Optical Fire Detector Common Scattering Volume Interference Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Optical smoke detectors face challenges in distinguishing between smoke and interfering objects like insects or dust due to the need for separate scattering volumes, which increases installation space and complexity.

Innovation Solution

The method employs at least two scattered light arrangements sharing a common scattering volume with overlapping or identical scattering volumes, using Lambertian-type transmitters and receivers to compare scattered signals, allowing for interference detection without separate volumes, thus reducing structural effort and space requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate scattering volumes are used to detect interfering objects, then interference immunity is improved, but device complexity and installation space increase

Engineering Contradiction:

Improveinterference immunityVSAvoidstructural effort

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple scattering volume detections into a single common scattering volume. Instead of using separate scattering volumes for different detection channels, the invention uses one common scattering volume that is monitored by multiple transmitter-receiver arrangements, thereby reducing structural complexity while maintaining interference detection capability through signal comparison

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The common scattering volume serves multiple detection functions simultaneously. The same scattering volume is used by at least two different transmitter-receiver arrangements to detect both smoke and interfering objects, making the scattering volume universal and eliminating the need for separate dedicated volumes for each detection purpose

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If separate scattering volumes are used to detect interfering objects, then interference immunity is improved, but installation space increases

Engineering Contradiction:

Improveinterference immunityVSAvoidinstallation space

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from spatial separation of scattering volumes to angular/separation of detection paths. Instead of using separate volumes in different spatial locations, the invention uses the same volume observed from different angles by multiple transmitter-receiver arrangements positioned at different locations, effectively moving the differentiation from spatial dimension to angular dimension

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If mechanical means are used to deflect light beams for searching the scattered volume, then interfering object detection is improved, but device complexity and space requirements increase

Engineering Contradiction:

Improveinterfering object detectionVSAvoidstructural effort

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical beam deflection systems with multiple stationary transmitter-receiver arrangements. Instead of using mechanical means to deflect a single light beam through different paths, the invention uses multiple fixed optical arrangements that simultaneously provide different detection paths through the common scattering volume, eliminating moving parts and mechanical complexity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach enhances interference immunity by reliably distinguishing smoke from interfering objects with minimal installation space and complexity, suitable for compact fire detectors like those mounted under ceilings.

Implementation Method 1

optical fire detector that works according to the scattered light principle

Methodology Applied

Scientific EffectLight scattering: Scattering

Data Source

PatentEP2608174B1Method for detecting an obstruction in a scatter volume of an optical fire alarm and optical fire alarm

Publication Date: 2016.10.19 SIEMENS SCHWEIZ AG

Figure 1~3

AI summary

The invention relates to a method for detecting an interfering object (12) in a scattering volume (7) of an optical fire detector (1) that operates on the scattering light principle. Furthermore, the invention relates to an optical fire detector (1). In order to achieve increased interference immunity with simple means in a small installation space for the fire detector (1), it is proposed to use a common scattering volume (7) instead of separate scattering volumes.