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:
Mar. 27, 2001
Filed:
Dec. 16, 1997
Gerd Reime, Schömberg, DE;
Nokia GmbH, Bochum, DE;
Abstract
The invention relates to an apparatus for wireless optical transmission of video and/or audio information, such as television broadcasts or video recordings, with IR radiation radiated into the surrounding free space by an optical transmitter and received by one or more photo receivers. It is the object of the invention to provide means for extending the transmission range of wireless optical transmission systems and for simplifying signal processing, so that television broadcasts or video recordings can be reliably transmitted under ambient light conditions typical in residential buildings while requiring only limited additional circuitry for matching the optical transmission channel and a small number of luminescent diodes. This object is solved in that at least for the upper frequency spectrum of the video and/or audio information, the optical transmission is based on a pulse-shaped source signal, with the information represented by the temporal position of the signal edges between pulses and non-pulse periods. A simple edge detector converts the source signal into a channel pulse signal which includes a short spike-shaped channel pulse synchronous with each signal edge in the source signal. The optical receiver includes a 1:2 frequency divider for restoring from the received channel pulse signal the original shape of the pulse-shaped source signal.