Fixing Unit System; Overview/Configuration; Outline - Canon LBP5000 Series Service Manual

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Table of Contents

DC controller PCB

IC7

CPU

- CPU(IC1)

The CPU is a eight bit microcomputer in single chip with built-in ROM and RAM. It controls the following printer operations in response to the command from

the CPU(IC7).

1) Reverse motor and duplexing feed motor control

2) Reverse solenoid control

3) Top cover open sensor control

2.6 FIXING UNIT SYSTEM

2.6.1 Overview/Configuration

2.6.1.1 Outline

LBP5000 / LBP5100

The following is a diagram of the circuit used to control the temperature of the fixing heater.

The machine uses an on-demand fixing method, and the fixing unit is constructed as follows:

Thermal fuse

Fixing pressure rolle r

Sub ther mistor: TH2

(contact type)

Fixing uni t

- Fixing Heater

The fixing heater is a ceramic heater used to heat the fixing film. It has a single source of heat.

- Thermistor (TH1, TH2)

The thermistors are used to check the fixing temperature. The machine's fixing assembly uses 2 thermistors.

- Main thermistor (TH1): contact type thermistor

TH1 is in contact with an area of the fixing heater (around the middle), and is used to monitor the temperature of the heater.

- Sub thermistor (TH2): contact type thermistor

TH2 is in contact with the edge of the fixing heater, and is used to monitor the temperature of the edge of the fixing heater.

- Thermal fuse

The thermal fuse is used to prevent overheating of the fixing heater. The fuse is mounted around the middle of the fixing heater.

The temperature of the fixing assembly is controlled by the fixing control circuit and the fixing heater safety circuit using the foregoing items in response to the

instructions from the CPU (IC7) on the DC controller PCB

Duplexing driver PCB

IC1

CPU

F-2-34

Fixing film uni t

Fixing heater

FIXING HEA TER

Fixing film

Main ther m istor: TH1

(contact type)

FIXING TEMPERA TURE DETECTION signal s