Liquid Ejecting Head Recess Depth Variation
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Solution Overview
Problem
Ink jet type recording heads face challenges in optimizing the size and discharge characteristics due to the size of the flow path forming substrate and the depth of the recess portion, which affects flow path resistance and discharge efficiency.
Innovation Solution
A liquid ejecting head design featuring a flow path forming substrate with individual flow paths and a communication plate with recess portions, where the supply path is opened on the bottom surface of the first recess portion and a second recess portion is deeper, acting as a throttle to improve discharge efficiency and reduce pressure loss, while preventing an increase in the size of the flow path forming substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the supply path is provided on the flow path forming substrate, then the discharge characteristics can be controlled, but the size of the flow path forming substrate becomes large
Solution Approach 1:
The patent divides the flow path system into two separate components: the flow path forming substrate and the communication plate. The supply path is relocated to the communication plate rather than being integrated into the flow path forming substrate. This segmentation allows the flow path forming substrate to maintain a compact size while the communication plate provides the necessary supply path functionality for controlling discharge characteristics.
Solution Approach 2:
The supply path is moved from the planar dimension of the flow path forming substrate to the vertical dimension by implementing it on the communication plate that overlays the flow path forming substrate. This dimensional transition allows the supply path to be formed in the thickness direction of the communication plate, enabling compact overall design while maintaining adequate supply path length and discharge control capability.
2Volume of stationary object
If the recess portion is formed to be deep, then the manifold volume increases, but the flow path length of the supply path becomes insufficient
Solution Approach 1:
The communication plate is designed with a recess portion that has non-uniform depth, creating different local qualities within the same structure. The recess portion has a first depth in the region corresponding to the supply path inlet and a second depth (greater than the first depth) in the region corresponding to the manifold. This local depth variation allows the supply path to achieve adequate length while the manifold region maintains sufficient volume for proper liquid distribution.
3Area of stationary object
If the supply path is provided in the communication plate, then the size is reduced, but when the flow path length is appropriately set, the depth of the recess portion decreases, increasing flow path resistance
Solution Approach 1:
The recess portion of the communication plate is designed with spatially varying depth characteristics. In the region where the supply path is formed, the recess portion has a first depth that allows adequate supply path length while maintaining low flow path resistance. In the manifold region, the recess portion extends to a second depth (greater than the first depth) to ensure sufficient manifold volume. This local quality differentiation resolves the contradiction between compact size and flow path resistance.
4Manufacturing precision
If the supply path and communication path are positioned on different substrates, then the discharge characteristics can be optimized, but position shifts cause uneven discharge
Solution Approach 1:
The supply path and communication path are both formed on the same communication plate substrate, merging their locations into a single component. This integration eliminates the position shift issues that would arise from aligning separate substrates, ensuring uniform discharge characteristics. The communication plate serves dual functions of providing both the supply path for liquid introduction and the communication path for liquid ejection to the nozzles.
Data Source
AI summary
A flow path forming substrate in which an individual flow path which communicates with a nozzle opening that discharges liquid is formed; and a communication plate in which a recess portion which configures at least a part of a common flow path that is common to and communicates with the plurality of individual flow paths is provided to be open on a side opposite to the flow path forming substrate, are provided, the recess portion includes a first recess portion, and a second recess portion which is deeper than the first recess portion, the communication plate includes a supply path which is provided to be open on a bottom surface of the first recess portion, communicates with the recess portion and the individual flow path, and becomes a throttle portion that throttles a flow path with respect to the individual flow path, and a communication path which communicates with the individual flow path and the nozzle opening, and in the individual flow path, a throttle portion which throttles the individual flow path from a part that communicates with the supply path to a part that communicates with the communication path, is not provided.