JPH0317632A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To eliminate a flicker on a display screen due to the asymmetry of the current-voltage characteristic of a nonlinear resistance element which is connected between mutually adjacent display picture element electrodes by constituting the nonlinear resistance element in reverse structure. CONSTITUTION:A nonlinear resistance element 14 for the display picture element electrode 12 of a part A has its lower metal 15 connected to a wiring electrode 13 and its upper electrode 17 connected to a display picture element electrode 12, and nonlinear resistance element 14 for the display picture element electrode 12 of a part B has its upper metal 17 connected to the wiring electrode 13 and its lower metal 15 connected to the display picture element 12. Thus, the nonlinear resistance elements 14 connected between the mutually adjacent picture element electrodes 12 are in the reverse structure, so even if the current-voltage characteristics of the nonlinear resistance elements 14 have some asymmetry between the positive and negative directions, the effect is canceled between the adjacent picture element electrodes 12 to eliminate the flicker on the display screen.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a liquid crystal display device, and particularly to a liquid crystal display device using a nonlinear resistance element as a switching element.

(Prior Art) In recent years, liquid crystal display devices have been used for everything from relatively simple devices such as watches and calculators to large-capacity display applications such as personal computers, word processors, office automation terminal equipment, and television image displays. It's coming. In such large-capacity liquid crystal display devices, a multiplex drive system for matrix display is generally adopted. However, in this method, the contrast ratio between the display portion and the non-display portion deteriorates as the number of scanning lines increases, making it unsuitable for large-scale matrix driving.

Therefore, as a means to solve this problem, a method is used in which each pixel is driven by a switching element. A thin film transistor or a nonlinear resistance element is used as the switching element, but a nonlinear resistance element with two terminals and a simple structure is basically advantageous in terms of manufacturing and cost.

Various methods have been developed for this nonlinear resistance element, and among them, the metal-insulating-film-one-metal (Meltl-1n) method has been developed.
sulxlor-Mel1l) (hereinafter MIM)
Structures have been put into practical use.

FIG. 4 is a cross-sectional view showing an example of one pixel portion of an array substrate having MIM elements. This device forms a wiring electrode (not shown) on a substrate 1 made of glass, and a lower metal 2 (one side of M) integrally connected to the wiring electrode. Te MI. An upper metal 4 is formed on the other side of M, and this upper electrode 4 is connected to a display pixel electrode 5 formed on the substrate 1. Display pixel electrodes 5 having MIM elements having the same structure are arranged in a matrix.

(Problems to be Solved by the Invention) Although the above-mentioned MIM elements have improved characteristics, they have not yet achieved completely symmetrical current-voltage characteristics in the positive and negative directions. For this reason, in liquid crystal display devices that are forced to drive with alternating current to prevent deterioration of the liquid crystal, there is a difference in the potential written to the display pixel electrode between positive and negative polarities, which causes flickering. ing.

The present invention aims to solve the above problems, and
It is an object of the present invention to provide a liquid crystal display device that does not cause flickering even if the current-voltage characteristics of an M element are asymmetrical to some extent and is easy to manufacture.

[Structure of the invention]

(Means for Solving the Problems) A liquid crystal display device of the present invention includes a plurality of display pixel electrodes formed on a substrate and a plurality of nonlinear resistance elements, each nonlinear resistance element being formed on the substrate. A lower metal and an upper metal are formed opposite to each other with an insulator interposed therebetween, and are connected to each of the display pixel electrodes, and are also connected to each row or column by a wiring electrode, and the adjacent display The nonlinear resistance element for the pixel electrode has one side that connects a lower metal to the wiring electrode and an upper electrode to the display pixel electrode, and the other side that connects the upper metal to the wiring electrode and connects the lower metal to the display pixel electrode. It is connected to.

(Function) In the present invention, the nonlinear resistance elements connected between adjacent display pixel electrodes have an inverse structure, and if the current-voltage characteristics of these nonlinear resistance elements have a certain degree of asymmetry in the positive direction and the negative direction. Even if this occurs, the effect is canceled out between adjacent display pixel electrodes, so that flickering on the display screen can be eliminated.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIGS. 1 and 2, reference numeral 11 denotes a substrate made of glass or the like, and a large number of display pixel electrodes 12 are formed on this substrate 11 at predetermined intervals. Furthermore, wiring electrodes 13 are formed on the substrate If along each of the display pixel electrodes l2. Each of the display pixel electrodes 12 is a wiring electrode l3.
are connected to each row or column by a nonlinear resistance element 14. Each nonlinear resistance element 14 includes a lower metal 15 formed on the substrate 11, and a lower metal 15 formed on the substrate 11.
An upper metal 17 is formed on top with an insulator 16 interposed therebetween.

The nonlinear resistance elements l4 are connected vertically to the display pixel electrodes 12 adjacent to each other. That is, in the display pixel electrodes l2 adjacent to each other as shown in sections A and B in FIG. 1, the nonlinear resistance element 14 for one display pixel electrode I2 in section A in FIG.
0, the lower metal 15 is connected to the wiring electrode l3, and the upper electrode 17 is connected to the display pixel electrode 12, and the nonlinear resistance element l4 is connected to the other display pixel electrode l2 in part B of FIG. As shown in FIG. 2(b), the upper metal 17 is connected to the wiring electrode 13, and the lower metal 15 is connected to the display pixel electrode 12.

Next, the method for manufacturing the above liquid crystal display device is shown in FIGS. 2 and 3.
This will be explained with reference to the figures. This FIG. 3 shows the manufacturing process of two adjacent pixel parts.

First, as shown in FIG. 3(i), a first metal layer made of Ti or the like is formed into a thin film by sputtering on a substrate li made of glass or the like, and this first metal layer is patterned. 1 wiring electrode 13m and nonlinear resistance element 14
Lower metal +5J,,. Form J5b. On this occasion,
One lower metal 151 of the nonlinear resistance elements 14 adjacent to each other is connected to the t-th wiring electrode 13! The other lower metal 15b is formed integrally with the lower metal 15b.

Next, an insulator 16 such as 710 is placed on the entire surface of the substrate 11.
A thin film is formed by sputtering, and this insulator 16
A second metal layer made of Cr, AI, etc. is formed as a thin film on top, and this second metal layer is patterned as shown in FIG.
), the upper metal 17s. l? form b. At this time, the lower metal 15r is the first wiring electrode 13! The upper metal 171 of one of the nonlinear resistance elements 14 connected to the display pixel electrode 12 forms a pattern connected to the display pixel electrode 12, and the lower electrode 15b forms a pattern connected first to the display pixel electrode l2. The upper electrode 171I of the other nonlinear resistance element 14 has a pattern so that a portion thereof overlaps from the lower electrode 17b to the first wiring electrode 131.

Next, using the same pattern as the second metal layer, ie, the top metal 171. After patterning 17b, the resist is left and the insulator 16 present in areas other than the nonlinear resistance element 14 is removed by etching.

Finally, a thin transparent conductive film made of ITO was formed on the entire surface by sputtering method, and patterned.
As shown in i), the upper electrode 17a and the lower electrode +
The display pixel electrode 12s connected to the display pixel electrode 12s.5b. 12b and the first wiring electrode 13! A second wiring electrode tab is formed on top of this first wiring electrode! 31 and second wiring electrode +3
A wiring electrode l3 is formed which is integrated with b.

Although not shown, the substrate 11 on which the display pixel electrode 12 and the nonlinear resistance element 14 are formed as described above is placed opposite to the substrate on which a transparent counter electrode is formed at a predetermined distance, and a liquid crystal is sealed in between. Configure the display.

As described above, the nonlinear resistance elements 14 having mutually opposite structures can be formed in the adjacent display pixel electrodes 12 by performing the conventional three photolithography steps.

In this way, the nonlinear resistance elements 14 connected between the display pixel electrodes 12 adjacent to each other have an opposite structure.

Therefore, even if a certain degree of asymmetry occurs in the current-voltage characteristics of these nonlinear resistance elements l4 in the positive and negative directions, the effect is canceled out between adjacent display pixel electrodes 12, so that the display screen is Flickering can be eliminated.

[Effects of the Invention] According to the present invention, the nonlinear resistance elements connected between the display screen xi poles adjacent to each other have an opposite structure, and the display screen changes due to the asymmetry of the current-voltage characteristics of the nonlinear resistance elements. Flickering can be eliminated. Further, in its manufacture, it can be easily shaped using conventional processes.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an embodiment of the device of the present invention, and Fig. 2 (s), (b), and (c) are parts a-a and b of Fig. 1, respectively.
3 is an explanatory view showing the manufacturing process, and FIG. 4 is a sectional view of a conventional device. 11...Substrate, 12...Display pixel electrode, l3...Wiring electrode, 14...Nonlinear resistance element, 15...Lower electrode, l6
...Insulator, 17...Top electrode. Board display picture book Yukoku kJ Buyu Gokui Bu-gata coffin test piece Lower metal flooded wood Upper part Katoga, Cb) House

Claims (1)

[Claims] (1) A plurality of display pixel electrodes formed on a substrate; a lower metal and an upper metal are formed oppositely on the substrate with an insulator interposed therebetween, and are connected to each of the display pixel electrodes; a plurality of nonlinear resistance elements connected in rows or columns by electrodes; and a plurality of nonlinear resistance elements for the adjacent display pixel electrodes, one of which connects a lower metal to the wiring electrode, and an upper metal of the nonlinear resistance element connected to the wiring electrode. A liquid crystal display device, characterized in that an electrode is connected to the display pixel electrode, an upper metal is connected to the wiring electrode, and a lower metal is connected to the display pixel electrode.