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.

Date of Patent:
Nov. 05, 2002

Filed:

Aug. 05, 1999
Applicant:
Inventors:

Minoru Yoshida, Saitama-ken, JP;

Fumio Matsushita, Saitama-ken, JP;

Satoshi Kumada, Tokyo, JP;

Yoshiki Ohta, Saitama-ken, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04B 1/00 ; H03G 3/00 ;
U.S. Cl.
CPC ...
H04B 1/00 ; H03G 3/00 ;
Abstract

A rear speaker and a front speaker are provided in a room. A microphone is disposed at a listening position between the front and rear speakers for picking up a first sound from the front speakers and a second sound from the rear speaker. Time lags of the first sound and the second sound is obtained from the outputs of the microphone, and the time difference between the time lags is obtained. An antiphase audio signal opposite to a reflected composite signal included in the first sound picked up by the microphone is provided by the sound field correcting circuit. The antiphase audio signal with the same amplitude is delayed based on the time difference and emitted from the rear speaker so as to cancel the reflected composite signal.


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