scanning disk

American  

noun

Television.

1. (in mechanical scanning) a disk with a line of holes spiraling in from its edge, rotated in front of a surface so as to expose a small segment as each hole passes before it for transmitting or reproducing a picture.

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Etymology

Origin of scanning disk

First recorded in 1925–30

Example Sentences

Lenses combine those col ors and a second scanning disk synchronized with the first paints a colored x-ray image on a screen.

From Time Magazine Archive

A television scanning disk looks over the grey shadows piece meal, lets them illuminate three photo electric cells.

From Time Magazine Archive