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:
Oct. 07, 1986
Filed:
Apr. 18, 1985
Eiichi Ishii, Tokyo, JP;
Makoto Yoshimizu, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
The magnetic tape recording apparatus includes an erasing head for demagnetizing a magnetic tape, a recording head for recording an input recording tape on the magnetic tape, an oscillator generating an erasing A.C. signal the amplitude of which is changed in accordance with the kind of the magnetic tape, an amplitude limitter receiving the erasing A.C. signal to produce a constant A.C. signal irrespective of the kind of the magnetic tape, a gain-controlled amplifier amplifying the constant A.C. signal with a gain controlled with a gain control signal to obtain a A.C. bias signal, an adder adding the A.C. bias signal with the input recording signal to apply the added signal to the recording head, and a means for obtaining said gain control signal from the added signal. The gain control signal obtaining means may include a low-pass filter receiving the added signal, a peak-detector converting the output from the low-pass filter to a D.C. signal, and a comparator comparing the D.C. signal with a reference voltage to obtain the gain control signal.