Canon imageCLASS LBP6780dn - Fixing System

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Technology > Fixing System > Fixing control circuit > Fixing temperature control
Technology > Fixing System > Fixing control circuit > Fixing temperature control
Fixing System
Fixing control circuit
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Outline
The xing control circuit controls the temperature in the xing unit. The printer uses an on-
demand xing method.
The Figure below shows the conguration of the xing control circuit.
TH2
TH1
TP1
H1
FIXING TEMPERATURE signal
FIXING HEATER CONTROL signal
Fixing heater safety
circuit
DC controller
Fixing control circuit
Pressure roller
Fixing film
Fixing heater control
circuit
Engine controller
• Fixing heater (H1): Heats the xing lm
• Thermistor (TH1, TH2): Detects xing temperature (Contact type)
• Main thermistor (TH2): Controls temperature in the xing unit (Contact type)
• Sub thermistor (TH1): Detects one-sided temperature rise of the xing unit Controls
temperature in the xing unit (Contact type)
• Thermoswitch (TP1): Prevents an abnormal temperature rise of the xing heater (Contact
type)
These temperature controls in the xing unit are performed by the xing heater control circuit
and the xing heater safety circuit according to the commands from the DC controller.
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Fixing temperature control
The xing temperature control maintains the temperature of the xing heater temperature.
The Figure below shows the block diagram of the xing temperature control.
ZEROX
TH1
TP1
H1
FSRD
RLYD
FSRTH2
RL1001
TH2
RL1002
FSRTH1
H1: Fixing heater
TP1: Thermoswitch
TH2: Main thermistor
TH1: Sub thermistor
Pressure roller
Fixing film
Fixing heater
control circuit
Fixing heater
safety circuit
DC controller
Engine controller
Fixing control circuit
Fixing unit
Relay control
circuit
Frequency
detection circuit
The DC controller monitors the FIXING TEMPERATURE (FSRTH1, FSRTH2) signals and
sends the FIXING HEATER CONTROL (FSRD) signal according to the detected temperature.
The xing heater control circuit controls the xing heater depending on the signal so that the
heater remains at the targeted temperature.
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