Liquid Ejecting Head Parallel Detection Resistors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid ejecting heads face challenges in accurately detecting liquid temperature due to noise interference from drive currents, particularly because resistors used for temperature detection have high resistance values due to lengthy wiring, leading to reduced current flow and increased noise influence.
Innovation Solution
The liquid ejecting head incorporates a configuration where first and second detection resistors, formed from the same material as individual and common electrodes, are coupled in parallel to reduce combined resistance, thereby increasing current flow and minimizing noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the resistor is wired in the vicinity of the pressure chamber to detect temperature, then temperature detection capability is improved, but noise from drive current increases due to increased resistance from lengthy wiring
Solution Approach 1:
The patent combines the temperature detection resistor with the electrode structure by forming the resistor using the same material and process as the electrode, integrating two functions into one component. This eliminates separate wiring and reduces resistance while maintaining temperature detection capability near the pressure chamber.
Solution Approach 2:
The electrode structure serves dual functions: as both the drive electrode for piezoelectric actuation and as the temperature detection resistor. This multi-functional design eliminates the need for separate detection wiring, reducing resistance and noise susceptibility while enabling temperature measurement.
2Measurement precision
If the resistor is disposed in a meandering manner to fit the pressure chamber vicinity, then temperature detection coverage is improved, but resistance value increases due to increased wiring length
Solution Approach 1:
The patent merges the detection resistor with the electrode structure, eliminating separate meandering wiring. The resistor is formed directly as part of the electrode pattern, achieving compact layout and reduced resistance simultaneously while maintaining coverage of the pressure chamber area.
3Object-affected harmful factors
If larger current is fed to the resistor to reduce noise influence, then noise reduction is improved, but overvoltage state may occur
Solution Approach 1:
The patent changes the resistance parameter of the detection element by forming the resistor with the same material and structure as the electrode, resulting in lower resistance. This allows adequate detection current flow without requiring excessive current that would cause overvoltage, thereby reducing noise influence while avoiding overvoltage conditions.
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 configuration effectively reduces the influence of noise from drive currents on temperature detection, allowing for more accurate temperature measurement and improved operational reliability of the liquid ejecting head.
Implementation Method 1
piezoelectric bodies provided between the plurality of individual electrodes and the at least one common electrode, respectively, and driven in order to apply a pressure to a liquid inside the plurality of pressure chambers
Implementation Method 2
a first detection resistor formed from an identical material to a material of at least any of the plurality of individual electrodes and the at least one common electrode, and designed to change a resistance value depending on a temperature of the liquid inside the plurality of pressure chambers included in the first pressure chamber line
Data Source
AI summary
A liquid ejecting head includes a first detection resistor designed to change its resistance value depending on a temperature of the liquid inside the pressure chambers in the first pressure chamber line, a second detection resistor designed to change its resistance value depending on a temperature of the liquid inside the pressure chambers in the second pressure chamber line, a wiring board, a first coupling terminal that couples one end of the first detection resistor and one end of the second detection resistor in common to the wiring board, and a second coupling terminal that couples another end of the first detection resistor and another end of the second detection resistor in common to the wiring board.