Ila Back Focus; Ila® Back Focus - Hughes JVC 100 Service Manual

18. Adjust the Z-Axis to increase light output. Use either a 10mm socket or a
5mm hex wrench (see Figure 3-6).
19. When the desired light output is achieved, tighten the 4 retaining screws.
20. When proper rolloff is obtained, return the ILA
level from Step 4, and recheck the "Shutters on Hide" box.
Loosen these
screws for
Z-Axis
adjustment
(two more
screws under
the Arc Lamp
Module)
®
3.3 ILA Back Focus
®
The ILA Back Focus adjustment moves the CRT/ ILA
adjust the focal length so that the image will be focused on the screen. When using
a zoom lens this adjustment allows the zoom lens' tracking to remain focused
throughout the entire range. Use the Pluge/Grey test pattern to perform this
adjustment one color at a time. The procedures below perform the ILA
Focus for the Green lens. The first procedure is for a zoom lens. The second
procedure is for a fixed lens.
To adjust the ILA
1. Remove all the covers (seeSection 4.2).
2. View the Green Channel. Hide the Red and Blue Channels.
3. Select Test Pattern #7 (the Pluge/Grey test pattern).
4. Select Projection Lens from the menu.
5. Use the up/down arrow keys to zoom the Projection Lens to smallest
image.
6. Use left and right arrows to focus the projection lens to get sharply focused
spacer balls.
NOTE: Spacer balls are used inside the ILA
separate the layers. They are tiny, random, irregularly-shaped spots that are
Model 100 Service Manual
Figure 3-6 Arc Lamp Z-Axis adjustment.
®
Back Focus for a Zoom Lens:
Chapter 3---Service Adjustments
®
bias adjustment to the
Z-Axis
Adjustmen
t
®
assemblies together to
®
®
Assembly to
Back
3-9