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:
Mar. 07, 2000
Filed:
Mar. 11, 1999
Katsuhiko Yamaguchi, Sagamihara, JP;
Naoyuki Goto, Sagamihara, JP;
Kabushiki Kaisha Ohara, , JP;
Abstract
A glass-ceramic substrate for a magnetic head has as its predominant crystal phase a mixed crystal of lithium disilicate (Li.sub.2 O.2SiO.sub.2) and either or both of .alpha.-quartz (.alpha.-SiO.sub.2) and .alpha.-cristobalite (.alpha.-SiO.sub.2), the .alpha.-quartz has a globular grain structure each globular crystral grain being made of aggregated particles and having a grain diameter within a range from 0.1 .mu.m to 3.0 .mu.m, the .alpha.-cristobalite has a globular grain structure each globular grain having a grain diamter within a range from 0.1 .mu.m to 1.0 .mu.m, and surface roughness (Ra) of the glass-ceramic substrate after polishing is within a range from 5 .ANG. to 50 .ANG..