| 摘要 |
PROBLEM TO BE SOLVED: To perform lancing by comparatively weak force and to reduce deformation caused in a cylinder after lancing by making the lanced part of the cylinder thinner in thickness than original thickness. SOLUTION: A photoreceptor drum 7 is provided with a gear flange 16 as a drum flange. The stepped part 7g of the drum 7 has the same inside diameter as an intermediate part 7c, and has the outside diameter smaller than the intermediate part 7c. Thus, the stepped part (thin part) 7g is made thinner in thickness than the intermediate part 7c. Therefore, even in the case shearing force perpendicular to the axis is exerted on a drum cylinder 7d, an influence caused by a situation that the stepped part 7g is thin is not exerted on the intermediate part 7c and strength and rigidity become sufficient. In a stage for lancing the end of the cylinder 7d, the gear flange 16 is made to enter the end of the cylinder 7d of the drum 7. Then, a part of the stepped part 7g is lanced toward a recessed part 16c formed on the gear flange 16. The gear flange 16 is coupled with the end of the cylinder 7d. |
