| 摘要 |
PURPOSE:To execute easily false resolution and focus detection which is strong against a noise, by suppressing a distinction variation signal of an object image whose phase is different, by synchronizing detecting. CONSTITUTION:Photoelectric transducing units 2, 3 photodetect an image forming beam of an object image which passes through a photographic lens 1, scan it mechanically or electrically, and photoelectrically convert a spatial distinction distribution of the object image to distinction information of time series, which is an electric signal. A signal which has added 10 these converted signals through differential amplifiers 8, 9, and each output signal of the differential amplifiers 8, 9 are multiplied 11, 12, respectively, and after that, the sum total is derived by integrators 13, 14 respectively. Accordingly, a random noise superposed on a distinction signal of each object image on the units 2, 3 is reduced to half, also at a different non-focused position like false resolution, a signal which is 180 deg. out of phase is offset, and in an operation and display unit 15, whether the present focal face is before or behind the expected focal face is decided and displayed. |
