| 摘要 |
PURPOSE:To enable sure detection of the arrival of a photosensitive body at the joint position and adequate setting of a timing for image formation by detecting the change in the thickness of a belt-like photosensitive body by a displacement member which is brought always into contact with the surface of the photosensitive body. CONSTITUTION:A detecting roller 21 is provided so as to contact always the surface at the end of a belt-like photosensitive body 1 by means of a spring 24 with a shaft 25 as a center and since the contact position thereof is on a roller 3, the chang in the thicness of the belt 1 can be surely detected. When the joint 18 of the belt 1 arrives, the roller 21 is lifted and a switch 26 is turned on. The timing is counted by the cooperative operation with a pulse disc 27 provided to the shaft 2. The joint position is thus detected and the adequate timing for image formation with the body 1 is set. |
