Inkjet Nozzle Unit Position Detection Using Patch Intersections

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Solution Overview

Problem

Inkjet image forming apparatuses face issues with density defects in line or block patterns due to ink ejection malfunctions, leading to incorrect detection of nozzle unit positions.

Innovation Solution

The apparatus includes a recording head with nozzle units, a control unit, and a nozzle unit position detecting unit that prints a test pattern with patch images and determines nozzle positions based on scanned image density distributions, specifically using slanted edges and solid parts to detect intersection points for accurate nozzle positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a line pattern or block pattern test image is printed to detect nozzle unit positions, then the detection method is simple, but density defects occur when ink ejection malfunction occurs leading to incorrect position detection

Engineering Contradiction:

Improvedetection method simplicityVSAvoidnozzle unit position detection accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The test pattern is divided into multiple patch images, each corresponding to a specific nozzle unit. Each patch image contains density information that can be independently analyzed to detect the position of its corresponding nozzle unit, allowing localized position detection even when other nozzles malfunction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses patch images with specific local density characteristics (solid parts between slanted edges) that create distinctive density distributions. By analyzing the density distribution in each local patch region, the system can accurately determine nozzle unit positions based on local density patterns rather than relying on the entire test pattern.

Inventive Principle:

Principle #3Local quality

2Productivity

If ink ejection is performed using nozzles to print test patterns, then the printing process is efficient, but ink ejection malfunction causes density defects that prevent correct position detection

Engineering Contradiction:

Improveprinting efficiencyVSAvoidposition detection reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system performs preliminary position detection using patch images with slanted edges and solid parts before actual printing. The density distribution analysis of these pre-printed patches provides baseline position information that can be used to correct or compensate for nozzle malfunctions during subsequent printing operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where the detected nozzle unit positions from patch image density distributions are used to adjust or correct the printing process. This feedback loop ensures that even if some nozzles malfunction, the system can compensate and maintain reliable position detection and printing accuracy.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20260048590A1Image forming apparatus

Publication Date: 2026.02.19 KYOCERA DOCUMENT SOLUTIONS INC

AI summary

A recording head includes plural nozzle units. A nozzle unit position detecting unit detects positions of the nozzle units on the basis of a scanned image of a test pattern. The test pattern includes patch images corresponding to the plural nozzle units. Each of the patch image includes a first edge along a secondary scanning direction, and a second edge that crosses the first edge. On the basis of a density distribution of the test pattern, the nozzle unit position detecting unit determines an intersection point between the first edge and the second edge in each of the patch images, and determines respective positions of the plural nozzle units on the basis of positions of the determined intersection points.