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. 13, 2013
Filed:
Dec. 29, 2010
Takashi Birumachi, Kashiwa, JP;
Takashi Birumachi, Kashiwa, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A drive apparatus for a stepping motor, including: a current detecting portion which detects a current value of phase current flowing through a phase winding; a constant-current-controlling portion which constant-current-controls the phase current flowing through the phase winding based on a detection result of the current detecting portion; a zero crossing detecting portion which detects a zero cross of the phase current based on the detection result of the current detecting portion; a phase difference detecting portion which detects a phase difference between the edge of a drive control pulse signal for the stepping motor and the zero cross detected by the zero crossing detecting portion; and a control device which causes the constant-current-controlling portion to perform constant-current control with a current value according to the phase difference detected by the phase difference detecting portion.