WO2022027248A1

WO2022027248A1 - Haptic feedback arrangement

Info

Publication number: WO2022027248A1
Application number: PCT/CN2020/106874
Authority: WO
Inventors: Grigori Evreinov; Patrick COE; Roope Raisamo
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2020-08-04
Filing date: 2020-08-04
Publication date: 2022-02-10
Also published as: EP4176332A4; CN116261703A; EP4176332A1

Abstract

A haptic feedback arrangement (1) comprising at least one haptic signal generating element (2) extending in a main plane (P1), and at least one actuator (3) coupled to the haptic signal generating element (2). The actuator (3) is configured to displace an area of the haptic signal generating element (2) in a direction (D1) perpendicular to the main plane (P1) by generating a transverse wave, the transverse wave propagating from the area and along a longitudinal axis (A1) of the haptic signal generating element (2). This solution allows one actuator to generate displacement of an element along its entire length or area by allowing a transverse wave to travel across that length or area, facilitating a reduction in the number of actuators necessary as well as constructive interference between multiple signals. The displacement may be induced at frequencies which allow efficient vibrations with regards to human sensitivity.

Description

HAPTIC FEEDBACK ARRANGEMENT

TECHNICAL FIELD

The disclosure relates to a haptic feedback arrangement comprising at least one actuator.

BACKGROUND

The main interaction surfaces of mobile devices are equipped with touch-sensitive input electronic components such as buttons, strips, pads and other surfaces scattered around the periphery of the device, e.g. power and volume control. The back and sides surfaces of most devices, and corresponding protective cases, are inert surfaces which do not interact with the hand of a user holding the device wile interacting via the touchscreen.

Being able to interact with the back and sides of a device, or accessories, would reduce clutter and obstruction of visual elements by the hand. However, touch sensitive input on the back and sides of a device must not be confused with regular handling or squeezing of the device. Advances in haptic technology support the development of this interaction space by allowing the tactile information that users can perceive to be enhanced. Still, here are challenges in delivering haptic feedback having high enough definition for the user to be able to detect an exact location without visual cues.

Furthermore, current actuator technology cannot deliver continuous feedback without adverse resonant effects and is limited to discrete impulses for so called active edge feedback. Active edge technology utilizes a plurality of actuators distributed across the device. This allows the haptic device to function alone as a display for haptic notifications, or with a graphical user interface to augment interaction and provide haptic feedback dynamically with different resolutions and speeds. However, this increases power consumption, requires more complex control technology, and increases the risk of manufacturing errors due to the precise mechanics involved in the assembly.

SUMMARY

It is an object to provide a haptic feedback arrangement. The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description, and the figures.

According to a first aspect, there is provided a haptic feedback arrangement, the arrangement comprising at least one haptic signal generating element extending in a main plane, and at least one actuator coupled to the haptic signal generating element, the actuator being configured to displace an area of the haptic signal generating element in a direction perpendicular to the main plane by generating a transverse wave, the transverse wave propagating from the area and along a longitudinal axis of the haptic signal generating element.

This solution allows one actuator to generate displacement of an element along its entire length or area by letting a transverse wave travel across that length or area. This allows the number of actuators to be minimized, allowing extra free space and reduced energy consumption. Furthermore, by separating actuation (force generating) and tactile stimulation, it is possible to achieve high-definition multi-point haptic feedback, increased signal control, increased haptic signal transfer efficiency, and constructive interference between multiple signals.

In a possible implementation form of the first aspect, the haptic signal generating element is elongated in at least one direction, such that the transverse wave may propagate in that direction.

In a further possible implementation form of the first aspect, displacement is generated at frequencies which allow efficient vibrations to be generated based on human sensitivity.

In a further possible implementation form of the first aspect, the haptic signal generating element comprises at least one seismic mass element. Such a configuration allows high-fidelity tactile patterns while still minimizing the number of actuators, energy consumption, and simplifying their control.

In a further possible implementation form of the first aspect, the haptic signal generating element comprises a plurality of seismic mass elements, the seismic mass elements being distributed along the longitudinal axis of the haptic signal generating element, each seismic mass element being separated from adjacent seismic mass element (s) by a gap. By providing a plurality of masses, the transverse wave is allowed to propagate by individual displacement of each mass sequentially. The propagation of the transverse wave focuses the user’s attention to a specific area of skin contact.

In a further possible implementation form of the first aspect, the seismic mass elements have identical shapes, the shape preferably being one of spherical, cylindrical, ellipsoidal, polyhedral, or freeform.

In a further possible implementation form of the first aspect, the haptic feedback arrangement further comprises a connection element configured to interconnect adjacent seismic mass elements of one haptic signal generating element, the connection element being an elastic element extending coaxially with the longitudinal axis of the haptic signal generating element, or configured to interconnect adjacent seismic mass elements of adjacent haptic signal generating elements, the connection element being an elastic element extending perpendicular to the longitudinal axes of the haptic signal generating elements and coplanar with the main plane. The connection element limits the displacement of the seismic mass elements, and helps to normalize the transfer of mechanical energy along the haptic signal generating element with predictable attenuation.

In a further possible implementation form of the first aspect, the connection element allows the transverse wave to propagate from one seismic mass element to an adjacent seismic mass element.

In a further possible implementation form of the first aspect, the connection element extends colinearly with the haptic signal generating element, allowing the transverse wave to propagate most efficiently.

In a further possible implementation form of the first aspect, the connection element comprises a smart material, preferably one of an electromechanical polymer-metal composite or alloy, an electro active materials, a photoactive material, a temperature active material, and a magnetoactive material, making the mechanical properties of the haptic feedback arrangement easier to adjust and control.

In a further possible implementation form of the first aspect, the haptic feedback arrangement further comprises at least one spacer element configured to limit displacement of the seismic mass element with respect to adjacent seismic mass elements of the same haptic signal generating element, and/or to limit displacement of the seismic mass element with respect to seismic mass elements of an adjacent haptic signal generating element.

In a further possible implementation form of the first aspect, the spacer element is an elastic element extending perpendicular to the longitudinal axis of the haptic signal generating element and non-coplanar with the main plane.

In a further possible implementation form of the first aspect, the spacer element is configured to interconnect adjacent seismic mass elements of adjacent haptic signal generating elements. This allows the transverse wave to propagate in more than one direction.

In a further possible implementation form of the first aspect, at least one of the connection element and the spacer element has a predetermined spring coefficient and a predefined damping coefficient, allowing the elements to be configured in any suitable way to generate e.g. a specific frequency and amplitude of the transverse wave. Furthermore, this allows high-fidelity stimulation of the users skin at a particular assigned location, while dampening the transverse wave, i.e. vibration signals, in the surrounding interface surface.

In a further possible implementation form of the first aspect, the actuator is coupled to at least one seismic mass element of the haptic signal generating element by means of a contact coupling or a non-contact coupling, increasing the flexibility of the haptic feedback arrangement.

In a further possible implementation form of the first aspect, the contact coupling comprises mechanical linkage, the mechanical linkage optionally comprising a hydraulic connection or an ultrasonic connection

In a further possible implementation form of the first aspect, the non-contact coupling comprises a magnetic connection or a magnetic field connection, the magnetic connection or the magnetic field connection optionally comprising a pressure connection or a pneumatic connection.

In a further possible implementation form of the first aspect, the actuator is an electromagnetic actuator or a piezoelectric actuator.

In a further possible implementation form of the first aspect, the haptic feedback arrangement comprises a first actuator and a second actuator coupled to the at least one haptic signal generating element, the first actuator generating a first transverse wave propagating along the haptic signal generating element in a first propagation direction, the second actuator generating a second transverse wave propagating along the haptic signal generating element in a second propagation direction, the second propagation direction being opposite to the first propagation direction, such that the first transverse wave and the second transverse wave interfere constructively.

In a further possible implementation form of the first aspect, the haptic feedback arrangement comprises a plurality of actuators and a plurality of haptic signal generating elements, each actuator being coupled to at least one haptic signal generating element, and each haptic signal generating element being coupled to at least one actuator. This allows the configuration of the haptic feedback arrangement to be maximally flexible.

According to a second aspect, there is provided a tactile device comprising a haptic feedback arrangement according to the above, and a material volume configured to be in tactile contact with a user of the tactile display device, the haptic signal generating element (s) of the haptic feedback arrangement being at least partially embedded in the material volume such that the longitudinal axis of each haptic signal generating element is coplanar with a main plane of the material volume, such that propagation of a transverse wave along the longitudinal axis of the haptic signal generating element generates displacement of the material volume in the direction perpendicular to the main plane.

This solution allows one actuator to generate displacement of a user contact surface along its entire length or area by letting a transverse wave travel across that length or area. This allows the number of components to be minimized, allowing extra free space within the device and/or size reduction of the device, as well as reduced energy consumption. Furthermore, the haptic signal generating element is carried and supported by the material volume.

In a possible implementation form of the second aspect, he connection element of the haptic feedback arrangement is configured to interconnect the seismic mass element of the haptic signal generating element with the material volume. This limits the displacement of the seismic mass elements, and helps to normalize the transfer of mechanical energy with predictable attenuation.

In a further possible implementation form of the second aspect, the spacer element of the haptic feedback arrangement is configured to limit displacement of the seismic mass elements of the haptic signal generating element with respect to the material volume. By limiting the range of displacement, the material volume is not at risk of becoming damaged by too large displacement.

In a further possible implementation form of the second aspect, the gaps separating adjacent seismic mass element (s) of the haptic signal generating element are filled with material of the material volume, providing additional spring and/or dampening effect to the haptic feedback arrangement.

In a further possible implementation form of the second aspect, the tactile device is one of a VR haptic headset, a wearable, a smartphone, a tablet, or a laptop.

In a further possible implementation form of the second aspect, the material volume is one of a casing for an electronic device, the fabric of a haptic garment, or the material of a steering wheel covering.

In a further possible implementation form of the second aspect, the material volume comprises a polymer material, allowing the haptic feedback arrangement to be overmolded by material volume and facilitating a durable and thin tactile device.

This and other aspects will be apparent from the embodiments described below.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present disclosure, the aspects, embodiments and implementations will be explained in more detail with reference to the example embodiments shown in the drawings, in which:

Fig. 1 shows a schematic side view of a haptic feedback arrangement in accordance with one embodiment of the present invention;

Figs. 2a and 2b show partial side views of two haptic feedback arrangements in accordance with two embodiments of the present invention;

Figs. 3a and 3b show cross-sectional side views of two haptic feedback arrangements in accordance with two embodiments of the present invention;

Fig. 4 shows a schematic side view of a haptic feedback arrangement in accordance with one embodiment of the present invention;

Figs. 5a and 5b show schematic illustrations of the spring and dampening functions of the connection element and spacer element of the haptic feedback arrangement in accordance with embodiments of the present invention;

Fig. 6 shows a schematic top view of a haptic feedback arrangement in accordance with one embodiment of the present invention;

Figs. 7a and 7b show schematic top views of haptic signal generating elements in accordance with embodiments of the present invention;

Fig. 8 shows a schematic top view of a haptic signal generating element in accordance with embodiments of the present invention, the haptic signal generating element being arranged in a two-or three-dimensional material grid;

Figs. 9a to 11b show cross-sectional top views and cross-sectional side views of embodiments of tactile devices in accordance with embodiments of the present invention;

Figs. 12a to 12e show schematic illustrations of tactile devices in accordance with further embodiments of the present invention.

DETAILED DESCRIPTION

Figs. 9a to 12e show embodiments of tactile devices 8 comprising a haptic feedback arrangement 1, described in more detail below, and a material volume 9 configured to be in tactile contact with a user of the tactile device 8.

The tactile device may be a tactile display device, such as a VR haptic headset as shown in Fig. 12b, a wearable as shown in Fig. 12a, a smartphone as shown in Figs. 9a-9b, a tablet, or a laptop. Furthermore, the tactile arrangement 1 may be arranged not in a display device but in a material volume 9 which also functions as, or form, a casing for any electronic device, as shown in Figs. 10a-11b, the fabric of a haptic garment as shown in Figs. 12d and 12e, or the material of a steering wheel covering as shown in Fig. 12c. The material volume 9 may comprise a polymer material.

Figs. 1 to 4 show embodiments of the above-mentioned haptic feedback arrangement 1. The arrangement 1 comprises at least one haptic signal generating element 2 extending in a main plane P1, and at least one actuator 3 coupled to the haptic signal generating element 2. As shown in Figs. 1, 6, and 9a to 12e, each haptic signal generating element 2 may be coupled to two actuators 3.

Each actuator 3 is configured to displace an area of the haptic signal generating element 2 in a direction D1 perpendicular to the main plane P1 by generating a haptic signal in the form of a transverse wave, as indicated in Fig. 1. The transverse wave propagates from the area, and along the longitudinal axis A1 of the haptic signal generating element 2. The displaced area may correspond to the area of the haptic signal generating element 2 which is coupled to the actuator 3. The actuator 3 may be an electromagnetic actuator or a piezoelectric actuator.

The haptic signal generating element 2 may comprise at least one seismic mass element 4. The seismic mass elements 4 may have identical shapes, and the shape may be spherical, as shown in Figs 1 to 6 and 9a to 12e, cylindrical, ellipsoidal as shown in Fig. 7a, polyhedral, or freeform as shown in Fig 7b.

The haptic signal generating element 2 may have an elongated shape, as shown in Figs. 1 to 4 and 6 to 12e. The elongated shape may be achieved by means of a plurality of sequentially arranged seismic mass elements 4, the seismic mass elements 4 being distributed along the longitudinal axis A1 of the haptic signal generating element 2.

The seismic mass element 4 may be arranged tightly in abutment with each other, preferably interconnecting a shown in Fig 7b. Each seismic mass element 4 may also be separated from adjacent seismic mass elements 4 by a gap 5, as shown in Figs. 3a to 3b, 7a, and 8. The gaps 5 separating adjacent seismic mass elements 4 of the haptic signal generating element 2 may be filled with material of the material volume 9.

A connection element 6 may be provided to interconnect adjacent seismic mass elements 4 of one haptic signal generating element 2, as shown in Figs 3b and 6. The connection element 6 allows the transverse wave to propagate from the above-mentioned area of the haptic signal generating element 2, and along the longitudinal axis A1 of the haptic signal generating element 2, from one seismic mass element 4 to an adjacent seismic mass element 4. As each seismic mass element 4 is being sequentially displaced in direction D1, i.e. perpendicular to longitudinal axis A1, as the transverse wave reaches it.

The connection element 6 is flexible and may be an elastic element extending coaxially with the longitudinal axis A1 of the haptic signal generating element 2. The connection element 6 may furthermore extend colinearly with the haptic signal generating element 2. Furthermore, one or several connection elements 6 may be used to interconnect adjacent seismic mass elements 4 of adjacent haptic signal generating elements 2 (not shown) , the connection element 6 being an elastic element extending perpendicular to the longitudinal axes A1 of the haptic signal generating elements 2 and coplanar with the main plane P1. The tactile connection element 6 may also be configured to interconnect the seismic mass element 4 with the material volume 9.

The connection element 6 may comprise a smart material, i.e. materials that sense and react to environmental conditions or stimuli such as mechanical, chemical, electrical, or magnetic signals. The smart material may be any suitable material, but preferably one of an electromechanical polymer-metal composite or alloy, an electro active materials, a photoactive material, a temperature active material, and a magnetoactive material. The smart material allows the mechanical properties of the haptic feedback arrangement to be easily adjustable and controllable.

The haptic feedback arrangement 1 may further comprise at least one spacer element 10 configured to limit displacement of a seismic mass element 4 with respect to adjacent seismic mass elements 4 of the same haptic signal generating element 2, as shown in Figs 3a and 3b. Correspondingly, the spacer element 10 may be configured to limit displacement of a seismic mass element 4 with respect to seismic mass elements 4 of an adjacent haptic signal generating element 2 (not shown) . The spacer elements 10 may also be configured to interconnect adjacent seismic mass elements 4 of adjacent haptic signal generating elements 2. Furthermore, the spacer element 10 may be configured to limit displacement of the seismic mass elements 4 with respect to the material volume 9.

The spacer element 10 may be an elastic element extending perpendicular to the longitudinal axis A1 of the haptic signal generating element 2 and non-coplanar with the main plane P1. One spacer element 10 may be provided in each gap 5 as shown in Fig. 5a, or in a selected number of gaps 5 as shown in Fig. 3b.

At least one of the connection element 6 and the spacer element 10 may have a predetermined spring coefficient and a predefined damping coefficient, as illustrated in Figs. 5a and 5b. The spring coefficients and damping coefficients can be chosen, together with the material of the material volume 9 in order to adjust the wave propagation as desired.

The actuator 3 may be coupled to one or several seismic mass elements 4 of the haptic signal generating element 2 by means of a contact coupling 7a as illustrated schematically in Fig. 2a or a non-contact coupling 7b as illustrated schematically in Fig 2b.

The contact coupling 7a may comprise mechanical linkage. The mechanical linkage may comprise a hydraulic connection or an ultrasonic connection, the actuator 3 generating fluid waves or ultrasonic waves traveling through said mechanical linkage to the haptic signal generating element 2.

The non-contact coupling 7b may comprise a magnetic connection or a magnetic field connection. The magnetic connection or the magnetic field connection may comprise a pressure connection or a pneumatic connection, the actuator 3 generating pressure waves or pulses traveling across the air gap between the actuator and the haptic signal generating element 2.

As shown in Figs 10a to 12e, the haptic feedback arrangement 1 may comprise a plurality of actuators 3 and a plurality of haptic signal generating elements 2. Each actuator 3 may be coupled to at least one haptic signal generating element 2, and each haptic signal generating element 2 may be coupled to at least one actuator 3. By synchronizing the time or /and phase of actuation of the individual actuators 3, or delay the actuation of individual actuators 3 with regards to the other actuators 3, constructive interference between transverse waves may be achieved at any desired area along the haptic signal generating element. 2

The haptic feedback arrangement 1 may comprise a first actuator 3 and a second actuator 3 coupled to the at least one haptic signal generating element 2, as shown in Fig. 6. The first actuator 3 generates a first transverse wave propagating along the haptic signal generating element 2 in a first propagation direction D2. Correspondingly, the second actuator 3 generates a second transverse wave propagating along the haptic signal generating element 2 in a second propagation direction D3. The second propagation direction D3 is opposite to the first propagation direction D2, such that the first transverse wave and the second transverse wave can interfere constructively and strengthen the signal, i.e. increase the amplitude of the transverse wave at least at a local interference maximum.

As shown in Fig. 12b, each haptic signal generating element 2 may be coupled to only one actuator 3.

As shown in Figs. 9a to 10b and 12a to 12e, each haptic signal generating element 2 may be coupled to a first actuator 3 and a second actuator 3, one at approximately each end of the haptic signal generating element 2. The haptic signal generating elements 2 may extend in parallel across the material volume 9.

As shown in Figs. 11a, 11b, 12d, and 12e, the haptic signal generating elements 2 may also extend at angles to each other, such that the material volume 9 is still covered but with of fewer haptic signal generating elements 2, e.g. by using diagonally extending haptic signal generating elements 2. With such a configuration, each actuator 3 may be connected to several haptic signal generating elements 2, also reducing the number of actuators 3 necessary.

The haptic signal generating element (s) 2 of the haptic feedback arrangement 1 may be at least partially embedded in the material volume 9 such that the longitudinal axis A1 of each haptic signal generating element 2 is coplanar with the main plane P2 of the material volume 9, as shown in Figs. 1 to 4 and 9b.

The haptic signal generating element (s) 2 of the haptic feedback arrangement 1 may also be arranged adjacent the material volume 9 such that the longitudinal axis A1 of each haptic signal generating element 2 is parallel, but not coplanar with the main plane P2 of the material volume 9, as shown in Figs. 10 b and 11b.

Propagation of the transverse wave along the longitudinal axis A1 of the haptic signal generating element 2 generates displacement of the material volume 9 in the direction D1 perpendicular to the main plane P2.

The tactile device 8 may further comprise a haptic microcontroller wireless interface with host controller and drivers, as well as a power source such as a battery (not shown) .

The various aspects and implementations have been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed subject-matter, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.

The reference signs used in the claims shall not be construed as limiting the scope. Unless otherwise indicated, the drawings are intended to be read (e.g., cross-hatching, arrangement of parts, proportion, degree, etc. ) together with the specification, and are to be considered a portion of the entire written description of this disclosure. As used in the description, the terms “horizontal” , “vertical” , “left” , “right” , “up” and “down” , as well as adjectival and adverbial derivatives thereof (e.g., “horizontally” , “rightwardly” , “upwardly” , etc. ) , simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate.

Claims

A haptic feedback arrangement (1) , said arrangement (1) comprising:

-at least one haptic signal generating element (2) extending in a main plane (P1) , and

-at least one actuator (3) coupled to said haptic signal generating element (2) , said actuator (3) being configured to displace an area of said haptic signal generating element (2) in a direction (D1) perpendicular to said main plane (P1) by generating a transverse wave, said transverse wave propagating from said area and along a longitudinal axis (A1) of said haptic signal generating element (2) .
The haptic feedback arrangement (1) according to claim 1, wherein said haptic signal generating element (2) comprises at least one seismic mass element (4) .
The haptic feedback arrangement (1) according to claim 2, wherein said haptic signal generating element (2) comprises a plurality of seismic mass elements (4) , said seismic mass elements (4) being distributed along said longitudinal axis (A1) of said haptic signal generating element (2) ,

each seismic mass element (4) being separated from adjacent seismic mass element (s) (4) by a gap (5) .
The haptic feedback arrangement (1) according to claim 3, further comprising a connection element (6) configured to interconnect adjacent seismic mass elements (4) of one haptic signal generating element (2) , said connection element (6) being an elastic element extending coaxially with said longitudinal axis (A1) of said haptic signal generating element (2) , or

configured to interconnect adjacent seismic mass elements (4) of adjacent haptic signal generating elements (2) , said connection element (6) being an elastic element extending perpendicular to said longitudinal axes (A1) of said haptic signal generating elements (2) and coplanar with said main plane (P1) .
The haptic feedback arrangement (1) according to claim 4, wherein said connection element (6) comprises a smart material, preferably one of an electromechanical polymer-metal composite or alloy, an electro active materials, a photoactive material, a temperature active material, and a magnetoactive material.
The haptic feedback arrangement (1) according to any one of claims 3 to 5, further comprising at least one spacer element (10) configured to limit displacement of said seismic mass element (4) with respect to adjacent seismic mass elements (4) of the same haptic signal generating element (2) , and/or

to limit displacement of said seismic mass element (4) with respect to seismic mass elements (4) of an adjacent haptic signal generating element (2) .
The haptic feedback arrangement (1) according to claim 6, wherein said spacer element (10) is an elastic element extending perpendicular to said longitudinal axis (A1) of said haptic signal generating element (2) and non-coplanar with said main plane (P1) .
The haptic feedback arrangement (1) according to any one of the previous claims, wherein said actuator (3) is coupled to at least one seismic mass element (4) of said haptic signal generating element (2) by means of a contact coupling (7a) or a non-contact coupling (7b) .
The haptic feedback arrangement (1) according to claim 8, wherein said contact coupling (7a) comprises mechanical linkage, said mechanical linkage optionally comprising a hydraulic connection or an ultrasonic connection.
The haptic feedback arrangement (1) according to claim 8 or 9, wherein said non-contact coupling (7b) comprises a magnetic connection or a magnetic field connection, said magnetic connection or said magnetic field connection optionally comprising a pressure connection or a pneumatic connection.
The haptic feedback arrangement (1) according to any one of the previous claims, wherein said actuator (3) is an electromagnetic actuator or a piezoelectric actuator.
The haptic feedback arrangement (1) according to any one of the previous claims, comprising a first actuator (3) and a second actuator (3) coupled to the at least one haptic signal generating element (2) ,

said first actuator (3) generating a first transverse wave propagating along said haptic signal generating element (2) in a first propagation direction (D2) ,

said second actuator (3) generating a second transverse wave propagating along said haptic signal generating element (2) in a second propagation direction (D3) , said second propagation direction (D3) being opposite to said first propagation direction (D2) , such that said first transverse wave and said second transverse wave interfere constructively.
The haptic feedback arrangement (1) according to any one of the previous claims, comprising a plurality of actuators (3) and a plurality of haptic signal generating elements (2) , each actuator (3) being coupled to at least one haptic signal generating element (2) , and each haptic signal generating element (2) being coupled to at least one actuator (3) .
A tactile device (8) comprising a haptic feedback arrangement (1) according to any one of claims 1 to 13, and a material volume (9) configured to be in tactile contact with a user of said tactile display device,

the haptic signal generating element (s) (2) of said haptic feedback arrangement (1) being at least partially embedded in said material volume (9) such that the longitudinal axis (A1) of each haptic signal generating element (2) is coplanar with a main plane (P2) of said material volume (9) ,

such that propagation of a transverse wave along said longitudinal axis (A1) of said haptic signal generating element (2) generates displacement of said material volume (9) in the direction (D1) perpendicular to said main plane (P2) .
The tactile device (8) according to claim 14, wherein the connection element (6) of said haptic feedback arrangement (1) is configured to interconnect the seismic mass element (4) of said haptic signal generating element (2) with said material volume (9) .
The tactile device (8) according to claim 15 or 15, wherein the spacer element (10) of said haptic feedback arrangement (1) is configured to limit displacement of the seismic mass elements (4) of said haptic signal generating element (2) with respect to said material volume (9) .
The tactile device (8) according to any one of claims 14 to 16, wherein gaps (5) separating adjacent seismic mass element (s) (4) of said haptic signal generating element (2) are filled with material of said material volume (9) .
The tactile device (8) according to any one of claims 14 to 17, wherein said tactile device (8) is one of a VR haptic headset, a wearable, a smartphone, a tablet, or a laptop.