Color-Separating Lens Array for Low-Loss Image Sensor Color Sensing
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Solution Overview
Problem
Conventional image sensors using color filters suffer from low light utilization efficiency due to significant light absorption, with only about 33% of incident light being transmitted, resulting in substantial light loss.
Innovation Solution
The implementation of a color separating lens array that focuses incident light separately based on wavelengths, utilizing a sensor substrate with specific fine structures and regions to branch and condense light of different wavelengths onto corresponding photosensitive cells, thereby improving light utilization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a color filter is used to sense light color, then color detection is achieved, but light utilization efficiency deteriorates due to absorption of light wavelengths other than the corresponding color
Solution Approach 1:
The invention divides the color separation function into multiple wavelength-specific lens regions within the color separating lens array. Each region is designed to focus specific wavelength ranges onto corresponding photosensitive cells, replacing the absorbing mechanism of color filters with a refractive segmentation approach that directs different wavelengths to appropriate sensors without absorption loss.
Solution Approach 2:
Different regions of the color separating lens array are assigned different optical properties and focal characteristics tailored to specific wavelength ranges. The lens array includes first through fourth regions with distinct fine structures that create different phase distributions for different wavelengths, optimizing local light focusing behavior for each wavelength band while maintaining overall system efficiency.
2Measurement precision
If a color filter absorbs unwanted light wavelengths, then color separation is achieved, but light loss increases significantly
Solution Approach 1:
The invention introduces a color separating lens array as an intermediary optical element between the incident light and the photosensitive cells. This lens array mediates the color separation process through wavelength-dependent refraction and phase modulation, replacing the direct absorption mechanism of color filters with an indirect focusing approach that preserves light energy while achieving spectral separation.
Solution Approach 2:
The invention replaces the absorptive mechanism of color filters with a refractive and phase-based optical system. Instead of mechanically absorbing unwanted wavelengths, the color separating lens array uses optical phase distribution and refraction to direct different wavelengths to appropriate photosensitive cells, substituting an energy-consuming absorption process with an energy-preserving optical routing mechanism.
3Loss of energy
If incident light is focused separately according to wavelengths, then light utilization efficiency improves, but device complexity increases due to the color separating lens array structure
Solution Approach 1:
The color separating lens array performs multiple functions simultaneously: it separates wavelengths, focuses light onto appropriate photosensitive cells, and creates the necessary phase distributions for dual-pixel stereo imaging. This multi-functionality consolidates what would otherwise require separate optical components into a single integrated element, managing complexity while achieving wavelength-specific focusing and color separation.
Solution Approach 2:
The invention merges the color separation function with the focusing function into a single color separating lens array structure. Rather than using separate color filters and separate focusing lenses, the patent combines these functions by integrating wavelength-specific refraction and focusing capabilities into one lens array, reducing the number of components while maintaining both color separation and light focusing 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
This approach enhances light utilization efficiency and color purity in image sensors by effectively directing and focusing light without absorption, potentially eliminating the need for separate micro-lenses and allowing for the use of existing image processing algorithms.
Implementation Method 1
the first fine structure and the second fine structure are configured to form a phase distribution below the plurality of first regions and the plurality of second regions
Implementation Method 2
light of a first wavelength and light of a second wavelength among incident light incident on the color separating lens array are branched into different directions and focused on the first photosensitive cells and the second photosensitive cells, respectively based on the phase distribution
Data Source
AI summary
Provided is an image sensor including a color separating lens array. The image sensor includes a sensor substrate including a plurality of first photosensitive cells and a plurality of second photosensitive cells configured to sense light, and a color separating lens array including a plurality of first regions respectively corresponding to the plurality of first photosensitive cells and each including a first fine structure, and a plurality of second regions respectively corresponding to the plurality of second photosensitive cells and each including a second fine structure that is different from the first fine structure, wherein, among incident light incident on the color separating lens array, light of a first wavelength and light of a second wavelength are branched into different directions and focused on the first photosensitive cells and the second photosensitive cells.