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:
Apr. 02, 1991
Filed:
May. 18, 1988
Mitsuhiro Otokawa, Yokohama, JP;
Hiroyuki Takimoto, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
There is disclosed a brushless motor provided with a speed detector for detecting the rotating speed of rotor; a synthesizer for synthesizing the output wave forms of inverse electromotive force of different phases of the brushless motor; a detector for detecting the synthesized wave form from the synthesizer; an inverter for inverting the detected wave form from the detector; an oscillator for generating a predetermined frequency; a frequency divider for dividing the frequency from the oscillator according to the output from the inverter; a counter for counting the clock output signal from the frequency divider, latching the count in a cycle of a signal from the speed detector and resetting the count; and a drive controller for generating a control voltage in response to the output from the counter thereby controlling the current supplied to the rotor.