| 摘要 |
PROBLEM TO BE SOLVED: To enable highly accurate positioning between an exposure optical system and an image forming body and attain an excellent image by supporting the image forming body and an image exposure means holding member by the use of a supporting member based on first and second fitting parts as a reference. SOLUTION: The receiving part 112a of the rear flange 112 of a photoreceptor drum 10 is fitted to a bearing 141 held by the holding part 103a as the first fitting part of the rear plate 103 of a casing 101. Then, a bearing 143 force-fitted to the receiving part 111a of the front flange 111 of the drum 10 is fitted to a holding part 102a as the first fitting part provided on the front plate 102 of the casing 101. In a state where a holding member 20 provided with the exposure optical system 12 is included in the drum 10, a shaft part 23 is fitted/fixed into a shaft hole 103b as a fixing part of the second fitting part provided in the center position of the holding part 103a. Moreover, the end part 24 of a disk part 22 is fitted/fixed to the fixing part 102b as the second fitting part provided concentrically with the holding part 102a. |
