| 摘要 |
<P>PROBLEM TO BE SOLVED: To correctly controls belt speed even in the event that a malfunction occurs in any of sensors which detect the belt speed. <P>SOLUTION: An intermediate transfer belt 10 is rotatably stretched between a drive roller 9 and two follower rollers 15 and 16. A scale 5 is formed by marking a large number of graduations over the entire circumference of the belt 10. Two sensors 6A and 6B are disposed for reading the scale 5. Even in the event that any one of the sensors malfunctions, a control device 70 accurately corrects and controls the belt speed based on information about the scale 5 read by the other sensor that is not malfunctioning. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
