II-23
2.5.3
Developing
Developing causes the toner to be attracted to the electrostatic image on the drum so as
to transform it into a visible image.
The developer consists of a non-magnetic toner. The development roller is made of
conductive rubber and the supply roller which is also made of conductive sponge rotate
against each other. The toner is charged and carried from the supply roller to the
development roller. The toner adheres to the development roller and is conveyed to the
drum at an even thickness controlled by the blade. The toner is nipped between the
development roller and the drum and developed onto the latent image on the drum. The
electrostatic field between the drum and the development roller, which is DC-biased from
the high-voltage power supply, creates the electrostatic potential to attract toner particles
from the development roller to the latent image area on the drum surface.
Fig. 2.30
2.5.4
Transfer
(a)
Transfer process
After the drum has been charged and exposed, and has received a developed
image, the toner formed is transferred onto the paper by applying a negative
charge to the backside of the paper. The negative charge applied to the paper
causes the positively charged toner to leave the drum, and adhere to the paper. As
a result, the image is visible on the paper.
(b)
Cleaning process of transfer roller
If the toner is not transferred onto the paper perfectly, it is possible that there may
be residual toner on the drum which will adhere to the transfer roller. The transfer
voltage charges to a positive voltage during non-printing rotation of the drum.
Therefore the transfer roller is cleaned by returning the positive charged toner
adhered on the transfer roller onto the photo-conductive drum.
(a) Transfer process [ON]
(b) Cleaning process [ON]
Drum
Erase lamp
(a) Collecting process
(b) Discharging process
Cleaning roller
Development roller
DC-bias
SR-bias
Supply roller
Develop housing
Auger
Separator
Blade
Transfer roller
Toner
Summary of Contents for HL-1070 - B/W Laser Printer
Page 1: ......
Page 20: ...II 4 Fig 2 4 ...
Page 24: ...II 8 1 3 5 DRAM Four 16Mbit DRAM x 16bit are used as the printer memory Fig 2 7 ...
Page 28: ...II 12 1 3 11 Engine I O Fig 2 14 and 2 15 show the engine interface circuit Fig 2 13 ...
Page 29: ...II 13 Fig 2 14 ...
Page 64: ...III 24 4 PACKING Fig 3 39 Documents Accessories Carton Pad Pad PE sheet Bag Pad Pad Carton ...
Page 96: ...CODE UK3958 000 B48K302 1CIR NAME A 3 Appendix 3 Main PCB Circuit Diagram 1 5 ...
Page 97: ...CODE UK3958 000 B48K302 1CIR NAME A 4 Appendix 4 Main PCB Circuit Diagram 2 5 ...
Page 98: ...CODE UK3958 000 B48K302 1CIR NAME A 5 Appendix 5 Main PCB Circuit Diagram 3 5 ...
Page 99: ...CODE UK3958 000 B48K302 1CIR NAME A 6 Appendix 6 Main PCB Circuit Diagram 4 5 ...
Page 100: ...Appendix 7 Main PCB Circuit Diagram 5 5 CODE UK3958 000 B48K302 1CIR NAME A 7 ...
Page 101: ...Appendix 8 Driver PCB Circuit Diagram CODE UK3634000 B48K280CIR NAME A 8 ...
Page 106: ...Appendix 13 SR PCB Circuit Diagram CODE UK3653000 B48K284CIR NAME A 13 ...
Page 107: ...Apr 98 54U011BE0 PARTS REFERENCE LIST MODEL HL 1070 R LASER PRINTER ...
Page 241: ...APPENDIX A 11 HP LaserJet 6P EPSON FX 850 IBM Proprinter XL EPSON FX 850 PC 850 ...
