39 Banding on Halftone
[Symptom]
When solid part or blank part appears in the halftone area, the density of halftone becomes
darker or lighter.
Density of the halftone area at the
side of tree becomes darker.
Density of the halftone area
becomes lighter.
[Probable cause]
a) If blank area exists in the halftone area, the transfer current concentrates to the halftone
where toner is attached. Consequently, the transfer ratio increase at the halftone then
density increases.
b) If solid area exists in the halftone area, the transfer current concentrate to the solid part
where the more toner is attached. Consequently, the transfer ratio decreases at the
halftone area and density decreases.
[Solution]
By reducing the 1
st
transfer current, the current concentration degree can be reduced and the
difference of the density is improved.
[Utility Counter] =>[03 Machine Admin. Setting] => [01System Setting] => [05 Expert
Adjustment] => [06 Process Adjustment] => [01 Front & Back Density]
Reduce the 1
st
transfer current from yellow to black by step by step (decrement by 1 step) and
find the best condition.
The banding cannot be eliminated completely but can be improved.
CAUTION: If the 1
st
transfer current is decreased too much by [01 Front & Back Density]
adjustment, the white spot may appear. Please mind it and check the image carefully
when performing the adjustment.
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