DRUM CHARGE
B044/B045/B046 6-30 SM
How Correction is Made
Immediately after creating the ID sensor pattern [A] used for toner density control
(☛ 6.12.4), the machine generates another pattern [B] for charge voltage
correction by intensifying the development bias (☛ 6.12.2) to –600 V. The laser
remains off, but a small amount of toner moves to the drum because of the slight
charge difference between the drum and development roller. The ID measures the
pattern's density (Vsdp) and the bare drum voltage (Vsg); the FCU compares the
difference and adjusts the roller voltage accordingly.
• If Vsdp/Vsg > 0.95: Change charge roller voltage by +50 V (less negative).
• If Vsdp/Vsg < 0.90 = Change charge roller voltage by –50 V (more negative).
NOTE: The current ID sensor readings can be viewed using SP2-221.
6.11.3 CHARGE ROLLER CLEANING
A cleaning roller [A] removes toner and debris that the roller picks up from the
drum.
B046D304.WMF
[A]
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