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. 09, 1985
Filed:
Jul. 28, 1982
Teruo Iwasawa, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
A motor apparatus includes a motor, a first circuit for sensing a back electromotive force of the motor to provide a first signal, a second circuit for sensing a rotation speed of the motor to provide a second signal, a third circuit responsive to the first and second signals to provide a third signal corresponding to the first and second signals, and a fourth circuit for feeding to the motor a drive current with a magnitude corresponding to the third signal. The motor and the first to fourth circuits jointly form a negative feedback loop for setting up a proportional relationship of the second signal to the product of rotation speed and output torque of the motor. The second circuit changes the second signal proportionally to the rotation speed of the motor.