Infrared Object Detection with Scattering Surface for Specular Surfaces
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Solution Overview
Problem
Imaging-based barcode readers face challenges in detecting objects with specular surfaces, such as cell phones, due to low reflected light and limited detection range, especially when the surface orientation is not within a specific angle, affecting the performance of existing object detecting systems.
Innovation Solution
An improved object detecting system is introduced, utilizing an infrared LED, a photodetector, a reflector, and a partially transparent scattering surface to split outgoing light into directional and scattered paths, increasing the likelihood of reflected light reentering the system's field of view, and enhancing detection capabilities on both specular and non-specular surfaces by expanding the field of view into multiple components pointing in different directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional object detecting system uses a single directional light path, then the system structure is simple, but the detection capability on specular surfaces is poor due to low reflected light reentry
Solution Approach 1:
The patent segments the light path into multiple components by introducing a beam splitter that divides the outgoing light into directional and scattered paths. This segmentation allows the system to detect both specular and non-specular surfaces effectively, resolving the contradiction between simple structure and detection capability.
Solution Approach 2:
The patent introduces a scattering surface as an intermediary element that creates scattered light paths without blocking the direct light path. This intermediary enables detection of specular surfaces by providing alternative light paths that can reenter the detector, improving reliability while maintaining structural simplicity.
2Adaptability or versatility
If the field of view is limited to a single direction, then the system is easy to operate, but the detection range and angle coverage are restricted
Solution Approach 1:
The patent extends the detection capability from a single directional field of view to multiple dimensions by adding scattered light paths that cover different angles. This dimensional expansion allows the system to detect objects at various distances and orientations, improving adaptability while maintaining ease of operation through automated multi-path detection.
3Reliability
If the system uses only direct light paths, then the light intensity is high, but the detection of specular surfaces at various orientations is limited
Solution Approach 1:
The patent changes the light path parameters by introducing scattered light paths with different angles and intensities. This parameter diversification allows the system to detect specular surfaces at various orientations by capturing reflected light that would otherwise miss the detector, improving orientation sensitivity while maintaining sufficient light intensity through the combination of direct and scattered paths.
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 improved object detecting system reduces sensitivity to specular surface orientation, enabling effective detection of objects at various distances and angles, including those with strong specular reflections, thereby improving the performance of imaging scanners on both near and far field objects.
Implementation Method 1
detecting system includes an infrared LED, a photodetector, a reflector, and a partially transparent scattering surface
Implementation Method 2
detecting system includes an infrared LED, a photodetector
Implementation Method 3
partially transparent scattering surface to split outgoing light into directional and scattered paths
Data Source
AI summary
An apparatus includes a light emitting diode operative to emit mostly invisible light within an invisible bandwidth, and a scattering surface configured to scatter a first portion of the invisible light from the light emitting diode out of the window. The scattering surface is also partially transparent to allow a second portion of the invisible light from the light emitting diode to pass through the scattering surface and strike the reflector that is configured to reflect at least some of the second portion of the invisible light towards the window. The apparatus further includes a photodetector configured to detect returned invisible light from the target object.