Haptic Input Device Actuator Mounting for Vibration Control

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Solution Overview

Problem

Existing touch-sensitive input devices suffer from secondary vibrations during haptic feedback generation, leading to structure-borne noise and space inefficiency, as the actuator is directly supported on a thermoplastic carrier, causing unwanted vibrations and rotational movements.

Innovation Solution

A touch-sensitive input device design featuring an additional body with higher mass density, an electromagnetic actuator, and an absorber body decouples haptic feedback from the carrier, positioning the actuator's axis close to the center of gravity to minimize rotational vibrations and optimize space usage, with elastic bearing means and a vibration damper to control deflection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the actuator is supported directly on the thermoplastic carrier, then the device structure is simple and installation space is reduced, but secondary vibrations occur causing structure-borne noise and disturbing vibrations

Engineering Contradiction:
Improvedevice structureVSAvoidsecondary vibrations
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The device is segmented into distinct functional modules: the carrier, the absorber body, and the input part with additional body are separated as independent components. This segmentation allows the actuator to be mounted on the absorber body rather than directly on the carrier, isolating vibration sources and enabling independent optimization of each module's function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The absorber body serves as an intermediary component between the actuator and the carrier. It decouples the actuator from direct contact with the thermoplastic carrier, thereby preventing the transmission of secondary vibrations and structure-borne noise while still allowing the actuator to function effectively.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the actuator is positioned away from the center of gravity, then haptic feedback can be generated, but rotational vibrations and unwanted excitations occur

Engineering Contradiction:
Improvehaptic feedback generationVSAvoidrotational vibrations
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The additional body acts as a counterweight component that shifts the center of gravity of the input part assembly. By strategically positioning and sizing the additional body, the center of gravity is adjusted to align with the actuator's axis of action, thereby eliminating rotational vibrations and unwanted excitations during haptic feedback generation.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

3Object-generated harmful factors

If the absorber body is made from metal with higher mass density, then secondary vibrations are reduced, but the weight of the input device increases

Engineering Contradiction:
Improvesecondary vibrationsVSAvoidinput device weight
Core Design Contradiction:
Object-generated harmful factorsVSWeight of moving object

Solution Approach 1:

Instead of making the entire input device heavy, the high mass density metal is applied locally only to the absorber body where it is most needed for vibration reduction. This localized application of heavy material achieves the vibration damping effect while minimizing the overall weight increase of the device.

Inventive Principle:
Principle #3Local quality

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 design effectively reduces secondary vibrations, enhances haptic feedback reproducibility, and achieves a space-saving, vibration-optimized input device with minimal rotational excitation, providing clear and controlled haptic feedback.

Implementation Method 1

an electromagnetic actuator (4), in particular a coil, whose electromagnetic field generated by the coil is designed and arranged to interact with an armature (5)

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

an absorber body (6) which is mounted on the carrier (3) so that it can move at least along the deflection direction by means of second bearing means (9)

Methodology Applied
Scientific EffectVibration absorption: Damping

Data Source

PatentEP3475788B1Touch sensitive input device with improved haptic feedback
Publication Date: 2021.08.11 PREH GMBH
  • EP3475788B1 patent drawingFigure 1

AI summary

The invention relates to a touch-sensitive input device (1), having: a support (3); a touch-sensitive input part (2), such as a touchpad or a touchscreen, and a supplementary body (7, 8) that is rigidly connected to the input part (2) and that is mounted on the support (3) by means of first bearing means (10) so as to be movable together in at least one deflection direction; a damper body (6) that is mounted on the support (3) by means of second bearing means (9) so as to be movable at least in the deflection direction, an actuator (4), acting between the damper body (6) and the combination of input part (2) and supplementary body (7, 8), having an effective axis (W), in order to cause a movement by the input part (3) substantially oppositely to the damper body (4) to generate haptic feedback, wherein the input part (2) and the supplementary body (7, 8) define a hollow volume (11) in which at least the actuator (4) is arranged.