Key sheet for pointing device and pointing device

• US 20050264530A1
• Filed: 05/27/2005
• Published: 12/01/2005
• Est. Priority Date: 06/01/2004
• Status: Active Grant

• Current Assignee: Asahi Kasei EMD Corp (Asahi Kasei Corporation), Polymatech Company Limited
• Original Assignee: Asahi Kasei Electronics Co., Ltd. (Asahi Kasei Corporation), Polymatech Company Limited
• Inventors: Honmatsu, Yoshifumi, Takatsuka, Toshinori
• Granted Patent: US 7,508,376 B2
• Time in Patent Office: Days
• US Class Current: 345/160
• CPC Class Codes: G06F 3/0338 with detection of limited linear or angular displacement of an operating part of the device from a neutral position, e.g. isotonic or isometric joysticks

Abstract

Provided is a pointing device that can be reduced in thickness even if a magnetic field sensor is mounted to a front face of a printed circuit board. When a support portion laterally moves, a reverse face of a flexible portion is displaced while being guided away from the printed circuit board due to deformation of a mountain fold flexure portion as a directional deformation portion. Therefore, a clearance between the reverse face of the flexible portion and the printed circuit board increases, and the magnetic field sensor can be mounted to the front face of the printed circuit board, thereby making it possible to reduce thickness of the pointing device. At the same time, the flexible portion would not be ruptured through sliding contact with the magnetic field sensor.

Claims

1. A key sheet for a pointing device in which a change in magnetic flux density, which occurs as a magnet laterally moves, is detected by at least one magnetic field sensor provided on a printed circuit board,

the key sheet comprising a base sheet made of a rubber-like elastic body, comprising:

a support portion for supporting a magnet;

a flexible portion that is laterally deformable to expand and contract so that the support portion can be laterally moved; and

a directional deformation portion formed in the flexible portion, for guiding and displacing a reverse face of the flexible portion away from a front face of a printed circuit board as the support portion laterally moves.

2. A key sheet for a pointing device according to claim 1, wherein the directional deformation portion is formed as a mountain fold flexure portion protruding away from the front face of the printed circuit board.

3. A key sheet for a pointing device according to claim 1, wherein at least the reverse face of the flexible portion is formed as a face inclined upward to a directional deformation portion side from a support portion side.

4. A key sheet for a pointing device according to claim 1, wherein the flexible portion is formed such that a thickness thereof increases from the directional deformation portion side to the support portion side.

5. A key sheet for a pointing device according to claim 1, wherein the magnet comprises one of an annular magnet and a plurality of magnet pieces that are disposed at annular positions, and wherein the magnet is magnetized radially inwards and outwards.

6. A key sheet for a pointing device according to claim 1, wherein the magnet comprises a plastic magnet.

7. A key sheet for a pointing device according to claim 1, wherein the support portion has a magnet accommodating recess portion, formed therein, and wherein the key sheet further comprises a key top for blocking the magnet accommodating recess portion, the key top being mounted to a front face of the support portion.

8. A key sheet for a pointing device according to claim 7, wherein the base sheet is formed of a translucent rubber-like elastic body, wherein the key top is formed of a translucent resin having a main body portion and a flange portion provided at a lower end of the main body portion, and wherein the magnet accommodating recess portion is formed at a position facing the flange portion in the support portion.

9. A key sheet for a pointing device according to claim 1, wherein the support portion is formed as a thin support portion having a penetration hole, wherein the key sheet further comprises an upper key top and a lower key top that sandwich a front face and a reverse face of the support portion by firm fixation through the penetration hole, and wherein the magnet accommodating recess portion is formed in the lower key top.

10. A pointing device, comprising:

a magnet;

a base sheet made of a rubber-like elastic body and having a flexible portion that is laterally deformable to expand and contract so that a support portion for supporting the magnet can be laterally moved; and

at least one magnetic field sensor that is provided on a printed circuit board and detects a change in magnetic flux density caused by the magnet moving laterally together with the support portion,

wherein the base sheet has a directional deformation portion formed in the flexible portion, which guides and displaces a reverse face of the flexible portion away from a front face of the printed circuit board as the support portion laterally moves.

11. A pointing device according to claim 10, wherein the magnetic field sensor is provided on the front face of the printed circuit board at a position facing the directional deformation portion.

12. A pointing device according to claim 10, further comprising an internal light source for light radiation provided on the front face of the printed circuit board at a position facing the directional deformation portion.

13. A pointing device according to claim 10, wherein the directional deformation portion is formed as a mountain fold flexure portion protruding away from the front face of the printed circuit board.

14. A pointing device according to claim 10, wherein at least the reverse face of the flexible portion is formed as a face inclined upward to a directional deformation portion side from a the support portion side.

15. A pointing device according to claim 10, wherein the flexible portion is formed such that a thickness thereof increases from the directional deformation portion side to the support portion side.

16. A pointing device according to claim 10, wherein the magnet comprises one of an annular magnet and a plurality of magnet pieces that are disposed at annular positions, and wherein the magnet is magnetized radially inwards and outwards.

17. A pointing device according to claim 10, wherein the magnet comprises a plastic magnet.

18. A pointing device according to claim 10, wherein the support portion has a magnet accommodating recess portion formed therein, and wherein the pointing device further comprises a key top for blocking the magnet accommodating recess portion, the key top being mounted to the front face of the support portion.

19. A pointing device according to claim 18, wherein the base sheet is formed of a translucent rubber-like elastic body, wherein the key top is formed of a translucent resin having a main body portion and a flange portion provided at a lower end of the main body portion, and wherein the magnet accommodating recess portion is formed at a position facing the flange portion in the support portion.

20. A pointing device according to claim 10, wherein the support portion is formed as a thin support portion having a penetration hole, wherein the pointing device further comprises an upper key top and a lower key top that sandwich a front face and a reverse face of the support portion by firm fixation through the penetration hole, and wherein the magnet accommodating recess portion is formed in the lower key top.