Angular-Response Interference Filter for Optical Cross-Talk Reduction
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Solution Overview
Problem
Conventional optical sensing devices suffer from optical crosstalk due to undesired light waves, which degrade the accuracy of proximity detection, and the use of optical barriers to mitigate this issue increases device size and cost.
Innovation Solution
Employing an interference filter with a dynamic angular response to attenuate undesired light waves based on their angle of reflection, eliminating the need for additional filtering mechanisms like optical isolators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical barriers are used to mitigate optical crosstalk, then detection accuracy is improved, but device size and cost increase
Solution Approach 1:
The patent changes the angular parameter of light propagation by designing the emitter to emit light at angles greater than 45 degrees relative to its central axis. This parameter change causes the undesired light to reflect at angles that are subsequently blocked by the detector's angular acceptance characteristics, reducing optical crosstalk without requiring additional optical barriers.
Solution Approach 2:
Instead of using additional components (optical barriers) to block undesired light paths, the patent inverts the approach by designing the emitter's angular characteristics to naturally direct undesired light into paths that the detector inherently rejects. The detector's angular response is used as the blocking mechanism rather than adding separate blocking components.
2Measurement precision
If optical barriers are used to mitigate optical crosstalk, then detection accuracy is improved, but production cost increases
Solution Approach 1:
The patent changes the angular parameter of light propagation by designing the emitter to emit light at angles greater than 45 degrees relative to its central axis. This parameter change causes the undesired light to reflect at angles that are subsequently blocked by the detector's angular acceptance characteristics, reducing optical crosstalk without requiring additional optical barriers.
Solution Approach 2:
The system uses its own inherent characteristics (the detector's angular acceptance response) to block undesired light paths. The detector's natural angular response serves as the filtering mechanism, eliminating the need for separate optical barrier components and reducing manufacturing complexity and cost.
3Object-affected harmful factors
If conventional filtering mechanisms are used, then optical crosstalk is reduced, but device packaging size increases
Solution Approach 1:
The patent changes the angular parameter of light propagation by designing the emitter to emit light at angles greater than 45 degrees relative to its central axis. This parameter change causes the undesired light to reflect at angles that are subsequently blocked by the detector's angular acceptance characteristics, reducing optical crosstalk without requiring additional optical barriers.
Solution Approach 2:
The patent extracts and utilizes the angular acceptance characteristics of the detector as the filtering mechanism, removing the need for separate optical barrier components. By taking out the filtering function from a separate component and embedding it in the detector's inherent angular response, the device packaging size is reduced.
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
Reduces optical crosstalk effectively, enabling smaller device packaging and lower production costs while maintaining detection accuracy.
Implementation Method 1
an interference filter positioned or disposed on the detector. The interference filter is operable to have a particular filter property that causes the interference filter to attenuate the undesired light wave based on a first angle of reflection of the undesired light wave
Data Source
Figure 1
Figure 2A~2B
Figure 3A
AI summary
An optical device (306) includes an internal cavity and an emitter (102) disposed in the internal cavity (210). The emitter is operable to emit a first light wave (220). The optical device also includes a detector (104) disposed in the internal cavity. The detector is operable to detect a second light wave (225) that is based on the first light wave. The second light wave is susceptible to being coupled with an undesired light wave (235) that is based on the first light wave. The optical device further includes an interference filter (310) disposed on the detector. The interference filter has a filter property that causes the interference filter to attenuate the interfering light wave.