Dielectric Heating Control Using Electrode Impedance Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dielectric heating devices require a water content sensor to be positioned in contact with or facing the recording medium, which can be impractical and limit the flexibility of the heating process.
Innovation Solution
A dielectric heating device that includes an electrode unit, a voltage application unit, a current value detection unit, a phase difference detection unit, an impedance detection unit, and a control unit. This configuration allows for the detection of impedance based on current value and phase difference, enabling the control unit to adjust the output of alternating-current power to the electrode unit without the need for a water content sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a water content sensor is provided at a position to contact or face the recording medium, then the water content can be measured, but the device complexity increases and the positioning becomes impractical
Solution Approach 1:
The patent extracts the measurement function from a separate water content sensor and integrates it into the existing electrode unit. By detecting impedance changes of the electrode unit itself, the system eliminates the need for additional sensors while maintaining measurement capability. This resolves the contradiction by removing the complex sensor positioning requirement while preserving water content detection.
Solution Approach 2:
The electrode unit is given a dual function: it serves both as the heating element for dielectric heating and as the sensing element for water content detection through impedance measurement. This multi-functionality eliminates the need for separate measurement devices, reducing device complexity while maintaining measurement precision.
2Measurement precision
If a water content sensor is provided at a position to contact or face the recording medium, then the water content can be measured, but the ease of operation decreases
Solution Approach 1:
The patent removes the requirement for separate sensor positioning by extracting the measurement function into the electrode unit. The impedance detection automatically occurs through the existing electrode configuration, eliminating operational complexity related to sensor placement while maintaining accurate water content measurement.
3Reliability
If feedback control is performed based on water content sensor measurement, then the heating amount can be adjusted, but the device complexity increases due to additional sensor requirements
Solution Approach 1:
The electrode unit performs dual functions as both heater and sensor. The impedance detection unit monitors water content through the electrode unit's electrical properties, and the control unit adjusts heating power based on this feedback. This integrated approach maintains reliable heating control while reducing overall device complexity by eliminating separate measurement sensors.
Solution Approach 2:
The system implements feedback control by continuously monitoring impedance changes in the electrode unit and adjusting the heating power accordingly. The impedance detection unit provides real-time water content information to the control unit, which modulates the voltage application to maintain optimal heating conditions without requiring additional sensor hardware.
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 device can effectively adjust the heating amount of the recording medium based on its dryness degree without the need for a sensor, enhancing flexibility and efficiency in the heating process.
Implementation Method 1
an electrode unit (20) including a first electrode (31) and a second electrode (32) that face a to-be-heated object (OH), and configured to heat the to-be-heated object (OH)
Implementation Method 2
an impedance detection unit (512) configured to detect an impedance (Zr) of the electrode unit (20) based on the current value and the phase difference
Data Source
AI summary
A dielectric heating device includes: an electrode unit including a first electrode and a second electrode that face a to-be-heated object, and configured to heat the to-be-heated object; a voltage application unit configured to apply an alternating-current voltage to the first electrode and the second electrode; a current value detection unit configured to detect a current value of an alternating current that flows through the electrode unit; a phase difference detection unit configured to detect a phase difference between the alternating-current voltage and the alternating current; an impedance detection unit configured to detect an impedance of the electrode unit based on the current value and the phase difference; and a control unit configured to control output of alternating-current power output to the electrode unit by controlling the voltage application unit based on the impedance.