Apparatus for and method of driving motor to move object at a constant velocity

An image forming apparatus comprising:

• an image carrier;
• a motor to move the image carrier;
• a movement measuring unit that measures an amount of movement of the image carrier;
• a movement difference calculator that calculates a difference between the amount of movement and a target value;
• and
• a motor controller that controls the motor so that the image carrier moves at a constant velocity, based on the difference.

An image reading apparatus comprising:

• an object including an optical system for image reading;
• a motor to move the object along a plane of a target to be read;
• a movement measuring unit that measures an amount of movement of the object;
• a movement difference calculator that calculates a difference between the amount of movement and a target value;
• and
• a motor controller that controls the motor so that the object moves at a constant velocity, based on the difference.

A method of driving a motor to move an object, comprising:

• measuring an amount of movement of the object;
• calculating a difference between the amount of movement and a target value;
• and
• controlling the motor so that the object moves at a constant velocity, based on the difference.

A computer program product for driving a motor to move an object, the computer program product including computer executable instructions stored on a computer readable medium, wherein the instructions, when executed by the computer, cause the computer to perform:

• measuring an amount of movement of the object;
• calculating a difference between the amount of movement and a target value;
• and
• controlling the motor so that the object moves at a constant velocity, based on the difference.