Light Guide, Light Pipe, Light Diffuser: How Are They Different?

Posted by on Nov 15, 2022

lightpipe vs lightguide vs light diffuser

Explore the Key Differences Among Light Guides, Light Pipes and Light Diffusers

There are many similar phrases and terms used across the fields of backlighting, illumination and light guide design. This can make it difficult to understand product options and their applications.

It’s important to clear up any confusion before you begin a project or work with an illumination partner. Let’s look at the differences between a light pipe, a light guide and a light diffuser. Read on to discover the key differences and help shed some light (pun intended) on the subject.

Light Guides

A light guide manipulates – aka guides – the light to illuminate over a larger surface area. Light guides are made from optically clear polymers like polycarbonate or acrylic.

Light guides take light from a single LED source and illuminate it evenly and efficiently over the entire surface of a Liquid Crystal Display (LCD). They are also able to take the focused light from an LED and spread it evenly and change its shape or distribution to achieve the desired result. This is seen with LCD illumination of logos, overlays or other large areas. There are many light guides for B2B applications to consider.

Light Pipes

In light guide design, a light pipe transports light from a light-emitting diode(LED) source to an emitting area, typically on a different surface or separate area from the actual location of the LED. Light pipes, like light guides, are made from an optically clear polymer, such as polycarbonate (PC) or acrylic (PMMA).

The main application for light pipes is to illuminate small areas such as power indicators while maintaining the focus of the LED intensity to a high degree.

Light pipes are used to simulate the LED being at the top surface of the product, even when positioned on a Printed Circuit Board (PCB) below the surface. Further, long lines of light can be created by using long square or cylindrical tubes to emit light in radial patterns down their length.

Light Diffusers

A light diffuser reduces the intensity of light from an LED point source and spreads it over wider viewing areas. As opposed to light guides and light pipes, a light diffuser will be made from an optically opaque material.

Light diffusers are used to increase the viewing angle of the light being emitted, and to spread that light out over larger areas. They can be placed directly over an LED, or at a further distance. Light diffusers can also be used as the top surface of a light guide or light pipe.

We’re the worldwide leader in producing high-end, custom light guide solutions for many industries, from automotive and consumer electronics to egress lighting and medical.

Connect with our experts to learn more about how we can help with a custom light guide solution.

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