Lens Focus Adjustment - Hitachi 60DX10B Service Manual

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2.4 LENS FOCUS ADJUSTMENT

Adjustment preparation
(1) The orientation of PTV set is arbitrary, west,
east, north and south.
(2) Centering DY inclination should have been
adjusted.
(3) FOCUS VR location adjustment should have
been completed. (Red : 12 OÕclock, Green : 1~2
OÕclock).
(4) Receive the cross-hatch pattern signal.
(5) Refer to setup below.
CONTRAST : HALF of full scale.
BRIGHTNESS : minimum
Adjustment procedure
(1) Loosen the fixing screw or wing nut on the lens
cylinder so that the lens cylinder can be turned.
(Be careful not to loosen too much).
completing steps (4), (5), (6) below, tighten the
fixing screws or wing nuts for each lens with a
torque of 1.18N.m (12Kgf cm) ~ 1.67N.m (17Kgf
cm).
(Be careful the lens cylinder does not turn after
having tightened the screw or wing nuts. If it is
tightened too much, lens may tilt or screw may
break.)
Lens Assy
(NOTE 1)
Fixing Screw
TYPE 1
(2) Apply covers to each color of R, G and B lenses.
And project a single color on the screen and
adjust in sequence. (The adjustment order of R,
G and B is only an example.)
(3) If the lens adjustment knob is turned clockwise
viewed from the front, the color Aberration
change as follows.
*1
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3 2 1
There is no picture fold.
After
Lens Assy
(NOTE 2)
Fixing Wing Nut
TYPE 2
Cross-Hatch
RED LENS
GREEN LENS
BLUE LENS
(4) In case of G lens. Set to the point where the
chromatic aberration switches from blue to red.
If the chromatic aberration appearing all over
the screen is not the same, observe the vertical
bright line and adjust lens focus as specified in
table below. When the red chromatic aberration
appearing at both sides of the bright line is not
equal, observe the side with larger chromatic
aberration when adjusting.
OPTICAL FOCUSING ADJUSTMENT GREEN
CHASSIS
SCREEN SIZE
L1 and L2
(PITCHES from CENTER)
L1&L2
COLOR
ABERRATION I
O
(NOTE) * Slightly reddish or no color
** Slightly reddish or no color
Change the signal to the circle pattern and fine
adjust. Observe the corner part of the screen,
especially observe number in the small circle
when adjusting. If the focus performance at the
screen center exceeds the lower limit, it is
acceptable.
Small circle of circle pattern
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Color
Aberration
Change of Color Aberration
Short focus Long focus
Orange Scarlet
Blue Red
Purple Green
L1 L2
O
I
43GX10B/50GX10B 50DX10B/60DX10B
43Ó 50Ó 60Ó 50Ó
3.0 3.0 3.0 3.0
* * * *
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2mm MAX 3mm MAX 3mm MAX 3mm MAX
* ** ** **
2mm MAX 3mm MAX 3mm MAX 3mm MAX