Moving-coil Haptic Actuator with Halbach Array
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Solution Overview
Problem
Existing haptic feedback systems in electronic devices face issues with magnetic interference due to moving magnets, which can lead to inefficient haptic output and potential damage to internal components.
Innovation Solution
The design incorporates a haptic actuator with a movable mass and conduction loop within a ferritic enclosure, utilizing magnetic fields to generate a stronger haptic output while minimizing external magnetic interference through a Halbach array and ferrofluid damping, and includes elastic members for reliable signal transmission and controlled movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If moving magnets are used in the haptic actuator, then haptic output can be generated, but magnetic interference with other components occurs
Solution Approach 1:
The patent extracts the magnet from the moving mass and fixes it to the enclosure, separating the magnetic field generation function from the moving components. This eliminates magnetic interference with other device components while preserving haptic output capability through the interaction between the stationary magnet and the conduction loop on the movable mass.
Solution Approach 2:
Instead of the conventional approach where magnets move with the mass, this patent inverts the configuration by making the magnet stationary and the conduction loop movable. This reversal achieves the same haptic effect through electromagnetic interaction while eliminating the harmful magnetic interference that would occur with moving magnets.
2Reliability
If conventional haptic actuators are used, then haptic feedback is provided, but energy consumption is high and efficiency is low
Solution Approach 1:
The patent replaces traditional mechanical haptic actuation mechanisms with an electromagnetic system consisting of a stationary magnet and a movable conduction loop. This substitution reduces energy consumption and improves efficiency by utilizing electromagnetic forces rather than purely mechanical means to generate haptic feedback.
Solution Approach 2:
The patent optimizes the electromagnetic interaction parameters including the magnetic field strength, conduction loop configuration, and oscillation frequency to achieve efficient energy conversion. By carefully controlling these parameters, the system achieves reliable haptic feedback with reduced energy consumption compared to conventional actuators.
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 enhances the strength and efficiency of haptic feedback with reduced magnetic interference, allowing for a more robust and reliable haptic output with less energy consumption and reduced complexity.
Implementation Method 1
A conduction loop is affixed to the movable mass and is operative to generate a second magnetic field responsive to an electrical current
Implementation Method 2
a conduction elastic member coupled to the enclosure and the conduction loop and configured to convey an electromagnetic signal
Data Source
AI summary
A haptic actuator features magnets coupled to an enclosure and a movable mass with a conduction loop coupled to the enclosure via one or more movement elastic members. One or more conduction elastic members may be used to transmit signals to the conduction loop to cause the movable mass to move bilinearly relative to the enclosure and the magnets. The magnets may consist of a Halbach array to direct magnetic flux toward the conduction loop and away from other device components. Ferrofluid may be included between one or more of the magnets and the conduction loop to act as a damper in the system to improve haptic feedback. Closed loop control, such as back EMF, capacitive sensing, and magnetic sensing, may be included to improve system response.