English: Drawing of an early television studio in the 1930s using mechanical flying spot scanner television cameras, owned by the Jenkins Television Co. During the 1920s and 30s, before modern electronic-scanning television systems debuted around 1940, dozens of experimental stations broadcast television programs using mechanical scanning technology. Instead of a television camera that recorded an image, a powerful light source called a "flying spot scanner" (bottom) projects a moving spot of intense light onto the subject (top) in the darkened studio. A spinning disk in the scanner pierced with small holes, called a Nipkow disk, scans the light beam across the subject in a raster pattern. The light reflected off the subject by the spot is picked up by banks of photo cells near the subject. The photo cells produce a varying signal proportional to the brightness of the spot on the subject where the beam strikes. This becomes the video signal broadcast by the transmitter (left). To the left is also visible a television movie projection camera, used for broadcasting movies from film.

Alterations to image: Added label "NIPKOW DISK" to flying spot scanner, and "PHOTO CELLS" to second bank of photocells that weren't labelled.