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. 05, 1977
Filed:
Mar. 19, 1975
Chansak Laoteppitaks, Orange, CT (US);
Lincoln Henthorn, Cheshire, CT (US);
Charles B Falconer, Hamden, CT (US);
Chestel, Inc., Chester, CT (US);
Abstract
A decoder is disclosed for use in a communication system wherein bits of information are conveyed by the transmission, on a communication line, of code tones of distinctive frequencies each corresponding to a respective bit of information. The decoder divides an incoming signal into repetitive intervals having durations dependent on the period of the signal and provides digital measurements of the length of the interval by counting clock pulses during each interval. The digital measurements are then processed to test for persistence of the signal at a stable frequency for a predetermined time and for matching of said stabilized frequency to a recognized code tone frequency. More specifically, such decoder is disclosed as part of a larger decoder for use in, for example, a telephone communication system wherein dial numbers or other characters are communicated by way of simultaneously transmitted code tone pairs.