JPH0473569B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an active matrix liquid crystal display device, and is aimed at correcting pixel defects that occur during the manufacturing process. This will be explained below with reference to the drawings.

Liquid crystal display devices are widely used in watches, calculators, etc., and are one of the most promising display devices in the future, due to their features such as small size, light weight, low power consumption, and light-receiving display devices. Among these, the active matrix type, in which switching elements that turn on and off the signal lines and pixel drive electrodes are formed in the substrate, can achieve a liquid crystal drive duty ratio of 100% if the pixel drive voltage can be maintained, and can achieve a large liquid crystal drive duty ratio of 100%. Suitable for high-definition screens and fine pixels. However, as the pixel size becomes smaller, the storage capacitance that sandwiches the liquid crystal between the pixel drive electrode and the counter electrode for holding the pixel drive voltage decreases, and the voltage cannot be maintained unless additional capacitance is added. For this reason, a method is used to form a storage capacitor in the active matrix substrate. In this case, if a part of the pixel drive electrode is used, a TN type liquid crystal that allows light to pass through the active matrix substrate is used. When used, there are problems such as a decrease in light transmittance, a decrease in display contrast, and a deterioration in display quality. Therefore, a method is adopted in which a capacitor is formed between the pixel drive electrode and the wiring line adjacent thereto. This method creates a capacitance between a timing line at a non-selected level and a timing line immediately before the timing line currently at a selected level and the pixel drive electrode.

Figure 1 shows the configuration of a conventional active matrix board, in which the timing line 2, which is currently at the selection level, indicates the switching element.
MOS transistor 8 is turned on and data line 1
The pixel drive electrode 6 is charged with the signal. At this time, as shown in the circuit diagram of Figure 2, the signal on data line 1 is
Through the MOS transistor 8, the capacitor 4 formed by the pixel drive electrode and the electrode on the glass substrate constituting the liquid crystal cell and the capacitor 5 formed between the pixel drive electrode and the timing line 3 at the non-select level are respectively connected. Charge. As a result, the decrease in capacitance 4 due to the reduction in pixel size can be compensated for by capacitance 5, but on the other hand, the pixel drive in the portion 3 where the pixel drive electrode and the non-selection level timing line overlap, If a pinhole occurs in the insulating film sandwiched between the electrode and the timing line at the non-select level during the manufacturing process, the pixel drive electrode will be kept at the non-select level of the timing line and the signal from the data line will be erased. The probability of occurrence of such pinholes is high because the area of the formed electrode 7 is quite large in the entire display device. In this case, for the display device, the pixel remains lit or does not light at all, resulting in a pixel defect, resulting in a significant deterioration in quality.

Therefore, in the present invention, a method for later correcting such defects is provided, and as shown in FIG. This is to create a pattern that is separated by

If a defect due to a pinhole actually occurs in the electrode 7 using this pattern, the connecting portion 9 is cut by a laser or the like and completely separated from the pixel drive electrode 6, so that the pixel drive electrode does not select the timing line. It is not maintained at the same level, and the voltage holding capacity as a pixel becomes only capacitor 4, but it is not an extreme defect state such as whether it is lit or not lit, but it is caused by the signal from the data line. It will be under control and will improve considerably.

As described above, the present invention forms a liquid crystal display capacitor by an electrode electrically connected to the pixel electrode via a connection part and the timing line in the preceding stage, and the width of the connection part is set to the width of the pixel electrode. Because it is narrower than the width, if a leakage defect occurs due to a pinhole in the insulating film that makes up the display capacitor, the display defect can be eliminated by cutting the connection between the display capacitor and the pixel drive electrode. It is possible to improve yield and display quality.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a conventional active matrix board. FIG. 2 is an electrical circuit diagram of FIG. 1. FIG. 3 is a configuration diagram of a pixel drive electrode and a capacitor electrode according to the present invention. 1... Data line, 2... Timing line currently at the selected level, 3... Timing line currently at the non-selected level, 4... Capacitance created by sandwiching the liquid crystal between the pixel drive electrode and the counter electrode, 5... Capacitance created between the pixel drive electrode and the timing line 3 at the non-select level, 6... Pixel drive electrode, 7... Electrode connected to the pixel drive electrode 6 constituting the capacitor 5, 8...
...MOS transistor, 9...Slit dividing the pixel drive electrode and capacitor electrode, 10...Connection portion between the pixel drive electrode and capacitor electrode.

Claims (1)

[Claims] 1. A liquid crystal layer sandwiched between a pair of substrates, pixel electrodes arranged in a matrix on one of the pair of substrates, and a data signal supplied to the pixel electrodes. In an electro-optical display device having a data line formed by a data line and a timing line formed by supplying a timing signal to the pixel electrode, the liquid crystal display capacitor is electrically connected to the pixel electrode via a connection part. A liquid crystal display device, characterized in that the width of the connection portion is narrower than the width of the pixel electrode.