| 摘要 |
PURPOSE:To obtain high focusing accuracy, by providing a depth-of-focus detecting means to an automatic focus controller applying the sampling of high frequency component and then varying the sampling period of the high frequency component. CONSTITUTION:The focal distance is varied by driving a zoom lens 1, and a focal distance detecting circuit 13 applies the voltage corresponding to the focal distance to a sampling pulse generating circuit 11. The circuit 11 varies the sampling period in response to the input voltage. On the other hand, an aperture value detecting circuit 12 applies the signal corresponding to the aperture value to the circuit 11 in case an iris 3 changes the depth of field in response to the brightness of a subject. Then the circuit 11 varies the sampling period in response to an input signal. In such a way, the accuracy of focus control is improved to prevent a malfunction. |
