Lens control apparatus and lens control method
AssigneeOlympus Corporation
InventorYohei Komiyama
Life of this patent
Estimating the term…
Abstract
A lens control apparatus for moving a lens in an optical axis direction, including: a stepping motor for driving the lens; a controller for obtaining a drive amount on the basis of an input target position, instructing a rotational position of the stepping motor to perform drive control, wherein the controller obtains, in accordance with a first drive amount when the stepping motor is driven to a current position, a second drive amount from the current position to a target position, a third drive amount obtained by correcting the second drive amount, and instructs a rotational position on the basis of the third drive amount.
Claims8
A lens control apparatus for moving a lens in an optical axis direction, comprising:
- a stepping motor for driving the lens;
- a memory for storing a deviation amount between a rotational position generated when the stepping motor is driven for the same rotational position with different drive amounts, and an actually-stopped rotational position, and a determination value for determining whether or not the deviation amount depends on the drive amount;
- and
- a processing circuit for obtaining a drive amount on the basis of an input target position, instructing a rotational position of the stepping motor to perform drive control,
- wherein the processing circuit (1) obtains, responsive to a determination that both a first drive amount when the stepping motor is driven to a current position, and a second drive amount from the current position to the target position, are smaller than the determination value, a correction value for the correction based on the deviation amount,
- (2) obtains a third drive amount using the second drive amount and the correction value, and
- (3) instructs a rotational position on the basis of the third drive amount.
A lens control method of a lens driving apparatus having a stepping motor for moving a lens in an optical axis direction, for obtaining a drive amount on the basis of an input target position, and instructing a rotational position of the stepping motor to drive, the method comprising:
- reading a first drive amount when the stepping motor is driven to a current position;
- obtaining a correction value for the correction from a deviation amount between the rotational position generated when the stepping motor is driven for the same rotational position with different drive amounts, and an actually stopped rotational position;
- obtaining, responsive to a determination that both the first drive amount and a second drive amount from the current position to the target position, are smaller than a determination value for determining whether or not the deviation amount depends on the drive amount, a correction value based on the deviation amount;
- obtaining a third drive amount by correcting the second drive amount using the correction value;
- and
- instructing a rotational position on the basis of the third drive amount.
A lens control method for use with a lens driving apparatus having a stepping motor for moving a lens in directions along an optical axis of the lens, the method comprising:
- obtaining a first drive amount value corresponding to a number of pulse drives needed to have the stepping motor move the lens to a target position on the optical axis;
- reading a previously stored second drive amount value corresponding to a previous actual drive amount;
- responsive to a determination that both the first drive amount value and the second drive amount value are smaller than a drive amount threshold for defining whether or not a deviation amount corresponding to a difference between an instructed stop position of the stepping motor and a detected stop position of the stepping motor, depends on the drive amount,
- (1) determining the deviation amount based on at least one of the first drive amount value and the second drive amount value, and
- (2) determining a correction value based on the deviation amount, and
- otherwise, responsive to a determination that neither of the first drive amount value and the second drive amount value is smaller than the drive amount threshold,
- (1) determining a correction value based on a fixed deviation amount;
- obtaining a third drive amount value by correcting one of the first drive amount value and the second drive amount value using the correction value;
- and
- controlling the stepping motor using the third drive amount value.
Dependencies are inferred from the claim text.