JP2616540B2 - Sheet-shaped composite switch and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite switch having a wraparound prevention function and a method of manufacturing the same. Keyboards (composite switches) composed of a plurality of switches in a matrix are widely used as input media for various types of industrial and consumer information processing devices. Mock input may occur.

2. Description of the Related Art FIG. 4 is a basic circuit diagram of a keyboard, and FIG. 5 is a circuit diagram of a keyboard in which a diode is connected to each switch to prevent signal wraparound. In FIG. 4, 1 is 4 ×
Reference numeral 4 denotes a keyboard circuit in which a switch 2 is provided, 3 denotes a wiring in a row direction, and 4 denotes a wiring in a column direction. When the switches 2a, 2b and 2c are simultaneously turned on by a key operation, a wiring 3b
Through the switch 2b, the middle part of the wiring 4a, the switch 2a, the middle part of the wiring 3a, and the switch 2c, a sneak signal current flows as if the switch 2d were turned on. In FIG. 5 in which the same reference numerals are used for the same parts as in FIG. 4, the keyboard 5 is composed of switches 2 arranged in 4 × 4.
Are connected to the wiring 3 via the diode 6. Therefore, the sneak signal current is blocked by the diode 6a interposed between the switch 2a and the wiring 3a, so that the wirings 3 and 4
Becomes conductive only by a key operation with the switch 2 that directly connects between them. In the conventional keyboard described above, a diode is disposed together with a switch to prevent signal current from sneaking. In a keyboard using a mechanical switch or a reed switch as the switch, the diode is mounted on a printed wiring board on which the switch is mounted. Was also installed. In recent years, following the trend toward lower prices for keyboards,
Sheet-type composite switches (commonly known as membrane switches), which are simple keyboards with excellent mass productivity, have come to be used. However, a pair of flexible insulating sheets is provided with switching contacts and their wiring conductors. In a sheet-shaped composite switch in which a pattern is formed by a printing means and laminated via a flexible insulating spacer having a through hole in a portion facing the contact, there is a disadvantage that the above-described wraparound preventing diode cannot be mounted. FIG. 6 is an exploded perspective view showing a conventional configuration example of a sheet composite switch (sheet keyboard), and FIG. 7 is a side sectional view of the switch. 6 and 7, a composite switch 11 includes a polyester sheet (first insulating sheet) 12 having a plurality of (four in the figure) conductor layers 13 formed as patterns in the row direction on the upper surface thereof, and a plurality of strips (first insulating sheet). Is an article 4)
A polyester sheet (a second insulating sheet) 17 in which a plurality of (four in the figure) conductor layers 18 as pattern wirings are patterned on the lower surface of the spacer 14 of a polyester sheet with a gap 16 opened. It is. Where 13a in the figure
And 18a are contact points. One end of the conductor layer 13 having the contact (fixed contact) 13a connected in the row direction and the conductor layer 18 having the contact (movable contact) 18a connected in the column direction are polyester sheets 12, 17 respectively.
Of the connector part 12a or 17a. The vertically opposed contacts 12a and 18a coincide with the circular bulge 15 of the through hole 16 formed in the spacer 14.

A sheet-like composite switch 11 in which a plurality of switch elements are integrally formed as described above.
, The movable contact 18a selected from above the seat 17
Is pressed by a finger or the like, the contact 18a is
Contact 13a. Next, when the pressing force is removed, the pressing contact 18a is restored by the elastic restoring force of the sheet 17 itself. Was considered impossible.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems simply and without impairing the characteristics of the existing sheet-type composite switch, such as the flexibility of the sheet-type composite switch. An object of the present invention is to provide a new configuration of a sheet-shaped composite switch having a built-in wraparound prevention function at the time of multiple operations and a simple manufacturing method thereof.

According to the present invention, in order to achieve the above object, a plurality of wiring conductors and a plurality of fixed contacts connected to each of the wiring conductors are provided on an upper surface of one insulating sheet. A sheet-like composite switch having the other insulating sheet having a plurality of movable contacts on its lower surface via insulating spacers having through-holes corresponding to the respective fixed contacts. A predetermined resistance element is integrally formed on the same insulating sheet surface in a connection path between the fixed contact and the wiring conductor on one insulating sheet. Further, the one fixed contact-side insulating sheet simultaneously prints the fixed contacts and the wiring conductors on the upper surface thereof in a predetermined pattern obtained by cutting the connection paths, and connects the cut connection paths. The process is characterized by including a step of printing and forming a resistive layer to be a resistive element in a predetermined pattern.

According to the present invention, not only the contact and wiring are patterned on the insulating sheet of the sheet-shaped composite switch by printing, but also the resistive elements for preventing the wraparound are formed on the same sheet by printing. In addition, a wraparound function can be provided without impairing the thin characteristics of the conventional sheet-shaped composite switch. In addition, since the resistance element is formed on the fixed contact side, the resistance due to vibration at the time of pressing down is small, and a stable resistance value can be maintained for a long time.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a circuit diagram showing a switch matrix configuration of a sheet composite switch according to an embodiment of the present invention. FIG. 1 is an exploded perspective view of the sheet composite switch according to the embodiment based on the circuit diagram. It is the expanded sectional view which cut the switch element part of the compound switch. In FIG. 2 in which the same reference numerals are used for the same parts as in FIG. Therefore, when the switches 2a, 2b, and 2c are simultaneously turned on by a key operation, the potential Vi1 is applied to the wirings 3b and 4b by wraparound as described with reference to FIG. On the other hand, when only the switch 2d is turned on, the potential Vi2 flowing through the switch 2d and the resistor 7 in series with the switch 2d is applied to the wirings 3b and 4b. While the electric current flows, the electric path of the electric potential Vi2 has one resistor 7. Therefore, Vi2> Vi1, and the signal level difference is detected by the circuit logic, and the sneak signal can be easily removed. In FIG. 1 in which the same reference numerals are used for the same parts as in FIG. 6, the composite switch 21 has a polyester sheet 22 on which a plurality of (four in the figure) row-direction wiring conductor layers 24 and the like are patterned on the upper surface. The spacer 14 and the other polyester sheet 17 are laminated. On the upper surface of the one sheet 22, a plurality of (four, 4 × 4, 16) fixed contacts 23 respectively facing the movable contacts 18a formed on the lower surface of the other sheet 17 are clearly shown. It has a wiring conductor layer 24 spaced apart from each fixed contact 23 in a plane and a connection branch path portion 26 between them, and a resistance layer 25 serving as a resistance element is formed in the connection branch path portion 26 by printing means. And one end of each wiring conductor layer 24 is
Collected at 22a. In this case, the resistance layer 25 for each fixed contact 23 is arranged so as to face in the same direction as shown in the drawing, so that an error in the resistance value due to the difference in the direction does not occur when printing the resistance layer. When the sheet 22, the spacer 14 and the sheet 17 are laminated, as shown in FIG. 3, the movable contact 18a and the fixed contact 23 are vertically opposed in the circular through hole 15 of the spacer 14, and are depressed by operating a key (not shown). The movable contact 18a comes into contact with the opposed fixed contact 23, and when the pressing force is removed, the movable contact 18a is separated by the elastic restoring force of the sheet 17 itself. In the manufacturing method, a resistive layer 25 is patterned on the upper surface of the sheet 22 by screen printing in FIG. Then, the fixed contact 23 and the wiring conductor layer 24 which are separated from each other in a plane are patterned so as to be connected on the same insulating sheet surface via a resistance element. Contrary to the above, the fixed contact 23 and the wiring conductor layer 24 may be patterned by printing, and then the resistive layer 25 may be patterned by printing so that the resistive layer 25 partially overlaps at the end. Therefore, when the switch 21 configured in the circuit shown in FIG. 2 is used by connecting the output end of the wiring conductor 3 or 4 to the circuit logic, the switch 21 is the same as the composite switch 11 in which a diode is provided for each switch element. To work. The present invention is not limited to the above embodiment, and is effective when applied to, for example, a sheet-shaped composite switch in which several tens or more switches are arranged in a matrix.

As described above, according to the present invention, not only the wraparound of the sheet-shaped composite switch, in which the wraparound diode for the electric signal could not be mounted, can be prevented, but also the resistance element is formed on the fixed contact side Therefore, a stable resistance value can be obtained over a long period of time, and the effect of simple configuration is extremely large.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a sheet-type composite switch according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a switch matrix configuration of the sheet-like composite switch according to one embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view of a switch element section of the switch shown in FIG.

FIG. 4 is a basic circuit diagram of a keyboard.

FIG. 5 is a basic circuit diagram of a keyboard provided with a wraparound diode.

FIG. 6 shows a sheet composite switch (sheet keyboard).
FIG. 4 is an exploded perspective view showing a conventional configuration example of FIG.

FIG. 7 is a side sectional view of the composite switch shown in FIG. 6;

[Explanation of symbols]

 1, 5, 11, 21: Composite switch 2: Switch element (keyboard) 3, 4, 13, 18, 24: Wiring conductor layer 7, 25: Resistor element 12, 22: Polyester sheet (first insulating sheet) 13a , 23: Fixed contact 14: Spacer 15: Through hole 17: Polyester sheet (second insulating sheet) 18a: Movable contact 26: Branch path for connection

Claims (2)

(57) [Claims] A plurality of wiring conductors and a plurality of fixed contacts connected to each of the wiring conductors are provided on the upper surface of one insulating sheet, and a through hole corresponding to each of the fixed contacts is provided. In the sheet-shaped composite switch having the other insulating sheet 17 provided with a plurality of movable contacts 18a on the lower surface thereof via the insulating spacer 14 provided with the fixed contact 15 on the one insulating sheet 22 on the fixed contact side, A sheet-shaped composite switch, wherein a predetermined resistance element 25 is integrally formed on the same insulating sheet surface in a connection path between a contact 23 and a wiring conductor 24. 2. A plurality of wiring conductors 24 and a plurality of fixed contacts 23 connected to each of the wiring conductors 24 on an upper surface of one of the insulating sheets 22, and a through hole corresponding to each of the fixed contacts. In a method of manufacturing a sheet-shaped composite switch having the other insulating sheet 17 provided with a plurality of movable contacts 18a on the lower surface via an insulating spacer 14 provided on the lower surface, the one insulating sheet 22 is provided on the upper surface thereof. A step of simultaneously printing and forming the fixed contact 23 and the wiring conductor 24 in a predetermined pattern obtained by cutting the connection path thereof; and forming a resistive layer serving as the resistance element 25 in a predetermined pattern connecting the cut connection path. A method for manufacturing a sheet-shaped composite switch, wherein the method is performed including a step of forming a print.