Document Transport Roller Speed Differential for Ejection
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Solution Overview
Problem
In automatic document feeders, documents are often difficult to remove after scanning due to being clamped between rollers, leading to inefficiencies in the scan-and-check mode where users need to verify scanned images, as the process of ejecting one document can inadvertently move the next document to the scanning position, requiring reversal and additional scans.
Innovation Solution
A document transporting method that generates a linear speed difference between documents by decelerating or stopping the input roller after the first document is scanned, allowing the second document to remain in front of the scanning position for subsequent scanning, enabling efficient ejection and comparison of the first document's scanned image without disrupting the second document's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the automatic document feeder transports documents continuously to reduce time interval between documents, then productivity is improved, but the document cannot be easily removed after scanning due to being clamped between rollers
Solution Approach 1:
The patent divides the roller system into two independent rollers: a first roller that transports documents through the scanning position, and a second roller that can independently rotate to eject documents. This segmentation allows the ejection function to be separated from the transport function, enabling easy document removal without affecting the continuous transport capability of the first roller.
Solution Approach 2:
The second roller acts as an intermediary mechanism between the scanning position and the output tray. It receives the scanned document from the first roller and provides the additional rotational force needed to eject the document easily, without requiring the user to pull against the damping force of the motor-connected first roller.
2Ease of operation
If the first document is ejected by rotating the roller, then the document can be removed, but the motor damping is enlarged by the decelerating gear set making the document difficult to pull out or prone to tearing
Solution Approach 1:
The patent separates the transport function (first roller connected to motor) from the ejection function (second roller not connected to motor). The second roller can be rotated independently without being constrained by the motor's damping force, allowing easy document ejection without tearing.
Solution Approach 2:
The ejection function is extracted from the motor-driven transport system. The second roller provides the ejection capability independently, removing the harmful effect of motor damping during the ejection process while preserving the continuous transport capability of the first roller.
3Productivity
If the second document is transported to the sheet passageway to save transport time, then productivity is improved, but ejecting the first document transports the second document over the scanning position requiring reversal and additional scans
Solution Approach 1:
The patent separates the transport of the second document from the ejection of the first document. The second document can be transported to a waiting position in the sheet passageway without being forced through the scanning position, while the first document is ejected by the second roller. This prevents the need for reversal and additional scanning.
Solution Approach 2:
The second roller acts as an intermediary that can eject the first document without affecting the position of the second document. It provides selective ejection capability, allowing the first document to be removed while leaving the second document in place for the next scan.
Data Source
AI summary
A method includes the steps of rotating an input roller to transport a first leading edge of a first document from an input tray to an input passageway, a scanning position and an output passageway sequentially; rotating the input roller to transport a second leading edge of a second document from the input tray to the input passageway after a first trailing edge of the first document deviates from the input roller; rotating an output roller to transport the first leading edge from the output passageway to an output tray; and generating a linear speed difference between the input roller and the output roller, after the first trailing edge deviates from the scanning position, to transport the first trailing edge to the output tray, such that the second leading edge is still within the input passageway or the input tray when the first trailing edge deviates from the output roller.