Final Adjustment Of Lighting System; Lighting System Margin Inspection; Focus Test Method And Subject - LG PF1500 Service Manual

4.3. Final Adjustment of Lighting System

Check again whether the left light margin is at the edge of the
screen and if there are any dark areas on the right edge of the
screen.
Check for foreign objects, the focus line width (measuring
items : see the figures below) and the focus stopper position,
and then fix the lighting adjustment lens.
Use a UV hardening device for about 25 seconds to harden
the area where UV glue was applied. (See Fig. 4-3-1.)
Apply 0.1 g of Super X glue to adjustment screws (A) and (B),
and then let them dry completely before the final adjustment.
Make sure that the applied glue does not protrude above the
side rib, and if necessary, apply the glue to the bottoms of the
adjustment screws as well.
(Fig. 4-3-1) UV Glue Application Areas and Height

4.4. Lighting System Margin Inspection

Method and Spec.
- Apply for the sample that the decision for good/fail is difficult
during visual inspection of lighting margin.
(1) Prepare CL-200 with measurement surface of width
20mm, length 5mm as in (Fig. 4-4-1)
(Fig. 4-4-1) CL-200 for lighting margin inspection (right side)
(2) Bring up Full White pattern and check whether Light Cyan
shows.
(Fig. 4-4-2) CL-200 for lighting margin inspection (right side)
(3) Measure the brightness at the boundary of the screen.
(Refer to Fig. 4-4-3)
(Fig. 4-4-3) Measure brightness of screen boundary
(4) Measure brightness at 10mm in the inner direction from
screen boundary. (Refer to Fig. 4-4-4)
(Fig. 4-4-4) Measure brightness at 10mm inside the screen
(5) Lighting Margin Spec shall be smaller than 105% of (4)
brightness/(3)brightness.

4.5. Focus test method and subject

- Test pattern : White Cross-Hatch Pattern
- Tools : Focus width measurement ruler
4.5.1. Focus adjustment method
(1) Set the projection distance of Engine as 1837 mm (60 Inch
screen).
(2) Pop up the Resolution Pattern among the Test Patterns of
Set, and fix the Focus on the part where the White
Cross-Hatch Pattern is classified on each part of screen.
(3) Popup the White Cross-Hatch Pattern and measure the
width of each Point.
(4) Focus judging standard : 5.5 mm or less (Measure line
width excluding light Flare : Refer to Fig. 4-5-1-1)
Red Line ( light Flare), Blue Line (Thick Flare)
(Fig. 4-5-1-1) Standard for deciding line width
- 7 -