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:
Oct. 01, 2002
Filed:
Apr. 21, 2000
Shoji Maruyama, Shizuoka-ken, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A servo-control apparatus for a motor includes a position detector for detecting a rotational position of a motor, a rotational speed signal generator for generating a rotational speed signal corresponding to a rotational speed of a motor, and a digital controller for generating an exciting electric current to be supplied to a coil of the motor as a pulse width modulated signal in accordance with the rotational speed signal from the rotational speed signal generator. A switching signal for switching the exciting electric current to be supplied to the coil of the motor is formed by a pre-driver in accordance with the position detection signal from the position detector, and the pre-driver combines the switching signal with the pulse width modulated signal from the digital controller to generate an electric current control signal by which the motor is driven, thereby coping with the speed change of the motor quickly and stably.