PURPOSE: To use an ordinary microswitch and to reduce the cost of the automatic ejection motor by a method wherein a microswitch which has been fitted into a recessed part formed in a housing is driven by an output cam shaft and the position of an output cam is detected.

CONSTITUTION: In a state that an output cam 61 is returned and moved, an actuator 71a for a microswitch 71 is made to protrude by a built-in spring, and it is inserted into a cutout in an output cam shaft 59. When an ejection switch is turned on and a motor 58 is turned, the shaft 59 is driven to turn via a gear train, the output cam 61 is turned, the actuator 71a for the switch 71 is pushed up, a power-supply input circuit is closed, and the motor 58 is turned continuously. When the cam 61 is turned and comes to a return movement position, the shaft 59 is set to a return movement position, the actuator 71a is inserted again into the cutout, and the position of the cam 61 is detected by the switch 71. When the microswitch is driven by the output cam shaft and the position of the output cam is detected in this manner, an ordinary microswitch can be used, and the cost of the motor can be reduced.