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:
Dec. 15, 1992
Filed:
Aug. 31, 1990
Michael E Locke, Santa Clara, CA (US);
ROLM Systems, Santa Clara, CA (US);
Abstract
Apparatus for detecting and identifying DTMF signals in connection with a voice store and forward equipment (VSF) and for preventing talk-off, whether generated by the VSF or by a user of the VSF. In particular, the apparatus for use in connection with an interface which receives an analog signal from and applies an analog signal to a telephone line, the apparatus including: (a) detection means, responsive to an analog signal received from the interface, for detecting DTMF signals in the received analog signal and for generating DTMF indication signals in response thereto; (b) means for storing a representation of the received analog signal and at least some of the DTMF indication signals and for applying at least some of the DTMF indication signals to a decision means; and (c) means for retrieving a representation of an output analog signal and a representation of output DTMF indication signals and for applying them to the decision means; wherein the decision means is means for applying the output analog signal to the interface.