Light tubes in electronic devices

Molded plastic light tubes are commonly used in the electronics industry to direct illumination from LEDs on a circuit board to indicator symbols or buttons. These light tubes typically take on a highly complex shape that uses either gentle curving bends as in an optic fiber or have sharp prismatic folds which reflect off the angled corners. Multiple light tubes are often molded from a single piece of plastic, permitting easy device assembly since the long thin light tubes are all part of a single rigid component that snaps into place.
Light tube indicators make electronics cheaper to manufacture since the old way would be to mount a tiny lamp into a small socket directly behind the spot to be illuminated. This often requires extensive hand-labor for installation and wiring. Light tubes permit all lights to be mounted on a single flat circuit board, but the illumination can be directed up and away from the board by several inches, wherever it is required.

Light tubes or light pipes are physical structures used for transporting or distributing natural or artificial light for the purpose of illumination, and are examples of optical waveguides. In their application to daylighting, they are also often called tubular daylighting devices, sun pipes, sun scopes, or daylight pipes. Light pipes may be divided into two broad categories: hollow structures that contain the light with a reflective lining, and transparent solids that contain the light by total internal reflection.
Generally speaking, a light pipe or light tube may refer to:

• a tube or pipe for transport of light to another location, minimizing the loss of light;
• a transparent tube or pipe for distribution of light over its length, either for equidistribution along the entire length (see also sulfur lamp) or for controlled light leakage.

Both have the purpose of lighting, for example in architecture.