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:
Jun. 30, 1998
Filed:
Mar. 14, 1997
John C Tsai, Saratoga, CA (US);
Excel Precision, Inc., Santa Clara, CA (US);
Abstract
A servotrack writing apparatus (10) having a reference section (30), a workpiece section (32), and a tracking section (34). With the reference section (30) a standard is established without a disk drive workpiece (12) mounted. A workpiece (12) is then mounted in the workpiece section (32) with a beamsplitter-reflector unit (52) attached to the actuator arm (20) bearing the read-write head (18) which is to be used for servotrack writing, and verification information is obtained for comparison with the standard. Based upon this comparison, correction of workpiece (12) mounting offset and eccentricity of beamsplitter-reflector unit (52) mounting may then be performed before servotracks are written, or compensation for such offset and eccentricity may be performed while servotracks are written. The tracking section (34) operates using closed-loop feedback to slave the actuator arm (20) of the workpiece (12) to a tracking arm (62) and then may use a laser interferometer (70) to precisely measure location of a tracking retro-reflector (68) mounted on the tracking arm (62), thereby permitting very accurate and controlled positioning of the synchronized read-write head (18) while servotrack writing is carried out.