Patent ID: 8559072

Claim:
An image reading apparatus comprising: a light emitting element array that includes a plurality of light emitting elements arranged in line in a first scan direction of a document; a guiding unit that guides light entering from the light emitting element array, and that emits the light toward a reading position of the document while diffusing the light; a light receiving unit that receives reflected light from the reading position irradiated with the light from the light emitting element array through the guiding unit; and a scan unit that moves the reading position of the document in a second scan direction, the reading position being a position read by the light receiving unit, wherein the guiding unit includes an input face for receiving the light from the light emitting element array, and an output face for emitting the light, a length in the first scan direction of the output face is set larger than a length of the document located at the reading position, and positions of edges in the first scan direction of the output face are located outside respective positions of edges in the first scan direction of the document, a length in the first scan direction of the input face is set smaller than the length in the first scan direction of the output face, and positions of edges in the first scan direction of the input face are located inside the respective positions of edges in the first scan direction of the output face; and the length in the first scan direction of the input face is set larger than a length of the light emitting element array, and positions of edges in the first scan direction of the light emitting element array are located inside the respective positions of edges in the first scan direction of the input face, and the output face has asperities that are formed at an interval smaller than an interval at which the plurality of light emitting elements are arranged in the light emitting element array.