Magnetic Permeability Sensor Using Dual Oscillation Circuits
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Solution Overview
Problem
Existing toner sensors face challenges in accurately detecting magnetic permeability and dielectric permittivity due to complex configurations, size limitations, and variability in circuit components, leading to inaccurate measurements and increased complexity in detection processes.
Innovation Solution
A magnetic permeability sensor and dielectric permittivity sensor design featuring two oscillation circuits with coils or capacitors arranged at different distances from the subject material, utilizing a microcomputer for frequency measurement and calculation to convert frequency differences into permeability or permittivity values, allowing for accurate and compact detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a differential transformer method with four coils is employed to detect toner concentration, then the detection capability is improved, but the device complexity and size increase
Solution Approach 1:
The patent extracts only the essential functional elements needed for detection. Instead of using four coils in a differential transformer configuration, it employs a single oscillation circuit with one coil, removing redundant components while maintaining detection capability through frequency-based measurement
Solution Approach 2:
The patent replaces the mechanical/differential transformer method with an electrical oscillation-based system. By measuring frequency changes in an oscillation circuit rather than using mechanical differential transformations, the system achieves simpler configuration and smaller size while maintaining measurement precision
2Measurement precision
If coils are arranged horizontally at different distances from the subject material to suppress magnetic flux interference, then the measurement accuracy is improved, but the device size increases
Solution Approach 1:
The patent transitions from horizontal arrangement of coils to a vertical/distance-based arrangement. By positioning a single coil at a specific distance from the subject material and using oscillation frequency measurement, it achieves accurate magnetic permeability detection without requiring multiple horizontally spaced coils, thus reducing sensor size
3Measurement precision
If phase shift detection method with multiple oscillation circuits is used to detect metal state, then the detection capability is improved, but the detection process complexity increases
Solution Approach 1:
The patent extracts only the frequency measurement aspect of oscillation-based detection, eliminating the need for multiple oscillation circuits and phase shift calculations. By using a single oscillation circuit and measuring its frequency directly, it simplifies the detection process while maintaining measurement precision
Solution Approach 2:
The patent uses the oscillation frequency of a single circuit as a direct indicator of magnetic permeability changes, rather than creating complex phase shift relationships between multiple circuits. This single-frequency measurement approach copies the essential detection function in a simplified manner
4Volume of stationary object
If flat coils are used in oscillation circuits to achieve compact design, then the device size is reduced, but the inductance change magnitude decreases making analog operation difficult
Solution Approach 1:
The patent replaces analog operation methods with digital frequency measurement. By measuring the oscillation frequency of the circuit, which changes with inductance variations in the flat coil, it achieves accurate detection of small inductance changes without requiring large signal variations needed for analog operation
Solution Approach 2:
The patent changes the measurement parameter from voltage or current (analog) to frequency. Frequency measurement provides higher precision and is more sensitive to small inductance changes in flat coils, enabling accurate detection despite the small magnitude of inductance variation
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 solution enables precise and efficient detection of magnetic permeability and dielectric permittivity with a reduced sensor size and simplified configuration, minimizing the impact of component variations and environmental influences, while allowing for selective detection of either property.
Implementation Method 1
a first oscillation circuit performing oscillation in a state of including a first coil receiving magnetism from the subject material
Implementation Method 2
a first oscillation circuit performing oscillation in a state of including a first coil receiving magnetism from the subject material
Data Source
AI summary
Each of the oscillation frequency of a first oscillation circuit performing oscillation in a state of including a coil and a capacitor and the oscillation frequency of a second oscillation circuit performing oscillation in a state of including a coil and a capacitor different from the coil and the capacitor of the first oscillation circuit is measured. Then, the difference of the measured oscillation frequencies is calculated and then the calculated difference is converted into a magnetic permeability or a dielectric permittivity. One sensor selectively detects a change in the magnetic permeability or a change in the dielectric permittivity of a subject material.