Vibrating Arm Frequency Tuning to Prevent Vibration Leakage

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Solution Overview

Problem

Existing vibration elements, such as those used in vibratory gyroscopes, face issues with vibration balance deviation over time due to unintended mass changes on non-irradiated surfaces during laser-based mass adjustment, leading to vibration leakage.

Innovation Solution

A frequency adjustment method that differentiates the activation amount between the front and back surfaces of the vibrating arms by using energy rays, where the activation amount on the second principal surface is smaller than on the first principal surface, to minimize unintended mass changes and maintain vibration balance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the weight layer is irradiated with a laser to adjust mass, then the resonance frequency can be adjusted, but foreign matters adhere to the activated surface causing vibration balance to deviate over time

Engineering Contradiction:

Improveresonance frequency adjustment precisionVSAvoidvibration balance stability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent converts the harmful effect of laser activation (which causes foreign matter adhesion) into a beneficial selective process. By controlling the laser irradiation parameters and timing, the activation is limited only to the weight layer material that needs to be removed, while the substrate surface remains unactivated and resistant to foreign matter adhesion. This resolves the contradiction by making the activation process selective rather than universal.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent applies different properties to different parts of the vibrating arm. The weight layer portion is activated by laser for mass adjustment, while the substrate portion maintains its original unactivated state. This local differentiation ensures that only the necessary area undergoes activation, preventing foreign matter adhesion on the substrate surface and maintaining long-term vibration balance.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If mass adjustment is performed on one principal surface, then resonance frequency is adjusted, but unintended mass change occurs on the other principal surface causing vibration balance deviation

Engineering Contradiction:

Improvemass adjustment precisionVSAvoidvibration balance consistency

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent converts the unintended side effect of backside activation into a controlled selective process. By optimizing laser parameters (power, pulse duration, wavelength), the activation is confined to the weight layer on the front surface, which has different optical absorption characteristics. The backside substrate remains unactivated, preventing unintended mass changes and maintaining vibration balance consistency.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Adaptability or versatility

If laser irradiation is used for mass adjustment, then frequency tuning is achieved, but activation causes foreign matter adhesion leading to vibration leakage

Engineering Contradiction:

Improvefrequency adjustment capabilityVSAvoidvibration leakage

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent creates a local quality difference between activated and unactivated surfaces. The weight layer is selectively activated for mass removal, while the substrate surface remains unactivated and maintains its original properties including resistance to foreign matter adhesion. This local differentiation eliminates the source of vibration leakage while preserving frequency adjustment capability.

Inventive Principle:

Principle #3Local quality

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 approach effectively reduces vibration leakage by controlling the bonding of substances on the surfaces, ensuring consistent resonance frequencies and maintaining the vibration balance of the drive arms over time.

Implementation Method 1

adjusting a resonance frequency of the vibration element by irradiating the vibration element, which includes a base and a vibrating arm having a first principal surface and a second principal surface that are in a front and back relationship with each other and extending from the base, with an energy ray

Methodology Applied

Scientific EffectLaser irradiation: Laser

Data Source

PatentUS11085765B2Frequency adjustment method of vibration element, manufacturing method of vibration element, vibration element, physical quantity sensor, inertial measurement device, electronic apparatus, vehicle

Publication Date: 2021.08.10 SEIKO EPSON CORP

AI summary

A frequency adjustment method of a vibration element includes adjusting a resonance frequency of the vibration element by irradiating the vibration element, which includes a vibrating arm having a first principal surface and a second principal surface that are in a front and back relationship with each other with an energy ray, to remove a part of the vibrating arm on the first principal surface, and in which an activation amount by the energy ray on the second principal surface of the vibrating arm is smaller than an activation amount by the energy ray on the first principal surface of the vibrating arm.