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US 4,751,445 AGranted
Stepping motor control device
AssigneeCanon Kabushiki Kaisha
InventorShinji Sakai
Life of this patent
Estimating the term…
Abstract
A stepping motor control device is provided with a current control circuit by which the levels of currents of different driving power sources arranged to drive a stepping motor are virtually continuously changed, so that the motor can be controlled at intermediate phases thereof.
Claims24
An image sensing apparatus comprising:
- (a) a stepping motor including a plurality of electric-to-magnetic converting means for driving said stepping motor;
- (b) control means arranged to control the effective level of an electric input supplied to each of said electric-to-magnetic converting means in a stepwise manner including at least three steps;
- (c) exposure control means arranged to be driven by said stepping motor;
- and
- (d) light receiving means arranged to have the quantity of light incident thereon limited by said exposure control means.
2 more elements
An apparatus comprising:
- (a) displacement means;
- (b) electromagnetic means for causing a relative displacement of said displacement means;
- (d) control means arranged to variably control the effective level of said pulse signal in a stepwise manner including at least three steps;
- (e) image sensing means arranged to have the quantity of exposure light varied according to the displacement of said displacement means;
- and
- (f) selecting means for selecting the number of pictures to be taken by said sensing means.
3 more elements
An image pick-up device comprising:
- (a) means for limiting radiation from an object;
- (b) electromagnetic means for operating said limiting means;
- (c) means for selecting a number of a picture to be picked up by said image pick-up device;
- and
- (d) means for supplying a signal to said electromagnetic means, wherein an effective level of said signal is variable in accordnace with the number of said selecting means.
2 more elements
An apparatus comprising:
- (a) a stepping motor for moving a member;
- (b) means for detecting that said member reaches a prescribed position;
- (c) means for supplying a drive signal to said stepping motor;
- and
- (d) means for controlling said supplying means, which changes an effective level of the drive signal supplied from said supplying means by changing a duty of said drive signal in response to detection by said detecting means.
2 more elements
Dependencies are inferred from the claim text.