Blue Defocus; White Balance - Hitachi 51UWX20B Service Manual

2.8 Blue defocus adjustment
Adjustment Preparation
(1) Optical and electrical focus adjustment should
have been completed.
(2) The convergence adjustment should have been
completed.
(3) Set Video conditions to factory preset.
(4) Input the cross-hatch signal.
Adjustment procedure
(1) Turn the B Focus VR (Focus Pack) fully
clockwise.
(2) Adjust sticking out level of blue to specification
shown in table below, by turning the (B) FOCUS
VR counter clockwise.
UNEVENNESS SPECIFICATION: ±1cd/m 2
Defocus sticking out specification
Screen Size
43"
51"
57"
Condition: User controls are set to the initial set
positions (for shipment)
Measuring point-Screen center.
2.9 White balance adjustment
(1) Screen adjustment
(2) High light white balance.
(3) Low light white balance.
I 2 C data for High light white balance
Green : G DRIVE (HIGH) 3F (initial data)(Adjustable)
Red : R DRIVE (HIGH) 3F (initial data)(Adjustable)
Blue : on FOCUS PACK UFPK
I C data for Low light white balance
2
Green : G CUT OFF (HIGH) 7F (initial) (Fixed data)
Red : R CUT OFF (HIGH) 7F (initial) (Adj. data)
Blue : B CUT OFF (HIGH) 7F (initial) (Adj. data)
Adjustment Preparation
(1) Adjustment should start 20 min. or more after the TV
power is turned ON.
(2) CUT OFF ADJ. should be finished.
(3) VIDEO control : Contrast is MAX., Others are center.
(4) Color temp. : HIGH
BACK TO ADJUSTMENTS
STICKING OUT OF BLUE
Blue sticking out
1.0mm
1.0mm
1.0mm
(5) Signal:
* Hight Light white Balance Adj.
White raster 0.715Vpp (w/o sync., termination
incidence : 75ohm.) 100IRE
* Low Light white balance ADJ.
White raster 0.180Vpp (w/o sync., termination
incidence : 75ohm.) 25 IRE (The brightness
equal to 20cd/m
model)
(6) BLUE defocus ADJ. should be finished.
(7) The vertical incident illumination on the screen
should be 20 Lux. or less.
(8) Picture Format is 16:9 Standard Mode.
(9) Sub Brightness adjustment should be finished.
(10 )Go into I C service mode.
2
Table 1: White Balance Adjustment Signal
Screen Size
High light [IRE]
[Vpp]
Low light [IRE]
[Vpp]
Table 1 shows amplitude of White raster (without sync,
termination impedence: 75ohm).
Adjustment Procedure
A. High Light W/B adjustment
(1) Receive signal for High Light white balance ADJ.
(2) Adjust white
(x=0.278±0.004; y=0.280±0.004) at center of screen,
using R DRV/ G DRV with remote control.
B. Low Light W/B adjustment
(1) Receive signal for Low Light white balance ADJ.
(2) Adjust white balance to 21000K-25 MPCD (x
=0.260±0.010, y=0.245±0.010) at center of screen,
using R CUT OFF/G CUT OFF/B CUT OFF with
remote control. Do not touch screen VRs.
(3) Take Green color as a reference color, then adjust
Low Light W/B by increasing other two colors CUT
OFF data. Do not change GREEN CUT OFF data.
CA-100 Probe should be set to a direction as shown
below.
Repeat A & B two or three times, until no adjustment
is needed (white balance tracking-GOOD). If W/B
tracking is not good, set all data (Both DRV and CUT
OFF) to inital data, and change reference color to
different color.
Note: If Low Light adj. spec cannot be followed, apply
previous adj. spec. (adjust by eye.)
Set probe to above direction.
(Screw hole side should
be on the left side)
29
DP23/23G/24
at screen center on 53" 4:3
2
43" 51"
100
0.715
15.0 17.5 20.0
0.105 0.123 0.140
balance to 10800K-7
Screw Hole
Flat Face
Screen
Top view of
CA-100 Probe
57"
MPCD