Image Sensor Meta-Region Lens Array for Filterless Color Routing
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Solution Overview
Problem
Image sensors using color filters suffer from low light utilization efficiency due to absorption of unwanted light wavelengths, resulting in significant light loss.
Innovation Solution
Incorporation of a nano-photonic lens array that separates and condenses light of different wavelength bands onto specific pixels, utilizing nano-structures arranged in a symmetrical pattern to enhance optical efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a color filter is used to sense light color, then light color separation is achieved, but light utilization efficiency deteriorates due to absorption of non-intended wavelengths
Solution Approach 1:
The patent extracts the light separation function from the color filter and relocates it to the nano-photonic lens array. The nano-structures in the lens array perform wavelength-based light routing before the light reaches the pixels, eliminating the need for color filters to absorb unwanted wavelengths. This extraction of the separation function from the filtering mechanism resolves the contradiction by achieving color separation without energy loss through absorption.
Solution Approach 2:
The nano-photonic lens array acts as an intermediary between the incident light and the pixels. Instead of allowing light to directly reach pixels and then filtering it, the lens array mediates the light path by separating different wavelengths and directing them to appropriate pixels. This intermediary approach enables wavelength separation without the energy loss inherent in absorptive color filters.
2Measurement precision
If a color filter absorbs unwanted light wavelengths, then light color purity is improved, but overall light transmission deteriorates
Solution Approach 1:
The patent extracts the wavelength selection function from the color filter and implements it in the nano-photonic lens array. The nano-structures selectively route different wavelengths to appropriate pixels based on their optical properties, achieving color purity without absorbing unwanted wavelengths. This extraction enables high color purity while maintaining high overall light transmission.
Solution Approach 2:
The patent replaces the absorptive filtering mechanism with a refractive/reflective routing mechanism using nano-photonic structures. Instead of mechanically absorbing unwanted wavelengths, the system uses optical routing through nano-lenses to direct different wavelengths to appropriate pixels. This substitution maintains color purity while preserving light energy that would otherwise be absorbed.
3Adaptability or versatility
If an RGB color filter is used, then three color channels are achieved, but 2/3 of incident light is absorbed resulting in only 33% light utilization
Solution Approach 1:
The nano-photonic lens array serves as an intermediary that routes different wavelengths to appropriate pixels before they reach the sensor. By performing wavelength-based routing in the lens array, the system achieves three-color capability without the 2/3 light absorption penalty of traditional RGB color filters, dramatically improving light utilization efficiency.
Solution Approach 2:
The patent extracts the wavelength routing function from the color filter layer and implements it in the nano-photonic lens array. This extraction allows the system to achieve three-color channel capability through optical routing rather than absorptive filtering, eliminating the significant light loss inherent in traditional RGB color filter approaches.
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
Improves light utilization efficiency by allowing more light to be transmitted and focused on the intended pixels, reducing light loss and enhancing image sensor performance.
Implementation Method 1
each of the first meta-region, the second meta-region, the third meta-region, and the fourth meta-region include a plurality of nano-structures configured to color-separate incident light that is incident on the nano-photonic lens array and condense light of a first wavelength band onto the first pixel and the fourth pixel, light of a second wavelength band onto the second pixel, and light of a third wavelength band onto the third pixel
Data Source
Figure 1~2A
Figure 2B~2C
Figure 3A
AI summary
Provided is an image sensor including a sensor substrate comprising a first pixel, a second pixel, a third pixel, and a fourth pixel, and a nano-photonic lens array comprising a first meta-region, a second meta-region, a third meta-region, and a fourth meta-region, wherein each of the first to fourth meta-regions includes a plurality of nano-structures, the first meta-region includes a plurality of pairs of two nano-structures symmetrical in a first direction at different distances in a second direction that is perpendicular to the first direction from a horizontal center line, the horizontal center line passing through a center of the first meta-region along the first direction, and in a direction toward the horizontal center line in the second direction, an interval between two symmetrical nano-structures in the first direction increases, and in a direction away from the horizontal center line in the second direction, the interval between two symmetrical nano-structures in the first direction decreases.