As opposed to mechanical television? We had the technology, though it was packet-switched instead of broadcast (you could broadcast to all medium endpoints) and had a really, really low frame rate:
As opposed to mechanical television? We had the technology, though it was packet-switched instead of broadcast (you could broadcast to all medium endpoints) and had a really, really low frame rate:
I’ve even heard of artillery shell television.
An artillery round with a photo-sensor modulating a radio signal sends a stream of data that can be reconstructed into an image of the terrain below. (Be aware that the round is rotating! Sky-Earth/Sky-Earth/Sky-Earth/ ...)
Actually, mechanical display devices with spinning mirrors may yet make a comeback.
They're a good way to produce a three-dimensional image that can be viewed without special glasses.