Electronic Rearview Mirror Raindrop Notification Without Rain Sensor

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Solution Overview

Problem

Existing electronic inner mirror devices for vehicles become expensive due to the necessity of a rain sensor for detecting raindrops on the rear window glass, and drivers may unnecessarily switch the operation modes from electronic mirror mode to optical mode without removing raindrops.

Innovation Solution

An electronic inner mirror device with a raindrop removing device, such as a rear wiper or rear cleaning device, and an electronic control unit that notifies the occupant of the possibility to remove raindrops when switching from electronic mirror mode to optical mode, thereby avoiding the need for a rain sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rain sensor is installed to detect raindrops on the rear window glass, then the reliability of raindrop detection is improved, but the device cost increases

Engineering Contradiction:
Improveraindrop detection reliabilityVSAvoiddevice cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the raindrop detection function from a dedicated rain sensor and relocates it to the rear camera system. The camera, which already exists for capturing rear window images, is enhanced to detect raindrops by analyzing image data, thereby eliminating the need for a separate rain sensor and reducing device cost while maintaining detection reliability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The rear camera is given multiple functions: it serves both as an imaging device for the electronic inner mirror and as a raindrop detection device. By processing the captured images to identify raindrop patterns, the single camera component performs dual roles, reducing overall system complexity and cost

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

2Reliability

If the electronic mirror mode is switched to optical mode when raindrops are present, then the image display reliability is improved, but the loss of information about raindrop removal capability increases

Engineering Contradiction:
Improveimage display reliabilityVSAvoidraindrop removal information
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The system implements feedback by continuously monitoring raindrop presence through the camera and providing real-time notifications to the driver. When raindrops are detected, the system informs the driver that the wiper can remove them, enabling informed decision-making about mode switching rather than automatic switching that would lose information about removal capability

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary detection of raindrops using the camera before any mode switching occurs. By identifying raindrops in advance and notifying the driver of the wiper's capability, the system prepares the driver to take appropriate action while preserving knowledge about how to resolve the raindrop issue

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the driver switches from electronic mirror mode to optical mode without using the wiper, then the ease of operation is improved, but the productivity of raindrop removal decreases

Engineering Contradiction:
Improvemode switching easeVSAvoidraindrop removal efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The notification system acts as an intermediary between the driver and the wiper function. It provides information about raindrop presence and wiper capability, mediating the driver's decision-making process to choose the most effective action (using the wiper) while maintaining ease of operation through simple notification interfaces

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

This solution reduces the likelihood of unnecessary operation mode switches and eliminates the need for a rain sensor, making the electronic inner mirror device more affordable while allowing occupants to effectively remove raindrops and maintain normal image display.

Implementation Method 1

an electronic inner mirror and a rear camera that is installed at a rear portion of a vehicle and acquires an image behind the vehicle

Methodology Applied
Scientific EffectOptical reflection: Reflection

Implementation Method 2

an optical mirror mode in which it reflects an area behind the vehicle by optical reflection

Methodology Applied
Scientific EffectOptical reflection: Reflection

Data Source

PatentEP4279340B1Electronic inner mirror device, notification control method therefor, and notification control program therefor
Publication Date: 2025.01.29 TOYOTA JIDOSHA KK
  • EP4279340B1 patent drawingFigure 1
  • EP4279340B1 patent drawingFigure 2~3
  • EP4279340B1 patent drawingFigure 4

AI summary

An electronic inner mirror device (100) comprising a camera (14) installed at a rear portion of a vehicle to acquire an image behind the vehicle, an electronic inner mirror (12) that has two operation modes of an electronic mirror mode in which it displays the image and an optical mirror mode in which it reflects an area behind the vehicle, and a raindrop removing device (26, 28) that removes raindrops existing on a rear side of the vehicle with respect to the camera, and further comprises an electronic control unit (10) that notifies an occupant or occupants that raindrops can be removed by the raindrop removing device (26, 28) when the operation modes are switched from the electronic mirror mode to the optical mirror mode in a situation where it is estimated that raindrops exist at a position other than the rear portion of the vehicle.