Citizen Watch Company, Ltd.

Yasuhisa Hirosawa

Fumio Nakajima

Akira Nikaido

Takayasu Machida

A carriage device used for moving and positioning a magnetic head opposite prescribed tracks of a magnetic disk has the magnetic head mounted on a carriage which has linear motor mechanisms built integrally therein. The linear motor mechanisms incorporate coils secured to part of the carriage and permanent magnets secured aorund the coils. Guide rails serving to support the carriage within the range of the sliding motion of the coils are made of a magnetic substance.

Carriage device for moving and positioning magnetic head

The present invention provides a micro stepping motor for more accurately stepping and positioning a magnetic head in a magnetic disc system. The stepping motor has a permanent magnet type rotor and a stator encircling the rotor, the rotor having a plurality of pole teeth formed therein with a fine pitch and the stator also having a plurality of pole teeth formed therein with a fine pitch and disposed opposed to the pole teeth in the rotor, the stator pole teeth being divided into at least one pair of pole tooth groups which are out of phase relative to each other by an electrical angle of 180 degrees. A single common stator coil is provided to the pair of stator pole tooth groups. Thus, the stepping pitch of the rotor is determined by the pitch in the pole tooth groups, whereby the rotor can steppingly be driven with higher density even by the reduced number of stator coils. In addition, plural pairs of pole tooth groups can be formed such that at least two pairs of pole tooth groups and the corresponding two stator coils will be provided to determine the stepping angle of the rotor optionally under the multi-excitation.

Growing community of inventors

Saitama, Japan

Yasuhisa Hirosawa