Patent ID: 8169671

Claim:
A lighting unit, comprising: a light source section wherein a plurality of light-emitting sources are arranged in a direction perpendicular to a direction of each light-emitting optical axis of each light-emitting source and linearly at predetermined intervals; and a reflecting section which reflects light emitted toward a direction along a document mounting surface from the light source section arranged along the document mounting surface toward an irradiated region of the document mounting surface, the reflecting section including: a first reflecting surface disposed closer to the light source section than to the irradiated region; and a second reflecting surface disposed more distant from the light source section than from the irradiated region, wherein a ratio of a projected area of the first reflecting surface to a projected area of the second reflecting surface is approximately equal to a reciprocal of a ratio of the square of a distance from the light source section to the first reflecting surface to the square of a distance from the light source section to the second reflecting surface.