light pen

noun

, Computers.

1. a handheld light-sensitive device used for pointing at characters or objects on a CRT in order to make or modify drawings or to indicate functions to be performed.

light pen

noun

1. computing
   1. a rodlike device which, when applied to the screen of a cathode-ray tube, can detect the time of passage of the illuminated spot across that point thus enabling a computer to determine the position on the screen being pointed at
   2. a penlike device, used to read bar codes, that emits light and determines the intensity of that light as reflected from a small area of an adjacent surface

Word History and Origins

Origin of light pen¹

First recorded in 1955–60

Example Sentences

When you are firing out at night, the red tracers go out into the blackness as if you were drawing with a light pen.

From The Daily Beast

The light-spot cursor and joy-stick method replace the light pen in this case.

From Project Gutenberg

A light pen held against a particular part of the display pattern can be used to signal the computer.

From Project Gutenberg

Made of fine and light pen steel, and works as well in shirt sleeves as with a coat on.

From Project Gutenberg