Micro LED Display Wavelength Conversion for Color Uniformity

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Solution Overview

Problem

Existing display apparatuses using micro LEDs face challenges in minimizing wavelength deviation of light emitted from pixels and micro LEDs, which affects color accuracy and uniformity.

Innovation Solution

The display apparatus incorporates a plurality of micro LEDs with light conversion layers and filters to adjust the wavelength of emitted light, minimizing deviations and enhancing color consistency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If micro LEDs are used in display apparatus, then high resolution and small pixel size are achieved, but wavelength deviation of emitted light increases

Engineering Contradiction:
Improvepixel sizeVSAvoidwavelength deviation
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

A wavelength adjustment layer is introduced as an intermediary component between the micro LED and the observer. This layer contains phosphors or fluorescent materials that absorb the broad-spectrum light from the micro LED and re-emit light at a more specific wavelength, thereby reducing wavelength deviation while maintaining the small pixel size advantage of micro LEDs

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the optical parameters of the display system by changing the wavelength characteristics of emitted light through the wavelength adjustment layer. By controlling the phosphor composition, particle size distribution, and layer thickness, the system transforms the broad wavelength spectrum from micro LEDs into a narrower, more controlled wavelength range

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If multiple micro LEDs are arranged in pixels, then high resolution display is achieved, but color uniformity across pixels deteriorates

Engineering Contradiction:
Improvepixel arrangementVSAvoidcolor uniformity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The wavelength adjustment layer is configured with spatially varying properties to compensate for local variations in micro LED characteristics. Different regions of the layer contain phosphors with different emission characteristics or varying concentrations, tailored to correct the specific wavelength deviations of micro LEDs in different locations, thereby achieving uniform color output across all pixels

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent applies parameter changes at the local level by varying the phosphor composition, particle size, or layer thickness in different regions of the wavelength adjustment layer. This localized parameter adjustment compensates for manufacturing variations in individual micro LEDs, ensuring consistent color output across the entire display

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

This solution effectively reduces wavelength deviation of light emitted from micro LEDs, improving color accuracy and uniformity in the display apparatus.

Implementation Method 1

Each of the plurality of pixels may include a micro light emitting diode and a wavelength conversion layer disposed on the micro light emitting diode. The wavelength conversion layer may convert light having a first wavelength emitted from the micro light emitting diode to light having a second wavelength

Methodology Applied
Scientific EffectWavelength conversion: Photoluminescence

Implementation Method 2

A filter layer may be disposed on the wavelength conversion layer. The filter layer may have a characteristic of blocking light having a third wavelength and transmitting light having a fourth wavelength

Methodology Applied
Scientific EffectOptical filtering: Filter (optical)

Data Source

PatentEP3703133B1Display apparatus
Publication Date: 2025.05.21 SAMSUNG ELECTRONICS CO LTD
  • EP3703133B1 patent drawingFigure 1
  • EP3703133B1 patent drawingFigure 2
  • EP3703133B1 patent drawingFigure 3

AI summary

A display apparatus includes a blue light emitting element configured to emit blue light; a red light emitting element configured to emit red light; and a green light emitting element configured to emit green light. The blue light emitting element may include a first light emitting diode configured to emit light having a maximum intensity at a wavelength shorter than a blue wavelength; and a blue filter configured to transmit light having the blue wavelength.