Color Separation Lens Array for Filterless Image Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image sensors face low light utilization efficiency due to the absorption of unwanted light colors by color filters, leading to significant light loss, particularly in RGB color filters where only about 33% of incident light is transmitted, resulting in inefficiencies in color separation.
Innovation Solution
An image sensor design incorporating a color separation lens array that separates incident light into green, blue, and red wavelengths and multi-condenses each light type onto specific pixel groups, eliminating the need for color filters by using nanoposts in correspondence regions to create phase profiles that align with pixel arrangements, enhancing light efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a color filter is used to separate colors in an image sensor, then color separation is achieved, but light utilization efficiency deteriorates due to absorption of non-intended light colors
Solution Approach 1:
The patent extracts and removes the color filter component from the image sensor system. Instead of using a color filter to separate colors, the invention uses a pixel array where each pixel is dedicated to detecting a specific color (red, green, or blue), thereby eliminating the light absorption losses inherent in color filter-based color separation
Solution Approach 2:
The patent segments the pixel array into distinct regions where each pixel is assigned to detect a specific color wavelength. This segmentation allows direct detection of different colors by dedicated pixels without requiring a color filter, thus improving light utilization efficiency while maintaining color separation capability
2Measurement precision
If an RGB color filter is used, then color separation is achieved, but light transmission efficiency deteriorates to only about 33% due to absorption of two-thirds of incident light
Solution Approach 1:
The patent removes the RGB color filter from the system and replaces it with a multi-pixel detection architecture where each pixel is tuned to detect a specific color, thereby eliminating the 67% light absorption loss and achieving much higher light transmission efficiency
Solution Approach 2:
The patent replaces the optical filtering mechanism (color filter) with a detector-based color separation mechanism. Instead of using a color filter to block unwanted wavelengths, the system uses multiple pixels with different spectral responses to directly detect different colors, substituting an optical filtering approach with a detector differentiation approach
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 design improves light efficiency by ensuring that light is effectively focused onto corresponding pixels, reducing light loss and enhancing image sensor performance compared to traditional systems.
Implementation Method 1
a color separation lens array configured to: separate incident light into green light, blue light, and red light, according to wavelengths
Implementation Method 2
multi-condense the blue light onto the plurality of first pixels, multi-condense the green light onto the plurality of second pixels, and multi-condense the red light onto the plurality of third pixels
Data Source
AI summary
An image sensor includes a sensor substrate including first to third pixel groups, and a color separation lens array configured to separate incident light according to wavelengths, multi-condense blue light onto a plurality of continuously arranged first pixels of the first pixel group, multi-condense green light onto the plurality of continuously arranged second pixels of the second pixel group, and multi-condense red light onto the plurality of continuously arranged third pixels of the third pixel group. The color separation lens array includes first to third pixel correspondence regions respectively facing the first to third pixel groups and including a plurality of nanoposts. A blue light phase profile viewed in a cross-section immediately after passing through the first pixel correspondence region includes a plurality of maximum points having positions that are not aligned with a center of the plurality of first pixels.