An image reading apparatus includes an image reader, an image adjuster and an execution controller that causes the image reader to read an adjustment document and causes the image adjuster to adjust image data generated by the image reader. A latex vinyl impregnated flexible backing paper is affixed by a polyurethane resin adhesive to a back side of the slats to accurately hold the slats as a panel. Each power supply has an associated monitoring circuit that monitors the voltage drop across its OR-ing diode. Further, a cyclic redundancy check encoder is supplied to encode the input signal according to a CRC code.