Paper Transport Guide Surface Layout to Suppress Rear-End Bouncing

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Solution Overview

Problem

Existing transport devices generate a bouncing sound when the rear end of a recording medium disengages from a guide surface that is separated from the transporting roller and has a constant shape in the axial direction, leading to potential damage and noise.

Innovation Solution

The transport device incorporates a guide member with a guide surface that extends to the downstream side in the transport direction, with the leading end positioned on the second roller side relative to the nip line, and includes an inclined surface to guide the rear end corner portion, reducing the bouncing sound and damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the guide member is separated from the transporting roller and the guide surface has a constant shape in the axial direction, then the device structure is simple, but a bouncing sound is generated when the rear end of the recording medium disengages from the guide surface

Engineering Contradiction:
Improveguide member structureVSAvoidbouncing sound
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The guide surface is designed to be non-constant in the axial direction, with the separation portion extending further downstream than the overlapping portion. This dynamic variation in the guide surface shape allows the rear end of the recording medium to be guided smoothly as it disengages, preventing bouncing sound while maintaining structural simplicity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Different portions of the guide member have different guide surface characteristics: the overlapping portion guides the front end of the recording medium, while the separation portion extends further to guide the rear end. This localized differentiation in guide surface shape addresses the bouncing sound problem at the rear end without complicating the overall structure

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If the guide surface is constant in the axial direction, then manufacturing is easier, but the rear end corner of the recording medium may be damaged due to bouncing

Engineering Contradiction:
Improveguide surface fabricationVSAvoiddamage to recording medium
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The guide surface varies in the axial direction with the separation portion extending further downstream than the overlapping portion. This dynamic design ensures the rear end corner of the recording medium is properly supported during disengagement, preventing damage while remaining manufacturable

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The guide surface is designed in advance with the separation portion extending further downstream, so that the rear end of the recording medium is already positioned correctly before it fully disengages from the transporting roller. This preliminary positioning prevents sudden bouncing and potential damage

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4697099A1Transport device and image forming apparatus
Publication Date: 2026.02.18 FUJIFILM BUSINESS INNOVATION CORP
  • EP4697099A1 patent drawingFigure 1
  • EP4697099A1 patent drawingFigure 2
  • EP4697099A1 patent drawingFigure 3

AI summary

A transport device includes a transporting roller that includes a first shaft portion, a first roller configured to have plural cylindrical first roller portions into which the first shaft portion is inserted and which are separated from each other in an axial direction of the first shaft portion, and a second roller coming into contact with the first roller and extends in a direction of the first shaft portion, and that transports a recording medium; and a guide member that is disposed on a first roller side with respect to a transport path of the recording medium and that is formed with a guide surface guiding the recording medium toward the transporting roller while changing a transport direction of the recording medium to be transported, the guide surface of a separation portion which is separated from the first roller in the axial direction extending to a downstream side in the transport direction as compared with the guide surface of an overlapping portion which overlaps the first roller in the axial direction.