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:
Aug. 24, 1993
Filed:
Aug. 13, 1990
Ichiro Hashimoto, Hitachi, JP;
Giichi Ishida, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A step motor which comprises a stator having a winding wound therearound, a rotor rotatably provided with respect to the stator, a multiplicity of pole teeth formed on mutually opposing faces of the stator and rotor, a position detector for detecting a position of the rotor, and switching means for changing over a phase current flowing through the winding wound around the stator on the basis of a position signal indicative of the position of the rotor, wherein the pole teeth and a position detectable portion are integrally formed on a rotary yoke of the rotor and the position detectable portion is detected by the position detector. A method for recording a position signal of the rotor in the step motor, wherein, when the position detectable portion is made in the form of a magnetic recording medium, the pole teeth are formed on a predetermined surface of a rotary yoke of the rotor, a magnetic recording medium is provided on a surface of the rotary yoke which is not provided with the pole teeth, and a position detecting signal is magnetically recorded on the magnetic recording medium with respect to a reference position of the pole teeth.