APPARATUS FOR AND METHOD OF CONTROLLING THE TEMPERATURE OF A HOT ROLL FUSER IN A XEROGRAPHIC MACHINE

摘要

When a xerographic machine is switched on, a hot roll temperature control system initiates heating of the roll to a first temperature 21. At the end of a first predetermined period (44) from switch-on, if the roll has not reached the first temperature, indicating that the machine has been started from cold, the control system initiates heating of the roll to a second, higher, temperature 45. If the switch-on is after a temporary period of non-use of the machine, the hot roll will reach the first temperature within the first period, in which case that temperature is maintained. At the end of a second period (46), if the second temperature is being employed, then it is reduced to the first temperature. The machine senses whether first or second, larger, copy sheets are to be used and, whenever the larger sheets are used, increases the current roll temperature by a predetermined amount (55).