Asymmetric Ink Channel Structure for Bubble Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ink-jet heads with bent ink channels face challenges in preventing bubbles from staying, leading to non-discharge or discharge failure due to insufficient bubble prevention mechanisms.
Innovation Solution
A liquid channel structure featuring a first channel, a second channel, and a communication channel where the center line of the communication channel deviates from the center lines of the first and second channels, and the channel area of the communication channel is larger than the channel areas of the first and second channels, generating a swirling flow to prevent bubbles from staying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the ink channel has a bent portion to save space or change flow direction, then the channel can be compacted, but bubbles easily stay in the bent portion and are not easily discharged
Solution Approach 1:
The communication channel is designed with an asymmetric cross-sectional shape where the liquid flow cross-sectional area is larger than the air bubble flow cross-sectional area. This asymmetry causes liquid to flow faster than air bubbles, creating a velocity difference that prevents bubbles from staying in bent portions and facilitates their discharge.
Solution Approach 2:
The patent changes the flow dynamics parameters by creating a velocity difference between liquid and air bubbles through the asymmetric channel design. The liquid flow velocity is increased relative to air bubble velocity, transforming the flow regime to prevent bubble accumulation in bent portions.
2Device complexity
If a conventional ink channel structure is used, then the structure is simple, but bubbles remain in bent portions causing non-discharge or discharge failure
Solution Approach 1:
The patent applies local quality by designing different cross-sectional areas for liquid and air flow within the same communication channel. The channel provides different flow characteristics for different substances (liquid vs. air bubbles) at the same location, optimizing each flow type's behavior without requiring separate channels.
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 proposed structure effectively prevents bubbles from staying in the connection portions, ensuring smooth liquid flow and reliable inkjetting by generating a swirling flow, which enhances the discharge efficiency and reduces the need for frequent purging.
Implementation Method 1
a center line (C3) of the communication channel deviates from a center line (C1 or C2) of at least one of the first and the second channels in a width direction of one of the first and second channels; and a channel area (A3) of the communication channel is larger than a channel area (A1) of the first channel at the end portion (16d) thereof and a channel area (A2) of the second channel at an end portion (20d) thereof. Therefore, a swirling flow is generated at a connection portion (16a, 20a)
Data Source
AI summary
An ink channel in a channel unit includes a pressure chamber and a throttle channel in which ink flows along different planes and a communication hole which communicates the pressure chamber and the throttle channel. A center line of the communication hole deviates from a center line of the pressure chamber in a width direction of the pressure chamber, and also deviates from a center line of the throttle channel in a width direction of the throttle channel. Consequently, a swirling flow is generated in connection portions at which the pressure chamber and the throttle channel are connected to the communication hole, thereby effectively preventing bubbles from staying.