EP0322514A2
Expired / Lapsed
EP
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Keyboard switch system
Assignee: HP Inc
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Filing: 1988-09-15
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Granted: —
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Expires: 2008-09-15
Abstract
Abstract A keyboard (10) is described including a rigid base member (12) with a pattern of depressions (14) in it, electrical circuitry (16) on a flexible support carried by the base member, and a plurality of domes (24) covering the circuitry. The electrical circuitry defines a plurality of open switches (17) in registry with the pattern of depressions in the base. The pattern of domes is in registry with the open switches. The underside of each dome includes a conductive surface which will complete a connection across a switch when the dome is depressed, whereby the switch circuitry is deflected downwardly into a depression in the base member.
Inventors
- 👤 Brian G. Spreadbury
- 👤 Ralph W. Kinser, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 13:11
CPC Classifications
H; H01; H01H; H01H13/00; H01H13/70; H01H13/78; H01H13/80; H01H13/702; H01H2201/00; H01H2201/008
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
128 words
A keyboard (10) characterized by: (a) a rigid base member (12) including an upper surface and a plurality of depressions (14) in said surface in a predetermined pattern; (b) electrical circuitry (16) on a flexible support and carried by said base member, said circuitry defining a plurality of open switches (17) in registry with said pattern of depressions in said base member; (c) a plurality of flexible, resilient domes (24) covering said circuitry (16) and being in registry with said pattern of depressions, wherein the underside of each said dome (24) includes a conductive surface which is capable of completing an electrical connection at a said switch when said dome (24) is deflected downwardly against said circuitry, wherein said circuitry is deflected into said depression under said switch.
Claim 2
Dependent Claim
128 words
A keyboard (10) characterized by: (a) a rigid base member (12) including an upper surface and a plurality of depressions (14) in said surface in a predetermined pattern; (b) electrical circuitry (16) on a flexible support and carried by said base member, said circuitry defining a plurality of open switches (17) in registry with said pattern of depressions in said base member; (c) a plurality of flexible, resilient domes (24) covering said circuitry (16) and being in registry with said pattern of depressions, wherein the underside of each said dome (24) includes a conductive surface which is capable of completing an electrical connection at a said switch when said dome (24) is deflected downwardly against said circuitry, wherein said circuitry is deflected into said depression under said switch.
Claim 3
Dependent Claim
28 words
The keyboard in accordance with claim 1, characterized in that said base member (12) is metal and in that each said depression (14) includes a flat base surface.
Claim 4
Dependent Claim
25 words
The keyboard in accordance with claim 1 or 2, characterized in that said domes (24) are integral with a sheet (20) comprising a plastic film.
Claim 5
Dependent Claim
39 words
The keyboard in accordance with any of the preceding claims, characterized in that said conductive surface on the underside of each said dome (24) comprises an ink including conductive particles selected from the group consisting of silver and carbon.
Claim 6
Dependent Claim
28 words
The keyboard in accordance with any of the preceding claims, characterized in that said diameter of each said dome (24) and each said depression (14) are approximately equal.
Claim 7
Dependent Claim
22 words
The keyboard in acordance with any of the preceding claims, characterized in that each said switch comprises interdigitated, spaced conductive fingers (17,17A).
Claim 8
Dependent Claim
23 words
The keyboard in accordance with any of the preceding claims, characterized in that said flexible support for said electrical circuitry (16) comprises plastic.
Claim 9
Dependent Claim
41 words
The keyboard in accordance with any of claims 3 to 6, characterized by a dielectric spacer sheet (18) between said flexible support and said dome sheet (24), wherein said spacer sheet includes a plurality of openings in registration with said domes.
Claim 10
Dependent Claim
15 words
Use of the keyboard in accordance with any of the preceding claims for a calculator.
References Cited (Backward Citations)
No citation records indexed.
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