Photo electric feedback compensation controlled apparatus

Abstract

An apparatus for photo-electric automatic feedback compensation control is used with a charged coupled device (CCD) scanner to efficiently bring the CCD scanner into optimal operating range by controlling the output intensity of a light source based upon output readings from the CCD. A voltage controlled power supply drives a light source to emit light through an optical system to irradiate a CCD scanner. The voltage induced in the CCD scanner is output and manipulated to produce a digital control signal. When the photo-electric conversion rate of the CCD is too high, the light emitting intensity of the light source is reduced based upon the output of the CCD. When the photo-electric conversion rate of the CCD is too low, the output intensity of the light source is increased based upon the output signal of the CCD scanner. Thus, the signal-to-noise (S/N) ratio can be increased without necessity of manual adjustment, and the different problems generated by differences in apparatus characteristics or different environments and timing can be easily overcome.

Dependencies are inferred from the claim text.