Trailing-Edge Document Stacking via Sloped Tray Inversion
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Solution Overview
Problem
Document transport systems struggle to handle documents of varying sizes and weights while maintaining the original stacking order, leading to potential operator errors and increased costs due to mechanical complexity and expense in existing solutions.
Innovation Solution
A document transport system that employs a combination of edge-sensing, transport timing adjustments, and a specially designed output tray with sloped surfaces to control document velocities and ensure orderly stacking, using paired rollers and motors to manage documents of different sizes and weights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional leading-edge output stacking arrangement is used, then documents of different size and weights can be handled, but document stacking order is not maintained
Solution Approach 1:
The patent inverts the conventional leading-edge stacking approach by using trailing-edge stacking. The output tray is configured with a sloped surface that causes documents to stack at their trailing edges, which naturally preserves the original stacking order. This inversion resolves the contradiction by maintaining document order (reliability) while still accommodating documents of different sizes (adaptability).
Solution Approach 2:
The output tray incorporates a specifically designed sloped surface at the trailing edge area, creating localized quality differentiation. The sloped surface is positioned only where needed to guide document stacking, while the rest of the tray maintains conventional structure. This local modification enables order preservation without requiring complete redesign of the entire stacking mechanism.
2Reliability
If stacker or stacking wheel is used to maintain document order, then document stacking order is preserved, but mechanical complexity and expense increase
Solution Approach 1:
The patent extracts the essential function of order preservation from complex stacking mechanisms like stackers and stacking wheels. By removing these complicated devices and replacing them with a simple sloped output tray surface, the system maintains document ordering capability while dramatically reducing mechanical complexity. The solution takes only the necessary element (sloped surface) and eliminates unnecessary complexity.
Solution Approach 2:
The sloped output tray surface enables documents to self-stack in the correct order through gravity and geometric design, without requiring active control mechanisms. The trailing-edge stacking geometry naturally ensures proper ordering as documents exit the transport system, making the system self-regulating and eliminating the need for complex mechanical stackers or wheels.
3Stability of the object's composition
If output feed mechanism propels document with force to strike retaining wall, then uniform stacking is provided, but document damage and mis-positioning occur
Solution Approach 1:
The sloped output tray surface acts as a cushioning mechanism that gently guides documents into the stack. Instead of allowing documents to strike a retaining wall with force, the slope gradually directs them into position, cushioning against impact and damage. This beforehand guidance prevents mis-positioning and damage while still achieving uniform stacking.
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 system effectively preserves the original stacking order of documents by adjusting exit velocities and using sloped tray surfaces, reducing the likelihood of document misalignment and operator errors, and is more cost-effective and mechanically simpler than existing solutions.
Implementation Method 1
Output trays often have sloped surfaces that cause discharged documents to drift backward, in the -F direction, so that their trailing edges seat against a tapered back wall
Data Source
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AI summary
A method of scanning documents obtains the document that is to be scanned from an input tray, transports the document at a transport velocity past a scanner to obtain image data therefrom, and stacks each scanned document aligned with trailing-edge registration in a sloped output tray, in the order of scanning, by a sequence that detects the trailing edge of the scanned document, feeds the leading edge of the scanned document from an exit nip in a forward direction and above the sloped output tray at a transport velocity, then changes the speed at the exit nip to an exit velocity, different from the transport velocity, according to the timing of the trailing edge detection. The trailing edge of the scanned document is ejected at the exit velocity. The exit nip speed is restored to the transport velocity for feeding the leading edge of a subsequent document.