Canon I-Sensys LBP5050, Руководство по обслуживанию

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Chapter 2
2-14
T-2-5
3) Paper interval temperature control
This control is to bring the fixing heater temperature lower than the fixing temperature at paper interval to prevent the pressure roller from overheating during
continuous printing in low speed mode at paper interval.
Temperature during paper interval is changed corresponding to the distance and paper type.
2.6.3 Protective Functions
2.6.3.1 Protective function
0018-6520
LBP5050N / LBP5050
The protective function detects an abnormal temperature rise of the fixing unit and interrupts power supply to the fixing heater.
The following three protective components prevent an abnormal temperature rise of the fixing heater:
- DC controller
- Fixing heater safety circuit
- Thermal fuse
1) DC controller
The DC controller monitors the detected temperature of the thermistor located at the center of the fixing heater. The DC controller sets the FIXING HEATER
DRIVE (FSRD+, FSRD-) signals to inactive and releases the relay to interrupt power supply to the fixing heater under the following condition:
- Thermistor: 230 deg C or higher
2) Fixing heater safety circuit
The fixing heater safety circuit monitors the detected temperature of the thermistor located at the center of the fixing heater. The fixing heater safety circuit
releases the relay to interrupt power supply to the fixing heater under the following condition:
- Thermistor: 240 deg C or higher
3) Thermal fuse
When the temperature of the fixing heater rises abnormally high and the detected temperature of the thermal fuse is the following condition, the fuse blows to
interrupt power supply to the fixing heater:
- Thermal fuse: 226 deg C or higher
2.6.3.2 Fixing unit failure detection
0018-6522
LBP5050N / LBP5050
The DC controller determines a fixing unit failure, sets the FIXING HEATER DRIVE (FSRD+, FSRD-) signals to inactive, releases the relay to interrupt power
supply to the fixing heater and notifies the main controller of a fixing unit failure when it encounters the following conditions:
1) Start-up failure
- If the detected temperature of the thermistor does not reach 40 deg C within a specified period from the heater energization during the wait period.
- If the detected temperature of the thermistor does not reach 70 deg C within a specified
period after it once reaches 40 deg C after the heater energization during the wait period.
- If the detected temperature of the thermistor does not reach the targeted temperature within a specified period under the heater temperature control during the
initial rotation period.
2) Abnormal low temperature
- If the detected temperature of the thermistor is kept 100 deg C or lower for a specified period under the heater temperature control during the print period.
3) Abnormal high temperature
- If the detected temperature of the thermistor is kept 230 deg C or higher for a specified period.
4) Fixing heater drive circuit failure
- If the specified count of the ZERO CROSSING signal is not detected within a specified period after the printer is turned on.
- If the ZERO CROSSING signal is not detected for a specified period during the print period after the signal is once detected after the printer is turned on.
2.7 EXTERNAL AND CONTROLS SYSTEM
2.7.1 Power Supply
2.7.1.1 Power Supply
2.7.1.1.1 Low-voltage power supply
0018-6514
LBP5050N / LBP5050
The low-voltage power supply and the fixing power supply convert AC power from the power receptacle into DC power to cover the DC loads.
- Low-voltage power supply:
Generates DC power required in the printer
- Fixing power supply:
Supplies AC power to the low-voltage power supply
Controls the fixing heater temperature in the fixing unit
Speed Paper type Setting on driver 1st temperature to 5th temperature
6/5 speed
(monochrome) Plain paper (75 to 90 g/m2) Plain paper 183 to 175
Thin paper (60 to 74 g/m2) Plain paper L 164 to 130
1/1 speed (color) Plain paper (75 to 90 g/m2) Plain paper 168 to 156
Thin paper (60 to 74 g/m2) Plain paper L 168 to 150
3/4 speed Thick paper (91 to 120 g/m2) Thick paper 1 163 to 148
Thick paper (121 to 163 g/m2) Thick paper 2 168 to 159