Angular Velocity Sensor With Parallel-Plate and Comb-Tooth Electrodes

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Solution Overview

Problem

Existing gyro sensors face challenges in achieving a balance between large displacement amounts and high linearity of displacement with respect to applied signals, leading to instability and noise in angular velocity detection.

Innovation Solution

The gyro sensor incorporates a combination of parallel plate and comb tooth electrode pairs, with the parallel plate electrodes on the outermost circumference and comb tooth electrodes inside, allowing for large displacements with high linearity and controlled damping characteristics, enhancing stability and accuracy in angular velocity detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single electrode configuration is used, then the structure is simple, but the displacement linearity and detection stability are insufficient

Engineering Contradiction:
Improveangular velocity detection precisionVSAvoidelectrode configuration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The electrode system is segmented into multiple functional pairs: parallel plate electrode pairs for generating primary displacement, comb tooth electrode pairs for controlling damping, and detection electrode pairs for measuring angular velocity. Each segment performs a specific function, collectively achieving high-precision measurement while maintaining manageable structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The movable portion serves multiple functions simultaneously: it acts as one element of the parallel plate electrodes, one element of the comb tooth electrodes, and couples to the detection electrodes. This multi-functionality reduces the need for separate components, achieving high measurement precision without proportionally increasing device complexity.

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

2Length of moving object

If parallel plate electrodes are used, then large displacement amounts are achieved, but linearity of displacement is reduced

Engineering Contradiction:
Improvedisplacement amountVSAvoiddisplacement linearity
Core Design Contradiction:
Length of moving objectVSManufacturing precision

Solution Approach 1:

Different electrode configurations are applied in different spatial zones: parallel plate electrodes are positioned where large displacement is needed, while comb tooth electrodes are positioned where damping control is needed. This local differentiation allows the system to achieve both large displacement amounts and high linearity simultaneously.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically changes operational parameters by selectively activating different electrode pairs. The parallel plate electrodes provide large displacement when activated, while the comb tooth electrodes adjust damping characteristics to maintain linearity. The detection electrodes measure the actual displacement to compensate for any non-linearity through signal processing.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If comb tooth electrodes are used, then damping control is improved, but displacement amount is reduced

Engineering Contradiction:
Improvedamping controlVSAvoiddisplacement amount
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The system dynamically switches between different electrode configurations based on operational requirements. The comb tooth electrodes provide enhanced damping control when needed, while the parallel plate electrodes provide large displacement when needed. This dynamic adaptability allows the system to maintain both reliability through good damping control and sufficient displacement amount.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The comb tooth electrodes are pre-configured to provide damping control before the measurement process begins, establishing stable oscillation conditions. This preliminary damping control ensures that subsequent displacement measurements using the parallel plate electrodes remain linear and reliable, without requiring the comb tooth electrodes to be continuously active at full strength.

Inventive Principle:
Principle #10Preliminary action

4Measurement precision

If multiple annular portions are used, then detection accuracy is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidmanufacturing complexity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

Multiple annular portions are nested concentrically around the central axis, with each annular portion serving as a detection element. This nested arrangement improves detection accuracy by providing multiple measurement zones while utilizing the same vertical space, thereby not significantly increasing manufacturing complexity compared to a single annular structure.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 enables stable and accurate detection of angular velocity with reduced noise by providing large displacement amounts and high linearity, improving the overall performance of the gyro sensor.

Implementation Method 1

a first fixed electrode fixed to the base body and facing a part of the first annular portion; and a second fixed electrode fixed to the base body and facing the first movable portion electrode, the second fixed electrode being one of a first comb tooth electrode pair

Methodology Applied
Scientific EffectElectrostatic force: Electrostatics

Implementation Method 2

a movable portion supported by the first fixed portion, a first gap being provided between the base body and the movable portion

Methodology Applied
Scientific EffectMechanical vibration: Vibration

Data Source

PatentEP4239287B1Angular velocity sensor
Publication Date: 2025.10.29 KK TOSHIBA
  • EP4239287B1 patent drawingFigure 1
  • EP4239287B1 patent drawingFigure 2
  • EP4239287B1 patent drawingFigure 3

AI summary

According to one embodiment, a sensor includes a base body, a first fixed portion, a movable portion, and first and second fixed electrodes. The first fixed portion is fixed to the base body. The movable portion is supported by the first fixed portion. The movable portion includes annular portions and connecting portions. The annular portions are concentric with the first fixed portion as a center in a first plane. One of the connecting portions connects one of the annular portions and an other one of the annular portions. The annular portions include first to third annular portions. The second annular portion includes a first movable portion electrode. The first fixed electrode is fixed to the base body and faces a part of the first annular portion. The second fixed electrode is fixed to the base body and faces the first movable portion electrode.