Color Filter Isolation Layer for Image Sensor Crosstalk
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Solution Overview
Problem
Image sensors face issues with light crosstalk and loss due to oblique light incidence at the edges, leading to inaccurate color information and reduced light utilization efficiency.
Innovation Solution
Incorporating a color filter isolation layer with a lower refractive index material between adjacent color filters, which totally internally reflects obliquely incident light, and using a color separation element within a transparent dielectric layer to separate light by wavelength, ensuring each color filter receives only its intended light band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If color filters are disposed at edge pixels of the image sensor, then the image sensor can capture light at a wider field of view, but light incident at oblique angles causes color crosstalk and inaccurate color information
Solution Approach 1:
A color isolation layer is introduced as an intermediary component between adjacent color filters. This layer has a refractive index lower than both color filters and includes a light reflecting surface that redirects obliquely incident light. The intermediary layer prevents direct oblique light from reaching adjacent color filters, thereby eliminating color crosstalk while preserving the edge pixel functionality.
Solution Approach 2:
The invention converts the harmful effect of oblique light incidence into a beneficial reflection mechanism. By designing the color isolation layer with a specific low refractive index and incorporating a light reflecting surface, oblique light that would normally cause color crosstalk is instead reflected toward the correct color filter, improving color accuracy at edge pixels.
2Area of stationary object
If color filters are disposed at edge pixels of the image sensor, then the image sensor can capture light at a wider field of view, but light crosstalk between adjacent color filters reduces light utilization efficiency
Solution Approach 1:
The color isolation layer acts as an optical intermediary that prevents light from leaking between adjacent color filters. By positioning this layer between color filters and designing it with reflective properties, the system ensures that light intended for one color filter does not reach adjacent filters, thereby reducing energy loss and improving overall light utilization efficiency.
Solution Approach 2:
The invention transforms the potentially harmful light crosstalk into a beneficial effect by reflecting oblique light back toward its intended color filter. This conversion ensures that light energy that would have been lost to adjacent pixels is instead redirected to the correct sensor element, improving energy efficiency.
3Reliability
If a color isolation layer with light reflecting surface is introduced between adjacent color filters, then color crosstalk and light loss are prevented, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The invention merges multiple functions into a single color isolation layer component. This layer simultaneously provides optical isolation between color filters, reflects oblique light, and maintains structural integrity. By combining these functions into one integrated layer rather than multiple separate components, the device complexity is reduced while maintaining reliable color isolation performance.
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 solution effectively prevents light crosstalk, enhances light utilization efficiency, and ensures accurate color sensing even at edge areas of the image sensor, improving the overall quality of captured images.
Implementation Method 1
Incorporating a color filter isolation layer with a lower refractive index material between adjacent color filters, which totally internally reflects obliquely incident light
Implementation Method 2
a color separation element disposed opposite the first color filter and configured to transmit light of the first wavelength band to the first color filter, and to refract or diffract light of the second wavelength band toward the second color filter
Implementation Method 3
a color separation element disposed opposite the first color filter and configured to transmit light of the first wavelength band to the first color filter, and to refract or diffract light of the second wavelength band toward the second color filter
Data Source
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AI summary
An image sensor (110) including a color filter isolation layer (21) and a method of manufacturing the image sensor. The image sensor includes a plurality of color filters (20R, 20G, 20B) that transmit light of a predetermined wavelength band to a light sensing layer (10). The image sensor also includes an isolation layer (21) disposed between adjacent ones of the plurality of color filters. The isolation layer is formed of a material having a lower refractive index than a refractive index of the color filters, thus totally internally reflecting light incident on the isolation layer from one of the plurality of color filters.