Faulty Color Reproduction; When Copying, Gray Part Of Color Original Takes On Red Tinge; Density Difference Occurs (With Gray Characters) Between Duplex Copy And Booklet Copy Generated In Acs (Auto Color Selection) Mode; At Send Transmission, Color Original Is Scanned As Monochrome Color Original: Description On Method For Adjusting Color Recognition Level In Acs Judgment - Canon Color iR C3480 Service Manual

Chapter 15

15.3.1.9 Faulty Color Reproduction

15.3.1.9.1 When copying, gray part of color original takes on red tinge

Color iR C3380G / Color iR C2880G / Color iR C3380i / Color iR C3380 / Color iR C2880i / Color iR C2880 / iR C3480 / iR C3480i / iR C3080i / iR C2550
[ Inspected by Canon Inc. ]
Description
Since gray part of a color original sometimes took on a red tinge at copying, an adjustment was performed in service mode.
Example: In this inspection case, the gray zones in the 4 directions of CA-1 chart slightly went red.
Note: There is no need to perform the adjustment below unless the customer is complaining about this symptom.
Field Remedy
1. Service mode > COPIER > Adjust > COLOR > adjust the value for [ADJ-C] between "+1" and"+4".
2. If the symptom still occurs, perform the following procedure: [Service mode > COPIER > Adjust > COLOR > adjust the value for [OFST-M] between "-
1" and "-4"].
Note: Be sure to adjust the foregoing service modes within the adjustment ranges. If they are set to a value without the adjustment ranges above, this machine
will lose the color balance.
15.3.1.9.2 Density difference occurs (with gray characters) between duplex copy and booklet copy generated in ACS (Auto Color
Selection) mode
Color iR C3380G / Color iR C2880G / Color iR C3380i / Color iR C3380 / Color iR C2880i / Color iR C2880 / iR C3480 / iR C3480i / iR C3080i / iR C2550
[ Inspected by Canon Inc. ]
Description
When making a duplex copy and a booklet copy in ACS mode, there is a difference in density of gray characters between these copies. (The density of the
booklet copy becomes lighter, however, this symptom does not occur in full color or black-and-white mode.)
Field Remedy
Check the version of system software; If SYSTEM, LANGUAGE, and RUI are earlier than Ver.21.11 and Ver. 21.05, upgrade these pieces of software to
Ver. 21.11 and Ver. 21.05 or later.
15.3.1.9.3 At SEND transmission, color original is scanned as monochrome color original: Description on method for adjusting color
recognition level in ACS judgment
Color iR C3380G / Color iR C2880G / Color iR C3380i / Color iR C3380 / Color iR C2880i / Color iR C2880 / iR C3480 / iR C3480i / iR C3080 / iR C3080i / iR
C2550
[ Case in the field ]
Description
Since color originals were scanned as monochrome color originals at time of SEND transmission, the setting values for ACS-EN2 and ACS-CNT2 were
increased in service mode for solution.
Field Remedy
1. In service mode (level 2) > COPIER > Adjust > MISC > ACS-EN2, increase the setting value.
- ACS-EN2: used to adjust the ACS judgment area for the stream reading. If the setting value is increased, then the judgment area is expanded. The adjustable
range is '-2' to '2.'
2. In service mode (level 2) > COPIER > Adjust > MISC > ACS-CNT2, increase the setting value.
- ACS-CNT2: used to adjust the color judgment pixel count area in ACS judgment at time of the stream reading. If the setting value is increased, then the
area is expanded. The adjustable range is '-2' to '2.'

15.3.1.10 Stretching/Shrinking

15.3.1.10.1 How to correct distorted image (faulty squareness)

Color iR C3380G / Color iR C2880G / Color iR C3380i / Color iR C3380 / Color iR C2880i / Color iR C2880 / iR C3480 / iR C3480i / iR C3080i / iR C2550
[ Verified by Canon Inc. ]
Description
Since output images had problems in geometric features (squareness at the trail edge, and parallelism), the pressure of the registration roller was adjusted for
solution.
Reference: In this verification case, 2 washers (1mm in thick) were added. As a result, approx. 0.5mm improvement could be seen in the geometric features
of the blank area at the trail edge.
Field Remedy
1. Open the right door.
Note: Be sure not to forcibly push the right door in the direction of opening it.
15-22
0015-6699
0016-3765
0019-3706
0016-4950