Sheet Processing Apparatus Folded Bundle Stacking

Solution Overview

Problem

Conventional sheet processing apparatuses face issues with improper stacking of folded sheet bundles, leading to jamming and reduced image processing efficiency due to the drooping of succeeding sheet bundles into the open portion of preceding bundles, especially with thinner sheets and fewer pages.

Innovation Solution

A sheet processing apparatus that moves the preceding sheet bundle upstream to position the open portion opposed to the folded portion of the succeeding sheet bundle, allowing the succeeding sheet bundle to be stacked with its folded portion overlapping the preceding bundle, preventing jamming and improving stacking reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the trailing edge of the folded sheet bundle is positioned outside the operation region of the holding member to avoid interference, then the holding member can move freely, but the spacing between the trailing edge of stacked sheet bundles and the first folding roller pair becomes too broad

Engineering Contradiction:

Improvemovement of holding memberVSAvoidspacing between trailing edge and folding roller

Core Design Contradiction:

Ease of operationVSLength of moving object

Solution Approach 1:

The sheet bundle is preliminarily positioned on the tray at a location that anticipates the subsequent drooping of the folded portion. By pre-placing the bundle in this specific position, the system prepares for the expected deformation without requiring additional active control mechanisms during the stacking process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention converts the harmful drooping effect into a beneficial positioning mechanism. The folded portion naturally droops and gets stuck with the rear edge of the preceding bundle, which inadvertently positions the trailing edge of the succeeding bundle at an appropriate distance from the folding roller, eliminating the need for broad spacing.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Adaptability or versatility

If the folded portion of the succeeding sheet bundle droops down due to small sheet thickness and low stiffness, then the sheet bundle is more flexible, but the folded portion enters the open portion of the preceding bundle causing jamming

Engineering Contradiction:

Improveflexibility of sheet bundleVSAvoidstacking reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The sheet bundle is preliminarily positioned on the tray at a location that anticipates the subsequent drooping of the folded portion. By pre-placing the bundle in this specific position, the system prepares for the expected deformation without requiring additional active control mechanisms during the stacking process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention converts the harmful drooping effect into a beneficial positioning mechanism. The folded portion naturally droops and gets stuck with the rear edge of the preceding bundle, which inadvertently positions the trailing edge of the succeeding bundle at an appropriate distance from the folding roller, eliminating the need for broad spacing.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of operation

If the folded sheet bundles are stacked with broad spacing to prevent interference with the holding member, then the holding member can operate freely, but the folded portion of succeeding bundles droops and gets stuck with preceding bundles

Engineering Contradiction:

Improveoperation of holding memberVSAvoiddrooping and jamming of sheet bundles

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The sheet bundle is preliminarily positioned on the tray at a location that anticipates the subsequent drooping of the folded portion. By pre-placing the bundle in this specific position, the system prepares for the expected deformation without requiring additional active control mechanisms during the stacking process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention converts the harmful drooping effect into a beneficial positioning mechanism. The folded portion naturally droops and gets stuck with the rear edge of the preceding bundle, which inadvertently positions the trailing edge of the succeeding bundle at an appropriate distance from the folding roller, eliminating the need for broad spacing.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS7681872B2Sheet processing apparatus and image forming apparatus

Publication Date: 2010.03.23 CANON KK

AI summary

The sheet processing apparatus is provided with a second folding, conveying roller pair that discharges a folded sheet bundle with its folded portion being the leading edge and a folded bundle tray provided below the second folding, conveying roller pair on which the sheet bundle discharged by the second folding, conveying roller pair is to be stacked and that moves the stacked sheet bundle. Before a succeeding sheet bundle is discharged onto a preceding sheet bundle, the folded bundle tray moves the preceding sheet bundle in the upstream direction with respect to the sheet conveyance direction to place the trailing edge of the preceding sheet bundle at a position upstream of the leading edge of the succeeding sheet bundle. Thus, it is possible to provide a sheet processing apparatus that can stack folded sheet bundles with reliability and to improve the image forming efficiency.