I saw some at a hamfest. I lost my interest as I
figured out that they
operated the same way as most VCR displays.
Not at all!
The Minitrons are incandescent displays. The light comes from a hot
filament wire, like a light bulb.
Most VCRs (at least over here) use vacuum fluorescent displays. They're a
bit like directly heated triode valves with fluorescent compounds on the
anode (plate). There's a filament (or two) across the front of the
device, operated below red heat, so you don't see it glow. The anodes are
the shape of the segments and other symbols and glow when hit by
electrons emitted by the filament. And there's a grid between them.
Normally corresponding segments of the various digits are connected
together inside the device, the grids are used to select a particular
digit -- it's a stnadard multiplexred drive.
[One of my VCRs has a load of LED 7 segment displays on the front, but
that's another story...]
-tony