Philips 190VW8FB/93 Service Manual page 68

190VW8 LCD
68
8.10 White Uniformity
Definition of White Variation (δW):
Measure the luminance of gray level 255 at 9 points
δW = Maximum [L(1), L(2) ...... L(9)] / Minimum [L(1), L(2) ...... L(9)]
90%
1
4
7
8.11 Contrast ratio
The contrast ration can be calculated by following expression.
Contrast Ratio (CR) = L255 / L0
L255 : Luminance of gray level 255
L0 : Luminance of gray level 0
Typical value:
8.12 White color adjustment
There are six factory preset white color 11500K, 9300K, 8200K, 7500K, 6500K, sRGB, 5000K
Apply full gray64 pattern, with brightness in 100 % position and the contrast control at 50 % position.
The 1931 CIE Chromaticity (color triangle) diagram (x , y) coordinate for the screen center should be:
Product specification
CIE coordinates
11500K
9300K
8200K
7500K
6500K/sRGB
50%
2
5
8
Spec : =< 1.33 (In all ranges)
1000:1
(x,y)
x = 0.270 ± 0.02
y = 0.281 ± 0.02
x = 0.283 ± 0.02
y = 0.297 ± 0.02
x = 0.291 ± 0.02
y = 0.306 ± 0.02
x = 0.298 ± 0.02
y = 0.314 ± 0.02
x = 0.313 ± 0.02
10%
10%
3
6 50%
9 90%