Recording Head Divided Maintenance for Print Density Uniformity

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Solution Overview

Problem

Existing image forming apparatuses fail to perform maintenance operations at appropriate timings, leading to density unevenness and decreased print quality due to ink spreading during maintenance, which is not adequately addressed by prior art.

Innovation Solution

The apparatus performs maintenance operations in a divided manner, considering the states of printing operations, by interrupting the printing process mid-job and conducting maintenance on divided areas of the recording head, with a controller managing both processes to minimize disruption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If maintenance operation is performed periodically on the recording head, then nozzle clogging is prevented, but density unevenness occurs due to ink spreading during maintenance

Engineering Contradiction:
Improvenozzle functionalityVSAvoidprint quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The recording head is divided into multiple unit areas, and maintenance operations are performed separately on each unit area. This segmentation allows the maintenance to be distributed across different time points during printing, preventing concentration of maintenance activities that cause density unevenness while ensuring all areas receive necessary maintenance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Maintenance operations are performed periodically on different unit areas during the printing process rather than in a single集中的 maintenance stop. The controller alternates between printing and maintenance in a periodic manner, performing maintenance on one unit area while continuing to print on others, thus maintaining print quality while preventing nozzle clogging.

Inventive Principle:
Principle #19Periodic action

2Productivity

If maintenance operation is performed in a集中的 manner, then maintenance efficiency is improved, but print quality deteriorates due to density unevenness

Engineering Contradiction:
Improvemaintenance efficiencyVSAvoidprint quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The maintenance operation is segmented into multiple smaller maintenance tasks performed on different unit areas. Instead of performing all maintenance at once, the system divides the recording head into multiple zones and performs maintenance on each zone sequentially during different printing intervals, maintaining both efficiency and quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The printing operation continues uninterrupted while maintenance is performed on different unit areas. The controller manages to perform maintenance on some unit areas while simultaneously printing on others, ensuring the useful action of printing continues without complete interruption, thus maintaining productivity while performing necessary maintenance.

Inventive Principle:
Principle #20Continuity of useful action

3Reliability

If maintenance operation is performed during printing, then nozzle clogging is prevented, but printing is interrupted causing standby time

Engineering Contradiction:
Improvenozzle functionalityVSAvoidprinting interruption
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The recording head is divided into multiple unit areas that can be maintained at different times. The controller performs maintenance on one unit area while continuing to print on other unit areas, thus preventing complete printing interruption. This segmentation allows maintenance to be distributed across multiple smaller time intervals rather than one long interruption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts between printing and maintenance operations based on the current unit area being processed. The controller flexibly manages the timing of maintenance operations on different unit areas, performing maintenance on areas that are not currently being printed, thus optimizing the balance between maintaining nozzle functionality and minimizing printing interruptions.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4667222A1Image forming apparatus, control method of image forming apparatus, and program
Publication Date: 2025.12.24 KONICA MINOLTA INC
  • EP4667222A1 patent drawingFigure 1
  • EP4667222A1 patent drawingFigure 2
  • EP4667222A1 patent drawingFigure 3

AI summary

An image forming apparatus (100) includes: a recording head (3) that performs a printing operation on a recording medium while performing scanning and moving; a maintenance means (70) that performs a maintenance operation on the recording head (3) with a maintenance member (71); and a controller (9) that controls the printing operation of the recording head (3) and the maintenance operation of the maintenance means (70). The controller (9) interrupts the printing operation in a middle of a series of print jobs and causes the maintenance means (70) to perform the maintenance operation. The maintenance operation is a divided maintenance that is performed for each of unit areas (Ar1, Ar2, Ar3, Ar4) into which the recording head (3) is divided. The controller (9) causes the maintenance means (70) to perform, based on states of the printing operation and the divided maintenance, either a first maintenance operation that is performed at a normal time and a second maintenance operation that is different from the first maintenance operation.