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4-9
4.2.2.2
Paper feeding and ejection mechanism
The paper feeding and ejection mechanism is driven by the paper feed motor (DC motor), located
on the rear left side of the engine unit, through the two PF timing belts and a gear train.
The rotational torque of the paper feed motor is transmitted via PF timing belt 135 to the PF roller
pulley. Engaged with the pulley, the paper feed roller rotates. In step 2 of paper feeding (as
described on the previous page), the paper feed roller rotates backwards to register the leading
edge of the paper being pulled in. Next, it reverses the direction of its rotation to feed the paper.
The rotation of the PF roller pulley is also transmitted via PF timing belt 160.5 to idle pulley gear
24/28. Engaged with the idle pulley gear, paper ejection gear 28B rotates so that the paper ejection
roller (urethane-coated) ejects the printed paper.
The idle pulley holder is spring-structured. The idle pulley applies tension to PF timing belt 160.5
and prevents the belt from deviating from its designated path.
On the outer side of the PF roller pulley is a PF encoder disk with a resolution of 300 dpi (0.084
mm pitch). Using this disk, the PF encoder sensor detects the rotational angle or speed of the paper
feed roller so that the controller can control the paper feeding position and speed. The PF encoder
sensor can output signals of two different phases, so the resolution can be a maximum of four
times 300 dpi.
Engine unit
Paper feed roller
Paper feed motor
Paper ejection roller
Paper ejection gear 28B
Idle pulley gear 24/28
PF timing belt 135
PF roller pulley
Idle pulley holder
(Supporting the idle pulley)
PF timing belt 160.5
PF encoder disk
PF encoder sensor
Summary of Contents for MFC-4820C
Page 1: ...FACSIMILE EQUIPMENT SERVICE MANUAL MODEL MFC4820C MFC4420C ...
Page 6: ...CHAPTER 1 PARTS NAMES FUNCTIONS ...
Page 13: ...CHAPTER 2 SPECIFICATIONS ...
Page 19: ...2 5 2 1 4 Environmental Conditions ...
Page 26: ...CHAPTER 3 SETTING UP OF THE MACHINE ...
Page 29: ...3 2 3 2 UNPACKING THE MACHINE The equipment consists of the following major components ...
Page 40: ...CHAPTER 4 THEORY OF OPERATION ...
Page 76: ...CHAPTER 5 ROUTINE MAINTENANCE ...
Page 84: ...CHAPTER 6 DISASSEMBLY REASSEMBLY ...
Page 114: ...6 29 6 1 11 Speaker 1 Pull the speaker and its spring out of the lower cover ...
Page 136: ...CHAPTER 7 MAINTENANCE MODE ...
Page 145: ...7 8 Scanning Compensation Data List ...
Page 160: ...7 23 1st sheet 2nd sheet Vertical Alignment Check Patterns and Head Skew Check Pattern ...
Page 162: ...7 25 Margin Check Patterns ...
Page 170: ...CHAPTER 8 ERROR INDICATION AND TROUBLESHOOTING ...
Page 197: ...MFC4820C MFC4420C Appendix 1 Serial No Descriptions ...
Page 205: ...App 2 4 Click Finish to return to Windows ...
Page 209: ...MFC4820C MFC4420C Appendix 3 EEPROM Customizing Codes ...
Page 212: ...MFC4820C MFC4420C Appendix 4 Firmware Switches WSW ...
Page 252: ...App 4 40 WSW48 to WSW50 Selector No Function Setting and Specifications 1 8 Not used ...
Page 253: ...MFC4820C MFC4420C Appendix 5 Re Packing Instructions ...
Page 255: ...App 5 2 2 Place the machine in the original box with the original packaging material ...
Page 256: ...MFC4820C MFC4420C Appendix 6 Wiring Diagram ...
Page 259: ...A Main PCB 1 5 ...
Page 260: ...A Main PCB 2 5 ...
Page 261: ...A Main PCB 3 5 ...
Page 262: ...A Main PCB 4 5 ...
Page 263: ...A Main PCB 5 5 ...
Page 264: ...B Driver PCB ...
Page 265: ...C NCU PCB ...
Page 266: ...D Control Panel PCB ...
Page 267: ...E Power Supply PCB ...