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:
Jul. 20, 1999
Filed:
Jun. 17, 1996
Victor Company of Japan, Ltd., Yokohama, JP;
Abstract
A bi-directional optical wireless communication apparatus comprises a modulator outputting a narrow band signal whose center frequency is selected from N center frequencies, an optical transmitter transmitting an optical signal from the narrow band signal, an optical receiver for receiving N optical signals, N receiving circuits corresponding to the N center frequencies, a cancelling circuit for cancelling the optical signal received by the optical receiver via reflective object in received N optical signals using the narrow band signal in accordance with a magnitude of the optical signal received by the optical receiver, a frequency discriminator discriminating frequencies of the received N optical signals, and a control circuit. The frequency discriminator discriminates for an interval that the optical transmitter does not transmit the optical signal. Then, the modulating circuit continuously outputs a received signal from one of N receiving circuits corresponding to the discriminated frequency and the modulator modulates the narrow band signal to have a center frequency other than the discriminated frequency under control of the control circuit. The interval is repeated with a repetition randomly set interval.