Optical Sensor Shielding Assembly for Ambient Light Rejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical sensor chips face reduced detection accuracy due to signal interference from ambient light, particularly when used outdoors, as the influx of ambient light exceeds signal light, leading to a decreased signal-to-noise ratio.
Innovation Solution
An optical sensor package module is designed with a shielding assembly having an aperture to expose a subset of pixels on the sensor chip, limiting the influx of ambient light and enhancing the signal-to-noise ratio by filtering out unwanted wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the optical sensor chip is exposed to receive light without shielding, then the sensor can detect signal light, but ambient light interferes with detection reducing signal-to-noise ratio
Solution Approach 1:
The patent extracts and blocks harmful ambient light from reaching the sensor chip by introducing a shielding assembly with a light blocking layer. This selective extraction of harmful light components (ambient light) while allowing useful signal light to pass through resolves the contradiction between maintaining detection accuracy and preventing ambient light interference.
Solution Approach 2:
The shielding assembly acts as an intermediary component between the ambient light and the sensor chip. It mediates the interaction by selectively blocking harmful wavelengths while permitting signal light to reach the sensor, thus resolving the contradiction without compromising detection capability.
2Measurement precision
If a shielding assembly is added to block ambient light, then the signal-to-noise ratio increases, but the device structure becomes more complex
Solution Approach 1:
The shielding assembly is merged with the substrate structure, where the light blocking layer is integrated directly onto the substrate surface. This combining of the shielding function with the existing substrate reduces overall device complexity while maintaining the signal-to-noise ratio improvement.
Solution Approach 2:
The substrate serves multiple functions: it provides mechanical support and simultaneously hosts the light blocking layer for ambient light rejection. This multi-functionality reduces the need for separate dedicated shielding components, thereby simplifying the overall device structure while improving measurement precision.
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 solution effectively controls the ratio of signal light to ambient light, significantly increasing the signal-to-noise ratio by blocking most ambient light and allowing only the intended signal light to reach the sensor chip, thereby improving detection accuracy.
Implementation Method 1
The shielding assembly having an aperture on the sensor chip during the package process to expose a subset of pixels... most of the ambient light can be filtered by the shielding element
Data Source
AI summary
An optical sensor package module and a manufacturing method thereof are provided. The optical sensor package module includes a substrate, a sensor chip and a shielding assembly. The sensor chip is disposed on the substrate and includes an array of pixels located at a top side thereof for receiving light. The shielding assembly surrounds the sensor chip for limiting influx of light onto the sensor chip, and the shielding assembly has a first aperture to expose at least a first subset of the pixels that is configured to receive corresponding light.