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VP400 Series Video Pro
Form7343A
Operation Manual
23
Horizontal Staircase (H_Stair)
Pattern Description
:
Eleven equal-width horizontal bars step from 100 IRE white at the top of the pattern to black at
the bottom (7.5 IRE for NTSC, 0 IRE for all other formats), forming a horizontal staircase.
Pattern Usage
:
The H_Stair pattern is useful for visually checking
gray-scale tracking performance of a display,
especially a projector with red and blue overdrive
at the sides of the display, due to insufficient
correction for CRT side-to-side placement (with
green in the center). Poor grayscale tracking
performance is seen as a primary color tint (red,
green, or blue), at the bright top or dark bottom of
the pattern. To avoid the effects of color overdrive
at the sides of the display when checking
grayscale tracking, observe the top-to-bottom
center of the display. To check the effects of color
overdrive at the sides of the display, observe by eye or use a color analyzer to check the color at
the left, center, and right end of one horizontal bar.
Linearity
Pattern Description
:
Linearity is a combination pattern including circles and lines on a black raster background. The
pattern includes circles in each corner and two circles positioned in the center. A large center
circle extends to the top and bottom of the pattern. Crosshatch lines form 16 squares horizontally
and 12 squares vertically and properly shaped circles on a display in a 4:3 aspect ratio. When
viewed on a display in a 16:9 aspect ratio, the pattern appears stretched horizontally.
Pattern Usage
:
Use the linearity pattern for deflection linearity
testing and alignments. Use to set geometry
controls on displays. Use for color convergence
adjustments.