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:
Oct. 15, 1991
Filed:
Apr. 05, 1989
Naoto Matono, Yawata, JP;
Sanyo Electric Co., Ltd., Moriguchi, JP;
Abstract
A working amount detecting marker formed by laminating first and second marker layers each having a predetermined shape when seen from above. Two sides contouring the respective marker layers intersect each other at a point located at a specified position where working is to be completed. When the portion of a magnetic head to be opposed to magnetic recording media is formed by grinding or grooving, the sectional configuration appears on the ground surface, indicating whether the amount of grinding or grooving is insufficient or excessive. The point of intersection, when appearing on the ground surface, readily indicates completion of grinding or grooving with high accuracy.