| 摘要 |
PURPOSE:To secure a stable amount of incident light on an optical sensor, by controlling an amount of light, which is projected on the surface of an original that passes a window part, or the amount of light, which is inputted in the optical sensor, in response to a distance from the optical sensor. CONSTITUTION:Three parts 190A-190C, whose dimensions are increased with the increase in distances from an optical sensor 8, are formed on an input window 190. Since the dimensions are increased in response to the distances from the optical sensor 8, the amounts of light passing the windows 190A-190C increase in this sequence. Thus, with the increase in distance l between the optical sensor part 8 and the surface of the original, i.e., the length of a light path, the surface of the original is irradiated with the large amount of the light. As a result, the amount of the light, which is inputted in the optical sensor part 8 is compensated. |
