Motor driving apparatus and optical apparatus
AssigneeCanon Kabushiki Kaisha
InventorHiroshi Akada
Life of this patent
Estimating the term…
Abstract
The motor driving apparatus includes a motor driving a driven member, and a controller performing, from a start of driving of the motor, acceleration drive of the motor on the basis of a predetermined acceleration pattern with open-loop control, and then perform, in response to increase of a driving speed of the motor or the driven member to a predetermined speed, drive of the motor with feedback control. The controller changes the predetermined acceleration pattern and the predetermined speed depending on a magnitude of a load acting on the motor or the driven member.
Claims13
A driving apparatus comprising:
- a motor configured to drive a driven member, the motor including:
- a rotor having a cylindrical magnet whose outer circumferential surface is magnetized;
- a first yoke having a first magnetic pole portion which faces the outer circumferential surface of the cylindrical magnet;
- a second yoke having a second magnetic pole portion which faces the outer circumferential surface of the cylindrical magnet;
- a first coil configured to magnetize the first magnetic pole portion;
- a second coil configured to magnetize the second magnetic pole portion;
- a position detector configured to detect rotation position of the rotor;
- an open-loop driver configured to switch an energization state of the first coil and second coil at a predetermined time interval;
- a feedback driver configured to switch an energization state of the first coil and the second coil according to an output of the position detector;
- and
- a controller configured to switch the open-loop driver and the feedback driver at a predetermined driving speed,
- wherein the controller changes the predetermined driving speed according to the magnitude of the load acting on the motor.
An optical apparatus comprising:
- a motor configured to drive a lens, the motor including:
- a rotor having a cylindrical magnet whose outer circumferential surface is magnetized;
- a first yoke having a first magnetic pole portion which faces the outer circumferential surface of the cylindrical magnet;
- a second yoke having a second magnetic pole portion which faces the outer circumferential surface of the cylindrical magnet;
- a first coil configured to magnetize the first magnetic pole portion;
- a second coil configured to magnetize the second magnetic pole portion;
- a position detector configured to detect rotation position of the rotor;
- an open-loop driver configured to switch an energization state of the first coil and second coil at a predetermined time interval;
- a feedback driver configured to switch an energization state of the first coil and the second coil according to an output of the position detector;
- and
- a controller configured to switch the open-loop driver and the feedback driver at a predetermined driving speed,
- wherein the controller changes the predetermined driving speed according to the magnitude of the load acting on the motor.
Dependencies are inferred from the claim text.