Droplet Ejection Circuitry for Media Speed Adaptation

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Solution Overview

Problem

Current droplet deposition heads face challenges in efficiently adapting to varying deposition media speeds and maintaining consistent droplet patterns across diverse applications, such as inkjet printing and 3D printing, due to limitations in synchronized ejection timing and nozzle control.

Innovation Solution

A droplet ejection apparatus with actuating circuitry and head controller circuitry that generates and applies drive waveforms to nozzles to eject droplets with a constant frequency, adjusting ejection timing based on deposition media speed data to maintain consistent droplet spacing and pattern integrity across varying speeds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If droplet ejection timing is synchronized for all nozzle rows, then ejection coordination is simplified, but adaptability to varying media speeds deteriorates

Engineering Contradiction:
Improveejection control complexityVSAvoidadaptability to media speed variations
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent divides the ejection control into separate segments: a first latch section for storing initial ejection data and a second latch section for storing adjusted ejection data. This segmentation allows different timing adjustments for different nozzle rows while maintaining overall system coordination, resolving the contradiction between control simplicity and speed adaptability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic timing adjustment by allowing the second latch section to store ejection data with modified timing parameters based on detected media speed variations. This dynamic adjustment mechanism enables the system to adapt to varying media speeds while maintaining coordinated ejection across all nozzle rows.

Inventive Principle:
Principle #15Dynamics

2Productivity

If ejection frequency is increased to improve productivity, then output rate increases, but droplet placement precision deteriorates

Engineering Contradiction:
Improvedroplet ejection rateVSAvoiddroplet placement accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent employs feedback mechanisms where the system detects actual media speed during operation and adjusts ejection timing accordingly. This feedback loop allows the system to maintain precise droplet placement even at higher ejection frequencies by dynamically compensating for speed variations through the latch sections and timing adjustment circuitry.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3687800B1Method, apparatus and circuitry for droplet ejection
Publication Date: 2023.02.01 XAAR TECH LTD
  • EP3687800B1 patent drawingFigure 1
  • EP3687800B1 patent drawingFigure 2A
  • EP3687800B1 patent drawingFigure 2B

AI summary

A droplet ejection apparatus comprising: a droplet deposition head comprising an array of actuating elements and a corresponding array of nozzles; actuating circuitry, configured to apply drive waveforms to said actuating elements, thereby causing the ejection of fluid in the form of droplets through said array of nozzles onto deposition media,which are moved relative to the head; and head controller circuitry, configured to: receive an input set of ejection data; generate a series of sub-sets of ejection data based on the input set; and send said series of sub-sets of ejection data to said actuating circuitry; wherein the actuating circuitry is further configured so as to, for each sub-set of ejection data, apply drive waveforms to said actuating elements such that they repeatedly eject droplets from one or more nozzles, thus depositing successive rows of droplets, the one or more nozzles and the sizes of the droplets ejected therefrom being determined by the current sub-set of ejection data, each of the one or more nozzles ejecting droplets with a substantially constant frequency of 1/T; wherein the apparatus is configured to receive deposition media speed data, which indicates the current speed of relative movement of the head with respect to the deposition media; and wherein the apparatus is configured such that the head switches from ejecting droplets in accordance with a current sub-set of ejection data to ejecting droplets in accordance with a consecutive sub-set of ejection data in the series at a time determined in accordance with said media speed data, with the time interval between starting ejecting droplets in accordance with successive sub-sets of ejection data varying inversely with the current speed of relative movement of the head.