| 摘要 |
PURPOSE:To detect well the focusing state, by focusing lights, which are incident from an object through two different optical paths, onto two photodetector arrays and leading out their outputs as a time series signal and weighting this signal at a time series timing and integrating the output. CONSTITUTION:The first and the second lenses 4 and 5 are the same lens and are moved similarly, and the first and the second photodetector arrays 6 and 7 are placed in equivalent relations to an object S. Illuminance distribution signals obtained from the first and the second photodetector arrays 6 and 7 are inputted to a signal processing circuit 11 having the weighting function, the integrating function, the dividing function, the comparing function, the polarity discriminating function, etc. and are subjected to operation processings, and a signal indicating focus, front focus, or rear focus is inputted to an output controlling circuit 12. In case of front focus, a plus signal is outputted and a motor 13 is rotated normally to get the in-focus state; and in case of rear focus, a minus signal is outputted and the motor 13 is rotated reverse to get the in-focus state. |
