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. 28, 1995
Filed:
Jul. 19, 1993
Hirofumi Nishimoto, Kanagawa, JP;
Kensaku Abe, Saitama, JP;
Eiji Sato, Tokyo, JP;
Nobuo Kobayashi, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
A headphone apparatus includes a speaker unit accommodated in an accommodating member of an open-air type, a microphone disposed at a front side of the speaker unit, a circuit arrangement mounted on a circuit board in the speaker unit including a filter for lowering a level of a high frequency component of a signal picked up by the microphone, and a negative feedback loop for feeding back an output of the filter to the speaker unit to thereby lower the level of a low frequency component of circumference noise output from the speaker unit. This headphone apparatus further includes an equalizer having a frequency characteristic substantially opposite to that of the filter, wherein an input audio signal is added to the negative feedback loop through the equalizer and then output from the speaker unit.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile