Inkjet Backpressure Capacitor Prevents Dripping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inkjet printing systems face issues with ink dripping due to lack of backpressure when the vacuum source is not maintained, and prior-art backpressure systems suffer from ink leakage caused by environmental changes, particularly temperature variations.
Innovation Solution
A backpressure capacitor system is introduced, where a vacuum system charges a capacitor to store potential energy, allowing it to maintain backpressure even when the vacuum is decoupled, using a U-shaped tank with a liquid interface between low-pressure and ambient gases, ensuring stable backpressure and preventing ink dripping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vacuum source is used to apply backpressure to prevent ink dripping, then ink dripping is prevented during operation, but the vacuum must be permanently operating and ink leaks when shutdown
Solution Approach 1:
The vacuum system performs preliminary action by creating backpressure and charging the capacitor before shutdown. The capacitor stores the potential energy (pressurized gas) in advance, so that when the vacuum system stops, the stored energy maintains backpressure and prevents ink dripping without continuous operation.
Solution Approach 2:
The capacitor acts as an intermediary between the vacuum system and the ink reservoir. It receives energy from the vacuum system and transfers it to maintain backpressure on the ink, allowing the vacuum system to be decoupled while still preventing ink leakage through the mediated stored energy.
2Stress or pressure
If elevation difference between ink tanks is used to generate backpressure, then backpressure is generated, but temperature changes cause ink volume expansion and ink leakage
Solution Approach 1:
The system uses pneumatic principles with a gas-filled capacitor to generate and store backpressure. The compressible gas in the capacitor provides a buffer that can absorb ink volume changes due to temperature expansion while maintaining sufficient backpressure, preventing both ink dripping and temperature-induced leakage.
Solution Approach 2:
The system changes the parameter of backpressure generation from static (elevation difference) to dynamic and controllable (pressurized gas in capacitor). This allows the backpressure to adapt to temperature changes and ink volume variations, maintaining effective pressure control under varying environmental conditions.
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 backpressure capacitor system effectively prevents ink dripping by maintaining sufficient backpressure without continuous vacuum operation, reducing maintenance costs and ink leakage, and allows for extended periods of vacuum system shutdown without ink loss.
Implementation Method 1
a vacuum system to charge a 'backpressure capacitor'
Implementation Method 2
the liquid to low-pressure-gas 'capacitor' interface rises relative to the liquid to ambient-gas interface so as to store potential energy
Implementation Method 3
Once charged, the backpressure capacitor can provide sufficient backpressure to the ink reservoirs to prevent dripping
Implementation Method 4
the capacitor interface falls; in the process, the volume of the confined low-pressure gas increases and its pressure decreases, limiting the fall of the capacitor interface
Data Source
AI summary
A vacuum source is coupled to an ink reservoir to establish a backpressure to prevent ink from dripping from a printhead. The vacuum source is also coupled to a backpressure capacitor so that a first liquid-gas interface rises to a first level. When the vacuum source is decoupled, the liquid-gas interface falls to a second level so as to maintain sufficient backpressure on said ink to prevent it from dripping from the inkjet printhead.