Liquid Ejection Head Threshold Setting for Determination Accuracy
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Solution Overview
Problem
Existing liquid ejection head systems face challenges in accurately determining the ejection state due to manufacturing variability and sensitivity changes in temperature detection elements, leading to potential ejection failures and reduced accuracy in determining the ejection state.
Innovation Solution
A liquid ejection apparatus and ejection state determination apparatus that utilize a heat generating resistance element, temperature detection element, and ejection port, with a threshold setting unit that estimates a second output value based on multiple energy levels to determine the ejection state by comparing output values with a set determination threshold, thereby reducing the influence of manufacturing variability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed threshold is set for ejection state determination using temperature detection elements, then the determination process is simple and fast, but the accuracy deteriorates due to manufacturing variability and sensitivity changes in temperature detection elements
Solution Approach 1:
The patent applies preliminary action by measuring the relationship between application energy and detection output values in advance under non-ejection conditions, storing this data for later use. This pre-measured data is then used to estimate the second output value without requiring real-time complex measurements, thus improving accuracy while maintaining operational simplicity.
Solution Approach 2:
The patent implements feedback by using the measured relationship between application energy and detection output to dynamically estimate the second output value based on the actually applied energy. This feedback mechanism allows the determination threshold to adapt to manufacturing variability and sensitivity changes, improving measurement precision without requiring complex real-time adjustments.
2Ease of manufacture
If the determination threshold is set by lowering a fixed value from the first output value, then the threshold setting is simple, but the accuracy of ejection state determination deteriorates due to variability in temperature detection element outputs
Solution Approach 1:
The patent applies parameter changes by transitioning from a fixed threshold value to a dynamically estimated second output value that varies based on the actually applied energy. This allows the threshold to adapt to different operating conditions and manufacturing variations, improving accuracy while maintaining ease of implementation through pre-measured data relationships.
3Measurement precision
If energy levels are increased to improve detection accuracy, then the ejection state can be determined more accurately, but the risk of damaging the liquid ejection head increases
Solution Approach 1:
The patent applies partial action by using multiple levels of application energy that are all below the damage threshold, rather than using a single high energy level. By measuring at multiple lower energy levels and using the relationship between energy and output to estimate the second output value, the system achieves accurate detection without exposing the liquid ejection head to damaging heat levels.
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 enables accurate and reliable determination of the ejection state, minimizing the impact of manufacturing variability and ensuring proper functioning of the liquid ejection head by setting a proper threshold for ejection state detection.
Implementation Method 1
heat is applied to liquid to cause film boiling, and the force of the bubble generation is utilized to eject the liquid from ejection ports
Implementation Method 2
temperature detection element that detects temperature corresponding to the heat generating resistance element
Data Source
AI summary
In order to make it less likely for the accuracy of determination of the ejection state of a liquid ejection head to be low, a liquid ejection apparatus sets a determination threshold for determining an ejection state of the liquid ejection head using first energy, the determination threshold being set based on a first output value outputted from the output unit in an event where the heat generating resistance element is driven with the first energy in an ejection state in which the liquid is ejected from an ejection port and a second output value estimated to be outputted from the output unit assuming the heat generating resistance element is driven with the first energy in a non-ejection state in which the liquid is not ejected.