Color-Separating Lens Array for Higher-Utilization Image Sensors
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Solution Overview
Problem
Conventional 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
An image sensor incorporating a color separating lens array that branches and focuses incident light according to its wavelength, utilizing a sensor substrate with specific fine structures and a spacer layer to direct light to corresponding photosensitive cells, enhancing light utilization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a color filter is used to sense light color, then color detection capability is achieved, but light utilization efficiency deteriorates due to absorption of non-corresponding wavelengths
Solution Approach 1:
The patent extracts the color separation function from the color filter and relocates it to the lens array. By removing the filtering function from the traditional color filter position and implementing it in the lens array through wavelength-dependent light bending, the system eliminates the absorption loss inherent in color filters while maintaining color detection capability.
Solution Approach 2:
The patent introduces an intermediary mechanism - the lens array with different refractive indices - to perform color separation. Instead of using a color filter that absorbs unwanted wavelengths, the lens array acts as an intermediary that refracts different wavelengths at different angles, directing them to corresponding photosensitive cells without absorption loss.
2Adaptability or versatility
If a color filter absorbs light of other colors, then color selectivity is improved, but light loss increases significantly
Solution Approach 1:
The patent extracts the color selection function from the absorbing color filter and implements it in the lens array through refraction. By taking out the filtering function and relocating it to the optical path before the photosensitive cells, the system achieves color selectivity without the energy loss associated with absorption.
Solution Approach 2:
The patent changes the parameter of color separation from absorption-based to refraction-based. By changing the physical mechanism from absorption (color filter) to refraction (lens array with wavelength-dependent refractive indices), the system maintains color selectivity while eliminating light loss.
3Loss of energy
If incident light is branched into different directions based on wavelength, then light utilization efficiency is improved, but device complexity increases due to fine structure requirements
Solution Approach 1:
The patent merges the color separation function with the focusing function into a single lens array structure. By combining these two functions that are typically performed by separate components (color filter and lens), the system achieves wavelength-dependent light branching without significantly increasing device complexity.
Solution Approach 2:
The lens array performs multiple functions simultaneously: it focuses light onto photosensitive cells and separates light by wavelength. This multi-functionality reduces the need for additional components and fine structures, thereby limiting the increase in device complexity while improving light utilization efficiency.
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 solution significantly improves light utilization efficiency by effectively directing different wavelengths of light to their respective photosensitive cells, reducing light loss and enhancing image sensor performance.
Implementation Method 1
a color separating lens array configured to focus incident light separately according to wavelengths of the incident light
Data Source
AI summary
Provided is an image sensor including a color separating lens array. The image sensor includes a sensor substrate including a plurality of first photosensitive cells and a plurality of second photosensitive cells configured to sense light, and a color separating lens array including a plurality of first regions respectively corresponding to the plurality of first photosensitive cells and each including a first fine structure, and a plurality of second regions respectively corresponding to the plurality of second photosensitive cells and each including a second fine structure that is different from the first fine structure, wherein, among incident light incident on the color separating lens array, light of a first wavelength and light of a second wavelength are branched into different directions and focused on the first photosensitive cells and the second photosensitive cells.