Ink Supply Air Removal via Preliminary Ejection Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ink jet printers face issues with ink ejecting failure due to air in the supply tube, leading to waste ink when the suction pump applies negative pressure, causing the ink level to reach its limit and potentially leaving air in the tube.
Innovation Solution
A liquid droplet ejecting apparatus with a main tank, sub-tank, ejecting head, suction pump, and controller that controls the suction pump and ejecting pressure device to discharge air from the sub-tank while managing the ink level, ensuring air is removed from the supply passage without reaching the ejecting head, using a gas permeable film to block liquid flow and simplify control processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the suction pump applies negative pressure to discharge air from the sub-tank, then air removal is improved, but the ink level rises to the upper limit and may cause ink to be suctioned together with air
Solution Approach 1:
The ejecting pressure applying device is activated before the suction pump to pre-lower the ink level in the sub-tank. This preliminary action creates space for air discharge while preventing ink from being suctioned along with air, as the ink level is already reduced below the suction inlet position.
Solution Approach 2:
The ejecting pressure applying device applies positive pressure to counteract the negative pressure from the suction pump before air discharge begins. This preliminary anti-action prevents ink from being drawn into the suction path by creating a pressure barrier that pushes ink away from the suction inlet.
2Reliability
If the alarm induces ink change before the main tank is empty, then air suction is prevented, but waste ink occurs
Solution Approach 1:
The air layer is extracted from the ink supply tube through the suction pump, separating it from the ink. This allows the ink to be fully consumed in the main tank without air contamination, eliminating the need for premature ink replacement and reducing waste ink.
Solution Approach 2:
The sub-tank serves as an intermediary chamber between the main tank and ejecting head. Air is discharged in the sub-tank before ink flows from the main tank, preventing air from reaching the ejecting head while allowing complete ink utilization from the main tank.
3Reliability
If the ink level in the sub-tank is high when air discharge begins, then the ink level reaches upper limit immediately, but air may remain in the supply tube
Solution Approach 1:
The ejecting pressure applying device is activated before the suction pump to pre-lower the ink level in the sub-tank. This preliminary action creates space for air discharge while preventing ink from being suctioned along with air, as the ink level is already reduced below the suction inlet position.
Solution Approach 2:
The controller monitors the ink level in the sub-tank and adjusts the operation of the ejecting pressure applying device and suction pump accordingly. When the ink level approaches the upper limit, the controller activates the ejecting device to lower the level, ensuring continuous effective air discharge without ink contamination.
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
Effectively discharges air from the supply tube, reduces waste ink, and efficiently lowers the ink level in the sub-tank, ensuring reliable operation by controlling the ejecting pressure and suction processes.
Implementation Method 1
a suction pump that applies a negative pressure to an air layer inside of the sub-tank to discharge air from inside the sub-tank to outside
Implementation Method 2
an ejecting pressure applying device that applies a feed pressure to the liquid inside the passage toward the nozzle to eject the liquid from the nozzle
Data Source
AI summary
A liquid droplet ejecting apparatus comprises an ejecting head including a passage which is connected to a sub-tank and an ejecting pressure applying device which applies a feed pressure to the liquid inside the passage, a main tank detector which detects that a main tank is mounted to a main tank mounting portion, a suction pump which applies a negative pressure to an air layer inside the sub-tank to discharge air from inside the sub-tank to outside, and a controller configured to control the suction pump and the ejecting pressure applying device, based on information from the main tank detector. The controller causes the suction pump to discharge the air from inside the sub-tank to outside and causes the ejecting pressure applying device to eject the liquid from a nozzle, when the main tank detector detects that the main tank is mounted to the main tank mounting portion.