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:
Jun. 25, 1991
Filed:
Jun. 20, 1989
Applicant:
Inventors:
Yoshihiro Yamamura, Tokyo, JP;
Hitoshi Fuda, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
379410 ; 379388 ;
Abstract
A voice conference system using echo cancelers. The system consists of at least two microphone to send out voice signals to a remote location, and a loudspeaker which receives in voice signals from the remote location. To prevent the microphone from picking up the loudspeaker sound, each microphone is hooked to the separate terminal of a comparator. Thus the a person's voice in one microphone will pass, but the loudspeaker sound being received equally by both microphones will be cancelled.