- a perforated metal plate situated behind the faceplate of a color television picture tube and having holes aligned to insure that each of three electron beams strikes only its corresponding red, green, or blue phosphor dot.
Origin of shadow mask
First recorded in 1950–55
Also called aperture mask.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for aperture mask
From the eyeless sockets of the shadow-mask a phosphorescent gleam shot towards the Grand Chamberlain.Under the Witches' Moon
- television a perforated metal sheet mounted close to the phosphor-dotted screen in some colour television tubes. The holes are positioned so that each of the three electron beams strikes the correct phosphor dot producing the required colour mixture in the image