Fixing System In this unit, you will learn how the machine controls the fixing system so that a toner image is permanently fixed to print paper. At the same time, you will also study the construction and functions of the fixing assembly and the tasks of the service person.

To learn about the fixing assembly, go through the following topics

Outline of the Fixing System

　

○Purpose  : Here, we will study the components of the fixing system and the specifications associated with them.

　

1. Outline

The fixing system of a machine comes to play its role after the image formation process. When print paper arrives carrying a toner image, the fixing system permanently fuses it to the fibers of the paper.

The machine’s fixing system uses an on-demand fixing method.

The fixing system consists of a fixing film unit (1) and a pressure roller (2) among others, all constructed as a single entity. The fixing assembly is controlled by the DC controller, which heats a fixing heater at the start of printing for fixing of the toner image to print paper.

Take a look at the major components of the fixing system.

　

○Diagram of the Fixing Assembly (see photo: )

[1] Cleaning roller

[2] Pressure roller

[3] Fixing heater

[4] Main thermistor (TH1)

[5] Thermal switch (TP1)

[6] Fixing film

[7]Sub thermistor (TH2)

[8] Fixing film speed sensor (PS8)

2. Compatibility

The speed at which paper is moved differs between iR2270/2870 and iR3570/4570 Series machines, and the thickness of the fixing film and the diameter of the pressure roller also differ accordingly. To accommodate the differences, there are 2 types of fixing assemblies and assembly components without compatibility among them. These different types of fixing assemblies are provided with a means of preventing wrong installation. (For details, see “Tasks of the Service Person.”)

A higher speed requires the fixing film to be thicker and, consequently, the diameter of the pressure roller to be larger.

　

　

3. Specifications Associated with the Fixing System

Now, let’s take a look at the fixing system.

　

Fixing assembly 　 Fixing method on-demand 　 Fixing heater plate heater 　 Control temperature 180 dg C (at PSTBY) 　 Fixing drive control control of fixing film speed 　 Fixing temperature detection main thermistor:center of fixing heater sub thermistor:front end of fixing heater 　 Protective mechanisms thermistor:error temperature thermal switch:error temperature relay:error temperature 　 Separation claw no 　 Bias application fixing film:negative bias pressure roller:positive bias 　 pressure release mechanism pressure roller auto release mechanism 　 Cleaning mechanism cleaning roller