Liquid Ejecting Apparatus Upstream Pressure Control for Meniscus Stability
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Solution Overview
Problem
Existing liquid ejecting apparatuses face challenges in increasing the flow amount of liquid while minimizing the risk of meniscus breakage in the nozzle, particularly when negative pressure on the downstream side of the valve element is increased to enhance flow, leading to higher pressure within the nozzle.
Innovation Solution
The method involves increasing the pressure on the upstream side of the valve element when a larger flow amount is required, which reduces the negative pressure increase in the nozzle, and using a flexible film to open the valve element based on pressure differences or external forces to control the flow, allowing the apparatus to operate with a cap separated from the liquid ejecting head to prevent meniscus breakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the negative pressure on the downstream side of the valve element is increased to increase the flow amount of liquid flow, then the flow amount increases, but the negative pressure in the nozzle increases causing meniscus breakage
Solution Approach 1:
The patent changes the pressure parameter distribution by increasing the pressure on the upstream side of the valve element when larger flow amounts are required. This compensates for the increased negative pressure in the nozzle, preventing meniscus breakage while achieving the desired flow increase. The control method dynamically adjusts the upstream pressure based on flow requirements.
2Ease of operation
If the valve element is opened based on negative pressure on the downstream side and atmospheric pressure, then the liquid flow can be generated, but the flow amount cannot be increased without causing meniscus breakage
Solution Approach 1:
The patent makes the valve element opening control dynamic by responding to both negative pressure on the downstream side and atmospheric pressure conditions. The valve element opens automatically when the pressure differential exceeds a threshold, allowing the system to adapt to varying flow requirements while maintaining meniscus integrity through coordinated pressure management.
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 approach effectively increases the flow amount while minimizing meniscus breakage and allows for stable operation by adjusting pressures stepwise to manage stagnation and bubble discharge within the liquid ejecting head.
Implementation Method 1
the valve element is opened by deformation of the flexible film according to pressure difference between a pressure on the first surface and a pressure on the second surface
Implementation Method 2
the flexible film has a first surface that constitutes part of the inflow channel downstream of the valve element and a second surface opposite to the first surface, and the valve element is opened by deformation of the flexible film
Implementation Method 3
opening the inflow channel by opening the valve element in accordance with a negative pressure on a downstream side of the valve element to generate a liquid flow from the inflow channel to the outflow channel through the inner space
Implementation Method 4
generate a liquid flow from the inflow channel to the outflow channel through the inner space
Implementation Method 5
A pressure on an upstream side of the valve element is increased more in a case where a flow amount of the liquid flow is larger
Implementation Method 6
the increase in the negative pressure in the nozzle can be reduced because the pressure on the upstream side of the valve element is increased more
Data Source
AI summary
A control method of a liquid ejecting apparatus is provided. The liquid ejecting apparatus includes a liquid ejecting head that has an inner space in which a liquid flows and that ejects the liquid in the inner space through a nozzle, an inflow channel through which the liquid flows into the inner space, an outflow channel through which the liquid in the inner space flows out, and a valve element that opens and closes the inflow channel. The control method includes opening the inflow channel by opening the valve element in accordance with a negative pressure on a downstream side of the valve element to generate a liquid flow from the inflow channel to the outflow channel through the inner space. A pressure on an upstream side of the valve element is increased more in a case where a flow amount of the liquid flow is larger.