Meta-Pixel Image Sensor with Color-Separating Lens Array
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Solution Overview
Problem
Image sensors face challenges in reducing pixel size while maintaining light utilization efficiency and noise removal, as conventional color filters absorb a significant portion of incident light and have low light transmission efficiency.
Innovation Solution
An image sensor with a meta-pixel structure featuring a pixel array with a complementary pattern arrangement, utilizing a color separating lens array and optical diffuser to separate and condense light according to wavelengths, and an auto-focusing method that utilizes phase difference signals for precise focusing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a color filter is used to display images with various colors, then color reproduction is achieved, but light utilization efficiency is low because most incident light is absorbed
Solution Approach 1:
The patent replaces the conventional color filter (mechanical/optical filtering) with a color separating lens array that uses diffraction and refraction characteristics to separate colors. This substitution eliminates the need for light-absorbing color filters and enables wavelength-dependent light transmission through optical dispersion mechanisms, thereby resolving the contradiction between color reproduction and light utilization efficiency
Solution Approach 2:
The patent changes the operating parameters of light separation from absorption-based filtering to refraction-based dispersion. By utilizing the refractive index and diffraction characteristics of the lens array, the system achieves color separation through parameter changes in light propagation rather than through absorption, improving light utilization while maintaining color information
2Measurement precision
If pixel size is reduced to increase the number of pixels, then resolution is improved, but light collection capability and noise removal become more difficult
Solution Approach 1:
The patent introduces the optical dimension by placing a color separating lens array above the pixel array. This adds a vertical optical processing layer that enables wavelength-dependent light routing to specific pixels, allowing small pixels to effectively collect and direct light based on color information rather than just geometric area, thus maintaining resolution while improving light collection efficiency
Solution Approach 2:
The color separating lens array acts as an intermediary between the incident light and the pixel array. It mediates the light distribution by separating different wavelengths and directing them to corresponding pixels, enabling small pixels to receive sufficient light intensity through intelligent optical routing rather than relying solely on pixel area
3Illumination intensity
If a color separating lens array is used to increase light usage efficiency, then light transmission is improved, but device complexity increases
Solution Approach 1:
The color separating lens array performs multiple functions simultaneously: it focuses light onto pixels, separates different colors/wavelengths, and enables wavelength-dependent directivity adjustment. By combining these functions into a single optical component structure, the patent reduces overall device complexity compared to using separate color filter arrays and focusing elements
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 improves focusing accuracy by effectively separating and condensing light onto corresponding pixels, reducing light loss and enhancing image quality.
Implementation Method 1
The color separating lens array may separate the colors of the incident light using diffraction or refraction characteristics of other light according to wavelengths
Implementation Method 2
The color separating lens array may separate the colors of the incident light using diffraction or refraction characteristics of other light according to wavelengths
Implementation Method 3
may adjust directivity for each wavelength according to refractive indices and shapes
Data Source
AI summary
Provided are an image sensor, an electronic device including the image sensor, and an auto-focusing method. The image sensor includes a sensor substrate having a plurality of unit patterns each including a first unit pixel, a second unit pixel, a third unit pixel, and a fourth unit pixel, a color separating lens array provided above the sensor substrate and including a plurality of nanoposts that are configured to separate incident light according to wavelengths in each unit pixel and condense the incident light onto corresponding pixels, and an optical diffuser provided on the color separating lens array, wherein each of the first to fourth unit pixels includes four or more pixels that have a complementary pattern structure of a diagonal arrangement.