Image sensor unit, paper sheet distinguishing apparatus, and image reading apparatus

An image sensor unit elongated in an X direction, comprising:

• two rod-like light guides elongated in the X direction, the two light guides being arranged such that surfaces on sides of the two light guides that are elongated in the X direction face each other, the two light guides being configured to emit light from light emission surfaces elongated in the X direction;
• two light sources configured to provide incident light to the respective light guides;
• an image sensor elongated in the X direction and configured to receive light from an object to be read;
• and
• a frame housing the two light guides,
• wherein:
• the two light sources are arranged such that the light incident on the respective light guides is incident on the respective light guides from surfaces of ends of the respective light guides facing the X direction,
• the two light guides are pressed to the frame by a plurality of holding members provided at intervals in the X direction, and
• a first holding member of the plurality of holding members pressing the light guides and a second holding member of the plurality of holding members pressing the light guides, which is a holding member of the plurality of holding members that is closest to the first holding member in the X direction, are arranged at locations deviated from each other in the X direction.