JPH04138422A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To improve the contrast of multicolor display by forming segment electrodes and common electrodes to interdigital shapes and disposing light shielding layers in the non-display regions on the common electrodes and in the display regions correspond to the spacings of the interdigital electrodes on the segment side. CONSTITUTION:The respective segment electrodes 2 formed on one transparent substrate 1a are formed to the interdigital shape and constitute seven segmented eight patterns. On the other hand, the common electrodes 3 formed on the other substrate 1b are formed to the interdigital shape as well. The light shielding films 4a are formed in the non-display regions of the common electrodes 3 and the light shielding films 4a are positively formed on the display regions as well. Namely, the light shielding films 4a are so formed as to correspond to the spacings of the segment electrodes 2a which are formed to the interdigital shape. The multicolor display and gradation display are simultaneously executed with one display element in this way and the specified gap is maintained. The unequal gaps are prevented and further, the contrast is improved.

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, as a liquid crystal display element for displaying numbers using a segment method that can switch between two or more display colors (hereinafter referred to as multi-color), the dot Maddox method or the -boat fishing method has been used. A so-called interdigital system is known in which the common electrode of a segmented 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 -
・Paired glass substrates are placed facing each other! In a liquid crystal display device in which 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 display a desired segment display, a plurality of segment electrodes are formed on the one glass substrate. The plurality of segment electrodes 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, and a non-display area on the common electrode is arranged. Further, a light shielding layer is disposed in a display area corresponding to the gap between the interdigital electrodes on the segment side.

(*) 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.

Furthermore, in the present invention, the light shielding layer is disposed not only in the non-display area of the common electrode but also in the display area, that is, the area corresponding to the gap between the interdigital electrodes on the segment side, so that the contrast of multicolor display can be improved. I can do it.

(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 (1g>(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.

As shown in FIG. 1A, one transparent substrate (la) has a plurality of segment electrodes (2
) is formed, and a lead-out line (2c) is formed extending from each segment electrode (2).In other words, 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 formed in an interdigital shape. At this time, the other board (1b)
Interdigital shaped common electrode (3
> is formed so as to be perpendicular to the interdigital shape electrodes of the segment electrodes on one substrate (1a). In this embodiment, the common electrode (3) interdigital shape electrode 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. Therefore, if a pair of substrates (la) and (lb) are formed, 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.

By forming the light shielding film (4) in the non-display area of the common electrode (3), it is possible to improve the contrast between the display area and the non-display area. Furthermore, in the present invention, the light shielding film (4a) is actively formed not only on the non-display area but also on the display area. That is, the light shielding film (4a) is the segment electrode (2>
is made into an interdigital shape and formed to correspond to the gap. At this time, the light shielding film (4a) is replaced by another light shielding film (
Since it can be formed in the same process as 4), it does not cause any problems. By providing this light shielding film (4a), -
The contrast of multi-color display can be improved.

By the way, the color filter layer (5) for performing multi-color display is formed on the segment electrode (2) formed in an interdigital shape.Moreover, in the present invention, the color filter layer (5) is formed in the display area. It is actively formed not only on the interdigital shaped portion of the segment electrode (2), but also on the routing line of the non-display area extending from the interdigital electrode.

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 routing 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 color filter layer (5) can be easily formed on the electrode on the substrate (18) by electrodeposition, for example, red (5a) and green (5b) filter layers are formed. .

Further, an alignment film (not shown) made of polyimide resin or the like is formed on each of the substrates (1a) (tb), and the respective segment electrodes (2) and common electrode (3) are arranged to face each other. They are integrated using an adhesive such as a sealant to form a cell. 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. Moreover, if the segment electrode for red or green and the two common electrodes are selected to be the same, a red display (R゛) brighter than the above (R) (G>),
Green display (Go) can be performed, and if both segment electrodes and two common electrodes are selected, 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.

Furthermore, by increasing the interdigital shape of the segment electrodes and common electrodes to three, four, 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.

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

[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 -] poles, (4) are light shielding films, (5
) is a color fill layer. Go to Figure a Figure 1B

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 plurality of segment electrodes formed on the one glass substrate and a 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, characterized in that a light shielding layer is disposed in a non-display area on the common electrode and a display area corresponding to a gap between the interdigital electrodes on the segment side. (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.