Liquid Discharge Head Connecting Channel Cross-Sectional Area Design
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Solution Overview
Problem
Existing liquid droplet generators face issues with satellites and mists adhering to nozzles, leading to discharge failures and deteriorated image quality, especially when the pulse width of the main pulse is set at Acoustic Length (AL), making it difficult to suppress satellites and mists without increasing the pulse width and compromising high-frequency driving.
Innovation Solution
The liquid discharge head is designed with a connecting channel having multiple portions with different cross-sectional areas, where the first portion adjacent to the pressure chamber has the smallest cross-sectional area, and the relationships S1≤0.3×S0 and S1≤0.7×S2 are maintained, mitigating pressure fluctuations and suppressing satellites and mists without lengthening the main pulse width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pulse width of the main pulse is set at Acoustic Length (AL) to enhance discharge pressure, then discharge efficiency is improved, but satellites and mists cannot be suppressed effectively
Solution Approach 1:
The connecting channel is divided into multiple portions with different cross-sectional areas, creating a segmented structure that progressively controls liquid flow. This segmentation allows the liquid to be discharged in a controlled manner, suppressing satellite droplets and mists while maintaining efficient discharge at AL pulse width.
Solution Approach 2:
Different portions of the connecting channel are given different cross-sectional areas to create localized flow control zones. The first portion has the smallest area to suppress satellites, while subsequent portions have progressively larger areas to maintain discharge efficiency, applying local quality variations to solve the contradiction.
2Object-generated harmful factors
If the pulse width of the main pulse is increased to suppress satellites and mists, then satellite suppression is improved, but the entire pulse cycle width increases making high frequency driving impossible
Solution Approach 1:
The connecting channel is divided into multiple portions with different cross-sectional areas, creating a segmented structure that progressively controls liquid flow. This segmentation allows the liquid to be discharged in a controlled manner, suppressing satellite droplets and mists while maintaining efficient discharge at AL pulse width.
Solution Approach 2:
The cross-sectional area parameter of the connecting channel is changed along its length, with the first portion having the smallest area and subsequent portions having progressively larger areas. This parameter change enables satellite suppression without requiring increased pulse width, maintaining high frequency driving capability.
3Device complexity
If a single uniform cross-sectional area is used in the connecting channel, then device complexity is reduced, but pressure fluctuation during discharge increases
Solution Approach 1:
Different portions of the connecting channel are given different cross-sectional areas to create localized flow control zones. The first portion has the smallest area to suppress satellites, while subsequent portions have progressively larger areas to maintain discharge efficiency, applying local quality variations to solve the contradiction.
Solution Approach 2:
The connecting channel structure transitions from a static uniform design to a dynamic gradient structure where the cross-sectional area changes progressively. This dynamic design adapts to the changing pressure conditions during discharge, stabilizing pressure fluctuations while maintaining reasonable structural complexity.
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 configuration effectively suppresses satellites and mists, allowing for high-frequency driving without increasing the main pulse width, thereby improving discharge stability and image quality.
Implementation Method 1
a driving signal, which includes a plurality of pulses in one discharge cycle for forming one dot, is supplied to an actuator for applying the pressure to the liquid contained in the pressure chamber. The plurality of pulses is composed of, for example, a main pulse, a pre-pulse which is applied before the main pulse, and a cancel pulse which is applied after the main pulse.
Implementation Method 2
The first portion has the smallest channel cross-sectional area of those of the plurality of portions. A relational expression of S1≤0.3×S0 and a relational expression of S1≤0.7×S2 are fulfilled, assuming that S0 represents channel cross-sectional area of the pressure chamber, S1 represents channel cross-sectional area of the first portion, and S2 represents channel cross-sectional area of the second portion.
Data Source
AI summary
A liquid discharge head is provided, which includes a nozzle plate which is formed with nozzles, and a channel member which is formed with pressure chambers and connecting channels for connecting the pressure chambers and the nozzles. The connecting channel includes a plurality of portions which have mutually different channel cross-sectional areas. The plurality of portions includes a first portion which is adjacent to the pressure chamber, and a second portion which is adjacent to the first portion, the first portion being interposed between the pressure chamber and the second portion. The first portion has the smallest channel cross-sectional area of those of the plurality of portions. S1≤0.3×S0 and S1≤0.7×S2 are fulfilled (S0: channel cross-sectional are of the pressure chamber, S1: channel cross-sectional area of the first portion, S2: channel cross-sectional area of the second portion).