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. 15, 1994
Filed:
Feb. 20, 1992
Takao Nakamura, Yokohama, JP;
Nobuya Sekiyama, Yokohama, JP;
Tsuneo Kawai, Yokohama, JP;
Yoshiki Kato, Nishitama, JP;
Hitachi Ltd., Chiyoda, JP;
Abstract
A thin plate such as a magnetic disk substrate is rotatably placed in a hole of a carrier provided between upper and lower surface plates forming a dynamic pressure producing surface in a temperature-controlled polishing liquid. When the number of revolutions of the surface plates increases, the dynamic pressure effect of the polishing agent is produced between the surface-plate surface and the substrate surface so that the substrate is polished in the non-contact state with the surface plate. The substrate surface is polished by fine free abrasive grains in the polishing liquid flowing between the surface plate and the substrate to provide a high plane degree to which surface precision of the surface plate is transferred. The present invention makes employs a float polishing, and is particularly suit to surface polishing of a thin plate such as a magnetic disk substrate which resets a residual processed strain. A magnetic disk having an excellent surface state can be realized.