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:
Apr. 03, 1979
Filed:
Sep. 07, 1977
Masakatsu Watanabe, Akatsukashin, JP;
Hochiki Corporation, Tokyo, JP;
Abstract
An alarm system utilizes a bidirectional wired TV system constructed to transmit a TV signal received by a community antenna to a central station and a plurality of subscribers' stations through a bidirectionally transmissible line. Each of the subscribers' stations is provided with an automatic and/or manual alarm signal generator for generating a low frequency alarm signal representing any of emergency conditions and the subscriber's number, a carrier wave generator, and a modulator for modulating a high frequency carrier wave signal generated by the carrier wave generator with the alarm signal from the alarm signal generator. The central station is provided with a demodulator for receiving and demodulating the modulated alarm signal transmitted from any subscriber's station through the bidirectionally transmissible line, an alarm signal identifying device energized by the demodulated alarm signal from the demodulator, a carrier wave generator, and a remodulator for remodulating a different high frequency carrier wave signal generated by the carrier wave generator with the demodulated alarm signal from the demodulator. Any of the subscribers' stations are each further provided with a redemodulator for receiving and redemodulating the remodulated alarm signal transmitted from the central station through the bidirectionally transmissible line, and an alarm signal identifying device energized by the redemodulated alarm signal from the redemodulator.