Depth-Sensitive Imager Using Polarization State Mapping

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing depth-sensitive imaging techniques face challenges in achieving adequate depth resolution due to the difficulty in resolving reflected illumination from objects against a background of ambient light, which can 'wash out' the signal.

Innovation Solution

A depth-sensitive imager that projects polarized illumination onto a scene and captures images using a detector configured to encode the polarization state of the reflected light, allowing the analyzer to distinguish between light from the illumination system and ambient light, thereby providing three-dimensional depth information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If intensity information of pulsed or structured illumination is analyzed to resolve depth, then depth resolution is achieved, but the ability to resolve reflected illumination against ambient light background deteriorates

Engineering Contradiction:

Improvedepth resolutionVSAvoidsignal resolution against ambient light

Core Design Contradiction:

Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent changes the detection parameter from intensity to polarization state. By analyzing the polarization state of reflected light rather than its intensity, the system can distinguish between polarized reflected illumination and unpolarized ambient light, resolving the signal resolution problem while maintaining depth resolution capabilities

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces polarization state as an intermediary characteristic to separate the signal from noise. The polarization state acts as a mediator that allows the system to distinguish reflected illumination from ambient light, enabling accurate depth measurement without being washed out by ambient light background

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enhances signal-to-noise ratio and enables effective distinction between light sources, improving depth resolution and accuracy in three-dimensional imaging applications.

Implementation Method 1

a light source configured to project a polarized illumination onto the surface

Methodology Applied

Scientific EffectPolarization: Polarisation

Implementation Method 2

the detected light includes a portion of the polarized illumination reflected from the surface

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS8264536B2Depth-sensitive imaging via polarization-state mapping

Publication Date: 2012.09.11 MICROSOFT TECHNOLOGY LICENSING LLC

AI summary

A depth-sensitive imager for imaging a scene in three dimensions. The depth-sensitive imager comprises a light source configured to project a polarized illumination onto a surface of the scene, and a detector configured to capture an image of the scene by detecting light from the scene, in which image a polarization state of the light is encoded. The detected light includes a portion of the polarized illumination reflected from the surface. The depth-sensitive imager further comprises an analyzer configured to generate output responsive to a distance between the light source and the surface based on the image.