| 摘要 |
<P>PROBLEM TO BE SOLVED: To adjust tension applied to a belt-like image carrier at an operation stop even when an image forming apparatus is in operation and to securely prevent the belt-like image carrier from naturally being curled. <P>SOLUTION: A spring 20 which applies a biasing force to a tension roller 8a and a cam 21 are arranged. When a large-diameter side of the cam 21 comes to the side of the spring 20, the spring 20 is compressed and the tension applied to an intermediate transfer belt 8 becomes large. When a small-diameter side of the cam 21 faces the spring 20, the compression quantity of the spring 20 becomes small and the tension applied to the intermediate transfer belt 8 becomes small. A couple of cams 21 are fitted to a shaft 22 and press the bearing of the tension roller 8a. A spring clutch 23 is fitted to one end of the shaft 22 and a solenoid 24 rotates it by a half. The cam 21 moves in a direction wherein the spring 20 is compressed when the solenoid 24 turns on and moves in a direction wherein the spring 20 is not compressed when off. <P>COPYRIGHT: (C)2003,JPO |
