Patent ID: 7129670
Filing Date: 2006-10-31
Classification: G01D,H02P

Abstract:
1. A drive device, comprising: a plurality of stepper motors, each of which has an excitation coil and a rotor rotating in accordance with variation in an excitation state of the excitation coil; a plurality of driven members, each of which moves in accordance with rotation of the rotor of the corresponding stepper motor; a plurality of stoppers, each of which stops the corresponding driven member mechanically at a zero position; and a controller, which controls the respective stepper motors so as to selectively perform either a normal operation in which a respective stepper motor is rotatably driven, or a zero-position detection operation in which the respective stepper motor is driven so that the driven member is moved to the stopper for detecting the zero position of the driven member, wherein the controller starts to perform the zero-position detection operation simultaneously in all of the stepper motors; and wherein the controller changes a stepper motor which has terminated the zero-position detection operation to the normal operation before at least one other stepper motor terminates the zero-position detection operation.