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. 18, 1987
Filed:
Oct. 31, 1985
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
An automatic graphic equalizer for a sound system has circuitry for measuring the effect of the physical environment receiving a sound on the frequency characteristics of the sound, and for adjusting the characteristics of a graphic equalizer to compensate for distortions in the desired flat frequency response caused by the physical environment. The circuitry includes a pink noise generator supplying pink noise to the graphic equalizer during an initialization operation, the graphic equalizer being controlled by a controller to present a flat frequency characteristic. The equalizer output is sent to a speaker which supplies the pink noise as a sound signal to the selected environment. A microphone picks up the sound in the selected environment and converts it to an electrical signal which is supplied through an ALC amplifier to a frequency-variable band-pass filter to detect the signal level in each of the equalizer frequency bands. The level signals are smoothed in a level detector and digitized to be input to the controller which readjusts the graphic equalizer to compensate for distortions in the desired flat frequency response caused by the selected environment.