JPH04133025A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To perform multicolor display whose display quality is improved by forming a segment electrode in an interdigital shape. CONSTITUTION:Plural segment electrodes 2 by which squarish 8-shaped segment is constituted are formed on a transparent substrate 1a. The segment electrode 2 is formed in the interdigital shape by using electrodes 2a and 2b. Thus, the multicolor display is performed in a static driving system and the display contrast is improved, furthermore the pattern of a leading wire is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device in which transparent electrodes have an interdigital shape.

(b) Conventional technology Conventionally, liquid crystal display elements for displaying numbers using a segment method that can switch between two or more display colors (hereinafter referred to as multi-color) have been either dot matrix method or general segment type liquid crystal display. A so-called interdigital method is known in which the common electrode of the element is divided into a plurality of interdigital shapes.

The dot matrix type has problems such as complicated connections between drive circuit components and a plurality of lead wires, and lower display performance than segment type liquid crystal display elements due to limited operating margins. On the other hand, the interdigital type does not suffer from the above-mentioned problems and can provide a good multicolor display.

A multi-color liquid crystal display device using an interdigital method is disclosed, for example, in Japanese Patent Application Laid-open No. 136718/1983 (
GO2F 1/133), and detailed explanation will be omitted.

(c) Problems to be Solved by the Invention As mentioned above, the interdigital system is optimal for obtaining a good multicolor display. However, since the multi-color interdigital method described in the above-mentioned Japanese Patent Application Laid-Open No. 59-136718 uses an interdigital shape for the common electrode, the following problems occur.

That is, as described above, since the common electrode has an interdigital shape, its driving method is necessarily a driving method with a duty ratio or higher. As a result, (1) For example, if an interdigital shape is formed by dividing into two parts, the driving method becomes duty driving. It takes,
The driving method is such that a constant voltage is always applied to non-selected electrodes of the interdigital common electrode. Therefore,
When color display is performed, as mentioned above, a certain voltage is also applied to the non-selected electrodes, so there is no selection! There is a problem that the colors of the finest color fill are slightly leaked, and the contrast of the color display is reduced. This problem becomes more serious as the duty drive becomes higher.

■Because the common electrode has an interdigital shape,
An insulator such as an alignment film is arranged in the divided regions of the common electrode divided into an interdigital shape, and a relatively large stray capacitance is generated between the divided regions. Due to this stray capacitance,
There is a problem in that the effective value ratio of the voltage applied to the selected electrode and the non-selected electrode of the common electrode changes, resulting in a significant decrease in display contrast.

■Because the common electrode has an interdigital shape,
When the display area is narrow or when multicolor display is to be improved, it is necessary to form the common electrode pattern extremely thin. As a result, the wiring resistance increases significantly, causing display unevenness, resulting in a problem of deterioration of display quality.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned problems, and includes a pair of glass substrates disposed facing each other, a plurality of segment electrodes being formed on the inner surface of one of the glass substrates, A liquid crystal display device in which a common electrode is formed on the inner surface of the other glass substrate to perform desired segment display, characterized in that the plurality of segment electrodes formed on the one glass substrate have an interdigital shape.

(*) Function According to the invention, by making the segment electrodes into an interdigital shape, it is possible to perform multicolor display using a static drive method, improving display contrast and wide viewing angle multicolor display. It is possible to realize a display device of.

In addition, in the present invention, since the segment electrodes have an interdigital shape as described above, even when forming an interdigital shape in each segment electrode, the pattern length of the routing line is longer than that of the conventional interdigital LCD. It can be made significantly shorter.

(F) Example The liquid crystal display device of the present invention will be described below based on the example shown in FIGS. 1A to 2.

FIG. 1A is a plan view of a segment electrode substrate on which segment electrodes have been formed, and FIG. 1B is a plan view of a common electrode substrate on which a common electrode has been formed facing the segment electrode substrate. (The electrodes are formed on the back side of the common electrode substrate.) FIG. 1C is a partially enlarged view of FIG. 1A, and FIG. 2 is a sectional view when the respective substrates are integrated.

1A to 2, (la) and (lb) are transparent substrates, (2) are segment electrodes formed on the substrate (1a), and (3) are common electrodes formed on the substrate (1b). electrode,
(4) is a light shielding film, and (5) is a color filter layer formed on the segment electrode (1a).

A glass substrate is used as each of the transparent substrates (la) and (lb), and a transparent electrode of a desired shape for performing segment display can be formed on the glass substrate using a transparent electrode material such as indium oxide.

On one transparent substrate (1a), as shown in FIG.
C) is formed in an extended manner. That is, each segment electrode (2) corresponding to the display area is formed in an interdigital shape, forming a figure-eight pattern. This will be explained in further detail using FIG. 1C.

FIG. 1C is an enlarged view of the interdigital shape part of FIG. 1A, and in this example, two electrodes (2a) (2b)
is used to form interdigital. Note that the area indicated by the dotted line is an area where segment display is performed.

On the other hand, a common electrode (3) is formed on the other substrate (1b) as shown in FIG. 1B. The common electrode (3) formed in this example can be formed into a single structure in order to perform static driving, but the common electrode (3) is not limited to a single structure and can be divided into two or more parts. Good too.

Also, on the common electrode (3) there is a figure 8 segment, i.e.
A light shielding film 4) is formed using a metal such as nickel or chromium in the non-display area excluding the display area.

Incidentally, a color filter layer (5) for performing multicolor display is formed on segment electrodes (2) formed in an interdigital shape. More specifically, in the present invention, the color filter layer (5) is formed not only on the interdigital shaped portion of the segment electrode (2) serving as the display area, but also on the wiring line of the non-display area extending from the interdigital electrode. Can be actively formed.

That is, the thickness of the color filter layer (5) is approximately 1.5 to 2.5 mm.
0μ, whereas the transparent electrode of the segment and common electrode has a thickness of 0.1μ, the light shielding film has a thickness of 0.2μ, and the alignment film has a thickness of 0.1μ, making the color filter layer (5) significantly thicker.
In a cell with a cell gap of about 10 μm, there is a large difference in cell gear and size between the area (display area) where the color filter layer (5) is located and the area (non-display area). the result,
Problems such as display unevenness that significantly degrade display quality occur.

However, in the present invention, the color filter layer (5) is arranged not only on the interdigital part of the display area but also on the wiring line of the non-display area, so the above-mentioned problem does not occur, and the color filter layer (5) It is possible to prevent uneven capping due to

Such a color filter layer (5) can be easily formed on the electrode on the substrate (1a) by electrodeposition, for example, forming red (5a) and green (5b) filter layers. .

In addition, an alignment film (not shown) made of polyimide resin or the like is formed on each of the substrates (la) and (lb), and the segment electrodes (2) and common electrodes (3) are arranged to face each other and sealed. They are integrated using adhesives such as materials to form cells. Liquid crystal is injected into the cell using a well-known method, and a predetermined display is performed.

That is, if voltage is applied to the segment electrode for red color, the display will be completely red, if voltage is applied to the segment electrode for green color, the color will be displayed in green color, and if voltage is applied to both electrodes, the mixture of red and green will display yellow color. Multi-color display is possible.

(G) Effects of the Invention As detailed above, according to the present invention, it is possible to provide a liquid crystal display device that performs multi-color display with significantly improved display quality by forming segment electrodes in an interdigital shape. can.

Furthermore, since the present invention includes a light-shielding film, the contrast can be significantly improved compared to conventional products.

Furthermore, in the present invention, the cell gap can be made constant by actively disposing color filter layers in non-display areas other than the display area of the interdigital portion. As a result, display unevenness and the like can be prevented.

[Brief explanation of the drawing]

Figure 1A is a plan view of one board, Figure 1B is a plan view of the other board, Figure 1C is an enlarged view of Figure 1A, and Figure 2 is Figure 1A.
FIG. 3 is a cross-sectional view of FIG. (la) (lb) are transparent substrates, (2) are segment electrodes, (3) are common electrodes, (4) are light shielding films, (5)
is a color filter layer. Rei 1st figure C 2nd figure

Claims (4)

[Claims] (1) In a liquid crystal display device in which a pair of glass substrates are arranged facing each other, a plurality of segment electrodes are formed on the inner surface of one of the glass substrates, a common electrode is formed on the inner surface of the other glass substrate, and a desired segment display is performed. . A liquid crystal display device, wherein the plurality of segment electrodes formed on the one glass substrate have an interdigital shape. (2) The liquid crystal display device according to claim 1, wherein the segment electrode has a figure-eight shape. (3) The liquid crystal display device according to claim 1, wherein the common electrode has a single structure. (4) The liquid crystal display device according to claim 1, wherein the common electrode is divided into at least two parts.