Haptic Multi-Function Button With Proximity Sensing

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Solution Overview

Problem

Existing electronic devices with physical buttons require direct line of sight for operation, leading to increased power consumption and user ambiguity regarding button functions, especially in devices with limited button visibility or multiple functions per button.

Innovation Solution

A button comprising a mechanical switch actuator, an electromagnetic sensor for touch and proximity detection, and a responsive material structure for haptic feedback, allowing function-specific feedback without the need for direct line of sight and reducing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If visual feedback cues are displayed on buttons or display, then user understanding of button function is improved, but power consumption increases and line of sight is required

Engineering Contradiction:
Improvebutton function informationVSAvoidpower consumption
Core Design Contradiction:
Loss of informationVSUse of energy by moving object

Solution Approach 1:

The patent replaces visual feedback mechanisms (display screens, illuminated buttons) with a haptic feedback system using electroactive polymer material. This substitution eliminates the need for visual cues while providing tactile feedback that communicates button function and state to the user through touch, thereby reducing power consumption and removing the line-of-sight requirement.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediary haptic feedback layer between the user and the button. This intermediate layer, composed of electroactive polymer material, translates electrical signals into tactile sensations that convey functional information about the button, serving as a mediator that provides information without requiring visual display or increasing power consumption significantly.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If multiple functions are assigned to a single button, then device complexity is reduced, but user ambiguity about which function will be triggered increases

Engineering Contradiction:
Improvenumber of buttonsVSAvoidfunction identification clarity
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The patent implements a feedback mechanism where the haptic properties of the electroactive polymer material change dynamically based on the current function assigned to the button. Different functions produce distinct tactile sensations (varying in stiffness, responsiveness, or vibration patterns), providing the user with immediate tactile information about which function will be triggered, thereby eliminating ambiguity while maintaining multiple functions per button.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies local quality by making the haptic characteristics of the button surface variable and context-dependent. Different regions or states of the button material exhibit different mechanical properties (stiffness, elasticity, damping) that correspond to different functions, allowing the user to distinguish between multiple functions through localized tactile cues without needing additional physical buttons.

Inventive Principle:
Principle #3Local quality

3Loss of information

If haptic feedback is provided continuously, then user feedback on button function is improved, but power consumption increases

Engineering Contradiction:
Improvebutton function feedbackVSAvoidpower consumption
Core Design Contradiction:
Loss of informationVSUse of energy by moving object

Solution Approach 1:

The patent employs periodic or event-triggered activation of the haptic feedback system rather than continuous operation. The electroactive polymer material is activated only when the user interacts with the button or when the system state changes, providing feedback at relevant moments while remaining inactive during normal operation. This periodic action maintains effective feedback communication while significantly reducing overall power consumption compared to continuous haptic feedback.

Inventive Principle:
Principle #19Periodic 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

The solution provides unambiguous haptic feedback for button functions, reduces power consumption, and enables multiple functions on a single button without disturbing content consumption or increasing power usage.

Implementation Method 1

an electromagnetic sensor for sensing touch and/or proximity of an object interacting with the button

Methodology Applied
Scientific EffectElectromagnetic sensing: Electromagnetic Induction

Implementation Method 2

a responsive material structure for providing haptic feedback to the object

Methodology Applied
Scientific EffectElectroactive material response: Electroactive Polymer

Data Source

PatentEP4305507B1Button with mechanical switch, electromagnetic sensor and haptic feedback, and method
Publication Date: 2025.06.25 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP4305507B1 patent drawingFigure 1~2
  • EP4305507B1 patent drawingFigure 3
  • EP4305507B1 patent drawingFigure 4

AI summary

A method, performed by an electronic device for triggering a function of the electronic device, wherein the electronic device comprises a button which comprises a mechanical switch actuator for triggering a function related to the button, an electromagnetic sensor for sensing touch and/or proximity of an object interacting with the button and a responsive material structure for providing haptic feedback to the object is provided. The electronic device senses (401) touch and/or proximity of the object with the electromagnetic sensor. The electronic device generates (404) a haptic feedback with the responsive material structure in response to sensing the touch and/or proximity of the object. The haptic feedback is associated with the function which is triggered by the mechanical switch actuator. The electronic device triggers the function in response to the mechanical switch actuator being actuated.