Louvre Light Control Layer for Sunlight Glare in Displays

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Solution Overview

Problem

Optical components in display systems, such as waveguide pupil expanders, can cause sunlight glare by reflecting sunlight onto the viewing window, which can reduce image quality and visibility.

Innovation Solution

A light control layer with a louvre structure is integrated into the optical component to absorb or attenuate sunlight reflections while allowing image light to pass through, using louvres with specific orientations and materials to minimize glare without distorting the image.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a reflective surface is used in the optical component, then image light can be effectively directed to the viewing area, but sunlight glare is reflected onto the viewing area causing discomfort and reducing image quality

Engineering Contradiction:
Improveimage light intensityVSAvoidsunlight glare
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

A light control layer is introduced as an intermediary component between the reflective surface and the incoming sunlight. This layer contains a louvre structure that selectively blocks sunlight while allowing image light to pass through, thereby mediating the interaction between light and the optical component without compromising the reflective function

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The light control layer is applied selectively to specific regions of the optical component where sunlight glare is most problematic. The louvre structure provides localized glare reduction in these critical areas while maintaining the overall reflective performance of the optical component in other regions

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If a light control layer with louvre structure is added to block sunlight, then glare is reduced, but the structure may occlude or block image light paths

Engineering Contradiction:
Improvesunlight glareVSAvoidimage light transmission
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The louvre structure is designed with specific geometric dimensions and spacing relationships. The pitch between adjacent louvres and the depth of each louvre are carefully controlled to create channels that allow image light to pass through while blocking sunlight from reaching the reflective surface

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

3Object-affected harmful factors

If the pitch between adjacent louvres is reduced to block more sunlight, then glare reduction is improved, but the number of louvres increases making manufacturing more complex

Engineering Contradiction:
Improvesunlight glareVSAvoidlouvre structure fabrication
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The design optimizes key parameters of the louvre structure including pitch, depth, width, and orientation angle to achieve effective glare reduction with a manageable number of louvres. By carefully selecting these parameters, the design balances optical performance with manufacturing feasibility

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 light control layer effectively reduces sunlight glare while maintaining the quality of holographic images by absorbing or diffusing sunlight reflections, ensuring clear visibility in bright conditions.

Implementation Method 1

The light control layer comprises a louvre structure having an array of louvres... to absorb or attenuate sunlight... reducing luminance by up to 1,000,000 times for direct glare and 500,000 times for veiling glare

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Implementation Method 2

an optical component having a reflective surface... sunlight is incident on the reflective surface... it can reflect sunlight onto an optical path

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4332660B1Display system and light control element therefor
Publication Date: 2026.05.20 ENVISICS LTD
  • EP4332660B1 patent drawingFigure 1
  • EP4332660B1 patent drawingFigure 2
  • EP4332660B1 patent drawingFigure 3

AI summary

A display system and light control layer is described. The display system comprises an optical component having a reflective surface. A light control layer is disposed on a first surface of the optical component on an optical path of sunlight to the reflective surface. The light control layer comprises a louvre structure comprising an array of louvres. Each louvre is arranged at an orientation angle relative to the first surface. The separation between adjacent/neighbouring louvres is such that the distal end/edge of one louvre overlaps the proximal end/edge of the adjacent/neighbouring louvre.