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:
Mar. 14, 1995
Filed:
Apr. 22, 1992
Applicant:
Inventors:
Assignee:
Kabushiki Kaisha Toshiba, Kanagawa, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
379390 ; 379388 ; 379402 ; 379410 ; 379406 ;
Abstract
A hands-free circuit includes a transmit noise level detector which detects a transmit noise level and a first comparator which compares the transmit noise level with a reference level. If the transmit noise level is higher than the reference level, the first comparator provides a control signal indicating a noisy state has been detected. In response to the control signal, a transmit audio level is attenuated. Further the attenuated transmit audio level is compared with a receive audio level by a second comparator which provides an output signal indicating either a transmit-mode or a receive-mode. In response to the output of the second comparator, one audio signal is attenuated.