The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 28, 2004
Filed:
Nov. 16, 2001
Tiina Hämäläinen, Trc, FI;
Henri Vähä-Ypyä, Tampere, FI;
Risto Pirhonen, Tampere, FI;
Vesa Peili, Tampere, FI;
Nokia Corporation, Espoo, FI;
Abstract
The present invention relates to proximity sensors. It also relates to proximity sensors in electronic devices using lightguides. More specifically the invention relates to a simple self monitoring of optical proximity sensors. This can be achieved according to one embodiment of the present invention by a system of lightguides for the use in proximity sensor. The lightguide system comprises a transceiver lightguide to direct-transmitter to a predefined direction, and a receiver lightguide to direct transmitter light reflected from an object towards a receiver, where the transceiver and receiver lightguides comprise diffracting surfaces to direct a part of-the light from the transmitter as a self monitoring beam in a direction towards a receiver.