JPS5846450Y2 - liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal display device, and particularly to a small liquid crystal cell used in electronic wristwatches and the like that can be effectively replaced.

It is believed that the lifespan of liquid crystal cells is essentially limited, not only now but also in the future. Therefore, it is desirable to be able to easily replace the liquid crystal cell.

However, a liquid crystal cell has a large number of lead electrodes, and it requires a very difficult technique to make reliable electrical contact with a printed circuit board, ceramic substrate, or the like containing a drive circuit for the liquid crystal cell.

Therefore, in general, there is currently no structure in which the lead electrodes of the liquid crystal cell are directly bonded to the wiring conductors of the substrate using a conductive contact agent to make the liquid crystal cell replaceable.

This trend is particularly prevalent in electronic wristwatches, electronic desk calculators, and other devices that use small liquid crystal cells.

The present invention uses a columnar connector made of laminated conductive rubber and insulating rubber to effectively replace liquid crystal cells.

An embodiment of the present invention will be described below with reference to the drawings.

The embodiment is a liquid crystal display device incorporated into an electronic wristwatch.

As shown in FIGS. 1a and 1b, the liquid crystal cell 1 includes a liquid crystal (not shown) sealed between two transparent glasses 2 and 3, and a lead electrode 4 on the bottom surface of the first transparent glass 2. ,4. . . , and a reflective plate 5 is arranged on the lower surface of the second transparent glass 3.

As is clear from Figure 1a, the minute digit display M1, the 10 minute digit display M10-, the hour digit display H1 button and the 10 hour digit display HIO are displayed in numbers, and the second digit display S has two blinking dots. It is done by displaying it.

Segment: Minute digit display M1.10 Minute digit display M 10%
7 hour digit display H1 each, 10 hour digit table display 1ok
and one second digit display S, for a total of 24 including one common to all, and lead electrodes 4, 4 . . . . is divided into two halves on both sides as shown in Figure 1, and 24 pieces are derived.

FIG. 2 shows a rectangular prism-shaped connector 8 in which conductive rubber 6 and insulating rubber 7 are laminated.

This connector 8 is made by, for example, stacking conductive rubber plates 6' and insulating rubber plates 7' alternately as shown in FIG. It consists of

In the case of FIG. 3, a conductive rubber plate 6' and an insulating rubber plate 7' are sufficiently large for the height H and width B of the connector 8.
This structure is useful because it can be easily produced and a large number of connectors 8 can be cut out using the - structure.

FIG. 4 shows that the liquid crystal cell 1 and the printed circuit board 9 are electrically connected using the connector 8.

The connectors 8, 8 connect the conductive rubber 6 part to the liquid crystal cell 1.
The liquid crystal cell 1 is disposed between the liquid crystal cell 1 and the printed circuit board 9 so as to face each of the lead electrodes 4 buttons and the wiring conductor 10 made of printed metal foil on the printed circuit board 9.

The holding covers 11.11 each have one end connected to the lead electrodes 4, 4.1 of the liquid crystal cell 1. It is secured to the edge of the rain upper surface of the first transparent glass 2 corresponding to ..., and the other end is secured with an appropriate number of setscrews 12,
12. It is attached to the printed circuit board 9 via...

By means of this holding cover 11.11, the liquid crystal cell 1 and the printed circuit board 9 are fixed under mutual pressure, with the connectors 8, 8 sandwiched between them.

As is clear from FIG. 2, in the connector 8 in this embodiment, the conductive rubber 6 portion does not protrude beyond the insulating rubber 7 portion.

Therefore, the connector 8 is connected between the liquid crystal cell 1 and the printed circuit board 9.
When crimped, the conductive rubber 6 and the insulating rubber 7 are joined and integrated as a whole, and the part other than the conductive rubber 6, that is, the insulating rubber 7 part also comes into contact with the liquid crystal cell 1 and the printed circuit board 9, so that the conductive rubber 6 and the insulating rubber 7 are bonded. The contact pressure applied to the elastic rubber 6 portion is weak, and a large pressure is required to obtain a good electrical connection.

This tendency becomes stronger as the width B1 in FIG. 2, in other words, the width corresponding to the portion that contacts the liquid crystal cell 1 and the printed circuit board 9 becomes larger.

According to actual measurements, when the height H shown in FIG. 2 is 2rran, a vertical columnar body with a width B of about 0.8w is appropriate.

With this dimension, it is possible to obtain a contact resistance of Ω±50% for each lead electrode 4 and wiring conductor 10.

Furthermore, it has been proven that a design with a compression ratio of 20% to 30% relative to the height H can withstand long-term use; You can get the pressure to crimp it.

Incidentally, when the width B of the connector 8 is as small as 0.8 mm as described above, a more effective liquid crystal display device can be obtained by the following procedure.

FIG. 5 shows a framework 13 for supporting the connector 8.

The frame 13 is provided with an insertion hole 14 through which the connector 8 is inserted, and mounting holes 15 and 15.

FIG. 6 shows that the liquid crystal cell 1 and the printed circuit board 9 are electrically connected using the frame 13 and the connector 8.

In FIG. 6, the connector 8 is connected to the insertion hole 14 of the framework 13.
The deformation of the connector 8 is restricted by the frame 13 and supported more stably and accurately.

In addition, the insertion hole 14 is designed with an appropriate dimensional play, so that the pressure from above is distributed to the left and right sides, and the compression ratio can be set to 30% to 40% with an appropriate pressure.

Each contact resistance is 3Ω±50% as in FIG.

Although not shown in FIG. 6, in the installation shown in FIG.
determine the position of

Further, in FIG. 6, the same reference numerals as in FIG. 4 indicate the same functions as in FIG. 4.

Normally, each contact resistance of the liquid crystal cell 1 only needs to be several 10K ohms or less, and in the above example, 3 ohms plus or minus 50 ohms or more can be set as well, and the variation in each contact resistance is 50 ohms or less.
It can be suppressed to a small range of 0%, and does not cause any trouble to the electrical connection between the liquid crystal cell 1 and the printed circuit board 9.

To replace the liquid crystal cell 1, use the setscrews 12, 12. ...Remove the presser foot cover 11.11
This can be easily done by removing the .

As described above, according to the present invention, the connector is composed of a simple columnar body made by laminating conductive rubber and insulating rubber, and it is possible to easily obtain a connector with excellent dimensional accuracy in a small size, such as an electronic wristwatch, etc. It is possible to provide an effective button on a small liquid crystal display device incorporated in an electronic desktop calculator or the like.

The original idea is to alternately stack conductive rubber plates and insulating rubber plates, and then join them to a height of H1 width BV? This type of connector has the advantage of being able to easily produce stacked structures and cutting out a large number of connectors from one structure. (the part does not protrude from the insulating rubber part), but in this invention, the width B
The connector is made small and placed in the form of a vertically long columnar body between the lead electrode part of the liquid crystal cell and the wiring conductor part of the circuit board.Even though the cut surface is flat, by applying appropriate pressure to the whole, Good contact resistance can be obtained by applying sufficient pressure to the conductive rubber portion of the connector.

Furthermore, a support member such as a frame is provided between the liquid crystal cell and the circuit board, and the connector is inserted with dimensional play to support its placement, and the pressure from above is dispersed to the left and right within the play. This makes it possible to accurately support such a vertically columnar connector along the lead electrodes of the liquid crystal cell and the wiring conductors of the circuit board, and also eliminates uneven pressure on each part, making it extremely useful. .

[Brief explanation of drawings]

Figures 1a and b are perspective views of a liquid crystal cell of an electronic wristwatch used in an embodiment of the present invention, viewed from above and below; Figure 2 is a perspective view of a connector used in an embodiment of the present invention; Figure 3; is a perspective view for explaining one manufacturing process of the connector shown in FIG. 2, and FIG. 4 is a sectional view showing an example of the basic configuration of the present invention.
FIG. 5 is a perspective view of a framework used in an embodiment of the present invention, and FIG. 6 is a sectional view showing an embodiment of the present invention. 1...Liquid crystal cell, 4,4. ...Lead electrode, 6°6, ...Conductive rubber, 7,1.・・・
...Insulating rubber, 8.8. ...Connector, 9...Printed circuit board, 10.10.・・・・・・
... Wiring conductor, 11, 11.・・・・・・Presser foot cover
13...Framework.

Claims (1)

[Scope of utility model registration request] Conductive rubber plates and insulating rubber plates are stacked alternately, and then they are joined and cut out with a height H1 width B, and the cut out surface is a flat surface, and the middle B is made smaller to make it vertically long. A columnar connector is arranged between the lead electrode part of the liquid crystal cell and the wiring conductor part of the circuit board that face each other in parallel, a support member is provided to support the arrangement, and the connector is placed in the groove formed by the support member. Insert a vertical columnar connector with some dimensional play, apply pressure between the liquid crystal cell and the circuit board, and connect the lead electrodes of each liquid crystal cell and the circuit board through the conductive rubber part of the connector. A liquid crystal display device characterized by electrically connecting wiring conductors.