Nozzle Characteristics via Thermal Sensing in Fluid Ejection

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Solution Overview

Problem

Existing fluid ejection devices lack effective methods to monitor and determine nozzle characteristics, such as operational status and blockage, which affects the performance and reliability of fluid drop ejection.

Innovation Solution

Implementing a control engine that monitors nozzle temperatures and temperature changes during ejection events to determine nozzle characteristics, including operational status and blockage, using temperature sensors and processing resources to analyze temperature data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If temperature sensors and control engine are added to monitor nozzle temperatures, then nozzle characteristic determination capability is improved, but device complexity increases

Engineering Contradiction:
Improvenozzle characteristic determinationVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The temperature sensor serves multiple functions: it monitors nozzle temperature for characteristic determination, tracks temperature changes over time, and provides data for detecting both operational status and blockage conditions. This multi-functionality improves measurement capability while minimizing the addition of separate dedicated components.

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

Solution Approach 2:

The system uses the existing temperature sensor data to self-diagnose nozzle characteristics without requiring external inspection equipment or manual testing. The control engine automatically analyzes temperature patterns to determine operational status, blockage conditions, and other nozzle characteristics, enabling the system to monitor itself.

Inventive Principle:
Principle #25Self-service

2Reliability

If temperature monitoring during ejection events is implemented, then operational status detection is improved, but use of energy increases

Engineering Contradiction:
Improveoperational status detectionVSAvoiduse of energy
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

Temperature monitoring is performed periodically during ejection events rather than continuously, with the control engine analyzing temperature data at specific intervals when nozzles are actively ejecting. This periodic measurement approach improves operational status detection while minimizing energy consumption compared to continuous monitoring.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system performs temperature monitoring and analysis during the ejection event itself, using the thermal data generated by the ejection process to determine nozzle characteristics. This approach leverages the existing thermal energy from the ejection event rather than requiring additional energy-intensive active heating or cooling for measurement purposes.

Inventive Principle:
Principle #10Preliminary action

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

Enables accurate determination of nozzle characteristics, improving the reliability and performance of fluid ejection by identifying non-operative or blocked nozzles and optimizing ejection processes.

Implementation Method 1

a fluid ejection die may comprise at least one temperature sensor for each set of nozzles. In some examples, a fluid ejection die may comprise at least one temperature sensor for each nozzle

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 2

For example, if fluid ejectors of the nozzles correspond to thermal fluid ejectors, a temperature of a fluid ejection die may increase responsive to actuation of the thermal fluid ejector

Methodology Applied
Scientific EffectThermal actuation:

Implementation Method 3

In addition, when fluid drops are ejected from the nozzle, a temperature decrease/cooling effect may occur

Methodology Applied
Scientific EffectCooling effect: Cooling

Data Source

PatentEP3551462B1Nozzle characteristics
Publication Date: 2025.10.29 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3551462B1 patent drawingFigure 1
  • EP3551462B1 patent drawingFigure 2
  • EP3551462B1 patent drawingFigure 3A~3B

AI summary

Examples include a fluid ejection device. The fluid ejection device comprises a fluid ejection die and a control engine. The fluid ejection die comprises nozzles to eject fluid drops and a temperature sensors disposed on the die to sense temperatures associated with nozzles. The control engine determines at least one nozzle characteristic of at least one respective nozzle based at least in part on a temperature change associated with the at least one respective nozzle corresponding to at least one ejection event.