SPAD Sensor Translation for Superresolution Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image sensors, such as CCD and CMOS, have limited resolution and frame rates, making it difficult to capture high-resolution images in low-light conditions or of moving objects, especially when trying to apply superresolution imaging techniques.
Innovation Solution
An imaging system utilizing single-photon-avalanche diodes (SPADs) with sensor translation capabilities, allowing the image sensor to be moved to multiple spatially shifted positions to capture images, which are then processed to generate enhanced-resolution images beyond the pixel resolution of the sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional image sensors (CCD/CMOS) are used, then the device structure is simple and easy to manufacture, but the resolution and light sensitivity are limited
Solution Approach 1:
The pixel array is divided into multiple independently controllable regions or groups of pixels. By selectively activating and translating different pixel groups to different positions, the system captures multiple images with sub-pixel shifts. This segmentation enables superresolution imaging by combining information from multiple lower-resolution captures, effectively increasing the resolution beyond the physical pixel density without requiring a more complex high-resolution sensor structure.
2Manufacturing precision
If multiple spatially shifted images are captured for superresolution imaging, then the enhanced-resolution image can be generated, but the frame rate decreases due to multiple captures required
Solution Approach 1:
The image sensor incorporates a translation mechanism that dynamically shifts pixel groups to different spatial positions during the imaging process. By translating the sensor at controlled speeds and positions, multiple spatially shifted images are captured in rapid succession. The dynamic translation enables the system to acquire the necessary sub-pixel shifted frames at high speeds, maintaining high frame rates while still obtaining the multiple images needed for superresolution reconstruction.
Solution Approach 2:
The translation mechanism operates periodically, shifting pixel groups to predetermined positions in a repeating cycle. This periodic translation pattern allows the sensor to systematically capture images at different spatial offsets across multiple frames. By synchronizing the periodic translation with the image capture sequence, the system efficiently collects all necessary shifted images for superresolution processing without unnecessary delays, thereby maintaining high productivity.
3Manufacturing precision
If multiple spatially shifted images are captured, then superresolution imaging is achieved, but the time required for capturing multiple images increases
Solution Approach 1:
The translation mechanism is pre-programmed with a sequence of translation positions and timing parameters before image capture begins. Pixel groups are pre-positioned at specific offsets, and the translation schedule is predetermined to capture all necessary spatially shifted images in an optimized sequence. This preliminary preparation eliminates delays during the actual capture process, as the system already knows the exact positions and timing needed for superresolution imaging, thereby minimizing the total capture time.
4Illumination intensity
If SPAD pixels are used for high light sensitivity, then low-light imaging is improved, but the device complexity and cost increase
Solution Approach 1:
The image sensor employs a hybrid pixel structure where SPAD pixels are strategically placed in specific regions or interleaved with conventional pixels, rather than using SPAD pixels throughout the entire array. This local quality approach allows the system to leverage the superior low-light sensitivity of SPADs in critical areas while using simpler, more cost-effective conventional pixels in other regions. The translation mechanism works with this mixed pixel types to capture superresolution images, achieving enhanced low-light performance without the full complexity and cost of a complete SPAD array.
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 high-resolution image capture at high frame rates even in low-light conditions and for moving objects, overcoming the limitations of conventional sensors by effectively applying superresolution imaging.
Implementation Method 1
A single photon incident on the SPAD generates a photo-induced carrier such as an electron
Implementation Method 2
Due to a relatively high voltage bias across the SPAD, this photo-induced carrier triggers an avalanche of secondary carriers to produce an avalanche current pulse
Data Source
AI summary
An imaging system with single-photon-avalanche-diodes (SPADs) and sensor translation for capturing a plurality of first images to enable generation of an enhanced-resolution image includes (a) an image sensor with SPAD pixels for capturing the plurality of first images at a plurality of spatially shifted positions of the image sensor, respectively, and (b) an actuator for translating the image sensor, parallel to its light receiving surface, to place the image sensor at the plurality of spatially shifted positions. A method for capturing a plurality of first images that enable composition of an enhanced-resolution image includes (a) translating an image sensor parallel to its light receiving surface to place the image sensor at a plurality of spatially shifted positions, and (b) capturing, using SPAD pixels implemented in pixel array of the image sensor, the plurality of first images at the plurality of spatially shifted positions, respectively.