Definition of light pen in US English:

light pen

noun

  • 1A handheld, penlike photosensitive device held to the display screen of a computer terminal for passing information to the computer.

    • ‘The light pens are compatible with any DOS or Windows application and IBM computers in general.’
    • ‘You may have to adjust the brightness of your monitor to get your light pen to work properly.’
    • ‘The radiated light is directed so as to be projected from a tip of the light pen as required.’
    • ‘Digital tablets combine the tactile sensation of light pens with the ease of use of a mouse.’
    • ‘Various other light pens have been developed which include a lens for focusing the axially received light.’
  • 2A handheld, light-emitting device used for reading bar codes.

Pronunciation

light pen

/ˈlīt ˌpen//ˈlaɪt ˌpɛn/