Color Separation Lens Array for Image Sensor Light Utilization
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Solution Overview
Problem
Conventional color filters in image sensors have low light utilization efficiency due to absorption of most incident light, limiting pixel miniaturization and image quality.
Innovation Solution
A color separation element with a spacer layer and a nano-post lens array that controls phase distribution to achieve multi-focusing of light of the same wavelength, allowing for efficient light transmission and improved image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a color filter is used to separate colors, then color separation is achieved, but light utilization efficiency is reduced due to absorption of most incident light
Solution Approach 1:
The patent replaces the conventional color filter system (which relies on absorption) with a color separation element based on refraction and diffraction. The color separation element includes a lens array with different refractive indices for different wavelengths, enabling color separation through optical path differentiation rather than absorption, thereby significantly improving light utilization efficiency while maintaining color separation accuracy
Solution Approach 2:
The patent changes the fundamental parameter of color separation from absorption-based (color filter) to refraction-based (color separation element). By adjusting the refractive index of the lens material and the geometric parameters of the lens array, the system achieves wavelength-dependent focusing without absorbing light, thus resolving the contradiction between light efficiency and color separation performance
2Measurement precision
If the number of pixels is increased, then image resolution is improved, but pixel size is reduced making it difficult to secure sufficient light amount
Solution Approach 1:
The patent segments the incident light into different wavelength components using the color separation element, with each wavelength focused to specific pixel groups. This segmentation allows each pixel to receive sufficient light for its designated wavelength range, enabling high pixel density without compromising light amount per pixel, thus improving image resolution while maintaining light utilization
Solution Approach 2:
The patent introduces a wavelength dimension to the pixel arrangement by implementing periodic regions where pixels are selectively responsive to different wavelengths. This dimensional addition allows the system to multiply the effective light-gathering capacity without increasing physical pixel size, enabling higher resolution with adequate light per pixel
3Adaptability or versatility
If pixels of different colors are arranged in a standard RGB pattern, then color coverage is achieved, but light loss increases due to the 1/3 transmission rate of conventional color filters
Solution Approach 1:
The color separation element serves multiple functions simultaneously: it separates colors by wavelength, focuses light to specific pixel groups, and enables high transmission efficiency. This multi-functionality allows the system to maintain comprehensive color coverage (RGB and beyond) while achieving superior light transmission efficiency compared to conventional RGB filter arrangements
Solution Approach 2:
The patent employs a composite optical system combining the color separation element with a periodic pixel array structure. The color separation element uses materials with specific refractive index characteristics, and when combined with the periodic pixel arrangement, creates a composite system that achieves both broad color coverage and high light transmission efficiency
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 image quality by effectively focusing light of the same wavelength onto specific regions, reducing light loss and improving pixel arrangement.
Implementation Method 1
A color separation element may separate a color of incident light by using a diffraction or refraction characteristic of different light according to a wavelength
Implementation Method 2
A color separation element may separate a color of incident light by using a diffraction or refraction characteristic of different light according to a wavelength
Data Source
AI summary
A color separation element and an image sensor including the same are disclosed. The color separation element includes a spacer layer, and a color separation lens array including at least one nano-post provided in the spacer layer to control a phase distribution of incident light so that light having the same wavelength of the incident light is multi-focused on a plurality of target regions; and periodic regions in which the phase distribution control layer is repeatedly arranged.