Image pick-up apparatus capable of stable flicker compensation without influence by reflectance of an object

摘要

In an image pick-up apparatus, the image on a visual field over an original copy is focused on an one-dimensional image pick-up device by a lens through a mirror. A prism for taking in the ambient light is disposed at the end portion of the one-dimensional image pick-up device. A sample-hold circuit samples and holds an ambient light signal portion of the image signal Vin and outputs a sample-hold signal Vref. A division circuit performs the operation of division Vin/Vref, using the sample-hold signal Vref. As a result, the image signal Vin will be normalized by the ambient light signal Vref for each scan line (line by line). An amplification circuit amplifies the output Vin/Vref of the division circuit so that the ambient light signal level may become VO and outputs it to an A/D conversion circuit. The image signal quantified by the A/D-conversion circuit is output to an external equipment by an external I/F circuit.