Bidirectional Inkjet Registration Using Multi-Purpose Sensor Feedback
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Solution Overview
Problem
Existing serial-type printing technologies face challenges in achieving high linear quality during bidirectional printing due to misalignment of ink droplet landing positions, despite registration adjustment methods like those disclosed in Japanese Patent Laid-Open No. 2010-241148.
Innovation Solution
A multi-purpose sensor is employed to detect density and distance, enabling precise registration adjustment by measuring ink patterns and adjusting ejection timing, particularly in bidirectional printing, using a multi-purpose sensor to optimize landing positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If bidirectional printing is conducted in a serial-type printing apparatus, then productivity is improved by reducing idle time, but manufacturing precision deteriorates due to misalignment of ink droplet landing positions
Solution Approach 1:
The system performs preliminary registration adjustment by printing test patterns and measuring their positions before actual printing. The control unit calculates correction values based on measured deviations and applies these corrections to the ejection timing, ensuring that landing positions are aligned before production printing begins.
Solution Approach 2:
The system uses a sensor to detect the actual landing positions of ink droplets and feeds this information back to the control unit. The control unit then adjusts the ejection timing based on the detected deviations, creating a closed-loop control system that continuously optimizes landing position alignment during bidirectional printing.
2Manufacturing precision
If registration adjustment is performed to align landing positions, then manufacturing precision is improved, but device complexity increases due to additional sensors and control mechanisms
Solution Approach 1:
The patent employs a multi-purpose sensor that serves multiple functions: it detects the landing positions of ink droplets for registration adjustment, measures the distance between the printing head and printing medium, and can detect ink density. This multi-functionality reduces the need for separate dedicated sensors, thereby limiting the increase in device complexity.
Solution Approach 2:
The system uses the printing apparatus itself to perform registration adjustment by printing test patterns and using its own sensor to measure their positions. This self-contained approach eliminates the need for external calibration equipment or additional complex measurement systems, allowing the apparatus to adjust its own alignment.
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 approach enhances linear quality by aligning ink droplet landing positions, improving image quality in bidirectional printing regardless of head height or scan speed variations.
Implementation Method 1
A multi-purpose sensor is employed to detect density and distance
Implementation Method 2
A multi-purpose sensor is employed to detect density and distance
Data Source
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AI summary
A printing apparatus (200) controls an ejection timing of a printing unit (5) such that a first distance becomes shorter than a second distance, where the first and second distances are distances in a scanning direction between a landing position at which an ink droplet lands on a printing medium (P) in a case where the printing unit (5) scans in a first direction and a landing position at which an ink droplet lands on the printing medium (P) in a case where the printing unit (5) scans in a second direction in first and second printing modes, respectively.