What Is a Light Pen?

Also called photoelectric pen, a device that reads special forms of data, such as bar code records, into a computer system by using light and photoelectric tubes. Its appearance is similar to a pen, so it is commonly called a light pen. ^[1]

Light pen

Light pens work in two ways: pointing and tracking. ^[2]

Generally, light pens serve three purposes:

Use the light pen to complete a variety of complex functions such as drawing, changing pictures, rotating graphics, and zooming in and out, which is very useful in engineering design;

Make "menu" selection to form a human-computer interaction interface;

Auxiliary editing programs to achieve editing functions. Light pens are important input devices in systems such as computer-aided publishing. (With fiber optic connector

Light pen

The introduction of red light into the fiber can be used as a comparison of the core wires in a multi-core optical cable; check the fiber failure points (breakpoints, beginning or end of the fiber characteristics) that OTDR cannot find and high loss sections due to microbend . For example: fiber optic jumpers, pigtails, fiber cores in the junction box or bare fibers (plain wires), etc. )