JPH04138426A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To allow the simultaneous execution of multicolor display and gradation display with one cell by varying the respective electrode widths of the meshed parts where segment electrodes of interdigital shapes mesh each other and disposing color filters on the segment electrodes. CONSTITUTION:The plural segment electrodes 2 which constitute seven segmented eight are formed to in interdigital shape on one transparent substrate 1a. The electrodes of the interdigital shape are so formed that the respective electrode widths vary from each other in the meshed parts thereof. On the other hand, the common electrodes 3b formed on the other 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 gradation display is executed in various ways even if the number of the division of the interdigital shapes is two.

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 intra-film 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.

(8) Problems to be Solved by the Invention As mentioned above, the interdigital system is optimal for obtaining 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 performing color display, since a certain voltage is also applied to the non-selected electrodes as described above, the color of the color filter on the non-selected electrodes is slightly blurred, reducing the contrast of the color display. There's 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 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 arranged facing each other, and a plurality of segment electrodes formed on the inner surface of each of the glass substrates. In a liquid crystal display device that forms a common electrode in an interdigital shape and performs a desired segment display, the interdigitated segment electrodes engage with each other in the interdigitated portions, each of which has a different electrode width, and a color filter is disposed on the segment electrode. It is characterized by what it did.

(*) Effect As described 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 in one cell.

(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 as each of the transparent substrates (ia) and (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 and constitutes an 80-character 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.

As shown in FIG. 1C, the interdigital electrodes of the present invention are formed so that the widths of the electrodes differ from each other at the occlusal portion. For example, if the electrode width of one electrode (2a) is t and the width of the other electrode is t, then
It must be formed so that t<tl. Each electrode width 1,
1. Any gradation can be selected by changing .

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 formed in an interdigital shape. At this time, the other board (1b)
Interdigital shaped common electrode (3
) are formed so as to be perpendicular to the interdigital shape electrodes of the segment electrodes on one substrate (1a). In this embodiment, the interdigital shape electrode of the common electrode (3) is divided into two parts with the slit (shaded area) as the boundary, as shown in the first diagram, and only the display area part is in the interdigital shape. It is formed. Therefore, if a pair of substrates (1a) and (lb) are produced, segment electrodes (
2) and the common electrode (3), which have interdigital shapes, are arranged so as to be perpendicular 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.

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 chrome 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. To be more specific, in the present invention, the color filter layer (5) is formed not only on the interdigital shaped portion of the segment electrode (2> which becomes the display area) but also on the wiring line of the non-display area extending from the ink digital electrode. 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 gap between the region (display region) where the color filter layer (5) is located and the region (non-display region). 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-mentioned problem does not occur, and the color filter layer (5) It is possible to prevent gap unevenness due to

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

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 a seal is formed. They are integrated using an adhesive such as material to form a cell.Liquid crystal is injected into the cell by 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.

Further, according to the present invention, by making the electrode widths of the occlusal part of the interdigital shape on the segment side different, there is an advantage that a large number of gradations can be displayed even if the number of divisions of the interdigital shape is two. .

[Brief explanation of the drawing]

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.

Claims (1)

[Scope of 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 and a common electrode formed on the inner surface of each glass substrate are formed in an interdigital shape, and a desired segment display is performed. . A liquid crystal display device, characterized in that the interdigitated segment electrodes engage each other with different electrode widths, and a color filter is disposed on the segment electrodes. (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. (4) The liquid crystal display device according to claim 1, wherein the light shielding layer is made of a metal such as nickel or chromium.