Image Sensor Selective Pixel Readout for Low-Noise Occupancy Detection

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Solution Overview

Problem

Existing image-based occupancy detection methods in lighting fixtures are complex and computationally expensive, requiring powerful processing circuitry that consumes additional power and increases costs.

Innovation Solution

An intelligent lighting fixture with an image sensor that selectively reads out a subset of pixels in an active pixel array, allowing for efficient occupancy detection by analyzing pixel data from a strategically chosen subset of pixels, reducing computational expense and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional image-based occupancy detection methods are used, then occupancy detection accuracy is achieved, but processing complexity and computational expense increase

Engineering Contradiction:
Improveoccupancy detection accuracyVSAvoidprocessing circuitry complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the image sensor's pixel array into multiple regions, with only selected regions being actively read out and processed. This segmentation approach allows the system to maintain occupancy detection accuracy by monitoring critical areas while reducing the overall processing complexity by excluding non-critical pixel regions from active processing.

Inventive Principle:
Principle #1Segmentation

2Reliability

If powerful processing circuitry is used to handle full image processing, then occupancy detection capability is improved, but power consumption increases

Engineering Contradiction:
Improveoccupancy detection capabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts and processes only the necessary pixel data from specific regions of the image sensor, rather than processing the entire image. This extraction approach maintains reliable occupancy detection by focusing computational resources on relevant areas while significantly reducing power consumption by avoiding processing of unnecessary pixel data.

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of information

If all pixels in the active pixel array are read out, then complete image data is obtained, but thermal noise and power consumption increase

Engineering Contradiction:
Improveimage data completenessVSAvoidthermal noise
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent applies different operational states to different regions of the pixel array, with selected regions being actively read out and other regions remaining inactive. This local quality approach ensures that sufficient image data is obtained from critical regions for accurate occupancy detection, while minimizing thermal noise by keeping non-critical regions in a low-power inactive state.

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

Enhances detection efficiency and accuracy while minimizing power consumption and thermal noise, enabling reliable occupancy detection with reduced processing resources.

Implementation Method 1

an image sensor 10 including an active pixel array 12

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP3841738B1Method and system for image based occupancy detection
Publication Date: 2025.09.03 CREE LIGHTING USA LLC
  • EP3841738B1 patent drawingFigure 1
  • EP3841738B1 patent drawingFigure 2
  • EP3841738B1 patent drawingFigure 3

AI summary

An image sensor includes an active pixel array including a number of pixels and image sensor control circuitry configured to perform a read operation only on a subset of the pixels of the active pixel array such that pixels not in the subset remain inactive. By reading out only the subset of pixels in the active pixel array and keeping the remaining pixels inactive, the temperature of the active pixel array may be reduced compared to a conventional read out process, thereby reducing thermal noise in the resulting pixel data.