| 摘要 |
PROBLEM TO BE SOLVED: To produce a photoconducting plate of good transparency and high brightness uniformity, so as to allow the mass production thereof. SOLUTION: A prototype model made of the same material as a photoconductor plate as a product is subjected to a sand blasting process, and at least one of the conditions of a scanning speed, a scanning pitch, a sand flowrate, blast pressure and a distance between a sandblast nozzle and machined surface, is changed, thereby forming a gradation pattern made of an infinite number of such micro recesses as independently invisible. A plating layer is formed on the outer surface of the prototype model and a mold is manufactured by use of the electrocasting method. Thereafter, the photoconducting plate as a product is formed by use of the mold, and a degradation pattern 12 made of recesses 12A is thereby formed on surface 11M. Also, the distribution density of the recesses 12A is increased according to departure from the sides 11A and 11B where primary illumination light is incident, thereby providing a uniform illumination zone. This production method uses a mold and is suitable for mass production. In addition, evaluation can be made by use of a prototype model. As a result, the repeated trial production of the mold is not needed. |
