Quantum Data 881, User Manual

Page: 1092 / 1144

654 Appendix B Image Reference
After the center of the display is properly converged, the outer areas can be adjusted by
using the monitor’s “Dynamic Convergence” controls. The number of controls, the area of
the screen that they affect and their adjustment procedure is dependent upon the monitor
under test.
Test Sweep linearity adjustment
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
will cause portions of an image to be stretched while other portions will be compressed.
Non-linearity in a monitor can show up in several ways. It may be present across the
entire screen, a large portion of the screen, or it may be localized in a very small area.
Method Adjust the display’s linearity controls so that all of the boxes in the crosshatch are identical
in size. You can measure the boxes with a ruler or with a gauge made for the monitor
under test. Any deviation should be within your specification limits.
Taffeta
Description