Liquid Ejection Head Pulse Control for Smaller Drive Circuits

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Solution Overview

Problem

Existing liquid ejection heads using both ejection and flow energy generating elements face circuit size challenges due to complex driving pulse and timing requirements, leading to increased circuit complexity.

Innovation Solution

A liquid ejection head design that incorporates both ejection and flow energy generating elements with optimized circuit configuration, reducing circuit size by employing a straight type flow passage arrangement and synchronized driving pulses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate driving circuits are provided for ejection energy generating elements and flow energy generating elements with time-division control, then driving precision is improved, but circuit size increases

Engineering Contradiction:
Improvedriving precisionVSAvoidcircuit size
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent combines the driving circuits for ejection energy generating elements and flow energy generating elements into a single integrated circuit. The control unit selectively applies driving pulses to different energy generating elements based on their operational requirements, merging previously separate circuits while maintaining precise control through selective activation rather than physical separation

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The driving circuit is designed with multi-functionality to handle both ejection operations and flow circulation operations. The control unit can selectively drive either ejection energy generating elements or flow energy generating elements using the same circuit infrastructure, making the circuit universal for multiple functions without requiring dedicated separate circuits for each function type

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If multiple energy generating elements are driven with different driving pulses and timing, then ejection performance is improved, but device complexity increases

Engineering Contradiction:
Improveejection performanceVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The control unit dynamically adjusts driving parameters including pulse width, amplitude, and timing based on real-time operational requirements. The system can flexibly modify driving conditions for different energy generating elements without fixed predetermined settings, enabling adaptive optimization of ejection performance while managing complexity through software-based dynamic control rather than hardwired complex circuitry

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs parameter changes in driving pulses (such as pulse width modulation and amplitude adjustment) to optimize the performance of different energy generating elements. By varying electrical parameters rather than creating physically different circuits, the system achieves differentiated control for ejection and flow elements while maintaining circuit simplicity

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 design achieves a reduction in circuit size while maintaining stable ink ejection and preventing ink concentration at the ejection ports, enhancing ejection stability and throughput.

Implementation Method 1

a first electrothermal conversion element that generates energy for ejecting the liquid

Methodology Applied
Scientific EffectElectrothermal conversion: Joule Heating

Implementation Method 2

generates energy for ejecting the liquid by forming a bubble in the liquid

Methodology Applied
Scientific EffectBubble formation: Bubble

Implementation Method 3

a flow energy generating element disposed in the flow passage... generates a circulation flow of the liquid in the flow passage

Methodology Applied
Scientific EffectFlow generation: Convection

Data Source

PatentEP4703139A1Liquid ejection head
Publication Date: 2026.03.04 CANON KK
  • EP4703139A1 patent drawingFigure 1A~1B
  • EP4703139A1 patent drawingFigure 2A~2D
  • EP4703139A1 patent drawingFigure 3A~3D

AI summary

A liquid ejection head (1) includes a first individual ejection unit, a second individual ejection unit, and a common flow passage (38) for supplying liquid. The first individual ejection unit and the second individual ejection unit each include an ejection port (11), a pressure chamber (12), a first energy generating element (14) that is provided in the pressure chamber, an individual flow passage (23) that communicates with the pressure chamber (12), and a second energy generating element (24) that is provided in the individual flow passage (23). The liquid ejection head (1) is characterized in that the first and second energy generating elements in each ejection unit are controlled differently for each individual ejection unit at a common driving timing, by a common driving pulse.