| 摘要 |
PURPOSE:To sufficiently remove noise by separating and extracting a modulation component which is the carrier of an autofocus information by a band-pass filter circuit. CONSTITUTION:Noise is removed by separating and extracting only the modulation component of an autofocus information by passing a photoelectric signal from two divided photosensors 10a and 10b through shape band-pass filter circuits 17 and 28, said signal being produced from the beam of infrared rays reflected from an object to be photographed and being modulated by a constant frequency. Further, since a control is performed such that the quantity of light emitted from a light emitting diode 6 is reduced when the quantity of light reflected from the object is large and increased when the last-said quantity is small, only a necessary and minimum quantity of emitting light is required.
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