Magnetic Viscous Fluid Input Device for Silent Haptic Feedback
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Solution Overview
Problem
Existing input devices face challenges in size and noise, with motor-based devices increasing in size and frictional force-based devices generating contact sounds when solids come into contact.
Innovation Solution
The use of a magnetic viscous fluid whose viscosity is changed by a magnetic field to control resistance between moving parts, allowing for a compact and silent operation feeling generation, with a magnetic-field generator creating a field orthogonal to the movement direction and a controller adjusting the magnetic field based on relative position, speed, and acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a motor is used to generate operation feeling, then the operation feeling can be generated, but the size of the input device increases
Solution Approach 1:
The patent replaces the motor-based mechanical system with a magnetic field-based system. The magnetic-field generator creates a magnetic field that interacts with magnetic viscous fluid to generate resistance, eliminating the need for a motor and reducing device size while maintaining operation feeling generation capability
Solution Approach 2:
The patent changes the physical state of the magnetic viscous fluid by applying a magnetic field, which alters the fluid's viscosity parameter. This allows dynamic control of resistance without mechanical moving parts, solving the contradiction between generating operation feeling and maintaining compact size
2Reliability
If frictional force is used to generate operation feeling, then the operation feeling can be generated, but contact sound is generated when solids come into contact
Solution Approach 1:
The patent uses magnetic viscous fluid (a fluid-based system) instead of solid-to-solid contact to generate resistance. The magnetic field alters the fluid's viscosity to create operation feeling without mechanical contact, thereby eliminating contact sounds while maintaining operation feeling generation
Solution Approach 2:
The patent substitutes the friction-based mechanical contact system with a magnetic field-fluid interaction system. This replacement eliminates direct solid contact between moving parts, removing the source of contact sounds while preserving the ability to generate operation feeling through controlled resistance
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 a small, silent input device that can generate various operation feelings by controlling resistance, reducing size compared to motor-based devices and minimizing noise compared to frictional force-based devices.
Implementation Method 1
a magnetic viscous fluid whose viscosity is changed by a magnetic field
Implementation Method 2
a magnetic-field generator that generates a magnetic field
Data Source
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AI summary
An input device 100 includes a first part 200 and a second part 300 configured to move relative to each other according to an input operation, a magnetic viscous fluid 500 that is present in at least a part of a gap between the first part 200 and the second part 300 and a viscosity of which changes according to a magnetic field, and a magnetic-field generator 230 that generates the magnetic field applied to the magnetic viscous fluid 500. The resistance between the first part 200 and the second part 300 rotating relative to each other is changed by changing the magnetic field.