Ricoh D109, Обучение по обслуживанию

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S-C4L Training
38
Slide 38
Charge Roller Voltage Correction
ID sensor
pattern
ID Sensor Pattern
Charge Voltage
Laser Diode
Development Bias
ID Sensor Output
On
Off
Drum Potential
Development
bias pattern
Sub-scan direction
Charge Roller Voltage Correction
ˆ
Voltage transfer from the charge roller to the drum decreases as the ambient
temperature and humidity increase. The machine checks the charge transfer,
and adjusts the charge roller voltage when required.
ˆ
Checks are done on initial warm-up. If the machine is set to low-power or auto-
off mode for more than 4 hours, a check will be done when the machine wakes
up.
Procedure:
ˆ
Right after the machine creates the ID sensor pattern for toner density control,
the development bias pattern is created.The development bias is decreased to –
400 V.
ˆ
The ID sensor measures the development bias pattern’s density (Vsdp) and the
bare drum’s voltage (Vsg).
ˆ
The FCU compares the results and adjusts the roller voltage accordingly.
‰
Vdsp/Vsg > 0.95: Decreases the negative charge on the charge roller by
+50 V.
‰
Vdsp/Vsg < 0.90: Increases the negative charge on the charge roller by –50
V.
ˆ
Use SP 2221 to see the current ID sensor values.