Image Sensor Color Splitter Refraction Light Utilization
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Solution Overview
Problem
Color image sensors face significant light loss due to the absorption of most incident light by color filters, resulting in low light utilization efficiency, typically around 33% with RGB filters, which limits their performance.
Innovation Solution
Incorporating a color splitter with a refractive index of 1.4 to 2.4, made from materials like SiNx, TiO2, ZnS, or optical polymers with nanoparticles, exposed to ambient air, which separates incident light by refracting it towards specific pixel regions, improving light distribution and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If color filters are used to detect color in image sensors, then color detection capability is achieved, but light utilization efficiency deteriorates to about 33%
Solution Approach 1:
The incident light is segmented into different color components using a color splitter that separates light into multiple directions based on wavelength. This allows different color components to be directed to different pixel regions, enabling color detection while improving light utilization efficiency by distributing light to multiple pixels rather than absorbing most of it.
Solution Approach 2:
A color splitter is introduced as an intermediary component between the incident light and the pixel array. This color splitter uses refraction to separate different wavelengths of light and direct them to appropriate pixel regions, serving as a mediator that enables both color detection and improved light efficiency.
2Loss of energy
If color splitter is introduced to improve light utilization efficiency, then light distribution to multiple pixels is improved, but device complexity increases
Solution Approach 1:
The color splitter utilizes changes in refractive index based on wavelength to achieve color separation. By exploiting the physical parameter of refraction that varies with wavelength, the system achieves color splitting functionality without requiring complex mechanical or electronic components, thus improving light efficiency while maintaining relatively simple device structure.
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
The color splitter enhances light utilization efficiency by directing a portion of the incident light to corresponding pixel regions, increasing the amount of light available for red and blue pixels, thereby improving image sensor performance and enabling miniaturization.
Implementation Method 1
a color splitter that is disposed on the light transmission layer, comprises a top surface and a side surface exposed to ambient air, and is configured to transmit a portion of light incident on the color splitter toward a first pixel region and refract a remaining portion of the incident light to second pixel regions adjacent to the first pixel region, according to a difference between a refractive index of the color splitter and a refractive index of the ambient air
Data Source
AI summary
An image sensor including a color splitter and a method of manufacturing the image sensor is provided. The image sensor includes a photoelectric conversion layer; a plurality of color filters disposed on the photoelectric conversion layer; a light transmission layer disposed on the photoelectric conversion layer and the plurality of color filters; and a color splitter that is disposed on the light transmission layer, comprises a top surface and a side surface exposed to ambient air, and is configured to transmit a portion of light incident on the color splitter toward a first pixel region and refract a remaining portion of the incident light toward second pixel regions adjacent to the first pixel region, according to a difference between a refractive index of the color splitter and a refractive index of the ambient air.