Patent ID: 8605347

Claim:
An image reading apparatus which performs shading correction using black reference data, comprising: a light source configured to generate a red (R) color light, a green (G) color light and a blue (B) color light; an image sensor that transfers charge accumulated in a photoelectric conversion device to a shift register using shift pulses and outputs the charge transferred to the shift register as analog data; a reading control section that outputs a shift pulse which is a start timing of charge accumulation corresponding to each RGB color and controls a process of the light source generating a predetermined one of the R, G or B color light for a first predetermined period after a second predetermined period has elapsed since the output of the shift pulse; and a data processing section that does not obtain the data output from the image sensor as the black reference data according to the shift pulse and obtains the data output from the image sensor as the black reference data during a period that at least overlaps with the first predetermined period.