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. 23, 1992
Filed:
Jun. 25, 1990
Shigeki Koizumi, Saitama, JP;
Yasuaki Imai, Saitama, JP;
Canon Denshi Kabushiki Kaisha, Chichibu, JP;
Abstract
A disk drive system in accordance with the present invention comprises a surface opposing type spindle motor which in turn comprises a spindle which is rotatably supported through a bearing by a chassis and to which is to be mounted a disk, a rotor yoke securely attached to the spindle, a driving magnet assembly, a printed-circuit board upon which are mounted a plurality of driving coils and a stator yoke disposed in opposing relationship with the driving magnet through the driving coils. A chassis has an opening in which is housed a head and the stator yoke is formed with a first recess in a region corresponding to a space in which the head is displaced. The bearing is a radial bearing having a diameter greater than that of the spindle. In order to avoid the interference between the driving coils and the first recess, the driving coils are disposed in an opening formed through the printed-circuit board or the space defined at the position corresponding to the recess. Furthermore, in order to balance the attractive forces of the driving magnet assembly or to cancel the cogging torque, the stator has a second recess at a position in opposing relationship with the first recess across the bearing.