Light Guide Panel Particle Gradients for Uniform Luminance

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Solution Overview

Problem

Existing lighting devices using light guide panels suffer from non-uniform luminance and color shift due to variations in light-scattering particle density and refractive index, leading to viewer discomfort and aesthetic issues.

Innovation Solution

A light guide panel design with a light-scattering layer having varying particle densities and uniform thickness, where the density of light-scattering particles increases with distance from the light source, combined with a matrix layer to maintain consistent luminance and minimize color shift.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If light-scattering particles are uniformly distributed in the light-scattering layer, then manufacturing is simple, but luminance uniformity deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidluminance uniformity
Core Design Contradiction:
Ease of manufactureVSIllumination intensity

Solution Approach 1:

The patent applies local quality by varying the density of light-scattering particles according to position. The light-scattering layer has a first region with higher particle density and a second region with lower particle density, where the density gradient is tailored to compensate for light intensity distribution, achieving uniform luminance across the display surface.

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If light-scattering particle density varies to improve luminance uniformity, then luminance uniformity improves, but color shift increases

Engineering Contradiction:
Improveluminance uniformityVSAvoidcolor shift
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent resolves the color shift issue by applying local quality in a controlled manner. While particle density varies between the first and second regions, the density variation is optimized to be minimal and localized, ensuring that the overall color consistency is maintained while still achieving the desired luminance uniformity through the density gradient.

Inventive Principle:
Principle #3Local quality

3Productivity

If light-scattering layer thickness varies to control light extraction, then light extraction efficiency improves, but manufacturing precision requirements increase

Engineering Contradiction:
Improvelight extraction efficiencyVSAvoidthickness control precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by controlling the thickness of the light-scattering layer in different regions. The first region has a greater thickness than the second region, creating a thickness gradient that optimizes light extraction efficiency. This parameter variation is integrated into the manufacturing process to achieve both high productivity and acceptable manufacturing precision.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The design achieves uniform luminance and minimizes color shift, providing a transparent lighting device with improved aesthetic appeal and functionality.

Implementation Method 1

a light-scattering layer provided on at least one of the top and bottom surfaces of the base substrate. The light-scattering layer includes a matrix forming a layer on the base substrate and light-scattering particles dispersed in the matrix

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

light may enter a base substrate of the LGP through a side surface of the base substrate and may travel within the base substrate while undergoing total reflection

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP4127561B1Light guide panel and lighting device including same
Publication Date: 2025.10.29 CORNING INC
  • EP4127561B1 patent drawingFigure 1~3
  • EP4127561B1 patent drawingFigure 4~6
  • EP4127561B1 patent drawingFigure 7~8

AI summary

Provided are a light guide panel and a lighting device including the same. The light guide panel includes a base substrate and a light-scattering layer provided on at least one of top and bottom surfaces of the base substrate with a matrix forming a layer on the base substrate and light-scattering particles dispersed in the matrix. A first portion of the light-scattering layer is distant from a light incident surface of the base substrate. A second portion of the light-scattering layer is located closer to the light incident surface than the first portion.