Optical Sensing Light Shielding for Stray-Light Noise Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical sensing devices suffer from the influence of stray light or ambient light, leading to poor signal-to-noise ratios, and existing designs fail to adequately address the extension distances of light shielding layers relative to driving circuits and sensing pixels.
Innovation Solution
The optical sensing device incorporates a light shielding layer with specific extension distances relative to driving circuits and sensing pixels, reducing the influence of stray light and ambient light through a design that includes multiple layers with varying opening sizes and materials, such as black photoresist and metal, to improve adhesion and manufacturing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a light shielding layer is added to block stray light and ambient light, then the signal-to-noise ratio is improved, but the device complexity increases
Solution Approach 1:
The light shielding layer is integrated within the existing sensor structure, nesting the shielding function within the sensor's layered architecture rather than adding a separate external component. This reduces overall device complexity while maintaining the light blocking function.
Solution Approach 2:
The light shielding layer serves multiple functions simultaneously: it blocks stray light, blocks ambient light, and is positioned to protect both the sensing pixel and driving circuit. This multi-functionality reduces the need for separate shielding components for each function.
2Reliability
If the light shielding layer extends outward from the driving circuit by a sufficient distance, then the shielding effectiveness is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies quantitative parameters for the extension distance (first extension distance greater than or equal to first spacing, second extension distance greater than or equal to second spacing), transforming the shielding design from a qualitative concept to a quantifiable manufacturing specification. This enables standardized production while ensuring effectiveness.
Solution Approach 2:
The light shielding layer is designed to extend outward from both the sensing pixel and driving circuit before final assembly, pre-establishing the shielding boundaries. This preliminary positioning ensures that the extension distances are maintained throughout the manufacturing process without requiring complex real-time adjustments.
3Ease of manufacture
If multiple layers with varying opening sizes are used to improve adhesion and manufacturing efficiency, then the ease of manufacture is improved, but the device complexity increases
Solution Approach 1:
The light shielding structure is divided into multiple layers with different opening sizes, allowing each layer to be optimized for specific functions. This segmentation enables independent manufacturing and quality control of each layer, improving overall manufacturing efficiency despite the increased number of components.
Solution Approach 2:
Different layers have different opening sizes tailored to their specific locations and functions within the sensor. This local quality optimization allows each layer to perform its shielding function most effectively while maintaining compatibility with the overall device architecture.
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 design enhances the signal-to-noise ratio, reduces manufacturing complexity, and improves adhesion between layers, thereby increasing sensitivity and reliability of the optical sensing device.
Implementation Method 1
a light shielding layer with specific extension distances relative to driving circuits and sensing pixels, reducing the influence of stray light and ambient light
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An optical sensing device (SD) is disclosed. The optical sensing device (SD) includes a sensing pixel (210), a driving circuit (220) and a first light shielding layer (310, 320, or 330). The sensing pixel (210) includes a sensing circuit (212) and a sensing element (214) electrically connected to the sensing circuit (212). The driving circuit (220) is electrically connected to the sensing circuit (212). The first light shielding layer (310, 320, or 330) includes at least one first opening (312, 322, or 332) corresponding to the sensing element (214), and the first light shielding layer (310, 320, or 330) is overlapped with the driving circuit (220) in a top-view direction of the optical sensing device (SD).