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. 28, 1988
Filed:
Oct. 15, 1984
Wataru Shimizu, Tokyo, JP;
Akira Yamashita, Tokyo, JP;
Kabushiki Kaisha SG, Tokyo, JP;
Abstract
The present device comprises a stator having a plurality of poles on which primary coils and at least one secondary coil is wound, and a rotor opposing the respective poles of the stator with gaps therebetween. A clock pulse generator is provided, and the respective primary coils are separately excited by reference AC signals which are out of phase with each other and are generated in response to a count of a counter counting a clock pulse signal from the clock pulse generator. The output of the secondary coil or coils provides an output signal resulting by phase shifting the reference AC signals in accordance with the rotational position of the rotor. The phase difference between the reference AC signal and the output signal is detected by obtaining a digital count representing the phase difference in synchronization with the counting by the counter to obtain detected digital phase difference data as an absolute rotational position data.