With bad frequency adjustment from left to right, parts of the picture appear blurred. Each alteration of
the frequency increases or decreases the number of blurred fields. Correct setting is achieved when
the whole screen has the same appearance. The picture may appear blurry, but it should be
homogeneously across the whole screen. Blurry or messy lines will be compensated for by phase
adjustment.
bad frequency adjustment correct frequency adjustment
NOTE When DDM compatible timings are used, frequency adjustment may not get modified.
Frequency has to be set to 2816. All graphic adapters which are used in air traffic control
(ATC) use this setting.
3.3.2 Automatic Phase Adjustment
During normal operation, the monitor will heat up, causing marginal phasing between the pixel clock
and the video signal. Enabling the automatic phase adjustment in the OSD will allow the monitor to
compensate this. This function performs tests every 5 minutes for phasing in the pixel clock and
readjusts itself if a deviation is detected.
NOTE For best results, the automatic phase adjustment function requires that text or lines are visible
on the screen. These areas are used to evaluate the degree of phasing.
The monitor has an integrated automatic backlight control function which keeps backlight brightness
constant. If this function is enabled, the backlight value of the OSD is scaled to “cd/m²”.
This mode allows the user to set the backlight brightness to a value between 30 and 150 cd/m².The
TFT module’s maximum brightness is 210 cd/m² (with new backlight tubes). The difference from 150
to 210 cd/m² is used to compensate for old-age brightness leakage of the backlight tubes.
If automatic brightness control is disabled, the value can be set between 0 and 100 %.
3 Operation and Adjustment 41