Air Guide Structure for Carrier Plate Airflow Control
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Solution Overview
Problem
Inkjet printing systems using vacuum suction to hold print media often experience unintended blurring of images due to air currents induced by the vacuum suction, particularly at the edges of the print media, leading to inaccurate and blurry printed images.
Innovation Solution
An airflow control system is implemented, which includes air supply units that selectively flow air through the printing system based on the location of the print medium relative to the printhead, using an air guide structure with an angled end wall to direct airflow and reduce crossflows that cause blurring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vacuum suction is used to hold print media against the movable support surface, then the print media can be securely held in place without slippage during transport, but air currents are induced through uncovered holes that deflect ink droplets and cause image blurring
Solution Approach 1:
The patent extracts and removes the harmful air currents induced by vacuum suction through uncovered holes. By detecting when holes are uncovered and selectively disabling vacuum suction to those specific holes, the system removes the source of air currents that deflect ink droplets and cause image blurring, while maintaining vacuum suction to covered holes that securely hold the print media.
Solution Approach 2:
The patent introduces an intermediary detection and control system between the vacuum source and the holes in the movable support surface. Sensors detect whether holes are covered or uncovered, and a controller selectively activates or deactivates vacuum suction to individual holes based on their coverage status, mediating the vacuum application to eliminate harmful air currents while preserving media holding.
2Stability of the object's composition
If vacuum suction is applied continuously to all holes, then the print media remains securely held throughout transport, but ink droplets are deflected by induced air currents causing blur in printed images
Solution Approach 1:
The patent makes the vacuum suction system dynamic and adaptive rather than static and continuous. The system continuously monitors the coverage status of each hole and dynamically adjusts vacuum suction application in real-time. When holes become uncovered during media transport, vacuum suction to those holes is temporarily disabled to prevent air current induction, while vacuum suction to covered holes continues to maintain media stability.
Solution Approach 2:
The patent applies different vacuum suction conditions to different locations (holes) based on their local coverage status. Each hole is independently controlled - holes covered by media receive continuous vacuum suction to maintain positioning stability, while uncovered holes have vacuum suction disabled to prevent air current induction and image blur. This localized quality control resolves the contradiction between overall media stability and local print accuracy.
3Shape
If holes in the movable support surface are kept open for vacuum suction, then print media can be held flat during transport, but uncovered holes create air flow that causes blurring of printed images near edges
Solution Approach 1:
The patent extracts and eliminates the harmful air flow generated by uncovered holes. By detecting uncovered holes and selectively disabling vacuum suction to those specific holes, the system removes the source of air currents that cause image blurring at edges, while maintaining vacuum suction to covered holes that keep the print media held flat during transport.
Solution Approach 2:
The patent implements a feedback control system where sensors continuously monitor whether holes are covered or uncovered, and this information feeds back to the controller which adjusts vacuum suction application accordingly. This closed-loop feedback ensures that vacuum suction is maintained only where it serves the useful function of holding media flat, while being disabled where it creates harmful air currents that blur images.
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
The airflow control system effectively reduces or eliminates crossflows, ensuring that ink droplets are deposited accurately, resulting in clearer and more precise printed images without the blurring issues associated with vacuum suction.
Implementation Method 1
The vacuum source creates a vacuum state in the vacuum plenum, causing vacuum suction through holes in the movable support surface that are fluidically coupled to the vacuum plenum. When a print medium is introduced onto the movable support surface, the vacuum suction generates suction forces that hold the print medium against the movable support surface.
Implementation Method 2
The air flow control system comprises an air supply unit arranged to flow air through the opening of the carrier plate between the carrier plate and the printhead. The air supply unit comprises an air guide structure comprising: an air outlet portion extending into the opening of the carrier plate between the printhead and the carrier plate, the air outlet portion terminating in an end wall that is angled obliquely relative to the movable support surface towards a reverse-process direction.
Data Source
AI summary
A printing system comprises a print fluid deposition assembly, a media transport device, and an air flow control system. The print fluid deposition assembly comprises a printhead to eject a print fluid through an opening of a carrier plate to a deposition region. The media transport device holds a print medium against the movable support surface by vacuum suction and transports the print medium through the deposition region. The air flow control system comprises an air supply unit to selectively flow air through the opening based on a location of a print medium relative to the printhead. The air supply unit comprises an air guide structure comprising an air outlet portion extending into the opening of the carrier plate between the printhead and the carrier plate, the air outlet portion terminating in an end wall that is angled obliquely relative to the movable support surface towards a reverse-process direction.