Liquid Discharge Head Flow Passage Design for Stagnation Prevention
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Solution Overview
Problem
Conventional liquid discharge heads can create regions where liquid stagnates inside pressurizing chambers, leading to clogging of discharge holes.
Innovation Solution
The liquid discharge head design includes a second individual flow passage with a wide section and a narrow section, connected to a partial flow passage, which helps to prevent liquid stagnation by ensuring liquid flows freely to the discharge hole, reducing pressure loss and preventing pigment settlement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid is circulated in conventional liquid discharge heads, then pigment stagnation is prevented, but liquid stagnation regions are still created inside pressurizing chambers causing discharge hole clogging
Solution Approach 1:
The flow passage is divided into multiple separate passages (first flow passage and second flow passage) with different configurations. The first flow passage has a first flow direction while the second flow passage has a second flow direction, creating segmented flow paths that prevent stagnation by ensuring continuous liquid circulation through each passage.
Solution Approach 2:
Different regions of the flow passage are given different properties - the first flow passage is configured for a first flow direction while the second flow passage is configured for a second flow direction. This local differentiation ensures that liquid flows continuously through each passage without creating stagnation regions, as each passage has optimized local flow characteristics.
2Ease of operation
If pressurizing chambers are used to discharge liquid, then liquid discharge control is achieved, but liquid stagnation occurs inside pressurizing chambers leading to clogging
Solution Approach 1:
The pressurizing chamber is divided into a first pressurizing chamber and a second pressurizing chamber, each connected to its own flow passage. This segmentation allows independent pressure control for each chamber while ensuring that liquid flows through both passages, preventing stagnation and maintaining discharge hole functionality.
Solution Approach 2:
Instead of allowing liquid to stagnate in the pressurizing chamber and then discharge it, the invention inverts the approach by configuring flow passages that actively guide liquid flow away from stagnation-prone regions. The first and second flow passages are arranged to create continuous circulation, effectively reversing the problematic stagnation pattern.
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 design effectively prevents liquid stagnation and clogging of discharge holes, ensuring continuous and efficient liquid flow, even when printing with multiple colors or materials.
Implementation Method 1
The second individual flow passage (14) includes a wide section (14a) and a narrow section (14b), and a connection section (14c) connecting the wide section (14a) and the narrow section (14b). The wide section (14a) is connected, on the side surface (10b2) of the partial flow passage (10b), to a region at a height of up to 0.5 times of a height from the pressurizing chamber under surface (10b1) to the partial flow passage (10b).
Data Source
Figure 1(a)~1(b)
Figure 2
Figure 3(a)~3(b)
AI summary
The present invention has an object to provide a liquid discharge head that prevents as much as possible liquid from being stagnated, and a recording device that uses the liquid discharge head. A liquid discharge head 2 according to the present invention includes a flow passage member 4 and a plurality of pressurizing sections 48. The flow passage member 4 includes a plurality of discharge holes 8, a plurality of pressurizing chambers 10 respectively connected to a plurality of the discharge holes 8, a plurality of first flow passages 12 respectively connected to a plurality of the pressurizing chambers 10, a second flow passage 20 connected in common to a plurality of the first flow passages 12, a plurality of third flow passages 14 respectively connected to a plurality of the pressurizing chambers, and a fourth flow passage 24 connected in common to a plurality of the third flow passages 14. A plurality of the pressurizing sections 48 respectively pressurizes liquid in a plurality of the pressurizing chambers 10. The third flow passage 14 has a wide section 14a connected to the pressurizing chamber 10 and a narrow section 14b connecting the wide section 14a and the fourth flow passage 24. The wide section 14a is disposed toward the discharge hole 8 of the pressurizing chamber 10.