| 摘要 |
PURPOSE:To improve the efficiency of illumination, by using a light source containing a light shielding layer having a slit on its upper surface and then setting the light source at a place close to an original. CONSTITUTION:A light source 16 is formed by unifying a plasma display panel containing a light shielding layer 20 having a slit 19 on its upper surface, a light emitting source of a diffusing organic EL, a thin film EL, etc. or a light emitting diode array chip at both sides of the moldless slit 19 into a semicylindrical shape with the transparent plastic so as to ensure the linear light emission. Such light source 16 is set close to an original 17. The light reflected from the original 17 formed into an image on a detector 15 through the slit 19 and a light guide system 14, then the contrast of the image is read. In this case, the light going upward is cut off by the layer 20 and only the lower part is illuminated. Thus the undesired light is never made incident to the system 14. Furthermore it is possible to set the original close to the source 16 to increase the efficiency of illumination. |
