Vehicle Key Unit with RF Interference for Keyless Car Sharing

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Solution Overview

Problem

Existing key units for vehicle door locks require users to manually remove the electronic key from a housing unit for engine starting and require cumbersome key transfer processes during car sharing, leading to user inconvenience.

Innovation Solution

A key unit that includes an interference antenna to interfere with communication between the vehicle and electronic key using a first frequency band, a communication antenna for near field communication with a mobile terminal in a second frequency band, and a control unit to manage interference based on communication content in the second frequency band.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electronic key is stored in a housing unit with radio wave shielding, then the communication between vehicle and electronic key is secured, but the user must manually remove the key for engine starting

Engineering Contradiction:
Improvecommunication securityVSAvoidkey removal operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent extracts the harmful radio wave interference function from the housing structure by introducing a separate interference antenna that can be activated independently. This allows the electronic key to remain in the housing unit while the interference antenna blocks external vehicle-to-key communication signals, eliminating the need for manual key removal while maintaining communication security.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The interference antenna acts as an intermediary element between the housing unit and the vehicle's transmission antenna. It mediates the communication by selectively blocking radio waves in the first frequency band while allowing the second frequency band communication to proceed, thus securing the key's location without preventing authorized operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the electronic key is transferred between users for car sharing, then the vehicle can be accessed, but the transfer process becomes troublesome

Engineering Contradiction:
Improvecar sharing capabilityVSAvoidkey transfer process
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The system enables self-service car sharing by allowing the housing unit itself to communicate directly with the vehicle through the second frequency band. The electronic key remains permanently stored in the housing unit, and the housing unit autonomously handles authentication and communication with the vehicle, eliminating the need for physical key transfer between users.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The housing unit is designed with multi-functionality: it serves as both the storage container for the electronic key and an active communication device. The second frequency band communication capability allows the housing unit to function as a standalone key fob, enabling multiple users to access the vehicle without transferring the physical key.

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

3Reliability

If radio wave shielding is provided for the electronic key, then communication interference is prevented, but the device complexity increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidshielding mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the radio wave frequency spectrum into two distinct bands: the first frequency band for vehicle-to-key communication and the second frequency band for housing unit-to-vehicle communication. By targeting interference only at the first frequency band through the interference antenna, the system achieves communication reliability without requiring comprehensive shielding across all frequencies, thus reducing overall device complexity.

Inventive Principle:
Principle #1Segmentation

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

Enables easy and convenient locking and unlocking of vehicle door locks without the need for manual key removal or transfer, improving user experience and simplifying car sharing operations.

Implementation Method 1

an interference antenna configured to propagate, in the air, interference radio waves interfering with communication performed using a first frequency band between a transmission antenna of the vehicle and the electronic key

Methodology Applied
Scientific EffectElectromagnetic wave interference: Interference

Implementation Method 2

a communication antenna configured to communicate with a mobile terminal in a second frequency band different from the first frequency band

Methodology Applied
Scientific EffectNear field communication: Electromagnetic Induction

Data Source

PatentEP4550283A1Key unit
Publication Date: 2025.05.07 AISIN CORP
  • EP4550283A1 patent drawingFigure 1
  • EP4550283A1 patent drawingFigure 2
  • EP4550283A1 patent drawingFigure 3~5

AI summary

A key unit (1) that houses an electronic key (3) of a vehicle (2) includes: an interference antenna (10) configured to propagate, in the air, interference radio waves interfering with communication performed using a first frequency band between a transmission antenna of the vehicle and the electronic key; a communication antenna (12) configured to communicate with a mobile terminal (5) in a second frequency band different from the first frequency band; and a control unit (14) configured to control an output of the interference antenna according to a communication content in the second frequency band.