Position coordinate input device

• US 4,558,757 A
• Filed: 05/31/1984
• Issued: 12/17/1985
• Est. Priority Date: 06/06/1983
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Yamamoto, Osamu, Mori, Yoshihiro, Yamamoto, Kazumasa
• Primary Examiner(s): SCHREYER, STAFFORD
• Application Number:
  US06/615,534
• Time in Patent Office: 565 Days
• Field of Search: 178/18, 178/19, 178/20, 364/557, 364/556, 364/508, 364/571, 73/862.63, 73/862.65, 73/862.67, 177/211, 177/226, 338/3
• US Class Current: 178/18.05
• CPC Class Codes: G06F 3/04142 the force sensing means being located peripherally, e.g. disposed at the corners or at the side of a touch sensing plate
• CPC Class Codes: H01H 2239/052 Strain gauge

Abstract

A position coordinate input device including an input plate subjected, at a point, to an external force with a finger, etc. so as to input data of coordinates of the point into a computer and the like. The device further includes four elastic support members for supporting the input plate, a pair of two first detectors yielding outputs of temperature characteristics of a first sign and a pair of two second detectors yielding outputs of temperature characteristics of a second sign opposite to the first sign so as to enable accurate detection of the coordinates of the point of application of the external force in a simplified construction.

Claims

1. A position coordinate input device comprising:

an input plate;

four elastic support members for supporting said input plate;

four detector means for detecting that an external force has been applied to a point on said input plate, which are, respectively, provided on said elastic support members and are constituted by a pair of two first detector means yielding outputs having temperature characteristics of a first sign and a pair of two second detector means yielding outputs having temperature characteristics of a second sign opposite to the first sign; and

a circuitry for outputting, in response to said outputs from said four detector means, data of coordinates of said point, which data are corresponding to said outputs.

2. A position coordinate input device as claimed in claim 1, wherein said input plate is made of transparent material.

3. A position coordinate input device as claimed in claim 1, wherein said four elastic support members are, respectively, disposed at four corner portions of said input plate.

4. A position coordinate input device as claimed in claim 1, wherein each of said elastic support members has a shape of a flat plate and is formed, at one end thereof, with a first projection for supporting said input plate and is formed, at the other end thereof, with a second projection secured to a fixed member.

5. A position coordinate input device as claimed in claim 4, wherein each of said detector means is formed by a strain detector and is provided on a flat portion of each of said elastic support members, with said flat portion extending between said first projection and said second projection.

6. A position coordinate input device as claimed in claim 1, wherein each of said detector means is formed by a semiconducting strain gauge.

7. A position coordinate input device comprising:

an input plate;

four elastic support members for supporting said input plate, each of which has a shape of a flat plate and is formed, at one end thereof, with a first projection for supporting said input plate and is formed, at the other end thereof, with a second projection secured to a fixed member so as to be formed with a flat portion extending between said first projection and said second projection;

four detector means for detecting that an external force has been applied to a point on said input plate, two of which are each provided on an upper face of the flat portion of each of two of said four elastic support members and the remaining two of which are each provided on a lower face of the flat portion of each of the remaining two of said four elastic support members; and

a circuitry for outputting, in response to outputs from said four detector means, data of coordinates of said point, which data are corresponding to said outputs.

8. A position coordinate input device as claimed in claim 7, wherein said input plate is made of transparent material.

9. A position coordinate input device as claimed in claim 7, wherein said four elastic support members are, respectively, disposed at four corner portions of said input plate.

10. A position coordinate input device as claimed in claim 7, wherein each of said detector means is formed by a semiconducting strain gauge.

11. A position coordinate input device as claimed in claim 7, wherein each of said elastic support members is partially or wholly formed by an elastic plate made of stainless steel.

12. A position coordinate input device comprising:

an input plate made of transparent material;

four elastic support members for supporting four corner portions of said input plate, each of which has a shape of a flat plate and is formed, at one end thereof, with a first projection for supporting said input plate and is formed, at the other end thereof, with a second projection secured to a fixed member so as to be formed with a flat portion extending between said first projection and said second projection;

four strain detectors for detecting that an external force has been applied to a point on said input plate, each of which is formed by a semiconducting strain gauge;

two of said four strain detectors being each provided on an upper face of the flat portion of each of two of said four elastic support members, while the remaining two of said four strain detectors are each provided on a lower face of the flat portion of each of the remaining two of said four elastic support members; and

a circuitry for outputting, in response to outputs from said four strain detectors, data of coordinates of said point, which data are corresponding to said outputs.