Adjustable Media Roll Holder for Printhead Wear

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Solution Overview

Problem

Inkjet printers experience print quality defects and premature printhead failure due to uneven use of fluid dispensing elements, as some elements are overused while others remain inactive, especially when switching between different media sizes or types.

Innovation Solution

An adjustable holder for roll-type print media that shifts the position of the media roll relative to the print bar, utilizing a hub assembly with an adjustable spacer and actuator to vary the distance between the hub and the media roll, ensuring more even use of fluid dispensing elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a stationary print bar is used for printing, then printing efficiency is maintained, but print quality defects occur due to uneven use of fluid dispensing elements

Engineering Contradiction:
Improveprinting efficiencyVSAvoidprint quality consistency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The holder assembly is made adjustable along the media width direction, allowing the position of the media roll to be dynamically changed relative to the stationary print bar. This enables periodic shifting of which fluid dispensing elements are used, preventing premature failure of specific elements while maintaining overall printing efficiency.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If media roll position is shifted by moving both supports, then position adjustment is achieved, but the structure becomes complex and alignment is difficult

Engineering Contradiction:
Improvemedia roll position adjustmentVSAvoidholder structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The holder assembly is divided into two independent supports: a first support with a fixed hub and a second support with an adjustable hub position. This segmentation allows the second support to be independently adjusted along the media width direction while the first support remains stationary, simplifying the overall structure and alignment process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An adjustable spacer is introduced as an intermediary element between the second support and the media roll. By modifying the spacer length, the position of the media roll can be precisely adjusted without directly moving the support structure, thereby reducing complexity while achieving versatile position adjustment.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the distance between supports is changed to shift media position, then both support-to-roll distances change, but this causes misalignment and positioning errors

Engineering Contradiction:
Improvemedia position shifting capabilityVSAvoidsupport-to-roll distance consistency
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The holder assembly is segmented into a fixed first support and an adjustable second support. This allows independent adjustment of the second support's position relative to the media roll while maintaining a constant distance between the first support and the media roll, ensuring alignment precision is preserved.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The adjustment mechanism is localized to the second support only, while the first support maintains a fixed, precise position. This local adjustment approach ensures that the critical first support-to-roll distance remains constant for proper alignment, while the second support can be adjusted to achieve the desired media position shift.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3508348B1Media roll holder
Publication Date: 2021.10.06 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3508348B1 patent drawingFigure 1
  • EP3508348B1 patent drawingFigure 2
  • EP3508348B1 patent drawingFigure 3~5

AI summary

A holder (12) for a media roll (22) includes a first support (38) to support a first end of the roll; a second support (42) to support a second end of the roll; and a shifter (50) to change a first distance between the first support and the first end of the roll without changing a second distance between the second support and the second end of the roll. A hub assembly (62) to hold one end of a media roll includes a hub (54) to engage the roll (22), the hub rotatable on an axis; a spacer (52) operatively connected to the hub to vary a distance along the axis between the hub and a support supporting the hub; and an actuator (84) to move the spacer along the axis to vary the distance between the hub and the support.