| 摘要 |
PROBLEM TO BE SOLVED: To improve the detection accuracy of original reflectance (reflection density) regardless of thickness of the original by arranging a light projector/receiver so as to sandwich the original and consisting the reflecting member of a fluorescent reflection panel coated with fluorescent pigment. SOLUTION: When conveying an original 2 through a measuring area to a prescribed position by an original conveying means, in the measuring area, the density of the original 2 is detected by using a light projector/receiver 11 and a reflecting member 30 which are arranged so as to sandwich the original 2. In this case, the reflecting member 30 is composed of the fluorescent reflection panel coating its face on the side of the light projector/receiver 11 with the fluorescent pigment composed of fluorescent dyes containing diaminostilbene, uranyl, thioflavin T and eosine, etc., as main components and further, the surface shape of this fluorescent reflection panel on the side of the light projector/receiver 11 is made into convex. Besides, the light projector/ receiver is provided with a floodlight 1 for illuminating the original in the middle of conveyance and a light receiver 5 for receiving reflected light flux fro the original or/and light flux transmitted through the original, reflected on the fluorescent reflection panel and transmitted through the original again in the light flux from the floodlight 1. |
