Perforated Sheet Stacking Control for Better Alignment

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Solution Overview

Problem

The stacking of sheets with perforations formed on them results in protrusions such as burrs or flashes, leading to a deteriorated stacking state due to the raised areas, especially affecting thin papers with lower stiffness and causing alignment issues.

Innovation Solution

A control unit in the sheet stacking apparatus adjusts the stacking operation based on the presence of perforations, varying the upper limit of stacked sheets to prevent protrusions by stopping the stacking process when a certain number of perforated sheets are detected, ensuring better alignment and preventing stacking failures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If sheets with perforation are stacked on a stacking tray, then the sheets can be collected and stored, but the projected portions (burs or flashes) cause the stacking state to deteriorate and alignment to worsen

Engineering Contradiction:
Improvenumber of stacked sheetsVSAvoidstacking alignment
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent changes the parameter of stacking quantity based on the presence of perforation. When perforated sheets are detected, the stacking quantity is reduced to a value smaller than the normal upper limit. This parameter change prevents the accumulation of projected portions that would otherwise cause alignment deterioration and stacking state degradation.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the stacking operation continues without limitation, then the productivity is improved, but the aligning property of stacked sheets deteriorates due to accumulated projected portions

Engineering Contradiction:
Improvestacking speedVSAvoidstacking stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The control unit detects whether sheets have perforation and uses this feedback information to dynamically adjust the stacking operation. When perforated sheets are detected, the system reduces the stacking quantity to prevent alignment deterioration, thereby maintaining stacking stability while still achieving productive operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent makes the stacking quantity dynamic rather than fixed. The upper limit of stacking quantity is adjusted based on the detected presence of perforated sheets, allowing the system to adapt between normal high-speed stacking and reduced stacking for perforated sheets, thus maintaining both productivity and stability.

Inventive Principle:
Principle #15Dynamics

3Quantity of substance

If multiple sheets with perforation are stacked, then the quantity of processed sheets increases, but the projected portions cause area variation and stacking state deterioration

Engineering Contradiction:
Improvenumber of perforated sheets stackedVSAvoidstacking area uniformity
Core Design Contradiction:
Quantity of substanceVSArea of stationary object

Solution Approach 1:

The patent changes the stacking quantity parameter when perforated sheets are detected, reducing it to a value that prevents the accumulation of projected portions. This ensures that the stacking area remains uniform and the stacking state is maintained, even when processing perforated sheets.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4603437A1Sheet stacking device, image forming system, and information processing device
Publication Date: 2025.08.20 CANON FINETECH NISCA INC
  • EP4603437A1 patent drawingFigure 1
  • EP4603437A1 patent drawingFigure 2
  • EP4603437A1 patent drawingFigure 3

AI summary

A sheet stacking apparatus (100) includes a conveyance unit (512, 513, 514), a discharge unit (515), a stacking unit (751) that stacks the sheet being discharged by the discharge unit, and a control unit (636) that stops a stacking operation of the sheet to the stacking unit according to an amount of sheets stacked on the stacking unit. The control unit stops the stacking operation of the sheet on the stacking unit in response to having a first amount of sheets being stacked on the stacking unit, in a case where a sheet having no perforation provided thereon is stacked on the stacking unit, and stops the stacking operation of the sheet on the stacking unit in response to having an amount of sheets that is smaller than the first amount being stacked on the stacking unit, in a case where a sheet having a perforation provided thereon is stacked on the stacking unit.