Low Inductance Light Source Module for TOF-3D Cameras

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

TOF-3D cameras face challenges in acquiring an acceptable range image due to insufficient reflected light, primarily because of limited light intensity from the light source, which is constrained by cost, heat dissipation, and the need for high-frequency, short-duration light pulses, leading to signal-to-noise ratio issues.

Innovation Solution

A light source module with a semiconductor light source and a low-inductance electrical connector that efficiently connects the light source to a power supply, allowing for effective energy use and heat dissipation, while maintaining a small footprint, thereby enhancing light intensity and reducing inductive losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If light source intensity is increased to improve reflected light signal, then signal-to-noise ratio is improved, but heat dissipation requirements and cost increase

Engineering Contradiction:
Improvelight intensityVSAvoidheat dissipation
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The electrical connection is segmented into multiple parallel conductive paths (multiple traces on the circuit board) rather than a single thick conductor. This segmentation reduces the inductance of each path while collectively handling the full current, enabling better high-frequency performance without requiring excessive current intensity that would generate harmful heat

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a conventional three-dimensional wire-based connection to a two-dimensional planar trace structure on the circuit board. This dimensional change allows for optimized current distribution and reduced inductance through careful trace routing, achieving low-inductance performance without the thermal management issues associated with high-current wire connections

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

2Productivity

If light pulse repetition frequency is increased to improve illumination coverage, then productivity is improved, but inductive voltage swings increase

Engineering Contradiction:
Improverepetition frequencyVSAvoidinductive voltage swings
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The electrical connection is segmented into multiple parallel conductive paths (multiple traces on the circuit board) rather than a single thick conductor. This segmentation reduces the inductance of each path while collectively handling the full current, enabling better high-frequency performance without excessive inductive voltage swings

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple low-inductance trace paths are merged in parallel to collectively carry the full drive current to the light source. This merging of multiple low-inductance paths achieves overall low inductance performance, enabling high repetition frequency operation with minimal inductive voltage swings and energy loss

Inventive Principle:
Principle #5Merging (Combining)

3Loss of energy

If conductor size is increased to reduce inductance, then inductive losses are reduced, but device footprint increases

Engineering Contradiction:
Improveinductive lossesVSAvoidfootprint
Core Design Contradiction:
Loss of energyVSArea of stationary object

Solution Approach 1:

The electrical connection is segmented into multiple parallel conductive paths (multiple traces on the circuit board) rather than a single thick conductor. This segmentation reduces the inductance of each path while collectively handling the full current, achieving low inductance without requiring a large single conductor that would increase footprint

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a three-dimensional wire-based connection to a two-dimensional planar trace structure on the circuit board. This dimensional change allows for optimized current distribution and reduced inductance through careful trace routing, achieving low-inductance performance with minimal footprint increase

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

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 improves the efficiency of energy use and heat dissipation, enabling the production of high-repetition-rate light pulses with improved signal-to-noise ratio, enhancing the capability of TOF-3D cameras to acquire range images with increased optical power and reduced electrical-to-optical conversion inefficiencies.

Implementation Method 1

The electrical connector provides conductors for electrically connecting the light source to a power supply

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

The closely spaced wide conductors configured to carry current in opposite directions provide the light source with a low inductance connection to the power supply

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

a semiconductor light source and a low inductance electrical connector that mechanically supports the light source

Methodology Applied
Scientific EffectLight emitting diode effect: Light Emitting Diode

Implementation Method 4

the light source may be operated to produce short light pulses at a high repetition rate

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 5

The wide conductors also provide thermally conductive channels for efficient dissipation of heat generated by operation of the light source

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2707646B1Low inductance light source module
Publication Date: 2016.09.28 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP2707646B1 patent drawingFigure 1A~1B
  • EP2707646B1 patent drawingFigure 1C~1D
  • EP2707646B1 patent drawingFigure 2

AI summary

An embodiment of the invention provides a low inductance light source module comprising a connector having a layer of insulating material sandwiched between first and second conducting layers and a semiconducting light source that seats in a recess extending through the first conducting layer and the insulating later and has first and second electrical contacts for receiving power electrically connected to the first and second conducting layers.