Movable Microlens Arrays for Directional Microdisplay Pixels

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Solution Overview

Problem

Current optoelectronic devices face challenges in achieving directional light emission and high luminous efficiency, leading to reduced resolution and increased power consumption, particularly in applications like virtual reality and three-dimensional imaging, due to the limitations of nanometric light-emitting diodes and static focusing mechanisms.

Innovation Solution

The optoelectronic device incorporates a configuration of primary and secondary pixels with optical systems that move relative to each other, allowing for dynamic adjustment of light focus and directionality, using piezoelectric or micro-actuators to ensure that light beams are collimated and directed efficiently, thereby enhancing the resolution and luminous efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If nanometric light-emitting diodes are used to increase screen definition, then the resolution is improved, but the light intensity emitted decreases drastically

Engineering Contradiction:
Improvescreen definitionVSAvoidlight intensity
Core Design Contradiction:
Measurement precisionVSIllumination intensity

Solution Approach 1:

The patent combines multiple light-emitting diodes (up to 100,000 LEDs) into a single sub-pixel structure. This merging of numerous nanometric LEDs within each sub-pixel collectively generates sufficient light intensity while maintaining the high resolution benefits of nanometric dimensions. The combined emission from all LEDs in a sub-pixel compensates for the low intensity of individual nanometric LEDs.

Inventive Principle:
Principle #5Merging (Combining)

2Illumination intensity

If three-dimensional wired light-emitting diodes are used, then the light emission capability is improved, but the light is not focused and emits in all directions

Engineering Contradiction:
Improvelight emission capabilityVSAvoiddirectional control
Core Design Contradiction:
Illumination intensityVSEase of operation

Solution Approach 1:

The patent introduces microlens arrays as intermediary optical elements positioned above the LED arrays. These microlenses act as mediators that capture the omnidirectional light from the LEDs and redirect it into focused, directional beams. The microlens array transforms the uncontrolled light emission into precisely directed light paths suitable for waveguide coupling and display applications.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the light emitted by micro displays is injected into waveguides, then the directional requirement is met, but the coupling efficiency requires highly directional light which is difficult to achieve

Engineering Contradiction:
Improvedirectional light requirementVSAvoidcoupling efficiency
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The microlens array serves as an intermediary optical system that bridges the gap between the omnidirectional LED emission and the directional requirements of waveguide coupling. By positioning microlenses directly above each LED or group of LEDs, the system efficiently couples light into the waveguide mode, minimizing energy loss and maximizing coupling efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Device complexity

If static focusing mechanisms are used, then the device structure is simplified, but ghost images appear and resolution is reduced

Engineering Contradiction:
Improvedevice structureVSAvoidresolution
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent employs dynamically adjustable focusing mechanisms, such as liquid crystal lenses or movable microlens arrays, that can change their optical properties in real-time. This dynamic capability allows the system to focus light precisely onto the waveguide or display surface, eliminating ghost images caused by static focusing limitations while maintaining high resolution. The dynamic adjustment enables adaptive optimization of the optical path.

Inventive Principle:
Principle #15Dynamics

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 configuration improves the resolution and luminous efficiency of the optoelectronic device, reduces power consumption, and eliminates ghost images, enabling high-quality three-dimensional imaging with reduced electrical usage.

Implementation Method 1

each optical system (Ci) being configured to act optically on all or part of the light beams likely to be emitted by the sub-pixels (Aiβ, Biβ) belonging to the pixels (Ai, Bi) that it covers

Methodology Applied
Scientific EffectOptical focusing: Focusing

Implementation Method 2

using piezoelectric or micro-actuators to ensure that light beams are collimated and directed efficiently

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3977725B1Optoelectronic device with optical systems movable over different pixels and control method
Publication Date: 2024.07.03 ALEDIA INC
  • EP3977725B1 patent drawingFigure 1
  • EP3977725B1 patent drawingFigure 2A~2F
  • EP3977725B1 patent drawingFigure 3~4

AI summary

Optoelectronic device (10) comprising: a set {Ai} of pixels (Ai) wherein each pixel (Ai) comprises a sub-pixel (Aiβ) capable of emitting a primary light beam, a set {Bi} of pixels (Bi), each pixel (Ai) being adjacent to a pixel (Bi) wherein each secondary pixel (Bi) comprises at least one secondary sub-pixel (Biβ) capable of emitting a secondary light beam, a set {Ci} of optical systems (Ci) arranged so as to be able to cover an entire pixel (Ai, Bi) belonging to one of the sets ({Ai}, {Bi}) and at least part of the sub-pixels (Aiβ, Biβ) of at least one of the adjacent pixels (Ai, Bi) belonging to the other set ({Ai}, {Bi}), the number of pixels (Ai, Bi) being greater than twice the number of optical systems (Ci), at least one movement mechanism (111) applying a relative movement between the set {Ci} and the sets ({Ai}, {Bi}) according to a predetermined sequence.