ToF Sensor Structured Light Illuminator Depth Resolution

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Solution Overview

Problem

Time-of-Flight (ToF) sensors provide low-resolution depth information and are prone to artifacts like 'blooming' and inaccurate measurements when imaging highly reflective or absorptive materials, while traditional imaging sensors lack independent depth information.

Innovation Solution

A hybrid sensor system combining ToF sensors and structured light, where structured light patterns are used to enhance depth mapping accuracy, incorporating a controller to synchronize light sources and sensors for improved depth and image data fusion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If ToF sensors are used to obtain depth information, then depth measurement capability is provided, but resolution is low and blooming artifacts occur

Engineering Contradiction:

Improvedepth measurement accuracyVSAvoiddepth information resolution

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent segments the illumination function by introducing a separate structured light projector that divides the scene into multiple illuminated regions with distinct patterns. This allows the ToF sensor to capture depth information from different spatial segments simultaneously, improving both resolution and reducing blooming effects by localizing the measurement to specific patterned regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces structured light patterns as an intermediary between the light source and the scene. These patterns act as a mediator that encodes spatial information into the reflected light, enabling the ToF sensor to distinguish between different regions and improve depth measurement precision while reducing blooming artifacts through pattern-based localization.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If ToF sensors image highly reflective materials, then depth information is obtained, but blooming artifacts and inaccurate measurements occur

Engineering Contradiction:

Improvedepth measurement accuracyVSAvoidblooming effects

Core Design Contradiction:

Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by using structured light patterns that illuminate different regions with distinct spatial codes. Highly reflective materials reflect these localized patterns back to the sensor, allowing the system to distinguish between adjacent regions even when blooming occurs. The patterned illumination creates local quality variations that help identify and correct blooming artifacts in specific regions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system uses feedback by comparing the received structured light patterns with the expected patterns. When blooming occurs from highly reflective materials, the pattern distortion provides feedback that allows the system to identify and correct inaccurate depth measurements by analyzing how the known patterns have been distorted by the reflective surfaces.

Inventive Principle:

Principle #23Feedback

3Loss of information

If traditional imaging sensors are used, then image data is obtained, but independent depth information is lacking

Engineering Contradiction:

Improvedepth informationVSAvoidinformation completeness

Core Design Contradiction:

Loss of informationVSProductivity

Solution Approach 1:

The patent merges two previously separate systems - traditional imaging sensors and ToF depth sensors - into a unified system that uses structured light patterns. The imaging sensor captures the patterned light reflected from the scene, and by combining this with the known pattern structure, the system simultaneously obtains both high-quality images and accurate depth information, eliminating the need for separate sensors and improving overall information completeness.

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

The system achieves more accurate and higher-resolution depth information, reducing blooming effects and improving depth measurement reliability in diverse scenes, enabling better object detection and navigation capabilities.

Implementation Method 1

Time-of-Flight (ToF) sensors typically provide low-resolution depth information about a scene

Methodology Applied

Scientific EffectTime of flight: Time of Flight

Implementation Method 2

at least one light source configured to emit a structured light pattern

Methodology Applied

Scientific EffectLight emission: Light

Data Source

PatentUS20220276384A1Time-of-Flight Sensor with Structured Light Illuminator

Publication Date: 2022.09.01 WAYMO LLC

AI summary

The present disclosure relates to systems and methods that provide information about a scene based on a time-of-flight (ToF) sensor and a structured light pattern. In an example embodiment, a sensor system could include at least one ToF sensor configured to receive light from a scene. The sensor system could also include at least one light source configured to emit a structured light pattern and a controller that carries out operations. The operations include causing the at least one light source to illuminate at least a portion of the scene with the structured light pattern and causing the at least one ToF sensor to provide information indicative of a depth map of the scene based on the structured light pattern.