Movable Redundant Nozzle Array for Inkjet Printhead
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Solution Overview
Problem
Ink jet printers face random nozzle contamination issues leading to image defects and reduced productivity in high-quality production applications, as existing systems are not effective in detecting and addressing nozzle failures in real-time, especially in single-pass high-speed systems.
Innovation Solution
The implementation of a dual printhead array system where a secondary array of nozzles is movable and aligned with a primary array, equipped with a detection system to identify defective nozzles and selectively activate backup nozzles, allowing for realignment and continued printing by translating the secondary array to maintain print quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single printhead array is used, then the device complexity is reduced, but the system reliability deteriorates due to random nozzle contamination and failures
Solution Approach 1:
A second redundant printhead array is positioned in standby readiness before failure occurs. The system proactively prepares backup nozzles that can be quickly activated when contamination or failure is detected in the primary array, eliminating the need for manual intervention or system shutdown.
Solution Approach 2:
The redundant printhead array serves as a protective buffer against nozzle failures. When the primary array experiences contamination or malfunction, the secondary array immediately compensates, cushioning the system against productivity losses and maintaining continuous operation without quality degradation.
2Reliability
If a redundant printhead array is added, then the system reliability is improved, but the device complexity increases
Solution Approach 1:
The system dynamically switches between the primary and secondary printhead arrays based on real-time nozzle performance. The controller continuously monitors droplet ejection quality and automatically activates backup nozzles in the second array when failures are detected, optimizing reliability while managing complexity through adaptive control.
Solution Approach 2:
The second printhead array is configured as a duplicate copy of the first array, with corresponding nozzles positioned to replace failed nozzles in the primary array. This copying approach provides redundancy without requiring fundamentally different hardware, managing complexity through replication of proven design.
3Productivity
If nozzle failures are not detected and addressed, then the productivity is maintained, but the manufacturing precision deteriorates due to image defects
Solution Approach 1:
The system implements real-time feedback monitoring of droplet ejection from each nozzle. When defects such as missing droplets, mispositioned droplets, or contaminated nozzles are detected, the controller immediately identifies the failed nozzle and switches to the corresponding backup nozzle in the second array, maintaining both productivity and precision simultaneously.
Solution Approach 2:
The system replaces mechanical cleaning or manual nozzle replacement with an automated electronic switching mechanism. When a nozzle fails, the controller electronically activates the corresponding backup nozzle in the second array, substituting mechanical maintenance operations with automated system reconfiguration that maintains continuous high-speed printing.
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 significantly extends the system life of ink jet printers by allowing continued operation despite nozzle failures, reducing the need for frequent maintenance and improving print quality through redundant nozzle functionality, with static redundancy offering 10-25 times longer maintenance intervals and movable redundancy providing an additional 2.0-2.5 times extension.
Implementation Method 1
detection system for detecting defective pixels in the printed output
Implementation Method 2
a means, responsive to said detecting means, for translating said secondary array of nozzles in relation to said primary array of nozzles along a path to a first position to realign the nozzles in said primary array of nozzles to nozzles in said secondary array of nozzles
Data Source
AI summary
There is provided a printhead for an ink jet printer, including a primary and a secondary array of nozzles in the printhead, the nozzles in the primary array of nozzles being in alignment with the nozzles in the secondary array of nozzles in a printing process direction; detection system for detecting defective nozzles in both the primary array of nozzles and in the secondary array of nozzles; a first mode operation having means for selectively activating nozzles in the secondary array of nozzles that are in alignment with defective nozzles in the primary array of nozzles; and a second mode of operation having means, responsive to the detecting means, for translating the secondary array of nozzles in relation to the primary array of nozzles along a path to a first position to realigned the nozzles in the primary array of nozzles to nozzles in the secondary array of nozzles if defective nozzles are aligned in both the primary and the secondary array of nozzles.