JPH08234235A - Liquid crystal matrix display device - Google Patents

Abstract

PURPOSE: To solve the image quality defect and to improve the reliability by varying the number of connecting terminals of a counter electrode driving circuit to a liquid crystal matrix panel and the number of counter voltage supply points to the counter electrodes in this liquid crystal matrix panel. CONSTITUTION: This liquid crystal matrix display device includes the liquid crystal matrix panel having plural scanning electrodes 3, signal electrodes 7 and switching elements 9, plural pixel electrodes connected to these elements 9 are the counter electrodes 11 arranged to face the pixel electrodes via liquid crystals, scanning electrode driving circuit 4, a signal electrode driving circuit 5 and the counter electrode driving circuit 61. The counter voltage is inputted via plural counter electrode connecting terminals 60 from the counter electrode driving circuit 61. The device is provided with the plural counter voltage supply points 8 exclusive of the points near signal electrodes 7. The counter voltage is inputted through counter voltage distributing lines 80, 81 to the counter voltage supply points 8 and is supplied to the counter electrodes 11. As the result, the parallel connection resistance at the counter voltage supply points is lowered and the waveform distortions of the counter voltage in the panel surface are decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal matrix display device, and more particularly to a high quality and highly reliable display device which can obtain a constant brightness regardless of a display pattern.

[0002]

2. Description of the Related Art An example of the structure of a conventional liquid crystal matrix display device is shown in FIG. The display device includes one substrate 1, the other substrate 2, scan electrodes 3, scan electrode drive circuits 4, signal electrode drive circuits 5, counter voltage supply lines 6, signal electrodes 7, counter voltage supply points 8, switching elements 9, Liquid crystal pixel 10, counter electrode 1
1, a counter voltage connection terminal 60 and a counter electrode drive circuit 61. Although not shown in the drawing, the counter voltage supply point 8 and the counter electrode 11 have the same potential. The one substrate 1 and the other substrate 2 form a liquid crystal matrix panel.

A scanning electrode 3, a signal electrode 7, a counter voltage supply point 8 and a switching element 9 are formed on one substrate 1. As the switching element 9, an amorphous or polycrystalline thin film transistor (TFT) is preferably used. Further, a counter electrode 11 is formed on the other substrate 2. On this substrate, color filters of red, green, blue, etc. are formed as needed.

Scan electrode 3, signal electrode 4 and counter electrode 11
Are driven by a predetermined voltage, which causes the liquid crystal pixel 10
The brightness changes according to the image signal, and the image is displayed on the entire panel.

The counter voltage Vcom is input to the liquid crystal matrix panel via the counter voltage connection terminal 60, but conventionally, the counter voltage is input from four positions, that is, the upper, lower, left and right sides as shown in the figure. The input counter voltage Vcom is the counter voltage supply point 8
Is supplied to the counter electrode 11.

[0006]

The voltage applied to the liquid crystal pixel 10 is the output voltage Vs of the TFT 9 and the voltage Vcom of the counter electrode 11.
Is the difference (= Vs−Vcom), and this value causes liquid crystal pixel 1
The brightness of 0 is determined. The output voltage Vs of the TFT 9 is T
It is almost equal to the voltage of the signal electrode 7 when the FT 9 is turned on.

On the other hand, the counter voltage Vcom, which is the voltage of the counter electrode 11, has only four input points from the counter electrode driving circuit, and the counter electrode has a sheet resistance of several Ω to several tens Ω. Because of the high ITO film used,
The waveform distortion increases in the pixel away from the counter voltage supply point 8. The degree of this waveform distortion increases as the voltage applied to the liquid crystal pixel 10 increases. As previously mentioned,
Since the brightness of the liquid crystal pixel 10 depends on Vs-Vcom, Vcom
When the amount of distortion increases, the voltage applied to the liquid crystal changes, and the brightness of the liquid crystal pixel changes accordingly.

For example, when a signal for varying the brightness of the pixels in only the upper half of the panel is input, the counter voltage Vcom is distorted correspondingly, so that the lower half of the panel, where the brightness should be constant, should be maintained. The brightness of the pixel also changes.

As described above, in the conventional technique, the brightness of the pixel fluctuates because the counter voltage Vcom in the liquid crystal matrix panel is easily distorted according to the display content. For this reason, it is difficult to achieve a liquid crystal matrix panel display device with uniform brightness and high contrast ratio display.

An object of the present invention is to provide a highly reliable liquid crystal matrix display device which solves the problem of poor image quality.

[0011]

Means for Solving the Problems A wiring using at least one kind of electrode material of electrode materials forming a signal electrode or a scanning electrode is formed in a liquid crystal matrix panel, and a counter voltage Vcom input to the liquid crystal matrix panel is input. At least one counter voltage supply point is provided on the side other than near the voltage input and / or on the side other than the voltage input side, and the counter voltage Vcom is supplied to the counter electrode supply point via the wiring. .

[0012]

[Operation] Since the counter voltage Vcom generated in the counter electrode drive circuit is supplied to the counter electrode by the Vcom wiring formed in the liquid crystal matrix panel and the plurality of counter electrode supply points, the parallel connection resistance at the counter voltage supply point And the counter voltage can be supplied to the periphery of the panel, so that the waveform distortion of the counter voltage in the panel surface can be reduced.

[0013]

【Example】

[Embodiment 1] FIG. 1 shows a structural example of a liquid crystal matrix display device according to the present embodiment. Liquid crystal matrix display device,
Substrate 1, Substrate 2, Multiple Scan Electrodes 3, Scan Electrode Driving Circuit 4, Signal Electrode Driving Circuit 5, Opposite Voltage Supply Line 6, Plural Signal Electrodes 7, Opposite Voltage Supply Points 8, TFT 9, Liquid Crystal Pixel 1
0, counter electrode 11, counter voltage connection terminal 60, counter electrode drive circuit 61, counter voltage distribution wirings 80, 81. Although omitted in the drawing, the substrate 1 and the substrate 2 face each other, and liquid crystal is sealed between both substrates to form a liquid crystal matrix panel.

On the substrate 1, scan electrodes 3, signal electrodes 7, counter voltage supply points 8, TFTs 9, counter voltage connection terminals 60 and counter voltage distribution wirings 80, 81 are formed. The counter voltage connection terminal 60 and the counter voltage distribution wirings 80 and 81 are the signal electrodes 7.
Alternatively, it is formed of the same electrode material as the scan electrode 3. The counter voltage supply point 8 is arranged in the peripheral portion of the liquid crystal matrix panel, and further, the counter electrode 11 is formed on the substrate 2. This board has red, green, and
A color filter such as blue is formed.

FIG. 2 is a sectional view taken along line AB in FIG. The counter voltage distribution line 80 and the counter electrode 11 are electrically connected via the counter voltage supply point 8. Further, a plurality of counter voltage supply points 8 are provided on one counter voltage supply line 80.

The scanning electrodes 3 are sequentially scanned by a signal from the scanning electrode drive circuit 4, and a signal voltage corresponding to an image signal is applied to the signal electrodes 7 by a signal from the signal electrode drive circuit 5, whereby the brightness of the liquid crystal pixels 10 is increased. The image is displayed on the entire liquid crystal matrix display panel due to the change in the image.

In the liquid crystal matrix panel, the counter voltage Vcom is supplied from the counter electrode drive circuit 61 via the counter voltage supply line 6 and a plurality of counter electrode connection terminals 60 provided near the signal electrodes.
Has been entered. Further, a plurality of counter voltage supply points 8 are provided other than near the signal electrode, and the counter voltage Vcom is input to the counter electrode supply point 8 via the counter voltage distribution wirings 80 and 81. The input counter voltage Vcom is supplied from the counter voltage supply point 8 to the counter electrode 11.

In this embodiment, the counter electrode 11 is formed of an ITO film having a high sheet resistance of several Ω to several tens Ω, but the liquid crystal matrix panel and the counter electrode drive circuit 61 are used.
Since a plurality of counter voltage supply points 8 can be arranged in the peripheral portion of the liquid crystal matrix panel without increasing the number of connecting lines to and, the waveform distortion of the counter voltage Vcom in the plane of the liquid crystal matrix panel can be reduced. Therefore, it is possible to realize a high-quality liquid crystal matrix display device because it is possible to reduce fluctuations in brightness and to reduce in-plane variations. Further, since it is not necessary to increase the number of connecting lines between the liquid crystal matrix display device and the counter electrode drive circuit 61 to arrange a large number of counter voltage supply points 8, it is possible to prevent a decrease in reliability caused by disconnection or contact failure. In addition, since the number of connecting lines can be reduced, the counter electrode drive circuit 61 and the liquid crystal matrix panel connection configuration mechanism and the manufacturing process can be simplified. Further, in this embodiment, the counter voltage distribution wirings 80 and 81 do not cross the scanning electrodes 3 or the signal electrodes 7, so that it is possible to prevent a display defect due to a short circuit or the like, and it is possible to simplify the manufacturing process. .

[Embodiment 2] FIG. 3 shows a structural example of a liquid crystal matrix display device according to this embodiment. Although omitted in the drawing, the scan electrode drive circuit 4, the signal electrode drive circuit 5, the counter electrode drive circuit 61, the scan electrode 3, the signal electrode 7,
The TFT 9, the liquid crystal pixel 10 and the counter electrode 11 are the same as in the first embodiment.

In the liquid crystal matrix panel, the counter voltage Vcom is supplied from the counter electrode drive circuit 61 via the counter voltage supply line 6 and a plurality of counter electrode connection terminals 60 provided near the signal electrodes.
Has been entered. Further, a plurality of counter voltage supply points 8 are provided other than near the signal electrodes, and counter voltage distribution lines 80, 81, 8 are provided.
The counter voltage Vcom is input to the counter electrode supply point 8 via 2, 83. The input voltage Vcom is supplied to the counter electrode 11 from the counter voltage supply point 8.

In this embodiment, the counter voltage distribution lines 80, 81,
If any one of 82 and 83 is broken, the counter voltage is applied to all the counter voltage supply points 8 by another counter voltage distribution wiring.
Vcom is entered. Therefore, it is possible to prevent a decrease in reliability caused by disconnection. Furthermore, since the resistance between the counter voltage supply point 8 and the counter electrode connection point 60 can be lowered, the waveform distortion of the counter voltage Vcom can be reduced.

[Embodiment 3] FIG. 4 shows a structural example of a liquid crystal matrix display device according to this embodiment. Although omitted in the drawing, the scan electrode drive circuit 4, the signal electrode drive circuit 5, the counter electrode drive circuit 61, the scan electrode 3, the signal electrode 7,
The TFT 9, the liquid crystal pixel 10 and the counter electrode 11 are the same as in the first embodiment.

In the liquid crystal matrix panel, the counter voltage Vcom is supplied from the counter electrode drive circuit 61 via the counter voltage supply line 6 and a plurality of counter electrode connection terminals 60 provided near the signal electrodes.
Has been entered. Further, a plurality of counter voltage supply points 8 are provided other than near the signal electrodes, and counter voltage supply points 80, 81, 8 are provided.
The counter voltage Vcom is input to the counter electrode supply point 8 via 2. The input voltage Vcom is supplied to the counter electrode 11 from the counter voltage supply point 8.

In this embodiment, since the resistance between the counter voltage supply point 8 and the counter voltage connection point 60 can be lowered, the waveform distortion of the counter voltage Vcom can be reduced.

[Embodiment 4] FIG. 5 shows a structural example of a liquid crystal matrix display device according to this embodiment. Although omitted in the drawing, the scan electrode drive circuit 4, the signal electrode drive circuit 5, the counter electrode drive circuit 61, the scan electrode 3, the signal electrode 7,
The TFT 9, the liquid crystal pixel 10 and the counter electrode 11 are the same as in the first embodiment.

In the liquid crystal matrix panel, the counter voltage Vcom is supplied from the counter electrode drive circuit 61 via the counter voltage supply line 6 and a plurality of counter electrode connection terminals 60 provided near the signal electrodes.
Has been entered. Further, a plurality of counter voltage supply points 8 are provided other than near the signal electrodes, and counter voltage distribution lines 80, 81, 8 are provided.
The counter voltage Vcom is input to the counter electrode supply point 8 via 3. The input voltage Vcom is supplied to the counter electrode 11 from the counter voltage supply point 8.

In this embodiment, since the resistance between the counter voltage supply point 8 and the counter voltage connection point 60 can be lowered, the waveform distortion of the counter voltage Vcom can be reduced.

[Embodiments 5 to 8] FIGS. 6 to 9 show configuration examples of a liquid crystal matrix display device in which the counter electrode connection terminals 60 according to the present embodiment are provided near the scanning electrodes. Although omitted in the drawing, the scanning electrode driving circuit 4, the signal electrode driving circuit 5, the counter electrode driving circuit 61, the scanning electrode 3, the signal electrode 7, the TFT 9, the liquid crystal pixel 10, and the counter electrode 11 are the same as those in the first embodiment. It is the same.

In the liquid crystal matrix panel, the counter voltage Vcom is supplied from the counter electrode drive circuit 61 via the counter voltage supply line 6 and a plurality of counter electrode connection terminals 60 provided near the scan electrodes.
Has been entered. Further, a plurality of counter voltage supply points 8 are provided other than near the signal electrodes, and counter voltage distribution lines 80, 81, 8 are provided.
The counter voltage Vcom is input to the counter electrode supply point 8 via at least one of 2, 83. Input voltage
Vcom is supplied to the counter electrode 11 from the counter voltage supply point 8.

In the present embodiment, in the case of a liquid crystal matrix panel used for a personal computer or the like, the pitch of arranging the scanning electrodes 3 is larger than the pitch of arranging the signal electrodes 7, so that it is possible to prevent a display defect due to a short circuit. The other effects of Examples 5 to 8 are the same as the effects of Examples 1 to 4.

[Embodiments 9 to 11] FIGS. 10 to 12 show the construction of a liquid crystal matrix display device in which the counter electrode connection terminals 60 according to the present embodiment are provided near the scanning electrodes and near the signal electrodes. Although omitted in the drawing, the scanning electrode driving circuit 4, the signal electrode driving circuit 5, the counter electrode driving circuit 61,
The scanning electrode 3, the signal electrode 7, the TFT 9, the liquid crystal pixel 10 and the counter electrode 11 are the same as those in the first embodiment.

The counter voltage Vcom is input to the liquid crystal matrix panel from the counter electrode drive circuit 61 via the counter voltage supply line 6 and a plurality of counter electrode connection terminals 60 provided near the scan electrodes and near the signal electrodes. There is. Further, a plurality of counter voltage supply points 8 are provided other than near the signal electrodes, and the counter electrode supply points 8 are provided via the counter voltage distribution wirings 80, 81, 82, 83.
Opposing voltage Vcom is input to. Input counter voltage
Vcom is supplied to the counter electrode 11 from the counter voltage supply point 8.

In the present embodiment, since a plurality of counter electrode connection terminals 60 are provided both near the scanning electrodes and near the signal electrodes, the resistance between the counter electrode common point 8 and the counter electrode connection terminals 60 can be further reduced. Therefore, the waveform distortion of the counter voltage Vcom can be further reduced. Further, the counter voltage Vcom input from the plurality of counter electrode connection terminals 60 provided near the scan electrodes
When the counter voltage distribution wiring supplying the counter voltage is broken, the counter voltage distribution wiring supplying the counter voltage Vcom input from the counter electrode connecting terminal 60 provided near the signal electrode is used to supply a plurality of counter electrode supply points 8 Opposing voltage Vcom is input to. Note that the opposite case has the same effect.

[0034]

According to the present invention, since the waveform distortion of the counter voltage in the liquid crystal matrix panel can be reduced, the fluctuation of the brightness of the image display can be reduced, and the in-plane variation can be reduced, so that a high quality display device can be obtained. realizable.

Further, even if the counter voltage supply points are increased, it is not necessary to increase the number of connecting lines between the liquid crystal matrix panel and the counter electrode driving circuit, so that it is possible to prevent the reliability from being lowered due to disconnection or contact failure. Further, since the number of connecting lines can be reduced, it is possible to simplify the drive circuit and the panel connection configuration mechanism and the manufacturing process.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating a configuration example of a liquid crystal matrix display device according to a first embodiment.

FIG. 2 is a cross-sectional view taken along line AB of the liquid crystal matrix display device of Example 1.

FIG. 3 is an explanatory diagram showing a configuration example of a liquid crystal matrix display device of Example 2.

FIG. 4 is an explanatory diagram illustrating a configuration example of a liquid crystal matrix display device according to a third embodiment.

FIG. 5 is an explanatory diagram showing a configuration example of a liquid crystal matrix display device of Example 4.

FIG. 6 is an explanatory diagram showing a configuration example of a liquid crystal matrix display device of Example 5.

FIG. 7 is an explanatory diagram showing a configuration example of a liquid crystal matrix display device of Example 6.

FIG. 8 is an explanatory diagram showing a configuration example of a liquid crystal matrix display device of Example 7.

FIG. 9 is an explanatory diagram showing a configuration example of a liquid crystal matrix display device of Example 8.

FIG. 10 is an explanatory diagram showing a configuration example of a liquid crystal matrix display device of Example 9.

FIG. 11 is an explanatory diagram showing a configuration example of a liquid crystal matrix display device of Example 10.

FIG. 12 is an explanatory diagram showing a configuration example of a liquid crystal matrix display device of Example 11.

FIG. 13 is an explanatory diagram showing a configuration example of a conventional liquid crystal matrix display device.

[Explanation of symbols]

1, 2 ... substrate, 3 ... scan electrode, 4 ... scan electrode drive circuit,
5 ... Signal electrode drive circuit, 6 ... Counter voltage supply line, 7 ... Signal electrode, 8 ... Counter voltage supply point, 9 ... TFT, 10 ... Liquid crystal pixel, 11 ... Counter electrode, 60 ... Counter voltage connection terminal, 61 ...
Counter electrode drive circuit, 80, 81 ... Wiring for counter voltage.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiko Suzuki 3300 Hayano, Mobara-shi, Chiba Hitachi, Ltd. Electronic Device Division (72) Masataka Natori 3300 Hayano, Mobara-shi, Chiba Hitachi, Ltd. Electronic Device Business Department

Claims (5)

[Claims] 1. A plurality of scanning electrodes, a plurality of signal electrodes, a plurality of switching elements, a plurality of pixel electrodes connected to the switching elements, and a counter electrode arranged so as to face the pixel electrodes via a liquid crystal. An image is displayed on the liquid crystal matrix panel including a liquid crystal matrix panel having the same, a scan electrode drive circuit for driving the scan electrodes, a signal electrode drive circuit for driving the signal electrodes, and a counter electrode drive circuit for driving the counter electrodes. In a liquid crystal matrix display device for displaying, the number of connection terminals between the counter electrode drive circuit and the liquid crystal matrix panel is different from the number of counter voltage supply points to the counter electrode in the liquid crystal matrix panel. apparatus. 2. The liquid crystal matrix display device according to claim 1, wherein the number of connection terminals between the counter drive circuit and the liquid crystal matrix panel is smaller than the number of counter voltage supply points in the liquid crystal matrix panel. 3. The liquid crystal matrix display device according to claim 1, wherein the counter voltage connection terminal is provided near the scanning electrode and / or near the signal electrode. 4. A plurality of scanning electrodes, a plurality of signal electrodes, a plurality of switching elements, a plurality of pixel electrodes connected to the switching elements, and a counter electrode arranged so as to face the pixel electrodes via a liquid crystal. An image is displayed on the liquid crystal matrix panel including a liquid crystal matrix panel having the same, a scan electrode drive circuit for driving the scan electrodes, a signal electrode drive circuit for driving the signal electrodes, and a counter electrode drive circuit for driving the counter electrodes. In the liquid crystal matrix display device for displaying, at least one counter voltage supply point to the counter electrode is provided in the liquid crystal matrix panel on a side other than the side where the counter electrode drive circuit and the liquid crystal matrix panel are connected. Characteristic liquid crystal matrix display device. 5. The liquid crystal matrix display device according to claim 4, wherein the counter voltage is supplied to the counter voltage supply point by at least one kind of electrode material forming the signal electrode or the scan electrode.