Product

• Kodak^® ThermoFlex^® Mid
• ThermoFlex Narrow

Background

The objective of the laser uniformity test is to verify that the laser beams are working properly, and are not significantly different from each other in their visual results.

Each laser beam must produce a clean screen that is free of jitters, unexpected patterns, and differences in dot shape.

Requirements

• Densitometer
• Microscope
• Flexo plate(s)
• Offset plate(s) if the configuration includes offset option
• Nozzle adjusted
• Anti-collision system adjusted
• Focus tested and adjusted, as described in the Focus Calibration Test
• Elevation tested and adjusted, as described in the Elevation Calibration Test
• Resolution value obtained in the Resolution Calibration Test
• Delay value obtained in the Delay Calibration Test
• Drum speed obtained in the Drum speed calibration test (for flexo plates)
• Intensity obtained in the Intensity Calibration Test (for offset plates)

Procedure

1. Verify the following:
   • All the laser ddb factors are set to 0.
   • In the registry, under EXPOSE, the Laser Calibration From Host Enable parameter is set to 0.
     
   Note: For this test you must activate all available diodes in the laser box.
2. Load a plate.
3. In TIFF FE, from the Launch Pad, select Utilities > Calibrate.
   
4. In the Calibration Type box, select Laser Uniformity.
   
   
5. In the Current Plate list, select the plate that you are using.
6. In the Drum Speed box:
   • Flexo plates: Type the value you found in the drum speed test.
   • Offset plates: Type 500.
   
   
7. In the Resolution list, select 100.
   
   
8. Define the Image offset values:
   • Horizontal offset—The value around the drum in mm
   • Vertical offset—The value along the drum in mm
   If you use the same plate for several tests, define different offset values for each test.
   Note: The (0,0) offset coordinate is located at the upper-left corner of the plate.
9. In the Test Factor Values (%): section, in the From and To boxes, type a value of 0.
10. In the Number of Steps box, type 1.
11. Click Test to expose the plate.
12. Visually check the results to see if the lasers work and produce a clean screen (no slashes, patterns, shifts, extra dark or bright solids`, etc.). If the results are not acceptable, repeat the test. If all tests produce the same results, the diode is faulty.
13. A diode that does not work may influence adjacent diodes, so first replace only the diodes that produce effects such as patterns, and the diodes that produce a much darker solid than those of the surrounding diodes (such as the two indicated on the left in the following picture).

• If all lasers work and produce a clean screen, continue with the Resolution Calibration Test procedure.
• If one or more lasers do not work or do not produce a clean screen, replace the required diode(s) and perform the procedure again.

Technical contact(s)

Content owner: Viki Arviv
See the Escalation page for escalation contacts.

Date submitted

29 Jun 2004