To this end, a gate terminal of the seventeenth NMOS transistor Tr17 is connected to the second stage CST2, a source terminal is connected to a gate terminal of the twelfth NMOS transistor Tr12, and a drain terminal of the seventh NMOS transistor Tr17 is connected to the second terminal CST2. It is connected to a power supply line that transmits a voltage source VSS.

The eighteenth NMOS transistor Tr18 discharges the second node QB1 to the second voltage source VSS in response to the scan pulse from the previous stage. That is, the eighteenth NMOS transistor Tr18 discharges the second node QB1 to the second voltage source VSS in response to the second scan pulse Vout2 from the second stage CST2. To this end, the gate terminal of the eighteenth NMOS transistor Tr18 is connected to the second stage CST2, the source terminal is connected to the second node QB1, and the drain terminal transmits the second voltage source VSS. Is connected to the power supply line.

The nineteenth NMOS transistor Tr19 discharges the third node QB2 to the second voltage source VSS in response to the scan pulse from the previous stage. That is, the nineteenth NMOS transistor Tr19 discharges the third node QB2 to the second voltage source VSS in response to the second scan pulse Vout2 from the second stage CST2. To this end, the gate terminal of the nineteenth NMOS transistor Tr19 is connected to the second stage CST2, the source terminal is connected to the third node QB2, and the drain terminal transmits the second voltage source VSS. Is connected to the power supply line.

The twentieth NMOS transistor Tr20 discharges the first node Q to the second voltage source VSS in response to the scan pulse from the next stage. That is, the gate terminal of the twentieth NMOS transistor Tr20 discharges the first node Q to the second voltage source VSS in response to the fifth scan pulse Vout5 from the fifth stage. To this end, a gate terminal of the twentieth NMOS transistor Tr20 is connected to the fifth stage, a source terminal is connected to the first node Q, and a drain terminal transmits the second voltage source VSS. It is connected to the power line.

The output unit 140b of the third stage CST3 includes the twenty-first to twenty-third NMOS transistors Tr21 to Tr23.

The twenty-first NMOS transistor Tr21 outputs the third clock pulse CLK3 as a scan pulse to the gate line in response to the first voltage source VDD charged in the first node Q. The third scan pulse Vout3 is supplied to both the front stage and the next stage. For this purpose, the gate terminal of the twenty-first NMOS transistor Tr21 is connected to the first node Q, the source terminal is connected to the clock line for transmitting the third clock pulse CLK3, and the drain terminal is connected to the third gate. Lines, gate terminals of the twentieth NMOS transistor Tr20 provided in the first stage CST1, and first, ninth, tenth, sixteenth, seventeenth, and eighteenth provided in the fourth stage CST4. And gate terminals of the nineteenth NMOS transistors Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19.

The twenty-second NMOS transistor Tr22 supplies the second voltage source VSS to the gate line in response to the third voltage source VDD3 charged in the second node QB1. That is, the fourteenth NMOS transistor Tr14 supplies the second voltage source VSS to the third gate line in response to the third voltage source VDD3 charged in the second node QB1. For this purpose, the gate terminal of the twenty-second NMOS transistor Tr22 is connected to the second node QB1, the drain terminal is connected to a power line for transmitting the second voltage source VSS, and the source terminal is connected to the third gate line. , Gate terminals of the twentieth NMOS transistor Tr20 provided in the first stage CST1, and first, ninth, tenth, sixteenth, seventeenth, and 18th provided in the fourth stage CST4. The gate terminals of the nineteenth NMOS transistors Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19 are connected.

The twenty-third NMOS transistor Tr23 supplies the second voltage source VSS to the gate line in response to the fourth voltage source VDD4 charged in the third node QB2. That is, the twenty-third NMOS transistor Tr23 supplies the second voltage source VSS to the third gate line in response to the fourth voltage source VDD4 charged in the third node QB2. For this purpose, the gate terminal of the twenty-third NMOS transistor Tr23 is connected to the second node QB1, the drain terminal is connected to a power line for transmitting the second voltage source VSS, and the source terminal is connected to the third gate line. Gate terminals of the 20th NMOS provided in the first stage CST1, and first, ninth, 10th, 16th, 17th, 18th, and 19th NMOS transistors provided in the fourth stage CST4. It is connected to the gate terminals of (Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19).

The first and second stages CST1 and CST2, the fourth to nth stages CST4 to CSTn, and the first and second dummy stages CSTn + 1 and CSTn + 2 are also identical to the second stage CST2 described above. Has a configuration.

However, since there is no stage before the first stage CST1, the first, ninth, tenth, sixteenth, seventeenth, eighteenth, and nineteenth stages provided in the first stage CST1 are provided. The NMOS transistors Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19 are supplied with a start pulse SP from the timing controller. That is, the first NMOS transistor Tr1 of the first stage CST1 charges the first node Q to the first voltage source VDD in response to the start pulse SP from the timing controller.

In addition, the ninth NMOS transistor Tr9 of the first stage CST1 removes the second node QB1 of the first stage CST1 in response to the start pulse SP from the timing controller. 2 discharge to a voltage source (VSS).

The tenth NMOS transistor Tr10 of the first stage CST1 supplies the second voltage source VSS to the gate terminal of the fourth NMOS transistor Tr4 in response to a start pulse from the timing controller. The fourth NMOS transistor Tr4 is turned off.

The 16th NMOS transistor Tr16 of the first stage CST1 supplies the second voltage source VSS to the gate terminal of the twelfth NMOS transistor Tr12 in response to a start pulse from the timing controller. As a result, the twelfth NMOS transistor Tr12 is turned off.

The 17th NMOS transistor Tr17 of the first stage CST1 supplies the second voltage source VSS to the gate terminal of the twelfth NMOS transistor Tr12 in response to a start pulse from the timing controller. As a result, the twelfth NMOS transistor Tr12 is turned off.

In addition, the eighteenth NMOS transistor Tr18 of the first stage CST1 discharges the second node QB1 to the second voltage source VSS in response to the start pulse SP from the timing controller.

In addition, the nineteenth NMOS transistor Tr19 of the first stage CST1 discharges the third node QB2 to the second voltage source VSS in response to the start pulse SP from the timing controller.

There is no stage at the front ends of the first and second stages CST1 and CST2. Therefore, the first stage CST1 outputs the first scan pulse Vout1 and supplies it to the first gate line and the second stage CST2. Similarly, the second stage CST2 outputs the second scan pulse Vout2 and supplies it to the second gate line and the third stage CST3.

There is no stage next to the second dummy stage CSTn + 2. Therefore, the source terminal of the twenty-first NMOS transistor Tr21 of the second dummy stage CSTn + 2, the drain terminal of the twenty-second NMOS transistor Tr22, and the drain terminal of the twenty-third NMOS transistor Tr23 are n-th. The gate terminal of the twentieth NMOS transistor Tr20 of the stage CSTn is connected.

On the other hand, the first to 23 NMOS transistor (Tr1 to Tr23) it is preferable to use an amorphous TFT (Thin Film Transistor).

The operation of the shift register according to the embodiment of the present invention configured as described above is as follows.

FIG. 15 is a diagram illustrating first to third stages having the circuit configuration of FIG. 14.

Here, it is assumed that the third voltage source VDD3 is maintained at the positive voltage during the first frame, and the fourth voltage source VDD4 is maintained at the negative voltage, and the third voltage source VDD3 is negative during the second frame. It is assumed that the voltage is maintained at the polarity and the fourth voltage source VDD4 is maintained at the voltage of the positive polarity. That is, it is assumed that the third voltage source VDD3 is maintained as a positive polarity and the fourth voltage source VDD4 is maintained as a negative polarity during an odd numbered frame, and the third voltage source VDD3 is a negative polarity during an even numbered frame. It is assumed that the fourth voltage source VDD4 remains positive.

First, the start pulse SP is a gate terminal of the first NMOS transistor Tr1, a gate terminal of the ninth NMOS transistor Tr9, a gate terminal of the tenth NMOS transistor Tr10, and a gate of the sixteenth NMOS transistor Tr16. A terminal, a gate terminal of the seventeenth NMOS transistor Tr17, a gate terminal of the eighteenth NMOS transistor Tr18, and a gate terminal of the nineteenth NMOS transistor Tr19 to be applied to the first, ninth, tenth, and tenth terminals. The 16th, 17th, 18th, and 19th NMOS transistors Tr19 are turned on.

Here, the first voltage source VDD is supplied to the first node Q through the turned-on first NMOS transistor Tr1. In this case, as the first node Q is charged with the first voltage source VDD, second, third, eighth, fifteenth, and twenty-first NMOSs having gate terminals connected to the first node Q, respectively. Transistors Tr2, Tr3, Tr8, Tr15, and Tr21 are turned on.

The second voltage source VSS is supplied to the second node QB1 through the turned-on second and eighth NMOS transistors Tr2 and Tr8. Accordingly, the second node QB1 is discharged, and the sixth, seventh, and twenty-second NMOS transistors Tr6, Tr7, and Tr22 having gate terminals connected to the second node QB1 are turned off. .

The second voltage source VSS is supplied to the third node QB2 through the turned-on third and nineteenth NMOS transistors Tr3 and Tr19. Accordingly, the third node QB2 is discharged, and the thirteenth, fourteenth, and twenty-third NMOS transistors Tr14 and Tr23 having gate terminals connected to the third node QB2 are turned off.

The second voltage source VSS is supplied to the gate terminal of the fifth NMOS transistor Tr5 through the turned-on eighth, ninth, and tenth NMOS transistors Tr8, Tr9, and Tr10. In addition, the third voltage source VDD3 is connected to the fifth NMOS transistor Tr5 through the fourth NMOS transistor Tr4 which is always turned on for one frame by the positive third voltage source VDD3. It is supplied to the gate terminal. Therefore, the second voltage source VSS and the third voltage source VDD3 are supplied to the gate terminal of the fifth NMOS transistor Tr5. In this case, the number of transistors for supplying the second voltage source VSS to the gate terminal of the fifth NMOS transistor Tr5 is the number of transistors for supplying the third voltage source VDD3 to the gate terminal of the fifth NMOS transistor Tr5. Since more, the second voltage source VSS is maintained at the gate terminal of the fifth NMOS transistor Tr5. Thus, the fifth NMOS transistor Tr5 is turned off.

The second voltage source VSS is supplied to the gate terminal of the twelfth NMOS transistor Tr12 through the turned on fifteenth, sixteenth, and seventeenth NMOS transistors Tr15, Tr16, and Tr17. Thus, the twelfth NMOS transistor Tr12 is turned off. On the other hand, the eleventh NMOS transistor Tr11 is always turned off for one frame by the negative voltage source VDD4.

As such, the first node Q of the first stage CST1 is charged with the first voltage source VDD, and the second and third nodes QB1 and QB2 are discharged to the second voltage source VSS. The first stage CST1 is enabled.

In this state, when the first clock pulse CLK1 is supplied to the twenty-first NMOS transistor Tr21 of the first stage CST1, the twenty-first NMOS transistor Tr21 removes the first clock pulse CLK1. Outputs as one scan pulse (Vout1). In this case, since the first clock pulse CLK1 and the start pulse SP are superimposed and output, the first scan pulse Vout1 is superimposed on the start pulse SP and output.

The first scan pulse Vout1 is supplied to the first gate line and the second stage CST2. That is, the first scan pulse Vout1 from the first stage CST1 is configured as the first, ninth, tenth, sixteenth, seventeenth, eighteenth, and nineteenth NMOS transistors of the second stage CST2. Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19). Accordingly, the first node Q of the second stage CST2 is charged, and the second and third nodes QB1 and QB2 are discharged. That is, the second stage CST2 is enabled by the first scan pulse Vout1. In other words, as the first stage CST1 is enabled by the start pulse SP, the second stage CST2 is enabled by the first scan pulse Vout1. In this state, when the second clock pulse CLK2 is supplied to the twenty-first NMOS transistor Tr21 of the second stage CST2, the twenty-first NMOS transistor Tr21 removes the second clock pulse CLK2. Outputs as 2 scan pulses (Vout2). In this case, since the second clock pulse CLK2 overlaps the first clock pulse CLK1, the second scan pulse Vout2 is output to overlap the first scan pulse Vout1.

The second scan pulse Vout2 is supplied to the second gate line and the third stage CST3. That is, the second scan pulse Vout2 from the second stage CST2 is the first, ninth, tenth, sixteenth, seventeenth, eighteenth, and nineteenth NMOS transistors of the third stage CST3. It is supplied to (Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, Tr19). Accordingly, the first node Q of the third stage CST3 is charged, and the second and third nodes QB1 and QB2 are discharged. That is, the third stage CST3 is enabled by the second scan pulse Vout2. In other words, as the first stage CST1 is enabled by the start pulse SP, the third stage CST3 is enabled by the second scan pulse Vout2.

In this state, when the third clock pulse CLK3 is supplied to the twenty-first NMOS transistor Tr21 of the third stage CST3, the twenty-first NMOS transistor Tr21 removes the third clock pulse CLK3. Outputs as 3 scan pulses (Vout3). In this case, since the third clock pulse CLK3 overlaps the second clock pulse CLK2, the third scan pulse Vout3 is output to overlap the second scan pulse Vout2.

The third scan pulse Vout3 is supplied to the third gate line and the fourth stage CST4. That is, the third scan pulse Vout3 from the third stage CST3 includes the first, ninth, tenth, sixteenth, seventeenth, eighteenth, and nineteenth NMOS transistors of the fourth stage CST4. Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19). Accordingly, the first node Q of the fourth stage CST4 is charged and the second and third nodes QB1 and QB2 are discharged. That is, the fourth stage CST4 is enabled by the third scan pulse Vout3. In other words, as the first stage CST1 is enabled by the start pulse SP, the fourth stage CST4 is enabled by the third scan pulse Vout3.

In this state, when the fourth clock pulse CLK4 is supplied to the twenty-first NMOS transistor Tr21 of the fourth stage CST4, the twenty-first NMOS transistor Tr21 removes the fourth clock pulse CLK4. Outputs as 4 scan pulses (Vout4). In this case, since the fourth clock pulse CLK4 overlaps the third clock pulse CLK3, the fourth scan pulse Vout4 is output to overlap the third scan pulse Vout3.

The third scan pulse Vout3 output from the third stage CST3 is also supplied to the twentieth NMOS transistor Tr20 of the first stage CST1. That is, the third scan pulse Vout3 is supplied to the gate terminal of the twentieth NMOS transistor Tr20 provided in the first stage CST1. Accordingly, the first stage CST1 is disabled.

Specifically, the third scan pulse Vout3 turns on the twentieth NMOS transistor Tr20 provided in the first stage CST1. Then, the second voltage source VSS is supplied to the first node Q of the first stage CST1 through the turned-on 20th NMOS transistor Tr20. Accordingly, the first node Q of the first stage CST1 is discharged. Accordingly, the second, third, eighth, fifteenth, and twenty-first NMOS transistors Tr2, Tr3, Tr8, Tr15, and Tr21 connected to the first node Q of the first stage CST1 are turned on. Is off. Also, at this time, the first, ninth, tenth, sixteenth, seventeenth, and the first stages of the first stage CST1 supplied with the start pulse SP in the low state as the start pulse SP changes to low. The 18th and 19th NMOS transistors Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19 are turned off.

As the ninth and tenth NMOS transistors Tr9 and Tr10 of the first stage CST1 are turned off, the second terminal is no longer provided to the gate terminal of the fifth NMOS transistor Tr5 of the first stage CST1. The voltage source VSS is not supplied. Instead, the third voltage source VDD3 is supplied to the gate terminal of the fifth NMOS transistor Tr5 of the first stage CST1 through the fourth NMOS transistor Tr4. As a result, the fifth NMOS transistor Tr5 is turned on by the third voltage source VDD3. The third voltage source VDD3 is supplied to the second node QB1 of the first stage CST1 through the turned-on fifth NMOS transistor Tr5. Accordingly, the sixth, seventh, and twenty-second nodes in which the second node QB1 of the first stage CST1 is charged and the gate terminal is connected to the second node QB1 of the first stage CST1 are charged. The NMOS transistors Tr6, Tr7, and Tr22 are turned on.

Meanwhile, the second voltage source VSS is supplied to the first node Q of the first stage CST1 through the turned-on sixth NMOS transistor Tr6. As a result, the discharge rate of the first node Q of the first stage CST1 is further increased. The second voltage source VSS is supplied to the third node QB2 of the first stage CST1 through the turned-on seventh NMOS transistor Tr7. Accordingly, the third node QB2 is discharged, and the thirteenth, fourteenth, and twenty-third NMOS transistors Tr13, Tr14, and Tr23 having gate terminals connected to the third node QB2 are turned off. .

In this way, the first node Q and the third node QB2 of the first stage CST1 are discharged by the third scan pulse Vout3 from the third stage CST3, and the second node ( QB1) is charged. That is, the first stage CST1 is disabled in response to the third scan pulse Vout3 from the third stage CST3. The disabled first stage CST1 outputs the second voltage source VSS through the twenty-second NMOS transistor Tr22 provided therein. Then, the second voltage source VSS is supplied to the first gate line.

In this manner, each stage CST1 to CSTn + 2 is enabled by a scan pulse output from the previous stage from itself. Then, each stage CST1 to CSTn + 2 is disabled by the scan pulse from the stage located next to it.

On the other hand, the third voltage source VDD3 is maintained at the negative polarity and the fourth voltage source VDD4 is maintained at the positive polarity in the second frame. As a result, when the stages CST1 to CSTn + 2 are disabled, the second node QB1 of each stage CST1 to CSTn + 2 is discharged and the third node QB2 is charged. Therefore, when each of the stages CST1 to CSTn + 2 is disabled, the second voltage source VSS is output through the twenty-third NMOS transistor Tr23 having a gate terminal connected to the third node QB2. As such, since the second and third nodes QB1 and QB2 are alternately charged / discharged for each frame, the 22nd and 23rd NMOS transistors Tr22 and Tr23 of the output unit 140b are deteriorated. Can be prevented.

Hereinafter, the shift register according to the third embodiment of the present invention will be described in detail.

16 is a diagram illustrating a shift register according to a third embodiment of the present invention.

As illustrated in FIG. 16, the shift register according to the third embodiment of the present invention includes n stages connected to each other and first and second dummy stages DSTn + 1 and DSTn + 2. . Here, each of the stages DST1 to DSTn + 2 outputs two scan pulses Vout1 to Voutn + 2. That is, each of the stages DST1 to DSTn + 2 simultaneously outputs two scan pulses in pairs, and each of the stages DST1 to DSTn + 2 outputs a pair of scan pulses in sequence. In this case, the scan pulses Vout1 to Voutn output from the stages DST1 to DSTn except for the first and second dummy stages DSTn + 1 and DSTn + 2 are connected to the liquid crystal panel (not shown). The gate lines are sequentially supplied to sequentially scan the gate lines. Here, the shift register consisting of the stages DST1 to DSTn + 2 is preferably embedded on the liquid crystal panel.

That is, first, the first stage DST1 simultaneously outputs two first scan pulses Vout1, and then the second stage DST2 simultaneously outputs two second scan pulses Vout2, and then, The third stage DST3 simultaneously outputs two third scan pulses Vout3, and, finally, the nth stage outputs two nth scan pulses Voutn simultaneously. Meanwhile, after the nth stage outputs two nth scan pulses Voutn at the same time, the first dummy stage outputs the n + 1 scan pulses Voutn + 1, wherein the first dummy stage ( The n + 1 th scan pulse Voutn + 1 output from the DSTn + 1 is not supplied to the gate line but is supplied to the n-1 th stage DSTn-1 and the second dummy stage DSTn + 2. After the first dummy stage outputs two n + 1 scan pulses Voutn simultaneously, the second dummy stage DSTn + 2 outputs the n + 2 scan pulses Voutn + 1. In this case, the n + 2th scan pulse Voutn + 1 output from the second dummy stage DSTn + 2 is not supplied to the gate line but is supplied only to the nth stage DSTn.

In addition, the scan pulses output from the stages DST1 to DSTn + 2 are output so as to overlap a predetermined section with each other. That is, one stage has two output terminals (hereinafter, referred to as first and second output terminals), and outputs two scan pulses simultaneously through the first and second output terminals. In other words, one stage outputs the scan pulse through the first output terminal and simultaneously outputs the scan pulse through the second output terminal. Therefore, two scan pulses are simultaneously output from each stage DST1 to DSTn + 2. At this time, the scan pulses output through the first output terminals of the stages DST1 to DSTn + 2 overlap each other with a predetermined width. Of course, the scan pulses output through the second output terminals of the stages DST1 to DSTn + 2 also overlap each other with a predetermined width. For example, the two first scan pulses Vout1 output from the first stage DST1 overlap a predetermined width with the two second scan pulses Vout2 output from the second stage DST2.

Here, each of the stages DST1 to DSTn + 2 supplies one of two scan pulses to its corresponding gate line, and supplies the other to the next stage and the front stage. For example, the third stage DST3 outputs two third scan pulses Vout3, supplies one third scan pulse Vout3 to the third gate line, and another third scan pulse Vout3. Vout3) is supplied to the fourth stage DST4 and the first stage DST1. The first and second dummy stages DSTn + 1 to DSTn + 2 may output two scan pulses or one scan pulse.

Meanwhile, the entire stages DST1 to DSTn + 2 of the shift registers configured as described above are the first to fourth voltage sources VDD, VSS, VDD3, and VDD4, and the first to fourth clock pulses having sequential phase differences with each other. One clock pulse of CLK1 to CLK4 is applied. Here, the first voltage source VDD refers to a positive DC voltage source, and the second voltage source VSS refers to a negative voltage source. The third voltage source and the fourth voltage source VDD3 and VDD4 are AC voltage sources having polarities inverted for each frame. In this case, the third voltage source VDD3 has an inverted phase with respect to the fourth voltage source VDD4. That is, the third voltage source and the fourth voltage source VDD3 and VDD4 have different polarities within the same frame. Each of the first to fourth clock pulses CLK1 to CLK4 is repeatedly output with a predetermined period.

On the other hand, as described above, the first to fourth clock pulses CLK1 to CLK4 are delayed and outputted from each other. That is, the second clock pulse CLK2 is output after being phase-delayed than the first clock pulse CLK1, and the third clock pulse CLK3 is output by being phase-delayed than the second clock pulse CLK2. The fourth clock pulse CLK4 is output in phase delay than the third clock pulse CLK3 and the first clock pulse CLK1 is output in phase delay than the fourth clock pulse CLK4. At this time, the first to fourth clock pulses CLK1 to CLK4 are sequentially output, and are also output while being circulated. That is, after the first clock pulse CLK1 to the fourth clock pulse CLK4 are sequentially output, the first clock pulse CLK1 to the fourth clock pulse CLK4 are sequentially output. Therefore, the first clock pulse CLK1 is output in a period corresponding to the fourth clock pulse CLK4 and the second clock pulse CLK2. The fourth clock pulse CLK4 and the start pulse SP may be output in synchronization with each other. In this case, the fourth clock pulse CLK4 is first outputted among the first to fourth clock pulses CLK1 to CLK4.

Meanwhile, the shift register according to the present invention may use two or more clock pulses. That is, the shift register according to the present invention may use only the first and second clock pulses CLK1 and CLK2 among the first to fourth clock pulses CLK1 to CLK4, and the first to third clock pulses CLK1 to CLK4. You can also use only CLK3). In addition, the shift register according to the present invention may use four or more clock pulses sequentially output.

On the other hand, each stage DST1 to DSTn + 2 includes a node controller for controlling charging and discharging of the first, second, and third nodes, and a charge / discharge state of the first, second, and third nodes. The first and second output units may be turned on to selectively output scan pulses or second voltage sources VSS, and supply them to the gate lines of the liquid crystal panel. Here, the first output unit of each stage DST1 to DSTn + 2 supplies the scan pulse or the second voltage source VSS to the next stage and the previous stage. The second output unit of each of the stages DST1 to DSTn + 2 supplies a scan pulse or a second voltage source VSS to its corresponding gate line.

Here, the first, second, and third nodes are selectively charged and discharged. Specifically, when the first node Q is in a charged state, both the second node and the third node maintain a discharged state. do.

When the first node is in a discharged state, either one of the second node and the third node maintains a charged state. That is, in the odd frame, the second node is charged when the first node is in the discharge state, the third node is discharged, and in the even frame, when the first node is in the discharge state, the second node is discharged. The node is discharged and the third node is charged. As such, when the first node is in a discharged state, the reason for applying (charge and discharge) voltage sources VDD3 and VDD4 having different polarities to each of the frames by the second node and the third node is as follows. This is to prevent deterioration of a switching device having a gate terminal connected to three nodes. The charging and discharging states of the first, second, and third nodes are controlled by a plurality of switching elements (not shown) provided in the node controller.

Here, the configuration of the stage included in the shift register according to the third embodiment of the present invention will be described in more detail.

FIG. 17 is a circuit diagram illustrating the third stage of FIG. 16.

The node control unit 170a of the third stage DST3 includes first to twentieth NMOS transistors Tr1 to Tr20.

The first NMOS transistor Tr1 charges the first node Q to the first voltage source VDD in response to the scan pulse from the previous stage. That is, the first NMOS transistor Tr1 charges the first node Q to the first voltage source VDD in response to the second scan pulse Vout2 from the second stage CST2. . To this end, the gate terminal of the first NMOS transistor Tr1 is connected to the second stage CST2, and the source terminal is connected to a power line for transmitting the first voltage source VDD.

The second NMOS transistor Tr2 discharges the second node QB1 to the second voltage source VSS in response to the first voltage source VDD charged in the first node Q. To this end, a gate terminal of the second NMOS transistor Tr2 is connected to the first node Q, a source terminal is connected to the second node QB1, and a drain terminal is connected to the second voltage source VSS. It is connected to the power line to transmit.

The third NMOS transistor Tr3 discharges the third node QB2 to the second voltage source VSS in response to the first voltage source VDD charged in the first node Q. To this end, the gate terminal of the third NMOS transistor Tr3 is connected to the first node Q, the source terminal is connected to the third node QB2, and the drain terminal is connected to the second voltage source VSS. It is connected to the power line to transmit.

The fourth NMOS transistor Tr4 is turned on or off in response to the third voltage source VDD3 having a different polarity for each frame, and outputs the third voltage source VDD3 at turn-on. To this end, the gate terminal of the fourth NMOS transistor Tr4 is connected to a power line for transmitting the third voltage source VDD3, and the source terminal is connected to a power line for transmitting the third voltage source VDD3.

The fifth NMOS transistor Tr5 charges the second node QB1 to the third voltage source VDD3 in response to the third voltage source VDD3 output from the fourth NMOS transistor Tr4. To this end, a gate terminal of the fifth NMOS transistor Tr5 is connected to a drain terminal of the fourth NMOS transistor Tr4, a source terminal is connected to a power line that transmits the third voltage source VDD3, and a drain The terminal is connected to the second node QB1.

The sixth NMOS transistor Tr6 discharges the first node Q to the second voltage source VSS in response to the third voltage source VDD3 charged in the second node QB1. For this purpose, the gate terminal of the sixth NMOS transistor Tr6 is connected to the second node QB1, the source terminal is connected to the first node Q, and the drain terminal of the sixth NMOS transistor Tr6 is connected to the second voltage source VSS. It is connected to the transmitting power line.

The seventh NMOS transistor Tr7 discharges the third node QB2 to the second voltage source VSS in response to the third voltage source VDD3 charged in the second node QB1. To this end, a gate terminal of the seventh NMOS transistor Tr7 is connected to the second node QB1, a source terminal is connected to the third node QB2, and a drain terminal thereof is connected to the second voltage source VSS. It is connected to the power line to transmit.

The eighth NMOS transistor Tr8 supplies the second voltage source VSS to the gate terminal of the fifth NMOS transistor Tr5 in response to the first voltage source VDD charged in the first node Q. 5 Turn off the NMOS transistor Tr5. For this purpose, the gate terminal of the eighth NMOS transistor Tr8 is connected to the first node Q, the source terminal is connected to the gate terminal of the fifth NMOS transistor Tr5, and the drain terminal of the eighth NMOS transistor Tr8 is connected to the second terminal. It is connected to a power supply line that transmits a voltage source VSS.

The ninth NMOS transistor Tr9 turns on the fifth NMOS transistor Tr5 by supplying the second voltage source VSS to the gate terminal of the fifth NMOS transistor Tr5 in response to the scan pulse from the previous stage. -Turn it off. That is, the ninth NMOS transistor Tr9 supplies the second voltage source VSS to the gate terminal of the fifth NMOS transistor Tr5 in response to the second scan pulse Vout2 from the second stage CST2. The fifth NMOS transistor Tr5 is turned off by the supply. To this end, the gate terminal of the ninth NMOS transistor Tr9 is connected to the second stage CST2, the source terminal is connected to the gate terminal of the fifth NMOS transistor Tr5, and the drain terminal of the ninth NMOS transistor Tr9. It is connected to a power supply line that transmits a voltage source VSS.

The tenth NMOS transistor Tr10 turns on the fifth NMOS transistor Tr5 by supplying a second voltage source VSS to the gate terminal of the fifth NMOS transistor Tr5 in response to the scan pulse from the previous stage. -Turn it off. That is, the tenth NMOS transistor Tr10 applies the second voltage source VSS to the gate terminal of the fifth NMOS transistor Tr5 in response to the second scan pulse Vout2 from the second stage CST2. The fifth NMOS transistor Tr5 is turned off by the supply. To this end, the gate terminal of the tenth NMOS transistor Tr10 is connected to the second stage CST2, the source terminal is connected to the gate terminal of the fifth NMOS transistor Tr5, and the drain terminal of the second NMOS transistor Tr10 is connected to the second terminal CST2. It is connected to a power supply line that transmits a voltage source VSS.

The eleventh NMOS transistor Tr11 is turned on or turned off in response to a fourth voltage source VDD4 having a different polarity for each frame, and outputs the fourth voltage source VDD4 at turn-on. To this end, the gate terminal of the eleventh NMOS transistor Tr11 is connected to a power line for transmitting the fourth voltage source VDD4, and the source terminal is connected to a power line for transmitting the fourth voltage source VDD4. Here, the fourth voltage source VDD4 has the polarity inverted by the third voltage source VDD3 every frame.

The twelfth NMOS transistor Tr12 charges the third node QB2 to the fourth voltage source VDD4 in response to the fourth voltage source VDD4 output from the eleventh NMOS transistor Tr11. For this purpose, the gate terminal of the twelfth NMOS transistor Tr12 is connected to the drain terminal of the eleventh NMOS transistor Tr11, the source terminal is connected to a power line for transmitting the fourth voltage source VDD4, and the drain The terminal is connected to the third node QB2.

The thirteenth NMOS transistor Tr13 discharges the first node Q to the second voltage source VSS in response to the fourth voltage source VDD4 charged in the third node QB2. To this end, a gate terminal of the thirteenth NMOS transistor Tr13 is connected to the third node QB2, a source terminal is connected to the first node Q, and a drain terminal of the second voltage source VSS is connected. It is connected to the transmitting power line.

The fourteenth NMOS transistor Tr14 discharges the second node QB1 to the second voltage source VSS in response to the fourth voltage source VDD4 charged in the third node QB2. To this end, a gate terminal of the fourteenth NMOS transistor Tr14 is connected to the third node QB2, a source terminal is connected to the second node QB1, and a drain terminal thereof is connected to the second voltage source VSS. Is connected to the power supply line.

The fifteenth NMOS transistor Tr15 supplies the second voltage source VSS to the gate terminal of the twelfth NMOS transistor Tr12 in response to the first voltage source VDD charged in the first node Q. The twelfth NMOS transistor Tr12 is turned off. To this end, the gate terminal of the fifteenth NMOS transistor Tr15 is connected to the first node Q, the source terminal is connected to the gate terminal of the twelfth NMOS transistor Tr12, and the drain terminal of the fifteenth NMOS transistor Tr15. It is connected to a power supply line that transmits a voltage source VSS.

The sixteenth NMOS transistor Tr16 supplies the second voltage source VSS to the gate terminal of the twelfth NMOS transistor Tr12 in response to the scan pulse from the previous stage, thereby supplying the twelfth NMOS transistor Tr12. Turn off. That is, the sixteenth NMOS transistor Tr16 turns off the twelfth NMOS transistor Tr12 in response to the second scan pulse Vout2 from the second stage CST2. To this end, a gate terminal of the sixteenth NMOS transistor Tr16 is connected to the first stage CST1, a source terminal is connected to a gate terminal of the twelfth NMOS transistor Tr12, and a drain terminal of the second NMOS transistor Tr16 is connected to the second terminal. It is connected to a power supply line that transmits a voltage source VSS.

The seventeenth NMOS transistor Tr17 supplies the twelfth NMOS transistor Tr12 by supplying a second voltage source VSS to the gate terminal of the twelfth NMOS transistor Tr12 in response to a scan pulse from a previous stage. Turn off. That is, the seventeenth NMOS transistor Tr17 turns off the twelfth NMOS transistor Tr12 in response to the second scan pulse Vout2 from the second stage CST2. To this end, a gate terminal of the seventeenth NMOS transistor Tr17 is connected to the second stage CST2, a source terminal is connected to a gate terminal of the twelfth NMOS transistor Tr12, and a drain terminal of the seventh NMOS transistor Tr17 is connected to the second terminal CST2. It is connected to a power supply line that transmits a voltage source VSS.

The eighteenth NMOS transistor Tr18 discharges the second node QB1 to the second voltage source VSS in response to the scan pulse from the previous stage. That is, the eighteenth NMOS transistor Tr18 discharges the second node QB1 to the second voltage source VSS in response to the second scan pulse Vout2 from the second stage CST2. To this end, the gate terminal of the eighteenth NMOS transistor Tr18 is connected to the second stage CST2, the source terminal is connected to the second node QB1, and the drain terminal transmits the second voltage source VSS. Is connected to the power supply line.

The nineteenth NMOS transistor Tr19 discharges the third node QB2 to the second voltage source VSS in response to the scan pulse from the previous stage. That is, the nineteenth NMOS transistor Tr19 discharges the third node QB2 to the second voltage source VSS in response to the second scan pulse Vout2 from the second stage CST2. To this end, the gate terminal of the nineteenth NMOS transistor Tr19 is connected to the second stage CST2, the source terminal is connected to the third node QB2, and the drain terminal transmits the second voltage source VSS. Is connected to the power supply line.

The twentieth NMOS transistor Tr20 discharges the first node Q to the second voltage source VSS in response to the scan pulse from the next stage. That is, the gate terminal of the twentieth NMOS transistor Tr20 discharges the first node Q to the second voltage source VSS in response to the fifth scan pulse Vout5 from the fifth stage. To this end, a gate terminal of the twentieth NMOS transistor Tr20 is connected to the fifth stage, a source terminal is connected to the first node Q, and a drain terminal transmits the second voltage source VSS. It is connected to the power line.

The first output unit 170b of the third stage DST3 includes the twenty-first to twenty-third NMOS transistors Tr21 to Tr23.

The twenty-first NMOS transistor Tr21 outputs a clock pulse as a scan pulse in response to the first voltage source VDD charged in the first node Q. Then, this scan pulse is supplied to the front stage and the next stage. To this end, the gate terminal of the twenty-first NMOS transistor Tr21 is connected to the first node Q, the source terminal is connected to the clock line for transmitting the third clock pulse CLK3, and the drain terminal is connected to the first stage. Gate terminals of the twentieth NMOS transistor Tr20 provided in the DST1, and the first, ninth, tenth, sixteenth, seventeenth, and nineteenth NMOS transistors provided in the fourth stage DST4. It is connected to the gate terminals of (Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19).

The 22nd NMOS transistor Tr22 outputs the second voltage source VSS in response to the third voltage source VDD3 charged in the second node QB1. Then, the second voltage source VSS is supplied to the front stage and the next stage. To this end, the gate terminal of the twenty-second NMOS transistor Tr22 is connected to the second node QB1, the drain terminal is connected to a power line for transmitting the second voltage source VSS, and the source terminal is connected to the first stage ( The gate terminal of the twentieth NMOS transistor Tr20 provided in the DST1, and the first, ninth, tenth, sixteenth, seventeenth, eighteenth, and nineteenth NMOS transistors provided in the fourth stage DST4. It is connected to the gate terminals of Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19.

The twenty-third NMOS transistor Tr23 outputs the second voltage source VSS in response to the fourth voltage source VDD4 charged in the third node QB2. Then, the second voltage source VSS is supplied to the front stage and the next stage. To this end, the gate terminal of the twenty-third NMOS transistor Tr23 is connected to the second node QB1, the drain terminal is connected to a power line for transmitting the second voltage source VSS, and the source terminal is connected to the first stage ( The gate terminal of the twentieth NMOS transistor Tr20 provided in the DST1, and the first, ninth, tenth, sixteenth, seventeenth, eighteenth, and nineteenth NMOS transistors provided in the fourth stage DST4. It is connected to the gate terminals of Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19.

The second output unit 170c of the third stage DST3 is composed of the 24th to 26th NMOS transistors Tr24 to Tr26.

The 24 th NMOS transistor Tr24 outputs a clock pulse as a scan pulse in response to the first voltage source VDD charged in the first node Q. Then, this scan pulse is supplied to the front stage and the next stage. To this end, the gate terminal of the 24 th NMOS transistor Tr24 is connected to the first node Q, the source terminal is connected to the clock line for transmitting the third clock pulse CLK3, and the drain terminal is connected to the first stage. Gate terminals of the twentieth NMOS transistor Tr20 provided in the DST1, and the first, ninth, tenth, sixteenth, seventeenth, and nineteenth NMOS transistors provided in the fourth stage DST4. It is connected to the gate terminals of (Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19).

The 25 th NMOS transistor Tr22 outputs the second voltage source VSS in response to the third voltage source VDD3 charged in the second node QB1. Then, the second voltage source VSS is supplied to the front stage and the next stage. For this purpose, the gate terminal of the 25 th NMOS transistor Tr25 is connected to the second node QB1, the drain terminal is connected to a power line for transmitting the second voltage source VSS, and the source terminal is connected to the first stage ( The gate terminal of the twentieth NMOS transistor Tr20 provided in the DST1, and the first, ninth, tenth, sixteenth, seventeenth, eighteenth, and nineteenth NMOS transistors provided in the fourth stage DST4. It is connected to the gate terminals of Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19.

The 26th NMOS transistor Tr26 outputs the second voltage source VSS in response to the fourth voltage source VDD4 charged in the third node QB2. Then, the second voltage source VSS is supplied to the front stage and the next stage. For this purpose, the gate terminal of the 26 th NMOS transistor Tr26 is connected to the second node QB1, the drain terminal is connected to a power line for transmitting the second voltage source VSS, and the source terminal is connected to the first stage ( The gate terminal of the twentieth NMOS transistor Tr20 provided in the DST1, and the first, ninth, tenth, sixteenth, seventeenth, eighteenth, and nineteenth NMOS transistors provided in the fourth stage DST4. It is connected to the gate terminals of Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19.

The first and second stages DST1 and DST2, the fourth to nth stages DST4 to DSTn, and the first and second dummy stages DSTn + 1 and DSTn + 2 also have the above-described second stage DST2. Have the same configuration.

However, since there is no stage before the first stage DST1, the first, ninth, tenth, sixteenth, seventeenth, eighteenth, and nineteenth stages provided in the first stage DST1 are provided. The NMOS transistors Tr1, Tr9, Tr10, Tr16, Tr17, Tr18, and Tr19 are supplied with a start pulse SP from the timing controller. That is, the first NMOS transistor Tr1 of the first stage DST1 charges the first node Q to the first voltage source VDD in response to the start pulse SP from the timing controller.

In addition, the ninth NMOS transistor Tr9 of the first stage DST1 receives the second node QB1 of the first stage DST1 in response to the start pulse SP from the timing controller. Discharge to voltage source VSS.

The tenth NMOS transistor Tr10 of the first stage DST1 supplies the second voltage source VSS to the gate terminal of the fourth NMOS transistor Tr4 in response to the start pulse from the timing controller. The fourth NMOS transistor Tr4 is turned off.

The 16th NMOS transistor Tr16 of the first stage DST1 supplies the second voltage source VSS to the gate terminal of the twelfth NMOS transistor Tr12 in response to a start pulse from the timing controller. As a result, the twelfth NMOS transistor Tr12 is turned off.

The 17th NMOS transistor Tr17 of the first stage DST1 supplies the second voltage source VSS to the gate terminal of the twelfth NMOS transistor Tr12 in response to a start pulse from the timing controller. As a result, the twelfth NMOS transistor Tr12 is turned off.

The eighteenth NMOS transistor Tr18 of the first stage DST1 discharges the second node QB1 to the second voltage source VSS in response to the start pulse SP from the timing controller.

In addition, the nineteenth NMOS transistor Tr19 of the first stage DST1 discharges the third node QB2 to the second voltage source VSS in response to the start pulse SP from the timing controller.

There is no stage at the front ends of the first and second stages DST1 and DST2. Therefore, the first stage DST1 outputs the first scan pulse Vout1 and supplies it to the first gate line and the second stage DST2. Similarly, the second stage DST2 outputs the second scan pulse Vout2 and supplies it to the second gate line and the third stage DST3.

There is no stage next to the second dummy stage DSTn + 2. Therefore, the source terminal of the twenty-first NMOS transistor Tr21 of the second dummy stage DSTn + 2, the drain terminal of the twenty-second NMOS transistor Tr22, and the drain terminal of the twenty-third NMOS transistor Tr23 are n-th. It is connected to the gate terminal of the twentieth NMOS transistor Tr20 of the stage DSTn.

On the other hand, the first to 26 NMOS transistors (Tr1 to Tr26) it is preferable to use an amorphous TFT (Thin Film Transistor).

The operation of the shift register according to the third embodiment of the present invention configured as described above will be described in detail as follows.

18A and 18B show first to third stages having the circuit configuration of FIG.

The operation of the shift register according to the second embodiment of the present invention is the same as that of the circuit shown in Figs. 14, 15A, and 15B in the above-described first embodiment. Only each stage GST1 to GSTn + 1 of the shift register according to the second embodiment outputs two scan pulses. One scan pulse is supplied to the next stage and the previous stage, and the other is supplied to the corresponding gate line.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

The shift register according to the present invention as described above has the following effects.

The shift register of the liquid crystal display according to the present invention sequentially outputs a plurality of scan pulses, and increases and outputs the pulse widths of the scan pulses so that the pulse widths between the scan pulses output at adjacent times overlap each other for a predetermined period. . Therefore, the effective charging time of each scan pulse can be increased. If the effective charge time of each scan pulse is increased as described above, even if distortion occurs in the scan pulse due to the resistance and capacitance components of the gate line, sufficient effective charge time is applied to normally apply the data voltage to the pixel electrode. can do.

Claims (45)

In response to clock pulses from the timing controller, a shift including a plurality of stages sequentially outputting a plurality of scan pulses so that a predetermined section of their pulse widths overlap each other, and sequentially supplying them to the gate lines of the liquid crystal panel. In the register, Each stage said, A first switching element for charging a first node with the scan pulse in response to a start pulse or a scan pulse from a previous stage; A second switching element discharging a second node to a first voltage source in response to a scan pulse charged in the first node; A third switching device discharging a third node to a first voltage source in response to a scan pulse charged in the first node; A fourth switching element that is turned on or off in response to a second voltage source having a different polarity for each frame, and charges a second node with the second voltage source when turned on; A fifth switching element configured to discharge the first node to the first voltage source in response to the second voltage source charged in the second node; A sixth switching element which is turned on or off in response to the second voltage source and discharges the third node to the second voltage source when turned on; A seventh switching element having a different polarity for each frame and being turned on or off in response to a third voltage source having an inverted polarity with respect to the second voltage source, wherein the seventh switching element charges a third node with the third voltage source during turn-on; An eighth switching device discharging the first node to the first voltage source in response to the third voltage source charged in the third node; A ninth switching element that is turned on or off in response to the third voltage source and discharges a second node to the first voltage source when turned on; A tenth switching element for discharging the first node to the first voltage source in response to the scan pulse from the next stage; An eleventh switching device configured to output a scan pulse in response to the scan pulse charged in the first node, and supply the scan pulse to the gate line, the next stage, and the previous stage; A twelfth switching element configured to supply a first voltage source to the gate line in response to the second voltage source charged in the second node; And, And a thirteenth switching element for supplying the first voltage source to the gate line in response to the third voltage source charged to the third node. The method of claim 1, And a pulse width between clock pulses output from the timing controller is overlapped with each other by a predetermined portion. The method of claim 1, And a pulse width section overlapping the clock pulses and a pulse width section overlapping the scan pulses have the same width. The method of claim 1, A first dummy stage for outputting a scan pulse in response to a scan pulse from a stage of the last stage of the stages, and providing this as an input to a stage of the last stage, and in response to a scan pulse from the first dummy stage And a second dummy stage which outputs a scan pulse and provides it as an input to the stage of the last stage. The method of claim 1, And the first voltage is a negative DC voltage, and the second voltage is a positive DC voltage. The method of claim 1, Each of the clock pulses is repeatedly output with a predetermined period, and each of the clock pulses are sequentially output to each other. The method of claim 1, And the start pulse is supplied to a first stage which outputs a scan pulse first of the stages. The method of claim 1, And the first to thirteenth switching elements are amorphous thin film transistors (TFTs). The method of claim 1, And the stages are built in the liquid crystal panel. In response to clock pulses from the timing controller, a shift including a plurality of stages sequentially outputting a plurality of scan pulses so that a predetermined section of their pulse widths overlap each other, and sequentially supplying them to the gate lines of the liquid crystal panel. In the register, Each stage said, A first switching element for charging a first node with the scan pulse in response to a start pulse or a scan pulse from a previous stage; A second switching element for discharging the second node to the first voltage source in response to the scan pulse charged in the first node; A third switching element for discharging the third node to the first voltage source in response to the scan pulse charged in the first node; A fourth switching element for discharging the second node to the first voltage source in response to the start pulse or the scan pulse from the previous stage; A fifth switching element for discharging the third node to the first voltage source in response to the start pulse or the scan pulse from the previous stage; A sixth switching element turned on or off in response to a second voltage source having a different polarity for each frame and outputting the second voltage source when turned on; A seventh switching device configured to charge a second node with a second voltage source in response to the second voltage source output from the sixth switching device; An eighth switching element for discharging the first node to the first voltage source in response to the second voltage source charged to the second node; A ninth switching element which turns off the seventh switching element by supplying a first voltage source to the gate terminal of the seventh switching element in response to the scan pulse charged in the first node; A tenth switching element for turning off the seventh switching element by supplying a first voltage source to the gate terminal of the seventh switching element in response to a start pulse or a scan pulse from a previous stage; An eleventh switching element having a different polarity for each frame and being turned on or off in response to a third voltage source having a polarity inverted to the second voltage source, and outputting the third voltage source when turned on; A twelfth switching device configured to charge a third node with the third voltage source in response to a third voltage source output from the eleventh switching device; A thirteenth switching element discharging the first node to the first voltage source in response to the third voltage source charged to the third node; A fourteenth switching element turning off the twelfth switching element by supplying a first voltage source to the gate terminal of the twelfth switching element in response to the scan pulse charged in the first node; A fifteenth switching element that turns off the twelfth switching element by supplying a first voltage source to the gate terminal of the twelfth switching element in response to a start pulse or a scan pulse from a previous stage;  A sixteenth switching element for discharging the first node to the first voltage source in response to the scan pulse from the next stage; A seventeenth switching element outputting the scan pulse in response to the scan pulse charged in the first node and supplying the scan pulse to the gate line, the next stage, and the previous stage; An eighteenth switching element configured to supply a first voltage source to the gate line in response to the second voltage source charged in the second node; And, And a nineteenth switching element for supplying the first voltage source to the gate line in response to the third voltage source charged to the third node. The method of claim 10, And a pulse width between clock pulses output from the timing controller is overlapped with each other by a predetermined portion. The method of claim 10, And a pulse width section overlapping the clock pulses and a pulse width section overlapping the scan pulses have the same width. The method of claim 10, A first dummy stage for outputting a scan pulse in response to a scan pulse from a stage of the last stage of the stages, and providing this as an input to a stage of the last stage, and in response to a scan pulse from the first dummy stage And a second dummy stage which outputs a scan pulse and provides it as an input to the stage of the last stage. The method of claim 10, And the first voltage is a negative DC voltage, and the second voltage is a positive DC voltage. The method of claim 10, Each of the clock pulses is repeatedly output with a predetermined period, and each of the clock pulses are sequentially output to each other. The method of claim 10, And the start pulse is supplied to a first stage which outputs a scan pulse first of the stages. The method of claim 10, The first to nineteenth switching element is a shift resistor, characterized in that the amorphous TFT (Thin Film Transistor). The method of claim 10, And the stages are built in the liquid crystal panel. In response to clock pulses from the timing controller, a shift including a plurality of stages sequentially outputting a plurality of scan pulses so that a predetermined section of their pulse widths overlap each other, and sequentially supplying them to the gate lines of the liquid crystal panel. In the register, Each stage said, A first switching element for charging the first node with a first voltage source in response to a start pulse or a scan pulse from a previous stage; A second switching element for discharging a second node to a second voltage source in response to a start pulse or a scan pulse from a previous stage; A third switching element for discharging the third node to the second voltage source in response to the start pulse or the scan pulse from the previous stage; A fourth switching element which is turned on or turned off in response to a third voltage source having a different polarity for each frame, and charges the second node with a third voltage source at turn-on; A fifth switching element turned on or off in response to the third voltage source and discharging the third node to the second voltage source at turn-on; A sixth switching element that is turned on or off in response to a fourth voltage source and charges a third node with the fourth voltage source when turned on; A seventh switching element turned on or off in response to the fourth voltage source and discharging the second node to the second voltage source; An eighth switching element for discharging the second node to the second voltage source in response to the first voltage source charged to the first node; A ninth switching element configured to discharge the third node to the second voltage source in response to the first voltage source charged in the first node; A tenth switching element configured to discharge the first node to the second voltage source in response to the third voltage source charged in the second node; An eleventh switching element configured to discharge the first node to the second voltage source in response to the fourth voltage source charged to the third node; A twelfth switching element for discharging the first node to the second voltage source in response to the scan pulse from the next stage; A thirteenth switching element configured to output a scan pulse in response to the first voltage source charged in the first node, and supply the scan pulse to the gate line, the next stage stage, and the previous stage stage; A fourteenth switching element configured to supply a second voltage source to the gate line in response to the third voltage source charged in the second node; And, And a fifteenth switching element for supplying a second voltage source to the gate line in response to the fourth voltage source charged to the third node. The method of claim 19, And a pulse width between clock pulses output from the timing controller is overlapped with each other by a predetermined portion. The method of claim 19, And a pulse width section overlapping the clock pulses and a pulse width section overlapping the scan pulses have the same width. The method of claim 19, A first dummy stage for outputting scan pulses in response to scan pulses from the last stage of the stages and providing them as inputs to the stages of the last previous stage, and responding to the scan pulses from the first dummy stages And a second dummy stage configured to output a scan pulse and provide it as an input to the stage of the last stage. The method of claim 19, And the first voltage is a negative DC voltage, and the second voltage is a positive DC voltage. The method of claim 19, Each of the clock pulses is repeatedly output with a predetermined period, and each of the clock pulses are sequentially output to each other. The method of claim 19, And the start pulse is supplied to a first stage which outputs a scan pulse first of the stages. The method of claim 19, And the first to fifteenth switching elements are amorphous TFT (Thin Film Transistor). The method of claim 19, And the stages are built in the liquid crystal panel. In response to clock pulses from the timing controller, a shift including a plurality of stages sequentially outputting a plurality of scan pulses so that a predetermined section of their pulse widths overlap each other, and sequentially supplying them to the gate lines of the liquid crystal panel. In the register, Each stage said, A first switching element for charging the first node with a first voltage source in response to a start pulse or a scan pulse from a previous stage; A second switching element for discharging the second node to the second voltage source in response to the first voltage source charged to the first node; A third switching element configured to discharge the third node to the second voltage source in response to the first voltage source charged in the first node; A fourth switching element turned on or off in response to a third voltage source having a different polarity for each frame, and outputting the third voltage source at turn-on; A fifth switching device configured to charge a second node with a third voltage source in response to the third voltage source output from the fourth switching device; A sixth switching element discharging the first node to the second voltage source in response to the third voltage source charged to the second node; A seventh switching element configured to discharge the third node to the second voltage source in response to the third voltage source charged in the second node; An eighth switching device which turns off the fifth switching device by supplying a second voltage source to the gate terminal of the fifth switching device in response to the first voltage source charged in the first node; A ninth switching element for turning off the fifth switching element by supplying a second voltage source to the gate terminal of the fifth switching element in response to a start pulse or a scan pulse from a previous stage; A tenth switching element for turning off the fifth switching element by supplying a second voltage source to the gate terminal of the fifth switching element in response to a start pulse or a scan pulse from a previous stage; An eleventh switching element having a different polarity for each frame and being turned on or off in response to a fourth voltage source having a polarity inverted to the third voltage source, and outputting the fourth voltage source when turned on; A twelfth switching device configured to charge a third node with the fourth voltage source in response to a fourth voltage source output from the eleventh switching device; A thirteenth switching element discharging the first node to the second voltage source in response to the fourth voltage source charged to the third node; A fourteenth switching element configured to discharge the second node to the second voltage source in response to the fourth voltage source charged to the third node; A fifteenth switching element that turns off the twelfth switching element by supplying a second voltage source to the gate terminal of the twelfth switching element in response to the first voltage source charged in the first node; A sixteenth switching element that turns off the twelfth switching element by supplying a second voltage source to the gate terminal of the twelfth switching element in response to a start pulse or a scan pulse from a previous stage; A seventeenth switching element that turns off the twelfth switching element by supplying a second voltage source to the gate terminal of the twelfth switching element in response to a start pulse or a scan pulse from a previous stage; An eighteenth switching element for discharging the second node to the second voltage source in response to the start pulse or the scan pulse from the previous stage; A nineteenth switching element for discharging the third node to the second voltage source in response to the start pulse or the scan pulse from the previous stage; A twentieth switching element that discharges the first node to a second voltage source in response to a scan pulse from the next stage; A twenty-first switching element configured to output a scan pulse in response to the first voltage source charged in the first node, and supply the scan pulse to the gate line, the next stage, and the previous stage; A twenty-second switching element configured to supply a second voltage source to the gate line in response to a third voltage source charged in the second node; And, And a twenty-third switching element for supplying a second voltage source to the gate line in response to the fourth voltage source charged to the third node. The method of claim 28, And a pulse width between clock pulses output from the timing controller is overlapped with each other by a predetermined portion. The method of claim 28, And a pulse width section overlapping the clock pulses and a pulse width section overlapping the scan pulses have the same width. The method of claim 28, A first dummy stage for outputting a scan pulse in response to a scan pulse from a stage of the last stage of the stages, and providing this as an input to a stage of the last stage, and in response to a scan pulse from the first dummy stage And a second dummy stage which outputs a scan pulse and provides it as an input to the stage of the last stage. The method of claim 28, And the first voltage is a negative DC voltage, and the second voltage is a positive DC voltage. The method of claim 28, Each of the clock pulses is repeatedly output with a predetermined period, and each of the clock pulses are sequentially output to each other. The method of claim 28, And the start pulse is supplied to a first stage which outputs a scan pulse first of the stages. The method of claim 28, And the first to twenty-third switching elements are amorphous thin film transistors (TFTs). The method of claim 28, And the stages are built in the liquid crystal panel. In response to clock pulses from the timing controller, a shift including a plurality of stages sequentially outputting a plurality of scan pulses so that a predetermined section of their pulse widths overlap each other, and sequentially supplying them to the gate lines of the liquid crystal panel. In the register, Each stage said, A first switching element for charging the first node with a first voltage source in response to a start pulse or a scan pulse from a previous stage; A second switching element for discharging the second node to the second voltage source in response to the first voltage source charged to the first node; A third switching element configured to discharge the third node to the second voltage source in response to the first voltage source charged in the first node; A fourth switching element turned on or off in response to a third voltage source having a different polarity for each frame, and outputting the third voltage source at turn-on; A fifth switching device configured to charge a second node with a third voltage source in response to the third voltage source output from the fourth switching device; A sixth switching element discharging the first node to the second voltage source in response to the third voltage source charged to the second node; A seventh switching element configured to discharge the third node to the second voltage source in response to the third voltage source charged in the second node; An eighth switching element for turning off the fifth switching element by supplying a second voltage source to the gate terminal of the fifth switching element in response to the first voltage source charged in the first node; A ninth switching element for turning off the fifth switching element by supplying a second voltage source to the gate terminal of the fifth switching element in response to a start pulse or a scan pulse from a previous stage; A tenth switching element for turning off the fifth switching element by supplying a second voltage source to the gate terminal of the fifth switching element in response to a start pulse or a scan pulse from a previous stage; An eleventh switching element having a different polarity for each frame and being turned on or off in response to a fourth voltage source having a polarity inverted to the third voltage source, and outputting the fourth voltage source when turned on; A twelfth switching device configured to charge a third node with the fourth voltage source in response to a fourth voltage source output from the eleventh switching device; A thirteenth switching element discharging the first node to the second voltage source in response to the fourth voltage source charged to the third node; A fourteenth switching element configured to discharge the second node to the second voltage source in response to the fourth voltage source charged to the third node; A fifteenth switching element that turns off the twelfth switching element by supplying a second voltage source to the gate terminal of the twelfth switching element in response to the first voltage source charged in the first node; A sixteenth switching element that turns off the twelfth switching element by supplying a second voltage source to the gate terminal of the twelfth switching element in response to a start pulse or a scan pulse from a previous stage; A seventeenth switching element that turns off the twelfth switching element by supplying a second voltage source to the gate terminal of the twelfth switching element in response to a start pulse or a scan pulse from a previous stage; An eighteenth switching element for discharging the second node to the second voltage source in response to the start pulse or the scan pulse from the previous stage; A nineteenth switching element for discharging the third node to the second voltage source in response to the start pulse or the scan pulse from the previous stage; A twentieth switching element that discharges the first node to a second voltage source in response to a scan pulse from the next stage; A twenty-first switching element configured to output a scan pulse in response to the first voltage source charged in the first node, and supply the scan pulse to the gate line, the next stage, and the previous stage; A twenty-second switching element configured to supply a second voltage source to the gate line in response to a third voltage source charged in the second node; A twenty-third switching element configured to supply a second voltage source to the gate line in response to the fourth voltage source charged in the third node; A twenty-fourth switching element configured to output a scan pulse in response to the first voltage source charged in the first node and to supply the scan pulse to the gate line, the next stage, and the previous stage; A twenty fifth switching element configured to supply a second voltage source to the gate line in response to a third voltage source charged in the second node; And, And a twenty sixth switching element for supplying a second voltage source to the gate line in response to the fourth voltage source charged to the third node. The method of claim 37, And a pulse width between clock pulses output from the timing controller is overlapped with each other by a predetermined portion. The method of claim 37, And a pulse width section overlapping the clock pulses and a pulse width section overlapping the scan pulses have the same width. The method of claim 37, A first dummy stage for outputting a scan pulse in response to a scan pulse from a stage of the last stage of the stages, and providing this as an input to a stage of the last stage, and in response to a scan pulse from the first dummy stage And a second dummy stage which outputs a scan pulse and provides it as an input to the stage of the last stage. The method of claim 37, And the first voltage is a negative DC voltage, and the second voltage is a positive DC voltage. The method of claim 37, Each of the clock pulses is repeatedly output with a predetermined period, and each of the clock pulses are sequentially output to each other. The method of claim 37, And the start pulse is supplied to a first stage which outputs a scan pulse first of the stages. The method of claim 37, And the first to twenty-sixth switching elements are amorphous TFT (Thin Film Transistor). The method of claim 37, And the stages are built in the liquid crystal panel.

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