METHOD OF CONTROLLING FUSER UNIT OF IMAGE FORMING APPARATUS

During warm-up of an image-forming apparatus such as a laser printer, the operation of a fuser unit contained therein is controlled by a method which includes the steps of: energizing a heater (310) in a heated roller (10) at substantially the same time as an initialisation process of the mechanical and electrostatic conditions of the machine is commenced in which process the heated roller (10) and a backup roller (12) are rotated together; stopping the rotation of the rollers (10, 12) after the initialisation process has been completed; monitoring the surface temperature of the heat roller (1) for a first predetermined period (T1 - T9) after the completion of the initialisation, and if the surface temperature has reached a set value within the first predetermined period, determining that the fuser unit (14) is ready for operation, and conversely, if the set value is not reached within the first predetermined period (T1 - T9), carrying out an additional warming-up process of rotating the heat roller (10) and the backup roller (12) again until the set value is reached, unless a second predetermined period (T6 - T1) has expired subsequent to the expiry of the first predetermined period (T1 - T9). By employing such a method, the mechanical and electrostatic stresses imposed on the process elements (216, 220, 226) of the apparatus during warm-up may be reduced.