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. 20, 1990
Filed:
Apr. 29, 1988
Donald Brunnett, Mission Hills, CA (US);
Ashok K Desai, Westlake Village, CA (US);
Mark A Heimbaugh, Canyon Country, CA (US);
Brand Technologies, Chatsworth, CA (US);
Abstract
The invention is directed to a head positioning servo system for disk drives employing a dedicated servo surface. A plurality of servo cells are recorded on the servo surface each including a sync field for storing multiple magnetic flux transitions. Each sync field consists of multiple unit areas wherein each of said transitions is selectively stored in one or more of said unit areas. In the preferred embodiment, each sync field includes double frequency (2f) transitions which are stored in a single unit area and single frequency (1f) transitions which are stored in two adjacent unit areas. The two types of transitions are used to encode each sync field to define either a valid ('1') sync or a nonvalid ('0') sync. Valid syncs are detected to generate sync pulses for timing control to derive both rotational and radial position information from the servo surface.