Inkjet Recording Head Temperature Feedback for Circulation Fault Detection

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Solution Overview

Problem

Ink viscosity increases around the ejection port of a recording head due to evaporation of volatile components, leading to clogging and ejection failures, and existing methods to prevent this, such as stopping ink circulation, fail to maintain ink concentration and temperature control effectively.

Innovation Solution

A recording device with a control system that determines the normalcy of ink circulation by monitoring temperature changes in the recording head, using temperature detection elements and a control unit to adjust and maintain optimal circulation conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If ink circulation is stopped after recording ends, then evaporation of volatile components around the ejection port is prevented, but ink concentration in the circulation path increases

Engineering Contradiction:
Improveevaporation of volatile componentsVSAvoidink concentration
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The system continuously monitors temperature changes in the recording head and adjusts circulation pump operation accordingly. Temperature detection elements provide feedback to the control unit, which determines circulation normalcy and adjusts pump driving to maintain optimal ink conditions without excessive concentration buildup

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The circulation pump operation is dynamically adjusted based on real-time temperature monitoring. The system transitions between different circulation states (normal, abnormal, stopped) based on temperature change patterns, allowing adaptive response to actual ink conditions rather than fixed operation modes

Inventive Principle:
Principle #15Dynamics

2Reliability

If the recording head temperature is maintained at high temperature for heating elements, then ink ejection performance is improved, but temperature drops slowly after heating stops due to stored heat

Engineering Contradiction:
Improveink ejection performanceVSAvoidrecording head temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

Temperature detection elements continuously monitor the recording head temperature and provide feedback to the control unit. Based on this feedback, the system determines whether temperature changes indicate normal or abnormal circulation, enabling precise control of the heating and circulation system

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system replaces simple thermal management with an intelligent control system that uses temperature sensors and control algorithms to manage heat. The control unit analyzes temperature change patterns to distinguish between normal post-heating cooling and abnormal circulation conditions

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If the circulation pump is operated continuously, then ink circulation is maintained, but abnormal circulation due to clogging or bubbles cannot be detected

Engineering Contradiction:
Improveink circulation maintenanceVSAvoidcirculation normalcy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The control unit receives continuous temperature feedback from detection elements and analyzes temperature change patterns to determine circulation normalcy. This feedback mechanism enables detection of abnormal conditions such as clogging or bubbles that disrupt normal temperature dynamics

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Temperature acts as an intermediary parameter that reflects the actual circulation state. By monitoring temperature changes rather than directly measuring flow, the system indirectly detects circulation abnormalities caused by clogging or bubbles

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Prevents ink viscosity increase and ejection failures by ensuring normal ink circulation, allowing for reliable recording operations.

Implementation Method 1

a temperature detection element to detect a temperature change in the recording head

Methodology Applied
Scientific EffectTemperature detection: Thermistor

Implementation Method 2

the recording head may include a heater to increase the temperature of the recording head and maintain the temperature at a high temperature state

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

the recording head may include a heating element to foam the ink by thermal energy

Methodology Applied
Scientific EffectThermal energy: Joule Heating

Implementation Method 4

the viscosity of ink around an ejection port of a recording head increases due to the evaporation of volatile components in the ink from the ejection port

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP4600043A1Recording device
Publication Date: 2025.08.13 CANON KK
  • EP4600043A1 patent drawingFigure 1
  • EP4600043A1 patent drawingFigure 2
  • EP4600043A1 patent drawingFigure 3

AI summary

A recording device including a recording head, a circulation unit and a control unit is used. The recording head includes an ejection port and a pressure chamber filled with ink, and performs recording operation by ejecting ink from the ejection port. The circulation unit performs circulation operation to circulate ink through a circulation path including the pressure chamber. The control unit acquires temperature information, which is information on temperature of the recording head, in a state where the circulation unit is performing the circulation operation, and determines a circulation state of the ink in the circulation path based on the information on the temperature.