Dual-Aperture Optical Sensor Cover Layout for Crosstalk Reduction
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Solution Overview
Problem
Optical crosstalk in proximity and gesture sensors, caused by the close proximity of emitting and detection devices, leads to errors in detection due to light reflection and scattering from cover materials, particularly in devices with a single aperture configuration.
Innovation Solution
The use of a dual-aperture optical sensor arrangement with strategically designed cover layers, where one opening is camouflaged by adapting its optical properties to match the surrounding cover layer, increasing the distance between the emitting and detection devices to reduce crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single aperture is used for both emitting and detection devices, then the device complexity is reduced and cosmetic appearance is improved, but the distance between emitting and detection devices decreases causing increased optical crosstalk
Solution Approach 1:
The single aperture is segmented into two separate apertures: a first aperture for the emitting device and a second aperture for the detection device. This segmentation increases the distance between the devices, reducing optical crosstalk while maintaining a unified cosmetic appearance through the cover layer.
Solution Approach 2:
The cover layer is designed with different optical properties in different regions: it is transparent or translucent in the first aperture region to allow emitting light to pass through, and opaque or light-absorbing in the second aperture region to block reflected light from reaching the detection device, thereby reducing optical crosstalk.
2Measurement precision
If the cover layer is made transparent or translucent, then light can pass through for detection, but light reflection and scattering from the cover causes optical crosstalk errors
Solution Approach 1:
The cover layer exhibits spatially varying optical properties: transparent or translucent over the first aperture to enable light transmission for detection, and opaque or light-absorbing over the second aperture to prevent reflected light from causing optical crosstalk, thus improving detection accuracy.
Solution Approach 2:
The cover layer's light-absorbing property over the second aperture, which initially seems to block useful light, actually converts the harmful reflected light into absorbed energy, preventing optical crosstalk and improving detection accuracy by ensuring only light from external objects reaches the detector.
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 effectively reduces optical crosstalk, improving detection accuracy by allowing for a greater separation between the emitting and detection devices while maintaining a seamless appearance to the human eye.
Implementation Method 1
A reflection and/or an absorption characteristics for incident light within a specified spectrum of visible light of at least one of the second and third cover layer is adapted to a reflection and/or an absorption characteristics of the first cover layer for incident light within the specified spectrum
Implementation Method 2
A reflection and/or an absorption characteristics for incident light within a specified spectrum of visible light of at least one of the second and third cover layer is adapted to a reflection and/or an absorption characteristics of the first cover layer
Implementation Method 3
the light may have to pass through a cover glass or cover plastic for example with ink printed on it, light may get reflected by the cover or scattered by the ink
Data Source
AI summary
An optical sensor arrangement comprises an emitting device (E) and a detection device (D) configured to emit and detect, respectively, electromagnetic radiation and a cover (C) arranged to cover the emitting and the detection device (E, D). The sensor arrangement comprises a first cover layer (C1) partially covering an inner surface of the cover (C) and having a first and a second opening located above the emitting and the detection device (E, D), respectively. The sensor arrangement comprises a second and a third cover layer (C2, C3) covering the inner surface at areas of the first and the second opening. A reflection and/or an absorption characteristics of at least one of the second and third cover layer (C2, C3) is adapted to a reflection and/or an absorption characteristics of the first cover layer (C1) for incident light within the specified spectrum.