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. 17, 1989
Filed:
Aug. 08, 1988
Masahiro Ohsawa, Kanagawa, JP;
Eiichi Yonezawa, Kanagawa, JP;
Fuji Electric Co., Ltd., Kanagawa, JP;
Abstract
A spindle motor for rotating magneto-optical discs that are attracted and held on a fixed position at an end of a motor driven shaft by means of a clamping rotor with internal field magnets. The spindle motor has a set of stator coils and a set of field magnets held internally mounted on the shaft side of the clamping rotor. The field magnet and stator coil sets are arranged at a regular interval in a ring around the circumference of the clamping rotor and of a shield member of the spindle motor respectively, leaving a thin gap between the stator coils and the field magnets. The saucer-like clamping rotor is made of a non-magnetic material and applied at the disc side, on which side a magneto-optical disc is charged, of the rotary shaft. The field magnets, being fitted on the face of the clamping rotor opposed to the magneto-optical disc mounted face, function both as a means for driving the clamping rotor for motor operation, and as a disc-attracting device.