JPS59112330A - Input device of tablet - Google Patents

Abstract

PURPOSE:To extend the life of a plastic conductive material by constituting a contact substrate by a multi-wiring board. CONSTITUTION:Paired contacts are formed on the surface of a contact substrate 1, pressure-sensitive conductive rubber 2 is placed on the paired contacts and then a character plate sheet 3 is placed on the surface. On the surface of the sheet 3, kanji (Chinese character) corresponding to the signals of the paired contact are printed out in accordance with the positions of the paired contacts of the substrate 1. The operator depresses the position of kanji to be inputted on the sheet 3 by using a tablet pen 4. The depression pushes the rubber 2 to the surface of the paired contacts of the substrate 1, so that a conductive state is formed, electric current flows between the paired contacts and an electric signal is generated. Since the contact part is cylindrical surface in this constitution, the life of the conductive rubber can be extended.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a contact board constituting an input switch of a tablet input device or the like.

[Prior art]

Tablet input devices used in word processors, etc., generate electrical signals by pressing a conductive rubber plate onto the surfaces of contacts provided in pairs on an insulating substrate, thereby creating electrical continuity between the pairs of contacts. It happens. The insulating substrate having the contacts is made of a copper-clad laminate, and the steel parts on the surface are selectively etched using photographic technology to form all the contact pairs. In addition, in order to electrically connect both sides of an insulating substrate, a through-hole technique is also used in which a hole is made in the substrate and only that portion is plated with copper. The formed contacts are plated with gold to ensure contact performance and stability. - A multi-conducting rubber plate is provided with a large number of character sections, on which input characters or symbols are printed directly or indirectly, and the contact pairs are arranged corresponding to each character section, thereby making it possible to By pressing any character section on the conductive rubber plate, electrical conduction can be established between the corresponding pairs of contacts.

A pressure-sensitive 4-electric rubber plate is often used as the conductive rubber, and the contact pair and the conductive rubber plate are in light contact.

Such an input device is operated by pressing a conductive rubber plate using a touch pen and pressing it against a pair of contacts. Pressure-sensitive conductive rubber is made of fC41 which contains conductive metal particles dispersed in the rubber, and when pressed, the metal particles come into contact with each other and conduct electricity. Resistance during conduction is dominated by contact resistance between metal grains and between metal grains and contacts, and as the distance between contacts increases, resistance during conduction increases and anxiety, which is the original property of contact resistance, increases. Effects a qualitative increase. In addition, the contact pair formed by etching technology has a sharp edge at the end, which may damage the conductive rubber plate and shorten its lifespan.

[Purpose of the invention]

It is an object of the present invention to overcome these drawbacks and eliminate the spacing between contact pairs (with printed wiring technology, the conductor spacing is approximately 0.5 mm).
4 ms) and to obtain an insulating substrate having a contact pair without sharp edges.

[Summary of the invention]

In the present invention, wiring is performed using multi-wire technology without relying on printed wiring technology. To form a contact pair, the insulation of a portion of the wiring is peeled off to expose the conductor to the surface. Since insulated wires are used for the wiring, the wiring forming the contact pairs can be placed adjacently in parallel. Therefore, compared to the conventional method, the distance between the contact pairs is
It can be made short.

[Embodiments of the invention]

This will be explained below based on the drawings. FIG. 1 is an exploded perspective view of the input device. A contact pair is formed on the surface of a contact board 1, and a pressure-sensitive conductive rubber 2 is placed on the contact pair. Furthermore, a dial sheet 3 is placed on the surface. Kanji characters corresponding to the signals of the contact pairs are printed on the surface of the dial sheet in correspondence with the positions of the contact pairs of the first contact board. The operator uses the tablet ben 4 to press the position of the kanji character to be input on the dial sheet 3. By pressing down, the second pressure-sensitive conductive rubber is pressed onto the contact pair on the first contact substrate, becomes conductive, and causes current to flow between the contact pair. The two-dimensional positions of the contact pairs are determined by an externally provided circuit (not illustrated here), and a code corresponding to the Kanji character is generated.

Next, the first contact board will be explained in detail with reference to FIG. 2. Reference numeral 11 is a base material of the contact board, and a glass-filled epoxy resin plate is used. It has a lip portion shown in 11-1. Reference numeral 12 denotes an adhesive, which is pressed onto the base material 110. 13 is a polyimide insulated wire with a diameter of about 0.15 km.

The 13 polyimide insulated wires are heated by ultrasonic vibrations on the board with the adhesive, so that the adhesive welds.
The glued wire is removed. Polyimide insulated wires are laid in two-dimensional directions, 13-1 and 13-2 show examples of parallel lines in one direction, and 13-3 and 13-4 are laid at right angles to the above direction. An example of parallel lines is shown.

Line group power shown by 13-3 and 13-4! First it is laid down. In the method of laying a multi-wire wiring board, when crossing the lip shown at 11-1 provided on the board or the previously laid insulated wire, it is laid along them.

After the installation is completed, the curved surface portions are polished using a buff. By polishing, the insulation of the polyimide insulated wire covering the protruding portion 11-1 is peeled off, and the conductor is exposed.

The exposed conductor portions are plated with gold to a thickness of approximately 5 μm by chemical treatment.

Through the above processing, contacts are formed on the contact substrate. The electrical circuit of the contact board is as shown in Figure 3, and the stain signal is generated when the contact pairs at the intersections of the two-dimensional matrix are closed by pressure-sensitive conductive rubber. Become.

The base material of the contact board 11 does not necessarily have to be an insulating plate. Since polyimide insulated wires are used, insulation between the wires can be maintained even if iron plates are used. If an iron plate is used, it can also be used as the lower casing of the case that houses the tablet dial, which was conventionally required to maintain the flatness of the contact board, and the device can be manufactured at low cost.

Although pressure-sensitive conductive rubber is used as an example of the second plastic conductive material in the embodiment, other materials such as conductive rubber may be used. However, since the conductive rubber is lightning conductive, it is not necessary to place it directly on the contact board, but instead it is necessary to insert a spacer with an opening only at the contact pair between the conductive rubber plate 2 and the contact board 1.

〔Effect of the invention〕

In the contact board formed by the multi-wire wiring board in this manner, it is possible to reduce the distance between the contacts of the contact pair. That is, the polyimide insulated wires can be juxtaposed in contact with each other, and the distance between the contact points can be reduced to 0.1 m or less by increasing the peeling surface area of the insulation portion by puff polishing.

This has the effect of reducing variations in operating sensitivity when pressure-sensitive conductive rubber is used. On the other hand, contacts made from printed wiring boards have sharp edges, which reduces the lifespan of the conductive rubber plate.However, according to the present invention, since the contact part has a cylindrical surface, the lifespan of the conductive rubber can be extended. Can be done.

[Brief explanation of the drawing]

FIG. 1 is an exploded view of a tablet input device according to an embodiment of the present invention, FIG. 2 is a detailed partial view of a contact board, and FIG. 3 is a circuit diagram. l...Contact board, 2...Pressure-sensitive conductive rubber, 3...Dial sheet. Agent Patent Attorney Akio Takahashi' No. 10, No. 2, No. 5

Claims (1)

[Claims] 1. When the electric wires are stretched close to each other on the plate surface, the contact plate and the plastic conductive material are used to form the contact, and it operates by the plastic conductive material closing both electrodes of the contact pair when an external force is applied. A tablet input device featuring: