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Publication numberWO2004025402 A3
Publication typeApplication
Application numberPCT/US2003/028179
Publication date25 Nov 2004
Filing date10 Sep 2003
Priority date10 Sep 2002
Also published asWO2004025402A2
Publication numberPCT/2003/28179, PCT/US/2003/028179, PCT/US/2003/28179, PCT/US/3/028179, PCT/US/3/28179, PCT/US2003/028179, PCT/US2003/28179, PCT/US2003028179, PCT/US200328179, PCT/US3/028179, PCT/US3/28179, PCT/US3028179, PCT/US328179, WO 2004/025402 A3, WO 2004025402 A3, WO 2004025402A3, WO-A3-2004025402, WO2004/025402A3, WO2004025402 A3, WO2004025402A3
InventorsRoy J Lahr
ApplicantRast Associates Llc, Roy J Lahr
Export CitationBiBTeX, EndNote, RefMan
External Links: Patentscope, Espacenet
Rf absorption switching for keyboard signaling
WO 2004025402 A3
Abstract
A keyboard device (10) includes a plurality of keybutton (140), a resonant tank circuit (120) corresponding to each of the plurality of keybuttons (140), each resonant tank circuit (120) configured to absorb energy at a respective predetermined frequency, a sensor device (80) configured to sense absorption of energy by the resonant tank circuit at the predetermined frequencies, an emitter device (70) configured to emit energy in a path of the resonant tank circuits toward the sensor device, and a determination device configured to determine a depression state of the keybuttons in accordance with absorption, sensed by the sensor device, at the predetermined frequencies of the energy emitted by the emitter device.
Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3818472 *26 May 197218 Jun 1974K MaukR.f. system for detecting unauthorized travel of articles through a selected zone
US5378069 *15 Dec 19933 Jan 1995Product Engineering & Mfg., Inc.Environmentally safe touch typing keyboard
US5677688 *13 May 199214 Oct 1997David Sarnoff Research Center, Inc.Optomechanical information entry device
Classifications
International ClassificationH03K17/94
Cooperative ClassificationH03K17/94
European ClassificationH03K17/94
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