Philips SH4 HP L1740 Service Manual page 77

Note :
1. Screen displays perfect picture at 15 factory preset modes.
2. Screen displays visible picture when input modes are other then 15 preset modes
4.3 Average Surface Brightness
Use OSD to set 6500K or sRGB color temperature in 1280x1024/60Hz
mode, measured by at screen center (position 5) with white pattern as Fig-1
Color Temperature
6500K
sRGB
4.4 Brightness uniformity
In 1280x1024/60Hz mode, set contrast at 100% and turn the brightness to get
average above 200 nits with white pattern.
The Brightness Variation shall be measured at the 9 center points by HP spec(at 10%, 50%, and 90%) called
out in the Measurement Locations Figure 2 below. If Light Leakage is visible, the Maximum Dark Luminance
shall be measured at all 11 points (9-points plus 4-points at the center of each edge).
é Maximum
æ
ç
ê
Minimum
è
ë
4.5 Check Cross talk
Cross talk of one area of the screen by another shall be measured by comparing the brightness (Y A ) of a
10 mm +/- 1 mm diameter area, with all display pixels set to the 32nd (of 0 to 63) gray level, to the
brightness (Y B ) of that same area when any adjacent area is driven dark as fig 6. The luminance
ratio shall not exceed 1:2.0
Cross Modulation Ratio =
4.6 White color adjustment
2004-10-01
Alger Huang
Brightness control
100%
NA
Luminance ù
ö
- 1 x
÷
ú
Luminance
ø
û
Y - Y
B A
<=2.0 (Max)
Y
B
32
2004-10-01
Contrast control Light output unit: nits
100% >= 200
NA >=140
%
100
<= 30%
8639 000 15861
590
19
HP L1740 77
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