Light guides are useful when light needs to move from one location to another inside an assembly. Instead of mounting an LED directly at every illuminated point, designers can couple light into a transparent component and control where that light exits.
Source Coupling
Getting LED Light Into the Guide
The relationship between the LED and guide entrance affects how much light enters the transparent structure. Source size, gap, angle, guide shape, interface geometry, and surrounding reflective surfaces can influence coupling.
Internal Transport
Keeping Light Inside the Guide
Transparent guide geometry can direct light along a path using controlled internal reflections. Bends, surfaces, interruptions, attachment features, and material interfaces can alter that path.
Output Features
Extracting Light Where It Is Needed
Surface texture, printed patterns, molded features, geometry changes, scattering structures, and reflective backing can encourage light to leave the guide at selected positions.
Extraction features may vary across the guide to improve brightness uniformity along its length.
Edge Lighting
Illuminating Panels From the Side
Flat light-guide panels can receive light along an edge and redistribute it across a broader surface. This allows the LEDs to remain around the perimeter rather than directly behind every illuminated area.
Transparent Polymers
Acrylic and Other Optical Plastics
Light guides can be made from transparent polymer materials that can be machined, formed, molded, or fabricated into specialized shapes.
Acrylic fabrication can support custom transparent components where the material and manufacturing method match the optical requirements.
Flat stock may also originate from plastic sheet manufacturers before being cut or machined into guide structures.
Mechanical Integration
Holding the Guide Without Blocking the Light
Tabs, clips, frames, bosses, fasteners, adhesives, and housing features can retain the light guide. These mechanical structures should be positioned so they do not unintentionally interfere with the optical path or output surface.
Applications
Where Light Guides Fit
Machine Indicators
Route light from internal LEDs to visible status areas.
Control Panels
Create illuminated legends, icons, or edge features.
Linear Lighting
Guide illumination along narrow mechanical structures.
OEM Products
Move light through custom housings where direct LED placement is difficult.
Selection