When researching backlighting technologies used in keypads, you may come across light guides. Light guides are often used in mechanical and membrane keypads. They don’t necessarily produce light. Rather, light guides distribute light across the keypad’s top layer. To learn more about light guides and how they work, keep reading.
A light guide is a backlighting component that’s designed to propagate and distribute light across the keypad’s top layer to the areas where it’s needed. Most light guides consist of a thin layer of material. Whether a keypad uses light-emitting diode (LED) or electroluminescent (EL) backlighting, it can use a light guide as well.
Benefits of Light Guides
With a light guide, a keypad will have brighter buttons or keys that are easier to see. Illumination isn’t needed for all applications. If you’re planning to use a keypad in a dark or otherwise dimly lit area, though, you may want to consider a light guide. This thin layer of material will propogate and distribute the light so that the keypad’s buttons or keys are easier to see.
Light guides can reduce the number of LED or EL bulbs required in a keypad. You won’t have to use as many LED or EL bulbs in a keypad if the keypad has a light guide. Therefore, a light guide can extend the life of a keypad’s backlighting.
Contrary to common belief, light guides aren’t thick or otherwise large. They are very small and consume little or no space. Light guides, in fact, can be designed with a thickness of just 100 microns. With such a small size, light guides are easy to incorporate into nearly all keypads.