| 摘要 |
PURPOSE:To simplify a measuring mechanism by dividing a printing original film into plural columns, and measuring simultaneously the density of scanning of each column by using an individual photoelectric converting element with regard to each column. CONSTITUTION:In case when a fluorescent lamp 14 in a projecting part has been turned on, positions 11a, 11b and 11c of a diffusion plate 11 are irradiated directly by the fluorescent lamp 14, and an illuminance being in inverse proportion to a square of a distance from the fluorescent lamp 14 is given. The illuminance becomes the maximum in the position 11b, and becomes the minimum in the positions 11a, 11c. Also, the diffusion plate 11 is irradiated by a reflected luminous flux, too, by a reflecting semicylinder, the reflected luminous flux by an end part 13c of a semi-circular arc of the reflecting semi-cylinder irradiates a position 11d on the diffusion plate by the reflected luminous flux for forming an angle of reflection theta3b which is equal to an incident angle theta3a, and the maximum reflection illuminance is generated in a position 11e on the diffusion plate 11. In the same way, the reflected luminous flux by the position 11e irradiates a position 11f on the diffusion plate 11 by the reflected luminous flux for forming an angle of reflection theta4 which is equal to an incident angle theta4. |
