Chapter 2
2-31
F-2-34
- 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
0010-6156
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:
F-2-35
- 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
M
M
DC controller PCB
Reverse motor
Duplexing feed motor
Top cover open sensor
Reverse solenoid
SL
IC1
CPU
IC7
CPU
Duplexing driver PCB
Fixing film
Main thermistor: TH1
(contact type)
Sub thermistor: TH2
(contact type)
Fixing pressure rolle
r
Fixing unit
DC controller PCB
Low-voltage power
supply unit
Fixing heater
Thermal fuse
Fixing film unit
FIXING HEA
TER
DRIVE signal
FIXING TEMPERATURE DETECTION signal
s
CPU
Fixing heater
safety circuit
IC7
Fixing
control
circuit
Summary of Contents for LBP5000 Series
Page 1: ...Feb 26 2007 Service Manual LBP5000 5100 Series...
Page 2: ......
Page 6: ......
Page 14: ...Contents...
Page 15: ...Chapter 1 PRODUCT DESCRIPTION...
Page 16: ......
Page 18: ......
Page 28: ......
Page 29: ...Chapter 2 TECHNICAL REFERENCE...
Page 30: ......
Page 33: ...Contents 2 8 3 2 Overview of the Block 2 39...
Page 34: ......
Page 74: ...Chapter 2 2 40 IC12 Logic IC Converts voltage levels Notation Name Description...
Page 75: ...Chapter 3 DISASSEMBLY AND ASSEMBLY...
Page 76: ......
Page 80: ......
Page 122: ......
Page 123: ...Chapter 4 MAINTENANCE AND INSPECTION...
Page 124: ......
Page 126: ......
Page 132: ......
Page 133: ...Chapter 5 TROUBLESHOOTING...
Page 134: ......
Page 136: ......
Page 141: ...Chapter 5 5 5 F 5 9...
Page 142: ...Chapter 5 5 6 F 5 10...
Page 149: ...Chapter 6 APPENDIX...
Page 150: ......
Page 152: ......
Page 161: ...Feb 26 2007...
Page 162: ......