<Now Go Bang!> Raster CRT Typography (According to DEC)
The time it takes for the phosphor to become fully activated is actually longer than the pulse representing the timing to draw a single pixel (40 nanoseconds). Meaning, if we were to attempt to display just a single pixel, the phosphor on this particular spot will never reach its full activation level resulting in a fuzzy image of varying brightnesses between dimmer, thin strokes and heavier, thick strokes. So the typography has to adjust for this, by streching the pulses to double width (80 ns), at least, in order to provide an even image and legible text and to work around the shallow flanks of the screen intensification.