Liquid Ejecting Head Reverse Flow Purge
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Solution Overview
Problem
The accumulation of precipitable ingredients in the liquid flow passage and pressure chambers of a liquid ejecting apparatus leads to reduced flow rates during conventional purge operations, making it inefficient for eliminating these deposits, especially in regions where normal ink ejection is less frequent.
Innovation Solution
A liquid ejecting apparatus with a pressurization system that directs liquid flows from the liquid filling chambers through the nozzles and an outlet passage, where the flow rate from the liquid flow passage to the outlet passage is higher than the total flow rate from the nozzles, effectively dispersing and eliminating precipitable ingredients by creating counter-directed flows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional pressurized purge or suction purge is performed, then the liquid flow rate and flow speed in the ejecting head are increased, but the flows of liquid are produced in the same direction as normal ink ejecting operation, so that accumulation of precipitable ingredients in regions where flows are less prone to be produced is less prone to be eliminated
Solution Approach 1:
The patent introduces a drain passage that enables liquid to flow in the opposite direction (toward the outlet passage) compared to normal ejection (toward nozzles). This reverse flow direction allows liquid to冲刷 regions that are not effectively cleaned by conventional forward-direction purges, thereby eliminating accumulation of precipitable ingredients in previously inaccessible areas.
Solution Approach 2:
The liquid flow path is segmented into multiple directions: forward flow toward nozzles during normal operation, and reverse flow toward the outlet passage during purge operation. This segmentation allows different flow paths to address different cleaning needs, with the reverse flow specifically targeting regions where precipitable ingredients accumulate.
2Productivity
If conventional purge operation is performed with higher flow rate, then the liquid is forced through the nozzles, but the flow passages are not thoroughly cleaned in regions where flows are less prone to be produced
Solution Approach 1:
The drain passage creates a reverse flow path that enables liquid to move from the liquid flow passage toward the outlet passage, opposite to the normal ejection direction. This inverted flow direction ensures that regions not effectively cleaned by forward-flow purges are thoroughly flushed, maintaining high purge efficiency while achieving comprehensive cleaning coverage.
Solution Approach 2:
The liquid flow passage serves multiple functions: it supplies liquid to nozzles during normal operation and serves as a flow path for reverse-direction flushing during purge operation. This multi-functionality allows a single structure to address both normal ejection and comprehensive cleaning needs, improving overall system effectiveness.
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 efficiently disperses and eliminates precipitable ingredients in the liquid flow passage and filling chambers, ensuring effective maintenance of the ejecting head by enhancing the flow rate and ensuring thorough cleaning during the purge operation.
Implementation Method 1
a pressurizing part for pressurizing the interior of the liquid reservoir... when the pressurization is performed, the liquid stored in the liquid reservoir is supplied through the supply passage to the liquid flow passage
Implementation Method 2
Ink in the pressure chambers is jetted out of the nozzles by the deformation of piezoelectric elements provided in the respective pressure chambers
Data Source
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AI summary
This liquid ejecting apparatus includes an ejecting head (20), a liquid reservoir, a pressurizing part for the liquid reservoir, a supply passage, and an outlet passage. The ejecting head (20) includes a liquid flow passage (22), liquid filling chambers (23, 24) in communication with the liquid flow passage (22), and a plurality of nozzles (44) provided for the respective liquid filling chambers (24). When the pressurizing part performs pressurization, with the communication through the outlet passage ensured, a liquid in the liquid reservoir flows through the supply passage and is supplied through a supply port (221) to the liquid flow passage (22). Part of the liquid supplied to the liquid flow passage (22) is drained through an outlet port (222). This produces flows of liquid different from those produced during the ejection of the liquid from the nozzles (44) and directed from the supply port (221) toward the outlet port (222). Thus, precipitable ingredients accumulated in the liquid flow passage (22) are efficiently dispersed. That is, the accumulation of the precipitable ingredients in the ejecting head (20) is efficiently eliminated in the liquid ejecting apparatus capable of controlling the ejection of the liquid from the nozzles (44).