Frameless Lens for Motion Sensor Housing Integration

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Solution Overview

Problem

Conventional motion detection devices with passive infrared (PIR) sensors have an obtrusive appearance due to visible frames and shadow lines, which can detract from their integration with surroundings.

Innovation Solution

A motion detection device with a frameless lens that forms the entirety of the visible surface, featuring a Fresnel lens portion on the sensor-facing surface to direct infrared radiation smoothly and uniformly, and a lens holder that provides a curved, continuous outward-facing surface without visible edges or discontinuities, blending in with the environment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a conventional lens with frames and support members is used, then the lens is structurally supported and stable, but the device has an obtrusive appearance with visible edges and discontinuities

Engineering Contradiction:
Improveappearance smoothnessVSAvoidlens support stability
Core Design Contradiction:
ShapeVSStrength

Solution Approach 1:

The lens and its support structure are merged into a single integrated component. The lens includes an integrated support portion that extends from the lens body to engage with the housing, eliminating the need for separate frames and support members. This merging allows the lens to maintain structural stability while presenting a smooth, continuous surface without visible edges or discontinuities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The traditional frame and separate support members are extracted from the design. Instead of having distinct framing elements around the lens, the support function is extracted and integrated directly into the lens structure itself, allowing the lens to be both structurally sound and visually seamless.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of manufacture

If multiple components (lens, frame, support members) are used, then each component can be optimized for its specific function, but the device complexity increases

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidnumber of components
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

Multiple components (lens, frame, support members) are merged into a single integrated lens assembly. The lens includes an integrated support portion that combines the optical function with the structural support function, reducing the total number of parts and simplifying manufacturing processes while maintaining functional optimization.

Inventive Principle:
Principle #5Merging (Combining)

3Shape

If the lens is supported by visible frames and members, then the lens is securely positioned and supported, but the aesthetic appeal and integration with surroundings is reduced

Engineering Contradiction:
Improveaesthetic appearanceVSAvoidlens positioning accuracy
Core Design Contradiction:
ShapeVSEase of operation

Solution Approach 1:

Visible frames and support members are extracted from the design. The lens is positioned and supported without traditional framing elements, achieving a clean aesthetic appearance while maintaining secure positioning through the integrated support structure that engages with the housing internally.

Inventive Principle:
Principle #2Taking out (Extraction)

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 device achieves a clean, unobtrusive appearance that allows it to seamlessly integrate with its surroundings, enhancing its aesthetic appeal and functionality while maintaining effective motion detection capabilities.

Implementation Method 1

A sensor-facing surface of the lens in the focusing region is formed having surface features configured to direct infrared radiation toward the sensor. The surface features are arranged to form a Fresnel lens.

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

passive infrared (PIR) motion sensors are used as motion detectors to detect motion of a relatively warm body that emits a relatively high level of infrared radiation

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Data Source

PatentEP3369080B1Detector lens
Publication Date: 2019.08.14 ROBERT BOSCH GMBH
  • EP3369080B1 patent drawingFigure 1~3
  • EP3369080B1 patent drawingFigure 4
  • EP3369080B1 patent drawingFigure 5

AI summary

A motion sensor housing (2) includes a base (3) and a lens holder that is supported on the base. The motion sensor is disposed in the housing between the base and the lens holder so as to face the lens holder, and a frameless lens (60) is supported on an outer surface of the lens holder in such a way that the lens provides the outermost surface of the housing. In addition, when the motion sensor housing is viewed facing the lens, the lens holder is not visible, and the outward-facing surface of the lens is free of edges, borders and/or discontinuities.