JPH0381735A - Active matrix type liquid crystal display panel - Google Patents

Abstract

PURPOSE:To prevent a defect caused by the deterioration of a thin film transistor (TFT) from expanding to the circumference thereof by making the common electrode of facing substrates which face to an active element substrate and which interpose a liquid crystal layer in a prescribed pattern. CONSTITUTION:The common electrode E' formed by an electrode main part 7 and a connecting line 8 is provided on the facing substrate which is faced to the active element substrate where a picture element electrode and the TFT are arranged in a matrix state. Then, the main part 7 can be easily separated by cutting the line 8 with the aid of a laser. By the separation, the defect of display caused by the deterioration of the TFT is easily and surely prevented from expanding to the circumference thereof.

Description

[Detailed Description of the Invention] [Summary] An object of the present invention is to provide an active matrix liquid crystal display panel that can prevent display defects from spreading to surrounding areas even if a point defect occurs. An active element substrate having pixel electrodes and switching elements corresponding to the pixel electrodes arranged in a matrix on its surface, a counter substrate having a common electrode arranged on its surface, and an active element substrate sandwiched between the active element substrate and the counter substrate. In the configuration of an active matrix type liquid crystal display panel comprising a liquid crystal layer, the common electrode is provided with an electrode main part at a portion facing each of the pixel electrodes, and a connecting line is connected between adjacent electrode main parts. The configuration is such that the pattern is connected by .

[Industrial application field]

The present invention relates to an active matrix liquid crystal display device, and particularly to a configuration for obtaining high image quality.

In recent years, liquid crystal display panels have been put into practical use in pocket TVs and the like, and higher image quality and longer lifespan are required.

[Conventional technology]

The structure of a conventional active matrix liquid crystal display panel is shown in FIGS. 3 and 4. The main part plan view of FIG. 3 schematically shows the planar configuration of the active element substrate, and the main part sectional view of FIG. 4 shows the cross-sectional structure of the liquid crystal display panel.

The active element substrate 1 has pixel electrodes E arranged in a matrix on a glass substrate Fi3, and each pixel electrode E is provided with at least one switching element, for example, a thin film transistor T. An alignment film 5 is formed thereon.

The counter substrate 2 has a common electrode E' formed on a glass substrate 4 and an alignment film 5 formed thereon.

A liquid crystal N6 is sandwiched between these two substrates 1 and 2, and the liquid crystal molecules are aligned in a predetermined direction by the alignment film 5.

Further, SB is a scan path line, which connects the gate electrodes of thin film transistors T belonging to the same row in common, and supplies a scan signal of TPT. DB is the data bus line.
Supply display data.

In the liquid crystal display panel configured as described above, the thin film transistor T may become a defective element for some reason during the manufacturing process. Even if this defective element remains as a point defect, as the driving time of the liquid crystal display panel passes,
There is a problem in that the display defect spreads around the area.

[Problem to be solved by the invention]

The reason why the display defect spreads around this point defect is that in the point defect area, the non-selection voltage of the gate (for example -1OV) is applied to the pixel electrode.
is applied, so a DC bias is applied to the liquid crystal. Therefore, it is thought that the electric charge spreads from the point defect to the surrounding pixels, causing the display of the surrounding pixels to become abnormal.

An object of the present invention is to provide an active matrix liquid crystal display panel that can prevent display defects from spreading to surrounding areas even if a point defect occurs.

[Means to solve the problem]

In the present invention, the common electrode on the surface of the counter substrate has a main electrode portion facing each pixel electrode on the surface of the active element substrate, and a connection line connecting adjacent main electrode portions.

[For production]

According to the present invention configured as described above, when a point defective element occurs, the connection line connected to the electrode main part of the common electrode corresponding to the defective element is cut by laser irradiation, thereby cutting off the electrode main part. Separate. Since the main part of the electrode separated in this way becomes floating, no direct current bias is applied to it, thereby preventing display defects from spreading to the surrounding area.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of the common electrode E° of this embodiment. As shown in the figure, the common electrode E' has electrode main parts 7 arranged opposite to each pixel electrode on the active element substrate 1, and the adjacent electrode main parts 7 are connected by !+3. The structure is as follows.

As mentioned above, the pattern of the common electrode E' is different from the conventional solid electrode, but there is no need to change the material or anything else.

When a point defect occurs in this embodiment configured as described above, as shown in FIG.
The connecting wire 8 connected to the common electrode E'' is cut by laser irradiation, and this electrode main portion 7'' is electrically separated from the common electrode E''.9
indicates the cutting point.

The electrode main portion 7' electrically separated from the common electrode E' becomes electrically floating, and the non-selection voltage of the gate electrode is not applied to the defective pixel, so that the display defect does not spread to the surrounding area.

When carrying out the present invention, the manufacturing process of the active element substrate may be the same as the conventional one, and the manufacturing process of the counter substrate differs only in that the common electrode is shaped like a grid, as described above, and there is no need to change anything else. do not have.

In addition, in the above embodiment, the upper, lower, left and right electrode main parts 7 are connected! 8 has been described, however, diagonally adjacent electrode raw portions 7 may be connected, and the connection method is arbitrary. In short, the arrangement and pattern should be such that the connecting wire 8 can be easily cut.

〔Effect of the invention〕

As described above, according to the present invention, even if a point defect due to a defective TPT exists in an active matrix liquid crystal panel, the defect can be prevented from spreading to the surrounding area.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the configuration of an embodiment of the present invention, Fig. 2 is an explanatory diagram of a method for cutting the main part of an electrode at a point defect, Fig. 3 is a plan view of the main part of a conventional liquid crystal display panel, and Fig. 4 is a conventional diagram. FIG. 2 is a sectional view of main parts of a liquid crystal display panel of FIG. In the figure, ■ is an active element substrate, 2 is a counter substrate, 3.4
is a glass substrate, 5 is an alignment film, 6 is a liquid crystal layer, 7 is an electrode main part, 8 is a connection line, E is a pixel electrode, E゛ is a common electrode, T is a thin film transistor, SB is a scan path line, DB is a data bus Show the line. Ntoito day ear - Shizukuzaka arrow tip end〆e''j SoO ear 1st figure Manga Wm97 n 'l Takisu no Kiri Chuko 1 x Ming 1 enemy 2nd figure

Claims (1)

[Scope of Claims] An active element substrate with pixel electrodes and switching elements corresponding to the pixel electrodes arranged in a matrix on the surface, a counter substrate with a common electrode arranged on the surface, and a combination of the active element substrate and the counter substrate. In the configuration of an active matrix liquid crystal display panel comprising a liquid crystal layer sandwiched between the common electrode and the pixel electrode, the common electrode is provided with an electrode main part at a portion facing each of the pixel electrodes, and an adjacent electrode main part. An active matrix liquid crystal display panel characterized by a pattern in which the spaces are connected by connecting lines.