light valve

noun

, Electricity.

1. a light-transmitting device having transmissions that vary in accordance with an electric input, as voltage, current, or an electron beam, used chiefly for recording sound on motion-picture film.

Word History and Origins

Origin of light valve¹

First recorded in 1925–30

Example Sentences

It will be noticed that a light valve-spring is shown in drawing.

From Project Gutenberg