Epson LG1-1070 Service Manual page 175

OPERATION PRINCIPLES
2.1 OVERVIEW OF PRINTER M E C H A N I S M OPERATION.. ............. 2-1
2.1.1 Printhead Mechanism .............................................................. 2-1
Carriage Movement Mechanism.. ........................................ 2-2
2.1.2
Paper Feed Mechanism.. ......................................................... 2-3
2.1.3
2.1.3.1 Paper Advance Mechanisms.. .................................... 2-3
2.1.3.2 Paper Insertion Entrances ........................................... 2-6
2.1.4 Ribbon Advance Mechanism ................................................. 2-10
2.2 POWER SUPPLY OPERATION ........................................................... 2-11
2.2.1 Power Supply Overview ......................................................... 2-11
Supply Circuit Operation.. ...................................................... 2-11
2.2.2
2.3 CONTROL CIRCUIT OPERATION ..................................................... 2-13
Control Circuit Operation Overview.. ................................. 2-13
2.3.1
2.3.2 Reset Circuit ............................................................................... 2-15
Sensor Circuits.. ......................................................................... 2-16
2.3.3
MOTOR, CR Drive Circuit.. .................................................... 2-17
2.3.4
MOTOR, PF Drive Circuit.. ..................................................... 2-18
2.3.5
Printhead Drive Circuit.. ......................................................... 2-19
2.3.6
Parallel Interface Circuit.. ...................................................... 2-20
2.3.7
EEPROM Control Circuit.. ...................................................... 2-20
2.3.7
LIST OF FIGURES
How the Printhead Works.. ................................................ 2-1
Figure 2-1.
Carriage Movement.. ............................................................. 2-2
Figure 2-2.
Figure 2-3. Paper-Thickness Gap LEVER, G, ADJUST
Movement.. ............................................................................... 2-2
Top Entrance Friction Feed.. ............................................... 2-3
Figure 2-4.
Push Tractor Operation ....................................................... 2-4
Figure 2-5.
Pull Tractor Operation.. ........................................................ 2-5
Figure 2-6.
Push-Pull Tractor Operation.. ............................................. 2-5
Figure 2-7.
LEVER, RELEASE Movement ............................................. 2-6
Figure 2-8.
Paper Path for Top Entrance Friction Feed.. ................ 2-6
Figure 2-9.
Paper Path for Rear Entrance Push Tractor Feed ...... 2-7
Figure 2-10.
Figure 2-11. Paper Path for Rear Entrance Push-Pull
Tractor Feed.. ...........................................................................2-7
CHAPTER 2
2-i
REV.-B