VCSEL Arrays for Laser Display Scintillation Reduction

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Solution Overview

Problem

Current laser display technologies are inefficient, bulky, and produce dim or non-scalable results due to reliance on mechanical mirrors and analog power sources, leading to scintillation effects and high energy consumption, with limited capabilities in producing high-resolution color intensity profiles.

Innovation Solution

The use of vertically-emitting semiconductor laser (VCSEL) arrays, controlled by binary strings to define output intensities, which are combined to form colors without coherent interference, reducing scintillation and energy consumption, and enabling smaller, more efficient imaging systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If mechanical mirrors and analog power sources are used for laser display, then color intensity profiles can be produced, but the system becomes bulky, inefficient, and produces scintillation effects

Engineering Contradiction:
Improvecolor intensity profileVSAvoidsystem bulkiness
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical mirrors with electronically controlled VCSEL arrays that can be directly addressed by binary strings. This substitution eliminates the need for mechanical scanning components while maintaining the ability to produce color intensity profiles through digital control of individual laser elements.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transitions from analog power source variation to digital binary string control of VCSEL arrays. By changing the control parameter from continuous analog signals to discrete digital addresses, the system achieves both reduced complexity and elimination of scintillation effects while maintaining color intensity production capability.

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If mechanical mirrors and scanning apparatuses are used, then laser beam color intensity can be controlled, but energy consumption increases and scintillation effects occur

Engineering Contradiction:
Improvelaser beam color intensityVSAvoidenergy consumption
Core Design Contradiction:
Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The patent replaces mechanical scanning mirrors with a statically arrayed VCSEL configuration that uses electronic addressing. This eliminates the mechanical motion required for beam scanning while maintaining color intensity control through digital selection of active laser elements, thereby reducing energy consumption.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs binary string addressing that selectively activates specific VCSEL elements in a systematic sequence. This digital addressing method replaces continuous mechanical scanning with discrete, periodic activation of laser elements, reducing overall energy consumption while maintaining intensity control.

Inventive Principle:
Principle #19Periodic action

3Power

If coherent laser output is used, then intense color beams can be produced, but scintillation effects increase on the screen

Engineering Contradiction:
Improvebeam intensityVSAvoidscintillation effects
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent divides the laser output into multiple independent VCSEL elements arranged in an array. Each element can be independently addressed and controlled, allowing the system to produce intense color beams while reducing scintillation effects through the distributed nature of the segmented light sources.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the coherence parameter of the laser output by using multiple independently addressed VCSEL elements. This parameter change from coherent to partially incoherent output reduces scintillation effects on the screen while maintaining sufficient beam intensity for display applications.

Inventive Principle:
Principle #35Parameter changes

4Device complexity

If VCSEL arrays are used with binary string control, then system size and energy consumption are reduced, but manufacturing complexity increases

Engineering Contradiction:
Improvesystem sizeVSAvoidmanufacturing complexity
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

The patent employs a universal binary string addressing scheme that can control VCSEL arrays of various sizes and configurations. This multi-functional control approach simplifies the manufacturing process by using a single control methodology across different device variants, reducing overall manufacturing complexity despite the reduced system size.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent replaces complex mechanical control systems with integrated electronic addressing circuits that are fabricated alongside the VCSEL arrays using standard semiconductor manufacturing processes. This integration reduces system size while maintaining ease of manufacture through conventional fabrication techniques.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 approach results in brighter, high-bandwidth images with reduced scintillation and energy usage, allowing for more compact and cost-effective display systems that can produce accurate color intensity profiles efficiently.

Implementation Method 1

The vertical-cavity surface-emitting laser (VCSEL) is a type of semiconductor laser diode with laser beam emission perpendicular from the top surface

Methodology Applied
Scientific EffectLaser emission: Laser

Implementation Method 2

optical elements, such as non-linear crystals, can be used for doubling the frequency of the light and for allowing colored light output

Methodology Applied
Scientific EffectFrequency doubling: Second Harmonic Generation

Implementation Method 3

The output intensities from laser arrays are combined to form a single color or wavelength... Non-coherent output is desirable in this application as it reduces scintillation effects

Methodology Applied
Scientific EffectNon-coherent light combination:

Data Source

PatentEP2517321B1System for combining laser arrays for digital outputs
Publication Date: 2021.04.14 LUMENTUM OPERATIONS LLC
  • EP2517321B1 patent drawingFigure 1~2
  • EP2517321B1 patent drawingFigure 3
  • EP2517321B1 patent drawingFigure 4

AI summary

Embodiments comprise a device that can efficiently produce a highly resolved intensity profile that can be easily switched to various specific configurations with binary word strings defining output intensities that after summation will be combined to form a single colors intensity depth. Arraying these devices allows an image line of single color pixels to be efficiently produced without gross scintillation effects. The non-coherent output is desirable in this application as it reduces scintillation effects on the screen or final image.