Inkjet Printer Suction Pump Periodic Action for Bubble Drainage
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Solution Overview
Problem
Existing liquid ejection apparatuses, such as inkjet printers, face challenges in effectively draining bubbles from filters during choke cleaning, leading to reduced ink supply performance and degraded printing quality, especially with complex recording heads or easily foaming inks.
Innovation Solution
A control method for a liquid ejection apparatus that alternates between suction and suspension with the valve mechanism closed, accumulating negative pressure to efficiently remove bubbles from the filter through the nozzle, improving bubble drainage performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pump is maintained in the stopped state from time TA to time TB to allow bubbles to join together, then bubble coalescence is promoted, but bubbles are caught by the filter and drainage performance deteriorates
Solution Approach 1:
The patent applies periodic action by alternately operating the pump between suction mode and stopped state during the cleaning process. The pump is operated to generate negative pressure, then stopped to allow bubbles to coalesce, and this cycle is repeated multiple times. This periodic operation enables bubbles to accumulate and grow to a size that allows them to pass through the filter during the suction phases, thereby improving drainage performance while maintaining effective bubble removal.
2Stress or pressure
If choke cleaning is performed with the valve closed and pump stopped to join bubbles, then negative pressure accumulation is achieved, but bubbles are trapped on the filter and ink supply performance decreases
Solution Approach 1:
The patent employs periodic action by cycling the pump between suction operation and stopped state. During suction phases, negative pressure is generated to draw ink and detached bubbles through the nozzles. During stopped phases, negative pressure is maintained to allow remaining bubbles to coalesce and detach from the filter. This periodic cycling ensures both sufficient negative pressure accumulation and continuous ink supply, resolving the contradiction between pressure maintenance and productivity.
Solution Approach 2:
The patent applies preliminary action by performing multiple cycles of suction and suspension before the final drainage phase. During these preliminary cycles, bubbles are gradually detached from the filter and accumulated in the ink passage. By the time the valve is opened for final drainage, a sufficient quantity of coalesced bubbles is already prepared and ready to be expelled, ensuring effective bubble removal without compromising ink supply performance.
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 method enhances bubble drainage efficiency by promoting the joining of bubbles on the filter, allowing for effective removal of impurities and maintaining ink flow quality, thereby improving printing performance.
Implementation Method 1
suction of the liquid from the passage through the nozzle
Implementation Method 2
accumulating a negative pressure in the passage at a side downstream from the valve mechanism
Implementation Method 3
A filter is arranged between the valve mechanism and the liquid ejection head
Implementation Method 4
the valve mechanism is opened so that, using the negative pressure accumulated in the passage, bubbles are removed from the filter through the nozzle together with the liquid
Data Source
AI summary
A printer includes a recording head having a nozzle that ejects ink and a suction pump that draws the ink through the nozzle. A valve unit and a filter are arranged in a passage that supplies the ink to the recording head. A controller of the printer operates the suction pump to perform suction/suspension in which suction of the ink from the passage through the nozzle and suspension of the suction are alternately repeated with the valve unit maintained in a closed state, thus promoting joining of bubbles on the filter. The controller then operates to open the valve unit to drain the joint bubbles from the filter, together with the ink, using negative pressure accumulated in the passage.