Micro-LED Catadioptric Display for High-Contrast Ambient Light

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Solution Overview

Problem

Existing display technologies face challenges in achieving high contrast and efficiency in brightly illuminated environments due to ambient light reflections, which degrade image contrast and increase power consumption, especially in outdoor and indoor settings where stray light affects the display's performance.

Innovation Solution

A display apparatus comprising a plurality of micro-LEDs aligned with catadioptric optical elements and a low reflection screen, which minimizes reflections and provides high uniformity, efficiency, and dynamic range by using a light absorbing structure with a microstructured surface and acoustic apertures, allowing for scalable and cost-effective large-area displays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If an AR (anti reflection coating) layer is provided to reduce reflected luminance, then image contrast is improved, but manufacturing cost increases and the coating is susceptible to damage

Engineering Contradiction:
Improveimage contrastVSAvoidmanufacturing cost
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The display surface is segmented into multiple layers: a transparent substrate, a light absorbing structure with microstructured surface, and light transmitting apertures. This segmentation allows each layer to perform its specific function - the microstructured surface absorbs stray light while the apertures transmit display light, achieving contrast improvement without expensive AR coatings

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The light absorbing structure converts harmful reflected ambient light into beneficial absorbed energy. The microstructured surface with low reflectivity absorbs stray light that would otherwise degrade image contrast, transforming the harmful reflection effect into a benefit for improving display quality

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Illumination intensity

If packaged LED chips are used with black plastic resin to suppress background light reflections, then contrast is improved, but light absorption increases and power consumption rises

Engineering Contradiction:
ImprovecontrastVSAvoidpower consumption
Core Design Contradiction:
Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The light absorbing structure employs a porous or microstructured surface that provides high light absorption capability. This microstructured surface absorbs stray light effectively while maintaining low absorption of the display light passing through the apertures, improving contrast without excessive power consumption

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The solution moves from a two-dimensional planar black matrix to a three-dimensional microstructured light absorbing surface. This dimensional change allows the structure to absorb light from multiple angles and directions, providing superior contrast performance with better light management efficiency

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

3Manufacturing precision

If micro-LEDs with dimensions less than 100 microns are used to provide high resolution displays, then manufacturing precision is improved, but alignment complexity increases

Engineering Contradiction:
Improvedisplay resolutionVSAvoidalignment complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The micro-LED array, catadioptric optical elements, and light transmitting apertures are merged into a single integrated display apparatus. This merging reduces the number of separate components that need alignment, simplifying the manufacturing process while maintaining high resolution through the micro-LED technology

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 achieves high contrast ratios and reduced power consumption by minimizing reflections and optimizing light distribution, enabling high-resolution, high-luminance displays with improved image fidelity and efficiency in various ambient conditions.

Implementation Method 1

catadioptric optical elements

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

catadioptric optical elements

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

light absorbing structure with a microstructured surface

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

Data Source

PatentEP3704740B1Display apparatus
Publication Date: 2023.09.27 OPTOVATE
  • EP3704740B1 patent drawingFigure 1
  • EP3704740B1 patent drawingFigure 2
  • EP3704740B1 patent drawingFigure 3

AI summary

A display apparatus comprises an array of micro-LEDs and an aligned array of catadioptric optical elements wherein the array of micro optics is further aligned to an array of apertures of a low reflection screen. Advantageously such an arrangement provides a display with large images of configurable size, low cost and high brightness that can achieve high contrast in high illuminance from ambient lighting while also achieving high luminous efficiency.