Inkjet Substrate Gap Reduction for Turbulence-Free Printing
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Solution Overview
Problem
Inkjet printers face issues with printing errors due to air turbulence and substrate movement at gaps between discrete substrates, leading to defects like blurring and collisions, which existing solutions like vacuum adjustment and valve systems fail to fully address.
Innovation Solution
The method involves detecting and reducing or eliminating the gap between consecutive substrates by adjusting their relative speed, using acceleration and deceleration to ensure consistent printing speed and substrate alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If vacuum suction is used to hold substrates in place, then substrate positioning is improved, but air turbulence occurs at gaps between substrates causing printing errors
Solution Approach 1:
The patent extracts the harmful air flow from the system by introducing a cover element that blocks the suction openings at the gaps between substrates. This allows the vacuum suction to continue holding substrates in place while preventing air turbulence from occurring at the gaps, thereby eliminating the harmful effect while preserving the beneficial substrate positioning.
Solution Approach 2:
The cover element acts as an intermediary component between the suction system and the substrate gaps. It mediates the conflict by allowing vacuum pressure to be applied to substrates for positioning while simultaneously blocking the air flow path that would create turbulence, thus resolving the contradiction between positioning accuracy and turbulence prevention.
2Manufacturing precision
If adjustable walls are used to match suction width to substrate width, then air flows at substrate sides are prevented, but gaps between discrete substrates create turbulence
Solution Approach 1:
The patent removes the harmful air flow path at substrate gaps by using a cover element to block the suction openings in gap regions. This extraction of the harmful air flow allows the adjustable walls to maintain their function of preventing side air flows while the cover element specifically addresses the gap turbulence problem.
Solution Approach 2:
The cover element is designed with selective blocking characteristics - it blocks suction openings only in the gap regions between substrates while leaving the suction openings under the substrates open. This local differentiation allows the system to prevent turbulence at gaps while maintaining vacuum holding of substrates, addressing the specific local problem without affecting overall substrate control.
3Measurement precision
If inkjet printing is performed at high speed with small ink drops, then printing resolution is improved, but air flows from substrate gaps divert ink drops causing printing errors
Solution Approach 1:
The patent extracts the harmful air flow that interferes with ink drop trajectory by blocking the suction openings at substrate gaps with a cover element. This eliminates the air turbulence that would otherwise divert ink drops, allowing high-speed printing with small ink drops to achieve both high resolution and accurate placement.
Solution Approach 2:
The cover element is positioned upstream of the printing area to preemptively block the air flow path before ink drops are ejected. By preventing the formation of turbulent air flows at the gaps before the printing process, the system ensures that ink drops follow their intended trajectory without being diverted, thus maintaining printing precision at high speeds.
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 approach minimizes air turbulence and printing errors by maintaining substrate alignment, ensuring precise ink drop placement and preventing collisions, thus enhancing printing quality and efficiency.
Implementation Method 1
The conveyor device passes the substrates to be printed below the print heads (injectors) for them to be printed with inks of different colours... the conveyor system to comprise a perforated belt which, in conjunction with an air suction system, generates a vacuum which holds the substrates in place
Implementation Method 2
One problem associated with the suction mechanism is that it can give rise to air flows and/or turbulence around the edges of the substrate to be printed
Implementation Method 3
Said turbulence and/or flows can interfere with the path of the ink drops, leading to printing errors in said edge areas
Data Source
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AI summary
Method for printing substrates by injection of ink, which comprises the following steps: - placing a first substrate and a second discrete substrate in a device for conveying substrates, said substrates being arranged immediately consecutively in the conveyor device, there being a distance between the first and the second substrate in the direction of travel of the conveyor device, - supplying, consecutively, by means of said conveyor device, said first substrate and second substrate to a printing area, - consecutively printing said first substrate and said second substrate, said substrates being in movement during printing, which comprises the following step: - reducing said distance between the first substrate and the second substrate, prior to supplying said second substrate to the printing area, such that the distance between the first substrate and the second substrate during the printing step is less than the distance between the first substrate and the second substrate when they were placed in the conveyor device.