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:
Feb. 24, 1981
Filed:
May. 17, 1979
Hiromu Tabata, Kyoto, JP;
Onkyo Kabushiki Kaisha, Osaka, JP;
Abstract
A method and an apparatus for automatically establishing proper adjustment of recording bias current to obtain a flat reproduction frequency characteristic with a three-head type taperecorder in which sound recorded by a recorder head on a running magnetic tape may be immediately reproduced by a reproducer head immediately downstream of the recorder head. In the method and the apparatus, a composite calibration signal is generated by mixing a lower frequency signal and a higher frequency signal having the same level, the composite calibration signal is then recorded on a running tape while chronologically consecutively altering intensity of the recording bias current, immediately thereafter the recorded composite calibration signal is reproduced from the running tape and filtered off to obtain component lower and higher frequency signal outputs, subsequently the output sound levels of the filtered lower and higher frequency signals are compared, and finally the alteration of the recording bias current intensity is stopped when the output sound levels of the filtered lower and higher frequency signals have become substantially identical with each other.