Uneven Density or Mottle
Problem
Uneven Density or Mottle
Solutions
1. Perform Secondary Transfer Voltage Adjustment.
• Use this feature to adjust the voltage ratio on the secondary bias transfer roll (2nd BTR). For heavy-weight paper, such as 220 g/m2 or greater, the 2nd BTR is where the image is transferred from the belt to the paper. However there are times when it is also used with lightweight paper.
• This feature is accessed from > > > > .
• The Secondary Transfer Voltage Adjustment procedure can be performed by selecting Auto or Manual.
Note: An automatic adjustment fixes most image quality issues. Always perform the Auto procedure before performing the Manual adjustment.
▪ Auto: The adjustment is done automatically by the press. It eliminates the need for you to interpret printed targets and enter adjustment values manually. This saves time and avoids errors.
▪ Manual: The user must manually perform the adjustment, including printing test patterns, interpreting the printed targets on those patterns, and then manually entering the adjustment values.
Tip:
Use the Manual adjustment option only when the Auto adjustment does not provide the desired output.
2. If the issue is observed on the tail edge of the printed output and is not corrected by performing a Secondary Transfer Voltage Adjustment, change the Transfer Output Adjustment for Trail Edge setting.
• Use this feature to adjust the voltage ratio on the secondary bias transfer roll (2nd BTR); this is where the image is transferred from the belt to the paper.
• This feature is accessed from > > > > .
• Decrease the Transfer Output Adjustment for Trail Edge in increments of 10%. After every incremental adjustment, run test prints and evaluate the output to determine if additional adjustment is necessary.
3. Perform an Automatic Density Uniformity Adjustment.
Note: This is a press feature and is not a PredictPrint Media Manager feature.
• Use this feature to correct image quality issues on the output when that image quality is not consistent throughout the entire output. For example, the image quality is lighter or faded or it is heavier or thicker on the left or right sides of the output, inboard or outboard.