Xerox Phaser 8860 Service Manual page 297

Automatic calibration uses built in targets. The target for the flatbed is on the back of the
diverter strip; the target for the DADF is located on the back of a moveable flap, internal to the
DADF. The calibration is automatic at power-up, when coming out of energy star mode, and at
a predetermined schedule based on the length of time the lamps have been on continuously.
Automatic DADF Calibration
Calibration for the DADF is performed at initial power-up and "as required" with normal usage
of the DADF. The steps are the same for both conditions.
1. The lamps turn on.
2. The calibration strip moves back slightly from the home position, to confirm the home
position, then extends into the image path.
3. The calibration strip holds this position until the Charge Coupled Device (CCD) image
reaches a specified luminescence value and is stable.This time varies depending on the
starting conditions of the lamp.
4. Once the color stabilizes, the strip retracts back to its home position.
Figure 2 DADF Calibration Strip
Automatic Scanner Calibration
1. Lamps turn on.
2. The scanhead drives toward the automatic calibration target to ensure that the head lock
is released.
3. Scanhead moves back to the home position flag, out, and back in to confirm operation.
4. Scanhead moves under the calibration target until the CCD achieves a predetermined
image quality and stability.
Initial Issue
Phaser 8860/8860MFP Service Manual
5. Scanhead moves toward platen glass to confirm motion control.
6. Scanhead moves back to the home position under the CVT window.
Manual Calibration
Manual calibration is a maintenance procedure accessed through the Control Panel. Scanner
calibration requires the calibration sheet provided with a replacement Scanner Assembly. It is
designed to ensure the DADF and scan heads are aligned to the system (motion control), the
scan heads are aligned to one another (duplex scanning alignment), and that certain white,
black and gray scale calibrations are performed. This calibration is performed:
• At the factory during initial system setup.
• Whenever the document feeder or scanner assembly, or both, are replaced.
• If troubleshooting determines that the calibration has drifted or that the calibration data
has been erased from the system (ESD event).
NOTE: The manual calibration procedure is detailed in
09/2007
8-5
ADJ 1.15.1.
Theory of Operation
Image Input Terminal