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. 14, 2004
Filed:
Nov. 10, 1999
Toshihiko Nakata, Hiratsuka, JP;
Hideaki Sasazawa, Yokohama, JP;
Kenji Furusawa, Hiratsuka, JP;
Minako Morisato, Yokohama, JP;
Hideo Yamakura, Yokohama, JP;
Toshio Tamura, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A method of measuring variation in dimensions and alignment error of thin film magnetic heads formed on a raw bar cut-off from a substrate is provided. Such method comprises illuminating a MR element and a resistance detector element which is formed for monitoring a lapping process, both of which are formed on the raw bar, with illuminating light whose wavelength is 300 nm or less; forming an image by imaging light reflected from the elements; and converting the image to an image signal through photoelectric conversion so as to detect variation in dimensions of the MR element and the resistance detector element formed on the raw bar, and alignment error between the MR element and the resistance detector element with a high degree of accuracy.