Light Pen

A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's CRT display.

It allows the user to point to displayed objects or draw on the screen in a similar way to a touchscreen but with greater positional accuracy. It was long thought that a light pen can work with any CRT-based display, but not with LCDs (though Toshiba and Hitachi displayed a similar idea at the "Display 2006" show in Japan) and other display technologies. However, in 2011 Fairlight Instruments released its Fairlight CMI-30A, which uses a 17" LCD monitor with light pen control.


Since light pens operate by detecting light emitted by the screen phosphors, some nonzero intensity level must be present at the coordinate position to be selected, otherwise the pen won't be triggered.

Read more about Light PenHistory, Trivia

Other articles related to "light pen, pen":

Touchscreen - History
... was a high-end musical sampling and re-synthesis workstation that utilized light pen technology, with which the user could allocate and manipulate sample and synthesis data, as well as ... The later Fairlight series IIT models used a graphics tablet in place of the light pen ...
Jeopardy! In Merchandising - Gameplay - Final Jeopardy! Round
... version premiered in 1984, contestants have used a light pen to write down their Final Jeopardy! wagers and responses ... Contestants are also provided with a pen and index card in the event of a malfunction with the light pen this occurred on one episode that aired in May 2008 ... The light pen is automatically turned off at the conclusion of the 30-second period ...
Computer Graphics - History - Initial 1960s Developments
... A light pen could be used to draw sketches on the computer using Ivan Sutherland's revolutionary Sketchpad software ... Using a light pen, Sketchpad allowed one to draw simple shapes on the computer screen, save them and even recall them later ... The light pen itself had a small photoelectric cell in its tip ...
Light Pen - Trivia
... game show Jeopardy! began in 1984, contestants have used a light pen to write down their wagers and responses for the Final Jeopardy! round ...

Famous quotes containing the words pen and/or light:

    This is no rune nor symbol,
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    As I sat before the fire on my fir-twig seat, without walls above or around me, I remembered how far on every hand that wilderness stretched, before you came to cleared or cultivated fields, and wondered if any bear or moose was watching the light of my fire; for Nature looked sternly upon me on account of the murder of the moose.
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