Dual-Sided Image Sensor Pixel Array for High Dynamic Range
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Solution Overview
Problem
Conventional CMOS image sensors face challenges in capturing high dynamic range images due to small photodiodes, leading to image lag and increased manufacturing costs with bulky dual-sided image sensor chips and optical errors from beam combiners.
Innovation Solution
A dual-sided image sensor with a pixel array capable of capturing images from both frontside and backside illumination using a single pixel array, eliminating the need for bulky camera modules and optical devices, and allowing for precise image registration and improved dynamic range through optical filters and post-processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the size of photodiodes is decreased to increase resolution, then the number of pixels increases, but the dynamic range is reduced and image quality degrades
Solution Approach 1:
The patent transitions from single-sided to dual-sided illumination, adding a spatial dimension to light capture. By receiving light from both front and back sides of the pixel array, the system effectively doubles the light collection capability without increasing physical pixel size, thereby maintaining image quality while preserving small pixel dimensions for high resolution.
Solution Approach 2:
The patent combines two separate illumination paths (front-side and back-side) into a single integrated pixel array system. The pixel array simultaneously processes light from both directions, merging the captured signals to achieve enhanced dynamic range and image quality without requiring separate sensor chips or complex optical combining devices.
2Measurement precision
If impurity concentration of the sensor region is increased to enhance small photodiode performance, then detection sensitivity improves, but image lag increases
Solution Approach 1:
By introducing dual-sided illumination, the system compensates for the image lag issue through temporal and spatial separation of light capture. The backside illumination path provides an alternative route for photons to reach the sensor, effectively distributing the detection burden and reducing the harmful lag effect while maintaining high detection sensitivity through optimized impurity concentration.
3Adaptability or versatility
If two FSI image sensor chips are bonded back-to-back to capture images from both sides, then dual-sided imaging capability is achieved, but device size and manufacturing cost increase
Solution Approach 1:
The patent merges the dual-sided imaging functionality into a single integrated pixel array chip rather than using two separate FSI chips. This consolidation eliminates the need for complex bonding processes, reduces device size, and simplifies the camera module structure while maintaining the capability to capture images from both front and back sides simultaneously.
Solution Approach 2:
The single pixel array chip is designed to perform multiple functions: capturing images from the front side, capturing images from the back side, and potentially combining both signals for enhanced imaging. This multi-functional design replaces what would otherwise require two separate specialized chips, reducing overall system complexity.
4Adaptability or versatility
If two FSI image sensor chips are used to obtain one overlaid image, then image capture flexibility increases, but power consumption and manufacturing cost double
Solution Approach 1:
The patent combines the imaging functionality of two separate chips into a single dual-sided pixel array, thereby halving the power consumption while maintaining the flexibility to capture images from either side or both sides simultaneously. The unified chip architecture allows shared control circuits and processing resources, further reducing overall power requirements.
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
Enables efficient capture and combination of high-quality images from both sides, reducing power consumption and manufacturing costs while enhancing dynamic range and image quality.
Implementation Method 1
A dual-sided image sensor with a pixel array capable of capturing images from both frontside and backside illumination
Data Source
AI summary
An apparatus for a dual-sided image sensor is described. The dual-sided image sensor captures frontside image data incident upon a frontside of the dual-sided image sensor within an array of photosensitive regions integrated into a semiconductor layer of the dual-sided image sensor. Backside image data incident upon a backside of the dual-sided image sensor is also captured within the same array of photosensitive regions.