Liquid Ejection Head Timing for Separate Ejection and Circulation Frequencies

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Solution Overview

Problem

Existing liquid ejection apparatuses face challenges in driving ejection and circulation driver elements at optimal frequencies due to the same drive frequency being used, leading to inefficiencies and increased circuit data transfer requirements.

Innovation Solution

The apparatus employs separate drive frequencies for ejection and circulation driver elements, allowing optimal operation by using different drive frequencies for each, thereby reducing data transfer and optimizing the timing for both processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the ejection driver element and circulation driver element are driven at the same drive frequency, then the circuit data transfer is simplified, but the circulation driver element cannot be driven at its optimal drive frequency

Engineering Contradiction:
Improvecircuit data transferVSAvoidcirculation driver element operation efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent divides the drive signal generation into separate segments: the ejection drive signal is generated based on ejection timing, while the circulation drive signal is generated based on circulation timing. This segmentation allows each driver element to operate at its optimal frequency independently, resolving the contradiction between circuit simplicity and operational efficiency.

Inventive Principle:
Principle #1Segmentation

2Productivity

If separate drive frequencies are used for ejection and circulation driver elements, then optimal operation for each is achieved, but circuit data transfer requirements increase

Engineering Contradiction:
Improvedriver element operation efficiencyVSAvoidcircuit data transfer
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic timing control where the circulation drive signal timing is adjusted relative to the ejection drive signal timing. The circulation timing is set to occur during periods when ejection is not active, creating a dynamic schedule that optimizes both operations without requiring overly complex data transfer protocols.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If the circulation driver element operates at non-optimal frequency, then circuit control is simplified, but ink circulation efficiency decreases

Engineering Contradiction:
Improvedrive frequency controlVSAvoidink circulation performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent employs periodic action by cycling the circulation driver element at its optimal frequency during intervals when ejection is not occurring. This periodic circulation ensures ink freshness and proper flow dynamics are maintained, while the overall control structure remains manageable through structured timing sequences.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4711138A1Liquid ejection head and liquid ejection apparatus
Publication Date: 2026.03.18 CANON KK
  • EP4711138A1 patent drawingFigure 1A~1B
  • EP4711138A1 patent drawingFigure 2A~2D
  • EP4711138A1 patent drawingFigure 3

AI summary

A liquid ejection head (1) includes: an ejection module (11) which includes an ejection driver element (MD1) and an ejection heater (RhA) capable of being electrically connected to the ejection driver element (MD1); a circulation module (12) which includes a circulation driver element (MD2) and a circulation heater (RhB) capable of being electrically connected to the circulation driver element (MD2); and a controller (202) which controls each of the ejection driver element (MD1) and the circulation driver element (MD2) into any one of a conduction state and a non-conduction state. The controller (202) makes an ejection drive frequency utilized to drive the ejection driver element (MD1) and a circulation drive frequency utilized to drive the circulation driver element (MD2) different from each other.