Polarization Filter Array for Image Sensor Calibration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current image processing technologies lack effective tools for analyzing and utilizing polarization properties of light, which limits the extraction of additional information from images and the calibration of image sensors and light sources.

Innovation Solution

A light polarization filter system comprising an array of polarization cells in various directions, integrated with a wavelength filter and image sensor, allows for the analysis of polarization properties of light, enabling enhanced image capture and processing, as well as calibration of image sensors and light sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If a segmented polarizer with multiple polarization cells is used to capture polarization information, then the amount of polarization information obtained is improved, but the device complexity and cost increase

Engineering Contradiction:
Improvepolarization informationVSAvoiddevice complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The imaging device divides the sensor array into multiple groups, with each group containing pixels of different colors (e.g., red, green, blue) that share the same polarization filter. This segmentation allows each pixel group to capture polarization information for its specific color channel, enabling polarization analysis without requiring separate sensors for each polarization angle, thus reducing overall device complexity while preserving polarization information.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each polarization filter is designed to serve multiple color channels simultaneously. A single polarization filter at a given angle is shared by multiple pixels with different color filters, allowing the same optical element to capture polarization information across multiple spectral bands. This multi-functionality reduces the total number of polarization filters needed, lowering device complexity and cost.

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

2Measurement precision

If polarization filters are added to the imaging system to capture polarization properties, then the measurement precision of light properties is improved, but the device complexity increases

Engineering Contradiction:
Improvemeasurement precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the polarization filtering function with the existing color filter array structure. Instead of adding separate polarization measurement devices, the polarization filters are integrated into the pixel groups that already exist in the sensor array. This merging approach enables polarization measurement precision improvement while utilizing the existing device architecture, thereby minimizing the increase in overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If multiple polarization cells with different angles are positioned for multiple pixels, then the polarization analysis capability is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvepolarization analysis capabilityVSAvoidease of manufacture
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent implements local quality by assigning specific polarization filter angles to specific pixel groups based on their color channels and spatial positions. Each pixel group has a tailored polarization filter configuration optimized for its function, while the overall pattern follows a regular, repeating structure. This local optimization maintains high polarization analysis capability while enabling standardized manufacturing through periodic repetition of the same sub-pattern across the sensor array.

Inventive Principle:
Principle #3Local quality

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 provides enhanced image capture with additional layers of information, enabling the deduction of object properties, detection of elements, and calibration of image sensors and light sources, improving image quality and accuracy.

Implementation Method 1

A light polarization filter system comprising an array of polarization cells in various directions

Methodology Applied
Scientific EffectPolarization: Polarisation

Data Source

PatentEP2539853B1Light filter with varying polarization angles and processing algorithm
Publication Date: 2019.01.09 LIRHOT SYST LTD
  • EP2539853B1 patent drawingFigure 1~2
  • EP2539853B1 patent drawingFigure 3~4
  • EP2539853B1 patent drawingFigure 5

AI summary

A method, system and polarization filter for analyzing polarization properties of light are described, the method comprising: receiving image data from a plurality of image sensor cells, the image sensor cells comprised in an image sensing system; separating from the received image data polarization information and scene image data of a scene being captured; and processing the polarization information to deduce information. Additionally, a polarization filter for analyzing polarization properties of light is described, the polarization filter comprising an array of polarization cells in various directions of polarization, the polarization filter comprising a core array of at least horizontal polarization filter cell, vertical polarization filter cell, no-polarization filter cell and circular polarization filter cell.