Laminated Light Guide Plates for Thin High-Contrast Backlighting

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing edge-type light-emitting units for displays and lighting applications lack the ability to achieve improved image resolution, dynamic range of chromaticity, and luminosity, limiting their display and illumination performance.

Innovation Solution

A laminated structure of two light guide plates with different light-guiding directions, combined with selective control of light-emitting sections, allows for independent luminance control of regions in the light-emitting surface, enhancing contrast and uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If an edge-type light-emitting unit is used to reduce thickness, then the device thickness is reduced, but the display quality and luminance distribution are insufficient

Engineering Contradiction:
Improvedevice thicknessVSAvoiddisplay quality
Core Design Contradiction:
Length of stationary objectVSManufacturing precision

Solution Approach 1:

The light guide plate is divided into multiple light guide regions with different light-guiding directions, allowing each region to independently control luminance distribution. This segmentation enables precise control of light propagation paths while maintaining the thin edge-type structure, resolving the contradiction between thickness reduction and display quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the light guide plate are assigned different optical properties and light-guiding directions tailored to specific display requirements. By optimizing each region's characteristics locally, the invention achieves superior overall display quality while maintaining the thin profile of the edge-type design.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If a direct-type light-emitting unit is used to improve display quality, then display quality is improved, but the device thickness increases

Engineering Contradiction:
Improvedisplay qualityVSAvoiddevice thickness
Core Design Contradiction:
Manufacturing precisionVSLength of stationary object

Solution Approach 1:

The invention transitions from the conventional planar light guide structure to a multi-directional three-dimensional light guiding system. By introducing light guide regions with different propagation directions in the thickness dimension, the invention achieves direct-type display quality while maintaining the thin edge-type form factor.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Manufacturing precision

If the light guide plate is divided into multiple light guide regions with different light-guiding directions, then luminance distribution is improved, but the device structure becomes more complex

Engineering Contradiction:
Improveluminance distributionVSAvoiddevice structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Multiple light guide regions with different light-guiding directions are integrated into a single light guide plate structure. This merging approach achieves improved luminance distribution through multi-directional light guiding while avoiding the complexity of multiple separate components, as all regions are formed within one integrated plate.

Inventive Principle:
Principle #5Merging (Combining)

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 solution enables superior image expression in displays and more uniform illumination in lighting applications by improving the contrast ratio and luminance distribution, achieving enhanced display and lighting performance.

Implementation Method 1

a first light guide plate that guides first light from a plurality of first light-emitting sections to propagate in a second direction different from a first direction in which the plurality of first light-emitting sections emit the first light, to output the first light from a first front surface

Methodology Applied
Scientific EffectLight guidance: Waveguide (optics)

Data Source

PatentEP3366976B1Light-emission device, display device, and illumination device
Publication Date: 2026.02.11 SONY GROUP CORP
  • EP3366976B1 patent drawingFigure 1A
  • EP3366976B1 patent drawingFigure 1B
  • EP3366976B1 patent drawingFigure 1C~1E

AI summary

A light-emitting unit that is thin but has superior light-emitting performance is provided. The light-emitting unit includes a plurality of first light-emitting sections, a first light guide plate, a plurality of second light-emitting sections, and a second light guide plate. The plurality of first light-emitting sections line up in a first direction, and emit first light individually. The first light guide plate includes a first end surface and a first front surface. The first light guide plate guides, along a second direction, a portion of the first light incoming from the first end surface, and outputs the guided portion of the first light from the first front surface. The first end surface extends along the first direction and faces the first light-emitting sections. The second direction is a direction getting away from the first end surface. The plurality of second light-emitting sections line up in a second direction, and emit second light individually. The second light guide plate includes a second end surface and a second front surface. The second light guide plate guides, along the first direction, a portion of the second light incoming from the second end surface, and outputs the guided portion of the second light from the second front surface. The second end surface extends along the second direction and faces the second light-emitting sections. The first light guide plate and the second light guide plate are laminated to cause the first front surface and the second front surface to be overlapped with each other.