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:
Mar. 17, 1987
Filed:
Feb. 12, 1985
Teac Corporation, Tokyo, JP;
Abstract
A magnetic disk drive is disclosed which has a write circuit for alternately exciting the a pair of coils of a read/write head in response to a two level write data signal when a write gate signal is in a prescribed state, thereby causing the coils to create magnetic fluxes in the opposite directions in the core. The write circuit excites a different one of the coils of the read/write head each time the write data signal changes in level from a predetermined one to the other. A final excitation circuit is provided for delaying, for example, the write gate signal for a preassigned length of time in order to cause the write circuit to excite a preselected one of the coils of the read/write head in a prescribed direction upon completion of the writing of the write data signal. Consequently, the residual magnetism of the read/write head is of one and the same orientation upon completion of writing, making possible the accurate detection of the peaks of the reproduced waveform at the time of subsequent reading.