This is an actual image of a cathode-ray tube, “the furthest advance yet made in man/ machine interface,” used for a high-speed printer/plotter. It’s enlarged six times. Or the display is, at least. The Fairchild Du Mont company wants us to know that this tube has that kind of resolution.
This is an ad for the Du Mont Type KC2515 CRT, a screen with a resolution of 0.0015 inches, as it appeared in the July/August 1966 issue of the Journal of the Society for Information Display, which I found on archive.org.