| 摘要 |
PURPOSE:To make it possible to effect the focusing operation irrespective of the kinds of an illuminating light source of a subject by photoelectrically converting the rays coming from two portions having different emanating irises of an object lens system and by interposing a relay lens and a space filter between the converting elements and an objective lens system. CONSTITUTION:An objective lens 2 is provided to face a subject 1 on an optical axis X so that the light enters a light receiving element PD through a space filter 3 and a relay lens 4. The elements PD1 and PD2 are arranged above and below the axis X so as to detect the phase difference, whereas the elements PD3 and PD4 remove the harmuful signals of a fluorescent lamp while being arranged at both sides of the axis X. The phases of the output waveforms of those elements are determined by the center of gravity of the emanating iris of the lens 2 so that the output signals of the respecitive elements take the waveforms which are formed by the multiplex operation of the signals having a focusing information and the output waveform signals of the light source illuminating a subject. Thus, if those signals are electrically processed at 7, it is possible to obtain signals indicating the degree of focusing and the direction and to indicated the degree of being out of focus at 8 so that the lens 2 can be moved along an optical axis X by a motor M. |
