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. 09, 1992
Filed:
May. 19, 1989
Yoichi Ito, Ibaraki, JP;
Fumihiko Yamanushi, Tokyo, JP;
Atsushi Yoshioka, Kanagawa, JP;
Susumu Ohtsuka, Ibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A reproducing circuit for use in a magnetic recording and reproducing apparatus having a recording circuit operable to record a video luminance signal in either a conventional recording mode or in a High-Band mode has a first automatic gain control circuit for holding a level of a reproduced FM signal at an input thereof constant, a recording mode determination circuit having an input connected to the first automatic gain control circuit and responsive to an output of the first automatic gain control circuit for determining which the first or second recording mode is used to record the FM signal under reproduction, a first equalizer circuit for equalizing the reproduced FM signal suitably for the first recording mode, a second equalizer circuit for equalizing the reproduced FM signal suitably for the second recording mode, a switch circuit for selecting an output of either the first equalizer circuit or the second equalizer circuit according to an output of the recording mode determination circuit, a second automatic gain control circuit for holding an output level of the switch circuit, whereby the recording mode of the signal undergoing reproduction is automatically determined and the characteristics of the reproducing circuit is changed automatically suitably.