What is Light Pen and its functions ?

What is Light Pen?

There are two intents from the light pen. The first light pen, which has a battery, has an LED lamp on its upper part. This lamp is so that even if you do not have light, you can also write it from this pen.
In other words, the light pen is meant to be used in photography, which is used to light a picture to improve any picture.
Third, the tablet pen and the fourth and the last, most commonly used for working on computer.
A light pen is a computer input device, which is in the form of a light-sensitive wand used in conjunction with a computer's cathode-ray tube (CRT) display.
A light pen detects changes of brightness of close screen pixels once scanned by CRT ray and communicates the timing of this event to the pc. Since a CRT scans the entire screen one pixel at a time, the computer can keep track of the expected time of scanning various locations on screen by the beam and infer the pen's position from the newest timestamp.

Who invented computer light pen?

The first light pen was created around 1955 as a part of the whirlwind project at Massachusetts Institute of Technology(MIT). Its prototype was prepared in 1950 in the US.
During the Sixties light pens were common on graphics terminals like the IBM 2250, and were also available for the IBM 3270 text-only terminal.
In the early 1980s, Light pen was used mostly in music workstations such as the Fair light CMI and personal computers such as the BBC Micro. For the MSX computers, Sanyo created a light pen interface cartridge.

What are the functions of light pen?

When working on a computer, the light pen is used as a receptor.
Pressing the button in it brings a computer display and works. It creates pixels on the screen.
The electronic device attached to it creates an image from the light on the screen.
From this pen you can work on a computer screen in exactly the same way, like pencils on paper.
The only difference is that the mouse and fingers in your hand are on the keyboard.

Why is light pen used less in present time?

In the eighties of the decade, its use has increased greatly for working on computers. But since it was an external device and working on a computer, it has to be handled separately, so its use was reduced and the device was made in the computer system itself. Although it is still used today Apart from this, it also comes in some other industries.