Lens controlling apparatus
AssigneeCanon Kabushiki Kaisha
InventorsHitoshi Yasuda, Masahide Hirasawa
Life of this patent
Estimating the term…
Abstract
A lens controlling apparatus includes a lens-driving stepping motor, a driving current forming circuit for forming a driving current waveform to be supplied to the stepping motor, an inputting circuit for inputting a stop instruction to stop the lens-driving stepping motor, a stopping circuit for performing the operation of stopping the stepping motor in accordance with the stop instruction, a phase detecting circuit for detecting the phase of the driving current waveform to be supplied to the stepping motor, and an inhibiting circuit for inhibiting the stop instruction from being executed except when the phase of the driving current waveform detected by the phase detecting circuit is a predetermined phase.
Claims19
A lens controlling apparatus comprising:
- (a) a lens system having a lens group and an iris;
- (b) an actuator for moving the lens group;
- (c) a stepping motor for driving said lens group;
- (d) detecting means for detecting a state of the iris;
- and
- (e) control means for controlling said stepping motor by a micro-steps driving operation and controlling to decide a stopping phase of said stepping motor on the basis of the state of said iris detected by said detecting means.
A lens controlling apparatus comprising:
- (a) a lens group;
- (b) an actuator for moving said lens group;
- (c) a stepping motor for driving said actuator;
- (d) detecting means for detecting a depth of field;
- and
- (e) control means for controlling said stepping motor by a micro-steps driving operation and controlling to decide a stopping phase of said stepping motor on the basis of the depth of field detected by said detecting means.
A device for controlling a lens, comprising:
- a focusing lens;
- a diaphragm;
- a stepping motor for driving the focusing lens;
- a motor driving circuit for controlling the drive of the stepping motor;
- an iris encoder for detecting an aperture value of the diaphragm;
- and
- a control circuit which controls the motor driving circuit to drive the stepping motor by a micro-steps driving operation and to control the stopping position of the focusing lens and controls the motor driving circuit to change a stopping phase of the stepping motor on the basis of an output of the iris encoder.
A lens controlling apparatus comprising:
- (a) a lens system having a lens group and an iris;
- (b) a motor for moving the lens group;
- (c) driving means for driving said motor;
- (d) detecting means for detecting a state of the iris;
- and
- (e) control means for controlling said driving means by a micro-steps driving operation and controlling a stop operation of said driving means on the basis of information provided by said detecting means so as to delay executing of stopping said driving means until a rotating phase of said motor becomes a predetermined phase in the case that a stopping command is received.
Dependencies are inferred from the claim text.