| 摘要 |
PURPOSE:To attain the sure and optimum focus adjustment by controlling a contrast signal such that a low or a high contrast signal takes a maximum value over the entire focal point when a prescribed luminance and contrast difference are deficient in an object. CONSTITUTION:A video signal from an image pickup section 2 is a low frequency signal via a low pass filter 11 at first and only the low frequency component is a signal having a level corresponding to the strength of contrast, that is a low contrast signal by a low frequency differentiation device 12 secondly. Moreover, only the high frequency component is a high contrast signal by a high frequency differentiation device 22 in the 3rd. The peak value is obtained from the low contrast signal and the high contrast signal is obtained by peak hold circuits 13, 23, and the peak value and the low frequency component are inputted in a microcomputer 19. The microcomputer 19, based on the input signal, controls the circuit by driving an actuator to apply optimum focus adjustment over the entire focal position. |
