Electromagnetic Actuator Pulse Control for Rich Touchscreen Haptics
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Solution Overview
Problem
Existing touch panel systems fail to effectively convey a wide range of haptic feedback sensations to users, limiting the immersive experience in interactions with touch screens.
Innovation Solution
A vibration presenting device comprising a control device and an electromagnetic actuator that drives a movable part in a linear reciprocating motion, using a combination of main and sub-drive pulses to generate vibrations corresponding to touch operations, allowing for varied haptic feedback without the need for magnets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a vibration actuator is mounted on a back surface of a touch panel via a vibration transmitting part, then vibration can be given to the finger pulp, but the device structure becomes more complex and costs increase
Solution Approach 1:
The patent replaces the traditional mechanical vibration actuator structure with an electromagnetic actuator that uses electromagnetic fields to generate vibration. The electromagnetic actuator includes a coil, magnet, and diaphragm structure that converts electrical energy directly into mechanical vibration without complex mechanical components like motors or eccentric weights, thereby reducing structural complexity while maintaining haptic feedback capability
Solution Approach 2:
The patent changes the operating parameters by using pulse-width modulation (PWM) to control the coil current, enabling precise control of vibration intensity and duration. By adjusting the duty cycle and frequency of the PWM signal, the system can generate various vibration patterns (continuous, intermittent, varying intensity) without requiring multiple physical actuators, thus reducing overall device complexity
2Ease of operation
If multiple components (voice coil motor, support part, damper, spring) are provided in parallel, then vibration can be generated, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent merges multiple functional components into an integrated electromagnetic actuator assembly. The coil, magnet, diaphragm, and support structure are combined into a single compact unit where the diaphragm serves both as the vibration-generating surface and as part of the electromagnetic circuit. This integration eliminates the need for separate dampers and springs, simplifying the assembly process and reducing manufacturing complexity
Solution Approach 2:
The diaphragm in the electromagnetic actuator performs multiple functions simultaneously: it acts as the electromagnetic armature, the vibration-generating surface, and the structural support element. This multi-functionality reduces the total number of components needed, making the device easier to manufacture and assemble while maintaining full vibration generation capability
3Power
If magnets are used in the electromagnetic actuator, then strong electromagnetic force can be generated, but the cost and device complexity increase
Solution Approach 1:
The patent uses a cost-effective electromagnetic actuator design that employs standard off-the-shelf components like conventional coils and readily available magnets. The design accepts that these components have limited lifetimes but compensates through reasonable durability engineering, reducing overall system cost while maintaining sufficient power output for haptic feedback applications
Solution Approach 2:
The patent optimizes the electromagnetic force generation by carefully selecting and adjusting parameters such as coil turns, current density, and magnet strength to achieve the required force output without using excessive or expensive materials. The PWM control technique also allows efficient use of electrical power, reducing the need for oversized components
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 expression of diverse touch operation feelings, providing a more intuitive and immersive user experience by accurately simulating the sensation of interacting with mechanical switches and other controls on touch screens, while reducing costs and complexity.
Implementation Method 1
an electromagnetic actuator including a coil that generates a magnetic field in response to supply of a drive current
Implementation Method 2
a movable part that is supported elastically with respect to a fixing part
Data Source
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AI summary
Provided is a control device for controlling an electromagnetic actuator that vibrates an operation device by driving the operation device supported by an elastic support part so as to be elastically vibrated in one direction in a vibrating direction thereof, the control device comprising: a current pulse supply unit configured to supply a driving current pulse to a coil of the electromagnetic actuator as a driving current for driving the operation device in accordance with a touch operation of the operation device, wherein the current pulse supply unit supplies the drive current pulse capable of starting the elastic vibration as a main driving current pulse, and then supplies the drive current pulse capable of adjusting attenuation period of the elastic vibration as a sub-driving current pulse.