PURPOSE: To supply a uniform illumination to the object to be read, by correcting the illumination distribution of the illumination light source by the illumination distribution which is obtained from the object to be read.
CONSTITUTION: In case when the object to be read 45 is read by the TV camera 41, the read result (c) is A/D-converted by the illumination distribution (a) on the surface of the object 45, and the sensitivity distribution (b) of the TV camera 41, moreover it is converted to a reciprocal, and it is stored in the correction function memory 48 as a correction function. The driver 49 modulates brightness by the place of the planar illumination light source by use of the correction function of the correction function memory 48, so that the information on the surface of the object 45 can be read with uniform intensity of illumination, as the illumination distribution (d) which has been corrected.
FUJIWARA KATSUMI
HIZUKA TETSUO
