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:
Sep. 07, 1993
Filed:
Aug. 07, 1991
Hiroaki Ono, Mito, JP;
Tomomi Okamoto, Katsuta, JP;
Seiji Ono, Yokohama, JP;
Shinji Ozaki, Funabashi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
This invention relates to a rotary drum device used in magnetic recording and playback apparatus such as VTRs, and particularly to the structure of a magnetic head and flying erasure head mounted on the rotary drum. The flying erasure head and recording head are of virtually same design, with the erasing frequency being set lower than the recording frequency with the intention of obliterating the old record instead of erasing it completely, and the flying erasure head has an azimuth angle of 0.degree. and operates for erasing the old record at a frequency close to the maximum recording frequency of the apparatus, allowing the erasure of record of any particular channel. The flying erasure head and recording head of the virtually same shape reduce their manufacturing cost. The erasing frequency lower than the recording frequency effects the head isolation, and the flying erasure head can be mounted without special shielding measures against such defective performance as crosstalk. The old record can be erased or obliterated easily, and the signal imprinted by the flying erasure head is not picked up because of the azimuth loss. The erasing signal frequency within the recording frequency band causes little crosstalk.