NEC LCD1550X Service Manual page 74

Note 7: A set of 2 or more dot defects in an area of 5x5 pixels
If there are 2 or more dot defects ( ) in an area of 5 5 pixels, such a set of dot defects
shall be counted as one cluster.
5 5 pixels
1 cluster
Note 8: Approach of defects of
5 5 pixels
R G
There should be no approach of
There should be no approach of
*11) There should be less than 1 piece of spot on monochromatic picture and the size should be within
*12) Uneven spot should be less than
*13) Removable dusts are excluded.
*14) This standards should be applied to the display part (pixel area).
Dot defect ( )
There should be less than 2 clusters throughout the screen area.
or in an area of 5 x 5 pixels
To be counted as NG
R G
@ s or A s in an area of 5 ~5 pixels.
s or in an area of 5 5 pixels.
10mm when it is judged on 128/256 gradation.
5 5 pixels
R G
R G
2-19
1.2mm.