Integrated Fan Assembly for Cut Sheet Inkjet Printers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cut sheet inkjet printers face challenges in maintaining precise control over vacuum underpressure and air impingement flow, leading to difficulties in sheet retention and drying, especially with varying sheet sizes, which results in increased costs and space requirements due to separate subsystems for vacuum and hot air management.
Innovation Solution
A fan assembly that combines the functions of a suction box and an impingement unit using a single air fan, with adjustable valves to maintain constant underpressure and control air flow, allowing for precise control of both suction and air impingement, reducing the number of fans and space needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate subsystems are used for vacuum box and impingement unit, then functional reliability is improved, but device complexity and space requirements increase
Solution Approach 1:
The patent combines the vacuum box and impingement unit into a single integrated fan assembly where one fan serves both functions. The housing contains both the suction box for vacuum generation and the impingement unit for hot air drying, reducing the number of separate components while maintaining functional reliability through unified control.
Solution Approach 2:
The single fan in the integrated assembly performs multiple functions: it creates vacuum for sheet retention on the transport belt and simultaneously supplies air to the impingement unit for drying the printed sheets. This multi-functional design reduces device complexity and space requirements while maintaining the reliability of both vacuum and drying functions.
2Device complexity
If a single air fan is used for both suction box and impingement unit, then device complexity is reduced, but control precision becomes more difficult
Solution Approach 1:
The integrated fan assembly is divided into functionally independent sections: the suction box with its own valve for vacuum control and the impingement unit with its own valve for air flow control. This segmentation allows precise independent control of each function despite using a single fan, maintaining manufacturing precision while reducing device complexity.
Solution Approach 2:
The system employs controllable valves that dynamically adjust air flow distribution between the suction box and impingement unit based on operational requirements. This dynamic control mechanism enables precise regulation of vacuum levels and drying air flow independently, even though both functions share a common fan source.
3Reliability
If high underpressure is applied for large cut sheets, then sheet retention is improved, but transport belt friction and wear increase
Solution Approach 1:
The suction box features a perforated plate with distributed open areas that create localized vacuum zones across the transport belt surface. This local quality approach applies vacuum pressure only where sheets are present rather than uniformly across the entire belt, reducing unnecessary friction and wear on the transport belt while maintaining effective sheet retention.
Solution Approach 2:
The system dynamically adjusts the vacuum underpressure level based on sheet size and position. For large cut sheets, the valve modulates the vacuum level to provide adequate retention while minimizing excessive pressure that would cause belt friction and wear. This parameter optimization resolves the contradiction between retention reliability and belt durability.
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 enables precise and accurate control of vacuum underpressure and air impingement, improving belt movement control, reducing wear and friction, and optimizing inkjet printer performance while minimizing costs and space requirements.
Implementation Method 1
the suction box is configured to contain an underpressure on an inner side of the wall, so as to cause a cut sheet to adhere to a perforated cut sheet transport belt moveable along the wall
Implementation Method 2
hot air impingement is used, that is, air is heated and expelled (impingement) onto the freshly printed cut sheets of the medium for drying
Data Source
AI summary
An air fan assembly includes a suction box including a wall having an open area distributed across the wall. The suction box is configured to contain an underpressure on an inner side of the wall, so as to cause a cut sheet to adhere to a perforated transport belt. An impingement unit is configured to expel air supplied thereto towards the perforated transport belt. An air fan is arranged to create and maintain the underpressure in the suction box and to supply the air to be expelled by the impingement unit via an air outlet of the suction box. A first valve is arranged upstream of the air fan for conditionally admitting an additional air flow into the suction box. An inkjet printer and a method of operating the air fan assembly include the air fan assembly.