Inkjet Head Valve Segmentation for Targeted Maintenance

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Solution Overview

Problem

Conventional inkjet recording apparatuses face inefficiencies in head maintenance, including excessive ink waste, filter clogging, and prolonged maintenance times due to simultaneous capping and series-connected head configurations.

Innovation Solution

An inkjet recording apparatus with individually controllable valves for each head, a common flow path for parallel ink supply, and a bypass flow path to manage pressure, allowing selective maintenance of target heads and reducing ink consumption without the need for filters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If simultaneous capping and ink ejection to cap case is performed for all heads, then air bubbles and foreign substance are discharged from heads, but ink waste increases and maintenance time is prolonged

Engineering Contradiction:
Improvehead ejection performanceVSAvoidink consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The maintenance operation is segmented by head unit. Each head can be maintained independently through individual valve control, allowing selective maintenance of only those heads that require it rather than forcing all heads to undergo maintenance simultaneously. This segmentation enables the system to discharge air bubbles and foreign substance from specific heads without wasting ink on heads that do not need maintenance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically determines which heads require maintenance based on actual ejection performance or maintenance history. The control unit activates maintenance operations only for selected heads rather than statically maintaining all heads, making the maintenance process adaptive and efficient.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If all heads are connected in series for maintenance, then only one filter is needed, but maintenance time is significantly prolonged

Engineering Contradiction:
Improvefilter configurationVSAvoidmaintenance time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The head maintenance system is segmented into independent parallel paths rather than a single series path. Each head has its own maintenance flow path controlled by individual valves, allowing simultaneous or selective maintenance of multiple heads without requiring sequential processing through a single filter system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple head maintenance flow paths are merged at common sections (ink tank, pump, cap case) while maintaining independence at critical control points (individual valves for each head). This merging approach reduces the total number of filters needed while preserving the ability to maintain heads independently and efficiently.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If filters are installed in each head for ink collection, then impurity removal is improved, but device complexity and filter inspection requirements increase

Engineering Contradiction:
Improveink purityVSAvoidfilter configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The filter function is extracted from individual head units and consolidated into a shared filter system located in the common ink flow path. This extraction eliminates the need for multiple filters distributed across heads while maintaining effective impurity removal through the centralized filter that serves all heads.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A single filter system performs the filtering function for all heads universally. The filter in the common ink supply path serves multiple heads simultaneously, providing impurity removal for the entire system without requiring duplicate filter components in each head unit.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Loss of substance

If individual valve control is implemented for each head, then selective maintenance is enabled and ink waste is reduced, but device complexity increases

Engineering Contradiction:
Improveink consumptionVSAvoidvalve control system
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The valve control system is made dynamic and selective rather than static and universal. Individual valves for each head enable the control unit to dynamically determine which valves to open or close based on maintenance requirements, allowing ink to be directed only to heads that need maintenance and preventing waste on heads that do not.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Each head effectively serves its own maintenance needs through individual valve control. The system can identify which heads require maintenance and direct ink flow and maintenance operations specifically to those heads, allowing the system to self-regulate ink consumption based on actual maintenance requirements rather than forcing uniform maintenance on all heads.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution reduces ink consumption, eliminates filter inspection, and shortens maintenance time by enabling efficient and targeted maintenance of individual heads while preventing air bubble and impurity transfer between heads.

Implementation Method 1

closing solenoid valves provided on ink flow paths to supply ink from the ink tank to the heads to bring the cap case at a negative pressure with a pump

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

closing solenoid valves provided on ink flow paths to supply ink from the ink tank to the heads to bring the cap case at a negative pressure with a pump; reducing the pressure in the cap case to a target pressure

Methodology Applied
Scientific EffectNegative pressure: Depressurisation

Data Source

PatentEP2759408B1Inkjet recording apparatus
Publication Date: 2020.08.19 KONICA MINOLTA INC
  • EP2759408B1 patent drawingFigure 1
  • EP2759408B1 patent drawingFigure 2
  • EP2759408B1 patent drawingFigure 3

AI summary

This inkjet recording apparatus is provided with: a plurality of heads (3) that discharge the same color of ink onto a recording medium; an ink tank (84) that stores ink to be supplied to each of the plurality of heads; and a fluid delivery unit (850) that delivers ink from the ink tank to the head side. Each of the heads includes a manifold that is filled with ink and a first and a second ports (341, 342) in communication with the manifold (34) . Ink flow paths respectively connected to the first port and the second port of each head are fitted with open/close switchable valves (874, 875), and a control unit (9) that individually controls the opening and closing of the valves respectively connected to the first and the second ports of each head is provided. The heads can discharge ink individually such that maintenance can be performed quickly while ink consumption is suppressed.