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:
Aug. 29, 1989
Filed:
Apr. 07, 1987
Yoshikazu Mihara, Yawata, JP;
Hiroshi Nakashima, Hirakata, JP;
Sanyo Electric Co., Ltd., Moriguchi, JP;
Abstract
In an electronic still camera system, a plurality of circular tracks are performed on a magnetic disc and the magnetic head 1 is used for both reproduction and erasing of the disc. When any one of the tracks is selectively erased, the reproducing operation is set by a control circuit 16 and tracking control of the magnetic head 1 is performed by a tracking servo circuit 5 of a Dither system. The DC component of a tracking control signal in an on-track state, that is, a signal DC' showing the average trace position of the magnetic head 1 on the disc is held in a sample and hold circuit 8. In addition, an oscillator 10 generates an AC signal AC' with an amplitude which moves the magnetic head 1 by the predetermined maximum amount d of track deviation. After a lapse of a predetermined period, tracking control of the magnetic head 1 is performed by a combined signal of the DC signal DC' and the AC signal AC' and reproduction operation is switched into erasing operation, so that the target track is erased.