JPH03196019A - Matrix type display device - Google Patents

Abstract

PURPOSE:To reduce point defects occurring in each one of image elements on a display device and to make it difficult to find the occurring point defects by dividing the electrode of each image element into plural fractions distributed into the whole area of each one image element and alternately intruding it into the divided image element electrode without contacting with each other and connecting one or more switching element with each image element electrode. CONSTITUTION:The 2 switching elements are connected to each one image element electrode, and an amorphous silicon film or a multicrystalline silicon film or the like is used as a TFT active layer. The image element electrode is divided into 2 electrodes P11, P12 per one image element, and they are formed into a comb-like form, alternately intruding into each other, and designed so as to distribute on the whole area of the image element, thus permitting the remaining divided image element to cover point defect of the other divided image element, even if it causes point defect due to disconnection due to poor patterning or the like, and the point defect of the divided image element to be made difficult to be found, and accordingly, the point defects of the image elements to be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a matrix type display device, particularly to the structure of a matrix array substrate.

[Conventional technology]

Conventional matrix display devices have -a on the substrate! It has a structure in which a number of row lines and a plurality of column electrode lines are arranged to intersect with each other, and a switching element and a pixel electrode are arranged at each intersection.

FIG. 4 shows an example of a matrix array substrate of such a matrix type display device, and in the figure, (g 1
) (g z)−・(g,) is the row electrode line, (S,)(s
=) -(S-) is the column electrode line, (1,) (1
, )(t3)... is a switching element connected to the intersection of each electrode wiring, (p□) (p =) (p =)
is a pixel electrode connected to each switching element. A liquid crystal display device is constructed by configuring such an arrangement on at least one of a pair of opposing substrates, and sandwiching a display material such as liquid crystal between the other opposing electrode substrate having a transparent electrode.

In this matrix type display device, as the screens of television receivers and the like have become larger in recent years, the screen size has been increasing, that is, the area of the matrix screen display portion has been increasing. In the manufacturing process of this type of liquid crystal display device, patterning defects occur due to foreign matter adhering to a mask used in photolithography technology.

That is, when a thin film transistor (hereinafter abbreviated as TPT) is used as a switching element, for example, a pixel electrode and a TPT are used.
If part of the metal film pattern is missing at the connection part with the drain electrode of PT, and no electrical connection is made,
In a display mode in which light is transmitted when a video signal voltage is applied to the liquid crystal (the same mode will be described below), a point defect occurs in which the pixel does not light up. In addition, for example, when the drain Th electrode and the pixel electrode are brought into contact by patterning a hole in an insulating film sandwiched between them, the hole may not be formed properly due to a patterning defect during the process. , point defects similar to those described above occur. Such point defects are more likely to occur because as the area of the matrix screen display area increases, the number of pixels also increases, and the probability that dust or the like will adhere to the substrate increases.

For this reason, in the past, one pixel was divided into two or more dots, and even if one dot stopped lighting due to a point defect, the remaining dots would cover it, making the point defect less visible. It is taken.

Figure 5 shows the case where the pixel electrode is divided into two dots and one T P T (t 11) # (t st) is connected to each divided pixel electrode (p + tL (p * 2)) of each dot. This figure shows an example of the structure of a matrix array substrate.

Note that an example in which a pixel electrode is divided into three dots is disclosed in Japanese Patent Application Laid-Open No. 63-309921. In the figure, for example, a dot divided pixel electrode (p□,) on one side
Even if the pixel does not turn on due to a point defect, if the other divided pixel electrode (pa□) is normal, it is not a point defect in the entire pixel, so the point defects in the pixel can be reduced.

[Problem to be solved by the invention]

Conventional matrix type liquid crystal display devices are constructed as described above, and in liquid crystal display devices with redundancy in which one pixel is divided into multiple dots, the number of divided dots is particularly large as shown in Fig. 5. In the case of a simple rectangular display electrode with about 2 display electrodes, if one side of the display electrode stops lighting up, the 172 rectangular part of one pixel becomes completely heated, so it cannot be seen with the naked eye. The problem was that they could be clearly identified.

The matrix type display device of the present invention provides a technique that can reduce point defects in which all pixels of a display section are defective, and also make it possible to make the point defects that occur difficult to see.

[Comprehensive means to solve problems]

The matrix type display device according to the present invention has a structure in which a pixel electrode is divided into a plurality of parts, each divided pixel electrode has a shape that meshes with each other without touching each other, and is distributed throughout one pixel. In addition, one or more switching elements are connected to each divided pixel electrode.

[Effect]

In this invention, even if a part of a pixel made up of divided pixel electrodes has a point defect in which it does not light up, the divided pixel still remains intact.
Since Hi is distributed over the entire pixel in a shape that interlocks with each other, the brightness of the entire pixel is reduced by the divided pixel T.
Although it decreases by the amount of i-pole, with the addition of light diffusivity,
Since the shape of a pixel that is not lit is almost impossible to discern with the naked eye, even if a point defect occurs, it can be made difficult to see.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a plan configuration diagram showing an example of the configuration of a matrix array substrate of a matrix type display device according to an embodiment of the present invention. In the figure, (g1) (gz)... are row electrode lines for screen display. , (S t) (s , )・ are column electrode lines for screen display, ((, □) (tin) are switching elements such as TPT, and in the case of the same figure, there are two switching elements for one pixel. is formed, and an amorphous silicon film, a polycrystalline silicon film, or the like is used as the active layer of the TPT.

In addition, (p 11) (p t□) are each divided pixel electrodes, and in the case of the same figure, one pixel is divided into two,
The shape is such that the divided pixel electrodes interlock with each other in a comb shape, and one comb-shaped divided pixel electrode is designed to be distributed over the entire surface of the pixel as much as possible.

In addition, even if one of the divided pixels becomes a point defect due to disconnection due to poor patterning, etc., and does not turn on, it can be covered by the remaining divided pixels, and in that case, fg5
Compared to the conventional case where a pixel is divided into two by a simple rectangle as shown in the figure, each divided pixel is distributed over the entire pixel as much as possible, so even if only one side is lit, the light Combined with the diffusivity, defects in divided pixels can be made more difficult to see. Furthermore, although the total brightness of a defective pixel decreases, it is no longer a point defect in which the entire pixel does not turn on, so it is possible to reduce point defects in the pixel.

In addition, above we talked about the case where one divided pixel does not turn on due to a patterning defect, etc., but due to a pattern defect or fine metal particles, a switching element such as a TPT shorts out and one of the pixels is always turned on. In this case as well, point defects become more difficult to see than in the case of dividing into simple rectangles as described above.

In addition, as a method for redundancy of matrix array board,
There is a method in which two or more switching elements are connected to one pixel, so that even if one switching element becomes open due to poor patterning, the remaining elements drive the pixel electrode. If two switching elements are short-circuited (in the case of TPT, the source electrode and drain electrode are short-circuited), the input of the video signal line (source signal) is determined whether or not the scanning signal (gate pulse signal) is input to the element (gate electrode). Regardless of the voltage, the voltage is always applied to the pixel electrode, resulting in a point defect in which the entire pixel is constantly lit. In contrast, in the display device according to the present invention, even if one divided pixel is constantly turned on due to a short-circuit defect, the overall brightness increases and the contrast ratio decreases when compared pixel by pixel compared to a normal pixel. If the remaining divided pixels operate normally, the brightness characteristics will change to some extent depending on the strength of Image I3, so this together with the light diffusivity due to the shape of the divided pixels may cause the defect of the constant lighting state. You can even see the pixels,
It becomes more difficult to see as a point defect with the naked eye.

Note that in the above embodiment, the shape of the divided pixel electrodes is comb-shaped in the case of two divided pixels, but the shape of the dot display electrodes may be spiral-shaped as shown in FIG.
If there are three divided pixels, for example, a configuration as shown in FIG. 3 may be used, and the same effects as in the above embodiment can be achieved.

Further, in the above embodiment, a matrix type display device using a switching element such as TPT has been described, but it may also be applied to a simple matrix type liquid crystal display device that does not use a switching element such as TPT, and the above embodiment may be applied to a simple matrix type liquid crystal display device that does not use a switching element such as TPT. It has the same effect as the example.

〔Effect of the invention〕

As described above, according to the present invention, one pixel electrode is divided into a plurality of parts, and each divided pixel electrode is distributed over the entire area within one pixel and meshes with each other without touching each other. shape, and is configured such that one or more switching elements are connected to each of the divided pixel electrodes,
The probability that an entire pixel becomes a point defect can be lowered, and even if a certain divided pixel electrode becomes defective, the defect is more difficult to see than when it is divided into simple rectangles as in the past. Therefore, the display quality of the matrix type display device can be further improved, and the manufacturing yield can be improved.

[Brief explanation of drawings]

FIG. 1 is a plan configuration diagram showing an n-matrix array substrate of a matrix type display device according to one embodiment of the present invention, and FIGS. 2 and 3 are respectively matrix array substrates of matrix type display devices according to other embodiments of the present invention. A plan configuration diagram showing
FIG. 4 is a configuration diagram showing a matrix array substrate of a conventional matrix type display device, and FIG. 5 is a plan configuration diagram showing a matrix array substrate of a conventional matrix type display device. (g +L (g +) row electrode line, (s,),
(s engineering) Column electrode wire, (LIIL(tl□), (1,3)
...Switching element, (p t+), (p +t)
(pls) Divided pixel electrodes In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] On an insulating substrate, a plurality of row electrode lines parallel to each other, a plurality of column electrode lines intersecting these row electrode lines and parallel to each other, and a switching element connected to the intersection of the row electrode line and the column electrode line. and a matrix type display device comprising a pixel electrode for screen display connected to the switching element, and a counter electrode arranged on the insulating substrate via a display material, wherein the pixel electrode is divided into a plurality of parts. At the same time, each of the divided pixel electrodes has a shape that meshes with each other without contacting each other, and is configured to be distributed throughout one pixel, and one or more switching elements are connected to each of the divided pixel electrodes. A matrix type display device characterized by: