Weird old tech. This is the Raytheon Symbolray monoscope, in use at the end of the 1960s. It was kind of like a CRT, but instead of drawing characters directly on screen, it shot electron beams at a metal plate stencilled with tiny characters. The beams were "collected", and converted into an analog video signal corresponding to the printed characters the beams hit.
More here: https://tubetime.us/index.php/2018/06/04/a-vacuum-tube-rom/