| 摘要 |
PURPOSE:To achieve cost reduction and make reading speed higher by providing a cylindrical lens near the main scanning part and optically connecting the portion near the main scanning part and a photodetector with an optical transmission body having a divergent shape. CONSTITUTION:This method reads the original 0 being conveyed in the direction shown by an arrow by scanning the surface of said original by a laser beam L in the home position and detecting the light reflected from the original 0 with a photodetector 5, wherein a cylindrical lens 6 is provided near the main scanning part in such a manner that the direction having no imaging function parallels to the main scanning direction and the light entered the cylindrical lens 6 out of the reflected light of the original 0 convergently enters the incident end of a slit shape of an optical transmission body 7. The optical transmission body 7 is of the constitution in which the circumference of the core part of a refractive index n1 is coated by a clad part of a refractive index n2 (where n2<n1), thus the greater portion of the incident light is detected with the photodetector 5 efficiently. |
