Liquid Ejection Head Dual Pump Pressure Control
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Solution Overview
Problem
Existing liquid ejection systems face challenges in quickly stopping ink circulation during cap sucking and wiping operations, leading to prolonged downtime and decreased productivity due to the difficulty in eliminating differential pressure between supply and collection pressures.
Innovation Solution
Incorporating a second pump that operates in reverse to the first pump, allowing for active elimination of differential pressure between the first and second pressure control chambers, thereby facilitating quicker cessation of ink flow and reducing downtime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single pump is used to circulate ink with differential pressure control, then the system structure is simple, but the ink circulation cannot be stopped quickly during cap sucking and wiping operations
Solution Approach 1:
The single pump system is segmented into two independent pump units (first pump and second pump) that can operate independently. This allows the first pump to be stopped while the second pump actively eliminates differential pressure, enabling quick cessation of ink circulation during cap sucking and wiping operations without requiring complete system shutdown.
Solution Approach 2:
Instead of simply stopping the circulation pump and waiting for natural pressure equalization, the invention uses the second pump to actively create reverse flow that rapidly eliminates the differential pressure. This inverted approach transforms a passive waiting process into an active controlled process, reducing downtime significantly.
2Reliability
If the circulation pump is stopped to perform cap sucking and wiping operations, then color mixing is prevented, but productivity decreases due to prolonged downtime
Solution Approach 1:
The second pump is activated in advance to rapidly eliminate differential pressure before cap sucking and wiping operations begin. This preliminary action ensures that ink circulation is completely stopped before the operations start, preventing color mixing while minimizing the total downtime by overlapping the pressure elimination process with the preparation for maintenance operations.
Solution Approach 2:
While the first pump is stopped for maintenance operations, the second pump continues to operate to maintain pressure equilibrium and prevent any residual circulation. This continuous useful action ensures that the system remains in a controlled state throughout the maintenance period, preventing color mixing while minimizing operational interruption.
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 enables rapid elimination of differential pressure, preventing color mixing and reducing downtime, thus enhancing productivity by allowing for quicker recovery operations.
Implementation Method 1
a first pump unit which is provided between the second pressure control unit and the first pressure control unit and which is capable of sending the liquid from the second pressure control unit to the first pressure control unit
Implementation Method 2
a liquid sending unit which is provided outside a first channel for a flow from the supply channel to the collection channel via the ejection unit, and which is capable of sending the liquid from the first pressure control unit to the second pressure control unit while bypassing the ejection unit
Data Source
AI summary
Provided are a liquid ejection head and a liquid ejection apparatus capable of reducing a decrease in productivity. To this end, a liquid sending unit is provided which is provided outside a first channel for a flow from a supply channel to a collection channel via pressure chambers and which is capable of sending a liquid from a first pressure control chamber to a second pressure control chamber.