Integrated Polarization Sensor Matrix for Illumination Gradient Errors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing polarization sensors are prone to errors due to uneven illumination conditions, particularly with nonlinear gradients, which cannot be easily distinguished from polarization information, leading to inaccurate measurements.

Innovation Solution

The arrangement of polarization-sensitive sensors with different orientations in a matrix structure, such as 8x8, 16x16, or 32x32, using lithographic methods to create grating structures and opaque walls to minimize sensitivity to local disturbances, ensuring accurate polarization measurement even under varying illumination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a simple arrangement of four polarization-sensitive sensors is used, then the device complexity is reduced, but measurement precision deteriorates due to erroneous signals from uneven illumination conditions

Engineering Contradiction:
Improvesensor arrangement complexityVSAvoidpolarization measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The sensor area is divided into multiple smaller sub-sensors arranged in a matrix (e.g., 8x8, 16x16, or 32x32), where each sub-sensor captures local polarization information. This segmentation allows the system to distinguish between polarization-induced signal variations and illumination non-uniformity by analyzing spatial patterns across the matrix, thereby maintaining low device complexity while improving measurement precision.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If surrounding brightness sensors are added to compensate for illumination gradients, then measurement precision improves, but device complexity increases

Engineering Contradiction:
Improvepolarization measurement accuracyVSAvoidsensor array complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The polarization-sensitive sensor matrix serves multiple functions simultaneously: it measures polarization angle, compensates for illumination non-uniformity, and provides spatial information. By using the same sensor elements for both polarization detection and illumination gradient compensation through differential signal analysis, the system achieves high measurement precision without adding separate brightness sensors, thus avoiding increased device complexity.

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

3Measurement precision

If the sensor area is divided into smaller sub-sensors, then measurement precision improves by reducing brightness gradient influence, but device complexity increases

Engineering Contradiction:
Improvepolarization measurement accuracyVSAvoidsensor matrix complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system transitions from a single-sensor approach to a two-dimensional matrix arrangement of sub-sensors. This dimensional change enables the system to capture spatial variation patterns across the sensor area, allowing differentiation between polarization-induced signals and illumination gradients through multi-point analysis. The matrix structure provides additional spatial dimension for error compensation while maintaining manageable device complexity through regular patterning.

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

This approach significantly reduces measurement errors caused by intensity fluctuations, achieving high accuracy and insensitivity to local disturbances, enabling precise polarization angle sensing.

Implementation Method 1

Polarization angle sensors have a major advantage over optical encoders because they are insensitive to mechanical tolerances and vibration due to the use of an unstructured polarizing filter as a rotary encoder

Methodology Applied
Scientific EffectPolarization: Polarisation

Implementation Method 2

The basic measuring principle, based on the penalty law, can be demonstrated using a single polarization-sensitive sensor

Methodology Applied
Scientific EffectMalus's Law:

Implementation Method 3

the polarization filter has grating structures produced by lithographic methods in at least one manufacturing plane

Methodology Applied
Scientific EffectDiffraction Grating: Diffraction Grating

Implementation Method 4

sensor elements, each of which is arranged as a structural unit in cooperation with a polarization filter to form one of the polarization-sensitive sensors

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP4394461B1Integrated circuit for measuring the polarization of light
Publication Date: 2025.07.16 POLDI MICROELECTRONICS GMBH
  • EP4394461B1 patent drawingFigure 1
  • EP4394461B1 patent drawingFigure 2
  • EP4394461B1 patent drawingFigure 3

AI summary

The invention relates to an integrated circuit for measuring the polarization of light with polarization-sensitive sensors having different orientations of the polarization planes as basic elements, preferably in four different orientations (1, 2, 3, 4), with sensor elements that are each arranged together with a polarization filter to form one of the polarization-sensitive sensors as a structural unit, wherein the polarization-sensitive filter of the polarization-sensitive sensor arranged as a structural unit has a targeted extent and orientation, wherein the polarization filter has grid structures produced by lithographic methods in at least one manufacturing plane, wherein the polarization-sensitive sensors of different orientations consist of a plurality of individual sensor elements arranged in a matrix, wherein the integrated circuit includes devices that are configuredto make a statement about the polarization of the incident light from the signals of the polarization-sensitive sensors, wherein the basic elements with different orientations (1,2,3,4) are arranged in an 8x8 matrix, wherein the basic elements in the first row of the 8x8 matrix are arranged [1,2,3,4,2,1,4,3], in the second row of the 8x8 matrix are arranged [4,3,2,1,3,4,1,2], in the third row of the 8x8 matrix are arranged [3,4,1,2,4,3,2,1], in the fourth row of the 8x8 matrix are arranged [2,1,4,3,1,2,3,4], in the fifth row of the 8x8 matrix are arranged [4,3,2,1,3,4,1,2], and in the sixth row of the 8x8 matrix are arranged [1,2,3,4,2,1,4,3], the seventh row of the 8x8 matrix has the arrangement [2,1,4,3,1,2,3,4] and the eighth row of the 8x8 matrix has the arrangement [3,4,1,2,4,3,2,1].