Piezoelectric Trackpad Assembly for Uniform Localized Haptic Feedback
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Solution Overview
Problem
Existing trackpads lack uniformity in user input and retroactive tactile feedback, with mechanical dome switches providing inconsistent feedback and limited to a single tactile sensation regardless of the device's state.
Innovation Solution
A trackpad system utilizing piezo-electric actuators with a control circuit to generate haptic responses, interpolating user input location, and adjusting feedback strength and type based on pressure and position, enabling contextual and uniform haptic feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical dome switches are used to provide tactile feedback, then retroactive feedback is achieved, but uniformity of input force and feedback strength varies across the trackpad surface
Solution Approach 1:
The patent replaces mechanical dome switches with piezo-electric actuators that convert electrical signals to mechanical deformation. This substitution enables electronic control of haptic feedback, allowing uniform input force across the trackpad surface while maintaining consistent retroactive feedback through electrical signal distribution to multiple actuators.
Solution Approach 2:
The patent divides the trackpad into multiple zones with individual piezo-electric actuators distributed across the surface. Each actuator independently provides haptic feedback for its corresponding zone, enabling localized and uniform feedback control across different regions of the trackpad, eliminating the non-uniformity inherent in single-point mechanical switches.
2Reliability
If mechanical dome switches are used, then tactile feedback is provided, but the feedback is limited to a single sensation regardless of device state
Solution Approach 1:
The patent implements dynamic haptic feedback by controlling piezo-electric actuators with varying electrical signals based on device state, application context, and input characteristics. The system can adjust feedback strength, duration, and pattern dynamically, providing different tactile sensations for different operational contexts rather than a fixed mechanical response.
Solution Approach 2:
The patent changes the parameters of haptic feedback by controlling the electrical signals sent to piezo-electric actuators. By varying voltage, pulse duration, and activation patterns, the system produces diverse tactile sensations including different strengths, frequencies, and temporal patterns, enabling adaptive feedback that responds to different device states and user interactions.
3Ease of operation
If piezo-electric actuators are used with shims to enable deformation, then uniform haptic feedback is achieved, but device complexity increases
Solution Approach 1:
The patent makes the shims multi-functional by designing them to simultaneously serve as structural support elements, deformation enablers for piezo-electric actuators, and potential electrical connection components. This universal design reduces the need for separate components, managing device complexity while achieving uniform haptic feedback across the trackpad surface.
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
Provides enhanced user input uniformity and contextual haptic feedback, allowing for varied haptic sensations based on application and input location, improving the user experience.
Implementation Method 1
a plurality of piezo-electric actuators mounted on a second side of the PCB configured to generate electrical signals in response to a force application by a user on the top touch surface
Implementation Method 2
a plurality of piezo-electric actuators mounted on a second side of the PCB configured to generate electrical signals in response to a force application by a user on the top touch surface, and to provide a haptic response to the user in response to haptic response signals
Data Source
AI summary
A trackpad assembly provides a better uniformity of the user input and the retroactive tactile feedback by providing a plurality of piezo-electric actuators mounted on one side of a PCB configured to generate electrical signals in response to a force application by a user on the top touch surface on another side of the PCB. A control circuit is configured to receive the electrical signals from the plurality of piezo-electric actuators, determine the position of the force application on the top touch surface and generate haptic response signals, which may be targeted based on the position of the force application.