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:
Dec. 09, 1986
Filed:
Apr. 17, 1985
James E Quackenbush, Chatsworth, CA (US);
Computer Memories, Inc., Chatsworth, CA (US);
Abstract
A head positioning system for a magnetic disk memory to position the head over a reference track so that track seeking operations can proceed from a known reference location. A plurality of control tracks are recorded adjacent the reference track with the first control track having a first type of control signal recorded thereon and the remainder having a second type of control signal. Means are provided to move the head a sub-multiple of the track spacing is to establish the head as close as possible to the centerline of the track, and to thereafter move the head integral multiples of the track spacing toward the reference track. The head is moved sequentially over the control tracks until the first type of control signal is detected. One more step then positions the head over the reference track. The sub-multiple movement capability is achieved through the use of a position encoder having a polyphase output, movement between zero crossings of the polyphase outputs being said submultiple. Selection of the optimal phase positions the head as close as possible to tracks centerline, and once chosen, the optimal phase is used in track seeking operations until a disturbing event or shut down and start up.