Konica Minolta bizhub C650 Service Manual page 512

Field Service Ver. 8.0 Jun. 2008
B. LD lightness balance adjust.
Functions • This function adjusts the LD lightness balance between the two LDs to correct the dif-
ference of LD lightness between the LDs.
Use • This setting is made after the PH unit or the service EEPROM board is replaced.
• This adjustment is made to prevent uneven density in highlighted halftone area pro-
cessed with error diffusion being caused by inappropriate laser intensity.
Setting/ 1. Call the Service Mode to the screen.
Procedure 2. Touch these keys in this order:
[Machine] → [LD adjustment] → [LD lightness balance adjust.].
3. Select [For adjustment] and press Start key.
4. The test print includes seven rows of patterns produced with different levels of LD2
light intensity towards LD1.
5. Three squares each made up by four small squares are printed with the different four
colors. The two small squares diagonal to each other are printed using the same LD.
Depending on individual print timing, it is decided that which pair of small squares
corresponds to which LD.
The pair of small squares where image density changes corresponds to LD2.
6. From the test pattern, select the pattern where the least density difference appears
between LD1 and LD2 for each color.
7. Enter the adjustment value corresponding to the pattern you selected (see the above
illustration) or a value close to the adjustment value using the ten key pads on the
panel.
8. Select [For effect confirmat.] and press Start key.
9. Check that LD2 small squares have no image noise of woodgrain.
10.Touch [OK].
-9 % -6 % -3 % 0 % +3 %
10. Service Mode
+6 % +9 %
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