Ink Supply Device Backflow Prevention Float Seal
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Solution Overview
Problem
Inkjet printers face issues with ink backflow due to excessive supply in the ink chamber, which is difficult to control when accurate ink level detection is impossible, leading to unwanted ink suction by the pressure control means.
Innovation Solution
An ink supply device with a sub tank and main tank system, featuring a pressure control means and a backflow prevention section using a float member that seals the pressure control hole opening as the ink level rises, preventing ink from reaching the pressure control means and thus preventing backflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pressure control means is provided to control the inner pressure of the ink chamber, then the ink supply is improved and ink ejection is stabilized, but ink may be excessively supplied to the ink chamber causing backflow when level detection fails
Solution Approach 1:
The float member is positioned to seal the pressure control hole opening before ink can reach it through excessive supply. This preliminary protective action prevents the harmful effect of ink backflow into the pressure control means, allowing the pressure control system to continue functioning reliably without being contaminated by ink.
2Stress or pressure
If the pressure control means sucks air to reduce inner pressure of the ink chamber, then negative pressure is achieved to prevent ink dripping, but the same means may suck ink when the ink level is excessively high
Solution Approach 1:
The float member acts as an intermediary protective barrier between the ink and the pressure control means. When ink level rises excessively, the float member rises and seals the pressure control hole opening, preventing ink from reaching and being sucked by the pressure control means, thus protecting the intermediary system from contamination.
3Device complexity
If no backflow prevention structure is provided, then the device complexity is reduced, but ink level control accuracy deteriorates when excessive supply occurs
Solution Approach 1:
The float member utilizes the natural buoyancy force and the existing ink level changes to automatically seal the pressure control hole opening when ink becomes excessively supplied. This self-activating mechanism provides backflow prevention without requiring external power sources, complex control systems, or additional actuators, thereby maintaining simplicity while improving reliability.
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 prevents ink backflow by sealing the pressure control hole opening with a float member, ensuring accurate ink supply and reducing the risk of ink suction, even when the ink level exceeds the predetermined limit.
Implementation Method 1
a backflow prevention section (132) comprising a float member (133) which floats on liquid ink and a supporting member (132a) which supports the float member (133) such that the float member (133) freely moves vertically in response to changes of the ink level in the ink chamber
Data Source
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AI summary
It is an object to provide an ink supply device for an inkjet printer which is capable of preventing ink from being sucked by a pressure control means, i.e. preventing the backflow of the ink even when the ink is excessively supplied in an ink chamber. An ink supply device comprises a sub tank (120), which is connected to a print head (60) and which is provided therein with an ink storage chamber (123), a main tank which is connected to the sub tank (120), a sub tank depressurizing unit and a sub tank pressurizing unit which are connected to an air introduction hole (129a) formed in the sub tank (120) to control the inner pressure of the ink storage chamber (123). In the ink storage chamber (123), a backflow prevention section (132) comprising a sealing float (133 and a float supporting members (132a) is formed. The float supporting members (132a) support the sealing float (133) such that the sealing float (133) can move vertically in response to changes of the ink level. When the sealing float (133) moves upwardly according to the rise of the ink level, the sealing float (133) seals the ink storage chamber-side opening of the air introduction hole (129a).