EP 0001882 A1 19790516 - Depressible contactless key for generating electric signals in an electronic keyboard.
Title (en)
Depressible contactless key for generating electric signals in an electronic keyboard.
Title (de)
Kontaktfreier Drücktaster zur Verwendung in einer elektronischen Tastatur.
Title (fr)
Touche à pression sans contact utilisable dans un clavier électronique.
Publication
Application
Priority
IT 6948677 A 19771107
Abstract (en)
An elastomeric material conductive under pressure is suitable for use in a keyboard. When not compressed the material is insulating. When a key (21) is depressed, the pressure renders the material (11) conductive and completes a circuit (14, 11, 16, 17, 15). In order to prolong the life of the material when it is repeatedly compressed, a magnetic field is used during polymerization of an elastomer in which magnetic powder is dispersed. The material becomes piezoconductive in a preferred direction parallel to the applied field.
IPC 1-7
IPC 8 full level
H01C 10/10 (2006.01); H01H 13/702 (2006.01); H01H 13/785 (2006.01)
CPC (source: EP)
H01C 10/106 (2013.01); H01H 13/702 (2013.01); H01H 13/785 (2013.01); H01H 2201/036 (2013.01); H01H 2207/008 (2013.01); H01H 2227/012 (2013.01); H01H 2227/014 (2013.01)
Citation (search report)
- [XP] DE 2729959 A1 19780105 - JAPAN SYNTHETIC RUBBER CO LTD
- CH 547007 A 19740315 - WIFO FORSCHUNGSINST AG
- DE 1939642 B2 19750109
- DE 2006176 B2 19730419
- [A] FR 2182099 A1 19731207 - BATTELLE MEMORIAL INSTITUTE [CH]
- [D] JOURNAL OF APPLIED PHYSICS, vol. 44, no. 6, June 1973, B.E. SPRINGETT: "Conductivity of a system of metallic particles dispersed in an insulating medium", pages 2925 to 2926
- [D] SEVENTH ANNUAL CONNECTOR SYMPOSIUM PROCEEDINGS, October 1974, Camden, New Jersey, (USA) CH. KUIST: "Anisotropic Conduction in Elastomeric Composites, pages 203 to 209
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 0001882 A1 19790516; EP 0001882 B1 19811209; DE 2861435 D1 19820204; IT 1091947 B 19850706
DOCDB simple family (application)
EP 78300393 A 19780918; DE 2861435 T 19780918; IT 6948677 A 19771107