JPH04138420A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To allow multicolor display and gradation display simultaneously with one cell and to maintain a specified cell gap by forming segment electrodes and common electrodes to interdigital shapes and disposing color filters on the electrodes of the interdigital shapes on the segment side. CONSTITUTION:The plural segment electrodes 2 constituting truncated chevron segments are formed to the interdigital shape on the one transparent substrate 1a. On the other hand, the common electrodes 3 formed on the other transparent substrate 1b are also formed to the interdigital shape. Further, the color filter layers 5 for making multicolor display are formed on the segment electrodes 2 formed to the interdigital shape. The multicolor display and gradation display are simultaneously executed with the one display element in this way and the specified gap is maintained. In addition, the unequal gaps are prevented.

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 divided into the dot Madnox method and the segment type. A so-called interdigital system is known in which the common electrode of a liquid crystal display 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, narrow operating margin, and lower display performance than segment type liquid crystal display elements. 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 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 performing color display, since a certain voltage is also applied to the non-selected electrodes as described above, the color of the color fill on the non-selected electrodes is slightly blurred, reducing the contrast of the color display. There is a problem. 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 placed 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, In a liquid crystal display device in which a common electrode is formed on the inner surface of the other glass substrate and a desired segment display is performed, a plurality of segment electrodes formed on the one glass substrate and a common electrode formed on the other glass substrate are provided. The present invention is characterized in that the electrodes have an interdigital shape, and a color filter is disposed on the interdigital shape electrode on the segment side.

(E) Effect As described above, according to the present invention, by forming the segment electrodes and the common electrode into an interdigital shape, it becomes possible to perform multi-color display and gradation display simultaneously in one cell.

Furthermore, since the color filters placed on the interdigital electrodes on the segment side are formed by electrodeposition, they can be placed on other lead lines other than the interdigital electrodes, making it possible to maintain a constant cell gap.

(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 are formed, and FIG. 1B is a plan view of a common electrode substrate on which a common electrode is 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 for each transparent substrate (la>(lb), and a transparent electrode of a desired shape for performing segment display is 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, in the present invention, not only the segment electrodes but also the common electrode (3) formed on the other substrate (1b) are interconnected.
r Form into digital shape. At this time, the other board (1b
) is formed on the interdigitated common electrode (
3) is formed so as to be perpendicular to the interdisicle-shaped electrodes of the segment electrodes on one substrate (1a).

In this example, the common electrode (3) interdigital shape electrode has a slit (shaded area) as shown in the first diagram.
The display area is divided into two parts using the border as a boundary, and only the display area portion is formed in an interdigital shape. Therefore, if a pair of respective substrates (la) and (lb) are produced, the interdigital electrodes of the segment electrode (2) and the common electrode (3) will be arranged so as to be orthogonal to each other.

Further, on the common electrode of the other substrate (1b), a light shielding film (4) is formed using a metal such as nickel or chromium on a non-display area excluding the slit part and the display area part.

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 in the interdigital shaped portion of the segment electrode (2) serving as the display area, but also in the wiring line of the non-display area extending from the interdigital electrode. is also actively formed.

That is, the thickness of the color filter layer (5) is about 1.5 to 2.
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 fill layer (5) significantly thicker.
In a cell with a cell gap of about 10 μm, there is a large difference in cell cap between the area (display area) where the color filter layer (5) is located and the area (non-display area). As a result, problems such as display unevenness that significantly deteriorate the 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 problem does not occur, and the color filter layer (5) It is possible to prevent unevenness caused by gilts.

Such a color filter layer (5) can be easily formed on the electrode of the substrate (la) by electrodeposition. For example, red (5a) and green (5b) filter layers are formed. .

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

For example, if you select a segment electrode for red or green and one common electrode, red display (R) or green display (G
) is performed, and when both red and green segment electrodes and one common electrode are selected, a yellow display of red and green mixture (
Y) can be displayed in multiple colors. Furthermore, if the segment electrodes for red or green and the two common electrodes are selected to be the same, a red display (R') brighter than the above (R) and (G),
A green display (G') can be performed, and if both segment electrodes and two common electrodes are selected, a yellow display (Y'), which is brighter than the above (Y), can be displayed in gradation. That is, in this example, 1
Three-color display and two-tone display can be performed in the same cell.

Further, by increasing the interdigital shape of the segment electrodes and the common electrode to three divisions, four divisions, etc., it is possible to obtain multi-color and gradation display with an even wider range.

(G) Effects of the Invention As detailed above, according to the present invention, by forming the segment electrodes and the common electrode into an interdigital shape, it is possible to perform multi-color display and gradation display simultaneously with one display element. becomes possible.

In addition, by proactively arranging color filters on the display area and non-display area of the segment electrodes, the gap can be kept constant and gilt unevenness can be prevented.

[Brief explanation of drawings]

Fig. 1A is a plan view of one board, Fig. 1B is a plan view of the other board, Fig. 1C is an enlarged view of Fig. 1A, Fig. 1 is an enlarged view of Fig. 1B, Fig. 2 1 is a cross-sectional view of FIGS. 1A and 1B superimposed. (la) (lb) are transparent substrates, (2) are segment electrodes, (3) are common electrodes, (4) are light shielding films, (5>
is a color filter layer. 1.:

Claims (3)

[Claims] (1) 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, and a common electrode is formed on the inner surface of the other glass substrate to perform desired segment display, The plurality of segment electrodes formed on the one glass substrate and the common electrode formed on the other glass substrate have an interdigital shape, and a predetermined color filter is arranged on the interdigital shape electrode on the segment side. A liquid crystal display device featuring: (2) The liquid crystal display device according to claim 1, wherein the color filter is arranged on the segment electrode and a segment routing line extending from the segment electrode. (3) The liquid crystal display device according to claim 1, wherein the color filter is formed by an electrodeposition method.