Quantum Data 700A - Manual (Page 20)

20 Model 700A, 701A Quick Start Guide
Flat_Wht/(R,G,B)
Description - Fills the screen with white, blue (B), green (G) or red (R).
Application - Use to test chrominence.
Grid
Decription - White crosshatch on a black background. The lines form square boxes. A single pixel dot
is located in the center of each crosshatch box.
Application - Use the Grid pattern to test convergence. To accurately produce an image on a color
monitor, the three electron beams in the CRT must meet (converge) at the same location at the same
time. Lines displayed on a misconverged monitor appear as several multi-colored lines, and the
transitions between different colored areas contain fringes of other colors.
Rev_Grid
Description - Black crosshatch drawn on a white background. The lines form square boxes.
Application - Use to test convergence. To accurately produce an image on a color monitor, the three
electron beams in the CRT must meet (converge) at the same location at the same time. Lines
displayed on a misconverged monitor appear as several multi-colored lines, and the transitions
between different colored areas contain fringes of other colors.
Overscan
Description - The image has three parts. The first part consists of five white circles. A large circle is
drawn in the center of the screen. Its diameter equals the lesser of the video height or width of the
display. A circle also is drawn in each of the corners of the screen. The diameter of the corner circles
equals one-fifth of the display width.
The second part of the image consists of a white crosshatch. The number of boxes in the crosshatch
depends on the physical size of the display.
The last part of the image consists of white tic marks on the horizontal and vertical center lines of the
image. The marks are one pixel thick. Every other mark is slightly longer. The color of the pattern can
be changed with the individual video output controls.
Application - Used for detecting non-uniformity and non-linearity. The image presents an undistorted
display, the horizontal and vertical sweeps of the electron beam across the face of the CRT should be
at uniform speeds. Any non-uniformity in the sweep causes portions of an image to stretch while
other portions are compressed. Non-linearity in a monitor shows up in several ways. It may be
Pattern Descriptions