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:
Nov. 21, 1978
Filed:
Feb. 23, 1978
Abstract
An echo canceller in a telephone circuit for minimizing a residual echo obtained by subtracting a pseudo-echo reproduced from an impulse response of an echo path from a true echo, in which the inpulse response is corrected by the use of the product of the residual echo and received input. A variable coefficient circuit is provided between a multiplier for obtaining the product and a circuit for correcting the impulse response. A control circuit is provided for reducing the coefficient of the variable coefficient circuit in accordance with the lapse of time of the duration of the received input exceeding a predetermined threshold level after receiving a circuit connection completion signal of the telephone circuit.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile