PURPOSE: To attain complete correction by using a sensitivity component to apply division processing to a signal component subtracting a dark signal from a picture signal in a picture reader.
CONSTITUTION: Before a signal is read, a dark signal output and the sensitivity component are stored in each volatile memory. In reading the picture signal, a picture signal output inputted to an A/D converter 1 is a value adding a real picture signal component to the dark signal component. After this value is digitized, the result is inputted to a subtracted side of a subtraction circuit 21. The dark signal is read from the volatile memory in synchronizing with the read of the picture signal and inputted to a subtractor side of the subtraction circuit 21. An output of the subtraction circuit 21 is inputted to a dividend side of a division circuit, the sensitive component of the sensor is read from the volatile memory in synchronizing with the output of the result of subtraction and inputted to a divisor side of the division circuit. Then the output of the division circuit depends only on the density level of an original.
UMAJI TOORU
IZAWA YUUJI
TSUKADA TOSHIHISA
