Ink Pressure Regulator Bubble Point Laplace Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inkjet printer systems face challenges in maintaining a stable negative hydrostatic pressure within a narrow pressure range, especially at high ink flow rates, due to limitations in manufacturing tolerances and hydraulic drag issues with foam inserts and mechanical pressure regulators.
Innovation Solution
A pressure regulator system that utilizes a bubble outlet with a critical dimension to control Laplace pressure, minimizing flow resistance and ink losses, and incorporates a laminated air intake plate with a bubble vent to manage air bubbles and maintain optimal hydrostatic pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If foam inserts are used to generate negative ink pressure, then negative pressure is established, but hydraulic drag causes ink flow starvation at high print speeds
Solution Approach 1:
The invention extracts the pressure-regulating function from the foam insert itself and relocates it to a dedicated bubble outlet positioned at the ink-air interface. This separates the ink delivery path from the pressure control mechanism, eliminating hydraulic drag on the ink flow while maintaining negative pressure through controlled bubble formation.
Solution Approach 2:
The invention introduces an air bubble as an intermediary element at the ink-air interface. The bubble outlet controls bubble formation to regulate negative pressure, while the tortuous air channel provides a separate pathway for air supply that does not impede ink flow, acting as a mediator between pressure control and flow rate requirements.
2Stress or pressure
If mechanical pressure regulators with springs are used, then negative pressure is generated, but manufacturing tolerances must be extremely tight
Solution Approach 1:
The invention replaces the mechanical spring-based pressure regulation system with a surface tension-based bubble point pressure mechanism. The critical dimension of the bubble outlet controls bubble formation pressure through capillary effects, eliminating the need for precision-machined springs and complex mechanical assemblies.
Solution Approach 2:
The invention changes the pressure control mechanism from mechanical force balance to surface tension-dominated bubble point pressure. By controlling the critical dimension (diameter) of the bubble outlet, the system achieves pressure regulation through capillary pressure effects, which are less sensitive to manufacturing variations than mechanical spring systems.
3Stress or pressure
If bubble outlet critical dimension is reduced to control Laplace pressure, then pressure regulation improves, but flow resistance increases
Solution Approach 1:
The invention segments the air supply function into two separate pathways: a tortuous air channel for air intake that minimizes ink contact, and a bubble outlet for controlled bubble formation. This segmentation allows the bubble outlet to be optimized for pressure control while the air channel is optimized for low-resistance air supply, preventing flow resistance issues.
Solution Approach 2:
The tortuous air channel acts as an intermediary structure that guides air to the bubble outlet while minimizing ink losses. The channel's geometry (larger dimensions than the bubble outlet) ensures air can reach the interface without creating excessive flow resistance, while the tortuous path prevents direct ink access to the air inlet.
4Object-affected harmful factors
If ink pressure is increased to prevent nozzle leakage, then ink flooding occurs during inactivity, but if pressure is decreased to prevent flooding, then nozzle leakage increases
Solution Approach 1:
The bubble point pressure mechanism provides automatic feedback control of ink pressure. When ink pressure drops below the bubble point pressure, air bubbles form through the bubble outlet, increasing the negative pressure back to the bubble point level. This self-regulating mechanism maintains pressure within the optimal range, preventing both flooding and leakage without manual intervention.
Solution Approach 2:
The system uses the inkjet printhead's own operation to maintain pressure regulation. During printing, ink withdrawal maintains negative pressure at the bubble point. When printing stops and pressure rises, the bubble outlet automatically forms bubbles to restore negative pressure, making the system self-regulating without external control mechanisms.
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 solution effectively regulates hydrostatic pressure, ensuring consistent ink flow and minimizing ink leakage and image defects, even at high print speeds, without requiring precise manufacturing tolerances or complex mechanical components.
Implementation Method 1
said bubble outlet being dimensioned to control a Laplace pressure of air bubbles drawn into said chamber as result of supplying ink to the printhead, thereby regulating a hydrostatic pressure of the ink
Implementation Method 2
an air channel connecting the air inlet and the bubble outlet
Data Source
Figure 1~2
Figure 3A~3B
Figure 4~5
AI summary
An ink pressure regulator for regulating a hydrostatic pressure of ink supplied to an inkjet printhead, said regulator comprising: an ink chamber having an ink outlet for fluid communication with the printhead via an ink line; an air inlet open to atmosphere; a bubble outlet for bubbling air bubbles into the chamber, each air bubble comprising an air cavity trapped inside a film or a body of ink; and an air channel connecting the air inlet and the bubble outlet, wherein said bubble outlet is dimensioned to control a Laplace pressure of air bubbles drawn into said chamber as result of supplying ink to the printhead, thereby regulating a hydrostatic pressure of the ink.