charging bias is applied to the primary charging roller to keep a negative potential on the drum
surface.
Figure 1-14
Primary charging
Primary charging roller
Photosensitive drum
Primary charging bias
Step 2: Laser-beam exposure
The laser-beam strikes the surface of the photosensitive drum to neutralize the negative charge. An
electrostatic latent image forms where the negative charge was neutralized.
Figure 1-15
Laser-beam exposure
Laser beam
Photosensitive drum
Development block
Toner adheres to the electrostatic latent image on the photosensitive drum, which becomes visible.
Step 3: Developing
Toner acquires a negative charge from the friction that occurs when the developing roller rotates
against the developer blade. The developing bias is applied to the developing roller to make a
difference in the electric potential of the drum. The negatively charged toner is attracted to the latent
26
Chapter 1 Theory of operation
ENWW
Summary of Contents for LASERJET ENTERPRISE MFP M725dn
Page 1: ...LASERJET ENTERPRISE MFP M725 Troubleshooting Manual M725z M725dn M725f M725z ...
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Page 3: ...HP LaserJet Enterprise MFP M725 Troubleshooting Manual ...
Page 6: ...iv Conventions used in this guide ENWW ...
Page 32: ...xxx ENWW ...
Page 142: ...110 Chapter 1 Theory of operation ENWW ...
Page 457: ...4 Close the fuser jam access cover 5 Close the fuser door ENWW Clear jams 425 ...
Page 475: ...1 Lift the document feeder latch 2 Open the document feeder cover ENWW Clean the product 443 ...
Page 516: ...484 Appendix A Service and support ENWW ...
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