Light pipes are clear tubes that transmit light from a light source, such as an LED, to a user interface. Designed to carry light short distances with high efficiency, light pipes can bend light around corners and tight spaces providing good visual indication with minimal loss of light intensity.
When designing light pipes into an application, light pipes should be placed very close to the light source on one end of a PCB. The optical-grade materials of the pipe help carry the rays of light to the desired destination, typically at the user interface or front panel of a device.
Light pipes transmit roughly 80 to 90 percent of the light from the LED source, depending on design and spacing. The closer the light pipes are to the LEDs, the more efficiently they can transfer light.
When designing for light pipes, please consider the minimum allowance distance between the light pipe and the light source, because there may be a certain amount of heat produced by the LED or light source which can harm the light pipe if not accounted for.