NEC MultiSync FP1350 Service Manual page 111

• Low contrast: Visually noticeable stain and flaw, etc. that rarely block off the Light from the phosphor screen.
→ visible interference color through the reflection (not visible through the permeability)
(Note) Ignore the light spot with no interference color.
(However, Non of them with its size in excess of 3.75mm is acceptable, that damages
the product quality.)
Standards
Mean diameter for each contrast (Note 1) (mm)
High contrast
Smaller than 0.10 Smaller than 0.20
0.11 ~ 0.25
0.26 ~ 0.50
0.51 ~ 0.75
Values inside [ ] represent acceptable number in low contrast.
See the table in the next page for total defect number, which is acceptable in low contrast.
Total standards for low
contrast defect
Standards for each zone
Total of A + B
(Note 1) Mean diameter = Either value of (a + b) / 2, 20+2b, which is smaller. (a: length
(Note 2) Acceptable interval shall be the larger one in the case that defects have different intervals.
(Note 3) There is no standard regarding zone C. Therefore, no defect is accepted that may deteriorate the
value of products. Defect level by consultation. Discuss if necessary.
: ≤ 0.7% (at the screen center)
3-3. Reflectance
3-4. Reflective color irregularity
No reflective color irregularity is accepted, which is easy to find visually.
3-5. Strength
Wear and abrasion resistance: Coating should withstand 30-minute scrubbing with a #50 eraser. (load; 500g)
Pencil resistance: Coating should withstand 3H pencil. (according to conformed item of Coating Strength
JIS-5400)
[Supplementary explanation] Definition of striped coating (tear) and flaw (rubbed coating) (according to JIS)
Striped coating (tear): Tear that reaches to the glass surface
Flaw (rubbed coating): Scratches that slightly dig into the surface of the coating
3-6. Dirt, cloudiness, color irregularity, streaks and other defects
No defects should not be detected when white or green raster are on the screen.
Set the new boundary sample if necessary.
Middle contrast
Smaller than 0.50
0.21 ~ 0.50
0.51 ~ 1.00
1.01 ~ 1.50
A
6
Acceptable number in
each zone
Low contrast Zone A
Ignore
0.51 ~ 1.25 2 [4]
1.26 ~ 2.50 1 [4]
2.51 ~ 3.75 0 [4]
B
8
10
6-7
Acceptable
interval (mm)
Zone B
Ignore -
4 [5] 20
2 [4] 40
1 [4] 80
b: width)