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:
Jan. 24, 1984
Filed:
Dec. 11, 1981
Akihiko Naito, Tokyo, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A fail-safe CATV system center facility in which abnormalities in a normal down-data signal transmitter are automatically corrected for so that there is no loss of reception at the terminal units. FM and AM detectors detect the presence or absence of the normal FSK data signal. The outputs of the FM and AM detectors are AND'ed together then delayed to control the switch state of a switch which selects between the outputs of the normal down data signal transmitter and a back-up transmitter for coupling through to the cable system. The back-up transmitter produces a clock signal which is obtained by modulating a carrier signal having the same frequency as that of the normal down data signal, preferably a frequency shift keyed signal.