Photosensor Array with Laterally Varying Transmission Structures
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Solution Overview
Problem
Photosensing with integrated circuits (ICs) faces challenges due to errors caused by inhomogeneities in cell arrays, which affect the accuracy of sensing results.
Innovation Solution
The implementation of photosensor arrays on ICs with transmission structures that have laterally varying light transmission properties, allowing cells to sense specific ranges or subranges of photon energies, and using reference cells for normalization to adjust sensed quantities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If photosensor arrays are implemented on integrated circuits to enable spectral analysis, then the capability to sense photon energies across broad ranges is improved, but errors caused by inhomogeneities in cell arrays increase, reducing measurement accuracy
Solution Approach 1:
The patent applies local quality by making each cell in the photosensor array have different optical transmission properties tailored to its specific function. Reference cells are designed with uniform transmission across all wavelengths, while spectral cells have wavelength-selective transmission characteristics. This local differentiation allows each cell to be optimized for its specific sensing role, enabling broad spectral coverage while maintaining measurement accuracy through proper differentiation of cell functions.
2Measurement precision
If cells are designed to sense specific subranges of photon energies, then spectral resolution is improved, but the complexity of the transmission structure increases
Solution Approach 1:
The patent applies segmentation by dividing the photosensor array into distinct functional segments: reference cells that sense total photon flux and spectral cells that sense specific wavelength subranges. Each cell is equipped with appropriate transmission structures (uniform for reference cells, wavelength-selective for spectral cells). This segmentation allows the system to achieve spectral resolution by comparing signals from different segments, thereby obtaining spectral information without requiring every cell to have complex wavelength-selective structures.
3Measurement precision
If reference cells are used for normalization to adjust sensed quantities, then measurement accuracy is improved, but the device complexity increases due to additional cells and signal processing
Solution Approach 1:
The patent uses reference cells as intermediary elements that mediate between the incident photon flux and the spectral measurement process. These reference cells provide a normalization signal that accounts for variations in total photon flux, allowing the spectral cells to focus on wavelength discrimination. The reference cells act as intermediaries that enable accurate spectral measurements without requiring complex signal processing, by providing a simple normalization factor that corrects for intensity variations.
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 and reliability of photosensing by minimizing errors from inhomogeneities and enabling efficient spectral analysis across a broad range of photon energies.
Implementation Method 1
transmission structures that have laterally varying light transmission properties
Implementation Method 2
photosensor arrays on integrated circuits (ICs)
Data Source
AI summary
An integrated circuit (IC) includes a photosensor array, some cells of which are reference cells that photosense throughout an application's energy range, while other cells of which are subrange cells that photosense within respective subranges. For example, the subrange cells can receive photons in their respective subranges from a transmission structure that has laterally varying properties, such as due to varying optical thickness. The reference cells may be uncoated or may also receive photons through a transmission structure such as a gray filter. Subrange cells and reference cells may be paired in adjacent lines across the array, such as rows. Where photon emanation can vary along a path, quantities of incident photons photosensed by subrange cells along the path can be adjusted based on quantities photosensed by their paired reference cells, such as with normalization.