Piezoelectric Actuator Input Device Vibration Control

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Solution Overview

Problem

Existing input devices, such as touchpads, lack the ability to provide multiple types of tactile sensations, limiting user feedback to a single type of operation sensation.

Innovation Solution

An input device with a spring-mass system and a piezoelectric actuator that controls the duration of the maximum vibration period to produce various tactile sensations by adjusting the timing of voltage application, allowing for independent or combined vibrations to simulate different tactile switch sensations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single vibration waveform pattern is used, then the device structure remains simple, but only one type of tactile sensation can be provided

Engineering Contradiction:
Improvevariety of tactile sensationsVSAvoiddevice structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the vibration waveform changeable over time. A single actuator generates multiple tactile sensations by dynamically switching between different vibration waveform patterns (first, second, and third patterns) with different frequencies and durations, rather than using multiple fixed actuators. This allows one device to provide diverse tactile feedback adaptable to different operation types.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes vibration parameters (frequency, duration, waveform pattern) to produce different tactile sensations. The control unit adjusts the vibration frequency and time length according to the operation type, transforming a single vibration source into multiple sensation types through parameter variation. For example, short high-frequency vibrations simulate click sensations while longer lower-frequency vibrations simulate different tactile feedback.

Inventive Principle:
Principle #35Parameter changes

2Loss of information

If vibration duration is extended, then more tactile information can be conveyed, but the response time becomes slower

Engineering Contradiction:
Improvetactile informationVSAvoidresponse time
Core Design Contradiction:
Loss of informationVSLoss of time

Solution Approach 1:

The patent uses periodic vibration patterns with different frequencies and durations to convey various tactile information. By employing multiple vibration waveform patterns (first pattern with first frequency, second pattern with second frequency, third pattern with third frequency) and controlling their durations, the system transmits rich tactile information through varied periodic vibrations while maintaining rapid response capability.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent maintains continuous useful action by seamlessly switching between different vibration waveform patterns without interruption. The control unit continuously monitors operation types and adjusts vibration patterns in real-time, ensuring uninterrupted tactile feedback delivery. This allows the system to provide appropriate tactile information for each operation type without time loss during transitions.

Inventive Principle:
Principle #20Continuity of useful action

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

Enables the provision of multiple types of tactile sensations by controlling the duration of the maximum vibration period, enhancing user feedback and distinguishing sensations through frequency adjustments within the 100 Hz to 500 Hz range.

Implementation Method 1

an actuator, which is a piezoelectric actuator

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

In an input device that includes a spring-mass system

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

the spring-mass system vibrates at a natural resonance frequency

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3846005B1Input device, control method, and program
Publication Date: 2024.10.16 ALPS ALPINE CO LTD
  • EP3846005B1 patent drawingFigure 1~2
  • EP3846005B1 patent drawingFigure 4(a)~4(b)
  • EP3846005B1 patent drawingFigure 5(a)~5(b)

AI summary

An input device includes an operation part, an actuator configured to impart a tactile effect to the operation part, and a controller configured to apply, to the actuator, a control signal for starting to apply a first vibration to the operation part at a first timing and for starting to apply a second vibration to the operation part at a second timing after the first timing, such that a combined vibration of the first vibration and the second vibration is applied to the operation part. The controller is configured to change the combined vibration to two or more different combined vibrations by changing a control period of time that extends from the first timing to the second timing to two or more different control periods of time.