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. 17, 1996
Filed:
Apr. 11, 1995
Peter M Baumgart, San Jose, CA (US);
Christopher S Gudeman, Los Gatos, CA (US);
Douglas J Krajnovich, San Jose, CA (US);
Steven W Meeks, San Jose, CA (US);
Thao A Nguyen, San Jose, CA (US);
Fior D Sargent, San Jose, CA (US);
Andrew C Tam, Saratoga, CA (US);
Gerard H Vurens, Fremont, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Controlled laser texturing of a magnetic recording disk is accomplished by use of a textured test band on the disk and an analyzing laser system to provide feedback to the texturing laser. The analyzing laser system determines, from diffracted laser light, the average height of the laser-induced bumps formed in the test band by the texturing laser. The analyzing laser beam is directed to the substrate surface and overlaps a group of individual bumps formed in a repetitive pattern. A scanning linear photodector array receives light diffracted from the surface. The digitized output of the array is the angular distribution of diffracted light intensities and is used to compute the average height of the bumps in the test band. The disk is then translated radially so that the texturing laser is aligned with the region of the disk where the textured landing zone is to be placed. Then, in response to the computed value of average bump height in the test band, a correction signal or signals is output to modify one or more parameters of the texturing laser so that the texturing laser can form bumps of the correct average height in the textured landing zone.