Acer AT2245, Service Manual

Page: 43 / 75

43
White-Balance, Luminance Adjustment
Approximately 30 minutes should be allowed for warm up before proceeding white
balance adjustment.
First adjust PC mode and then adjust AV mode, before started adjust white balance, please setting the
Chroma-7120 MEM. Channel 1 to Cold color, MEM. MEM. channel 3 to standard color, MEM. and MEM.
channel 5 to warm color, ( our cold parameter is x = 300 ± 15, y = 310 ± 15, Y = 350 ± 7 cd/m2 ; ;standard
parameter is x =314 ± 15, y =324 ± 15, Y = 350± 7 cd/m
2
;warm parameter is x =326± 15, y = 335± 15, Y = 350± 7
cd/m2),
Color Temp. Cold(7500K) Standard(6500K) Warm(5000K)
x 300 314 326
y 310 324
335 PC MODE
Y 350 350 350
x 300 314 326
y 310 324
335 AV MODE
Y 420 420 420
How to setting MEM. channel you can reference to Chroma-7120 user guide or simple use “ SC ” key and “ NEXT ”
key to modify x, y , Y value and use “ ID ” key to modify the TEXT description
Following is the procedure to do white-balance adjust
Notes: Step of AV mode adjustment is the same as PC mode,
PC mode:
I. Press menu key, then press code 2
Æ
3
Æ
4will into the factory mode, the OSD will show menu
and a word “Factory” at the top of Menu.
1. In the factory mode select “COLOR TEMP” may be select the difference color temp.
2. Select SCALER Adjustment:
RG, GG, BG Æ R, G, B Gain adjust.
RB, GB, BB Æ R, G, B Bias adjust.
<Notes: the R, G, B gain use 9 bits, and R, G, B bias use 10 bits to save the value in EEPROM, so if the
R, G, B gain and bias is 255 to 256, the “P0 256” will change to “P10”>
II. Bias (Low luminance) adjustment:
1. Set the raster pattern (Black pattern with 1024 × 768) Input.
2. Set the contrast on OSD window to the value=80, Brightness set to “80”
3. Adjust the brightness on OSD until chroma 7120 measurement reach the lowest value.
III, Gain adjustment:
A. Adjust Cold color-temperature:
Chapter 7