PROCESS CONTROL August 2006
6-86
Adjust Vpl
The LD power is adjusted in order to get to the target Vpl (the Vpl value after
correction for Vr)
After correction for Vr, the value of Vpl must be within ±5V.
Vpl (LD Power) Adjust Errors
SC Codes SP3821 Procon OK?
For More Details:
SC424~SC427 64 See "Process Control Troubleshooting" in
Section "4. Troubleshooting".
Vtref/Vtcnt Calibration
Vtref calibration: Calibrates Vtref to the value of Vt
Vtcnt calibration: If Vt is not within the range of 2 to 3 V, Vtcnt is changed to
bring it within this range.
This lets the machine use the results of the process control calculations to get the
correct toner amount.
There is no check for abnormal conditions at this step.
Process Control Gamma Correction
The following adjustments are done, based on the development gamma correction,
to achieve the target values (Vd, Vl, Vb)
• To adjust Vd (drum bias), the voltage of the charge roller is raised.
• To adjust Vl (laser power), the input current of the laser diodes is raised.
• To adjust Vb (development bias), the charge on the development roller is
increased.
At this time:
• Development gamma must be in the range 0.3 to 6.0.
• Development start voltage must be in the range –150 to 150 V.
Potential Control Errors
SC Codes For More Details:
SC410~SC417 See "Process Control Troubleshooting" in Section "4. Troubleshooting".