JPS631336Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a liquid crystal display device. More specifically, plastic plates are used for the two upper and lower electrode substrates that form the liquid crystal cell, and a flexible wiring board is used for the drive circuit substrate, and the electrode substrates and circuit board are made to have a specific structure to increase the display area. The present invention also relates to a liquid crystal display device in which a wide space for arranging drive circuit components can be secured.

A liquid crystal display device displays numbers, symbols, etc. by applying a voltage to a liquid crystal layer sandwiched between two upper and lower substrates each having an electrode pattern on its inner surface.The liquid crystal panel used in a conventional liquid crystal display device As an example, a structure as shown in FIG. 1 is known.

That is, FIG. 1 is a schematic cross-sectional view showing the liquid crystal display device portion of an electronic wristwatch. The liquid crystal display panel is made of a glass plate coated with a polarizing plate 1 on the surface thereof, and an upper electrode substrate 2 with a transparent electrode pattern 3 provided on the inner surface.
, a lower electrode substrate 8 made of a glass plate having a transparent electrode 6 on its inner surface and coated with a polarizing plate 1a on its outer surface, and an adhesive layer 4 functioning as a spacer.
Accordingly, a liquid crystal layer 5 is provided in the gap formed between the upper and lower electrode substrates 2 and 8, and an IC case 10 that houses a reflector 9 and an IC 11 located under the lower polarizing plate 1a is further arranged. , a conductive rubber 7 for continuity is placed between the transparent electrode pattern 3 of the upper electrode substrate 2 and the lead wire 12 on the circuit board 13, and this is attached to the watch body 14 by a screw 16 using a support frame 15. has been fixed through.

By the way, in the liquid crystal display panel having the above structure, since the adhesive layer 4 and the conductive rubber 7, which function as spacers, surround the periphery of the upper electrode substrate 2 with a certain width, the liquid crystal display area is reduced accordingly. There is a drawback that the conductive rubber 7 sometimes acts as a blind spot for the viewer. Further, as mentioned above, the upper and lower electrode substrates 2 and 8 are made of glass plates, and therefore have the disadvantage of being easily broken by impact.

In order to eliminate such drawbacks of the conventional example, for example, as shown in FIG. An upper transparent electrode pattern 3 and an upper transparent electrode 6 are provided on the contacting inner surfaces, and
A liquid crystal layer 5 of a lower electrode substrate 8 which forms a vertical frame 2a by bending the periphery of the upper electrode substrate 2 substantially vertically downward, and forms a liquid crystal layer 5 filled with liquid crystal within the frame via an adhesive layer 4. A polarizing plate 1a and a reflective plate 9 are coated on the opposite side, and a rectangular frame-shaped conductive rubber 7 is disposed to support the reflective plate 9 and to be located at the periphery of the display pattern. Upper transparent electrode pattern 3 of upper electrode substrate 2 on outer surface of rubber 7
, the inner surface is in contact with the IC case 10, and the lower surface is in contact with the lead wires 12 of the IC 11 disposed on the circuit board 13, so that the IC 11 and the upper transparent electrode pattern 3 are electrically connected. A display device has been proposed.

Although such a structure can eliminate the drawbacks of the conventional example shown in FIG. The space in which circuit components can be placed is extremely narrow due to the rubber 7 and the IC case 10, and there is little freedom in placement.Also, if the circuit components are placed below the circuit board 13, the degree of freedom in placement increases;
The drawback was that the clock module was thicker.

In this invention, the upper and lower electrode substrates are made of plastic plates.
In addition, the circuit board is made of a flexible wiring board, and the peripheral edges of the upper electrode board and the circuit board are each bent vertically downward to provide a vertical frame, and the lower electrode board and the circuit board are placed within the vertical frame of the upper electrode board. A liquid crystal display in which the above-mentioned drawbacks of the conventional liquid crystal display are eliminated by fitting the vertical frame of the upper electrode substrate and the vertical frame of the circuit board so that the upper transparent electrode and the driving circuit are electrically connected. The aim is to provide the equipment.

Hereinafter, the present invention will be explained based on drawings showing one embodiment. Fig. 3 is a schematic cross-sectional view when applied to an electronic wristwatch, 2 is an upper electrode substrate, 8 is a lower electrode substrate, both of which are made of plastic plates, e.g. It consists of a film molded product made of polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, etc., and the inner surface in contact with the liquid crystal layer 5 described later is coated with a transparent film made of indium oxide, tin oxide, etc. by known means. A conductive film, namely an upper transparent electrode pattern 3 and a lower transparent electrode 6, is provided. Further, while the upper electrode substrate 2 is coated with the polarizing plate 1 on its surface, the periphery is bent downward almost vertically as shown in the figure to form a vertical frame 2a, and within the frame there is a fixed thickness provided on the periphery. A lower electrode substrate 8 forming a liquid crystal layer 5 filled with liquid crystal is fitted through an insulating adhesive layer 4 which acts as a spacer having a thickness.
1a is a polarizing plate coated on the surface of the lower electrode substrate 8 opposite to the liquid crystal layer 5, and 9 is a reflecting plate coated on the polarizing plate 1a, which is composed of, for example, an acrylic resin plate coated with aluminum.

13 is a circuit board for configuring the drive circuit;
For example, it is made of a flexible wiring board made of polyimide film, polyester film, etc., and has lead wires 12 made of a conductive material constituting a circuit pattern on the surface, and the periphery is bent downward almost vertically as shown in the figure, forming a vertical frame. 13a
, and the vertical frame 13a is connected to the upper electrode substrate 2.
A pressure frame 1 having a circular cross section overlaps with the inner end of the vertical frame 2a and has an inner surface arranged in the shape of a rectangular frame, for example.
7, the end portion 3a of the upper transparent electrode pattern 3 and the lead wire 12 of the circuit board 13 are pressed together and electrically connected, and the upper surface of the circuit board 13 is pressed by the reflector plate 9.
The reflector plate 9 is disposed in close contact with the reflector plate 9 to support the reflector plate 9. Further, the IC case 10 containing the drive circuit IC is disposed approximately in the center of the circuit board 13, passing through the circuit board 13, and each terminal is in direct contact with the lead wire 12 of the circuit board 13 for conduction. Reference numeral 15 denotes a support frame to which the liquid crystal display panel is fixed to the watch body 14 via screws 16, and which connects the upper surface of the watch body 14 and the circuit board 1.
3, that is, inside the pressure frame 17, a space 18 is created, and external circuit components such as a capacitor (not shown) are disposed within the space 18.

Therefore, the conductive rubber that was conventionally used to establish continuity between the transparent electrode and the drive circuit can be removed, making it possible to secure a larger space for arranging circuit components, and to replace the circuit board with a polyimide film. Since it is constructed from a flexible wiring board made of a thin material such as, it is possible to secure a wide space in the thickness direction.

As described above, the present invention provides a liquid crystal display panel in a liquid crystal display device in which the upper and lower electrode substrates are made of plastic plates, the driving circuit board is made of a flexible wiring board, and the peripheral edge of the upper electrode substrate and the circuit board is made of a plastic board. are bent vertically downward to form a vertical frame, the lower electrode board and the circuit board are fitted into the vertical frame of the upper electrode board, and the vertical frame of the upper electrode board and the vertical frame of the circuit board are overlapped. Since the upper transparent electrode and the drive circuit are connected to each other, a large space for placing circuit components can be secured, increasing the degree of freedom in placing circuit components, and creating a more reliable liquid crystal display device. It is effective in providing

[Brief explanation of the drawing]

Figures 1 and 2 are schematic cross-sectional views of main parts of a conventional liquid crystal display device attached to an electronic wristwatch, respectively;
FIG. 3 is a schematic cross-sectional view of essential parts of the liquid crystal display device of the present invention attached to an electronic wristwatch. 1, 1a...Polarizing plate, 2...Upper electrode substrate, 3
... Upper transparent electrode pattern, 4 ... Adhesive layer, 5 ...
...Liquid crystal layer, 6... Lower transparent electrode pattern, 8...
Lower electrode board, 9...Reflector, 10...IC case, 12...Lead wire, 13...Circuit board, 14
...Watch body, 15...Support frame, 16...Screw, 17...Pressure frame, 18...Circuit component arrangement space.

Claims (1)

[Claims for Utility Model Registration] 1. In a liquid crystal display device consisting of a panel in which a liquid crystal material is filled between two upper and lower electrode substrates each having a transparent electrode on the inner surface, both of the electrode substrates are made of a plastic plate, and a driving circuit is provided. The board is made of a flexible wiring board, and the peripheral edges of the upper electrode board and the circuit board are each bent vertically downward to provide a vertical frame, and the lower electrode board and the circuit board are arranged within the vertical frame of the upper electrode board. 1. A liquid crystal display device characterized in that the upper transparent electrode and the driving circuit are electrically connected by fitting the upper transparent electrode to the circuit board and overlapping the vertical frames of both the upper electrode substrate and the circuit board. 2. Utility model registration where the plastic board is polyethylene terephthalate film, polybutylene terephthalate film, polyether sulfone film, or polycarbonate film, and the base material of the flexible wiring board is polyimide film or polyester film. A liquid crystal display device according to claim 1.