Printing Apparatus Tension Control for Base Material

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Solution Overview

Problem

Existing printing apparatuses face challenges in maintaining consistent tension during the transport of elongated strip-shaped base materials, leading to variations in tension that affect print quality, particularly for materials susceptible to expansion and contraction.

Innovation Solution

A printing apparatus and method that include a tension controller, which adjusts the brake torque of rollers based on the type, thickness, width, and winding diameter of the base material, using acquisition and judgment parts to ensure the tension remains within a target value, employing normal and acceleration-varied control strategies to minimize tension variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the tension applied to the base material is controlled during transport, then the target tension value can be approached, but large variations in tension occur causing expansion/contraction phenomenon and lowering print quality

Engineering Contradiction:
Improvetension control accuracyVSAvoidprint quality consistency
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by detecting tension variations before they cause significant expansion or contraction of the base material. The tension sensor continuously monitors tension during transport, and the controller adjusts brake torque proactively to prevent large tension variations from occurring, rather than correcting them after the damage is done.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback control by using a tension sensor to continuously detect the actual tension applied to the base material during transport. The controller compares the detected tension with the target tension value and adjusts the brake torque accordingly to maintain tension within the appropriate range, ensuring consistent print quality.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If the brake torque is adjusted to maintain target tension, then tension control improves, but tension variations still occur during transport of expansion-prone materials

Engineering Contradiction:
Improvetension control accuracyVSAvoidbase material dimensional stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent applies dynamics by making the brake torque adjustable and responsive during the transport process. Rather than using a fixed brake torque, the controller dynamically adjusts the brake torque based on real-time tension detection, allowing the system to adapt to changing conditions and material properties during transport.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the brake torque parameter in response to detected tension variations. The controller changes the brake torque parameter dynamically during transport to maintain tension within the target range, preventing expansion or contraction of the base material.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If constant tension is applied to all material types, then the system is simple to operate, but materials with different expansion properties cannot be properly handled

Engineering Contradiction:
Improvesystem operation simplicityVSAvoidmaterial type adaptability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the target tension value adjustable based on material type. Different target tension values can be set for different materials (e.g., paper, film, vinyl), allowing the system to adapt to the specific expansion properties of each material while maintaining ease of operation through a user-friendly interface.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by allowing the target tension parameter to be changed according to the material being printed. The system can store multiple target tension values corresponding to different material types, and the appropriate value is selected based on the material being processed.

Inventive Principle:
Principle #35Parameter changes

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 suppresses tension variations, thereby improving print quality by ensuring consistent tension application during the transport of base materials, even those prone to expansion and contraction.

Implementation Method 1

a brake 11A that applies brake torque to the rotary shaft of the unwinding roller 11

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3456543B1Printing apparatus and printing method
Publication Date: 2021.04.21 SCREEN HOLDINGS CO LTD
  • EP3456543B1 patent drawingFigure 1
  • EP3456543B1 patent drawingFigure 2
  • EP3456543B1 patent drawingFigure 3

AI summary

A printing apparatus (1) includes a controller (40) for applying tension to a base material (9) to be printed thereon while applying brake torque to an unwinding roller (11) around which the base material (9) is wound, and a tension sensor (14) for detecting the tension applied to the base material (9). The controller (40) acquires information related to the base material (9). The controller (40) exercises first control for rotating the unwinding roller (11) with a constant acceleration, if the acquired information is included in a first condition. The controller (40) exercises control for rotating the unwinding roller (11) with an acceleration slower than the constant acceleration and/or with an S-shaped acceleration, if the acquired information is not included in the first condition.