| 摘要 |
PURPOSE:To detect the movement of an object in the optical axis direction of a photographic lens by detecting the defocus quantity corresponding to the deviation quantity between an intended focal plane and the imaging plane of a light image. CONSTITUTION:A focus detecting means 104 which detects the focus adjusting state of the photographic lens 101 transmits the timing for the start and end of charge accumuation to a control means 109. The time from the end of the charge accumuation till the start of the next charge accumuation is spent for charge transfer and calculation of the defocus quantity. A time counting means 108 receives the timing for the start and end of the charge accumuation from the control means 109 and counts the time intervals thereof. The result thereof is stored into a memory 110 by the control means 109. The estimated defocus quantity taking the movement of subjects into consideration is held in a defocus quantity counting means 106. A driving signal generating means 105 generates the signals to run the driving motor of the lens 101 forward and backward and to stop the motor by responding to the content of the defocus quantity counting means 106. |
