VCSEL Light Projecting System with Switchable Diffuser

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Solution Overview

Problem

Current light projecting technologies are hindered by high costs, large size, and low integration, as they often require multiple light sources and projection systems to achieve desired functionalities, leading to inefficiencies and cumbersome modules, particularly in applications like 3D feature detection and mapping.

Innovation Solution

A light projecting system utilizing a vertical-cavity surface-emitting laser (VCSEL) element, diffraction optics, and a switchable diffuser with a polymer-liquid crystal mixture that can change its molecular orientation in response to voltage, allowing for time division multiplexed emission of flood light and collimated beams from a single light source, enabling efficient projection of both flood light and dot light patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple distinct light sources (flood light and dot projector) are used to achieve both flood light illumination and dot projection, then the desired 3D feature detection and mapping functions are achieved, but the device size becomes large and the structure becomes cumbersome

Engineering Contradiction:
Improvelight projection functionalityVSAvoidmodule size
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent combines flood light illumination and dot projection functions into a single light source by using a spatial light modulator to modulate the light from one VCSEL source, eliminating the need for separate flood light and dot projector components

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

A single VCSEL light source is made multi-functional by using a spatial light modulator to dynamically configure the light into different patterns (flood light or dot array) as needed, allowing one component to perform multiple functions that previously required separate components

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

2Adaptability or versatility

If multiple distinct light sources and projection subsystems are deployed, then both flood light illumination and dot projection are achieved, but the system cost increases

Engineering Contradiction:
Improvelight projection capabilityVSAvoidsystem cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent merges multiple light projection subsystems into a single integrated system using one VCSEL source and one spatial light modulator, reducing the total component count and associated manufacturing costs

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single light source system with spatial light modulator provides universal light projection capability for both flood light and dot array patterns, eliminating the need to manufacture and assemble multiple specialized components

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

3Adaptability or versatility

If multiple light sources are used to achieve flood light and dot projection, then the desired projection functions are achieved, but the integration level remains low

Engineering Contradiction:
Improveprojection functionVSAvoidintegration level
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges multiple projection functions into a single integrated module where the VCSEL source and spatial light modulator work together as one unified system, significantly improving integration compared to separate flood light and dot projector assemblies

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

This solution reduces the need for multiple light sources and projection systems, resulting in a more compact, cost-effective, and integrated light projecting system capable of achieving 3D feature detection and mapping with improved efficiency and adaptability.

Implementation Method 1

the waveguide is configured to guide an in-coupled light beam to undergo total internal reflection between the surface A and the surface B

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

the grating structures are configured to disrupt the total internal reflection to cause at least a portion of the in-coupled light beam to couple out of the waveguide from the surface A

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 3

a switchable diffuser with a polymer-liquid crystal mixture that can change its molecular orientation in response to voltage

Methodology Applied
Scientific EffectLiquid crystals: Liquid Crystals

Data Source

PatentEP3916480B1Light projection system
Publication Date: 2023.04.19 SHENZHEN GUANGJIAN TECH CO LTD
  • EP3916480B1 patent drawingFigure 1
  • EP3916480B1 patent drawingFigure 2
  • EP3916480B1 patent drawingFigure 3A

AI summary

A system including: a light source, a switchable diffuser, a structured light detector, and a ToF detector. The light source and switchable diffuser are controlled to operate in concert (together, and/or with other optical and electrical elements of the system) to project pulses of collimated beams of light (interleaved between pulses of flood light) during a signle image capture period, the pulses of collimated beams of light being resolvable by the structured light detector and the ToF detector within the same image capture period.