KR950005257Y1 - Driving devices for lcd - Google Patents

Abstract

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Description

LCD panel driver

1 is a detailed circuit diagram of a liquid crystal display panel driving apparatus according to an embodiment of the present invention.

2 is a scanning diagram of a liquid crystal display panel according to an embodiment of the present invention.

The present invention relates to a liquid crystal display panel driving apparatus for driving a liquid crystal display panel which outputs a desired image or information by using a liquid crystal display (LCD) panel. Accordingly, in order to sequentially scan image signals to a liquid crystal display device, the image signals are scanned two rows at a time to improve the output speed of the image signals and to solve the problem of image signal persistence on the full screen. It relates to a drive device.

Conventional liquid crystal display panel is mainly due to the difficulty in the manufacturing process of a thin film transistor (TFT) that serves to switch each pixel electrode corresponding to the desired time in sequence to form a small form It was. In addition, a scanning method for reproducing a desired image on a liquid crystal display is also sequentially selected from the first row, and then a column corresponding to the selected row is sequentially designated to drive the pixel electrode to the input image information signal. The corresponding image is reproduced on the liquid crystal display panel.

However, when reproducing images by scanning rows of rows by designating the corresponding rows in sequence as described above, when moving to the lower side while assembling the upper image, the upper image which is already assembled is deleted sequentially. There is a problem of an afterimage in which a full screen image remains.

In addition, since the development of electronic technology has led to the trend of the large screen, the conventional method is to drive the large liquid crystal display panel having 480 scan lines as 240 scan lines having image information increase to 480. In the case of sequentially reproducing images by using a very long time, it is very slow to reproduce an image of one frame, and thus the image reproduction speed becomes very slow and the problem of afterimages becomes more serious.

Therefore, the principle of this design scans two screens in odd field and even field using the interlaced scanning principle used in NTSC (National Television System Committee) color television. After that, a method of reproducing one image frame is used.

However, the scanning method can reproduce one completed frame using two screens obtained by vertically selecting two rows at a time and horizontally scanning sequentially.

The conventional driving circuit of the liquid crystal display panel is disclosed in "Drive circuit of the liquid crystal display device" of Korean Utility Model Application Publication No. 92-1006 (Application Date: May 1, 1986 AD). However, the above-mentioned driving circuit of the liquid crystal display device is to improve the luminance gradient occurring at the top and bottom of the screen due to the large voltage drop generated when the current flowing through the thin film transistor in the bottom row is long. Has a different purpose.

Therefore, the object of the present invention is to solve the above-mentioned problems, and when reproducing an image on a liquid crystal display panel, instead of sequentially scanning and reproducing the image, scanning two rows at the same time to shorten the reproduction time of the image, thereby causing an afterimage problem. In order to solve the problem, the image can be quickly reproduced on the liquid crystal display panel.

In order to achieve the above object, the structure of the present invention is the inverter connected to the scan control terminal, and the scan control signal is sequentially selected two rows of the liquid crystal display panel according to the n input signals applied sequentially, so that two rows are scanned at the same time. In addition, the scan control signal is inverted and composed of n drivers for scanning sequentially two rows again according to the n input signals applied.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 is a detailed circuit diagram of a liquid crystal display panel driving apparatus according to an embodiment of the present invention, and FIG. 2 is a scanning diagram of a liquid crystal display panel according to an embodiment of the present invention.

Referring to FIG. 1, a configuration of a liquid crystal display panel driving apparatus according to an embodiment of the present invention will be described.

Inverter INV1 with input terminal connected to scan control terminal (-O / E), and input terminal with row drive input terminals I1 to I240, and scan control terminal (-O / E) or inverter (INV1). N drive units 10 to 240 connected to an output terminal and a control terminal of the < RTI ID = 0.0 >), < / RTI > The self-liquid crystal display panel 1 includes a column driver 2 connected to each of p columns.

The first driving unit 10 includes a transmission gate T11 and T13 having an input terminal connected to the first row driving input terminal I1 and a gate terminal connected to an output terminal of the inverter INV1, and a first driving unit 10. Transmission gates T12 and T14 having an input terminal connected to the row drive input terminal I1 and a gate terminal connected to the scan control terminal (-0 / E), and a first input terminal grounded and a second input terminal. The inverter is connected to the OR gate OR10 to which the output terminal of the transmission gate T1 is connected and the output terminal of the OR gate OR10 in series, and the output terminal P11 is connected to the liquid crystal display panel 1. (INV11, INV12), OR gate OR11 in which the first input terminal is connected to the output terminal of the transmission gate T12, and the second input terminal is connected to the output terminal of the transmission gate T13, and OR gate. Are connected in sequence to the output terminal of (OR11) (P12) that consists of an inverter (INV13, INV14) connected to the liquid crystal display panel (1).

The second to 230th driving units 10 to 230 are composed of transmission gates Tn1 and Tn3 having an input terminal connected to an n-row driving input terminal In and a gate terminal connected to an output terminal of the inverter INV1. ), The transmission gates Tn2 and Tn4 having the input terminal connected to the n-row drive input terminal In and the gate terminal connected to the scan control terminal (-O / E), and the first input terminal n-1. OR gate ORn0 connected to the output terminal of the driver ((n-1) 0) transmission gate T (n-1) 4 and a second input terminal connected to the output terminal of the transmission gate Tn1. Inverters INVn1 and INVn2 having the output terminal Pn1 connected to the liquid crystal display panel 1 connected in series with the output terminal of the OR gate ORn0 and the first input terminal of the output of the transmission gate Tn2. OR gate ORn1 connected to the terminal and the second input terminal connected to the transmission gate Tn3, and OR gate. The inverters INVn3 and INVn4 are connected in series with the output terminal of ORn1 and the output terminal Pn2 is connected to the liquid crystal display panel 1.

The last 240 driver 240 is composed of transmission gates T241 and T143 having an input terminal connected to the 240 th drive input terminal I240 and a gate terminal connected to an output terminal of the inverter INV1. Transmission gates T242 and T244 having an input terminal connected to the 240-row driving input terminal I240 and a gate terminal connected to the scan control terminal (-O / E), and the first input terminal 230 driving unit 230. Is connected in series with an output terminal of the OR gate OR240 connected to an output terminal of the transmission gate T234 of the second input terminal connected to an output terminal of the transmission gate T241, and an output terminal of the OR gate OR240. Inverters INV241 and INV242 having an output terminal P241 connected to the liquid crystal display panel 1, a first input terminal connected to an output terminal of the transmission gate T242, and a second input terminal connected to a transmission gate ( Connected to the output terminal of T243). OR it consists of a gate (OR241) and, OR inverter (INV243, INV244) that are are sequentially connected and the output terminal (P242) connected to the liquid crystal display panel (1) to the output terminal of the gate (OR11).

Detailed operation according to the embodiment of the present invention made as described above is as follows.

First, when the low level “L” signal is input to the scan control terminal (-O / E), the high level “H” is output from the inverter INV1. Therefore, the transmission gate is connected to the output terminal of the inverter INV1. Both Tn1 and Tn3 are in a conductive state.

When the high level "H" is input to the first row driving input terminal I1, "H" is output to the transmission gates Tn1 and Tn3, and is applied to the input terminals of the OR gates OR10 and OR11. OR11) displays “H”. Therefore, "H" is output to the output terminals P11 and P12 via the inverters INV11 to INV14 to select two rows of the liquid crystal display panel 1.

When the first and second rows of the liquid crystal display panel 1 are selected by the signal applied to the first row driving input terminal I1, the column driver 2 sequentially applies control signals to sequentially select the selected two rows of columns. By driving the pixel electrodes of the corresponding liquid crystal according to the image signal of the portion not shown, the desired images may be sequentially scanned.

When the selected two rows are scanned according to the video signal by the column control signal, the first row drive input terminal I1 is converted to low level “L” and the second row drive input terminal I2 is converted to high level “H”. do.

Therefore, the transmission gates T21 and T22 of the second driver 20 are turned on to output the high level “H” to the inverters INV21 and INV24 so that the third and fourth rows of the liquid crystal display panel 1 are selected and the fissures The rows of two rows selected by the eastern part 2 are sequentially scanned.

In the same manner as described above, while the scan control terminal (-O / E) is the low level "L", the signal is input as the high level "H" signal is sequentially applied from the first row drive input terminal I1 to the 240th row drive control terminal. When high level “H” is applied to the terminal, two rows can be selected at a time so that two rows can be scanned one by one.

After scanning both rows sequentially, if the 240th row drive input terminal I240 is converted from “H” to “L”, the scan control terminal (-O / E) becomes “H”, which is a high level.

Therefore, the transmission gates Tn2 and Tn4, which are “L” output to the inverter INV1 and whose gate terminals are connected to the scan control terminal (-O / E), become conductive state.

When the high level “H” is input to the first row driving input terminal I1, the “H” is output to the transmission gates T12 and T14, and is applied to the input terminals of the OR gates OR11 and OR20 to be applied to the OR gates OR11 and OR20) outputs “H”. Therefore, the "H" is outputted to the output terminals P12 and P21 through the inverters INV13 and INV14 of the first driving unit 10 and the inverters INV21 and INV22 of the second driving unit 20, and thus, the liquid crystal display panel 1. You will select two rows of.

When the second and third rows of the liquid crystal display panel 1 are selected by the signal applied to the first row driving input terminal I, the column driver 2 sequentially selects the selected two rows of columns by applying a control signal. Thus, the corresponding pixel electrode is operated according to an image signal of a part not shown so that desired images can be sequentially reproduced on the liquid crystal panel.

When the selected two rows are scanned according to the video signal by the column control signal, the first row drive input terminal I1 is converted to low level “L” and the second row drive input terminal I2 is converted to high level “H”. do.

Therefore, the transmission gates T22 and T24 of the second driver 20 are turned on to output the high level “H” to the inverters INV24 and INV32 so that the fourth and fifth rows of the liquid crystal display panel 1 are selected and the fissures The two rows selected by the eastern part 2 are sequentially scanned.

Therefore, when the low level “L” is input to the scan control terminal (-O / E), two rows are sequentially selected and scanned according to the signal applied to the row input terminal as shown in FIG. 2a, and the scan control terminal (-O / E) is scanned. When the high level “H” is input, two rows are selected and scanned in sequence as shown in FIG. 2B. Therefore, the field scanned when the scan control terminal (-O / E) is “H” and the field scanned when “L” are added together. One image frame can be reproduced.

Therefore, the effect of this design is to select the same row twice and scan the image signal by sequentially selecting the rows one by one, so that a clearer image can be reproduced. By selecting two rows at the same time, the scanning time is reduced accordingly. As a result, video reproduction time is greatly shortened and afterimage on the full screen is significantly reduced. In addition, since the liquid crystal display panel having 480 scan lines can be processed with 240 input signals, the occupied area used when implementing the circuit can be reduced.

Claims (3)

Inverting means (INV1) for inverting the state of the scan control signal (-O / E) whose signal state varies depending on the field; The conduction state of the signal is controlled by the scan control signal (-O / E) in the inverted state and the gate signal corresponding to the output state of the inverting means (INV1), and according to the plurality of driving signals (I-In) sequentially input. A plurality of switching means Tn1 to Tn4 for selecting rows of the liquid crystal display panel 1 adjacent to each other; The output signals of the switching means Tn1 to Tn4 which are adjacent to each other are input, and are adjacent to each other by the operation states of the plurality of switching means Tn1 to Tn4 and the plurality of driving signals I1 to In that are sequentially input. A liquid crystal display panel drive device comprising a plurality of signal combinations for outputting drive signals in a row. 2. The liquid crystal display panel drive device according to claim 1, wherein the plurality of switching means (Tn1 to Tn4) is formed of a transmission gate whose conduction state is changed according to a state of a signal input to the gate terminal. 2. The logical sum means (ORnO to ORn1) according to claim 1, wherein the plurality of signal combinations comprise logic sum means (ORnO to ORn1) to which output signals of adjacent switching means (Tn1 to Tn4) are input to first and second input terminals, respectively. An output signal of the means ORnO to ORn1 is input to an input terminal, and comprises a plurality of inverting means INVn1 to INVn2 for allowing simultaneous selection of each adjacent row of the liquid crystal display panel 1. LCD panel driving device.