Thermal Transfer Printer Band Ink Replenishment

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Solution Overview

Problem

Traditional thermal transfer printers face limitations in achieving high speed and high pack rates due to the need for complex motor control and ribbon management, leading to ribbon waste and increased costs, as well as downtime for ink replenishment.

Innovation Solution

A thermal transfer printing apparatus and method utilizing a band with a textured ink roller that re-melts and re-coats hot melt ink, allowing continuous high-speed printing with a single motor and minimizing consumable usage by replenishing ink within the printer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional spool-to-spool printers use motor control to precisely move the ribbon, then printing precision is maintained, but device complexity and ribbon waste increase due to frequent acceleration, deceleration, and direction changes

Engineering Contradiction:
Improveprinting precisionVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system pre-positions the printhead adjacent to the substrate before printing begins. The substrate is fed through the printing apparatus and positioned in advance, eliminating the need for complex ribbon shuttling and repositioning operations during printing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention extracts the substrate from the traditional ribbon-based system and makes it the primary moving component. Instead of moving the ribbon back and forth, the substrate moves continuously through the printer while the printhead remains stationary or moves minimally, simplifying the mechanical system.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If traditional printers use shuttle mechanisms to move the ribbon back and forth for each print, then ink can be applied to the substrate, but productivity is limited by the shuttle's travel distance and movement time

Engineering Contradiction:
Improvepack rateVSAvoidshuttle mechanism complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The substrate moves continuously through the printing apparatus without interruption. The feeding mechanism maintains constant substrate movement, and the printhead applies ink continuously or in rapid succession as the substrate passes by, eliminating the stop-start nature of traditional shuttle systems.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

Instead of moving the ink-carrying ribbon to the substrate, the invention inverts the approach by moving the substrate through the stationary printhead. This reversal eliminates the need for complex ribbon shuttling mechanisms and enables higher printing speeds.

Inventive Principle:
Principle #13The other way round (Inversion)

3Measurement precision

If traditional thermal transfer printers use ribbon form rolled onto spools with electric motor control, then precise ribbon movement is achieved, but loss of time occurs due to ribbon waste and frequent replenishment

Engineering Contradiction:
Improveribbon position controlVSAvoiddowntime for ink replenishment
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system incorporates an ink replenishment mechanism that automatically adds hot melt ink to the band during operation. The heating device and ink supply system work together to maintain ink availability on the band without requiring manual intervention or system shutdown.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the state of the ink from solid to liquid/melted form during the printing process. The heating device melts the hot melt ink on the band, allowing it to be replenished and redistributed. This phase change enables continuous ink supply without stopping the printer.

Inventive Principle:
Principle #35Parameter changes

4Loss of substance

If traditional printers accelerate and decelerate the ribbon between each print to prevent waste, then ribbon utilization is optimized, but speed is reduced due to repeated acceleration and deceleration cycles

Engineering Contradiction:
Improveribbon wasteVSAvoidprinting speed
Core Design Contradiction:
Loss of substanceVSSpeed

Solution Approach 1:

The substrate moves continuously through the printing apparatus without acceleration and deceleration cycles. The feeding mechanism maintains constant velocity, and the printhead is positioned ready to print at all times, enabling continuous high-speed operation without the speed losses inherent in traditional start-stop printing.

Inventive Principle:
Principle #20Continuity of useful action

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

Enables high-speed, high-pack-rate printing with reduced ribbon waste and lower operational costs, as well as reduced downtime and extended band durability, allowing for efficient and cost-effective coding on flexible films.

Implementation Method 1

operating the heating device to heat the band to cause ink on the band to re-melt, flow and replace at least some of the portion of the ink transferred to the substrate previously before arriving at the printhead again for a next print

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

supplying new ink to a second side of the solid heat conducting material of the ink roller, such that the new ink is retained by the textured outer surface

Methodology Applied
Scientific EffectSurface retention: Surface Tension

Implementation Method 3

actuating heaters in the thermal transfer printhead to transfer a portion of the ink from the band to the substrate to create a print on the substrate

Methodology Applied
Scientific EffectThermal transfer: Conduction (thermal)

Data Source

PatentEP3055135B1Apparatus and method for thermal transfer printing
Publication Date: 2019.07.10 DOVER EUROPE SARL
  • EP3055135B1 patent drawingFigure 1
  • EP3055135B1 patent drawingFigure 2A
  • EP3055135B1 patent drawingFigure 2B~2D

AI summary

Methods, systems, and apparatus, including medium-encoded computer program products, for thermal transfer printing include, in at least one aspect, a printing apparatus includes: a band capable of holding hot melt ink thereon; rollers configured and arranged to hold and transport the band with respect to a substrate; a printhead configured and arranged to thermally transfer a portion of the ink from the band to the substrate to print on the substrate; and a heating device configured and arranged to heat the band to cause ink on the band to re-melt, flow and replace at least some of the portion of the ink transferred to the substrate previously before arriving at the printhead again for a next print.