B_min
X
100%
B_max
Where B_max = Maximum brightness
B_min = Minimum brightness
8.10 White
Uniformity
Definition of White Variation
(δ
W):
Measure the luminance of gray level 255 at 9 points
δ
W = Maximum [L(1), L(2) …… L(9)] / Minimum [L(1), L(2) …… L(9)]
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
Min. value:
700:1(CPT)
Typical value:
1000:1(CPT)
8.12
White color adjustment
There are three factory preset white color 9300K, 6500K, sRGB.
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:
8.13
Distance between TFT LCD monitor and CRT/TFT monitor
Conducted with different modes or frequencies. No interference in a distance down to 25 cm.
70
220EW8 LCD
9
2
4
5
6
7
8
1
3
10%
50%
90%
10%
50%
90%
