JPH08297300A - Color liquid crystal display device - Google Patents

Abstract

PURPOSE: To discriminate what color the defect of a display picture element corresponds to among R, G and B at a stage before liquid crystal displaying by applying shape for discrimination in a color liquid crystal display device. CONSTITUTION: Picture element discriminating function parts 102A and 102B are installed on a gate bus line 103 in order to discriminate what color of R, G and B prepared on a common electrode side arranged to be opposed to picture element electrodes 101A, 101B and 101C constituting the display picture element 100 the defect corresponds to. Thus, the defective display picture element is specified and a fault occurring at the time of liquid crystal displaying is known by analogy before occurring. Then, the defect is found out in an early stage, working efficiency is improved and the efficiency of taking measures such as mending is made high.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color liquid crystal display device, and more particularly to a liquid crystal display device for active matrix driving type color display.

[0002]

2. Description of the Related Art FIG. 5 is a partial schematic view of a liquid crystal display device controlled by a conventional active matrix driving method.
It is a top view of the thin film transistor array (TFT) substrate side. The liquid crystal display pixel 300 is formed by arranging the pixel electrodes 301 in a matrix. A charge sent from the source bus line 304 is supplied to each pixel electrode by a signal sent from the gate bus line 303. If the charge is not normally supplied to each pixel electrode due to some trouble, the liquid crystal display device becomes defective. In such a device, early detection of a defect and identification of the location of the defect are essential.

Therefore, the shape of the pixel electrode is changed every other column like the pixel electrode 301A and the pixel electrode 301B, and the pixel electrode 301A supplies electric charge from a source bus line connected to an upper drive circuit (not shown). The pixel electrode 301
B uses a charge supplied from a source bus line connected to a lower drive circuit (not shown) to identify the top and bottom of the source bus line 304 (Japanese Patent Application No. 5-26).
5406), or a series of serial numbers 402 such as 42, 43 ... As shown in FIG. 6 are formed in the pixel electrode 401 by a transparent electrode punching pattern and a defective portion is identified by contrast (JP-A-2-140721). and so on. Further, as shown in FIG. 7, the identification number 5 such as 1, 2, 3, ... Is not assigned to the source bus line 504, not inside the pixel electrode.
02 is used as a guide for specifying the position (Actual number 60-1)
50522).

[0004]

In the color liquid crystal display device, the color of the display pixel is composed of three colors of R (red), G (green) and B (blue). Defects that occur in units (particularly those with green point defects) are screened out by inspection in the panel or module state. In the above-mentioned conventional color liquid crystal display device, a defective portion found by inspection in a panel or module state can be accurately traced during analysis and investigation. However, since it is impossible to determine which color (R, G, B) required for color display corresponds to the defective portion found in the manufacturing process of the thin film transistor array substrate, it is not possible to judge pass / fail in this process and the subsequent process It is allowed to leak defects.

[0005]

In order to solve the above problems, the color liquid crystal display device according to the present invention is characterized in that the shape of each pixel electrode is different corresponding to each color required for color display. Alternatively, the shape of the gate bus line in contact with each display pixel is different depending on each color required for color display, or the shape of the storage capacitor in contact with each display pixel is different for each color display. It is characterized in that it differs depending on the color. Alternatively, it is characterized in that a characteristic shape (for example, letters such as R, G, B, etc.) corresponding to each color required for color display is left in each pixel electrode by a pattern of a transparent electrode.

[0006]

The present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic plan view of a TFT substrate showing a first embodiment of the present invention. In the liquid crystal display device of this embodiment, ITO (indium tin oxide) is provided in the source bus line 104 and the gate bus line 103 which are formed on the glass substrate at equal intervals in the vertical and horizontal directions, and the region surrounded by the source bus line 104 and the gate bus line 103.
The liquid crystal display pixels 100 are arranged in a matrix by arranging the pixel electrodes 101 having transparent electrodes. FIG. 2 is a sectional view thereof. Here, when the pixel electrode is extended and formed on the gate bus line, the pixel electrode has a capacitor sandwiching the insulating film between the pixel electrode and the gate bus line, and the capacitor serves as a storage capacitor. Therefore, in general, the term "storage capacitor" refers to the overlapping portion itself of the gate bus line and the pixel electrode. In that case, the overlapping pixel electrodes (a part of the pixel electrodes) are shielded by the gate bus line regardless of the operation thereof, and thus do not directly contribute to the display.

Each of the pixel electrodes has a thin film transistor (TFT) 105 for switching, and performs a display operation. If a defect occurs in the TFT or the pixel electrode, the corresponding liquid crystal display unit does not operate normally and the liquid crystal display becomes defective. However, since an actual display device is an aggregate of a large number of liquid crystal displays, the fact that one of them has a defect does not mean that the liquid crystal display device itself is defective. Particularly importantly, in the case of a liquid crystal display device intended for color display, the distinction between good and defective is different depending on the color corresponding to the defective liquid crystal display section. Therefore, in the case of a liquid crystal display device intended for color display, it is important to obtain information on the defective portion in advance. However, the liquid crystal display device is roughly divided into three in the manufacturing process, and the manufacturing of the substrate on the TFT side (hereinafter, TFT substrate) for actually performing the display operation,
The TFT substrate and the substrate on the opposite side having the color layer (hereinafter, the opposite substrate) are overlapped with the liquid crystal in between, the process proceeds in the order of modularization, and the actual display becomes possible after the step is completed, Defects cannot usually be identified until they are displayed.

Therefore, as a method for detecting defects at the stage of the TFT substrate in advance, an abnormal pattern can be detected by using an optical system. However, as a result, even if the defective portion can be identified, it is difficult to determine which color of R, G, and B of the counter substrate the display pixels arranged in the matrix correspond to. Therefore, the pixel electrodes 101A and 1A that are distinguished by changing the shape of the storage capacitor of the pixel identification function unit into a quadrangle 102A and a triangle 102B.
When 01B and 101C are made to correspond to the respective stripe-arranged colors R, G, and B prepared on the common electrode side which is arranged opposite to each other, the difference due to the quadrangle 102A, the triangle 102B as the pixel identification function part, or the presence or absence thereof. This makes it possible to specify which color of R, G, and B each display pixel corresponds to.

Further, in FIG. 1, it is assumed that the colors of R, G, and B prepared on the side of the common electrode opposed to each other are arranged in stripes, but the second embodiment of the present invention shown in FIG. Even when the colors of R, G, and B are in the delta arrangement as in the above embodiment, the discrimination is possible in the same manner, and the case of the delta arrangement exerts a more useful effect.

In the above embodiments, the thin film transistor, which is a non-linear element, drives the liquid crystal display pixels arranged in a matrix. However, the matrix structure for color display is used in other driving methods. The present invention can be applied to all of the liquid crystal display devices that the user has.
Needless to say, the present invention is not limited to the illustrated embodiments. Further, the function according to the image structure is not limited to the above-mentioned embodiment, and the difference in the shape of the gate bus line in contact with the pixel electrode or the difference in the shape of the pixel electrode itself has the same effect. Is natural.

FIG. 4 is a schematic plan view showing a third embodiment of the present invention. In the liquid crystal display device of this embodiment, a source bus line 204 and a gate bus line 203 are provided on a glass substrate at regular intervals in a vertical and horizontal grid pattern, and a transparent electrode of ITO (indium tin oxide) is provided in a region surrounded by the source bus line 204 and the gate bus line 203. Liquid crystal display pixel 200 including a pixel electrode 201 having
Are arranged in a matrix. The pixel electrode 201 has a switching TFT 205 and controls a display operation. If a defect occurs in the TFT 205 or the pixel electrode 201, the corresponding display pixel does not operate normally and the liquid crystal display device becomes defective.

However, just because one of the display pixels is defective does not mean that the liquid crystal display device is defective. Particularly in the case of a liquid crystal display device intended for color display, the degree of failure varies depending on the corresponding color of the defective display pixel. Therefore, it is important to know the display pixel defect in advance. Therefore, ITO of the transparent electrode
The pixel electrodes 201 are formed of (indium tin oxide), and at the same time, the respective colors R and G prepared on the common electrode side opposed to each other by the photolithography method.
-Blank pattern 2 which is a pixel identification function corresponding to B
By forming 02A, 202B, and 202C, it is possible to specify which color of R, G, and B each display pixel corresponds to.

In the example shown in FIG. 4, it is assumed that the colors of R, G and B prepared on the side of the common electrode opposed to each other are in a delta arrangement, but the colors of R, G and B are stripes. It goes without saying that the same effect can be obtained in the case of arrangement.

In the above-mentioned embodiment, the thin film transistor which is a non-linear element drives the liquid crystal display pixels arranged in matrix, but other driving methods have a matrix structure for the purpose of color display. The present invention can be applied to all liquid crystal display devices. Needless to say, the present invention is not limited to the illustrated embodiments.

[0015]

As described above, according to the present invention,
By using a method of identifying a large number of liquid crystal display pixels arranged in a matrix corresponding to the respective colors of R, G, and B prepared on the common electrode side which is arranged to face each other, a defect generated in a certain display pixel can be displayed. Needless to say, it is possible to know which color of R, G, and B is the defect corresponding to the state of the thin film transistor array substrate, and it is possible to detect defects early, improve work efficiency, and improve the efficiency of countermeasures such as repairs. It will be possible. Furthermore, R
・ The defect color differs depending on which color of G, B, so even though I knew it was a defect, I could not identify the color of R, G, B, so I had to proceed to the liquid crystal display state. In the opposite case, waste is also improved, such as rejecting a product that may have been good because the colors R, G, and B could not be specified.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a first embodiment according to the present invention.

FIG. 2 is a schematic sectional view of the first embodiment.

FIG. 3 is a schematic plan view of the second embodiment of the present invention.

FIG. 4 is a schematic plan view showing a third embodiment according to the present invention.

FIG. 5 is a schematic plan view of the prior art.

FIG. 6 is another schematic plan view of the prior art.

FIG. 7 is yet another overall schematic diagram of the prior art.

[Explanation of symbols]

100, 200, 300, 400 Liquid crystal display pixel 101, 201, 301, 401 Pixel electrode 102, 202, 402, 502 Pixel identification function part 103, 203, 303, 403 Gate bus line 104, 204, 304, 404, 504 Source Bus line 105, 205, 305, 405 TF 106 Common electrode 107 Liquid crystal 500 Liquid crystal display unit

Claims (3)

[Claims] 1. A color liquid crystal display device controlled by an active matrix driving method, wherein a shape of a gate bus line in contact with each display pixel is different corresponding to each color required for color display. Display device. 2. A color liquid crystal display device controlled by an active matrix driving method, wherein a shape of a storage capacitor in contact with each display pixel is different corresponding to each color required for color display. apparatus. 3. In a color liquid crystal display device controlled by an active matrix driving method, a characteristic shape corresponding to each color required for color display is left in each display pixel electrode by a transparent electrode punching pattern. Characteristic color liquid crystal display device.