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:
Aug. 31, 1999
Filed:
Nov. 22, 1996
Applicant:
Inventors:
Trevor Dragwidge, Hampshire, GB;
Richard George, Copenhagen, DK;
Adrian Kennard, Berkshire, GB;
Richard Williams, Surrey, GB;
Assignee:
Nokia Mobile Phones Limited, Salo, FI;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
379391 ; 379390 ; 379388 ;
Abstract
A telephone, particularly a portable handset operable in a digital radio telephone system, has a sidetone gain circuit 28 which applies one of two levels of gain G1 G2 dependent on whether a detector 30 detects a high magnitude of input signal 14 corresponding to speech or a low level of input signal 14 corresponding to an idle condition. With varying magnitude of input signal 14, the gain switches between G1 and G2 dependent on two thresholds T1 and T2 of the input signal, the relationship including hysteresis to prevent unduly rapid switching.