Output Sheet Tray Rear Wall for Stable Sheet Stacking

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Solution Overview

Problem

Existing output-sheet-stacking devices suffer from stacking failures due to the upper end of the impact absorbing part protruding from the rear wall of the tray, leading to variations in sheet positioning and potential misalignment.

Innovation Solution

The device incorporates a tray with a rear wall featuring impact absorbing parts that have inclined surfaces extending diagonally downward, positioned between ribs, allowing sheets to be stacked with the front edge above the rear edge, and utilizing cushioning materials with adjustable attachment for improved impact absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the upper end of the impact absorbing part juts out from the rear wall of the tray, then the impact absorbing part can effectively absorb sheet impact, but stacking failure occurs and sheet positioning varies

Engineering Contradiction:
Improveimpact absorption effectivenessVSAvoidsheet positioning accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The impact absorbing part is designed with an inclined surface that extends diagonally downward, transforming the impact absorption function from a vertical protrusion into a diagonal surface structure. This dimensional change allows the upper end to be recessed from the rear wall surface while maintaining effective impact absorption through the inclined geometry, thereby eliminating stacking failures and positioning variations.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The invention changes the geometric parameters of the impact absorbing part by introducing an inclined surface with a specific angle. Instead of a vertical upper end that protrudes, the inclined surface creates a diagonal extension that recesses from the rear wall while maintaining sufficient length to absorb impact effectively. This parameter change resolves the contradiction between impact absorption and positioning accuracy.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the impact absorbing part is designed with a simple vertical structure, then the device complexity is low, but stacking failure occurs

Engineering Contradiction:
Improveimpact absorbing part structureVSAvoidstacking reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The impact absorbing part transitions from a simple vertical structure to an inclined surface structure that extends diagonally. This dimensional change adds only one geometric feature (the inclined angle) while dramatically improving stacking reliability by preventing stacking failures, thus achieving high reliability with minimal increase in device complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If the impact absorbing part extends vertically to maximize impact absorption, then impact absorption is effective, but sheet alignment is disrupted

Engineering Contradiction:
Improveimpact absorption effectivenessVSAvoidsheet alignment
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

By changing the impact absorbing part from a vertical extension to a diagonal inclined surface, the sheet path is no longer obstructed. The inclined surface allows sheets to slide along the diagonal direction, maintaining effective impact absorption while enabling smooth sheet alignment without disruption.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The inclined surface of the impact absorbing part creates a smooth diagonal transition that guides sheet movement. This curved or angled surface replaces the sharp vertical edge, allowing sheets to align smoothly along the diagonal path without catching or misaligning, thereby improving ease of operation.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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

This configuration reduces stacking failures, supports multiple sheet sizes, and facilitates smooth sheet alignment, enhancing the stability and efficiency of the sheet stacking process.

Implementation Method 1

at least one impact absorbing part provided on the rear wall of the tray and configured to, while receiving the rear edge of the sheet stacked on the tray, absorb an impact caused by a hit of the sheet

Methodology Applied
Scientific EffectImpact absorption: Damping

Data Source

PatentEP4703308A1Output-sheet-stacking device and corresponding image forming system
Publication Date: 2026.03.04 FUJIFILM BUSINESS INNOVATION CORP
  • EP4703308A1 patent drawingFigure 1
  • EP4703308A1 patent drawingFigure 2
  • EP4703308A1 patent drawingFigure 3

AI summary

An output-sheet-stacking device includes: a tray including a rear wall and disposed in a downward direction from an outlet through which a sheet is output, the tray allowing the sheet output from the outlet to be stacked on the tray with the sheet being in a position in which a front edge of the sheet is positioned in an upward direction from a rear edge of the sheet; and at least one impact absorbing part provided on the rear wall of the tray and configured to, while receiving the rear edge of the sheet stacked on the tray, absorb an impact caused by a hit of the sheet, the at least one impact absorbing part including an inclined surface extending diagonally downward as proceeding in an output direction of the sheet and intersecting a surface of the rear wall when viewed from a side.