Sony VPH-G90U Service Manual page 83

Adjusting the Lens Focus and Scheimpflug
Note
Normally, adjust only the V screw for the green CRT. Adjusting the H
screw is required only for non-standard installation.
If the left and right parts of the screen are not in focus, make sure that the
projector and the screen are installed correctly.
For the red and blue scheimpflug, adjust both the H and V screws.
By turning the V screw, the CRT moves vertically to adjust the vertical tilt
of the focal plane.
V screw
Lens
By turning the H screw, the CRT moves horizontally to adjust the
horizontal tilt of the focal plane.
Lens
Repeat the above process until the upper and lower parts and the right and
left parts of the screen are in focus.
4 Adjusting the green lens focus precisely
After adjusting the green scheimpflug, readjust the green lens focus until
the perfect focus is obtained.
For the procedure of the adjustment, see "1 Adjusting the green lens focus" on
page 81.
Proceed to the red lens focus and scheimpflug adjustments.
84
Adjustments
Up
B A
Moves vertically.
Focal
plane
Screen (Side view)
Right
D C
H screw
Moves horizontally.
D
Focal
plane
C
Screen (Top view)
Adjusting the Red Lens Focus and Scheimpflug
1 Adjusting the red lens focus
1
2
3
B
4
A
5
2 Adjusting the red magnetic focus and AQP/DQP roughly, if necessary.
The magnetic focus and AQP/DQP will be adjusted precisely after the lens
focus and scheimpflug adjustments. Adjust the red magnetic focus and
AQP/DQP roughly at this stage to make the later adjustments easily.
For details of the magnetic focus and AQP/DQP adjustments, see page 87.
3 Adjusting the red scheimpflug
After adjusting the red lens focus, adjust the red scheimpflug (angle of the
red CRT).
Check the tilt of the focal planes at the upper, lower, left and right parts of
the screen, then adjust the focus with the H and V screws on the red CRT.
For details, see "Adjusting the green scheimpflug" on page 83.
4 Adjusting the red lens focus precisely
After adjusting the red scheimpflug, readjust the red lens focus until the
perfect focus is obtained.
For the procedure of the adjustment, see "1 Adjusting the green lens focus" on
page 81.
Proceed to adjust the blue lens focus and scheimpflug.
Reset the centering adjustment data of the red signal.
For details, see "Resetting the Data" on page 138.
Press the PATTERN key until the H-pattern or ME-pattern is
displayed.
Press the CUT OFF G and B keys to display the red signal only.
Loosen the R1 screw, slide it so that the letters H at the center of the
screen are in focus, then tighten the screw.
For details, see "Adjusting the green lens focus" on page 81.
Loosen the R2 screw, slide it so that the letters H at all four corners of
the screen are in focus, then tighten the screw.
Repeat steps 4 and 5 until the red focus adjustment is completed.
85
Adjustments