Liquid Ejection Head Ink Circulation Without External Pumps
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid ejection devices require pumps and pressure adjusting mechanisms for ink circulation, leading to increased device size and complexity, and existing drive data management for ejection and flow energy generating elements is inefficient.
Innovation Solution
A liquid ejection head design that incorporates individual ejection units with both ejection and flow energy generating elements, where the flow energy generating element is driven independently to circulate ink, reducing the need for external pumps and optimizing drive data management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a differential-pressure circulation method is used to circulate ink, then ink circulation is achieved, but device size and complexity increase due to required pumps and pressure adjusting mechanisms
Solution Approach 1:
The patent extracts and eliminates the pump and pressure adjusting mechanism from the system by implementing a pure energy-generating-element-based circulation method. The flow energy generating element directly generates the energy needed for ink circulation without requiring external pumping devices or complex pressure control mechanisms, thereby simplifying the overall device structure while maintaining reliable ink circulation.
Solution Approach 2:
The patent replaces the mechanical pump and pressure adjusting mechanism with an energy generating element that converts electrical energy directly into mechanical energy for ink circulation. This substitution eliminates the need for complex mechanical coupling components and reduces device complexity while achieving the same ink circulation function.
2Reliability
If a pump is provided inside the liquid ejection head to circulate liquid, then ink circulation is achieved, but device size increases
Solution Approach 1:
The patent removes the pump from the head structure entirely, replacing it with a compact energy generating element that fits within the existing head architecture. This extraction of the bulky pump component directly reduces the head volume while maintaining effective ink circulation through the energy generating element's direct drive mechanism.
Solution Approach 2:
The patent substitutes the large mechanical pump with a compact energy generating element that converts electrical energy directly into the mechanical motion needed for ink circulation. This substitution dramatically reduces the space required for circulation mechanism within the head, thereby reducing overall head size.
3Productivity
If multiple energy generating elements are driven independently, then ejection and circulation functions are optimized, but drive data management becomes more complex
Solution Approach 1:
The patent segments the control of energy generating elements by separating ejection-related elements from circulation-related elements. This segmentation allows for independent optimization of each function while enabling more manageable drive data structure, as each segment can be controlled according to its specific operational requirements without interfering with the other.
Solution Approach 2:
The patent implements dynamic control where the drive signals for energy generating elements are adjusted based on real-time operational conditions. The controller dynamically determines which elements to drive and at what frequency, optimizing ejection efficiency while managing drive data complexity through adaptive rather than static control strategies.
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
This design reduces device size, minimizes waste ink, improves throughput, and maintains ejection stability by effectively circulating ink, even with varying ink types and concentrations, while reducing the amount of drive data required.
Implementation Method 1
a first energy generating element provided in the pressure chamber, and generating energy for ejecting the liquid from the ejection port
Implementation Method 2
a second energy generating element provided in the individual flow path
Data Source
AI summary
A liquid ejection head includes an individual ejection unit including an ejection port, a pressure chamber, a first energy generating element that ejects liquid from the ejection port, an individual flow path communicating with the pressure chamber, and a second energy generating element provided in the individual flow path; and a common flow path for supplying the liquid to the individual flow path of the individual ejection unit. When the first energy generating element is driven, the second energy generating element is not driven. When the first energy generating element is not driven, the second energy generating element is driven only when receiving a drive instruction signal for the second energy generating element.