Adjusting The Color Balance; Adjusting The Focus - Ikegami HTM-1990R Operation Manual

(4) Adjusting the color balance

a) Color balance
For the component signal (YPbPr/RGB), adjust the
color balance using CHROMA only. If the NTSC
decoder module DE-811 is mounted, input NTSC
composite signal, and adjust the color balance
using HUE/CHROMA.
b) Adjustment procedure 1 (NTSC composite signal)
① Input signal
Input SMPTE color bar signal or the NTSC 75%
color bar signal similar to it.
e a
f b
Fig. 4-6-3. NTSC 75% Color Bar Signal
② Starting
Set the screen to blue only using the SCREEN
switch.
* As the luminance difference is hard to discern
when the screen is bright, dim the
surroundings as much as practical and lower
the BRIGHTNESS manually until the blue
signal is slightly visible. This will help make
more accurate adjustment.
③ Adjusting HUE
Adjust HUE so that the parts a to d in Fig. 4-6-
3 become the same brightness.
If they do no become the same brightness, set to
the optimum state, and next adjust CHROMA.
④ Adjusting CHROMA
Adjust CHROMA so that the parts e to h in Fig.
4-6-3 become the same brightness.
If they do no become the same brightness, set to
the optimum state, and adjust the HUE as
described in step 3.
⑤Repeat adjustments ③ and ④ until a to h become
the same brightness.
c) Adjustment procedure 2 (Component signal)
① Input signal
Input the 100% color bar signal to the YPbPr input.
a b
Fig. 4-6-4. 100% Color Bar Signal
Blue
c g
d h
Black
c d
② Starting
Set the screen to blue only using the SCREEN
switch.
* As the luminance difference is hard to discern
when the screen is bright, dim the
surroundings as much as practical and lower
the BRIGHTNESS manually until the blue
signal is slightly visible. This will help make
more accurate adjustment.
③ Adjusting CHROMA
Adjust CHROMA so that the parts a to d in Fig.
4-6-4 become the same brightness.
If the input signal is 75% color bar signal ( a is
100% white and the parts b to d are 75%), adjust
CHROMA so that the parts b to d become the
same brightness.

(5) Adjusting the focus

a) Focus
FOCUS
SCREEN
Fig. 4-6-5. Flyback transformer
b) Precautions
The flyback transformer provides the CRT with 26-
kV high voltage. Only qualified service engineers
may access this device. Enough care must also be
paid not to touch any other parts than the controls.
c) Adjustment procedure
① Starting
Turn off the power and detach the monitor's top
cover. Turn on the power again and heat-run the
transformer for about 20 minutes.
② Input signal
Select a fine signal that gets characters displayed
over the entire screen or a character signal among
the built-in test signals.
③ Adjusting FOCUS
Adjust FOCUS 2 (static focus) in Fig. 4-6-5 to
optimize the focus at the screen center. Adjust
FOCUS 1 (dynamic focus) to adjust the focus at
the screen corners. The FOCUS 1 and 2 affect each
other. Adjust these focus controls alternately until
the optimum focus is achieved over the entire
screen.
27
FOCUS 1 （Dynamic）
F1 FOCUS 2 （Static）
F2
SCREEN