Variable Resonant Capacitance for Stable Cartridge Memory Power

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Solution Overview

Problem

Existing non-contact communication mediums in magnetic tape cartridges face instability in securing target electric power due to deviations in resonant capacitance values, leading to reduced current and power fluctuations.

Innovation Solution

A non-contact communication medium with a power generation unit, power monitoring unit, and capacitance control unit, which includes a resonant circuit, rectification circuit, current adjustment element, operational amplifier, and comparator, adjusts the resonant capacitance to maximize output voltage and stabilize power generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the memory size of the cartridge memory is increased to accommodate larger recording data sizes, then the storage capacity is improved, but the power consumption increases and the ability to securely obtain target electric power from the antenna deteriorates

Engineering Contradiction:
Improvememory sizeVSAvoidpower consumption
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the resonant capacitance variable rather than fixed. The capacitance value is dynamically adjusted based on the detected output voltage of the rectification circuit. When the output voltage is insufficient, the resonant capacitance is increased to improve power generation efficiency, enabling the system to adapt to varying power demands as memory size increases.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of resonant capacitance to optimize power generation. By varying the capacitance value in response to detected voltage levels, the system adjusts its electrical parameters to maximize power extraction from the antenna, thereby supporting higher power consumption associated with larger memory sizes.

Inventive Principle:
Principle #35Parameter changes

2Power

If the resonant capacitance value is adjusted to maximize output voltage, then the electric power generation is improved, but the current value decreases drastically when the capacitance deviates from the expected value, leading to unstable power supply

Engineering Contradiction:
Improveelectric power generationVSAvoidpower supply stability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent implements feedback by detecting the output voltage of the rectification circuit and using this information to adjust the resonant capacitance. This closed-loop control ensures that the capacitance is optimized based on actual operating conditions, maintaining stable power supply even when the optimal capacitance value differs from expectations due to manufacturing variations or environmental factors.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment by automatically modifying its own resonant capacitance based on detected voltage levels. This self-service mechanism enables the cartridge memory to optimize its power generation without external intervention, ensuring reliable operation across different conditions.

Inventive Principle:
Principle #25Self-service

3Device complexity

If a fixed resonant capacitance is used in the resonant circuit, then the device complexity is reduced, but the ability to securely obtain target electric power deteriorates when the capacitance value deviates from the expected value

Engineering Contradiction:
Improvecircuit complexityVSAvoidelectric power extraction
Core Design Contradiction:
Device complexityVSPower

Solution Approach 1:

The patent transitions from a static capacitance design to a dynamic one. By introducing a variable capacitance element that can be adjusted based on detected voltage levels, the system gains the ability to optimize power extraction without requiring complex external control mechanisms. The added complexity is minimal and justified by the significant improvement in power security.

Inventive Principle:
Principle #15Dynamics

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 ensures stable and maximized electric power delivery, minimizing power fluctuations and maintaining communication stability regardless of memory size increases.

Implementation Method 1

The power generation unit generates electric power supplied to the memory unit, the resonant circuit including an antenna coil and resonant capacitance

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a resonant circuit and a rectification circuit, and generates electric power to be supplied to the memory unit, the resonant circuit including an antenna coil and resonant capacitance unit

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3779794B1Non-contact communication medium, driving method thereof, and recording medium cartridge
Publication Date: 2023.09.06 SONY SEMICON SOLUTIONS CORP
  • EP3779794B1 patent drawingFigure 1
  • EP3779794B1 patent drawingFigure 2
  • EP3779794B1 patent drawingFigure 3~4

AI summary

A non-contact communication medium according to an embodiment of the present technology includes: a memory unit; a power generation unit; a power monitoring unit; and a capacitance control unit. The memory unit stores predetermined management information. The power generation unit includes a resonant circuit and a rectification circuit, and generates electric power to be supplied to the memory unit, the resonant circuit including an antenna coil and resonant capacitance unit having a variable capacitance value, the rectification circuit rectifying a resonant output of the resonant circuit. The power monitoring unit includes a current adjustment element, a reference voltage generation source, and an operational amplifier, the current adjustment element being connected in parallel to the rectification circuit with respect to the resonant circuit and having a variable resistance value, the reference voltage generation source generating a reference voltage, the operational amplifier controlling the current adjustment element such that an output voltage of the rectification circuit is equal to the reference voltage. The capacitance control unit is configured to control the resonant capacitance unit on the basis of an output of the operational amplifier.