AUTOMATIC FOCUSING DEVICE

摘要

PROBLEM TO BE SOLVED: To enable all the image sensors to output a correct video signal and to calculate an exact focusing distance by providing a means for sensing subject luminance viewed by a line sensor in every line sensor and controlling integral time for every line sensor based on output from the means. SOLUTION: A CCD image sensor transfers a light quantity signal by the accumulated charge of every element to a shift register in parallel by impressing a shift pulse on an integration control gate when photocurrent integration is performed for a proper time altogether to the respective elements; then it successively reads out the charge signal in the shift register as a voltage signal by impressing a transfer clock on the shift register. PD arrays I to IV are the array of the elements of the CCD image sensor, and photodiodes for monitoring PDM1 and PDM2 are arranged along the PD arrays I and II in order to fix the integral time of photocurrent according to the average luminance of the image projected on the PD array.