Camera focus detecting device

专利名称：Camera focus detecting device发明人：Harumi Aoki,Masahiro Kawasaki,Yoshio

Sawada

申请号：US06/117336申请日：19800131公开号：US04293207A公开日：19811006

摘要：An automatic focus detecting device for a camera in which a self- scanningphotoelectric element array is scanned at a rate depending upon the average amount oflight reflected from an object being photographed so that accurate focus detection ismaintained over a wide range of illumination conditions. An average illumination detectingelement is disposed at a position near or at a position optically equivalent to that of themicrophotoelectric elements of the element array. A low-pass filter couples the outputof the average illumination detecting element to a clock pulse generator which producesclock pulse signals of which the frequency varies according to the smoothed outputsignal from the low- pass filter representing the average illumination. As the brightnessof the object increases the frequency of the clock pulse signal correspondingly increasesto compensate for variations in brightness of the object.

申请人：ASAHI KOGAKU KOGYO KABUSHIKI KAISHA

代理机构：Sughrue, Mion, Zinn, Macpeak and Seas

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