Product

• Lotem^® 800 II Family
• Lotem Quantum
• Lotem Quantum Spectrum
• Lotem 400 Quantum

Procedure

The following procedure describes how to perform rotational geometric corrections for both big and small plates.

Plates with a subscan size <= gc MaxSmall parameter use RotationSmall.
Plates with a subscan size > gc MaxSmall parameter use Rotation.

1. To calculate the rotation (or the parallel image alignment), photograph a grid onto a large plate that touches the external registration pin, for example 770 x 1030 x 0.30.
2. Use a microscope to measure the deviation value.

3. Enter the approximate deviation values in microns. There is no need for exact precision because the alpha angle (measured in Radians), is extremely small.
   • If HP is less than EP, enter a negative (-) value.
   • If HP is more than EP, enter a positive (+) value.
   • Update the results: Quantum>Set gc rotation X

Note: Do not enter corrective values if they are greater than 200 microns. Deviations greater than 200 microns must be corrected with an alignment device.

4. Make a parallel image alignment onto a small plate that touches the GTO registration pins, for example 381 x 457 x 0.30. This action should be performed in exactly the same manner as that in step 1.
5. Enter the results: Quantum>set gc rotationsmall X, where X is the deviation value. The rotationsmall parameter is used for plates that have a screw axis of less than 605, whereas MaxSmall is used for plates that have a screw axis of greater than 605.
6. Upon completing the direction tests, load a plate measuring 770 x 103 x 0.30. Make sure the plate does not touch GTO plate's registration pins.

Technical contact(s)

Nir Peleg

Date submitted

14 Aug 2003