Electrode Pin Oxidation Compensation in Inkjet Liquid Level Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing pin remaining-amount detection method for liquid ejection systems, which uses metal electrode pins, suffers from reduced accuracy due to metal oxidation/reduction reactions, leading to incorrect liquid level detection and potential nozzle damage.
Innovation Solution
The method involves applying a voltage between electrode pins and adjusting the detection threshold values and resistance based on cumulative application time to account for oxidation, ensuring accurate liquid level detection by varying the determination threshold value and detection resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a current is repeatedly passed between electrode pins to detect liquid amount, then detection function is achieved, but metal oxidation/reduction reactions occur on electrode pin surfaces increasing electrical resistance and reducing detection accuracy
Solution Approach 1:
The patent applies periodic action by alternating the polarity of the voltage applied to the electrode pins. The control unit switches the voltage polarity between positive and negative, which prevents continuous unidirectional oxidation/reduction reactions. This periodic polarity reversal ensures that oxidation products formed during one half-cycle are reduced during the next half-cycle, maintaining stable electrical resistance and detection accuracy over time.
Solution Approach 2:
The patent changes the parameter of voltage polarity from constant to alternating. By dynamically changing the polarity parameter based on cumulative application time thresholds, the system prevents the accumulation of oxidation products on electrode pin surfaces. This parameter change maintains the electrical characteristics of the electrode pins and ensures consistent detection accuracy throughout the cartridge's operational life.
2Measurement precision
If determination threshold value is fixed, then detection system is simple, but detection accuracy decreases due to electrode pin oxidation over time
Solution Approach 1:
The patent applies dynamics by making the determination threshold value variable rather than fixed. The control unit dynamically adjusts the threshold value based on the cumulative application time of voltage to the electrode pins. As oxidation progresses over time, the threshold is adjusted to compensate for increased electrical resistance, maintaining accurate liquid level detection throughout the cartridge's operational life without requiring complex manual calibration.
Solution Approach 2:
The patent implements feedback by continuously monitoring the electrical response between electrode pins and adjusting the determination threshold based on cumulative application time. The system uses the observed changes in electrical characteristics due to oxidation to automatically adjust thresholds, creating a self-regulating detection system that maintains accuracy without external intervention.
3Speed
If voltage is applied continuously to detect liquid, then detection response is fast, but oxidation reactions accelerate reducing detection reliability
Solution Approach 1:
The patent applies periodic action by implementing cyclic voltage application with alternating polarity. The control unit applies voltage in positive and negative cycles, switching polarity based on cumulative application time. This periodic reversal prevents continuous oxidation accumulation while maintaining rapid detection response, as each cycle quickly establishes a stable electrical path for measurement.
Solution Approach 2:
The patent applies preliminary action by pre-establishing the polarity reversal strategy before oxidation significantly impacts detection. By planning the alternating polarity sequence based on cumulative application time thresholds, the system proactively prevents oxidation products from accumulating to levels that would compromise detection reliability, while maintaining fast response through optimized cycle timing.
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 improves the accuracy of liquid level detection, preventing premature ink tank replacement and nozzle damage by compensating for the effects of electrode pin oxidation.
Implementation Method 1
The liquid, such as ink, typically conducts electricity. As such, when the liquid storage chamber contains liquid (when the two electrode pins are in contact with the liquid), an electric signal applied to an electrode pin causes a current to flow between the electrode pins via the liquid.
Implementation Method 2
When a current is repeatedly passed in one direction between two electrode pins, one serving as the anode and the other serving as the cathode, with liquid present between the electrode pins, a metal oxidation/reduction reaction may occur on the surface of the electrode pins. That is, oxidation takes place on the surface of the anode electrode pin
Implementation Method 3
When a current is repeatedly passed in one direction between two electrode pins, one serving as the anode and the other serving as the cathode, with liquid present between the electrode pins, a metal oxidation/reduction reaction may occur on the surface of the electrode pins. That is, oxidation takes place on the surface of the anode electrode pin, while reduction takes place on the surface of the cathode electrode pin
Data Source
AI summary
An image recording apparatus includes: a liquid ejection cartridge unit that ejects ink droplets and includes a liquid chamber that stores liquid, and a first and a second electrode pins inserted in the liquid chamber; an application portion that applies a voltage between the first and the second electrode pins; and a detection portion that includes a detection resistance to which a voltage is applied by the application portion and detects a voltage value or a current value. When the application portion applies a voltage, the detection portion detects the voltage value or the current value so that the amount of liquid remaining in the liquid chamber is detected. At least one of the determination threshold value of the amount of the liquid in the liquid chamber, the applied voltage value, or the detection resistance value is set at intervals based on the cumulative application time of the voltage.