Sharp LC-13B6US, Service Manual

Page: 17 / 104

17
LC-13B6U-S
LC-15B6U-S
5. Adjustment of white balance
1. How to adjust the white balance
1
Select the component -480i input.
2
Adjust "R CUTOFF2" and "B CUTOFF2" so that "White 30%" takes on the following WB target values.
Caution: "G CUTOFF2" should be fixed.
3
Adjust two strong colors of "R/G/B-GAIN" downward so that "White 80%" takes on the WB target values.
Caution: Any one of "R/G/B-GAIN" should be fixed at 64.
4
Repeat steps
2
and
3
so that "White 30%" and "White 80%" takes on the target values.
5
Enter the values of "R/B_CUTOFF2" and "R/G/B-GAIN" set in steps
2
to
4
in the corresponding items of
"Composite adjustment", "Component -1080i adjustment" and "PC-VGA adjustment" shown below.
6
Select the composite input and check that "White 30%" and "White 80%" are within the inspection specifications
on the next page.
Caution: The component Ys output signal of the automatic regulator should be used also when the composite
input is selected. In the case of the CVBS output, the signal level is different.
7
If "White 30%" and "White 80%" are not within the inspection specifications, make the adjustment described in
steps
2
to
4
.
8
Select the component -1080i input and check that "White 30%" and "White 80%" are within the inspection
specifications on the next page.
9
If "White 30%" and "White 80%" are not within the inspection specifications, make the adjustment described in
steps
2
to
4
.
0
Select the PC-VGA input and check that "White 30%" and "White 80%" are within the inspection specifications
on the next page.
q
If "White 30%" and "White 80%" are not within the inspection specifications, make the adjustment described in
steps
2
to
4
.
2. Adjustment value
•
Composite adjustment...RGB CUTOFF2 and RGB-GAIN on page 3 of adjustment process menu
•
Component -480i adjustment...A RGB CUTOFF2 and A RGB-GAIN on page 4 of adjustment process menu
•
Component -1080i adjustment...D RGB CUTOFF2 and D RGB-GAIN on page 5 of adjustment process menu
3. WB target value (numeric values for MINOLTA CA-210)
Adjustment value Adjustment specifications
White 80% x=0.291 ±0.006
y=0.300 ±0.006
White 30% x=0.276 ±0.006
y=0.282 ±0.006
Remarks The numeric values shown above are for MINOLTA CA-210.
(Reference) White 80%...luminance: 250 cd/m
2
, About 8500K
White 30%...luminance: 25 cd/m
2
, About 11000K
4. WB adjustment range
R/G/B CUTOFF2: –20 to +20 (G CUTOFF2 fixed at 0)
R/G/B GAIN: 36 to 64 (One of the colors fixed at 64)