Product data

WN-5220-V Module Level Service Guide
43
These defects are defined as opaque defects that are not non-operational pixels.
Scratches are usually in the laminated films on the LCD, on the input polarizer, or
on the Fresnel lenses. Scratches can also be present on the screen itself. Blemishes
are usually foreign material contamination in the laminated films. Dust and lint
usually only cause a noticeable defect when on the LCD, Fresnels, or polarizers.
d) Smudges.
A smudge is defined as an abrupt discontinuity in uniformity, visible in a white or
gray image. Generally these are fairly large yet subtle, caused by contamination on
the mirrors, fingerprints on the LCD, polarizers, or Fresnel lenses.
3. Test Conditions.
The unit under test is to be properly calibrated to a source capable of displaying a black
image, a white image, and a grey image. The screen is viewed normal to the screen at a
distance of 1.5 meters in a room with 300 to 700 Lux ambient illumination. The ambient
temperature should be 20 to 25 degree C.
4. Acceptance Criteria.
a) Bright non-operational pixels. Counted if visible through a 5% transparency filter.
A total of 12 bright non-operational pixels are allowed.
A total of 5 bright non-operational pixels are allowed if they are joined.
b) Dark non-operational pixels. Counted if visible.
A total of 10 dark non-operational pixels are allowed.
A total of 2 dark non-operational pixels are allowed if they are joined.
c) Scratches, blemishes, dust, lint. Counted if the length + width > 1 pixel and is visible at
1.5 meters.
A total of 20 defects are allowed, including all bright and dark non-operational
pixels.
d) Screen scratches. Counted if visible at 1.5 meters.
No noticeable screen scratches allowed.
e) Smudges. Counted if visible at 1.5 meters.
No noticeable smudges allowed.