Zenith M52W56LCD Service Manual page 14

7. Adjustment of White Balance and Gamma
7-1. Required Test Equipment
(1) Illuminometer (name of model : CA-100) 1EA —> Measure
color of projecting screen center
[ CA-110(name of model) is possible to measure White
Balance and Gamma —- leave it 20Cm from screen center
Follow a measurement machine manual to set CA-100 and
CA-110 measurement machine.
(2) Pattern Generator 1EA —> 16 step Gray Pattern, 64 step
Gray Pattern
(3) Set Fixation Stand 1EA
(4) Remote Control 1EA
(5) Circuit thing Jig for adjustment(Except Drive Board Assy of
adjustment model)
--- Programmed Digital Board so that the VDP Test Pattern can
output white signal by 1 level form 0 to 255 level.
7-2. Equipment Composition
Adjust to the same condition of equipment composition diagram.
7-3. Preparation for Adjustments
Compose the equipment follow Fig. 2 and place the set on the
fixation stand.
(1) Select the VDP Test Pattern signal to R1, G1, B1.
(2) Press the Instart key to select 1. LCD --> 2. 62352 and then
select 5. RVREF, 8. GVREF, 12. BVREF in adjust mode.
(3) Adjust the luminance of CA100 below 0.75Cd. (The adjust-
ment range is 196~202)
(4) Exit adjustment mode by pressing ENTER button on Remote
Control.
(5) Select 3. 7050 RGB Set in adjustment mode.
(6) Check the data 1. RContrast, 8. GContrast, 15. BContrast is
515. Otherwise set the data 515 by using volume button.
7-4. Adjustment Sequence
(1) Output the 255,255,255 signal of VDP Test Pattern, then dis-
play the maximum white pattern on screen.
(2) Gamma Adjust Mode is displayed as below when select 4.
Gamma adjust by selecting ADJ key on R/C.
Gamma Adjust Mode
1 80 100 100
2 234 216 216
3 453 411 387
16 724 740 780
RGB 456 Step123
(3) Change the 16 Step RGB Data to select white balance
x=283, y=297(D9300K).
(4) Measure the luminance with changed data.
(5) Set the every Gamma data of 16 step to 2.2 on the basis of
measured luminance data in 3).
(Max luminance *(n1/16)**2.2) — Max luminance : measured
luminance data n1 = every step unit when separating signal
level to 16 step)
ADJUSTMENT INSTRUCTIONS
* 1st Column : 16 Step Level
* 2nd Column : R Adjustment
Data
* 3rd Column : G Adjustment
Data
* 4th Column : B Adjustment
Data
(6) Output the 240, 240, 240(15th data in max white output signal
level) in the VDP Test Pattern, change the 15th RGB Data
value to come out white balance x=283, y=297(D9300K) and
measured step luminance in 5).
(7) Output the 224, 224, 224(14th data in max white output signal
level) in the VDP Test Pattern, change the 14th RGB Data
value to come out white balance x=283, y=297(D9300K) and
measured step luminance in 5).
(8) As shown above, output the VDP Test Pattern sig-
nal(208/192/176/160/144/128/112/96/80/64/48/32/16) and
change the RGB Data value of each step to come out white
balance x=283, y=297(D9300K) and measured luminance in
3).
7-5. Gamma adjustment manually
This is adjustment(after finish the 3-4) to check whether
Gamma/White Balance adjustment are well adjusted and make
correction manually.
(1) Prepare the PC Pattern Generator which is possible to output
R/G/B of 16 step and 64 step Gray Pattern.
(2) Equipment composition : Follow Fig. 2.
(3) Turn on the Jig for adjustment.
(4) Select the RGB_PC by pressing the input select button on
Remote Control.
(5) Output the 16 Gray Pattern in PC Pattern Generator.
Check it with the naked eye whether Screen Gamma and W/B
is right about each Gray.
If it's not, press the ADJ button on Remote Control and then
adjust the level data of each step manually in sub menu of 4.
Gamma Manual adjust.
(6) Output the 64 Gray Pattern in PC Pattern Generator.
Check it with the naked eye whether Screen Gamma and W/B
is right about each Gray or whether there is Gamma noise.
If there's any problem, adjust in 5).
(7) After finishing adjustment, exit adjustment mode by using
ADJ button on Remote Control.
8. White Uniformity Adjustment
8-1. Required Test Equipment
(1) Uniformity measurement equipment : Equipment which can
measure chromaticity in the whole screen
(2) Set Stand 1EA
(3) Service Remote Control
(4) Circuit thing Jig for Adjustment(Except Driver Board Assy of
adjustment model)
--- Programmed Digital Board so that the VDP Test Pattern can
output white signal by 1 level form 0 to 255 level.
8-2. Equipment Composition
Compose the equipment follow Fig. 2 and place the set on the
fixation stand.
8-3. Preparation for Adjustment
(1) Composite the equipment as shown Fig 2, and place the set
on fixation stand.
(2) After inputting company channel 13, adjust color uniformity
like Horizontal/Vertical position adjustment of input signal part
adjustment by using Service Remote Control.
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