Distance Measuring Apparatus Using Fringe Scanning and Segmentation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing distance measuring apparatuses struggle to accurately generate distance information for photographic subjects due to the influence of backgrounds, particularly when using gesture recognition techniques in head-mounted video display systems.

Innovation Solution

A distance measuring apparatus is integrated into a head-mounted video display system, utilizing a fringe scanning processor and image processor to generate distance information by modulating light with a pattern substrate and using correlation or moire developing methods to reduce noise and enhance accuracy, even in the presence of backgrounds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a special diffraction grating substrate is attached to an image sensor for distance measurement, then distance information can be generated from contrast and focus position, but background influence causes inaccurate distance measurement

Engineering Contradiction:

Improvedistance measurement accuracyVSAvoidbackground influence

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The image is divided into multiple regions, and distance information is calculated separately for each region. The processor identifies regions with high contrast (photographic subjects) and regions with low contrast (backgrounds), then processes distance calculation only for relevant regions, eliminating background interference.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different processing methods are applied to different regions of the image based on their local characteristics. Regions containing photographic subjects receive full distance measurement processing, while background regions are excluded or processed differently to prevent their influence on the final distance information.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If a head mounted video display apparatus is used for work support, then gesture recognition can be implemented, but the apparatus becomes heavy and creates load on the wearer

Engineering Contradiction:

Improvegesture operation capabilityVSAvoidwearer load

Core Design Contradiction:

Ease of operationVSWeight of moving object

Solution Approach 1:

The patent replaces traditional mechanical input devices with gesture-based input using the imaging device. By capturing images and analyzing hand gestures through image processing, the system eliminates the need for physical controllers or buttons, reducing the mechanical components and overall weight of the head-mounted apparatus.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If three-dimensional recognition technique using range image is used for target object recognition, then gesture recognition accuracy is improved, but the distance measuring apparatus becomes large and heavy

Engineering Contradiction:

Improvetarget object recognition accuracyVSAvoidapparatus weight

Core Design Contradiction:

Measurement precisionVSWeight of moving object

Solution Approach 1:

The patent extracts only the essential depth information needed for gesture recognition from the imaging data, rather than using full three-dimensional range imaging. By calculating distance based on focus position and contrast in two-dimensional images, the system achieves sufficient recognition accuracy without the complexity and weight of complete 3D recognition systems.

Inventive Principle:

Principle #2Taking out (Extraction)

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 allows for the generation of highly accurate distance information for photographic subjects, reducing the impact of backgrounds and improving gesture recognition in head-mounted video display systems.

Implementation Method 1

a method of measuring a distance to a target object by attaching a special diffraction grating substrate to an image sensor and using a projection pattern generated on the image sensor by light transmitted through diffraction grating substrate

Methodology Applied

Scientific EffectDiffraction grating: Diffraction Grating

Implementation Method 2

using correlation or moire developing methods to reduce noise and enhance accuracy

Methodology Applied

Scientific EffectMoiré effect: Moiré Effect

Data Source

PatentUS11740468B2Distance measuring apparatus, imaging device, distance measuring system, distance measuring method, and imaging method

Publication Date: 2023.08.29 MAXELL LTD

AI summary

An interframe difference processor 206 generates a difference image between frames of a sensor image, and an image processor 208 generates distance information indicating a distance to a photographic subject on the basis of calculation of a difference image and a developing pattern 1101. Thus, since a video display apparatus 101 generates the difference image between the frames of the sensor image, it is possible to realize a distance measuring apparatus capable of reducing an influence of a background and generating distance information with high accuracy.