Inkjet Purging Mechanism with Deformable Sub Tank
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid droplet ejecting apparatuses face challenges in efficiently restoring ink ejection performance due to clogging caused by viscous ink and air bubbles, often requiring complex structures and high costs, with previous solutions either wasting ink or requiring manual operation.
Innovation Solution
A liquid droplet ejecting apparatus with a purging mechanism that pressurizes a liquid in a temporary storing chamber to pressure-feed it towards the nozzle, using a second pressure-feed portion with a pressure chamber and a flow resistance generator in the liquid communication passage to efficiently discharge clogged materials without increasing components or costs, and allowing for manual operation if needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cap is used to cover the nozzles and suck fresh ink to eliminate bubbles and foreign material, then the purging operation can be performed, but a large volume of ink is wasted corresponding to the inner volume of the cap
Solution Approach 1:
The patent extracts the harmful elements (bubbles and foreign material) from the ink system by forcing fresh ink through the nozzles under pressure, eliminating the need for a cap to receive discharged ink. The harmful substances are removed directly into the receiving pan without requiring the cap's inner volume, thus reducing ink waste while maintaining purging effectiveness
Solution Approach 2:
Instead of sucking ink out through negative pressure as in conventional methods, the patent applies positive pressure to force ink through the nozzles in the opposite direction. This inversion of the pressure application method allows ink to be pushed through the clogged nozzles rather than pulled, reducing the amount of ink lost in the process
2Loss of substance
If positive pressure is applied to ink in the sub tank to pressure-feed it into the recording head, then ink waste is reduced compared to suction method, but the structure becomes more complex requiring additional pressure application mechanisms
Solution Approach 1:
The patent makes the sub tank serve multiple functions: it acts as both the storage container for ink and the pressure application mechanism. By making the sub tank itself deformable, it can be compressed to apply positive pressure to the ink without requiring separate pumps or pressure generators, thus reducing device complexity while maintaining the ink waste reduction benefit
Solution Approach 2:
The sub tank is designed to be self-sufficient by incorporating deformability directly into its structure. The tank can autonomously apply pressure to its own contents through external compression, eliminating the need for auxiliary pressure application devices and simplifying the overall system structure
3Device complexity
If the sub tank is made deformable to apply pressure to ink, then the structure is simplified, but control over pressure application becomes less precise
Solution Approach 1:
The patent incorporates a compression amount detection means that monitors how much the sub tank is compressed. This feedback mechanism allows the control system to adjust the compression force to achieve the desired pressure level, compensating for the reduced precision inherent in deformable tank pressure application and maintaining ease of operation
4Reliability
If fresh ink is forcibly pressure-fed into the recording head from the upstream side, then bubbles and foreign material can be eliminated, but the amount of ink discharged is large
Solution Approach 1:
The patent applies partial action by compressing the sub tank only to the extent necessary to force ink through the nozzles, rather than continuously applying high pressure. The compression is sufficient to eliminate bubbles and foreign material but controlled to minimize excessive ink discharge, achieving the balance between purging effectiveness and ink conservation
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 solution effectively reduces ink waste and simplifies the structure while maintaining reliable purging operations, enhancing the efficiency and reliability of ink discharge without the need for complex devices or manual manipulation.
Implementation Method 1
a second pressure-feed portion which has an inner volume larger than that of the first pressure-feed portion, and is disposed between the tank and the first pressure-feed portion, pressure-feeds the liquid supplied from the tank to the nozzle via the first pressure-feed portion to eject the liquid from the nozzle in an amount larger than an amount of the liquid ejected by the first pressure-feed portion as the liquid droplet
Implementation Method 2
a liquid communication passage which holds the tank and the nozzle in communication with each other via the pressure chamber, and which includes a flow resistance generator which is disposed in at least one of a portion of the liquid communication passage between the tank and the pressure chamber, and a portion of the liquid communication passage between the pressure chamber and the nozzle, the flow resistance generator giving a flow resistance to the liquid as flowing in the at least one of the two portions of the liquid communication passage
Data Source
AI summary
There is disclosed a liquid droplet ejecting apparatus including: a tank storing a liquid; a nozzle from which the liquid is ejected in the form of a droplet; a first pressure-feed portion which is disposed between the tank and the nozzle, and pressure-feeds the liquid as supplied from the tank, to eject the liquid droplet from the nozzle; a second pressure-feed portion which has an inner volume larger than that of the first pressure-feed portion, and is disposed between the tank and the first pressure-feed portion, the second pressure-feed portion pressure-feeding the liquid as supplied from the tank to the nozzle via the first pressure-feed portion, to eject the liquid from the nozzle in an amount larger than an amount of the liquid ejected by the first pressure-feed portion as the liquid droplet; and the second pressure-feed portion including: a pressure chamber; a pressurizing member that pressurizes the liquid in the pressure chamber by decreasing an inner volume of the pressure chamber; and a liquid communication passage which holds the tank and the nozzle in communication with each other via the pressure chamber, and which includes a flow resistance generator which is disposed in at least one of a portion of the liquid communication passage between the tank and the pressure chamber, and a portion of the liquid communication passage between the pressure chamber and the nozzle, the flow resistance generator giving a flow resistance to the liquid as flowing in the at least one of the two portions of the liquid communication passage.