Optical Sensor Filter Sidewalls for Stray Light Blocking
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Solution Overview
Problem
Conventional light sensing devices using bandpass filters suffer from poor wave filtering, leading to false signals and reduced sensing accuracy due to unwanted light entering the device.
Innovation Solution
The optical sensing device incorporates a bandpass filter layer and a carbonized sidewall to selectively allow specific wavelengths of light to pass through while blocking other wavelengths, thereby enhancing filtering efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a bandpass filter layer is used to selectively allow specific wavelengths to pass through, then the filtering capability for specific wavelengths is improved, but unwanted light can still enter through the sidewalls of the substrate causing false signals
Solution Approach 1:
The patent extends the filtering function from the top surface (where the bandpass filter operates) to the sidewalls of the substrate by forming carbonized sidewalls. This dimensional extension blocks unwanted light from entering through the sidewalls, complementing the top-surface filter and eliminating false signals while maintaining wavelength-selective detection accuracy.
2Object-affected harmful factors
If the substrate thickness is increased to block unwanted light, then the blocking capability is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
Instead of increasing the entire substrate thickness, the patent segments the light-blocking function: the main substrate remains thin for ease of manufacturing, while carbonized sidewalls are selectively formed only at the peripheral regions where light infiltration occurs. This localized approach achieves unwanted light blocking without the complexity and cost of thickening the entire substrate.
3Object-affected harmful factors
If a carbonized sidewall is formed by laser irradiation to block unwanted light, then the light blocking effectiveness is improved, but the manufacturing process complexity increases
Solution Approach 1:
The patent replaces traditional mechanical or chemical sidewall modification methods with laser irradiation. The laser directly carbonizes the sidewall material in a controlled manner, achieving effective light blocking without complex mechanical machining or chemical treatment processes. This substitution simplifies the overall manufacturing workflow while maintaining effectiveness.
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 reduces interference from external light, improving the accuracy of light detection by ensuring only the intended wavelength reaches the optical active area.
Implementation Method 1
The working principle of an optical bandpass filter is based on the interference and reflection of light... interference between multi-layer thin film structures will cause the phases of light with certain wavelengths to be additive and enhanced, while the phases of light with other wavelengths to be destructive and weakened
Implementation Method 2
The working principle of an optical bandpass filter is based on the interference and reflection of light... light will interfere and reflect at the material interface between the multi-layer film structures
Implementation Method 3
The carbonized sidewall covers the sidewall of the filter layer and a portion of the sidewall of the substrate to prevent the light beams with the other wavelengths other than the specific wavelength from being received by the optical acting area through the sidewall of the substrate
Implementation Method 4
the carbonized sidewall is formed by irradiating the sidewall of the filter layer and the portion of the sidewall of the substrate with a high-energy laser beam
Data Source
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AI summary
An optical sensing device and a method for manufacturing the same are provided. The optical sensing device comprises a substrate, an optical acting area, a filter layer and a carbonized sidewall. The optical acting area is disposed on the substrate. The filter layer covers the optical acting area and selectively allows only a light beam with a specific wavelength to pass therethrough and be received by the optical acting area while blocking the light beams with other wavelengths. The carbonized sidewall covers the sidewall of the filter layer and a portion of the sidewall of the substrate to prevent the light beams with the other wavelengths from being received by the optical acting area through the sidewall of the substrate.