Touch keyboard

• US 3,971,013 A
• Filed: 04/23/1975
• Issued: 07/20/1976
• Est. Priority Date: 10/01/1974
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Challoner, Francis Loyola, Varadarajan, Hemmige Desikachar
• Primary Examiner(s): Habecker, Thomas B.
• Application Number:
  US05/570,990
• Time in Patent Office: 454 Days
• Field of Search: 340/365 C, 340/337, 340/173 PL, 313/201
• US Class Current: 345/174
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 17/98 having a plurality of control members, e.g. keyboard
• CPC Class Codes: H03K 2017/9613 using two electrodes per touch switch
• CPC Class Codes: H03K 2217/960745 Capacitive differential; e.g. comparison with reference capacitance

Abstract

A touch operated keyboard comprising an AC driven gas discharge panel display with conductive touch keys located to pick up an AC voltage from the stray field generated by the gas discharge panel is disclosed. A detector detects the drop in AC voltage level of a key due to the proximity of an operator'"'"'s finger. The touch keys may be deposited upon the surface of the gas panel or upon a separate transparent sheet. The keyboard may be operated to change the information displayed by the gas panel.

Claims

1. A touch operated keyboard comprising:

an AC driven gas discharge panel display;

at least one conductive touch key located proximate said display to pick up an AC voltage from said stray field generated by the gas discharge panel; and

means to detect the drop in AC voltage level of said at least one key due to the proximity of an operator'"'"'s finger.

2. A keyboard as claimed in claim 1, in which each touch key overlays a display position on the gas discharge panel and the touch key is operable to change the information displayed in that position and/or any other positions.

3. A keyboard as claimed in claim 1 in which said conductive key comprises a metallic layer deposited upon a surface of the gas discharge panel.

4. A keyboard as claimed in claim 3, in which each touch key overlays a display position on the gas discharge panel and the touch key is operable to change the information displayed in that position and/or any other positions.

5. A keyboard as claimed in claim 3, in which said metallic layer is transparent.

6. A keyboard as claimed in claim 5, in which each touch key overlays a display position on the gas discharge panel and the touch key is operable to change the information displayed in that position and/or any other positions.

7. A keyboard as claimed in claim 1 in which said conductive key comprises a metallic layer upon a sheet of transparent insulating material, and;

said transparent sheet is placed over the surface of said gas discharge panel.

8. A keyboard as claimed in claim 7, in which each touch key overlays a display position on the gas discharge panel and the touch key is operable to change the information displayed in that position and/or any other positions.

9. A keyboard as claimed in claim 7, in which said metallic layer is transparent.

10. A keyboard as claimed in claim 9, in which each touch key overlays a display position on the gas discharge panel and the touch key is operable to change the information displayed in that position and/or any other positions.