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:
Jan. 16, 1979
Filed:
Nov. 02, 1976
James O Jacques, Tracy, CA (US);
Martin O Halfhill, San Jose, CA (US);
Xerox Corporation, Stamford, CT (US);
Abstract
A servo system including a recording head to sense servo data on a disk track for fine positoning of the head and an external transducer for generating signals representing the coarse position of the head. A micro-processor stores the coarse positon signals which include information as to repeatable error such as wobble of the disk. A compensator maintains information concerning small offsets of the disk due to, for example, temperature variations. During coarse positioning of the head, from one track to a desired track, the stored repeatable error information and stored offset information is used to generate error signals to control movement of a carriage connected to the head, whereby the head follows the repeatable error and offset to arrive coarsely on the desired track. After coarse positioning is complete, fine positioning information from the recording head, which information includes the offset information, and the stored repeatable error information are used to generate error signals to control movement of the carriage for fine positioning purposes.