Liquid Ejecting Apparatus Viscosity Estimation via Residual Vibration Timing
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Solution Overview
Problem
In liquid ejecting apparatuses like ink jet printers, accurately measuring the viscosity of ink in compression chambers is challenging due to variations in residual vibration amplitude caused by noise in the driving signal, which affects image quality.
Innovation Solution
A liquid ejecting apparatus with a detection unit that measures residual vibration after the piezoelectric element is driven, a specification unit that determines the initial time for the residual vibration signal to reach its center amplitude, and an estimation unit that calculates the ink viscosity based on this time, ensuring accurate viscosity estimation regardless of noise-induced amplitude variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the amplitude of residual vibration is used to measure viscosity, then the measurement can be obtained, but the measurement precision deteriorates due to noise superposition causing amplitude variation
Solution Approach 1:
The patent changes the measurement parameter from amplitude (which varies due to noise) to time (specifically, the time from start to when the signal reaches center amplitude). This time parameter remains stable even when amplitude varies due to noise superposition, thereby resolving the contradiction between measurement precision and reliability
Solution Approach 2:
The patent replaces the traditional amplitude-based measurement approach with a time-based measurement approach. By substituting the measurement criterion from spatial (amplitude) to temporal (time duration), the system achieves reliable viscosity measurement independent of noise-induced amplitude variations
2Ease of operation
If noise is present on the driving signal, then the driving function is maintained, but the residual vibration amplitude varies making viscosity measurement difficult
Solution Approach 1:
The patent changes the detection parameter from amplitude to time. The time required for the residual vibration signal to reach its center amplitude remains consistent even when noise causes amplitude variations, thereby making detection easier and more reliable without requiring a cleaner driving signal
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 solution allows for precise estimation of ink viscosity, improving image quality by stabilizing the residual vibration measurement and reducing noise interference, thus enhancing the reliability of the ink discharge process.
Implementation Method 1
a piezoelectric element that is driven by a driving signal
Implementation Method 2
a detection unit detecting residual vibration occurring in the discharge portion, in a detection period after the piezoelectric element is driven
Data Source
AI summary
A liquid ejecting apparatus includes a discharge portion provided with a piezoelectric element that is driven by a driving signal and a compression chamber that discharges a liquid from a nozzle according to the driving of the piezoelectric element, a detection unit detecting residual vibration occurring in the discharge portion, in a detection period after the piezoelectric element is driven and outputting a residual vibration signal indicating a waveform of the residual vibration, a specification unit specifying an initial time from a start time when the detection period starts to a reference time when a residual vibration signal becomes a signal level of a center of an amplitude after the start time of the detection period, and an estimation unit estimating a viscosity of the liquid in the compression chamber, based on the initial time.