| 摘要 |
<p>The rolls (31, 32) of a hot roll fuser are normally closed at a predetermined time prior to the arrival of a copy sheet at the roll nip. If, however, the temperature of the backup roll (32) exceeds a predetermined value, the rolls are closed at a shorter time before the copy sheet arrival. A sensor (50) is coupled to threshold circuit (53) which applies enabling inputs to AND gates (64, 66). These gates receive timing signals from a counter and decoder system (71, 73, 74, 75) and, in accordance with the output from the threshold circuit (53) apply either an early or a late pulse to a fuser roll closure latch (78). Instead of directly measuring the backup roll temperature, the timing of opening and closing of the fuser rolls may be monitored to predict the temperature of the backup roll.</p> |
