Individual Print Unit Capping to Prevent Nozzle Clogging

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Solution Overview

Problem

Inkjet printer nozzles can clog due to ink evaporation when not in use, requiring maintenance that may necessitate print head replacement, and existing capping systems are space-consuming.

Innovation Solution

A printing device with a capping unit that can individually cap each print unit, using a connecting mechanism to create a closed environment and prevent evaporation, allowing other units to continue printing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a capping unit is used to prevent nozzle clogging, then nozzle reliability is improved, but the device occupies more space

Engineering Contradiction:
Improvenozzle reliabilityVSAvoiddevice space
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The capping system is segmented to provide individual capping units for each print head or print unit. This allows selective capping of only those nozzles that are not currently in use, rather than capping the entire print head assembly. The segmentation enables space efficiency by capping only the necessary portions while maintaining accessibility to uncapped units.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The capping units are designed to be dynamically movable relative to the print heads. The caps can be positioned over print heads when needed and retracted when not needed, allowing the system to transition between capped and uncapped states. This dynamic capability maintains nozzle reliability when required while minimizing space occupation during printing operations.

Inventive Principle:
Principle #15Dynamics

2Reliability

If all print units are capped to prevent clogging, then nozzle reliability is improved, but productivity of the printing system decreases

Engineering Contradiction:
Improvenozzle reliabilityVSAvoidprinting productivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system segments the capping function to apply to individual print units rather than the entire printing system. This allows selective capping where only non-printing print units are capped while printing units remain accessible and operational. The segmentation enables simultaneous maintenance of reliability for capped units and productivity for uncapped units.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different quality states are applied to different print units based on their operational status. Printing units maintain an uncapped state with full accessibility for high productivity, while non-printing units are capped to prevent clogging. This local differentiation of capping quality ensures that productivity is maintained where needed while reliability is protected where printing is not occurring.

Inventive Principle:
Principle #3Local quality

3Reliability

If maintenance operations are performed on clogged nozzles, then nozzle functionality is restored, but loss of time occurs

Engineering Contradiction:
Improvenozzle functionalityVSAvoidmaintenance time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The capping unit applies preliminary protective action by capping print heads or print units immediately when they are not in use. This preventive capping stops ink evaporation and nozzle clogging before they occur, eliminating the need for subsequent maintenance operations. The preliminary protective measure prevents the problem rather than requiring time-consuming remediation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system converts the potentially harmful effect of ink evaporation into a beneficial protective environment. By capping the print head, the evaporation that would cause clogging is prevented, and the capped environment becomes beneficial for preserving nozzle integrity. The harm of ink drying is transformed into a protected state that maintains nozzle functionality without maintenance intervention.

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

Data Source

PatentEP4656389A1Printing device, printing method and method for capping a print unit
Publication Date: 2025.12.03 CANON KK
  • EP4656389A1 patent drawingFigure 1~2B
  • EP4656389A1 patent drawingFigure 2C~3B
  • EP4656389A1 patent drawingFigure 3C~3F

AI summary

The invention relates to a printing device. The invention further relates to a printing method. In addition, the present invention relates to a method for capping a print unit.