When researching the different backlighting technologies used in touchscreen devices, you may come across light guides. Whether it’s capacitive or resistive, countless touchscreens use light guides for backlighting. The presence of the light guides helps to illuminate the touchscreen so that it produces visible images. But what exactly are light guides?

The Basics of Light Guides

Light guides consist of thin strands of a transparent material that are used to propagate light. Some light guides are made of glass, whereas others are made of plastic. Regardless, they all consist of thin strands of a transparent material.

They are called “light guides” because they guide light to various areas of the touchscreen device or keypad in which they are used. With that said, light guides don’t produce their own. Rather, they are designed specifically to propagate light from a separate source, such as light-emitting diodes (LEDs). The LEDs produce intense and focused light that travels through the light guides where it’s distributed more evenly across the touchscreen’s display.

Benefits of Light Guides for Backlighting

Being that light guides still require a separate light source, you might be wondering what benefits, if any, they offer when used for backlighting. For starters, light guides promote energy-efficient touchscreen devices. They lower the amount of energy touchscreens consume by reducing the burden placed on the separate light source. If a touchscreen features light guides with LEDs for backlighting, the light guides will help to distribute the light produced by the LEDs. Therefore, fewer LEDs are needed when light guides are used, resulting in greater energy efficiency.

Light guides also promote higher-quality images. Without them, some touchscreens may suffer from areas of uneven color. The touchscreen may produce dark images in some areas and bright images in other areas. For better image quality, light guides can be used. The light guides will distribute the light evenly across the touchscreen’s display to prevent discoloration issues.

Optical Fiber vs Light Guide Backlighting: What’s the Difference?

The terms “optical fiber” and “light guides” are often used interchangeably when discussing thin strands of a transparent material that’s used to propagate light. Optical fiber backlighting, however, specifically involves the use of glass or plastic, whereas light guides may consist of any transparent material. Glass and plastic are popular materials used in the construction of light guides, but you can find light guides in other transparent materials as well, including silicone, PC and TPU.