JPH0664276B2 - Liquid crystal display element - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a liquid crystal display device, and more particularly to improvement of display quality of character display by a segment system capable of switching display colors of two or more colors.

[Prior art]

Conventionally, for example, a liquid crystal display element (hereinafter referred to as LCD) for displaying a numeral by a segment system capable of switching three display colors has been shown in FIG. FIG. 1 (a) is a partial perspective view showing the inside by partially cutting away a conventional LCD, and FIG. 1 (b) is a partial sectional view showing the conventional LCD. In the figure, (1a) and (1b) are opposite transparent substrates, (2a) and (2b) ..... (collectively referred to as (2). Similarly, when collectively referred to, numbers and subscripts of alphanumeric characters Is shown by using only) is a segment electrode formed on the inner surface of the transparent substrate (1a), and is composed of a plurality of segments and displays characters or numbers. In the case of numerical display, each displayed digit is divided into seven segments, which are connected to lead wires (not shown). (3) is an interdigital common electrode formed on the inner surface of the transparent substrate (1b) so as to face the segment electrodes (2) and divided into N pieces. In this case, two common electrodes (3a)
(3b) and connected to two lead wires (not shown). The segment electrode (2) and the common electrode (3) are, for example, indium oxide transparent electrodes. (4a) and (4b) are N-color striped transparent colored layers formed in conformity with the interdigital shape on each of the interdigital common electrodes (3). For example, (4a) is on the common electrode (3a). Red colored layer, (4b)
Is a green colored layer on the common electrode (3b). The striped transparent colored layer (4) may be formed by applying a transparent coating material by a screen printing method, a vapor deposition method or the like. In addition, (5) is a liquid crystal layer,
(6) is a sealing material. (7) is an insulating film that separates the colored layer (4) and the liquid crystal layer (5), and is provided for the purpose of preventing the deterioration of the LCD due to the reaction between the liquid crystal and the paint or the dissolution of the paint into the liquid crystal. Note that (100) indicates the entire LCD.

When the LCD (100) is used for display, for example, a twisted nematic liquid crystal layer having a positive dielectric anisotropy is used for the liquid crystal layer (5),
The LCD (100) is sandwiched by two polarizing plates (not shown) so as to be in the extinction state (normally dark state), and this is illuminated from behind the LCD (100) by, for example, a fluorescent lamp. Then, a predetermined voltage is applied to the liquid crystal layer (5) between the segment electrode (2) and the common electrode (3) through the end of a lead wire (not shown). When a voltage is applied, the shape of the segment electrode (2) (hereinafter, abbreviated as a segment pattern) becomes a lighting state, that is, becomes transparent. Therefore, looking at the LCD (100) from the side opposite to the fluorescent lamp, if the common electrode (3a) is selected, the segment pattern is red, if the common electrode (3b) is selected, the segment pattern is green, the common electrode If both (3a) and (3b) are selected, they will be visible in a mixed color of red and green. As a result, if a predetermined segment pattern is turned on, three-color switching numerical display can be performed. That is, with the above-mentioned configuration, it is possible to display characters in N or more display colors for each segment.

FIG. 2 is a schematic view showing the wiring of the common electrode, segment electrode and lead wire of the conventional LCD (100), showing the case of three-digit numeral display. For convenience, the two interdigital common electrodes (3a) and (3b) and their lead wires (8a) and (8b) are routed in solid lines, and each segment electrode (2) is surrounded by the dotted line in the segment pattern. Lines (9a) (9b) …… are shown as dotted lines.

Since the lead wires (8) and (9) of the conventional LCD (100) are routed as shown in FIG. 2, for example, focusing on the center digit, the lead wires (8) and (9) are displayed in the display area. Crossover point (point surrounded by circle) (1
There was a drawback that the abnormal lighting in 0b) (10c) (10e) (10f) (10g) could not be avoided. Similar drawbacks occur not only in the central girder, but every girder. How is this abnormal lighting lead wire (8)
Even if (9) was made thin, it was visually recognized, which was a cause of deterioration in display quality. Furthermore, the wiring distance between the two lead wires (8) of the common electrode (3) generally becomes longer as the number of display digits increases, and the resistance causes the lighting state of the display segments of the upper digit and the lower digit to vary. I was told.

[Outline of Invention]

The present invention has been made to eliminate the above-mentioned drawbacks of the conventional ones. The common electrode is divided into M blocks of M> N + 1, and the lead wires of the segment electrodes are arranged in the gaps between the blocks. By reading out on the opposite surface, the lead wire of the segment electrode and the lead wire of the common electrode are not crossed in the display area, thus eliminating the abnormal lighting and improving the display quality.

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings. Third
The figure is a schematic diagram showing the wiring of the segment electrodes, common electrodes, and their lead wires of the LCD according to one embodiment of the present invention, and shows the case of three-digit numeral display. Now, focusing on the second digit, the common electrode of the interdigital shape is explained.
Divide the lead wire of (3) into four blocks at points (11a) and (11b) (hereinafter referred to as division points) indicated by circles. (Lead wires of each block are shown as (8a-1), (8a-2), (8b-1), (8b-2)) That is, the common electrode (3) is made into M blocks of M> N + 1. If the lead wire (9) of each segment electrode (2) is read out at this split point, that is, on the surface facing the gap between the blocks, the lead wire (9) of the segment electrode and the common electrode The lead wire (8) can be wired without crossing in the display area. In FIG. 3, for convenience, an interdigital common electrode (3) and its lead wires (8a-1), (8a-
2), (8b-1) and (8b-2) are shown by solid lines, each segment electrode (2) is shown by a dotted line surrounding the segment pattern, and the lead wire (9) is shown by a dotted line.

FIG. 4 is an enlarged plan view showing a part of an LCD according to one embodiment of the present invention, and FIG. 4 (a) shows a dividing point (11b).
(b) shows the division point (11a). As an example, when displaying a number of 25 mm (height) × 15 mm (width) with 7 segments of 3 mm (width), the interdigital pitch of the common electrode (3) is designed to be 250 μm and the electrode width is about 200 μm. .
At this time, the width of the dividing point (11) becomes 300 μm, and the lead wires (9) of the segment electrodes (2b) and (2c) are formed on the surface facing the gap.
b), (9c) two, or segment electrodes (2e), (2f), (2
It is sufficient to pass the three lead wires (9e), (9f), and (9g) of g).

The lead wires (8a-1) and (8a-2) and (8b-1) and (8b-2) are connected outside the LCD, for example, on a printed circuit board.

If the common electrode (3) is divided into four blocks as shown in Figs. 3 and 4, there will be no cross points in the display area of the lead wires (8) and (9), and the conventional LCD (100) can The abnormal lighting is eliminated and the display quality is improved. Also, in the lead wire section, the common electrode
Since (3) is divided, the routing distance of each lead wire is shortened, and the variation in the lighting state of the display segment seen in the conventional LCD (100) is reduced.

As described above, the explanation has been made by focusing on the second digit, but the same effect appears in every digit. Further, in the case of the present invention, the number of lead wires (8) and (9) between the digits is seven, which is smaller than that of the conventional nine.
Therefore, there is also an advantage that it is possible to display numbers with a narrower digit space than in the conventional example.

The present invention is not limited to the three-digit display, and its effect can be expected for any number of digits.

Further, in the above-mentioned embodiment, the display of numbers is described, but the same effect can be obtained also by displaying the characters other than the numbers in the segment system with the above configuration.

〔The invention's effect〕

As described above, according to the present invention, the common electrode is M> N +.
Since the lead wire of each segment electrode is read out on the surface facing the gap between the above-mentioned blocks by dividing into M blocks of 1, the lead wire of the segment electrode and the lead wire of the common electrode do not cross each other. Therefore, there is an effect that an abnormal lighting in the display area is eliminated and an LCD with high display quality is obtained.

[Brief description of drawings]

FIG. 1 (a) is a partial perspective view showing the inside by partially cutting away a conventional LCD, and FIG. 1 (b) is a partial cross-sectional view showing the conventional LCD.
FIG. 4 is a schematic view showing an electrode wiring of a conventional LCD, FIG. 3 is a schematic view showing an electrode wiring of an LCD according to an embodiment of the present invention, and FIGS. 4 (a) and 4 (b) are according to an embodiment of the present invention. FIG. 3 is an enlarged plan view showing a part of the LCD. (2) …… Segment electrode, (3) …… Common electrode, (4) …… Transparent colored layer, (8), (9) …… Lead wire, (11) …… Gap between blocks, (100) ...... Liquid crystal display element In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A segment electrode comprising a plurality of segments for displaying characters, an interdigital common electrode which is provided facing these segment electrodes and is divided into N pieces, and each of the interdigital common electrodes. In a case where each of the above-mentioned segments has a transparent colored layer of N colors and character display is performed with a display color of N colors or more for each segment, the common electrode is divided into M blocks of M> N + 1. Then, the liquid crystal display device is characterized in that the lead wire of each of the segment electrodes is read out on the surface facing the gap between the blocks.