| 摘要 |
PURPOSE:To prevent application of overload on a driving means and wasteful consumption of electric power by providing a terminal detecting means to detect whether the driving position of a lens for focusing a photographing lens arrives at the terminal of a driving range in a variable power region or not. CONSTITUTION:This device has a terminal detecting part 6 as the terminal detecting means consisting of a rotary encoder or the like which generates the pulses corresponding to the number of revolutions of a slit disk from a photointerruptor when said slit disk is rotationally driven. This detecting part detects the moving quantity of a focusing lens group 3 driven by a focus driving part and is so constituted as to output a stop signal by judging that the lens group 3 arrives at the terminal when there are no changes in the pulses within the prescribed time. The subsequent driving in the same direction is thereby prohibited when the driving position of the lens for focusing the photographing lens stops after arriving at the terminal of the driving range in the variable power region, by which the overloading of the driving means and the wasteful consumption of the electric power are suppressed. |
