Angle Limiting Filter for Optical Sensor Incidence Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical sensors face challenges in controlling the incidence angle of light with high precision, particularly in spectroscopic sensors, due to limitations in the design of angle limiting filters, which affects wavelength resolution and sensitivity.
Innovation Solution
The optical sensor incorporates an angle limiting filter with a specific size and shape, where the width of the opening (d) is greater than or equal to 2 times the wavelength (λ) times the height (R) of the filter, and the angle limiting filter is formed using a light shielding material on a semiconductor substrate, allowing for precise control of the incidence angle and improved light arrival ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the angle limiting filter is designed with conventional dimensions, then the device structure is simple, but the incidence angle control precision is degraded
Solution Approach 1:
The patent applies parameter changes by establishing a specific mathematical relationship between the filter dimensions (d²/λR≧2) and optical parameters (wavelength λ). This quantitative parameter optimization enables precise incidence angle control without requiring complex filter structures, directly resolving the contradiction between control precision and structural simplicity.
2Measurement precision
If the opening width or height of the angle limiting filter is not optimized, then the filter design is simple, but the wavelength resolution cannot be achieved
Solution Approach 1:
The patent transforms the filter design from qualitative to quantitative by specifying precise dimensional parameters (d²/λR≧2). This parameter optimization enables the filter to achieve desired wavelength resolution while maintaining manufacturability, resolving the contradiction between measurement precision and manufacturing precision.
3Productivity
If the angle limiting filter uses standard dimensions, then the manufacturing process is simple, but the light arrival ratio is reduced
Solution Approach 1:
The patent optimizes the filter dimensions using the parameter relationship d²/λR≧2, which maximizes light arrival ratio while maintaining design simplicity. This quantitative approach improves productivity (light arrival ratio) without significantly complicating the manufacturing process.
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 configuration enables high-precision control of the incidence angle, enhancing wavelength resolution and sensitivity, even in low-light conditions, and allows for the integration of the photodiode and processing circuit, reducing the overall size of the sensor.
Implementation Method 1
an angle limiting filter that limits an incidence angle of incidence light with respect to a light receiving area of the light receiving element
Implementation Method 2
a light receiving element; and an angle limiting filter that limits an incidence angle of incidence light with respect to a light receiving area of the light receiving element
Data Source
AI summary
An optical sensor includes a light receiving element (for example a photodiode) and an angle limiting filter that limits the incidence angle of incidence light with respect to the light receiving area of the light receiving element. When a wavelength of the incidence light is denoted by λ, a height of the angle limiting filter is denoted by R, and a width of an opening of the angle limiting filter is denoted by d, “d2/λR≧2” is satisfied.