| 摘要 |
PURPOSE:To ensure the accurate automatic focusing even with a subject having meny horizontal lines for an image pickup device which performs focusing after detecting the high frequency component, by using an error signal between the high frequency component and the vertical correlation. CONSTITUTION:The output signal of a focus detecting image pickup element 108 is supplied to a high pass filter 110 which separates the high frequency component for an image pickup device which performs the focus control of an image pickup lens with a shift of the focus of an optical image formed at a secondary image pickup element. On the other hand, the output signal is delayed by a 1H delaying line 61 to obain a delayed signal. This delayed signal and a signal obtained before a delay undergo a subtraction, and this difference signal receives a wave detection. This difference signal is added with a signal obtained by giving a wave detection to the high frequency signal through an adder 64 to obtain an addition signal. Then a synchronous wave detection is carried out with the addition signal and a reference signal to obtain an error signal. As a result, it is possible to have an automatic focus control with higher precision. Furthermore the automatic focus control is possible even with a subject having many horizontal lines. |
