Drive control apparatus and drive control method
AssigneeCanon Kabushiki Kaisha
InventorJunki Yoshimuta
Life of this patent
Estimating the term…
Abstract
A drive control apparatus includes a stepping motor, a position detection unit configured to detect a rotational position of a rotor of the stepping motor, a feedback drive unit configured to drive the stepping motor by a feedback control based on an output from the position detection unit, an open loop drive unit configured to drive the stepping motor by an open loop control, and a switching unit configured to switch the driving of the stepping motor between the driving of the stepping motor by the feedback control and the driving of the stepping motor by the open loop control, wherein the feedback drive unit and the open loop drive unit are both configured to drive the stepping motor by microstep driving.
Claims9
A drive control apparatus comprising:
- a position detection unit configured to detect a rotational position of a rotor of a stepping motor;
- a feedback drive unit configured to drive the stepping motor by a feedback control based on an output from the position detection unit;
- an open loop drive unit configured to drive the stepping motor by an open loop control;
- and
- a switching unit configured to switch the driving of the stepping motor between the driving of the stepping motor by the feedback control and the driving of the stepping motor by the open loop control,
- wherein the switching unit is capable of switching the driving of the stepping motor between the driving of the stepping motor by the feedback control and the driving of the stepping motor by the open loop control,
- wherein the feedback drive unit and the open loop drive unit are both configured to drive the stepping motor by microstep driving,
- wherein the open loop drive unit controls the driving of the stepping motor such that as a driving frequency of the rotor increases, a microstep division ratio of the microstep driving decreases, and
- wherein the feedback drive unit sets the division ratio of the microstep independently of the open loop drive unit.
An image pickup apparatus comprising:
- a stepping motor configured to drive an optical element;
- a position detection unit configured to detect a rotational position of a rotor of the stepping motor;
- a feedback drive unit configured to drive the stepping motor by a feedback control based on an output from the position detection unit;
- an open loop drive unit configured to drive the stepping motor by an open loop control;
- and
- a switching unit configured to switch the driving of the stepping motor between the driving of the stepping motor by the feedback control and the driving of the stepping motor by the open loop control,
- wherein the switching unit is capable of switching between the driving of the stepping motor by the open loop control and the driving of the stepping motor by the feedback control,
- wherein the feedback drive unit and the open loop drive unit are both configured to drive the stepping motor by microstep driving,
- wherein the open loop drive unit controls the driving of the stepping motor such that as a driving frequency of the rotor increases, a microstep division ratio in the microstep driving decreases, and
- wherein the feedback drive unit sets the division ratio of the microstep independently of the open loop drive unit.
A method of controlling driving of a stepping motor by selecting either one of an open loop control and a feedback control,
- wherein the driving of the stepping motor is controlled by microstep driving in both the open loop control and the feedback control,
- wherein in the open loop control, the driving of the stepping motor is controlled such that the microstep division ratio in the microstep driving decreases as the driving frequency of the rotor of the stepping motor increases,
- and wherein in the feedback control the microstep division ratio is set independently of the open loop control.
Dependencies are inferred from the claim text.