Inkjet Printer Pressure Sensor Fault Detection
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Solution Overview
Problem
In the field of industrial inkjet printing, expensive print heads are often replaced unnecessarily due to erroneous assumptions based on faulty pressure sensor measurements, leading to wasted time and resources.
Innovation Solution
A method that operates an inkjet printing machine in both printing and non-printing modes to accurately measure pressures in the supply and return lines using two pressure sensors, allowing for the verification of sensor accuracy and preventing unnecessary replacements of functioning components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pressure sensors are used to monitor ink pressure in the ink supply system, then the ink pressure can be measured and controlled, but false measurements from faulty sensors may lead to unnecessary replacement of expensive printheads
Solution Approach 1:
The system continuously monitors pressure differences between supply and return lines and provides feedback to detect sensor faults. When the pressure difference exceeds expected thresholds during non-printing operations, the system identifies potential sensor failures and alerts operators, preventing false diagnoses of printhead defects.
Solution Approach 2:
The patent introduces an intermediary diagnostic process that mediates between pressure sensor readings and printhead replacement decisions. By analyzing pressure data patterns and comparing them against operational states (printing vs. non-printing), the system acts as an intermediary layer that verifies whether measured pressure anomalies truly indicate printhead failure or sensor malfunction.
2Manufacturing precision
If printheads are replaced based on pressure sensor readings, then printing quality issues may be resolved, but time and resources are wasted replacing functioning components
Solution Approach 1:
The system performs preliminary diagnostic actions by analyzing pressure sensor data patterns before initiating printhead replacement. During non-printing operations, the system checks whether pressure readings are consistent with sensor malfunction rather than printhead failure, allowing operators to avoid unnecessary replacements and save valuable maintenance time.
3Stability of the object's composition
If the ink circulation system operates continuously, then ink pressure stability is maintained, but the system cannot distinguish between sensor faults and actual pressure issues
Solution Approach 1:
The system employs periodic diagnostic actions by switching between printing and non-printing operations. During non-printing periods, the ink circulation continues but at different flow rates, creating distinct pressure signatures that help differentiate between sensor faults and actual pressure problems. This periodic variation in operational state provides additional diagnostic information.
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 ensures that only defective print heads are replaced, saving time and costs by avoiding incorrect assumptions and maintaining accurate ink pressure settings, thus optimizing maintenance and reducing unnecessary expenses.
Implementation Method 1
the pressure of the ink in at least one of the two ink lines is measured with a pressure sensor
Data Source
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AI summary
A method according to the invention for operating an inkjet printing machine, which comprises a reservoir (3) for ink (30), a plurality of printheads (8) for ejecting ink droplets (31) and two ink lines (4), namely a feed line (4a) and a return line (4b), between the reservoir and the printheads, wherein the pressure of the ink in at least one of the two ink lines is measured with a pressure sensor (20, 21), is characterized in that the inkjet printing machine (1) is operated temporarily in a printing mode (M1, 41) and temporarily in a non-printing mode (M2, 42), and that in the non-printing mode the pressure p1 in the feed line (6a) is measured with a first pressure sensor (20) and the pressure p2 in the return line (6b) is measured with a second pressure sensor (21) (44).The invention advantageously makes it possible to avoid replacing components that actually function correctly, thus saving time and costs; and to avoid unwanted replacements due to incorrect assumptions, e.g., based on faulty measurements.