Rolling Shutter Barcode Scanner Motion Blur Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rolling shutter sensors in bar code scanners suffer from motion artifacts such as skew and blur due to uneven exposure times across image rows, limiting their motion tolerance and making them less suitable for applications requiring high motion tolerance compared to global shutter scanners.
Innovation Solution
Implementing a 'fluttering flash' method where the light source illuminates the bar code at multiple specific times during the rolling shutter sequence, allowing for de-blurring and de-skewing of images by comparing exposure times and using software algorithms to enhance image clarity, and incorporating motion sensors for velocity and direction information to improve image capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If rolling shutter sensors are used in bar code scanners, then device cost and size are reduced, but motion tolerance is limited due to artifacts
Solution Approach 1:
The patent implements a periodic flashing light source that illuminates the bar code at multiple specific times during the rolling shutter sequence. This periodic illumination creates multiple exposure opportunities for each row of pixels, allowing the system to capture sufficient light information while compensating for the rolling shutter's sequential row-by-row scanning. The periodic action enables rolling shutter scanners to achieve motion tolerance comparable to global shutter scanners while maintaining lower cost.
2Volume of moving object
If rolling shutter sensors are used in bar code scanners, then device size is reduced, but motion tolerance is limited due to artifacts
Solution Approach 1:
The periodic flashing light source synchronizes with the rolling shutter's sequential scanning to provide multiple illumination opportunities. This allows the compact rolling shutter sensor to capture adequate light information across different rows even during motion, achieving motion tolerance without requiring the larger global shutter sensor architecture.
3Productivity
If rolling shutter sensors are used, then uneven exposure times across image rows occur, but this creates motion artifacts such as skew and blur
Solution Approach 1:
The periodic flashing light source provides multiple synchronized illumination opportunities during the rolling shutter sequence, ensuring that each row of pixels receives adequate light exposure even when the bar code is moving. This compensates for the uneven exposure times inherent in rolling shutter scanning, reducing motion-induced skew and blur while maintaining high scanning speed.
Solution Approach 2:
The system uses feedback from the periodic illumination pattern and the known rolling shutter timing to adjust and optimize the exposure parameters. By analyzing the captured images and comparing them against the expected illumination pattern, the system can identify and correct for motion-induced distortions, improving image quality while maintaining scanning speed.
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
Enhances the motion tolerance of rolling shutter scanners by capturing sharper images that can be effectively de-blurred and de-skewed, improving the readability of bar codes even under motion, thus bridging the gap with global shutter scanners in terms of motion tolerance.
Implementation Method 1
capture light for a first row of pixels of the image of the bar code at a first time... capture light for a subsequent row of pixels of the image of the bar code at a second time
Data Source
AI summary
Methods, devices, and systems for rolling shutter bar code imaging are described herein. One method includes initiating the imaging of a bar code by initiating a sequence of procedures to accumulate a charge in a first row of pixels as they are exposed to light thereby capturing data to create a first row of the image of the bar code at a first time, initiating the sequence of procedures to accumulate a charge in a subsequent row of pixels as they are exposed to light thereby capturing data to create a subsequent row of the image of the bar code at a second time, actuating a light source to illuminate the bar code at multiple specific times during a pre-determined timing sequence, and de-blurring the image data for each row based on the specific times during the pre-determined timing sequence that the light source was actuated.