Canon i-SENSYS LBP5300 Series, Service Manual

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Chapter 2
2-34
T-2-4
The video controller specifies the each duplexing print operation. However, it cannot specify the operation other than the printable paper size (A4, LTR, and legal)
and the print mode (normal, thin paper, thick paper, gloss paper) for the duplexing print.
2.6 FIXING UNIT SYSTEM
2.6.1 Overview/Configuration
2.6.1.1 Outline
0013-8361
/ i-SENSYS LBP5360 / i-SENSYS LBP5300
The fixing control circuit is to control the fixing heater temperature in the fixing unit.
This printer utilizes the ceramic heater fixing method and the fixing unit is constituted as shown below.
F-2-45
- Fixing heater (H1):
A ceramic heater for heating the fixing sleeve.
The heater has one piece of U-shaped heating element on the back of heating surface.
- Thermistors (TH1, TH2):
The fixing unit of this printer incorporates two thermistors for the fixing temperature detection.
- Main thermistor (TH1): Contact type
The TH1 is for the print temperature control and the between-sheets temperature control. It touches the inside surface of the fixing sleeve at the center and
detects the fixing sleeve temperature.
- Sub thermistor (TH2): Contact type
The TH2 is for detecting abnormal temperature rise at both ends of fixing heater, the initial rotation temperature control, and the start-up temperature control.
It is in contact with the one-end of the fixing heater and detects the fixing heater temperature.
- Thermoswitch (TP): Non-contact type
The thermoswitch is for preventing the fixing heater from rising temperature abnormally high.
The thermoswitch is equipped above the center of the fixing heater.
If the fixing heater temperature rises abnormally high, the contact gets open to cut off the power supply to the heater.
These temperature controls of the fixing unit are performed by the fixing control circuit and the fixing heater safety circuit according to the commands from the
CPU (IC1001) in the DC controller.
Paper size Duplexing print operation
A4/LTR
Single sheet operation
Dual sheet operation
Alternating complex operation
Legal Single sheet operation
Fixing sleeve
Main thermistor: TH1
(contct type)
Sub thermistor: TH2
(contct type)
Fixing pressure roller
Fixing unit
Thermoswitch: TP
(Non-contact type)
DC controller PCB
Fixing heater
Low-voltage power
supply unit
FIXING HEATER
DRIVE signal
FIXING TEMPERATURE signal
Fixing heater
safety circuit
IC1001
CPU