| 摘要 |
PURPOSE:To decrease the consumption of a battery by a titled device, by detecting a stop of a lens by change of a speed signal of lens movement and stopping an electric supply to a motor. CONSTITUTION:A defocus amount DELTAL outputted from a range finding part 9 and a signal in the direction of lens extension are inputted to a controller 11, and here a lens extension amount DELTAd is calculated and digitized to be outputted to an up-and down-counter 12. A signal for driving a motor 2 is outputted to a driving circuit 13 from the controller 11, and a pulse of each unit distance of lens movement is inputted to the up-and down-counter 12 from a generator 10, and the lens extension amount DELTAd which is reset at each inputted pulse is subtracted, and when the value of the counter 12 becomes zero, the lens is focused and a signal of stopping the motor 2 is put out to a driving circuit from the controller 11. When a detecting circuit 34 is under electric supply of motor and the lens is stopped mechanically, the stop of lens is detected by change of outputted pulses of the pulse generator 10 and a signal for stopping the motor is outputted to the controller 11. |
