Movable Baffle Airflow Control for Inkjet Printing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet printing systems using vacuum suction for media transport often experience image blurring due to air currents induced by the suction, particularly at the edges of the print media, leading to inaccurate droplet placement and potential jams.
Innovation Solution
An airflow control system with movable baffles that selectively block airflow through upstream and downstream sides of printhead openings, synchronized with the position of the inter-media zone, to reduce or eliminate crossflows that cause blurring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vacuum suction is used to hold and transport print media, then the print media can be securely held in place without slippage, but air currents are induced that cause unintended blurring of images
Solution Approach 1:
The vacuum plenum is divided into multiple separate plenums (first vacuum plenum and second vacuum plenum) that are independently controllable. This segmentation allows selective application of vacuum suction to different zones, enabling the system to maintain media holding stability in some areas while minimizing air currents in others, thus resolving the contradiction between reliable media holding and precise image placement.
2Reliability
If vacuum suction force is increased to prevent media slippage, then media transport reliability improves, but air currents intensify causing more severe image blurring
Solution Approach 1:
Different vacuum suction forces are applied to different spatial zones using the segmented vacuum plenums. The system can apply stronger vacuum suction where media holding is critical while applying weaker suction or no suction in zones where air currents would interfere with droplet placement, thereby achieving both high reliability and high precision simultaneously through localized quality control.
3Reliability
If uncovered holes are present in the media transport device for vacuum suction, then vacuum suction can be applied to hold media, but air flows through these holes causing blurring of printed images
Solution Approach 1:
The harmful airflow effect is extracted and isolated by directing it into a dedicated vacuum plenum that is separated from the droplet deposition zone. The vacuum holes that would otherwise allow harmful air currents to flow through the media path are instead channeled into the vacuum plenum system, removing the harmful effect while preserving the useful vacuum suction function for media holding.
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 solution effectively reduces image blurring by ensuring that ink droplets land closer to their intended locations, maintaining printing accuracy and speed while preventing jams, and allows for increased vacuum suction force without blurring issues.
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
Implementation Method 2
The airflow control system blocks airflow through an upstream side of the printhead opening while allowing airflow through a downstream side of the printhead opening
Data Source
AI summary
A printing system comprises an ink deposition assembly, a media transport device, and an airflow control system. The ink deposition assembly comprises a printhead to eject ink through a carrier plate opening in a carrier plate. The media transport device holds a print medium against a movable support surface by vacuum suction and transports the print media through a deposition region. The airflow control system comprises a baffle that is movable between an upstream-blocking configuration and a downstream-blocking configuration, and an actuator configured to move the baffle. In the upstream-blocking configuration the baffle blocks airflow through an upstream side of the printhead opening while allowing airflow through a downstream side of the printhead opening. In the downstream-blocking configuration the baffle blocks airflow through the downstream side of the printhead opening while allowing airflow through the upstream side of the printhead opening.