JPS59209224A - Panel switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a highly reliable panel switch.

Panel swifts have recently been used in conjunction with display screens output from computers. For example, by overlaying a panel switch on the display screen, when you touch a certain character, number, or type on the display screen with your fingertip, this point is electrically connected, and the display screen receives a signal from the external circuit. can be displayed.

In this panel switch, transparent conductive films in a matrix structure are wired on the upper and lower plastic substrates, respectively, and each conductive film provided on one plastic substrate is connected to an external circuit. Therefore, when one side of this panel switch is touched with a fingertip, the upper and lower conductive films are connected at that point, and a signal from an external circuit can be transmitted to the display screen. Such panel switches generally have terminals concentrated on one board to facilitate connection with external circuits, but in this case, the lead wires of the terminals concentrated on one board (Even if a method is adopted in which the lead wires from each conductive film constituting the switch section provided on the other board are electrically connected by hanging or conductive adhesive, etc.).

This conventional connection method has a low yield due to the complicated manufacturing process.''Secondly, the panel switches obtained by this method may have continuity defects or increase the frequency of panel switch use (finger touch). As time goes on, the solder and conductive adhesive bonded between the lower lead wires begin to wear out, and furthermore, the solder and conductive adhesive peel off from the lower lead wires. As a result, there are disadvantages in terms of durability, such as conduction defects occurring between the upper and lower lead wires.

Therefore, an object of the present invention is to provide a panel switch that eliminates the above-mentioned drawbacks, and another object of the present invention is to provide a panel switch that is highly reliable and can be used stably over a long period of time. .

The panel switch of the present invention is a lower part of a transparent panel switch, in which two transparent sheets are arranged with a small distance therebetween, and a key switch is formed with a conductive thin film on opposing surfaces of the transparent sheets. a liquid crystal display section is disposed on the 1- side, and the transparent sheet located on the lower side of the two transparent sheets is attached to a polarizing plate constituting the liquid crystal display section, and the transparent sheet located on the 1- side. A seal spacer made of polyethylene terephthalate film, polyethylene, etc. punched into a frame shape may be arranged between the upper glass substrate constituting the liquid crystal display section, and the periphery thereof may be sealed with an epoxy adhesive. At least one of the conductive thin films is electrically connected to a conductive part of a connecting member that alternately includes conductive parts and insulating parts, and one edge of the connecting member is arranged outside the seal spacer. It has the following characteristics.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a perspective view of a connecting member having alternating conductive parts and insulating parts used in the panel switch of the present invention, FIG. 2 is a perspective view of the key switch part used in the present invention, and FIG. 1 is a cross-sectional view of a panel switch of the present invention.

In FIG. 1, a connecting member 1 (hereinafter referred to as "connecting member 1") is shown which includes conductive parts 2 and insulating parts 3 alternately. This connecting member 1 is preferably a thin film with a width of about 2 mm and is highly flexible. A preferred connection member 1 is, for example, "Heat Seal" manufactured by Nippon Graphite Co., Ltd. In this "heat seal", the insulating part 3 can act as an adhesive by heating. Further, a particularly preferable connection member 1 is ``Zebra Rubber'' manufactured by Toshiku Co., Ltd., for example. The conductive portion 2 contains conductive powder of carbon, silver, copper, iron, aluminum, or the like.

The key switch 9 shown in FIG. 2 includes a lower substrate (lower transparent sheet) 4 and an upper substrate (upper transparent sheet) 5, with a conductive film 6 provided on the lower substrate 4 and a conductive film provided on the upper substrate 5. The film 7 is wired in a matrix structure. Further, it is preferable that the lower substrate 4 is attached to one polarizing plate 8 constituting the liquid crystal display.

The edge of the connection member 1 used in the present invention overlaps the edge of the lower substrate 4, and the conductive film 6 and the conductive portion 2 of the connection member 1 are electrically connected. The pitch between the insulating part 3 and the conductive part 2 formed in the connecting member 1 is smaller than the pitch of the conductive film 6, and the width of each of the conductive part 2 and the insulating part 3 is smaller than the pitch of the conductive film 6.
By making the width smaller than the width of , each conductive film 6 can be connected to an external circuit without shorting.

The upper substrate 5 and the lower substrate 6 are preferably flexible, and generally plastic substrates can be used, and the conductive films 6 and 7 are preferably transparent films.
Generally, indium oxide (■n203) and tin oxide (S'
n OQ ) or ■ An alloy coating of n203 and S n 02 is preferable.

The small distance 10 (approximately 0.1 to 1 mm, preferably approximately 0.3 mm) between the key switches 9 in the switch in the panel shown in FIG. One board 5 constituting 9
It can be formed by arranging the seal spacer 13 described above between them. At this time, one edge of the connecting member 1 is placed outside the seal spacer 13 to facilitate connection with an external circuit.

The liquid crystal display section 11 includes an upper glass substrate 12 on which electrodes 14 are provided.
It has a structure in which a liquid crystal 17 is sealed between a lower glass substrate 16 provided with an electrode 15, and a lower glass substrate 16 provided with an electrode 15.
A polarizing plate 18 and four anti-body members 19 are arranged behind the.

Next, an example of manufacturing the panel switch of the present invention will be shown.

1 example In015%5n02 (hereinafter referred to as 3rITOJ) membrane material polyester film rIO manufactured by Ondai Co., Ltd.
After screen-printing an acid-resistant resist having a pattern that will form a conductive film formed on one substrate as shown in Figure 2 on the ITO film of DTORI (trade name), this is etched with an etching solution of CHCl and FeC4. Etching was carried out by immersing the sample in 11° to 20°C (mixture solution). Next, the resist was peeled off from this film, washed, dried, and then cut into a desired size.

- On the other hand, a polyester film having a conductive film pattern as formed on the lower substrate of FIG. 2 was prepared in the same manner as described above.

Next, a commercially available liquid crystal cell with a back reflector and a back polarizer (EPSON-LD-B2O33, manufactured by Epson Corporation) was used.
After pasting the polarizing plate on the upper glass plate that makes up the
The previously prepared lower polyester substrate was attached with the conductive film facing in the negative direction.

Next, "Heat Seal (trade name)" manufactured by Nippon Graphite Co., Ltd. having a thickness of 75 pLm was cut into 2 mm width pieces, and the ends were placed on the lower polyester film substrate as shown in Figure 2. By heating the top of the heat seal at 180° C. for 20 seconds, one end of the heat seal was preheated and bonded to one end of the lower polyester substrate. At this time, the heat-sealed portion extending above the upper glass substrate of the liquid crystal cell was also heat-bonded at the same time. Next, adhesive "Takelac A-3" manufactured by Takeda Pharmaceutical Co., Ltd. was applied to both sides of a 100 p.
10 (product name), place it on the glass substrate of the liquid crystal cell, and then place the key on the other adhesive surface.
A polyester board was placed on top of the switch and both were glued together. Thereafter, in order to bring the unbonded heat seal into a completely bonded state, it was heated at 180° C. for 20 seconds. Furthermore, the panel Φ switch produced in this manner was heated at 100'C for 30 minutes while being pressurized using a hot press that can press flat and parallel to complete the production of the panel switch.

In order to test the reliability of the panel switch created in this way, we pressed it continuously using a mechanical method and measured how many times a continuity defect occurred.
It was found that no conduction defects were found even after 000 times of pressing.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a connecting member used in the present invention. FIG. 2 is a perspective view of the key switch portion used in the present invention. FIG. 3 is a sectional view of the panel number switch of the present invention. l-111 connection member 2-1--conductive part 3--m-insulating part 4--lower board 5--J-1 board 8.7-
---Conductive film 8.18-----Polarizing plate 9--111 Key switch 1o----1 Small scanning interval 11---1 Liquid crystal display section 12-----Glass substrate 13---- -Seal spacer 14.15---One electrode 16---Lower glass substrate 17---Liquid crystal layer 19---One reflector Patent applicant Canon Corporation

Claims (1)

[Claims] A panel in which a liquid crystal display section is arranged at the bottom of a transparent panel switch, in which two transparent sheets) are arranged with a minute interval between them, and a key switch is formed with a conductive film on the mutually opposing surfaces of the transparent sheets. In a panel switch in which a seal spacer is arranged between the transparent sheet located on the second side and the upper substrate constituting the liquid crystal display section, at least one of the conductive films alternately serves as a conductive part and an insulating part. What is claimed is: 1. A panel switch, which is electrically connected to a conductive portion of a connecting member provided therein, and wherein one insulating portion of the connecting member is disposed outside the seal spacer.