JPS5872183A - Liquid crystal display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device using liquid crystal. For more details, please see! The present invention relates to a structure and method capable of correcting defects in IM elements coupled to each display pixel of a trix-aligned liquid crystal display.

With the increase in capacity of liquid crystal display devices, matrix display systems are entering the practical stage. This matrix display method is
The purpose is to display characters at the intersections of a large number of electrodes arranged in the Y direction, and time-division driving is performed by sequentially scanning lines in the xt or Y direction. When a desired timing line is selected, a signal for turning on or off display pixels is simultaneously applied to all electrodes connected to the data line on the electrodes connected to the timing line.

At this time, the effective voltage of the voltage applied to the intersection is v
If it becomes sufficiently larger than th, it turns on, and in the opposite case, it turns off. However, as the number of timing lines increases, the ratio of the effective voltage when selected (on) and when not selected (off) increases.
The ratio of the non-selected period to the selected period increases and becomes smaller. Therefore, if the drive voltage is constant, the on level will be low and sufficient contrast will not be obtained. Although it depends on the type of liquid crystal, the practical limit is about 1/16th of the DET.

Conventionally, a nonlinear element and a display pixel have been combined in order to increase the duty factor. FIG. 1 shows the equivalent circuit, and the timing line 101. A data line 1029, a display pixel 103, and a nonlinear element (M element) 104.

One electrode of the display pixel is an electrode connected to the timing line, and one electrode of the M element 104 is an electrode connected to the data line. Next, the static characteristics of the M-type V element are shown in FIG. According to this current-voltage characteristic, if the absolute value of the voltage is small, the impedance between the MIMs is very large, but the absolute value of the voltage increases. The impedance therefore decreases exponentially.

By scanning the timing line at a constant cycle, a selection or non-selection voltage is applied to the electrodes sequentially connected to the timing line. When the imperial timing line is selected, a signal for selecting the on or off state of the liquid crystal is applied to all lines simultaneously to the data line (M element side) corresponding to the line (liquid crystal side). . At this time, the on/off state of the liquid crystal is determined depending on the level of the signal, and the liquid crystal is charged with electric charge from the M1M element. When the timing line is deselected, the impedance of the M/V element increases, the discharge of the stored charge decreases, and the data is retained. When the liquid crystal is on, the effective voltage is Te of the liquid crystal.
The deity can be raised until it drops to the at position.

Since the liquid crystal display device described above is a dot matrix display, the area of the M element that does not contribute to display should be made very small, and the capacitance ratio with the liquid crystal layer and the current-voltage characteristics should be improved. Therefore, in order to improve the performance of M-engineered M-devices, it is necessary to make the tantalum pentoxide film, which is an insulator, extremely thin. Although it varies somewhat depending on the capacity, size, and resolution of the display, the size of the M element is several microns. In order to form such a small element on a glass substrate or the like, about 7 etching steps are used, but it is extremely difficult to etch the remaining portions except for a line width of several micrometers. Furthermore, since the entire display has a large area ranging from several centimeters to over ten centimeters, it is difficult to uniformly etch the display. Furthermore, since the tantalum pentoxide film is only a few hundred micrometers thick, the M port I terminal is easily short-circuited and disconnected due to occurrence of pinholes, adhesion of foreign matter, scratches, etc. Since pixel defects due to the above-mentioned defects and the five process defects usually occur at several locations on a single panel, it is desirable to have an M-process M element with a structure that can correct the defects that occur, and a simple correction method. .

The present invention eliminates the above-mentioned drawbacks, and its purpose is to provide a structure that allows the defects that have occurred to be corrected, and also to provide a method for such correction.

The present invention will be explained in detail below based on examples.

FIG. 3 is an equivalent circuit for realizing an embodiment according to the present invention. 301 to 304 in the figure are the same as in FIG. 1 and are omitted.

In the figure, 305 is a display pixel of the same size as 503;
06 is an M-y element of the same size as 504.

FIG. 4 is an external view of the first embodiment according to the present invention. In the figure, 401 is a timing line (electrode), which is the part drawn with a dotted line, 402 is a data line, and 40
3 is an M element, and 404 is a liquid crystal drive electrode. Two M elements are formed on one timing line (electrode) of the imperial order, and the liquid crystal drive electrode is divided into two to form the M x w
1g child each. The two M devices are connected to the same data line, and one liquid crystal display,
is composed of a display pixel and two M elements. After forming the liquid crystal drive electrode, the current-voltage characteristics of the liquid crystal drive electrode connected to the data line and one V element are determined as follows: 4 and check for defects.

A method for correcting defects will be explained next with reference to FIG.

Unlike FIG. 4, FIG. 5 does not have a timing line, but is otherwise the same diagram. 5 circled in the diagram
01 is due to a defect in the M element at that location.
This is the part cut from the data line by the laser pairing device. Next, a circle mark 502 indicates that one of the two M elements forming one liquid crystal display body and the liquid crystal drive electrode connected to one M port of each is defective, and the other non-defective liquid crystal Connect the defective liquid crystal drive electrode to the drive electrode. Although connections are made at three locations in this embodiment, the connection is not limited thereto. Also,
By narrowing the space between the VM element and the liquid crystal driving electrode that form one liquid crystal display, and widening the space between them and other liquid crystal display elements, the connection of the NESA electrodes is facilitated, and one set of Next, a method of connecting the liquid crystal drive electrodes will be described in order to make it easier to distinguish the MIM elements, but this is one method and is not limited to this method.

FIG. 6 shows a pattern of high melting point metals (Or, Tas, Ni, F) on a glass substrate 601 as shown in the figure.
e.

MO, etc.) 602 is formed.

FIG. 7 is a simple schematic diagram of the connection method, and 701 in the figure
．． 702 is a liquid crystal driving electrode, 703 is a high melting point metal film formed in the pattern shown in FIG. 6, and 704 is a respective glass substrate. On the liquid crystal drive electrode that you want to connect as shown in the figure,
When the high melting point metal film is adjusted so that it is placed on top and a laser repair device or laser beam 11705 is irradiated onto the liquid crystal drive electrode from the back side of the high melting point metal film, the high melting point metal film becomes m- and evaporates. It can be deposited on the electrode. Even if there is a disconnection between the M element and the data line, it can be corrected by using the connection method described above.

According to the present invention, even if a defect occurs in the M element, the liquid crystal can be driven using another M element of the same liquid crystal display, making it easy to create a defect-free liquid crystal display device. can be realized. - In the present invention, one liquid crystal display body is composed of a display pixel, two M1 elements, and a Nesa film connected to the two M elements, but the M element and the Nesa film are The import is not limited to 2 items, but 2 or more items are also acceptable.

[Brief explanation of the drawing]

FIG. 1 shows an equivalent circuit of a conventional liquid crystal display device. FIG. 2 shows an example of current-voltage characteristics of an MIM element. FIG. 3 is an equivalent circuit of the embodiment according to the present invention. FIG. 4 is an external view of an embodiment according to the present invention. FIG. 5 is an explanatory diagram of an embodiment according to the present invention. FIG. 6 is an external view of an example in which a high melting point metal film is patterned on a glass substrate. FIG. 7 is a schematic diagram of an example of a method of connecting liquid crystal drive electrodes. Above 1o/ Figure 2 Figure 3 407 Figure 4 Figure 5 Figure 6 Figure 7 ■

Claims (1)

[Claims] A non-i** element (hereinafter referred to as V
In a liquid crystal display body that combines
Each of the liquid crystal leaking bodies is characterized by comprising a display pixel, 211 or more MIM elements connected to the same data line, and liquid crystal drive electrodes having the same area and connected to each of the two or more M elements. A liquid crystal display device.