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:
Nov. 06, 2007
Filed:
Apr. 23, 2005
David Treves, Palo Alto, CA (US);
Thomas A. O'dell, Campbell, CA (US);
David Treves, Palo Alto, CA (US);
Thomas A. O'Dell, Campbell, CA (US);
Komag, Inc., San Jose, CA (US);
Abstract
An optical test head comprises a laser source for providing a laser beam. The laser beam passes through a cylindrical lens for modifying the shape of the beam and a spherical lens for concentrating the beam onto a workpiece (typically a magnetic disk platter). The cylindrical lens both a) elongates the laser beam along the radial direction of the platter (by reducing the effective numerical aperture in the radial direction); and b) causes the beam to be out of focus in the radial direction (although the beam is typically in focus in the circumferential direction). The size of the beam in the radial direction is substantially insensitive to the position of the cylindrical lens.