Vehicle Rearview Camera Integration Time Control

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Solution Overview

Problem

Existing rearview display systems for vehicles face challenges in adjusting camera system sensitivity to varying ambient and glare conditions, leading to image saturation and suboptimal visibility, especially when exposed to bright headlights at night.

Innovation Solution

A display system that includes a processing system configured to receive inputs from both an ambient light sensor and a direct glare sensor to adjust the integration time of the camera system, allowing it to switch between day and night modes and prevent image saturation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the camera system uses a fixed integration time, then the device complexity is reduced, but the image quality deteriorates under varying light conditions (image saturation in bright conditions, poor visibility in dark conditions)

Engineering Contradiction:
Improveimage qualityVSAvoidcamera system control
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system employs light sensors that continuously monitor ambient light levels and feed this information back to the processing system, which then adjusts the camera integration time accordingly. This closed-loop feedback mechanism enables the camera to adapt to varying light conditions automatically, maintaining optimal image quality without requiring complex manual intervention or overly complicated hardware architecture.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The integration time of the camera system is made dynamic rather than fixed, allowing it to change in response to environmental conditions. The processing system dynamically adjusts the integration time based on real-time light sensor inputs, enabling the camera to optimize its performance for both bright daytime conditions and dark nighttime conditions, thereby resolving the contradiction between fixed simplicity and adaptive quality.

Inventive Principle:
Principle #15Dynamics

2Illumination intensity

If the camera system increases sensitivity to capture dark scenes, then visibility in dark conditions improves, but image saturation occurs in bright conditions (especially from headlights)

Engineering Contradiction:
Improvevisibility in dark conditionsVSAvoidimage saturation
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The camera system's sensitivity (integration time) is made dynamically adjustable based on ambient light conditions. In dark conditions, the integration time is increased to capture more light and improve visibility. In bright conditions, particularly when headlights are detected, the integration time is reduced to prevent image saturation. This dynamic adjustment resolves the contradiction between needing high sensitivity for dark scenes and avoiding saturation in bright scenes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the integration time parameter of the camera based on environmental light conditions. By monitoring ambient light levels and adjusting the integration time parameter accordingly, the system achieves high sensitivity when needed (dark conditions) while preventing saturation when light levels are high (bright conditions with headlights), thus resolving the contradiction through parameter adaptation.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the system uses only an ambient light sensor, then the device complexity is reduced, but the ability to detect direct glare from headlights is insufficient

Engineering Contradiction:
Improvesensor systemVSAvoidglare detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The light sensing function is segmented into two distinct sensors with different roles: an ambient light sensor for measuring overall environmental light levels, and a direct glare sensor specifically positioned to detect intense light sources like headlights. This segmentation allows each sensor to be optimized for its specific function, improving glare detection accuracy without requiring a single overly complex sensor system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system merges the functionality of multiple sensors (ambient light sensor and direct glare sensor) into a coordinated measurement system. The processing system combines inputs from both sensors to make informed decisions about camera integration time adjustment. This merging approach enhances measurement precision for glare detection while maintaining reasonable device complexity through efficient sensor integration and coordinated processing.

Inventive Principle:
Principle #5Merging (Combining)

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 adjusts camera sensitivity to maintain clear images by dynamically responding to ambient and glare conditions, enhancing visibility and preventing image saturation in varying light environments.

Implementation Method 1

adjust the integration time of the camera system based on an input from at least one of an ambient light sensor and a direct glare sensor

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

adjust the integration time of the camera system based on an input from at least one of an ambient light sensor and a direct glare sensor

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 3

adjust the integration time of the camera system... to maintain clear images by dynamically responding to ambient and glare conditions

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP3041712B1A rearview assembly of a vehicle for displaying images
Publication Date: 2018.11.28 GENTEX CORP
  • EP3041712B1 patent drawingFigure 1~2

AI summary

A display system for use in a controlled vehicle is provided, and includes a rearview assembly having a display device located behind a mirror element, a camera system configured to acquire images of a scene external of the controlled vehicle, and a processing system configured to receive a signal representative of the acquired images and to produce an image of the scene on the display device of the rearview assembly, wherein the processing system is further configured to adjust the photosensitivity of the camera system based on an input from at least one of an ambient light sensor and a direct glare sensor.