Gp 5.15 Exit Assembly And Fuser - Xerox DocuPrint N2025 Service Manual

GP 5.15 Exit Assembly and Fuser

The Fuser Assembly includes the components for fusing (to permanently fix the toner image on
the paper by heat and pressure) and those for ejecting the printed sheets out of the printer. In
this manual, only the components for fusing and associated components are often referred to
as the Fuser. Figure 1 & Figure 2
Heat Roll –
A hollow, surface-coated metal tube that is heated by the Heater Rod inside it and applies heat
to the paper passing between itself and the Pressure Roll. The heat melts the toner on the
paper.
Pressure Roll –
A solid, sponge rubber-coated metal shaft that presses the paper between itself and the Heat
Roll. The pressure helps bond the toner to the paper.
Heater Assembly –
Consists of a Heater Rod that is a lamp with a heat generating coil sealed in a quartz glass
tube and the connectors attached to the ends of the Heater Rod. The Heater Rod is located
inside the Heat Roll and heats the Heat Roll.
Temperature Sensor Assembly –
A resistor (thermistor) whose resistance varies sharply in a known manner with the tempera-
ture. This sensor is held in contact with the Heat Roll surface and monitors the temperature
thereof. The signal from this sensor is used to maintain the temperature of the Heat Roll sur-
face within the specified range by switching the power to the Heater Rod on and off. The signal
is also used for the first-stage overheat protection.
Thermostat –
Connected in series with the Heater Rod. The Thermostat functions as the second-stage over-
heat protection. If the first stage fails to prevent a fuser overheat, the Thermostat opens the
power supply circuit to the Heater Rod.
Thermal Fuse –
Connected in series with the Heater Rod. The Thermal Fuse functions as the third-stage over-
heat protection. If both the first and second stages fail to prevent a fuser overheat, the Thermal
Fuse opens the power supply circuit to the Heater Rod.
Fuser Stripper Fingers –
In conjunction the non-stick coating of the Heat Roll to peel the leading edge of the paper from
the Heat Roll to prevent the paper from winding around the Heat Roll.
Heat Roll Diode –
Initial Issue
DocuPrint N2025/N2825
There is a negative charge that builds up on the Heater Rod. This charge can disturb the toner
image on the paper during fusing. The Heat Roll Diode flows the charge to frame ground.
Exit Sens –
Detects the arrival and departure of the paper at and from the detection point in the exit area
after the Fuser.
Stack Full Sensor –
Detects when the Delivery Tray is full of printed sheets.
Exit Gate –
When the 500 Sheet OCT Assembly is installed, the Exit Gate is depressed by the Exit Gate
Solenoid Assembly and guides the paper coming out to the fuser into the OCT Assembly.
02/2000
6-69
General Procedures / Information
GP 5.15