Force sensor, force detection system and force detection program

• US 20050252303A1
• Filed: 12/23/2004
• Published: 11/17/2005
• Est. Priority Date: 05/14/2004
• Status: Active Grant

• Current Assignee: Appside Co., Ltd.
• Original Assignee: Appside Co., Ltd.
• Inventors: Taniguchi, Nobumitsu
• Granted Patent: US 7,395,721 B2
• Time in Patent Office: Days
• US Class Current: 73/780
• CPC Class Codes: G01L 1/142 using capacitors
• CPC Class Codes: G01L 5/165 using variations in capacitance
• 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
• CPC Class Codes: H01H 2025/004 the operating member being depressable perpendicular to the other directions
• CPC Class Codes: H01H 2239/006 Containing a capacitive switch or usable as such
• CPC Class Codes: H01H 25/041 having a generally flat operating member depressible at different locations to operate different controls
• CPC Class Codes: H03K 17/9625 using a force resistance transducer

Abstract

The present invention is intended to provide a force sensor that converts a force into capacitance and makes it possible to generate a plurality of outputs with different output characteristics, force detection system, and a force detection program for it.

The force sensor 20 has a displacement unit 24 for generating a displacement when a force is applied; a single or a plurality of first sensor units (36, 36A, 36B, 36C, and 36D) for generating a first output C₁ from said displacement of the displacement unit; and a second sensor unit 44, which is annexed to the first sensor unit, for generating a second output C₂ from the displacement of said displacement unit. The force detection system enhances the output accuracy by means of the first and second outputs of such a force sensor. The force detection program is used in the force detection system for executing the output process.

Claims

1. A force sensor comprising:

a displacement unit that displaces when a force is applied;

a single or a plurality of first sensor units that generates a first output from the displacement of said displacement unit; and

a second sensor unit that is annexed to said first sensor unit and generates a second output from the displacement of said displacement unit.

2. A force sensor of claim 1, wherein the displacement of said displacement unit includes either a deformation of said displacement unit or a movement of said displacement unit by force or both thereof.

3. A force sensor of claim 1, wherein the output of said second sensor unit rises steeply from the output of said first sensor unit and shifts to a saturated state ahead of the output of said first sensor unit.

4. A force sensor of claim 1, wherein said second sensor is provided in the center of said displacement unit, while said first sensor unit is provided to surround said second sensor.

5. A force detection system comprising:

a force sensor equipped with first and second sensor units in a displacement unit that displaces when a force is applied and generates first and second outputs that represent the displacement of said displace unit; and

a processing unit that obtains said first output using said second output of said force sensor as the reference information for said first output.

6. A force detection system of claim 5, wherein said processing unit extracts time information representing level periods that exceed a specified level from said second output and obtains said first output referencing said time information.

7. A force detection system of claim 5 wherein said second sensor unit of said force sensor shifts said second output to a saturated condition soon after said displacement unit starts to displace.

8. A force detection system of claim 5 wherein said reference information is zero point information of said first output.

9. A force detection program comprising:

a function of obtaining a first output from a first sensor unit provided in a displacement unit that displaces when a force is applied;

a function of obtaining a second output from a second sensor unit provided in said displacement unit;

a function of extracting time information representing a level period that exceeds a specified level from said second output; and

a function of obtaining said first output referencing said time information.