GME PG-28, Руководство пользователя

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The DOT pattern is preferred for checking static convergence. Static convergence is always
performed before and after purity adjustments.
STAIRCASE
The STAIRCASE pattern displays six equal-width vertical bar steps of increasing luminance
from left to right.
This pattern is useful in checking amplifier linearity. The increment of amplitude from one
step to the next should be equal. Non-equal steps represent non-linear distortion. Typical
luminance nonlinear distortions will result in a loss of grey-scale distinctions, which means
that detail is loss.
Each of the vertical bars should have distinctive brightness level. The display is too dark
when the black vertical bars blend together. The display is too bright when the white vertical
bars blend together. Adjust the display cutoff/bias controls and drive/gain controls so each
vertical bar has distinctive brightness level.
This pattern is also useful for checking and adjusting the grayscale performance of a video
device. This pattern is seen as a primary color (red, green, or blue) tint on display device with
poor grayscale performance.
CIRCLE
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This pattern shows a 4:3 aspect ratio circle that is perfectly round and one horizontal line and
one vertical line that are perfectly straight. Use this pattern to determine your video
equipment’s alignment for a 4:3 aspect ratio display. There should be a perfect circle centered
on your display with a horizontal line and a vertical line intersecting at the center of the
screen. This test can be used to test a misaligned deflection coil as well. If the monitor
displays the test pattern off to one side, this would indicate an improper centering adjustment.
Titled lines or squeezing of the circle indicate problems with the display device. Check for
tilted line to determine the areas of the monitor where the display is not consistent.