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:
Oct. 12, 1976
Filed:
May. 19, 1975
Harold James Beecroft, Minneapolis, MN (US);
Thomas Francis Burniece, III, Edina, MN (US);
Douglas Joseph Hennenfent, Minneapolis, MN (US);
Control Data Corporation, Minneapolis, MN (US);
Abstract
Apparatus for increasing the density of data tracks on the recording surfaces of a disc memory of the type having at least one pre-recorded servo track which is continuously read by a servo head whose output signal changes with its position relative the track and is constantly adjusted to maintain a predetermined servo head output signal condition, without increasing the number of servo tracks in the memory. The improvement comprises a servo head having a plurality of flux paths, each passing through a signal winding, and having adjacent read gaps arranged and spaced such that by successively employing one or another of the read gaps to sense a servo track, the number of data tracks can be increased by an integer multiple. Signal winding selection apparatus is added which receives the track address from the external user, and which, dependent thereon, selects one of the signal windings and supplies its servo signal to the controller which shifts the servo arm and maintains the selected servo gap in the desired position adjacent the desired servo track.