Because instead of a CRT and its associated electronics, they featured a spinning disk with a spiral pattern of holes. These mechanical TV systems were quickly superseded in the 1930s by all ...

Inventors attempted to build mechanical television systems based on Pail Nipkow’s rotating disks. Inventors attempted to ...

For his Nipkow clock, though, [Joe] turned the idea around and placed a light source behind the rotating disk. Controlling ... If only the early mechanical TV tinkerers had had such help.