Ink-jet Printer Viscosity-Based Drive Voltage Control
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Solution Overview
Problem
Ink-jet printers face issues with ink viscosity changes due to settling and evaporation differences among various ink colors, leading to increased friction and mistaken jetting when trying to maintain optimal jetting conditions, especially when pigment inks settle and thicken, causing viscosity to rise in nozzles.
Innovation Solution
An ink-jet printer system with a controller that estimates ink viscosity and adjusts drive voltage and meniscus vibration signals for each nozzle, using different meniscus vibration signals based on viscosity levels to prevent thickening and mistaken jetting, by outputting specific signals corresponding to the drive voltage generated by the power supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a common drive voltage is applied to all nozzles to maintain optimal jetting conditions, then jetting performance is improved, but mistaken jetting occurs when ink viscosity increases due to settling and evaporation
Solution Approach 1:
The patent applies different drive voltages to different nozzles based on their individual ink viscosity conditions. The controller adjusts the drive voltage for each nozzle independently according to the estimated viscosity of ink in that specific nozzle, allowing optimal jetting conditions for each nozzle while preventing mistaken jetting in nozzles with higher viscosity ink.
Solution Approach 2:
The patent changes the drive voltage parameter dynamically based on ink viscosity estimates. The controller modifies the drive voltage level for each nozzle according to the estimated viscosity of ink in that nozzle, adjusting the electrical parameter to match the physical state of the ink and prevent mistaken jetting.
2Reliability
If drive voltage is increased to prevent ink thickening in high viscosity nozzles, then jetting reliability is improved, but energy consumption increases
Solution Approach 1:
The patent applies increased drive voltage only to specific nozzles where ink viscosity is estimated to be high, rather than increasing voltage for all nozzles. This localized approach maintains jetting reliability for affected nozzles while minimizing unnecessary energy consumption in nozzles with normal viscosity ink.
Solution Approach 2:
The patent applies excessive drive voltage (higher than normal) only partially to nozzles that require it based on viscosity estimation. The controller determines which nozzles need the excessive voltage based on estimated ink viscosity and applies it only to those specific nozzles, avoiding excessive energy consumption in nozzles that don't need it.
3Object-generated harmful factors
If different drive voltages are applied to different nozzles based on viscosity estimation, then mistaken jetting is prevented, but device complexity increases
Solution Approach 1:
The patent uses a feedback mechanism where the controller estimates ink viscosity in each nozzle based on stored viscosity information and adjusts the drive voltage accordingly. The controller receives viscosity data, processes it to determine appropriate drive voltage levels, and applies the adjusted voltage to prevent mistaken jetting, creating a closed-loop control system.
Solution Approach 2:
The system performs self-adjustment by automatically estimating ink viscosity and modifying drive voltages without external intervention. The controller monitors ink conditions and autonomously adjusts operating parameters to prevent mistaken jetting, reducing the need for manual calibration or complex external control systems.
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
Effectively suppresses the risk of ink becoming un-jettable due to thickening and reduces the likelihood of mistaken jetting by adjusting energy imparted to inks based on viscosity levels, ensuring consistent printing performance across different ink colors.
Implementation Method 1
a piezoelectric element (a drive element), are provided for each ink color. Moreover, the piezoelectric element deforms when applied with a drive waveform of a certain voltage level, whereby ink is jetted from the nozzle
Implementation Method 2
a preliminary waveform (a meniscus vibration signal) for vibrating a meniscus of ink in the nozzle without jetting the ink, is applied to the piezoelectric element at a certain voltage level, with an object of suppressing thickening of the ink in the nozzle
Data Source
AI summary
In an inkjet printer, when an estimated viscosity of a first ink in a first nozzle is less than a threshold value, a power supply generates a first drive voltage, and when the estimated viscosity of the first ink is the threshold value or more, the power supply generates a second drive voltage higher than the first drive voltage. Moreover, at a time of vibrating a meniscus of a second ink in a second nozzle, when the first drive voltage is generated by the power supply, there is output to a drive element a first meniscus vibration signal, and when the second drive voltage is generated, there is output a second meniscus vibration signal by which energy imparted to the second ink by the drive element when applied to the drive element at an identical voltage level will be smaller compared to the first meniscus vibration signal.