Bottom Removal Paper Supply Apparatus with Shutter-Controlled Pickup Roller
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Solution Overview
Problem
Existing bottom removal-type paper supply apparatuses face issues with paper misfeeds when a large amount of paper is stacked, as the frictional force between the paper and the support base becomes too large, preventing accurate single-sheet supply, and when the amount is small, differences in friction coefficients between rollers lead to paper bending and misfeeds.
Innovation Solution
A paper supply apparatus with a first pickup roller at the end of the support base and a second pickup roller at the central portion, equipped with a shutter that opens only when the stacked paper exceeds a prescribed weight or number, assisting the first roller to ensure accurate supply without misfeeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the pressure applied by the pressing roller is increased to obtain sufficient frictional force for transporting paper, then the frictional force between paper and pickup roller is improved, but the frictional force between sheets of paper also increases causing double feeds and paper misfeeds
Solution Approach 1:
The pressing roller is divided into multiple independent pressing sections, each capable of applying pressure to different regions of the paper stack. This allows selective pressing of the bottom sheet without excessively pressing upper sheets, reducing inter-sheet friction while maintaining sufficient friction between the bottom sheet and pickup roller.
Solution Approach 2:
The pressing roller applies localized pressure specifically to the contact region between the bottom sheet and pickup roller, rather than uniformly pressing the entire paper stack. This creates a local high-friction zone where needed while keeping friction between sheets minimal, preventing double feeds.
2Productivity
If a second pickup roller is added to assist the first pickup roller when large amount of paper is stacked, then the paper transport capability is improved, but the device complexity increases
Solution Approach 1:
The second pickup roller is designed with dynamic control mechanisms including a shutter that can open or close based on paper stack conditions. The roller operates only when needed (when large amount of paper is detected), transitioning between active and inactive states to assist the first pickup roller selectively, maintaining productivity while managing complexity through conditional operation.
3Reliability
If the shutter is kept open to allow the second pickup roller to assist paper transport, then the paper supply reliability is improved for large stacks, but the risk of paper bending and misfeeds increases for small stacks
Solution Approach 1:
A paper stack detection mechanism provides feedback about the amount of paper in the stack. Based on this feedback, the shutter is automatically opened when large stacks are detected (enabling second roller assistance) and closed when small stacks are detected (preventing paper bending), ensuring reliable operation across different paper quantities.
Solution Approach 2:
The shutter dynamically transitions between open and closed states based on real-time paper stack conditions. This dynamic control allows the system to adapt its paper transport mechanism to match the actual paper quantity, preventing harmful effects while maintaining reliability.
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 enables reliable, misfeed-free paper supply regardless of the paper stack size by utilizing the second pickup roller only when necessary, preventing paper deformation and misfeeds, and maintaining cleanliness by closing the shutter when not in use.
Implementation Method 1
the bottom sheet of paper 55 is picked by the frictional force acting on the portion contacted by the pickup roller 50
Implementation Method 2
the force with which the paper 55 is pressed against the pickup roller 50
Implementation Method 3
the frictional force acting between sheets of paper
Data Source
AI summary
This invention provides a bottom removal-type paper supply apparatus used in an image reading apparatus or the like which can always accurately supply paper into the image reading apparatus regardless of whether the amount of paper stacked on a paper support base is small or large. In order to transport paper stacked on the paper support base into the apparatus, a first pickup roller to which a pressing force can be applied by a pressing roller and a second pickup roller at a central portion of the paper support base which assists the first pickup roller are provided. The second pickup roller is provided with a shutter. By closing the shutter when the paper stacked on the paper support base is less than or equal to a prescribed number of sheets or weight, the pickup roller and the paper can be prevented from contacting.