Liquid Jet Head Retreat Dynamics for Floating Medium Avoidance

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Solution Overview

Problem

Existing liquid jetting apparatuses face challenges in efficiently managing the floating of media during printing, leading to increased power requirements and potential motor size increases when simultaneously moving multiple liquid jet heads, which can result in larger control units.

Innovation Solution

A liquid jetting apparatus with a medium transport unit, floating detection, and multiple liquid jet heads where the movement parameters of the second liquid jet head are set to be smaller than the first, allowing for staggered and reduced power consumption during retreat operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple liquid jet heads are simultaneously moved to retreat positions at the same speed and acceleration, then all jet heads can avoid the floating medium portion effectively, but the power required for the mechanism increases significantly

Engineering Contradiction:
Improvefloating avoidance effectivenessVSAvoidpower required for mechanism
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The patent applies dynamics by making the movement parameters (speed and acceleration) of the liquid jet heads variable rather than constant. Specifically, the downstream jet heads move with smaller speed and acceleration magnitudes compared to upstream jet heads during retreat operations. This dynamic adjustment reduces the power burden on the driving mechanism while still achieving effective avoidance of floating medium portions, as each jet head's movement is optimized according to its position and the urgency of avoidance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the movement parameters (speed and acceleration) of different liquid jet heads based on their position in the transport direction. Downstream jet heads are assigned smaller parameter magnitudes compared to upstream jet heads. This parameter differentiation allows the system to reduce overall power consumption during retreat operations while maintaining effective floating avoidance, as the parameter changes are tailored to the specific requirements of each jet head's position.

Inventive Principle:
Principle #35Parameter changes

2Loss of time

If multiple liquid jet heads are simultaneously moved to retreat positions with high speed and acceleration, then the response time to floating detection is reduced, but the motor size and control unit size must be increased

Engineering Contradiction:
Improveresponse time to floating detectionVSAvoidmotor size and control unit size
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent applies dynamics by implementing variable speed and acceleration profiles for different liquid jet heads during retreat operations. Downstream jet heads use smaller parameter magnitudes compared to upstream jet heads. This dynamic parameter adjustment enables the system to achieve effective floating avoidance with reduced motor power requirements, thereby avoiding the need for oversized motors and control units while still maintaining appropriate response times.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the movement parameters (speed and acceleration) based on the position of each liquid jet head in the transport direction. By assigning smaller parameter magnitudes to downstream jet heads, the system optimizes the balance between response time and hardware size. This parameter differentiation allows the use of smaller, more cost-effective motors and control units while maintaining effective floating avoidance capabilities.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3521033B1Liquid ejection apparatus and method for addressing floating of medium
Publication Date: 2022.09.28 FUJIFILM CORP
  • EP3521033B1 patent drawingFigure 1
  • EP3521033B1 patent drawingFigure 2
  • EP3521033B1 patent drawingFigure 3

AI summary

There are provided a liquid jetting apparatus and a method of coping with the floating of a medium where power at the time of coping with the floating of a medium can be suppressed. After the floating of a medium (36) is detected, a first movement parameter that represents the speed or acceleration of a first liquid jet head (56C) during movement is set, a second movement parameter that represents the magnitude of speed of a second liquid jet head (56M), which is smaller than the magnitude of the speed of the first liquid jet head, or a second movement parameter that represents a magnitude of acceleration of the second liquid jet head, which is smaller than the magnitude of the acceleration of the first liquid jet head, is set, an operation of the first liquid jet head is started at a first timing, and an operation of the second liquid jet head is started at the same timing as the first timing or at a second timing when the first liquid jet head does not yet reach a first retreat position.