White Balance Adjustment - LG 86UH5C Service Manual

5.2. White Balance Adjustment

5.2.1. Overview
▪ W/B adj. Objective & How-it-works
- Objective: To reduce each Panel's W/B deviation
- How-it-works: R/G/B gain in the OSD are the default value
for adjustment and differ as to color tem-
perature. Commonly G gain fix and R/B gain
upward adjustment for Cool mode, one fix
of R/G/B gain and downward adjustment for
Medium/Warm mode are applied
- Adj. condition: normal temperature
1) Surrounding Temperature: 25 ± 5 °C
2) Warm-up time: About 5 Min
3) Surrounding Humidity: 20 % ~ 80 %
4) Before White balance adjustment, Keep power on status,
don't power off
5.2.1.1. Adj. condition and cautionary items
1) Lighting condition in surrounding area surrounding lighting
should be lower 10 lux. Try to isolate adj. area into dark
surrounding.
2) Probe location: Color Analyzer (CA-210) probe should
be within 10cm perpendicular of the module surface (80°
~100°)
3) Aging time
- After Aging Start, Keep the Power ON status during 5
Minutes
- In case of LCD Back-Light on should be checked us-
ing no signal or Full-White pattern
5.2.2. Equipment
1) Color Analyzer: CA-210 (LED Module : CH 14)
2) Adj. Computer(During auto adj., RS-232C protocol is
needed)
3) Adjust Remocon
4) Video Signal Generator MSPG-925F 720p/204-
Gray(Model:217, Pattern:49)
→ Only when internal pattern is not available
5.2.3. Equipment connection MAP
Probe
RS-232C
Signal Source
※If Signage internal pattern is used, not needed
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
Color Analyzer
RS-232C
Computer
RS-232C
※
Pattern Generator
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5.2.4. Adj. Command (Protocol)
▪ RS-232C Command used during auto-adjustment.
RS-232C COMMAND
[CMD ID DATA]
wb 00 00 Begin White Balance adj.
wb 00 10 Gain adj.(internal white pattern)
wb 00 1f Gain adj. completed
wb 00 20 Offset adj.(internal white pattern)
wb 00 2f Offset adj. completed
End White Balance adj.
wb 00 ff
(internal pattern disappears )
Ex) wb 00 00 -> Begin white balance auto-adj.
wb 00 10 -> Gain adj.
ja 00 ff -> Adj. data
jb 00 c0
...
...
wb 00 1f → Gain adj. completed
*(wb 00 20(Start), wb 00 2f(end)) → Off-set adj.
wb 00 ff → End white balance auto-adj.
▪ Adj. Map
Command
Adj. item
(lower caseASCII)
CMD1
R Gain j g
G Gain j h
B Gain j i
Cool
R Cut
G Cut
B Cut
R Gain j a
G Gain j b
B Gain j c
Medium
R Cut
G Cut
B Cut
R Gain j d
G Gain j e
B Gain j f
Warm
R Cut
G Cut
B Cut
Explantion
Data Range Default
(Hex.) (Decimal)
CMD2 MIN MAX
00 C0 TBD
00 C0 TBD
00 C0 TBD
TBD
TBD
TBD
00 C0 TBD
00 C0 TBD
00 C0 TBD
TBD
TBD
TBD
00 C0 TBD
00 C0 TBD
00 C0 TBD
TBD
TBD
TBD
LGE Internal Use Only