JPH08110509A - Liquid crystal display device and its inspection method - Google Patents

Abstract

PURPOSE: To make it possible easily inspect lighting by each color. CONSTITUTION: The common electrodes 24 of a liquid crystal display device consists of common electrodes 24R for red, common electrodes 24G for green and common electrodes 24B for blue formed in correspondence to respective color filters 12R, 12G, 12B of red, green and blue. Since respective common electrodes 24R, 24G, 24B for the respective colors in such a case are connected by connecting wires for respective colors, only the common electrodes 24R for red are held at a common electrode potential by connecting probes to the ends of, for example, the connecting wirings for red. There is, therefore, no need for selectively impressing driving voltage on the respective terminals of gate lines 7 and drain lines 8 like heretofore and the simultaneous impression of the driving voltage at the respective terminals of the gate lines 7 and the drain lines 8 suffices at the time of inspection by lighting only the pixel in accordance with the red filter 12R. Consequently, the lighting inspection per color is easily carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix type liquid crystal display device and its inspection method.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional active matrix type liquid crystal display device. In this liquid crystal display device, a display drive panel 1 and a common electrode panel 2 arranged on the display drive panel 1 are attached to each other via a seal material 3, and liquid crystal (not shown) is sealed inside the seal material 3 to perform display drive. Polarizing plates 4 and 5 are provided on the lower surface of the panel 1 and the upper surface of the common electrode panel 2. In the display drive panel 1, gate lines (scanning electrodes) 7 and drain lines (signal electrodes) 8 are formed in a grid pattern on the upper surface of a lower transparent substrate 6 made of glass or the like, and thin film transistors are formed in the vicinity of intersections of these. (Display driving element) 9 is formed, and a pixel electrode 10 which is slightly smaller than this is formed in the remaining portion of each lattice except the thin film transistor 9, and the gate line 7, the drain line 8, the thin film transistor 9, and the pixel electrode are formed. A lower alignment film (not shown) is provided on the upper surface of the lower transparent substrate 6 including 10. On the other hand, in the common electrode panel 2,
A red filter 12 corresponding to each pixel electrode 10 of the display drive panel 1 is formed on the lower surface of an upper transparent substrate 11 made of glass or the like.
A color filter 12 including R, a green filter 12G, and a blue filter 12B is provided, a common electrode 13 made of ITO or the like is provided on the lower surface of the color filter 12 through an intermediate film (not shown), and a lower surface of the common electrode 13 is provided. Is provided with an upper alignment film (not shown). Note that the arrangement of the color filters 12 as shown in FIG. 4 is called a mosaic type, but there are other arrangements such as a triangle type and a stripe type.

When the common electrode 13 is set to a predetermined common electrode potential (V _COM ) and a predetermined driving voltage is applied to the gate line 7 and the drain line 8, the thin film transistor 9 is driven. That is, for example, in the case of the N-channel thin film transistor 9, when the gate voltage (V _G ) becomes high level compared to the common electrode potential, the thin film transistor 9 is turned on and the pixel electrode potential (V
_P ) becomes equal to the potential (V _ID ) of the drain line 8.
On the other hand, when the gate voltage becomes low level compared with the common electrode potential, the thin film transistor 9 is turned off and the signal written in the liquid crystal capacitance or the like is held.

By the way, in such a liquid crystal display device,
It is important that there is no variation in chromaticity or illuminance of each pixel. Therefore, each color is turned on, and whether or not there is variation in chromaticity, illuminance, etc. for each pixel is visually inspected from the hue, color tone, contrast, etc.
For example, in the case of inspecting for red color, only the pixels corresponding to the red film 12R are turned on, and it is inspected for each pixel whether or not there are variations in chromaticity, illuminance, and the like. In this case, the gate line driving circuit and the drain line driving circuit are electrically connected to the respective terminals of the gate line 7 and the drain line 8 via the probe, respectively, and the common electrode 13 is set to the common electrode potential via the probe. It is necessary to selectively apply a positive bias voltage for turning on 9 or a negative bias voltage for turning off 9 to turn on only the pixel corresponding to the red filter 12R.

[0005]

However, in the conventional method for inspecting such a liquid crystal display device, for example, even when only the pixel corresponding to the red filter 12R is illuminated and inspected, the gate line 7 and the drain line 8 are used. Since it is necessary to electrically connect the gate line drive circuit and the drain line drive circuit to each of the terminals through the probe respectively, the inspection time becomes long, the inspection device becomes expensive, and the inspection device installation time is long. However, there is a problem that the lighting inspection cannot be easily performed for each color due to the necessity of lighting. In particular, when the pitch of the gate line 7 and the drain line 8 becomes finer, it becomes difficult to form a probe corresponding to the pitch, and this tendency becomes even stronger. An object of the present invention is to provide a liquid crystal display device and a method for inspecting the same, which can easily perform a lighting inspection for each color.

[0006]

According to the first aspect of the present invention,
One of a display drive panel provided with pixel electrodes and display drive elements and a common electrode panel provided with common electrodes is provided with red, green, and blue color filters corresponding to the pixel electrodes. , In a liquid crystal display device in which liquid crystal is sealed between both panels, the common electrode is a common electrode for each color provided corresponding to each color filter, and the common electrode for each color corresponding to the color filter of the same color is for each color. They are connected to each other by connection wiring. Claim 2
According to the invention described above, one of a display drive panel provided with a pixel electrode and a display drive element and a common electrode panel provided with a common electrode is provided with red, green and blue corresponding to the pixel electrode. A method for inspecting a liquid crystal display device in which a voltage is applied between a display drive panel and a common electrode panel of a liquid crystal display device in which filters for each color are provided and liquid crystal is sealed between both panels to perform lighting inspection for each color. In, the common electrode consists of the common electrode for each color provided corresponding to each color filter, the common electrode for each color corresponding to the color filter of the same color is connected by the connection wiring for each color, respectively, to the common electrode for each predetermined color. The inspection is performed by applying a drive signal through the connection wiring for each color.

[0007]

According to the present invention, the common electrode is composed of the common electrode for each color provided corresponding to each color filter, and the common electrodes for each color corresponding to the color filters of the same color are connected by the connection wiring for each color. Therefore, as described in claim 2, by applying a drive signal to the predetermined common electrode for each color through the connection wiring for each color and inspecting, only the common electrode for each color corresponding to the predetermined color filter is detected. The common electrode potential can be set, and the common electrodes for each color corresponding to the other color filters can be set to a potential at which the liquid crystal does not operate. Therefore, when only a pixel corresponding to a predetermined color filter is illuminated and inspected, it is not necessary to selectively apply a drive voltage to each terminal of the gate line and the drain line as in the conventional case, and A drive voltage may be applied to each terminal collectively. As a result, the lighting inspection for each color can be easily performed.

[0008]

1 shows a liquid crystal display device according to an embodiment of the present invention. In this figure, parts having the same names as in FIG. 4 are assigned the same reference numerals and explanations thereof are omitted as appropriate. In this liquid crystal display device, the display drive panel 1 and the common electrode panel 2 arranged on the display drive panel 1 are attached to each other with the seal material 3 interposed therebetween, and the liquid crystal 21 is sealed inside the seal material 3 so that the lower surface of the display drive panel 1 is sealed. Polarizing plates 4 and 5 are provided on the upper surface of the common electrode panel 2.

The display drive panel 1 has a lower transparent substrate 6 made of glass or the like. A gate line 7, a drain line 8, a thin film transistor 9, a pixel electrode 10 and the like are formed on the upper surface of the lower transparent substrate 6 (see FIG. 4). A lower alignment film 22 made of polyimide or the like is provided on the upper surface of the lower transparent substrate 6 including the gate line 7, the drain line 8, the thin film transistor 9, and the pixel electrode 10. On the other hand, the common electrode panel 2 includes an upper transparent substrate 11 made of glass or the like. On the lower surface of the upper transparent substrate 11, a color filter 1 including a red filter 12R, a green filter 12G, and a blue filter 12B corresponding to each pixel electrode 10 of the display drive panel 1.
2 are provided. On the lower surface of the color filter 12,
A common electrode 24 made of ITO or the like is provided via an intermediate film 23. The common electrode 24 will be described in detail later, but the red, green, and blue color filters 12R, 12G, and 12B.
Common electrodes 24R, 24G for each color provided corresponding to
It consists of 24B. An upper alignment film 25 made of polyimide or the like is provided on the lower surface of the common electrode 24.

FIG. 2 is a plan view of the common electrode 24. In this figure, R indicates the red common electrode 24R, G indicates the green common electrode 24G, and B indicates the blue common electrode 24B. Common electrode 24R for each color, 2
4G and 24B are red, green, and blue color filters 12R, 1
It is arranged in a mosaic pattern corresponding to 2G and 12B.
The red common electrodes 24R are sequentially connected by the red connection wiring 26R. Red connection terminals 27R are provided at both ends of the red connection wiring 26R. Each green common electrode 24G is connected to the green connection wiring 2
It is sequentially connected by 6G. Green connection terminals 27G are provided at both ends of the green connection wiring 26G. The blue common electrodes 24B are sequentially connected by the blue connection wiring 26B. Blue connection terminals 27B are provided at both ends of the blue connection wiring 26B.

Next, a method of inspecting such a liquid crystal display device will be described. First, the monochromatic color filters 12R, 1
A case will be described in which only the pixels corresponding to 2G and 12B are lit and inspected. For example, when only the pixel corresponding to the red filter 12R is turned on, the potential of each red common electrode 24R is set to the common electrode potential via the red connection wiring 26R, and each green common electrode 24G and each blue common electrode are connected. A gate voltage is applied to the electrode 24B via the green connection wiring 26R and the blue connection wiring 26B so that the liquid crystal does not operate, and the drive voltage is collectively applied to each gate line 7 and drain line 8. The same applies to other cases. Next, a combination of two predetermined colors, that is, a combination of the red filter 12R and the green filter 12G, a combination of the red filter 12R and the blue filter 12B, or a green filter 12G and the blue filter 12 is used.
A case of simultaneously lighting the pixels corresponding to the combination with B will be described. For example, when the pixels corresponding to the red filter 12R and the green filter 12G are turned on at the same time, the potentials of the red common electrode 24R and the green common electrode 24G are supplied via the red connection wiring 26R and the green connection wiring 26G. A common electrode potential is applied, and a gate voltage is applied to each blue common electrode 24B via a blue connection wiring 26B so that liquid crystal does not operate, and each gate line 7 is connected.
The drive voltage is applied to the drain line 8 at once. The same applies to other cases. Further, when the pixels corresponding to all the color filters 12R, 12G, and 12B are turned on at the same time, the potentials of the red common electrode 24R, the green common electrode 24G, and the blue common electrode 24B are set to the respective color connection wirings 26R. , 26G, 26B to a common electrode potential, and a drive voltage is applied to each gate line 7 and drain line 8 collectively.

As described above, the common electrode 24 includes the common electrodes 24R, 24G, 24B for the respective colors provided corresponding to the respective color filters 12R, 12G, 12B, and corresponds to the color filters 12R, 12G, 12B of the same color. The common electrodes 24R, 24G, 24B for the respective colors are the connection wirings 26R, 2 for the respective colors.
Since they are respectively connected by 6G and 26B, for example, by bringing the probe into contact with the red connection terminal 27R provided at the end of the red connection wiring 26R, only the red common electrode 24R corresponding to the red filter 12R is formed. It becomes the common electrode potential. Therefore, when only the pixel corresponding to the red filter 12R is illuminated and inspected, it is not necessary to selectively apply the drive voltage to each terminal of the gate line 7 and the drain line 8 as in the conventional case, and the gate line 7 and the drain The drive voltage may be collectively applied to each terminal of the line 8. As a result, the lighting inspection for each color can be easily performed.

FIG. 3 shows a liquid crystal display device according to another embodiment of the present invention. In this figure, the same reference numerals are given to the same names as those in FIG. 1, and the description thereof will be omitted as appropriate. In this liquid crystal display device, a color filter 12 is provided on the display drive panel 1 side. That is, in the display drive panel 1, the red filter 12R, the green filter 12G, and the blue filter 12B are provided on the upper surface of the lower transparent substrate 6.
Is provided, and the gate line 7, the drain line 8, the thin film transistor 9, and the pixel electrode 1 are provided on the upper surface of the color filter 12 via the intermediate film 23.
0 is provided, and the lower alignment film 22 is provided on the upper surface thereof. On the other hand, the common electrode panel 2 includes common electrodes 24R, 24G, 24B for respective colors corresponding to the red, green, and blue color filters 12R, 12G, 12B of the display drive panel 1 on the lower surface of the upper transparent substrate 11. An electrode 24 is provided, and an upper alignment film 25 is provided on the lower surface of the common electrode 24. As described above, the color filter 12 may be provided on one of the display drive panel 1 and the common electrode panel 2.

In the above embodiment, the gate voltage is applied to the common electrodes for each color corresponding to the pixels that are not turned on, for example, the common electrode 24G for green and the common electrode 24B for blue, but the invention is not limited to this. A voltage that does not drive the liquid crystal may be applied. Further, in the above embodiment, the red common electrode 24R is connected by the red connection wiring 26R, the green common electrode 24G is connected by the green connection wiring 26G, and the blue common electrode 24B is connected by the blue connection wiring 26B. However,
The present invention is not limited to this. For example, when performing a lighting inspection only on the pixels corresponding to the red filter 12R, only the red common electrode 24R is connected by the red connection wiring 26R,
The remaining green common electrode 24G and blue common electrode 24
B may be connected by the same common connection wiring. Further, in the above embodiment, the connection terminals 27R, 27G, 27B for each color are provided at both ends of the connection wirings 26R, 26G, 26B for each color, but the present invention is not limited to this, and the connection wirings 26R, 26 for each color are provided.
It may be provided on either one of both ends of G and 26B. However, if the connection terminals 27R, 27G, 27B for each color are provided at both ends of the connection wirings 26R, 26G, 26B for each color, the connection wirings 26R, 26G, 26B for each color and the common electrodes 24R, 24G, 24B for each color are short-circuited. Can be inspected. Further, although the thin film transistor 9 is used as the display driving element in the above-mentioned embodiment, the invention is not limited to this, and may be, for example, an MIM (metal insulator metal) element.

[0015]

As described above, according to the present invention, the common electrode is composed of the common electrode for each color provided corresponding to each color filter, and the common electrode for each color corresponding to the color filter of the same color is each color. Since they are respectively connected by the connection wiring for each color, as described in claim 2, by applying a drive signal to the common electrode for each predetermined color through the connection wiring for each color and inspecting, a predetermined color filter can be obtained. Only the corresponding common electrode for each color can be set to the common electrode potential, and the common electrode for each color corresponding to another color filter can be set to the potential at which the liquid crystal does not operate. Therefore, when only a pixel corresponding to a predetermined color filter is illuminated and inspected, it is not necessary to selectively apply a drive voltage to each terminal of the gate line and the drain line as in the conventional case, and the gate line and the drain line are not selectively applied. A drive voltage may be applied to each terminal collectively. As a result, the lighting inspection for each color can be easily performed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a common electrode in the liquid crystal display device.

FIG. 3 is a sectional view showing a liquid crystal display device according to another embodiment of the present invention.

FIG. 4 is an exploded perspective view showing a conventional liquid crystal display device.

[Explanation of symbols]

 1 Display Driving Panel 2 Common Electrode Panel 7 Gate Line 8 Drain Line 9 Thin Film Transistor (Display Driving Element) 10 Pixel Electrode 12 Color Filter 24 Common Electrode 26R, 26G, 26B Connection Wiring 27R, 27G, 27B Connection Terminal

Claims (3)

[Claims] 1. A display driving panel provided with a pixel electrode and a display driving element, and a common electrode panel provided with a common electrode, and a red electrode, a green electrode, a blue electrode corresponding to the pixel electrode, In the liquid crystal display device in which each color filter is provided and liquid crystal is sealed between the both panels, the common electrode includes a common electrode for each color provided corresponding to each color filter, and the same color filter 2. The liquid crystal display device, wherein the common electrodes for each color corresponding to are connected to each other by connection wirings for each color. 2. One of a display drive panel provided with a pixel electrode and a display drive element and a common electrode panel provided with a common electrode is provided with red, green, blue corresponding to the pixel electrode. , A liquid crystal display in which a lighting test is performed for each color by applying a voltage between the display drive panel and the common electrode panel of a liquid crystal display device in which liquid crystals are sealed between the both panels. In the method of inspecting an apparatus, the common electrode includes a common electrode for each color provided corresponding to each color filter, and the common electrodes for each color corresponding to the color filters of the same color are respectively connected by connection wirings for each color. A method for inspecting a liquid crystal display device, which comprises inspecting by applying a drive signal to a predetermined common electrode for each color through the connection wiring for each color. 3. The common electrode for each color corresponding to each color filter of red, green, and blue is connected by the connection wiring for each color, and a terminal portion is provided at at least one end of each connection wiring for each color. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is provided.