Contact sensitive substrate

• US 5,403,648 A
• Filed: 04/28/1993
• Issued: 04/04/1995
• Est. Priority Date: 04/30/1992
• Status: Expired due to Term

• Current Assignee: Varintelligent (BVI) Limited
• Original Assignee: Varintelligent (BVI) Limited
• Inventors: Lee, Goon N., Chan, Yiu S., Poon, Ying M., Liao, York
• Primary Examiner(s): Ryan, Patrick J.
• Assistant Examiner(s): LAM, CATHY FONG FONG
• Application Number:
  US08/054,784
• Time in Patent Office: 706 Days
• Field of Search: 428/209, 428/901
• US Class Current: 428/209
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2017/9615 using three electrodes per touch switch
• CPC Class Codes: Y10S 428/901 Printed circuit
• CPC Class Codes: Y10T 428/24917 including metal layer

Abstract

A contact sensitive substrate for electronic equipment comprising a plurality of touch pads and respective associated leads defining an array of touch positions on a front (in use) face of the substrate.

Claims

1. A contact sensitive substrate for electronic equipment, comprising:

(i) a plurality of touch pads;

(ii) a plurality of leads for said touch pads;

(iii) said touch pads and leads defining an array of touch positions, each said touch position including a plurality of touch pads, the touch pads of each said touch position being electrically isolated from one another;

(iv) said substrate having a major surface; and

(v) said array being at said major surface, wherein respective leads of said touch pads run from opposite sides of said major surface, and contact between two or more touch pads established through contact by a user permits transmission of a signal.

2. A substrate as defined in claim 1, wherein there are two touch pads at each of said array of touch positions.

3. A substrate as defined in claim 2, wherein there is a ground touch pad between said two touch pads at each said touch position.

4. A substrate as defined in claim 1, wherein said array is linear.

5. A substrate as defined in claim 4, wherein said array is a two-dimensional matrix of a plurality of said linear arrays.

6. A substrate defined in claim 2, wherein there is a ground pad between said two touch pads at each said touch position and wherein there is a lead to said ground pad shared between each said touch position.

7. A substrate as defined in claim 1, wherein said substrate is a sheet of glass on which each touch position is fixed.

8. A substrate as defined in claim 7, wherein each touch position is fixed by etching.

9. A substrate as defined in claim 8, wherein the sheet of glass is coated with indium tin oxide.

10. A substrate as defined in claim 7, wherein the glass is transparent.

11. An electronic display, in combination with a substrate as defined in claim 1.