AGFA CR 30-X - 5.1 Description of most important Components for Scanning; 5.2 Functions of Calibration Board

Functional Description
DD+DIS150.06E
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Chapter 2 / 8 CR30-X Edition 1, Revision 0
Agfa Company Confidential Type 5175/100
5.1 Description of most important Components for Scanning:
Laser Diode:
• Power
max
= . 45 mW
Polygon:
• 6 facets
• Ball bearings
• Run-up period approx. 5 sec.
• Follow-up period approx. 10 min.
Calibration Board
• BOL / EOL Sensor
• 16 pin diodes
5.2 Functions of Calibration Board:
• Geometric Correction:
To correct irregularities in the optical path, the digitizer measures at each
boot-up the timings of the laser beam between pin diode 1 and 2, 2 and 3 and
so on.
As a result a kind of "calibration curve" is created, which influences the
frequency of AD conversion. This corrects possible distortions.
• Jitter Correction:
To correct irregularities in the polygon run, the digitizer measures the timings
between the BOL and EOL signal during each scan. Certain irregularities,
which may be caused by external vibrations or the polygon ball bearings are
smoothed by calculating mean values of several scan lines.
• Synchronization of Polygon, Begin of Scan, Begin of Line and AD
Window:
When an IP is inserted the polygon starts up. The BOL/EOL sensors measure
the position of the polygon mirrors (they even detect each single facet)
When the IP arrives for scanning, the sensors of the calibration board detect
the IP edge and generate the begin of scan signal (BOS).
The begin of line signal (BOL) triggers a timer for switching on the laser beam
and the AD window.
The length of the AD window and "Laser On" depends on the image plate size.