Jeff Krause, Product Development Consultant

    Light Pipe and LCD Back Light Design

Designers of Light Pipe designers of LCD Back lights designers of light-pipes designs LCD back lights designs Light-Pipes designs LCD back-light design

  What is a "Light Pipe"?
  Light pipes are semi-transparent parts that are used to conduct light from a source
  (Typically an LED of an electronic device) to almost any desired position on the product.

  Since LEDs (Light Emitting Diodes) are most economically mounted directly on the
  PCB (Circuit Board of the product), light pipes are used in situations where the output
  position desired for an indicator is too remote to allow simply viewing the LED directly.
  You probably need to look no further than your own computer printer to find an example.

  Light pipes transmit and reflect/refract the light internally within their semi-transparent bodies.
  Unless the geometry is very simple (a strait tube), thorough knowledge of light transmission,
  reflection, refraction, texture and wavelength effects is required to develop efficient designs.

  The additional requirement to make such a part easily moldable without destroying
  the desired optical qualities can complicate this challenge even further.

  What is a "Back Light"?
  The type of back light referred to here is used to conduct light from a source
  (Perhaps an array of LEDs) and disperse the light evenly beneath the surface of an
  LCD (Liquid Crystal Display) to allow viewing the display in low-light conditions.

  Such separate back lights are an economical and necessary option for smaller,
  custom-sized LCDs that do not have conventional backlight options available.

  The design requirements are similar to a very large light pipe. However because the desired
  effect is to illuminate a relatively large area very evenly, the design challenge is greater still.

  Illumination (Ray-Trace) 3D computer simulation is the method I use to sort through the
  design possibilities; Followed usually by prototyping to verify the results in the real world.
  I use the advanced Trace ProTM simulation software for the most difficult work.