Optical Smoke Detector Roughened Chamber Surface

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing optical smoke detectors require complex and costly assembly processes due to numerous parts, and they are limited in color options for the measurement chamber, which can lead to design constraints and increased production costs.

Innovation Solution

The smoke detector incorporates a measurement chamber with a roughened internal surface on the upper part to diffuse radiation, allowing for the use of any color and reducing the number of assembly components by eliminating the need for specific waveguides and physical barriers, with the emitter and receiver mounted close together on a printed circuit board to create a measurement volume without direct radiation interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the measurement chamber is made with smooth internal surfaces and specific color coatings to control radiation, then the optical detection accuracy is improved, but the manufacturing complexity and assembly cost increase

Engineering Contradiction:

Improveoptical detection accuracyVSAvoidmanufacturing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the surface parameter from smooth to rough, transforming the radiation control mechanism from dependent on color coatings and waveguides to dependent on diffuse reflection properties. This allows any color to be used while maintaining optical detection accuracy, as the rough surface scatters radiation uniformly regardless of color.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent eliminates the constraint on color selection for the measurement chamber by using rough surfaces that diffuse radiation. This allows the chamber to be manufactured in any color without affecting optical detection accuracy, thereby simplifying manufacturing and reducing costs associated with specific color coatings.

Inventive Principle:

Principle #32Color changes

2Reliability

If waveguides and physical barriers are added to prevent direct radiation interference, then the detection reliability is improved, but the number of assembly components and production cost increase

Engineering Contradiction:

Improvedetection reliabilityVSAvoidassembly process simplicity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent converts the potentially harmful direct radiation that could interfere with detection into a beneficial diffuse reflection pattern. The rough surface transforms direct radiation into scattered radiation that illuminates smoke particles effectively without creating direct interference paths, eliminating the need for barriers and waveguides.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent removes unnecessary components (waveguides and physical barriers) by extracting their functions and achieving them through the rough surface property alone. The rough surface itself performs the function of controlling radiation paths that previously required separate components.

Inventive Principle:

Principle #2Taking out (Extraction)

3Manufacturing precision

If the emitter and receiver are mounted at a distance with precise angular positioning, then the measurement volume optimization is improved, but the assembly precision requirement and production cost increase

Engineering Contradiction:

Improvecomponent positioning precisionVSAvoidassembly cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The rough surface of the measurement chamber performs the self-service function of optimizing the measurement volume by diffusing radiation uniformly. This eliminates the need for precise angular positioning of the emitter and receiver, as the rough surface automatically creates optimal illumination conditions regardless of the exact component positions.

Inventive Principle:

Principle #25Self-service

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 design simplifies assembly, reduces production costs, and allows for a more versatile color selection for the detector components, while maintaining effective smoke detection capabilities without compromising sensitivity to smoke particles.

Implementation Method 1

any portion of the internal surface of the upper part of the measuring chamber directly obstructing the radiation emitted in the emission cone has a roughness capable of generating a diffuse reflection of this radiation

Methodology Applied

Scientific EffectDiffuse reflection: Reflection

Implementation Method 2

utilizing the Tyndall effect (the phenomenon of light scattering from particles). In such an optical detector, smoke particles are detected by measuring the radiation scattered by these particles

Methodology Applied

Scientific EffectLight scattering: Scattering

Data Source

PatentEP3782139B1Optical smoke detector with scattered radiation

Publication Date: 2022.05.04 WEMAINTAIN

Figure 1~2
Figure 3~5
Figure 6

AI summary

The invention relates to an optical smoke detector with scattered radation, comprising a housing containing a measuring volume accessible to the smoke particles in a measuring chamber comprising a high part (51), said measuring volume being defined by an intersection volume between an emission cone of at least one first radiation emitter (7) having a first predefined emission wavelength, and a receiving cone of a radiation receiver that can receive radiation scattered over smoke particles. According to the invention, any portion of inner surface of the high part (51) of the measuring chamber which directly obstructs the radiation emitted in the emission cone has a roughness that can generate a diffuse reflection of said radiation.