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. 14, 1989
Filed:
Nov. 24, 1986
Takamichi Mitsuhashi, Saitama, JP;
Masao Tomioka, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A sound field expansion system applicable to a magnetic recording and reproducing apparatus (VTR) which can expand the sound field in a simple construction. In the sound field expansion system, a circuit for virtually forming two comb filter characteristics is provided by adding a first audio signal and a second audio signal delayed by a predetermined interval of time with respect to the first audio signal and adding the first audio signal which is passed through a phase shift circuit which shifts the phase of the first audio signal so that the reproduced sound field can remarkably be expanded. Furthermore, a correction circuit for providing a predetermined frequency characteristic for the first or second audio signal is installed so that an acoustic image having a desired frequency band can be positioned. The first and second audio signals may be monaural or stereophonic and are derived from demodulations of audio frequency-modulated (AFM) signal recorded on a common track of a magnetic tape together with a one-field video signal in a frequency division multiplex mode and time-axis-compressed pulse-code-modulated audio (PCM) signal recorded on the common track together with the one-field video signal in a time share mode.