Image reading apparatus, storage medium storing abnormality determination program, and abnormality determination method

A non-transitory computer-readable storage medium storing an abnormality determination program to be run on an image reading apparatus, the image reading apparatus including a medium transportation path along which a medium is transported, a read unit that reads the medium and is provided on the medium transportation path, and a control unit that processes read data read by the read unit and controls transportation of the medium along the medium transportation path, the abnormality determination program comprising:

• first determination processing of setting an abnormality determination area for a leading-edge area of the medium and performing abnormality determination for the abnormality determination area;
• wherein
• the first determination processing includes
• acquiring, at an upstream position in a medium transportation direction of the abnormality determination area, a distance WL from a center position in a medium width direction intersecting with the medium transportation direction to one edge in the medium width direction and a distance WR from the center position to the other edge in the medium width direction, and
• comparing a value R that is a ratio between the distance WL and the distance WR or a difference therebetween with a threshold R0 determined in advance.