JPH06149174A - Liquid crystal display - Google Patents

Abstract

(57) [Abstract] [Purpose] The purpose is to reduce the number of times the drive voltage is inverted, thereby reducing the charging current and power consumption, and also to reduce flicker regardless of the display pattern. . A data line 68 is formed on an inner surface 70 'of one of the two glass substrates 64 and 65 facing each other.
A switching element 61 having a gate line 67 and a gate terminal connected to the gate line 67 and driven by a signal on the gate line 67 is provided, and at the same time, one terminal of the switching element 61 is connected to the data line 68. And the other terminal of the switching element 61 is connected to a plurality of pixels 62 and arranged in a matrix, and the common electrode 63 is arranged in the liquid crystal panel 60. 63 is formed by dividing it into a plurality of groups, for example, two sets,
A liquid crystal panel configured to operate a predetermined control unit so as to apply a voltage so that the polarities of the voltages applied to the respective groups are opposite to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a liquid crystal panel in which switching elements are arranged and its driving means.

[0002]

2. Description of the Related Art In recent years, with the demand for lower power consumption of personal computers and the like, lower power consumption is also required for each component used therein. Although the liquid crystal display device used for the display device originally has low power consumption, it is necessary to further reduce the power consumption in order to downsize the device and improve long-term operation.

Here, a schematic structure of a conventional liquid crystal display device 100 is shown in FIG. 8, in which a liquid crystal panel 60 and a control circuit 1 are provided.
0, gate driver circuit 20, common waveform generation circuit 30
And a data driver circuit 40. In the circuit, a clock signal or a latch signal is supplied from the control circuit 10 to the driver circuit 40 at the same time as each data.

Further, for example, a scan signal is supplied from the control circuit 10 to the gate driver circuit 20, and based on this, a gate signal G1, G2 ... Is given from the gate driver circuit 20 to the liquid crystal panel 60. Supplied.
On the other hand, from the upper data driver circuit 40 to the liquid crystal panel 6
Predetermined data D1 to Dn for 0 is the liquid crystal panel 6
0 is supplied to each.

A common electrode signal VCOM is supplied from the common waveform generating circuit 30 to the liquid crystal panel 60. Here, in the conventional liquid crystal display device having such a configuration, the liquid crystal panel 60 used is one in which the switching elements 61 and the pixel portions 62 are arranged in a matrix, and the details thereof are shown in FIG. As shown in FIG. 6, a common electrode (common electrode) 63 is uniformly arranged and formed on the inner surface of one glass substrate 64 of the liquid crystal panel 60, which is composed of two glass substrates 64 and 65. The pixel portion 62 is disposed on the inner surface of the glass substrate 65 above the other electrode 69.
There is provided a switching element 61 which is connected to 2.

The switching element 61 is connected to a gate line 67 (G1, G2) and its gate terminal, and the other terminal portion is connected to a data line 68 (D1 to D4). Further, the conventional driving method of the liquid crystal display device will be described with reference to the timing chart of FIG. 7. In the conventional driving method, the common electrode (VCOM) is arranged in front of the glass surface facing the pixel electrode. It is the voltage (common voltage) supplied to the transparent electrode.

In the past, it was necessary to reverse the polarities of the common voltage and the data voltage (D1, D2) in one horizontal line period. Inverting the polarities of the common voltage and the data voltage eliminates the fluctuation of the pixel voltage due to the parasitic capacitance of the switching element 61 in the liquid crystal panel 60 or the wiring capacitance in the data line, and the flicker phenomenon occurs. Are needed to control.

[0008]

In the conventional liquid crystal display device, it is necessary to use alternating current in order to frequently invert the polarities of the common voltage and the data voltage as described above. Therefore, the liquid crystal panel, which is a capacitive load, is charged and discharged, but since the charge and discharge is proportional to the magnitude of the frequency, the charge and discharge increases as the frequency increases and the polarity of the voltage reverses. Electric current flows and power is consumed.

Further, as described above, since the data line also has a wiring capacitance, a charging / discharging current flows even when the polarity of the voltage is reversed, resulting in power consumption. Further, although the polarities of the pixel voltages are inverted in the vertical direction, they have the same polarity in the horizontal direction, so that flicker may occur depending on the display pattern. The purpose of the present invention is to
It is possible to solve the problems in the related art, reduce the number of times of polarity inversion of the drive voltage, reduce the charge / discharge current, reduce the power consumption, and further reduce the flicker regardless of the display pattern. It is intended.

[0010]

In order to achieve the above-mentioned object, the present invention adopts the technical constitution as described below. That is, a data line, a gate line, a switching element that is connected to the gate line and is driven by a signal of the gate line, and a switching element that is driven by a signal on the gate line, on the inner surface of one of the two glass substrates that are arranged opposite In a liquid crystal panel in which a plurality of pixels connected to each other are arranged in a matrix and a common electrode is arranged on the opposite inner surface of the other glass substrate, the common electrode is divided into a plurality of groups. A liquid crystal display device having a liquid crystal panel configured so that the voltages applied to the respective groups are applied such that the polarities thereof are opposite to each other.

[0011]

In the liquid crystal display device according to the present invention, when the liquid crystal panel in the conventional liquid crystal display device is driven, the polarity of the voltage of the common electrode is inverted for each gate line. Instead, by improving the structure of the liquid crystal panel, the polarity of the voltage applied to the common electrode is inverted every frame, thereby significantly reducing the charging / discharging cycle in the liquid crystal panel. As a result, it is possible to significantly reduce the amount of power consumption used in the liquid crystal display device.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of the liquid crystal display device according to the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a liquid crystal panel 60 used in a liquid crystal display device 100 according to the present invention.
3 is a plan view showing a configuration example of FIG.

That is, the structure of the liquid crystal panel 60 of the liquid crystal display device 100 shown in FIG. 1A and FIG. 1B is such that the two substrates out of the two glass substrates 64, 65 arranged opposite to each other. On the inner surface 70 'facing each other, the data lines 68 (D1, D2, D3,
D4), a gate line 67 (G1, G2, G3), a switching element 61 having a gate terminal connected to the gate line 67 and driven by a signal on the gate line 67, which is composed of, for example, a transistor or the like. At the same time when the switching element 61 is provided, one terminal of the switching element 61 is connected to each of the data lines 68, and each of the other terminals of the switching element 61 is connected to the plurality of pixels 62. And the pixels 62 are arranged in a matrix, and a common electrode, that is, a common electrode 63 is arranged on the facing inner surface 70 of the other glass substrate 64.
In the above, the common electrode 63 is provided in a plurality of groups, for example, two sets,
A liquid crystal panel is shown which is formed by being divided into a plurality of groups and is configured to apply a voltage by operating predetermined control means so that the polarities of the voltages applied to the respective groups are opposite to each other. .

The common electrode 63 in the liquid crystal panel 60 according to the present invention is divided into two wiring groups as shown by VC1 and VC2, for example, as understood from FIG. 1A. Each of them is capable of driving a predetermined number of pixel groups 62 with individual voltages. Of course, the common electrode 63 provided in the liquid crystal panel 60 of the conventional liquid crystal display device 100 is integrally and planarly formed in the entire liquid crystal panel 60, whereas in the present invention. As shown in FIG. 1A, for example, the common electrode 63 has stripe shapes such as a strip shape, a thin line shape, and a long shape arranged according to a predetermined pattern between the pixel groups 62 arranged in the matrix. Are those that have.

The plurality of stripe-shaped electrodes 63 in the present invention are, for example, parallel to the data lines 68 in the liquid crystal panel 60 and the gate lines 67.
Of the plurality of common electrode stripes 63-1, 63-2, 63-3, 63-4, etc. arranged in parallel. , Every other common electrode group, that is, the common electrode stripe 63-
It is divided into a first group consisting of 1, 63-3 and a second group consisting of common electrode stripes 63.2, 63-4, and voltages having different electrodes are applied to each group. It is something to do.

That is, the first group in FIG. 1A is VC1, and the second group is VC2.
For example, when a + voltage is applied to the first group, VC1, a -voltage is applied to the second group VC2. That is, in the liquid crystal panel 60 according to the present invention, a plurality of striation common electrodes 63 arranged in parallel between the pixels 62 arranged in a matrix are alternately applied. The polarities of the voltages are different.

On the other hand, in the liquid crystal panel 60 of the present invention, a plurality of pixel groups 62 arranged along the data line direction are alternately arranged on both sides of the pixel column. The two common electrodes are configured to be connected to the common electrode 63 arranged on one side. Specifically, referring to FIG. 1A, for example, the pixels P11, P22, and P13 are alternately connected to the common electrode 63-1 in the order of arrangement of the gate lines 67 in a staggered pattern, and the common electrode 63-1 is connected to the common electrode 63-1. Is a pixel in which the pixels P21, P32, and P23 are connected alternately and in a staggered manner in the order in which the gate lines 67 are arranged.

Further, in the present invention, it is preferable that the polarity of the data line is inverted every other line. That is, in the present invention, each of the matrix-shaped pixel groups 62 arranged on the liquid crystal panel 60 is adjacent to other adjacent pixels arranged vertically or horizontally. Are configured so that the polarities of the driving voltages are different from each other, which has an effect of completely preventing the occurrence of flicker, and at least the polarity of the voltage of the common electrode is set to 1
Since it is improved by simply changing it for each frame, it becomes possible to drive at a low frequency, and it is possible to significantly reduce power consumption.

Referring to FIG. 1 in more detail, FIG.
Each of P11 to P43 indicates a pixel electrode 62, and one switching element 61 is arranged in one pixel 62. On the other hand, D1 to D5 are data lines to which a voltage according to display data is supplied.

Further, G1 to G3 are gate lines,
The selection voltage of the display line is supplied to each gate terminal of the switching element 61. Further, VC1 and VC2 are common electrode terminals, respectively. That is, the common electrode VC1 is connected to each of the pixels P11, P22, P13, and further connected to the pixels P31, P42, P33 skipping one data line. Similarly, the common electrode VC2 is connected to each of the pixels P21, P3.
2, P23, P41, P43.

That is, as a basic mode of the present invention, as described above, the common electrode is divided into a plurality of groups, and the polarities of the voltages supplied to the respective common electrode groups are made different from each other. That is, the pixels constituting the pixel column arranged in the data line direction on each of the common electrodes are alternately connected to one common electrode in a staggered manner, and the voltage polarity of each data line is set to 1 Reversing every other line produces the desired result.

FIG. 2 is a timing chart when the liquid crystal panel 60 in the liquid crystal display device 100 according to the present invention shown in FIG. 1 is used, and the common electrode V
The voltage waveforms of C1 and VC2 have polarities opposite to each other within one frame, and the relationship is inverted every frame. Further, in the present invention, as described above, since it is necessary to invert the polarity of the voltage of the data line for each line, the data signals D1 to D5 are changed to D.
It is configured to be divided into a group of 1, D3, D5 and a group of D2, D4, and the voltage polarities of both groups are inverted and input.

That is, in the first group of data lines, if D1, D3, and D5 are data of positive polarity, the second line is used.
In the data line of the group (2), D2 and D4 are data of negative polarity. That is, the data voltages having the opposite polarities are applied to the odd lines and the even lines in the data lines so that the polarities are inverted every horizontal period, and in the first frame, the first polarities of the data are set. Is set to start with + polarity, it is set to start with − polarity in the second frame.

On the other hand, the voltages VC1 and VC2 related to the respective groups of the common electrode 63 are voltages of opposite polarities, and the polarities thereof are inverted every frame. Waveforms P11, P12, P21, and P22 in FIG. 2 are drive waveforms applied to the pixels P11, P12, P21, and P22 in FIG. 1, respectively, and the pixel P11 and the pixel P22 are at “H” level. Pixel P12 and Pixel P21
Is set to the “L” level. Therefore, in the matrix of the liquid crystal panel 60, the polarity of the voltage of the common electrode is inverted for each display line and each column, and the checkered pattern is formed. It will take an array form.

As shown in FIG. 9, the schematic configuration of the liquid crystal display device 100 according to the present invention includes a liquid crystal panel 60, a control circuit 10, a gate driver circuit 20, and a common waveform generating circuit 3.
0 and upper data (eg, even data, first data group) driver circuit 40 and lower data (eg, odd data, second data group) driver circuit 50.

In the circuit, from the control circuit 10,
A clock signal or a latch signal is supplied to the driver circuits 40 and 50 at the same time as each data. Further, for example, a scan signal is supplied from the control circuit 10 to the gate driver circuit 20, and based on the scan signal,
1 from the gate driver circuit 20 to the liquid crystal panel 60
Gate signals G1, G2 whose polarity is changed for each frame ...
Is supplied.

On the other hand, the data D1 having a predetermined polarity from the upper data driver circuit 40 to the liquid crystal panel 60 is
Further, the lower data driver circuit 50 supplies the liquid crystal panel 60 with predetermined data D2 having a polarity different from that of the data D1. Also, two sets of common electrode signals VC1 having voltages of opposite polarities to the liquid crystal panel 60 from the common waveform generation circuit 30.
And VC2 are supplied.

FIG. 3 is a plan view showing an example of a liquid crystal panel having the above-mentioned structure in the liquid crystal panel 60 used in the liquid crystal display device according to the present invention. In FIG. 3, reference numerals 40 and 50 correspond to the upper data (for example, even data) driver circuit 40 and the lower data (for example, odd data) driver circuit 50 in the liquid crystal display device 100 shown in FIG.
Reference numeral 20 corresponds to the gate driver 20 shown in FIG.

In each pixel portion 62, the common electrode VC1
The pixel portion connected to the pixel electrode is hatched in a diagonal shape, and the pixel portion connected to the common electrode VC2 is hatched in a dot shape. Therefore, the arrangement of the common electrode of the liquid crystal panel 60 in the present invention is You can understand at a glance. Next, another specific example of the liquid crystal display device 100 according to the present invention will be described.

FIG. 4 shows the liquid crystal panel 60 according to the present invention.
FIG. 11 is a plan view illustrating another configuration of the liquid crystal panel 6
The feature of 0 is that the data line is bent and arranged so as to be connected to the pixels of another adjacent data line every other gate. That is, as shown in FIG. 1, the data line D1 is first connected to the switching element of the pixel P11 that is controlled by the gate line G1, and then moved to the adjacent pixel column and the pixel P22 that is controlled by the gate line G2. After being connected to the switching element of the pixel P, the pixel P returns to the original column again and is controlled by the gate line G3.
It is configured to be connected to 13 switching elements.

The same structure applies to the data lines D2 to D5. The common electrode 6 in the specific example
The configuration of 3 is similar to that of FIG. In the configuration of the liquid crystal panel of the present invention, the pixel groups are connected to each of the common electrodes in a zigzag pattern, and the data lines and the stripe lines of the common electrodes are parallel to each other. In a specific example, the data line is further bent with respect to the common electrode, and a certain data line is connected to a part of another pixel column arranged along another adjacent data line. In addition, the arrangement returns to the original position, so to speak, in a zigzag arrangement.

That is, in this example, the voltage polarity of each common electrode divided into two types of groups can be inverted for each frame, and the voltage of each data supplied to the data line can be changed. It is also possible to invert the polarity for each frame, and for the same reason as above, it is possible to significantly reduce the power consumed in the liquid crystal display device.

Further, in the present invention, in the liquid crystal display device 100 including the liquid crystal panel 60 and the driver circuits 20, 40 and 50 for driving the liquid crystal panel 60 as described above, the N data lines are provided. And N + 1, the drive voltages of the data lines are reversed in polarity to perform line inversion, and drive voltages of opposite polarities are applied to the two common electrodes, and at the same time, the respective polarities are inverted for each frame. It has been done.

Further, as another specific example of the present invention, the liquid crystal panel 60 described above and the liquid crystal panel 60 are described.
Display device 100 including each driver circuit for driving
In this case, the polarities of the driving voltages of the N data lines and the N + 1 data lines are reversed, and the inversion is performed for each frame. Further, at the same time, the driving voltages of the opposite polarities are applied to the two common electrodes. It is so constructed that each polarity is inverted for each frame.

[0035]

As described above, according to the present invention,
In the conventional method, the polarity of the common electrode is inverted by performing the line inversion, whereas the frame inversion drives the charge / discharge current generated when the voltage polarity of the common electrode is inverted. Since the size can be reduced, the power consumption of the liquid crystal display device can be reduced.

Further, in the present invention, the occurrence of flicker can be eliminated regardless of the display pattern, which can greatly contribute to the improvement of the display quality of the screen and the image. Further, in the present invention, the polarity of the data voltage can be inverted every frame by changing the connection of the data line, so that the power consumption can be further reduced.

[Brief description of drawings]

FIG. 1A is a plan view illustrating a configuration example of a liquid crystal panel used in a liquid crystal display device according to the present invention.
B is a partial cross-sectional view thereof.

FIG. 2 is a timing chart showing an operation of each unit in the liquid crystal panel shown in FIG.

FIG. 3 is a plan view showing an example of a liquid crystal panel used in the liquid crystal display device according to the present invention.

FIG. 4 is a plan view showing another configuration of a liquid crystal panel used in the liquid crystal display device according to the present invention.

5 is a timing chart showing the operation of each part in the liquid crystal panel shown in FIG.

6A is a plan view showing a configuration example of a liquid crystal panel used in a conventional liquid crystal display device.
B is a partial cross-sectional view thereof.

FIG. 7 is a timing chart for explaining the operation of each part of the conventional liquid crystal panel shown in FIG.

FIG. 8 is a diagram illustrating a schematic configuration of a conventional liquid crystal display device.

FIG. 9 is a diagram illustrating an outline of a configuration of a liquid crystal display device according to the present invention.

[Explanation of symbols]

 100 ... Liquid crystal display device 10 ... Control circuit 20 ... Gate driver circuit 30 ... Common electrode waveform generation circuit 40 ... Data driver (upper data, even data) 50 ... Lower data driver (odd data) 60 ... Liquid crystal panel 61 ... Switching element 62 ... Pixel 63 ... Common electrode 64, 65 ... Glass substrate 69 ... Counter electrode 67 ... Gate line 68 ... Data line 70, 70 '... Opposing inner surface part of glass substrate

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Satoshi Sekido 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited

Claims (10)

[Claims] 1. A data line, a gate line, and a switching element connected to the gate line and connected to the gate line and driven by a signal of the gate line, on an inner surface of one of the two glass substrates facing each other. In a liquid crystal panel in which a plurality of pixels connected to the switching element are arranged in a matrix, and a common electrode is arranged on the opposite inner surface of the other glass substrate, a group of the common electrodes is arranged. A liquid crystal display device comprising: a liquid crystal panel which is formed by dividing into two groups and is configured so that the voltages applied to the respective groups are applied such that the polarities thereof are opposite to each other. 2. The liquid crystal display device according to claim 1, wherein the common electrode is divided and arranged so that each of the common electrodes can drive a predetermined number of pixels. 3. The liquid crystal display device according to claim 2, wherein the common electrode is arranged in a stripe pattern between pixel groups arranged in the matrix. 4. The liquid crystal display device according to claim 3, wherein the common electrodes formed of adjacent stripes are configured so that the polarities of applied voltages are opposite to each other. 5. A plurality of pixel groups arranged in the data line direction are alternately connected to a common electrode arranged on one side. Item 5. A liquid crystal display device according to items 3 to 4. 6. Each of the common electrodes has pixels arranged on both sides thereof in the data line direction, respectively.
The liquid crystal display device according to claim 5, wherein the gate lines are alternately connected to each other to form a staggered junction form. 7. The data lines according to claim 1, wherein the polarity of the data lines is inverted every other line.
The described liquid crystal display device. 8. The liquid crystal display device according to claim 7, wherein the data line is bent and arranged so that every other gate is connected to another adjacent data line pixel. 9. A liquid crystal display device comprising the liquid crystal panel according to any one of claims 1 to 7 and a driver circuit for driving the liquid crystal panel, wherein the polarities of drive voltages of N data lines and N + 1 data lines. And a line inversion is performed to apply a driving voltage of opposite polarity to the two common electrodes, and at the same time, to invert each polarity for each frame, the liquid crystal display device. . 10. In a liquid crystal display device comprising the liquid crystal panel according to claim 8 and a driver circuit for driving the liquid crystal panel, the polarities of the drive voltages of the N data lines and the N + 1 data lines are reversed. The liquid crystal display device is characterized in that the inversion is performed for each frame, and a drive voltage having an opposite polarity is applied to the two common electrodes, and at the same time, each polarity is inverted for each frame. .