NEC LCD1550X-BK, Service Manual

Page: 70 / 209

2-15
2.8.2.2 Confirming color coordination
(1) Input timing No. 14 (60kHz/75Hz, XGA75) with signal generator, and set the pattern to full white.
(2) Set BRIGHTNESS to MAX (220) and CONTRAST to CENTER (128) with OSM, and confirm that the color
coordination at the center of the liquid crystal panel is as follows with COLOR COMPENSATION is off
(NATIVE).
x = 0.305 +/- 0.03 y = 0.324 +/- 0.03
(3) Confirm that the value of x and y at the center of the liquid crystal panel is within the values specified below
with BRIGHTNESS is set to MAX (220) and CONTRAST to CENTER (128) when each COLOR is selected
with COLOR SELECTION (AccuColor).
If out of specification, compensate with each color temperature.
Color1 9300
j
: =0.281 +/- 0.015 =0.290 +/- 0.015
Color2 8200
j
: =0.290 +/- 0.015 =0.300 +/- 0.015
Color3 7500
j
: =0.300 +/- 0.015 =0.310 +/- 0.015
SRGB 6500
j
: =0.313 +/- 0.010 =0.329 +/- 0.010
Color5 5000
j
: =0.345 +/- 0.015 =0.352 +/- 0.015
2.8.2.3 Panel inspection (luminance / color coordination / defect)
(1) Luminance and color coordination
Input the confirmation timing with signal generator, and set the picture pattern to full white (0.7Vp-p).
Measure
the luminance and color coordination with a luminance meter, and confirm that the values are as shown
below.
For measuring of optical parameters, carry out the measurement where there is little effect from outer light (in
a dark room, etc.), and the panel should be heated run for 30 minutes or more.
Mode Definition
Color
setting
Contrast Bright Criterion
Contrast
ratio Full white/Full black
luminance at point A NATIVE CENTER MAX 150 or more (*)
White
luminance Full white luminance
at point A NATIVE CENTER MAX 175cd/m
2
or more
300cd/m
2
or less
MAX 175cd/m
2
or more BRIGHT
variable
range Luminance at point A
MAX value and MIN
value NATIVE CENTER
MIN 15cd/m
2
to 30% of BRIGHT MAX value
(For judgement, 1 minute or more should be
passed after BRIGHT was changed.)
Xw Color coordination at
point A (X value) NATIVE CENTER MAX 0.305 +/- 0.03 or less
Yw Color coordination at
point A (Y value) NATIVE CENTER MAX 0.324 +/- 0.03 or less
* The criterion of 1cd/m
2
or less are executed by the blink of the measurement value (the measurement
value is regarded as reference).