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:
Oct. 05, 1982
Filed:
Dec. 13, 1979
Paul C Davis, Reading, PA (US);
Raymond G Jackson, Indianapolis, IN (US);
Joseph J Nahas, Wyomissing, PA (US);
Dale H Nelson, Cumberland, IN (US);
DeWitt G Ong, Tempe, AZ (US);
Brian A Wittman, Indianapolis, IN (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
In a multifrequency generator providing tone signaling for a telephone, the common switching functions are performed by solid state switching circuitry (1200). Improved signal transfer between the telephone line and transmit and receive transducer of the telephone is provided by arranging the solid-state transmit and receive switches (1201, 1401) in a gain configuration to increase the level of the speech signal. The tone signals are digitally synthesized and use an integrated R-C oscillator (600) as a reference. Button down and button up debouncing of a contact closure signal from a single contact per button keypad is provided.