LG 42LG50 Service Manual page 8

Peak & average Brightness & Contrast measure standard specification
- White Peak brightness measure specification
1) In non-impressed condition, measure peak brightness displayable as much as possible LCD module.
2) Measuring instrument: CA-110 or a sort of Color Analyzer.
3) Pattern Generator : VG-828 or a sort of digital pattern generator (displayable Full White & 1/25 White Window pattern)
4) Measure condition
- Test pattern: in center, 1/5(H)x1/5(V) of Window Pattern (white pattern in non-impressed condition)
- SET condition : Contrast & Brightness Level 100%
- Environment condition : Dark room in the non outside light
- Video menu option condition
RF
AV
Component
RGB
HDMI
5) Measurement
- Do heat-run LCD module at 30minutes in normal temperature (25°C) by using full white pattern of 15% signal level(38 gray
level).
- Impress test pattern signal in 1/5(H)x1/5(V) White Window of 100%(255Gray Level)
- measure 3 times brightness of central white window, and mark peak brightness in max brightness degree
- measure the same condition in video signal /RGB signal.
Average Brightness measure specification
1) Impress 100%(255Gray Level) full white pattern at the same peak brightness measurement.
2) Measure average brightness in 9 points.
1 4
2 5
3 6
Contrast ratio measure specification
1) Test display signal : 30x30 dots White Window signal & all Black Raster signal
2) Dark room measure condition : Using touch type Color analyzer CA-100 Dark room in the non outside light
3) Bright room measure condition : In bright room of 150Lx illumination in the panel surface, locate a source of light on the above
45°of the panel surface.
4) Measure method
- In standard test condition, impress 30x30 dots White Window Pattern signal .
Measure center peak brightness degree Lw of white window
- Impress black Raster signal as contrast ratio measurement signal.
Measure black brightness degree Lb of PDP central
Calculate the following numerical formula.
Contrast ratio = Lw / Lb
* If it does not use Prior measurement, use generally simple test measurement.
The Correct measure specification is followed by IEC61988-2/CD, JAPAN EIAJ-2710
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Only for training and service purposes
Signal Picture Mode
NTSC-M USER1
NTSC-M USER1
720P USER1
1024x768 USER1
DTV 720P USER1
7
8
9
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XD Black Level
Off N/A
Off Low
Off N/A
N/A N/A
Off High
LGE Internal Use Only