| 摘要 |
PROBLEM TO BE SOLVED: To lighten and reduce maintenance work and also to prevent a cleaning member from being overdriven and causing imperfect cleaning, by controlling the drive of the cleaning member for an auxiliary transfer-plate based on the drive current and drive time of a driving device. SOLUTION: A cleaning mechanism for an auxiliary transfer-plate 1 is composed of a cleaning member 2, a motor 4 for driving the cleaning member 2, and a spiral shaft 3 connected to the motor 4. Normally, the cleaning member 2 is in an initial position. However, taking account of the case in which a power source is turned off during an operation, or the like, a monitor timer is started first and the motor 4 is CCW driven to perform the operation of returning it to the initial position. At the time, in the DC motor 4 or the like, a start current which is generally equal in current value to a lock current flows for a moment. When the time needed to detect the lock current is short, the start current is erroneously recognized as the lock current, therefore it is necessary that the time needed to detect the lock current be taken sufficiently longer than the time during which the start current flows. In the case the lock current is detected, the device recognizes that it reaches the opposite side. |
