Table of Contents
Advertisement
980 DP 1.4 Video Generator / Analyzer - User Guide
16.101
Linearty (Linearity)
16.101.1
Description
This image has three parts. The first part consists of six (6) 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 smaller circle is drawn at half the
diameter and concentric with the larger circle. 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 at every other pixel location. Every fifth mark is slightly longer. The color of the pattern
can be changed with the individual video output controls.
16.101.2
Test
Linearity adjustment.
16.101.3
Purpose
To present 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 present across the
entire screen, in a large portion of the screen, or localized in a very small area.
16.101.4
Method
The circles in the image can be used to do a general adjustment of a monitor's linearity controls. Adjust the
controls to form perfectly round circles. The crosshatch image can be used to measure linearity and to make finer
control adjustments. All the full boxes in the crosshatch should be identical in size. Measure them with a ruler or a
gauge made for the monitor under test. Any deviation should be within your specification limits. Use the tic marks
Page 412
Rev. A1
June 16, 2017
Advertisement
Table of Contents
