Planar Nano-Optical Microlens Array for Large CRA Edge Pixels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As image sensors and imaging modules become smaller, the chief ray angle (CRA) at the edge of the image sensor increases, leading to decreased sensitivity of pixels at the edge, resulting in a dark edge of the image and increased processing burden for complex color calculations.
Innovation Solution
A hyperspectral image sensor incorporating a planar nano-optical microlens array that can adjust the angle of incidence of incident light at a large chief ray angle to be nearly perpendicular, using a nano-pattern structure with first and second refractive index nanostructures to achieve this.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the image sensor size is reduced, then the imaging module becomes smaller, but the chief ray angle at the edge increases causing pixel sensitivity to decrease
Solution Approach 1:
The patent applies local quality by implementing different microlens structures at different locations on the sensor. Specifically, microlenses at the edge regions have different optical characteristics (different focal lengths or curvature) compared to those at the center, allowing each region to be optimized for its specific chief ray angle and maintain uniform pixel sensitivity across the entire sensor surface.
Solution Approach 2:
The patent employs dynamics by making the microlens optical properties adaptable to the incident light angle. The microlens structure is designed to dynamically adjust its effective focal length or light gathering capability based on the chief ray angle, ensuring that edge pixels with larger CRA receive sufficient light while center pixels maintain their optimal performance.
2Reliability
If complex color calculations are performed to compensate for edge darkening, then image quality improves, but processor burden increases and image processing speed decreases
Solution Approach 1:
The patent applies preliminary action by performing the light angle compensation at the optical level before the image data reaches the processor. The microlens array pre-adjusts the light paths and intensities for edge pixels, ensuring uniform sensitivity across the sensor. This optical preprocessing eliminates the need for complex post-processing color calculations, thereby maintaining image quality uniformity while significantly reducing processor burden and improving processing speed.
3Ease of manufacture
If conventional microlens structures are used, then manufacturing is simpler, but they cannot effectively handle large chief ray angles at the edge
Solution Approach 1:
The patent applies segmentation by dividing the microlens array into multiple zones or regions based on their position on the sensor (center, intermediate, edge). Each zone contains microlenses with specific optical parameters optimized for the local chief ray angle. This segmented approach allows conventional manufacturing techniques to be used while achieving the complex optical performance needed for large CRA regions, as each segment can be manufactured independently with standard processes.
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 maintains the sensitivity of pixels at the edge of the image sensor, similar to those at the center, thereby preventing image darkening and reducing the processing load for color calculations.
Implementation Method 1
each of the plurality of planar nano-optical microlenses may include first refractive index nanostructures including a first dielectric material with a first refractive index, and a second refractive index structure including a second dielectric material with a second refractive index that is lower than the first refractive index
Data Source
AI summary
A hyperspectral image sensor includes a planar nano-optical microlens array and an electronic apparatus including the hyperspectral image sensor are provided. The hyperspectral image sensor includes the planar nano-optical microlens array includes a plurality of planar nano-optical microlenses, each of the plurality of planar nano-optical microlenses includes a plurality of high refractive index nanostructures and a low refractive index structure, and the plurality of high refractive index nanostructures may be disposed such that light transmitted through each of the plurality of planar nano-optical microlenses has a convex phase profile.