IR Blocking Filter for Optoelectronic Sensor Photopic Accuracy
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Solution Overview
Problem
Current silicon-based optoelectronic sensors face challenges in accurately mimicking the human photopic response due to sensitivity to both visible and non-visible light, leading to increased margin of error in post-detection compensation calculations and potential sensor saturation from high IR light levels, especially when a spectrally distorting medium is present, which attenuates visible light but allows IR light to pass through.
Innovation Solution
The use of an IR blocking filter in conjunction with post-detection compensation processes to reduce the impact of IR light, combined with visible light filters to manage the spectral response, helps to accurately approximate the photopic response by filtering out IR and visible light components before detection, thereby improving the accuracy of light detection and reducing errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If silicon-based optoelectronic sensors are used to detect light, then the sensor can detect both visible and infrared light, but the sensor produces inaccurate photopic response due to sensitivity to non-visible IR light
Solution Approach 1:
The patent extracts and removes the harmful IR light component from the detected light spectrum by introducing an IR blocking filter. This filter selectively blocks infrared wavelengths while allowing visible light to pass through to the sensor, thereby eliminating the source of measurement error and enabling accurate photopic response detection.
Solution Approach 2:
The patent introduces an IR blocking filter as an intermediary component between the light source and the optoelectronic sensor. This mediator selectively attenuates IR light before it reaches the sensor, preventing the harmful effect of IR sensitivity while maintaining the sensor's ability to detect visible light for accurate photopic response measurement.
2Measurement precision
If post-detection compensation calculations are used to correct IR sensitivity, then the sensor can account for IR light, but the margin of error increases
Solution Approach 1:
The patent applies preliminary action by blocking IR light before detection occurs. Instead of attempting to compensate for IR sensitivity after detection, the IR blocking filter prevents IR light from reaching the sensor in the first place. This proactive approach eliminates the need for complex post-detection compensation calculations and maintains high measurement precision with minimal margin of error.
3Illumination intensity
If a spectrally distorting medium is present, then visible light is attenuated but IR light passes through, causing sensor saturation
Solution Approach 1:
The patent extracts the harmful IR light component that passes through the spectrally distorting medium by using an IR blocking filter. This filter removes the excess IR light that would otherwise cause sensor saturation, while allowing the attenuated visible light to be detected accurately.
Solution Approach 2:
The patent converts the harmful effect of IR light passing through the spectrally distorting medium into a benefit by using the IR blocking filter to selectively remove only the harmful IR portion. This allows the system to benefit from the spectrally distorting medium's selective transmission while eliminating its harmful IR transmission effect.
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 accuracy of light detection by minimizing the impact of IR light and maintaining the dynamic range of the sensor, allowing for more precise photopic response calculations and reducing sensor saturation, even in environments with spectral distortions.
Implementation Method 1
An IR blocking filter is positioned over first and second optoelectronic sensors to block a first portion of an infrared (IR) light component of the received light
Implementation Method 2
A visible light filter is positioned over the first optoelectronic sensor to block a first portion of a visible light component of the received light
Implementation Method 3
The optoelectronic sensor produces a representation (e.g., an electrical signal) of the detected light
Data Source
AI summary
Semiconductor structures for optoelectronic sensors with an infrared (IR) blocking filter and methods for using such sensors with post-detection compensation for IR content that passes through the IR blocking filter are provided herein.