676 Appendix B Image Reference
An example of the primary version of the Persist image is shown below:
Test Phosphor persistence
Purpose The phosphors on the face of most CRTs continue to glow for a short period of time after
the electron beam has stopped energizing them. This phenomenon is called persistence.
A certain amount of persistence is desirable in most applications. It prevents a flickering of
a displayed image that most users would find objectionable. On the other hand, a CRT
with an overly long persistence time causes moving objects to leave a blurred trail.
Method A flickering in the slower moving boxes indicates that the combination of refresh rate and
phosphor persistence is not suitable for long-term viewing.
A fading tail left behind by the faster moving boxes indicates that the display may not be
suitable for viewing animated images.