Hitachi C47-WD8000 Service Manual page 43

SERVICE ADJUSTMENTS
(6) In case of B lens.
Set the position where the chromatic aberration change from purple to green.
As shown below, observe the vertical bright line and adjust lens focus where the
purple or green chromatic aberration slightly appears inside and purple or green
outside (reference value : 1~3mm) at the point specified in table below.
Change the signal and fine-adjust in the same way as the G lens.
O
OPTICAL FOCUSING ADJUSTMENT BLUE
LENS
SCREEN SIZE
(ASPECT RATIO)
PITCHES from CENTER
SIDE
COLOR
I
ABERRATION
O
(NOTE) * Slightly reddish or no color
** Slightly bluish or no color
(NOTE 3)
Setting to the center between purple and green is optimum.
(7) After all colors have been adjusted, display all colors with the cross-hatch pattern
signal and compare the focus (optical focus) performance with the limit sample
set.
(8) Then, select the circle pattern signal and compare the focus (optical focus)
performances of each color and all colors together with the limit sample set.
(9) If the focus performance is worse than the limit sample set,
re-adjust step (1) to (6).
L
I
HSA
43"(4:3) 47"(16:9)
4.0 3.0
*
*
(2.0mm MAX) (4.0mm MAX)
**
(2.0mm MAX) (4.0mm MAX)
HSA
50"(4:3) 57"(16:9)
3.0
* *
* *
(4.0mm MAX) (4.0mmMAX)
** **
(4.0mm MAX) (4.0mmMAX)
43
D250
52"(16:9）
INCH
CROSS-HATCH
3.0 2.0
PITCHES
** **
** **
REFER TO
(4.0mm MAX)
NOTE BELOW
* **
(4.0mm MAX)
UNIT