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.

Date of Patent:
Nov. 17, 2015

Filed:

Aug. 29, 2013
Applicant:

Seiko Instruments Inc., Chiba, JP;

Inventors:

Saburo Manaka, Chiba, JP;

Kenji Ogasawara, Chiba, JP;

Kazumi Sakumoto, Chiba, JP;

Keishi Honmura, Chiba, JP;

Kosuke Yamamoto, Chiba, JP;

Satoshi Sakai, Chiba, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G04C 3/14 (2006.01); H02P 8/38 (2006.01); H02P 8/02 (2006.01); H02P 8/16 (2006.01); H02P 8/34 (2006.01);
U.S. Cl.
CPC ...
H02P 8/38 (2013.01); G04C 3/143 (2013.01); H02P 8/02 (2013.01); H02P 8/16 (2013.01); H02P 8/34 (2013.01);
Abstract

A rotation detection circuit detects an induced current flowing through a drive coil of a stepping motor in a detection section divided into a plurality of sections, and detects a rotation state of the stepping motor on the basis of a pattern indicating whether or not the induced current exceeds a predetermined reference value in each of the sections. A control unit selects a drive pulse corresponding to the rotation state detected by the rotation detection unit, and supplies a drive current to a drive coil to rotatably drive the stepping motor. The rotation detection unit carries out detection by selecting a detection direction of the induced current in the sections after the first section on the basis of whether or not the induced current exceeding each of a plurality of reference values is detected plural times in the first section.


Find Patent Forward Citations

Loading…