Infrared Blocking Layer for Optical Proximity Sensor Crosstalk
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Solution Overview
Problem
Existing optical proximity sensors rely on metal shields to minimize crosstalk and interference between infrared emitters and detectors, which are costly, difficult to manufacture in high volumes, and prone to detachment, leading to reliability issues.
Innovation Solution
The design eliminates the need for a metal shield by using optically transmissive materials with infrared opaque or blocking layers applied to the external surfaces of the sensor components, creating a gap between the emitter and detector to attenuate unwanted light and reduce crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If metal shields are used to minimize crosstalk and interference between infrared emitters and detectors, then optical isolation performance is improved, but manufacturing cost increases and reliability decreases due to detachment issues
Solution Approach 1:
The patent merges the optical isolation function with the existing sensor package structure by integrating infrared blocking layers into the molded housing or substrate. This eliminates the need for separate metal shields and their associated attachment mechanisms, thereby improving reliability while maintaining optical isolation performance.
Solution Approach 2:
The patent replaces the mechanical metal shield system with a non-mechanical infrared blocking layer integrated into the package structure. This substitution eliminates mechanical attachment points that could detach, improving reliability while achieving the same optical isolation goal through material properties rather than mechanical barriers.
2Object-affected harmful factors
If metal shields are used to minimize crosstalk and interference between infrared emitters and detectors, then optical isolation performance is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent combines the optical isolation function with the existing sensor package structure by integrating infrared blocking layers into the molded housing or substrate. This eliminates the need for separate metal shield components and their complex assembly processes, thereby simplifying manufacturing while maintaining optical isolation performance.
Solution Approach 2:
The patent makes the package structure multi-functional by integrating infrared blocking capabilities into the existing housing or substrate material. This allows the same component to serve both structural and optical isolation functions, reducing the total number of parts and simplifying manufacturing processes.
3Object-affected harmful factors
If metal shields are used to minimize crosstalk and interference between infrared emitters and detectors, then optical isolation performance is improved, but production efficiency decreases
Solution Approach 1:
The patent merges the optical isolation function with the existing sensor package structure by integrating infrared blocking layers into the molded housing or substrate. This eliminates the need for separate metal shield components and their complex assembly processes, thereby simplifying manufacturing while maintaining optical isolation performance.
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 the performance of optical proximity sensors by minimizing crosstalk and interference while reducing manufacturing costs and improving reliability, allowing for more efficient production and increased manufacturability.
Implementation Method 1
optically transmissive materials with infrared opaque or blocking layers applied to the external surfaces of the sensor components
Implementation Method 2
creating a gap between the emitter and detector to attenuate unwanted light and reduce crosstalk
Implementation Method 3
creating a gap between the emitter and detector to attenuate unwanted light and reduce crosstalk
Data Source
AI summary
An optical proximity sensor is provided that comprises an infrared light emitter an infrared light detector, a first molded optically transmissive infrared light pass component disposed over and covering the light emitter and a second molded optically transmissive infrared light pass component disposed over and covering the light detector. Located in-between the light emitter and the first molded optically transmissive infrared light pass component, and the light detector and the second molded optically transmissive infrared light pass component is a gap. Layers of infrared opaque, attenuating or blocking material are disposed on at least some of the external surfaces forming the gap to substantially attenuate or block the transmission of undesired direct, scattered or reflected light between the light emitter and the light detector, and thereby minimize optical crosstalk and interference between the light emitter and the light detector.