Liquid Ejecting Apparatus Foreign Matter Detection
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Solution Overview
Problem
Existing liquid ejecting apparatuses, such as ink jet printers, face challenges in accurately determining whether foreign matter like paper dust is adhering to nozzles due to similar residual vibration waveforms for both adhered and unadhered conditions, leading to potential image quality degradation.
Innovation Solution
A liquid ejecting apparatus with a generation unit that generates a driving signal for a piezoelectric element and a detection unit to analyze residual vibrations, utilizing a specific waveform pattern with varying potentials during the driving and detection periods to differentiate between normal and abnormal discharge states, including adhered foreign matter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a simple driving signal is used to eject liquid, then the device operation is simple, but the accuracy of detecting foreign matter adherence is insufficient because residual vibration waveforms are similar for both adhered and unadhered conditions
Solution Approach 1:
The driving signal is divided into multiple distinct periods (first period, second period, third period, and detection period) with different potential levels. This segmentation allows the system to excite the discharge portion in a controlled manner and capture residual vibration characteristics at different stages, enabling accurate differentiation between normal and abnormal discharge states through comparative analysis of vibration waveforms from each period.
Solution Approach 2:
The driving signal employs periodic potential changes with specific patterns across four distinct periods. By applying periodic voltage variations and analyzing the resulting residual vibrations in each period, the system can identify characteristic waveform patterns that indicate foreign matter adherence, thereby improving detection accuracy through rhythmic excitation and response analysis.
2Measurement precision
If residual vibration detection is performed after liquid ejection, then foreign matter adherence can be identified, but the detection accuracy is insufficient when residual vibration waveforms are substantially the same regardless of foreign matter presence
Solution Approach 1:
The system dynamically adjusts the potential levels across different periods of the driving signal (first potential, second potential, third potential, and detection potential) to create varying excitation conditions. This dynamic approach allows the residual vibration waveforms to exhibit distinct characteristics depending on the discharge state, enabling reliable differentiation between normal operation and foreign matter adherence through waveform comparison across multiple dynamic states.
Solution Approach 2:
The driving signal utilizes parameter changes by varying the potential levels across four distinct periods. By changing the voltage parameters systematically and analyzing how residual vibrations respond to these parameter variations, the system can identify subtle differences in waveform characteristics that indicate foreign matter presence, thereby improving both detection accuracy and determination reliability.
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 enhances the accuracy of determining foreign matter adherence, thereby maintaining image quality by distinguishing between normal and abnormal discharge states based on residual vibration analysis.
Implementation Method 1
a piezoelectric element that is driven by the driving signal and a pressure chamber that discharges a liquid from a nozzle according to the driving of the piezoelectric element
Implementation Method 2
a detection unit that detects residual vibration occurring in the discharge portion, in a detection period after a driving period during which the piezoelectric element is driven by the driving signal
Data Source
AI summary
A liquid ejecting apparatus includes a generation unit that generates a driving signal, a discharge portion including a piezoelectric element that is driven by the driving signal, and a detection unit that detects residual vibration occurring in the discharge portion, in a detection period after a driving period during which the piezoelectric element is driven by the driving signal, in which the generation unit maintains a potential of the driving signal at a first potential in a first period, maintains the potential of the driving signal at a second potential in a second period, maintains the potential of the driving signal at a third potential in a third period, and maintains the potential of the driving signal at a detection potential in the detection period, the first potential is a potential between the second potential and the third potential, and the detection potential is a potential between the first potential and the second potential.