Inkjet Printhead Nozzle Discharge Judgment via Dynamic Threshold
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional inkjet printing systems face challenges in accurately judging ink discharge status due to changes in temperature detection element sensitivity caused by heat generation and protection film deterioration, leading to incorrect judgment of nozzle discharge failures.
Innovation Solution
A printing apparatus and method that uses a selection unit to choose nozzles for inspection, drives heaters with different pulses, and adjusts threshold values based on temperature detection results to correctly judge ink discharge status, even with changing sensitivity of temperature detection elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature detection element is provided immediately below a print element to detect ink discharge status, then the sensitivity of temperature detection is improved, but the sensitivity of the temperature detection element changes over time due to heat generation and protection film deterioration
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the threshold value for temperature detection based on the accumulated number of ink discharge operations. As the print element undergoes repeated use, the threshold is modified to compensate for sensitivity drift in the temperature detection element, thereby maintaining accurate judgment of ink discharge status throughout the device's operational life
Solution Approach 2:
The patent implements feedback by continuously monitoring the temperature detection results and using this information to adjust the threshold value. The system accumulates operational data and uses it to refine the threshold, creating a closed-loop control mechanism that adapts to changing conditions and maintains reliable discharge status judgment
2Productivity
If the threshold value for temperature detection is fixed, then the judgment process is simple and fast, but incorrect judgment occurs when temperature detection element sensitivity changes due to use
Solution Approach 1:
The patent applies dynamics by transforming the static threshold value into a dynamic parameter that changes based on operational conditions. The threshold is no longer fixed but adapts according to the accumulated number of ink discharge operations, allowing the system to maintain measurement precision while preserving the simplicity and speed of the judgment process
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
Enables accurate judgment of ink discharge status, preventing incorrect assessments and ensuring reliable image quality by adapting to changes in temperature detection element sensitivity.
Implementation Method 1
a plurality of heaters respectively provided in the plurality of nozzles and each configured to heat the ink
Implementation Method 2
a plurality of temperature detection elements provided in correspondence with the plurality of heaters
Data Source
AI summary
A printing apparatus, which uses a printhead including a circuit configured to inspect an ink discharge status of a selected nozzle using a temperature detection element, causes the printhead to inspect the ink discharge status by changing a threshold value for judging a detection result of the temperature detection element, in order to judge the ink discharge status in a state in which a heater in the selected nozzle is driven by each of a first pulse and a second pulse whose waveform is different from that of the first pulse, obtains first information about a change point where a judgment result obtained by the first pulse changes, and second information about a change point where a judgment result obtained by the second pulse changes, and sets the threshold value, based on the first and second information.