Phaser 7500 Printer Service Manual 2-19
Theory of Operation
Fusing
The toner image is fused to the paper by melting the toner on the paper and using
pressure to compress it.
• The toner image that was transferred from the Drum can be spoiled even by
just lightly touching it with a finger. The paper has to pass through the Fuser
(Fusing Unit: Fuser Assembly) to fuse this toner image to it.
• The Fuser of the printer has a Pressure Belt instead of a Pressure Roll. The Heat
Roll rotates, driving the Pressure Belt, which is driven by the friction. The
pressure system in the belt nips the belt and Heat Roll.
• The Heat Roll is heated by the Heater Lamp to melt the toner, while the nip
pressure between the Heat Roll and the Pressure Belt fuses the toner to the
paper.
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Pressure Belt
Heat Roller
Heater Lamp
Nip Section
Paper
Fuser Structure (Cross Section)
Heat Roller
Center Temperature Sensor
Paper Zone
Rear Temperature Sensor
Main Heater
Lamp
Sub Heater Lamp
Environment
Sensor
Rear
Thermostat 2
Thermostat 1
Front
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Fuser Structure (Side View)