Patent ID: 7843612

Claim:
An image sensor unit having a frame storing: a linear illuminator that linearly illuminates a document; a rod lens array that is used to form an image of light reflected from the document irradiated by the linear illuminator; and a printed circuit board on which a light-receiving sensor that converts light whose image has been formed by the rod lens array into an electrical signal is mounted; wherein, in the frame, a lens storage compartment and a linear illuminator storage compartment that are formed for respectively storing and fixing the rod lens array and the linear illuminator are adjacently arranged substantially in parallel to each other in a longitudinal direction, with an inter-compartment portion formed in the frame interposed therebetween, at least one pin insertion opening is formed that extends from an inner wall of the lens storage compartment opposing the inter-compartment portion into an outside of the frame and through which a pressing pin is inserted, and in the inter-compartment portion, a face defining the lens storage compartment is formed as a vertical reference face with which a side plate of the rod lens array is brought into close contact for fixing, and a notch that is used for applying an adhesive to the side plate of the rod lens array and that is disposed corresponding to the pin insertion opening is formed so as to be open from the lens storage compartment to the linear illuminator storage compartment.