Windshield Sunload Sensor Layout With Asymmetric Apertures

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Solution Overview

Problem

Conventional sunload sensors are bulky, expensive, and not compatible with modern surface mount technology (SMT), making them unsuitable for direct mounting on the windshield and requiring more space than needed for accurate measurement.

Innovation Solution

A radiation sensor with SMT photodetectors and a radiation screen on a substrate, featuring asymmetric apertures and a diffuser element for even radiation distribution, allowing for compact design, economic production, and compatibility with SMT, enabling direct mounting on the windshield.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional sunload sensors are used, then accurate sunload measurement is achieved, but the device becomes bulky and requires more space than needed

Engineering Contradiction:
Improvesunload measurement accuracyVSAvoidsensor volume
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The sensor is segmented into three distinct photodetectors arranged in a triangular pattern, each detecting radiation from different angular zones. This segmentation allows accurate sunload measurement through comparative signal analysis while maintaining a compact form factor, as each detector requires minimal individual space but together they provide comprehensive measurement capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The photodetectors are arranged in a two-dimensional triangular pattern rather than a linear or stacked configuration. This dimensional arrangement optimizes space utilization by distributing detectors laterally, reducing the overall sensor volume while maintaining accurate angular discrimination capability for sunload measurement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If conventional sunload sensors are used, then sunload detection is achieved, but the cost of production increases

Engineering Contradiction:
Improvesunload detection accuracyVSAvoidproduction cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

Each photodetector is equipped with a specific angular acceptance profile optimized for its position in the triangular arrangement. This local quality differentiation allows each detector to specialize in detecting radiation from particular angular zones, achieving accurate sunload measurement through coordinated operation while using simpler, more cost-effective detector designs compared to conventional sensors.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The sensor employs three relatively simple photodetector elements rather than a single complex detector assembly. This approach uses multiple inexpensive, standardized photodetector components that can be manufactured using conventional processes, reducing overall production cost while maintaining measurement accuracy through the triangular geometric arrangement and signal processing algorithm.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If conventional sunload sensors are used, then measurement function is provided, but assembly complexity and time increase

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidassembly efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The three photodetectors are merged into a single integrated sensor module with a common housing and shared optical path elements. This merging consolidates multiple components into one assembly unit, simplifying the installation process to a single mounting operation while maintaining the complex triangular detector arrangement and angular discrimination capability necessary for accurate sunload measurement.

Inventive Principle:
Principle #5Merging (Combining)

4Volume of moving object

If the sensor is designed for compact size, then space requirements are reduced, but tolerance to photodetector positioning becomes more critical

Engineering Contradiction:
Improvesensor volumeVSAvoidphotodetector positioning tolerance
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The triangular arrangement of photodetectors creates an asymmetric geometric configuration where each detector has a unique angular acceptance profile relative to the incident radiation. This asymmetry, combined with signal processing that compares the three detector outputs, provides robust sunload measurement that is tolerant of minor positioning variations, as the relative geometric relationships are maintained even with small manufacturing tolerances.

Inventive Principle:
Principle #4Asymmetry

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 accurate sunload measurements with reduced space requirements, lower costs, and improved assembly efficiency, while being robust and tolerant to photodetector positioning, enhancing driver comfort and energy efficiency.

Implementation Method 1

Most sunload sensors are of the photodiode (PD) type, which provides a current proportional to the amount of photons received

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

The radiation sensor according to the present invention further comprises a diffuser element which is covering the at least one aperture for diffusing the radiation

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP3537118B1Radiation sensor, vehicle sensor arrangement, and assembly method
Publication Date: 2024.04.03 TE CONNECTIVITY SENSORS FRANCE
  • EP3537118B1 patent drawingFigure 1~2
  • EP3537118B1 patent drawingFigure 3~4
  • EP3537118B1 patent drawingFigure 5~7

AI summary

The present invention relates to a radiation sensor, in particular for use with a vehicle sunload sensor arrangement. Furthermore, the present invention also relates to such a vehicle sensor arrangement and to a method of assembling a vehicle sensor arrangement. A radiation sensor comprises at least one first and one second photodetector (118, 120), and a radiation shaping element, wherein said radiation shaping element comprises radiation blocking means for forming at least one aperture (124, 126) through which the radiation (128) has limited access to said first and second photodetectors (118, 120), and wherein said first and second photodetectors (118, 120) are arranged on a substrate (116) and are distanced apart from each other along a sensor axis (130), and wherein the radiation blocking means is formed by a radiation screen (122) mounted on the substrate (116) to encompass the first and second photodetectors (118, 120).