Chapter 99-29.2.2 Down Sequence 0006-6007iR2270 / iR2870 / iR3570 / iR4570 / / iR2270N / / iR2870N / / iR3570N / / iR4570N / iR2230 / / / iR3530 /Down sequence is to prevent the machine from operating when the temperature of the end portion of the fixing film exceeds a specific temperature as when usingsmall-size paper continuously. The details of the control are described below:1. The sub thermistor detection temperature is 275 deg C or more.2. Reduces the number of sheets passed by increasing the paper interval.3. Returns the number of sheets to the normal when the sub thermistor detection temperature is 265 deg C or less.9.3 Various Control Mechanisms9.3.1 Controlling the Speed of the Fixing Film9.3.1.1 Controlling the Fixing Film Speed in Response to Low Temperature 0006-6037iR2270 / iR2870 / iR3570 / iR4570 / / iR2270N / / iR2870N / / iR3570N / / iR4570N / iR2230 / / / iR3530 /As in the morning, driving the fixing film in a low-temperature environment without warm-up could cause the film to become displaced. In consideration of thisfact, the fixing motor is started up in phases (1/4 speed to 1/2 speed and then to normal speed).9.3.1.2 Controlling the Fixing Film Speed 0007-5124iR2270 / iR2870 / iR3570 / iR4570 / / iR2270N / / iR2870N / / iR3570N / / iR4570N / iR2230 / / / iR3530 /The rotation cycle of the fixing film is monitored to control the fixing motor to a specific speed.When the fixing film rotates and, as a result, the reflecting member positioned in the loop of the film approaches the speed sensor, the machine detects the rotationof the fixing film.F-9-2[1]Speed sensor[2]Reflecting member[3]Fixing film (driven by fixing motor)[4]Pressure roller[A]Paper feed direction[B]Speed sensor output[C]1 rotation of fixing filmTiming of ControlThe speed of fixing film rotation is monitored at all times after the fixing motor goes on and its speed reaches a specific value. The speed of the fixing motor is thencontrolled so that it remains at a specific level at all times.9.3.2 Controlling the Fixing Film Temperature9.3.2.1 Controlling the Power Supply in Response to Low Temperature 0007-5125iR2270 / iR2870 / iR3570 / iR4570 / / iR2270N / / iR2870N / / iR3570N / / iR4570N / iR2230 / / / iR3530 /In a low temperature environment, the heater is supplied with power before the fixing film is driven so as to soften the grease applied to the fixing film. The mech-anism of control is as follows:If the temperature of the fixing film detected by the thermistor is lower than a specific level, the heater is supplied with power for a specific period of time beforea normal start-up mechanism is initiated.If the temperature of the fixing film detected by the thermistor is higher than a specific level, the normal start-up mechanism is imitated.9.3.2.2 Controlling the Feeding in Response to Low Temperature 0007-5401iR2270 / iR2870 / iR3570 / iR4570 / / iR2270N / / iR2870N / / iR3570N / / iR4570N / iR2230 / / / iR3530 /In a low temperature environment, the feeding timing is changed according to the temperature detected by the environment sensor so as to enhance the fixing ca-pability. The details are described below.When the environment sensor detection temperature is 13 deg C or less, the feeding timing is delayed by 5000 msec.In thick paper mode, the feeding timing is not changed even if the environment sensor detection temperature is 13 deg C or less.9.3.2.3 Controlling the Power Supply at Start-Up 0006-6583iR2270 / iR2870 / iR3570 / iR4570 / / iR2270N / / iR2870N / / iR3570N / / iR4570N / iR2230 / / / iR3530 /When the thermistor detection temperature is 180 deg C or less, the power control to compensate for the heater, (varying according to input voltage and a heaterresistor value) is performed so as to raise the temperature of the fixing unit to the required temperature for fixing in a short time.1. starts 65% power supply.[C][2][B][A] [4][1][3]
