Visible Light Sensor Glare Detection for Motorized Window Treatments

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing load control systems require complex configuration and advanced system controllers to accurately control motorized window treatments and prevent glare, often resulting in unnecessary and inaccurate control due to small, high-intensity glare sources.

Innovation Solution

A sensor, such as a visible light sensor, processes images to determine the position of a glare source and controls motorized window treatments to prevent glare, using techniques such as reducing image resolution, grouping pixels, and adjusting glare condition thresholds based on image resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional glare detection systems use high-resolution imaging to accurately detect glare sources, then measurement precision is improved, but device complexity and processing requirements increase

Engineering Contradiction:
Improveglare source detection accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the image processing task by dividing the window area into multiple zones and processing only relevant regions. The sensor array is divided into multiple sensors, each responsible for specific zones, reducing the computational burden on each individual component while maintaining overall detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by using reduced-resolution imaging for initial glare detection. Instead of processing the entire high-resolution image, the system uses lower resolution sensors that capture only the essential glare information, thereby reducing device complexity while maintaining sufficient measurement precision for glare prevention.

Inventive Principle:
Principle #16Partial or excessive action

2Reliability

If the system controls motorized window treatments based on all detected glare conditions, then glare prevention effectiveness is improved, but unnecessary control actions increase due to small high-intensity glare sources

Engineering Contradiction:
Improveglare prevention effectivenessVSAvoidunnecessary control actions
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies local quality by assigning different evaluation criteria to different glare sources based on their characteristics. Small high-intensity glare sources (like reflections) are evaluated differently from large glare sources (like direct sunlight). The system considers the position, size, and intensity of each glare source independently, allowing selective control actions only for glare sources that truly affect occupant comfort.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system uses feedback by continuously monitoring glare conditions and adjusting window treatment control decisions based on the actual impact on occupants. The control algorithm learns from past control actions and their effectiveness, reducing unnecessary adjustments while maintaining effective glare prevention.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If the system processes complete high-resolution images for glare detection, then measurement precision is improved, but processing time and energy consumption increase

Engineering Contradiction:
Improveglare source position accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the image processing task by dividing the window area into multiple zones and processing only relevant regions. The sensor array is divided into multiple sensors, each responsible for specific zones, reducing the computational burden on each individual component while maintaining overall detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by using reduced-resolution imaging for initial glare detection. Instead of processing the entire high-resolution image, the system uses lower resolution sensors that capture only the essential glare information, thereby reducing device complexity while maintaining sufficient measurement precision for glare prevention.

Inventive Principle:
Principle #16Partial or excessive action

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 effectively prevents glare by accurately determining the position and intensity of glare sources, reducing unnecessary control of motorized window treatments and improving the accuracy of glare prevention.

Implementation Method 1

A sensor, such as a visible light sensor, processes images to determine the position of a glare source

Methodology Applied
Scientific EffectVisible light detection: Photoelectric Effect

Data Source

PatentEP4502961A1Visible light sensor configured for glare detection and controlling motorized window treatments
Publication Date: 2025.02.05 LUTRON TECHNOLOGY COMPANY LLC
  • EP4502961A1 patent drawingFigure 1
  • EP4502961A1 patent drawingFigure 2
  • EP4502961A1 patent drawingFigure 3

AI summary

A sensor and/or system controller may process an image multiple times at multiple resolutions to detect glare conditions. A glare condition threshold used to determine whether a glare condition exists may be based on the resolution of the image. When the resolution of the image is higher, the glare condition threshold may be higher. The sensor and/or system controller may organize one or more adjacent pixels having similar intensities into pixel groups. The pixel groups may vary in size and/or shape. The sensor and/or system controller may determine a representative group luminance for the pixel group (e.g., an average luminance of the pixels in the group). The sensor and/or system controller may determine a group glare condition threshold, which may be used to determine whether a glare condition exists for the group of pixels and/or may be based on the size of the group.