Printer Media Stack Alignment via Belt and Stopper Actuation

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Solution Overview

Problem

Printer systems face misalignment issues due to high sheet-to-sheet friction, especially in inkjet printers where wet ink increases friction, leading to significant misalignment when sheets are stacked and bound.

Innovation Solution

A printed media stack alignment apparatus and method that shifts sheets to a stopper position and then an eject position, minimizing misalignment to within 2 mm by using a belt, paddle, and stopper actuation modules to align and eject sheets, and a tamper to align the stack, ensuring precise alignment before stapling or output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If sheets are stacked and shifted to a stopper in conventional printer systems, then the printing function is achieved, but high sheet-to-sheet friction causes significant misalignment between sheets

Engineering Contradiction:
Improvesheet alignment precisionVSAvoidsheet-to-sheet friction
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent segments the sheet handling process into distinct phases: individual sheet deposition onto the belt, followed by collective shifting of the entire stack to the stopper position. This segmentation allows each sheet to be placed independently before the group is moved, reducing friction-induced misalignment during the stacking process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary belt mechanism that sheets ride on during transport. This belt acts as a mediator between the sheets and the transport mechanism, allowing sheets to be shifted collectively with reduced friction compared to direct contact with stationary surfaces, thereby improving alignment precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If wet ink is used in inkjet printers, then high quality photograph output is achieved, but sheet-to-sheet friction increases significantly

Engineering Contradiction:
Improveprint qualityVSAvoidsheet friction
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies beforehand cushioning by using the belt intermediary before sheets are stacked together. The belt provides a low-friction surface for sheet transport before they accumulate in a stack, preventing the buildup of friction that would occur with direct sheet-to-sheet contact during the printing process.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent employs dynamic sheet handling where sheets are continuously moved on a moving belt rather than being stationary during transport. This dynamic approach reduces static friction between sheets and allows controlled movement that maintains alignment even when wet ink increases sheet friction.

Inventive Principle:
Principle #15Dynamics

3Productivity

If multiple sheets are shifted to a stopper position, then stack formation is achieved, but misalignment occurs due to friction between sheets

Engineering Contradiction:
Improvestack formation efficiencyVSAvoidedge alignment
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent merges the transport function with the alignment function by using a single belt mechanism that simultaneously moves multiple sheets to the stopper position while maintaining their relative positions. This combining of functions achieves both productivity (multiple sheets per cycle) and precision (maintained alignment) without the need for separate handling operations.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3509851B1Printed media stack alignment apparatus, corresponding non-transitory readable medium, and method for printed media stack alignment
Publication Date: 2024.05.29 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3509851B1 patent drawingFigure 1
  • EP3509851B1 patent drawingFigure 2
  • EP3509851B1 patent drawingFigure 3A

AI summary

According to an example, printed media stack alignment may include actuating a belt and a paddle to shift first and second sheets to a stopper position represented by register of the first and second sheets against a stopper. The stopper may be actuated to shift the first and second sheets to an eject position, where the eject position is intermediate to a sheet deposit position and the stopper position. The belt and the paddle may be actuated to shift the first sheet, the second sheet, and a third sheet received at the sheet deposit position to the stopper position. The stopper may be actuated to shift the first, second, and third sheets to the eject position. Further, an ejector may be actuated to eject a stack including the first, second, and third sheets from the eject position.