| 摘要 |
PURPOSE:To make the apparatus compact by providing a multibeam light source, a plurality of photodetecting elements and an image forming optical system integrally into one casing. CONSTITUTION:A photosensor 20 has a casing 29. A multibeam light source 21, an image forming lens 22 and an array 23 of photodetecting elements are fixedly provided in the casing 29. The light source 21 is comprised of a photodiode 24 and an off-axis micro Fresnel lens array 25 which divides the light projected from the diode 24 into four beams and projects the beams to different positions after collimating the same. The array 23 has many photodetecting elements. Moreover, the lens 22 forms an image of mainly the reflecting diffusing light from the document among the projecting light beams onto the corresponding photodetecting element. Visible light cut filters 26, 27 are provided on the upper surface of the casing 29. Accordingly, since the light source 21, lens 22 and array 23 are provided integrally in the casing 29, the apparatus becomes compact in size. |
