| 摘要 |
PURPOSE:To prevent the increase of a step motor driving current and to miniaturize a camera by providing a circuit means which extends, the pulse width of a step motor driving pulse when an energizing means of a lens driving member is charged. CONSTITUTION:A mobile member 1 is driven by a step motor 3 and is moved between a focusing area and an exposure adjusting area. After the end of exposure, the motor 3 continues to turn in the reverse direction furthermore for the purpose of returning the member 1 to the initial position. When the member 1 is brought into contact with the contacting part 5c of a lens driving member 5, a charging stage detecting circuit 24 outputs a signal to a step motor driving pulse generating circuit 25. The circuit 25 reduces the frequency of a quick driving inverted pulse and extends the pulse width to output a pulse corresponding to a heavy load. then, the motor 3 reduces the rotation frequency and increases the output torque to torn the member 1, to which the load of a tension spring 11 is applied, counterclockwise furthermore. Thus, the increase of the driving current of the motor 3 is prevented to charge the spring 11, and th camera is miniaturized.
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