Light Guide Plate
08
May

What is a Light Guide Plate (LGP)?

A Light Guide Plate (LGP) is a thin, transparent sheet made from otical grade acrylic (PMMA). It is designed to distribute light evenly across its surface by guiding light from edge-mounted LEDs and emitting it perpendicularly through its front face. LGPs were originally developed for LCD backlighting but have become a core component in modern architectural and decorative lighting.

The unique value of an LGP lies in its ability to transform directional LED light into a wide, uniform, and soft light source without glare, even in ultra-thin luminaires.

How Does LGP Work?

  1. Edge-Lit Illumination: LEDs are placed along one or more edges of the plate.
  2. Internal Reflection: The light enters the LGP and bounces internally due to total internal reflection.
  3. Patterned Extraction: Micro-patterns are applied with laser machine to the surface of the plate to scatter the light outward in a controlled manner.
  4. Uniform Output: These patterns are engineered to compensate for light loss across the plate, ensuring brightness uniformity from edge to center.

This mechanism allows for extremely slim lighting solutions, minimizing the need for bulky housings.

Precision Engineering of Dot Patterns

To ensure optimal light extraction and uniformity, the dot patterns on an LGP are carefully calculated using optical design software. The software models the light behavior within the plate, adjusting dot size, density, and distribution based on the LGP’s dimensions, LED placement, and desired luminance profile.

  • Dot Size and Spacing are gradually varied to compensate for the reduction in light intensity farther from the LED source.
  • Simulation Software with proprietary algorithms simulate multiple configurations before selecting the optimal pattern.

Once the pattern is finalized, it is transferred to production using laser engraving technology:

  • A high-precision laser plotter engraves microdots directly onto the surface of the clear acrylic sheet already cut to size.
  • The laser intensity and pulse frequency are adjusted to create patterns with consistent depth and size.

Laser-engraved patterns offer superior durability and consistency over printed patterns, especially in environments requiring longer product life and stable optical properties.

For more technical data, sample requests, or collaboration opportunities, please contact us.