Sharp 2T-C45AE1X, Service Manual

Page: 10 / 44

2T-C45AE1X
5 – 3
4.
WHITE BALANCE ADJUSTMENT/ GAMMA ADJUSTMENT
.
White Balance Adjustment / Gamma Adjustment
NO.
ITEM CONDITION PROCEDURE
a)
Setting
AV Mode : DYNAMIC
Backlight : MAX
Set the luminance
meter on the centre
of the screen
For the details of white balance adjustment procedure, please refer to white balance
adjustment spec for Kameyama model.
1. Confirm the set condition.
2. Connect the white balance jig.
i. 3.5mm H/P Jack. ( 4 Pole Pin)
ii. RS-232 Cross cable ( 2 pcs ) + Convert wire from RS-232 D-Sub ( 9 pin to 3.5mm
H/P Jack ( 4 Pole Pin ).
3. Through RS-232C command, adjustment mode screen is displayed.
b) Auto
Adjustment
[command]
Adjustment
Mode
KRSW0001
KKT10037
Setting
KYOF0001
OSDS0001
SBSL0016
Multi point
adj. Mode
MSET0000
WBI20255
Adj Point 2
WBI20 229
MG2G****
MG2B****
MG2R****
Adj Point 1
WBI100 40
MG1G****
MG1B****
MG1R****
Write
MSET0003
Initial setting
Panel Contrast
R/G/B_MAX
R/G/B_HIGH
R/G/B_LOW
C
nt
= 4800 :1
WB
MAX
= 4080
WB
H = 3664 /4080
WB
L = 640 /4080
(1) Measurement MAX Brightness
(2) Set MIN Brightness
(3) Measurement HIGH Brightness
(4) Measurement LOW Brightness
(5) Calculation H
γ
(6) Calculation L
γ
(7) Calculation HIGH luminance ( γ=2.2)
(8) Calculation Initial setting of
R/G/B_HIGH
(9) Set Initial setting of
R/G/B_HIGH
(10) Original WB adjustment is performed (HIGH)
Set the specified gradation for point 2, fix the
most faint colour to get reference value,
adjust others 2 colours to minus adjustment
for reference value of point 2.
(11) Measurement HIGH Brightness
(Set) R_HIGH= G_HIGH
G_HIGH= G_HIGH
B_HIGH= G_HIGH
(12) Calculation MAX luminance after WB
ADJ set to γ=2.2 (L XHG
)
(13) Set R/G/B_MAX
(14) Calculation LOW luminance (
γ=2.2)
(15) Calculation Initial setting of
R/G/B_LOW
(16) Set Initial setting of R/G/B_LOW
L
max
=305.7 cd/m²
L min = L max /C nt = 0.102
L
XH
=235.1 cd/m²
L
XL
=2.06 cd/m²
H
γ
=LOG((L
XH
-L
min
)/(L
max
-L
min
))/LOG(WB
H
/WB
MAX
)= 2.44
L
γ
=LOG((L
XL
-L
min
) /(L
max
-L
min
))/LOG(WB
L
/WB
MAX
)=2.73
L
H22
=(L
max
-L
min
) x (WB
H
/WB
MAX
)^2.2+L
min
=241.31
WB
HX
=WB
MAX
X ((L
H22
-L
min
)/(L
max
-L
min
))^(1/H γ )=3703
R_HIGH=WB
HX
ʼ=3703
G_HIGH=WB
HX
ʼ=3703
B_HIGH=WB
HX
ʼ=3703
R_HIGH=3702
G_HIGH=3641
B_HIGH=3703
R_HIGH=3641
G_HIGH=3641
L
XHG
=
231.3
B_HIGH=3641
L
XMX
=L
XHG
/((W B
H
/WB
MAX
)^2.2)=293.04
R_MAX=G_MAX*(R_HIGH/G_HIGH)=4078
G_MAX=WB
MAX
X ((L
XMX
-L min )/(L max -L min ))^(1/H
γ
)=4010
B_MAX=G_MAX*(B_HIGH/G_HIGH)=4078
L
XLX
=(L
XMX
-L
min
) x (WB
L
/WB
MAX
)^2.2+L
min
=5.08
WB
LX
=WB
MAX
X ((L
XLX
-L
min
)/(L
max
-L
min
))^(1/L γ )=901
R_LOW=WB
XLX
=901
G_LOW=WB
XLX
=901
B_LOW=WB
XLX
=901
Example for adjustment method
(be careful of INT setting)
RESULT
RESULT