Image Sensor With Color-Separating Lens Array for Light Utilization
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Solution Overview
Problem
Image sensors using color filters suffer from low light utilization efficiency due to absorption of light outside the corresponding color, resulting in significant light loss, typically only 33% transmission efficiency.
Innovation Solution
The use of a color separating lens array that focuses incident light separately according to wavelengths, allowing for improved light utilization by condensing different wavelengths onto specific pixels without the need for color filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a color filter is used to sense light color, then color information can be obtained, but light utilization efficiency deteriorates because light of colors other than the corresponding color is absorbed
Solution Approach 1:
The patent removes the color filter component from the image sensor and replaces it with a color separating lens array. This extraction of the color filtering function from the pixel level to the optical level eliminates the light absorption loss inherent in color filters while maintaining color separation capability through wavelength-dependent light routing.
Solution Approach 2:
The patent replaces the mechanical/optical absorption mechanism of color filters with a refractive optical system using a color separating lens array. Instead of absorbing unwanted wavelengths, the lens array refracts and directs different wavelengths to different pixels, achieving color separation through optical path manipulation rather than absorption.
2Illumination intensity
If a color filter is used to separate colors, then color information is obtained, but light transmission efficiency is reduced to about 33%
Solution Approach 1:
The patent converts the wavelength-selective property that causes harm in color filters (absorption of non-corresponding colors) into a beneficial optical routing mechanism. The color separating lens array uses the same wavelength-dependent optical properties to redirect different wavelengths to appropriate pixels, transforming what was previously a loss mechanism into a useful color separation function.
3Productivity
If traditional color filter array is used, then manufacturing is simple, but light utilization efficiency is low
Solution Approach 1:
The patent segments the color separation function by creating a lens array where each lens element is optimized for specific wavelength routing to corresponding pixels. This segmentation of the optical function across multiple lens elements enables efficient wavelength-specific light delivery while maintaining compatibility with existing semiconductor manufacturing processes through standardized lens fabrication techniques.
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
Enhances light utilization efficiency and auto-focusing performance by effectively directing different wavelengths of light to dedicated pixels, potentially doubling the light transmission efficiency compared to traditional color filters.
Implementation Method 1
a color separating lens array including a plurality of nanoposts
Data Source
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AI summary
An image sensor includes a sensor substrate including first, second, third, and fourth pixels, and a color separating lens array, wherein each of the first pixels includes a first focusing signal region and a second focusing signal region that independently generate focusing signals, and the first focusing signal region and the second focusing signal region are arranged to be adjacent to each other in the first pixel in a first direction, and each of the fourth pixels includes a third focusing signal region and a fourth focusing signal region that independently generate focusing signals, and the third focusing signal region and the fourth focusing signal region are arranged to be adjacent to each other in the fourth pixel in a second direction that is different from the first direction.