JP2710582B2 - Color liquid crystal display - Google Patents

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, and more particularly to a liquid crystal display for an 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 on 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. Each pixel electrode is supplied with a charge from a source bus line 304 by a signal sent from a gate bus line 303. If the supply of electric charge is not performed normally due to some trouble to each pixel electrode, the liquid crystal display device becomes defective. In such a device, early detection of a defect and identification of the position where the defect has occurred are essential.

Therefore, the shape of the pixel electrode is changed every other column to a pixel electrode 301A and a pixel electrode 301B, and the pixel electrode 301A supplies charges from a source bus line connected to an upper driving circuit (not shown). And the pixel electrode 301
B uses a method in which electric charges are supplied from a source bus line connected to a lower drive circuit (not shown), and specifies the upper and lower sides of the source bus line 304 (Japanese Patent Application No. Hei 5-26).
5406) or a method of forming a series of serial numbers 402 such as 42, 43... In the pixel electrode 401 by using a transparent electrode punching pattern as shown in FIG. 6 and identifying a defective portion by contrast (Japanese Unexamined Patent Publication No. 2-140721). and so on. Also, as shown in FIG. 7, the source bus line 504 is not provided in the pixel electrode but in the identification number 5,
02 as a guide for specifying the position
50522).

[0004]

In the color liquid crystal display device, the colors of the display pixels are composed of three colors of R (red), G (green) and B (blue). Defects that occur in units (especially those with green point defects) are eliminated by inspection in panel or module state. In the above-described conventional color liquid crystal display device, a defective portion found by inspection in a panel or module state can be accurately traced at the time of analysis and investigation. However, since it is not possible to determine which of R, G, and B colors required for color display correspond to the defective portion found in the manufacturing process of the thin film transistor array substrate, good / defective cannot be determined in this process, and Allows outflows of defects.

[0005]

In order to solve the above-mentioned problems, a 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. Or the shape of the gate bus line contacting each display pixel is different depending on the color required for color display, or the shape of the storage capacitor contacting each display pixel is different for each color display. It is characterized in that it differs according to the color. Alternatively, a characteristic shape (for example, characters such as R, G, B, and the like) corresponding to each color required for color display is left in each pixel electrode by a transparent electrode removal pattern.

[0006]

Next, 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, the source bus lines 104 and the gate bus lines 103 formed at equal intervals in the vertical and horizontal directions on the glass substrate and ITO (indium tin oxide)
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 formed to be extended on the gate bus line, the pixel electrode has a capacitor with an insulating film interposed between the gate bus line and the capacitor, and this serves as a storage capacitor. Therefore, when a storage capacitor is generally referred to, the overlapping portion of the gate bus line and the pixel electrode itself is indicated. In that case, the pixel electrode (part of the pixel electrode) in the overlapping portion is shielded from light by the gate bus line regardless of the operation thereof, and therefore does not directly contribute to display.

Each of the pixel electrodes has a switching thin film transistor (TFT) 105 for performing 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 becomes defective. It is particularly important that, in the case of a liquid crystal display device intended for color display, the distinction between good and bad depends on the corresponding color of the liquid crystal display portion that is defective. Therefore, in the case of a liquid crystal display device for color display, it is important to obtain information on defective portions in advance. However, a liquid crystal display device is roughly divided into three in a manufacturing process, and a TFT side substrate (hereinafter, a TFT substrate) for actually performing a display operation is manufactured and manufactured.
The TFT substrate and the substrate on the opposite side having the color layer (hereinafter referred to as the opposite substrate) are overlapped with liquid crystal, proceed in the order of modularization, and the actual display becomes possible after the completion of the process. Usually, the defect cannot be specified until it is displayed.

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

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. Similarly, when the colors of R, G, and B are in the delta arrangement as in the embodiment, the identification can be similarly performed, and the delta arrangement exerts a more useful effect.

In the above-described embodiment, the case where the liquid crystal display pixels arranged in a matrix are driven by a thin film transistor which is a non-linear element has been described. The present invention can be applied to all the liquid crystal display devices having the same.
It goes without saying that the present invention is not limited to the illustrated embodiment. Further, the function for each image structure is not limited to the above-described embodiment, and a difference in the shape of the gate bus line in contact with the pixel electrode or a 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. The liquid crystal display device of this embodiment has a source bus line 204 and a gate bus line 203 provided at regular intervals in a vertical and horizontal lattice on a glass substrate, and a transparent electrode of ITO (indium tin oxide) is formed in a region surrounded by the source bus line 204 and the gate bus line 203. LCD pixel 200 comprising 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 many display pixels is defective does not mean that the liquid crystal display device is defective. In particular, in the case of a liquid crystal display device for the purpose of color display, the degree of failure differs depending on the corresponding color of a display pixel that becomes defective. Therefore, it is important to know the defect of the display pixel in advance. Therefore, the transparent electrode ITO
At the same time when the pixel electrode 201 is formed of (indium tin oxide), respective colors R and G prepared on the side of the common electrode opposed to the pixel electrode by photolithography.
.Punched pattern 2 which is a pixel identification function unit corresponding to B
By forming the pixels 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 facing each other are in a delta arrangement, but the colors of R, G and B are stripes. It is a matter of course that the same effect is obtained in the case of an array.

In the above embodiment, the case where the liquid crystal display pixels arranged in a matrix are driven by a thin film transistor which is a non-linear element has been described. However, 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. It goes without saying that the present invention is not limited to the illustrated embodiment.

[0015]

As described above, according to the present invention,
By employing 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 opposed to each other, defects generated in a certain display pixel can be displayed. Needless to say, it is possible to know which color of R, G, and B corresponds to the defect in the state of the thin film transistor array substrate, and to detect defects early, improve work efficiency, and improve the efficiency of countermeasures such as repair. It becomes possible. Further, R
・ The degree of failure is different depending on the defect of any color of G and B. Since it was not possible to specify each color of R, G and B while knowing the defect, it was necessary to proceed to the liquid crystal display state. Waste, such as the case or, conversely, what could have been a non-defective product because the colors of R, G, and B could not be specified, is also reduced.

[Brief description of the drawings]

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

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

FIG. 3 is a schematic plan view of a 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 a conventional technique.

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

FIG. 7 is a further overall schematic diagram of the prior art.

[Explanation of symbols]

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

Claims (2)

(57) [Claims] 1. A color liquid crystal display device controlled by an active matrix driving method, wherein the shape of a gate bus line in contact with each display pixel differs according to each color required for color display. Display device. 2. 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 pattern of a transparent electrode. Characteristic liquid crystal display device.