Asymmetric Light Receiving Surface for Gas Detection Signal Stability
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Solution Overview
Problem
Conventional gas detection apparatuses using LED light sources face challenges with reduced signal-to-noise ratio due to the rectangular shape of the incident light flux, where the corners of the flux often fall outside the light receiving element, leading to unstable and inaccurate gas detection.
Innovation Solution
A gas detection apparatus design featuring a light emitting element and a light receiving element with rectangular surfaces, where the light emitting surface and light receiving surface are shaped to have corners and sides that are not parallel, utilizing a light guide member with an off-axis optical system to guide light effectively and minimize the impact of optical aberration and diffraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If an LED light source with rectangular cross-section is used, then the device size is reduced and mass production is enabled, but the corners of the incident light flux fall outside the light receiving element, reducing the signal-to-noise ratio
Solution Approach 1:
The light receiving element is designed with an asymmetric irregular quadrangular shape that precisely matches the transformed image of the rectangular LED light source after passing through the off-axis optical system. This asymmetric configuration ensures that all corners of the rectangular light flux are fully received, maximizing the signal-to-noise ratio while maintaining compatibility with mass-produced LED components.
2Measurement precision
If multiple optical members are disposed in the optical system to lengthen the optical path, then gas detection accuracy is improved, but the image of light is altered due to magnification, reduction, rotation, optical aberration and diffraction
Solution Approach 1:
An off-axis parabolic mirror is introduced as an intermediary optical component that performs multiple functions simultaneously: it lengthens the optical path for improved gas detection accuracy, transforms the rectangular light image into a suitable configuration, and directs all light flux including corners onto the light receiving element. This single off-axis component replaces multiple conventional optical members, achieving path extension while maintaining image stability.
3Device complexity
If the light emitting surface and light receiving surface are aligned with parallel sides, then the optical system is simplified, but the corners of the rectangular light flux fall outside the light receiving element
Solution Approach 1:
The light receiving surface is designed with an asymmetric irregular quadrangular configuration that is rotated relative to the light emitting surface. This asymmetric arrangement, combined with the off-axis optical path, ensures that all four corners of the rectangular LED light flux are fully captured by the light receiving element, achieving complete light flux reception without increasing overall system complexity.
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 configuration enhances the signal-to-noise ratio, enabling stable and highly accurate gas detection by ensuring that the incident light is optimally received, reducing errors from light displacement and optical aberration, and maintaining miniaturization and cost-effectiveness.
Implementation Method 1
a light emitting element provided on a main surface of the substrate for emitting light from a light emitting surface
Implementation Method 2
a light receiving element provided on the main surface of the substrate for receiving the light on a light receiving surface
Implementation Method 3
a light guide member for guiding the light emitted by the light emitting element to the light receiving element
Implementation Method 4
a light guide member for guiding the light emitted by the light emitting element to the light receiving element
Data Source
AI summary
A stable and highly accurate gas detections apparatus is provided. A gas detection apparatus 1 includes a light emitting element 3 provided on a main surface 20 of the substrate 2 for emitting light from a light emitting surface 31; a light receiving element 4 provided on the main surface 20 of the substrate 2 for receiving the light on a light receiving surface 41; and a light guide member 5 for guiding the light emitted by the light emitting element 3 to the light receiving element 4. In plan view of the main surface of the substrate, the light emitting surface 31 and the light receiving surface 41 are shaped to have corners, and side of the light emitting surface 31 after being subjected to a magnification or reduction and a translation do not overlap sides of the light receiving surface 41.