Rearview Camera Glare Sensing for Variable Transmittance Mirrors

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Solution Overview

Problem

Existing variable transmittance mirror systems in vehicles require multiple devices, including a dedicated glare sensor, which increases costs and obstructs the user's view, and fail to optimally adjust transmittance for glare from varying light sources positioned differently across multiple mirrors.

Innovation Solution

A system comprising a rearview imager with a pixel array and a controller that captures image data to determine glare light intensity and adjust the transmittance of variable transmittance mirrors independently, eliminating the need for a dedicated glare sensor and allowing for optimal transmittance adjustment based on detected glare light positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a dedicated glare sensor is used to detect rearward light intensity, then the accuracy of glare detection is improved, but the number of devices increases and costs increase

Engineering Contradiction:
Improveglare detection accuracyVSAvoidnumber of devices
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The rearview camera's pixel array is made multi-functional by using it both for capturing rearward images and for detecting glare light intensity. The controller processes the pixel data to determine both image content and light intensity levels, eliminating the need for a separate dedicated glare sensor while maintaining detection accuracy.

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

Solution Approach 2:

The functions of the rearview camera and the glare sensor are merged into a single device. The same pixel array that captures images is also used to measure light intensity by analyzing the brightness values of pixels, thereby reducing the total number of components in the system.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If a dedicated glare sensor is positioned near the mirror, then the glare detection is accurate, but it obstructs the user's field of view

Engineering Contradiction:
Improveglare detection accuracyVSAvoidfield of view obstruction
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The glare sensing function is extracted from the physical sensor component and integrated into the camera system's software processing. By using the existing camera housing and lens assembly rather than adding a separate sensor near the mirror, the obstruction of the user's field of view is eliminated while maintaining the ability to accurately detect glare.

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If all mirrors are varied equally based on single light sensor data, then the control system is simple, but the transmittance adjustment is not optimal for mirrors with different glare exposure

Engineering Contradiction:
Improvecontrol system simplicityVSAvoidtransmittance optimization
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

Each mirror's transmittance is independently adjusted based on local glare conditions detected by the pixel array. The controller analyzes the position and intensity of glare sources relative to each mirror's orientation and adjusts transmittance accordingly, allowing each mirror to have optimized local properties rather than uniform adjustment.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The control system is segmented to independently control each mirror based on its specific glare exposure. Instead of a single unified control signal, the controller processes pixel data to determine individual glare conditions for each mirror and generates separate control signals, enabling adaptive optimization for each mirror position.

Inventive Principle:
Principle #1Segmentation

4Adaptability or versatility

If multiple devices are used including dedicated glare sensor and back-up camera, then the functionality is complete, but the overall cost increases

Engineering Contradiction:
Improvesystem functionalityVSAvoidoverall system cost
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The rearview camera is designed with multi-functionality to serve both as a backup camera for safety and as a glare sensor for mirror control. By making the camera perform dual functions through software processing of pixel data, the system maintains complete functionality while reducing component count and overall cost.

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

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 solution reduces the number of devices needed, lowers costs, and provides a cleaner, aesthetically appealing design while optimizing transmittance adjustments for glare reduction across multiple mirrors.

Implementation Method 1

The first imager comprises a pixel array and is configured to capture image data... assign a first light intensity value to one or more pixels based at least in part on the captured image data

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

The first variable transmittance mirror has a first level of transmittance... change the first level of transmittance to a second level of transmittance

Methodology Applied
Scientific EffectElectrochromism: Electrochromism

Data Source

PatentEP3887204B1System for rearview camera as a glare sensor
Publication Date: 2023.08.23 GENTEX CORP
  • EP3887204B1 patent drawingFigure 1
  • EP3887204B1 patent drawingFigure 2
  • EP3887204B1 patent drawingFigure 3

AI summary

A system for variable transmittance mirrors is disclosed wherein the variable transmittance mirrors may be controlled in response to images captured from a camera. The system may comprise a first imager, a first variable transmittance mirror, and a controller. The first imager comprises a pixel array. Further, the first imager is configured to capture image data. The first variable transmittance mirror has a first level of transmittance. Finally, the controller is configured to assign a first light intensity value to one or more pixels and change the first level of transmittance to a second level of transmittance based at least in part on the detected first light intensity. Such as system has the advantage of eliminating the need for a dedicated glare sensor, therefore reducing the number of devices, the costs, obstructions in a user's filed of view, and a more aesthetically appealing appearance.