| 摘要 |
PROBLEM TO BE SOLVED: To detect an adequate replacement period with a simple and inexpensive constitution. SOLUTION: A current flowing in a motor 28 for rotating and driving a pair of rollers 22 and 24 is detected by a current sensor 29 and a fixing device is decided to be replaced, when the current is larger than a preset threshold. The current flowing in the motor 28 is influenced by the change in the torque rotation and drive of the pair of rollers 22 and 24. This torque becomes larger with the deterioration in passage of time of the pair of rollers 22 and 24, so that the adequate replacement period can be decided by setting the current equivalent to that of the time of the deterioration limit allowed to the pair of rollers to the threshold. It has a simple structure and is inexpensive, since only the current flowing in the motor 28 is tested. |
