Liquid Ejection Apparatus Ink Leakage Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid ejection apparatuses face challenges in simultaneously discharging ink from all ejection openings due to varying ink-discharge resistances, leading to unnecessary ink discharge and potential leakage from the ejection openings.
Innovation Solution
A liquid ejection apparatus that adjusts channel resistance values and controls the supply device to apply a high pressure from the start of liquid discharge, using a controller to manage the unit-time supply amount and air communication with the tank, preventing unnecessary ink leakage and ensuring efficient discharge of air bubbles and foreign matters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the ink pressure is increased to discharge ink from all ejection openings simultaneously, then the cleaning efficiency is improved, but the ink discharge resistance variation causes sequential discharge from individual openings leading to unnecessary ink consumption
Solution Approach 1:
The patent applies local quality by providing individual pressure control for each ink channel through separate pressure control units. Each channel can be pressurized independently according to its specific discharge resistance characteristics, allowing simultaneous discharge from all ejection openings without forcing sequential discharge that wastes ink.
Solution Approach 2:
The patent changes the pressure parameter dynamically for each channel based on discharge resistance measurements. By adjusting pressure levels individually for each channel, the system achieves simultaneous ink discharge from all openings while preventing the sequential discharge problem that causes unnecessary ink consumption.
2Stability of the object's composition
If the pump operates for a relatively long time to reach desired ink pressure, then the pressure stabilization is improved, but the discharge timing becomes delayed causing sequential discharge from openings with lower resistance
Solution Approach 1:
The patent performs preliminary measurements of ink discharge resistance for each channel before the actual discharge operation. Based on these pre-obtained resistance values, the system calculates and sets the appropriate pressure levels in advance, eliminating the need for prolonged pump operation to stabilize pressure and enabling immediate simultaneous discharge from all openings.
Solution Approach 2:
The patent implements feedback control by measuring the ink discharge resistance of each channel and using this information to adjust the pressure control parameters. This closed-loop control ensures that each channel reaches the desired pressure level simultaneously without unnecessary delay, maintaining both pressure stability and timely discharge.
3Productivity
If ink is discharged from ejection openings during cleaning, then the channel resistance is reduced, but the discharged ink adheres to defining portions lowering meniscus withstanding pressure and causing leakage
Solution Approach 1:
The patent applies dynamics by controlling the pressure and flow rate of ink during the discharge process. By dynamically adjusting these parameters, the system discharges ink efficiently to reduce channel resistance while simultaneously preventing excessive ink adhesion to defining portions, thereby maintaining meniscus withstanding pressure and preventing leakage.
4Productivity
If the unit-time supply amount is high during liquid discharge control, then the discharge efficiency is improved, but the meniscus withstanding pressure is lowered making leakage more likely after discharge
Solution Approach 1:
The patent implements periodic action by controlling the pump operation in distinct phases: a high-pressure discharge phase for efficient ink removal, followed by a low-pressure maintenance phase to preserve meniscus withstanding pressure and prevent leakage. This temporal separation of functions achieves both high discharge efficiency and reliable leakage prevention.
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
The apparatus efficiently discharges ink and air bubbles from all ejection openings while preventing unnecessary ink consumption and leakage, ensuring reliable operation even after the discharge is completed.
Implementation Method 1
starting the operation of the pump to pressurize the ink in the ink channels for a predetermined length of time, thereby discharging the ink from nozzles
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A liquid ejection apparatus (101) including: a liquid ejection head (1) including: an inlet opening (72a) into which liquid flows; an outlet opening (73a) from which the liquid having flowed into the inlet opening flows; an inside channel (72,73) communicating the inlet opening and the outlet opening with each other; and a plurality of ejection openings (108) through which is ejected the liquid having flowed through a plurality of individual channels (132) that are branched from the inside channel; a tank (80) storing the liquid to be supplied to the liquid ejection head; a supply channel (82) communicating the tank and the inlet opening with each other; a return channel (83) communicating the tank and the outlet opening with each other; a supply device (86) configured to supply the liquid in the tank to the inside channel via the supply channel; an adjusting device (87) configured to adjust a channel resistance value of the return channel between a predetermined minimum value and a predetermined maximum value; and a controller (16) configured to control the supply device and the adjusting device, wherein the controller is configured to start a liquid circulation control for circulating the liquid through the supply channel, the inside channel, and the return channel in order by controlling (i) the adjusting device such that the channel resistance value is less than the predetermined maximum value and (ii) the supply device to supply the liquid into the inside channel, wherein, when the liquid is circulated by the liquid circulation control, the controller starts a liquid discharge control for discharging the liquid from the plurality of the ejection openings by increasing the channel resistance value to a value larger than the channel resistance value in the liquid circulation control, wherein, when the liquid is discharged by the liquid discharge control, the controller starts a liquid-discharge stopping control for stopping the discharge of the liquid from the plurality of the ejection openings, by decreasing the channel resistance value to a value less than the channel resistance value in the liquid discharge control, and wherein the controller is configured to control the supply device such that a unit-time supply amount that is an amount of the liquid supplied to the inside channel per unit time at a time when the discharge of the liquid from the plurality of the ejection openings is stopped by the liquid-discharge stopping control is less than a unit-time supply amount in the liquid circulation control.