Patent ID: 8792148

Claim:
An inspection method for an image reading apparatus in which image information on a surface of an original illuminated by a light source is imaged on multiple light receiving element lines arranged in a main scanning direction through an imaging optical system, and the image information of colors different from each other are read by the respective multiple light receiving element lines, the inspection method for the image reading apparatus comprising: acquiring a first color misregistration amount from image information based on a first striped pattern located at a position optically equivalent to a position of the surface of the original with respect to the multiple light receiving element lines, the first striped pattern having white lines and black lines of a same width alternately aligned, and having longitudinal directions of the white lines and the black lines aligned in a sub-scanning direction; acquiring a second color misregistration amount from image information based on a second striped pattern located at a position optically equivalent to the position of the surface of the original with respect to the multiple light receiving element lines, the second striped pattern having white lines and black lines of a same width alternately aligned, and having longitudinal directions of the white lines and the black lines inclined with respect to the main scanning direction; and calculating a color misregistration amount in the sub-scanning direction based on the first color misregistration amount and the second color misregistration amount.