Head Unit Residual Vibration Signal Processing for Ejection State Determination
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Solution Overview
Problem
Existing liquid ejection apparatuses, such as inkjet printers, face limitations in determining the state of the ejection unit accurately, particularly due to insufficient detection of residual vibrations caused by the piezoelectric element drive signal.
Innovation Solution
The proposed solution involves a head unit with an ejection unit driven by a piezoelectric element, a waveform shaping circuit to process residual vibration signals, a temperature detection circuit to provide temperature information, and a determination circuit that uses both shaped residual vibration signals and temperature information to accurately determine the state of the ejection unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If only a simple residual vibration signal detection is used, then the device complexity is low, but the measurement precision of ejection unit state is insufficient
Solution Approach 1:
The waveform shaping circuit is divided into multiple functional blocks: a first waveform shaping circuit that performs initial signal processing, and a second waveform shaping circuit that performs additional processing. This segmentation allows complex signal processing to be achieved through modular stages, improving measurement precision while keeping each individual circuit block relatively simple.
Solution Approach 2:
A temperature detection circuit is introduced as an intermediary element that detects the temperature of the waveform shaping circuit and provides this information to the determination circuit. This intermediary measurement helps compensate for temperature-induced variations in the residual vibration signal, thereby improving determination accuracy without directly processing the signal itself.
2Measurement precision
If temperature compensation is added to improve measurement precision, then the determination accuracy improves, but the device complexity increases
Solution Approach 1:
The temperature detection circuit serves as an intermediary that measures the temperature of the waveform shaping circuit and provides this information to the determination circuit. This allows the system to compensate for temperature effects without directly processing the residual vibration signal through additional complex signal processing stages.
Solution Approach 2:
The system changes the measurement parameter from solely the residual vibration signal to include temperature information as well. By detecting temperature changes in the waveform shaping circuit and incorporating this parameter into the state determination, the system can compensate for temperature-induced variations and improve measurement precision.
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 configuration enhances the accuracy of determining the state of the ejection unit by effectively processing residual vibration signals and considering temperature factors, leading to improved operational reliability and print quality.
Implementation Method 1
an ejection unit that includes a piezoelectric element driven by a drive signal and that is configured to eject a liquid in accordance with drive of the piezoelectric element
Implementation Method 2
the waveform shaping circuit includes an amplifier circuit configured to amplify the first residual vibration signal
Data Source
AI summary
A head unit includes: an ejection unit that includes a piezoelectric element driven by a drive signal and that ejects a liquid; a waveform shaping circuit to which a first residual vibration signal corresponding to a residual vibration caused by the drive signal is input, and which outputs a second residual vibration signal; a temperature detection circuit that outputs a temperature information signal; and a determination circuit, wherein the waveform shaping circuit includes an amplifier circuit that amplifies the first residual vibration signal and a gain setting circuit, and outputs the second residual vibration signal based on a signal amplified by the amplifier circuit, the amplifier circuit and the gain setting circuit are configured as a single semiconductor device, and the determination circuit determines a state of the ejection unit based on the second residual vibration signal and the temperature information signal.