Vehicle Camera Module Waveguide Filter for EMC Shielding

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Solution Overview

Problem

The use of a plastic camera module housing and lens objective in motor vehicles fails to block electromagnetic waves, leading to electromagnetic interference with the image sensor and potential disturbance of nearby electronic devices, which prevents electromagnetic compatibility (EMC) approval.

Innovation Solution

An electromagnetic waveguide filter is arranged around the lens objective to shield the camera module from undesired electromagnetic radiation, allowing the use of cost-effective non-shielding materials like plastics by blocking external interference and suppressing emitted radiation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of stationary object

If a plastic lens objective and plastic housing are used, then cost and weight are reduced, but electromagnetic shielding capability is lost

Engineering Contradiction:
Improvecamera module weightVSAvoidelectromagnetic interference
Core Design Contradiction:
Weight of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The camera module is segmented into distinct functional zones: an electromagnetic shielded zone containing the image sensor, and an unshielded optical zone allowing light entry. The shielded housing forms a separate enclosure around the sensor, while the lens objective remains externally accessible. This segmentation enables selective shielding of only the sensitive electronic components without blocking optical paths, resolving the contradiction between weight reduction and electromagnetic protection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Electromagnetic shielding is applied locally only where needed - specifically around the image sensor and electronic components - rather than enclosing the entire camera module. The shielded housing creates a localized Faraday cage around sensitive electronics, while the lens objective area remains open for light transmission. This local application of shielding maintains overall module lightness while providing targeted protection against electromagnetic interference.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If a metal housing and lens objective are used, then electromagnetic shielding is provided, but cost and weight increase

Engineering Contradiction:
Improveelectromagnetic shieldingVSAvoidcamera module weight
Core Design Contradiction:
Object-affected harmful factorsVSWeight of stationary object

Solution Approach 1:

The housing is segmented into shielded and unshielded portions. The shielded housing encloses only the image sensor and essential electronic components, while the lens objective and external optical paths remain unenclosed. This segmentation allows using lighter materials for the unshielded portions while maintaining electromagnetic protection where critically needed, reducing overall weight compared to a complete metal enclosure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Metal shielding material is applied locally only around the image sensor chamber rather than throughout the entire housing. The shielded housing creates a localized protective environment for sensitive electronics, while the rest of the housing can use lighter materials. This local application of heavy shielding material minimizes weight increase while maintaining necessary electromagnetic compatibility.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If the sensor is positioned further into the housing, then some shielding is achieved, but space is insufficient and radiation spreads widely

Engineering Contradiction:
Improveelectromagnetic protectionVSAvoidhousing space
Core Design Contradiction:
Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The housing interior is segmented into a compact shielded chamber for the image sensor and separate unshielded regions for the lens objective and light paths. The shielded chamber is optimally sized to enclose only the sensor and immediate electronics, creating an efficient electromagnetic barrier without requiring excessive housing volume. This segmented approach provides effective shielding within limited space constraints.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Electromagnetic shielding is concentrated locally around the image sensor in a compact shielded chamber, rather than attempting to shield the entire housing volume. This localized shielding approach provides maximum electromagnetic protection per unit volume, enabling effective EMI protection within the limited space available in the camera module housing.

Inventive Principle:
Principle #3Local quality

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 solution provides effective electromagnetic interference protection, ensuring electromagnetic immunity and EMC approval by allowing only desired electromagnetic radiation to reach the image sensor while shielding the module and surrounding devices from undesired radiation.

Implementation Method 1

an electromagnetic waveguide filter arranged around at least a portion of the lens objective, wherein the electromagnetic waveguide filter is adapted to electromagnetically shield the one or more electronic components from undesired electromagnetic radiation entering the camera housing and/or to shield the camera surrounding from undesired electromagnetic radiation leaving the camera housing

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Implementation Method 2

an electromagnetic waveguide filter arranged around at least a portion of the lens objective

Methodology Applied
Scientific EffectWaveguide filter: Waveguide

Data Source

PatentEP3489750B1A camera module for a motor vehicle
Publication Date: 2024.01.17 MAGNA ELECTRONICS SWEDEN AB
  • EP3489750B1 patent drawingFigure 1~2
  • EP3489750B1 patent drawingFigure 3

AI summary

A camera module (1) for a motor vehicle comprises a camera housing (2), a lens objective (4) comprises an opening (6) allowing light to enter the camera module (1), and one or more electronic components including an image sensor (7) adapted to sense light which is transmitted through the lens objective (4) towards the image sensor (7). An electromagnetic waveguide filter (8) is arranged around and/or within at least a portion of the lens objective (4). The electromagnetic waveguide filter (8) is adapted to electromagnetically shield the one or more electronic components from undesired electromagnetic radiation entering the camera housing (2) and/or to shield the camera surrounding (11) from undesired electromagnetic radiation leaving the camera housing (2).