JP2921229B2 - Coordinate position input device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate position input device used as a peripheral device of information equipment such as a personal computer and a word processor.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to a coordinate position input device shown in FIG. FIG. 3 is an exploded perspective view of a conventional coordinate position input device.

According to FIG. 3, a shaft 2 is rotatably held on a mounting base 1. A sensor 3 is attached to the shaft 2 and converts the rotation of the shaft 2 into a signal to output a coordinate position. The ball 4 is on the shaft 2 so that it can rotate freely.
The case 5 is held so as to protrude from the center hole of the case 5, and is fixed on the printed circuit board 6.
The mounting base 1, the balls 4 and the case 5 were made of an insulating resin so that static electricity did not pass through.

[0004]

In the conventional coordinate position input device, for example, when the operator is charged, the static electricity is generated between a small gap between the ball 4 and the case 5 or the ball 4.
On the printed circuit board 6 through the surface of the case 5 and the inner wall surface of the case 5 to cause a malfunction of the circuit.

[0005]

According to the present invention, in order to solve the above-mentioned problems, a conductive layer such as a metal electrostatic sheet is formed on the back side of a case of a coordinate position input device. The conductive lands connected to each other are brought into contact with a conductive spring.

[0006]

Therefore, according to the present invention, static electricity is discharged to the conductive land on the printed circuit board through the conductive layer on the back side of the case of the coordinate position input device and the conductive spring, so that malfunction of the circuit can be prevented. is there.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A coordinate position input device according to the present invention will be described with reference to FIGS. FIG. 1 is an exploded perspective view of a coordinate position value input device according to the present invention, and FIG. 2 is a sectional view of the same device.

According to FIG. 1, a shaft 8 is rotatably held on a mounting base 7 and a sensor 9 is mounted on the shaft 8. The rotation of the shaft 8 is converted into a signal to output a coordinate position. . A spring hole 10 is provided through the mounting base 7, and a metal conductive spring 11 is inserted therein. The ball 12 is held on the mounting base 7 by a shaft 8 so as to be freely rotatable, and is covered with a case 14 to which a metal electrostatic sheet 13 is adhered, so that the ball 12 projects from the center hole of the case 14. Is configured.

The mounting base 7 is fixed on the printed circuit board 15. At this time, a conductive land 16 is provided on the printed circuit board 15 directly below the spring hole 10, and the conductive land 16 is connected to the GND pattern 17.

The conductive spring 11 is configured to contact the electrostatic sheet 13 and the conductive land 16. The mounting base 7, the ball 12, and the case 14 are made of an insulating resin so that static electricity does not pass through.

Next, a description will be given of the operation of the present invention for avoiding static electricity. Discharges to the electrostatic sheet 13 on the back side of the case 14, and the discharged static electricity passes through the conductive land 16 on the printed circuit board 15 via the conductive spring 11 to the GN.
Grounded through D pattern 17.

[0012]

According to the present invention, as is apparent from the above embodiment, the static electricity is discharged through the GND pattern with the printed circuit board by providing a conductive layer such as an electrostatic sheet and a conductive spring. The danger of malfunctioning due to discharge to other circuit parts above is prevented.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an embodiment of a coordinate position input device according to the present invention.

FIG. 2 is a sectional side view of the same.

FIG. 3 is an exploded perspective view of a conventional coordinate position input device.

[Explanation of symbols]

 7 Mounting Base 8 Axis 9 Sensor 11 Conduction Spring 12 Ball 13 Electrostatic Sheet 14 Case 15 Printed Circuit Board 16 Conductive Land 17 GND Pattern

Claims (1)

(57) [Claims] At least a shaft rotatably held by a mounting base and having a sensor mounted thereon, a ball rotatably held by the shaft, and a ball mounted so as to protrude from a center hole. A coordinate position input device comprising: a case; a conductive layer provided on an inner wall of the case; and a conductive spring mounted on the mounting base for bridging the conductive layer and a ground portion on a printed circuit board.