Multi-Spectral Light Sensor Layout for Low Cross-Talk Color Measurement

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Solution Overview

Problem

High-cost color meters used for assessing electronic devices and light sources are not efficiently manufactured, necessitating a more cost-effective and efficient design for color measurement.

Innovation Solution

An optoelectronic device comprising a photodiode array, a guide array with light-blocking material, and a filter array with bandpass filters, allowing for energy measurement across various light spectra, including visible, IR, and UV bands, while reducing cross-talk between photodiodes through a light-blocking layer aligned with n-well regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional color meters are used for measuring color, then measurement accuracy is maintained, but manufacturing cost becomes prohibitively high

Engineering Contradiction:
Improvemanufacturing costVSAvoidcolor measurement accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The device segments the spectrum into multiple wavelength bands using a photodiode array with individual spectral responses. Each photodiode measures a specific portion of the spectrum, and the controller combines these segmented measurements to reconstruct the full spectral power distribution, enabling accurate color measurement without expensive traditional spectrometers

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The photodiode array serves multiple functions: each photodiode acts as both a detector and a spectral filter through its inherent spectral response characteristics. This multi-functional approach eliminates the need for separate filters and detectors for each wavelength band, significantly reducing manufacturing cost while maintaining measurement capability

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

2Device complexity

If photodiode array without light-blocking material is used, then device complexity is reduced, but cross-talk between photodiodes increases

Engineering Contradiction:
Improvestructure complexityVSAvoidmeasurement accuracy
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent extracts and removes stray light and cross-talk interference from the measurement path by positioning light-blocking material between adjacent photodiodes. This extraction of harmful light ensures that each photodiode measures only the light intended for it, improving measurement reliability without significantly increasing device complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The light-blocking material acts as an intermediary element between adjacent photodiodes, preventing direct optical coupling and cross-talk. This mediator ensures optical isolation while maintaining the compact array structure, balancing simplicity with measurement accuracy

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

The solution enables accurate and cost-effective measurement of light spectra, improving the accuracy of color assessment and reducing manufacturing costs by utilizing a multi-spectral light sensor with a guide array and filter array configuration.

Implementation Method 1

a filter array disposed over the guide array, the filter array including a plurality of bandpass filters, each bandpass filter being aligned with a different one of the plurality of guide members, each bandpass filter having a different transmission band

Methodology Applied
Scientific EffectBandpass filtering: Filter (optical)

Implementation Method 2

a photodiode array including a plurality of first photodiodes, each first photodiode including a respective n+ region and a respective n-well region

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3759742B1Multi-spectral light sensor
Publication Date: 2024.03.13 VISHAY INTERTECHNOLOGY INC
  • EP3759742B1 patent drawingFigure 1A
  • EP3759742B1 patent drawingFigure 1B~1C
  • EP3759742B1 patent drawingFigure 2

AI summary

An optoelectronic device is disclosed, comprising: a photodiode array including a plurality of first photodiodes, each first photodiode including a respective n+ region and a respective n-well region; a guide array disposed over the photodiode array, the guide array including a plurality of guide members separated from one another by a layer of light-blocking material, the guide members being aligned with the n+ regions of the first photodiodes, such that each guide member is disposed over a different respective n+ region, and the layer of light-blocking material being aligned with the n-well regions of the first photodiodes; and a filter array disposed over the guide array, the filter array including a plurality of bandpass filters, each bandpass filter being aligned with a different one of the plurality of guide members, each bandpass filter having a different transmission band.