II-29
2.5.2
Exposure stage
After the drum is positively charged, it is exposed to the light emitted from the laser
unit.
Fig. 2.32
The exposed area is the part to be printed. The surface potential of the exposed
area is recreated forming an electrostatic image to be printed.
1 Cycle of drum
Surface Potential (V)
+1000
+700
+400
+300
1
2
3
4
(a)
(b)
Time
1
2
3
4
Primary charging
Laser beam exposure and developing
(a) Unexposed area
( Non image area )
(b) Exposed area
( Image area )
Transfer the image to paper
Erase the residual potential
Drum
Sleeve
Fig. 2.33
Laser Beam
Drum
Paper
Laser beam
f
lens
Polygon mirror
Motor
Lens
Laser diode
Laser detector
Содержание HL-720
Страница 1: ...SERVICE MANUAL MODEL HL 720 730 730Plus R LASER PRINTER ...
Страница 36: ...II 19 1 3 10 Engine I O HL 720 Fig 2 21 shows the engine interface circuit Fig 2 21 ...
Страница 37: ...II 20 HL 730 730Plus Fig 2 22 shows the engine interface circuit Fig 2 22 ...
Страница 61: ... Fig 3 18 2 4 1 1 1 ...
Страница 92: ...SERVICE MANUAL MODEL HL 760 R LASER PRINTER ...
Страница 109: ...II 8 1 3 4 DRAM Two 4M bit DRAMs x 16bits are used as the RAM Fig 2 6 ...
Страница 113: ...II 12 1 3 10 Engine I O Fig 2 12 shows the engine interface circuit Fig 2 12 ...
Страница 114: ...II 13 1 3 11 Paper Feed Motor Drive Circuit Fig 2 13 ...
Страница 133: ...Appendix 2 Main PCB Circuit Diagram 1 3 CODE UK3227000 B48K272CIR 1 3 NAME ...
Страница 134: ...Appendix 3 Main PCB Circuit Diagram 2 3 CODE UK3227000 B48K272CIR 2 3 NAME ...
Страница 135: ...CODE UK3227000 B48K272CIR 3 3 NAME Appendix 4 Main PCB Circuit Diagram 3 3 ...