Traditionally, most people navigate around their computers with a mouse.
The mouse can be either attached to the computer or wireless, and serves
as the point and click (and in many cases drawing) tool for PC users.
There are other ways to communicate with the computer, however, and one
of these is called a light pen. A light pen is a computer
input device that is used hand in hand with the computer
monitor. It is called a light pen because its action is activated
by light, therefore it is light sensitive. It is important to note, however,
that a light pen cannot work with LCD
screens, only traditional monitors. It may be hard to imagine, but
the light pen actually became moderately popular in
the early 1980’s when it was first used in sync with synthesized
music. Another interesting fact about this modern marvel is that
it is used in the popular television
game show Jeopardy during the
final round when contestants are writing their final questions on the
blue screens for the winning bid.
Because of its name, many people might be led to believe that light
pens emit or project some sort of light from them, and that is what
causes the interaction between the pen itself and the computer
screen. The fact is, however, that it is just the opposite. The light
pen feeds off of light being emitted from the computer
screen. Once the user pushed the button that is attached to the pen,
wherever it is pointed illuminates on the screen. Another name for the
light pen is “selector pen”, since whatever it is pointed
at selects the object on the screen. This ingenious little invention
was actually created in the 1950’s and is still commonly used in
many homes and industrial environments today.