Imaging Process Adjustment; Gradation Adjust - Konica Minolta bizhub C250 Service Manual

10. Service Mode

10.6 Imaging Process Adjustment

10.6.1

Gradation Adjust

• It will not be displayed when the following setting is set to "ON".
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[Service Mode]
Functions • To make an automatic adjustment of gradation based on the test pattern produced
and the readings taken by the Scanner
Use • Color reproduction performance becomes poor.
• The IU has been replaced.
• The Image Transfer Belt Unit has been replaced.
✽ The Adj. Values of Dark. and Highlight shown on the Gradation Adjust screen repre-
sent how much corrections are made to produce an ideal image output. Conv. Value
shows the difference from the ideal image density.
✽ The closer the Conv. Value to 0, the more ideal the image.
• Gradation Mode
• Resolution Mode
• High Compression Mode : It gives the highest priority to increasing the number of
Adjustment Dark
Specification Highlight : 0 ± 60
Setting/ NOTE
1
• Before conducting the Gradation Adjustment, make sure to turn Main power
Procedure
OFF to stabilize the image. Wait for more than ten seconds and turn power
back ON.
1. Touch [Gradation Adjust].
2. Select the appropriate mode for the gradation adjustment.
3. Press the Start key to let the machine produce a test pattern.
4. Place the test pattern produced on the Original Glass.
5. Place ten blank sheets of A3 paper on the test pattern and lower the Original Cover.
6. Press the Start key. (The machine will then start scanning the test pattern.)
7. Touch [OK] and repeat steps from 2 through 6 twice (a total of three times).
8. Touch [Gradation Adjust] to display the Adj. Values and Conv. Values of each color
(C, M, Y and K) for Dark and Highlight.
9. Use the following procedures to check the Conv. Value.
Dark: 0 ± 100 and Highlight: 0 ± 60: It completes the adjustment procedure.
If neither Dark nor Highlight falls outside the ranges specified above: Perform
steps from 2 to 6.
NOTE
1
• If the convergence falls within the specified range after the second Gradation
Adjustment, further adjustment may not be necessary.
• If a fault is detected, "0" is displayed for all values. In that case, after turning off the
Main Power Switch, turn it on again more than 10 seconds after and then make the
Gradation Adjustment again.
• If either Max or Highlight still remains outside the specified ranges perform D Max
Density.
• If a total of four sequences of Gradation Adjust do not bring the values into the spec-
ified range, check the image.
• If the image is faulty, perform the troubleshooting procedures for image problems.
310
[Image Process Adjustment]
: It gives the highest priority to gradation performance of
the image as it adjusts.
: It gives the highest priority to reproduction performance
of letters and lines as it adjusts.
images to be stored in the memory as it adjusts.
: 0 ± 100
Field Service Ver. 3.0 Aug. 2006
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[Dev. Bias Choice]