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:
Jun. 15, 2004
Filed:
Feb. 10, 1999
Mikio Tokuyama, Tsukuba, JP;
Hayato Shimizu, Ryugasaki, JP;
Satomitsu Imai, Odawara, JP;
Shozo Saegusa, Ibaraki-ken, JP;
Masahiko Sega, Hiratsuka, JP;
Toshihisa Okazaki, Odawara, JP;
Yuzo Yamaguchi, Shimonoseki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A magnetic disc unit which can restrain occurrence of flutter so as to countermeasure such a problem that the larger the rotational speed of discs, the higher the flutter, causing heat positioning errors, in order that the high rotational speed and high positioning accuracy are consistent with each other. Discs are surrounded along their outer peripheries by a shroud (outer wall) while a gap between end faces of the discs and the shroud is decreased to a predetermined distance, thereby to eliminate air pressure differential between opposite surfaces of each of the discs in order to reduce flutter.