Haptic component comprising a piezoelectric actuator and reinforcement elements
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- TDK ELECTRONICS AG
- Filing Date
- 2024-06-28
- Publication Date
- 2026-05-06
AI Technical Summary
Existing haptic components with piezoelectric actuators face issues with excessive deformation and potential damage due to concentrated force application, leading to instability and damage when subjected to high forces, particularly in applications like touchscreens and automotive systems.
A haptic component design featuring a piezoelectric actuator with a reinforcing element having a stop structure with alternating stop and non-stop areas, which distributes force more evenly and prevents excessive deformation by increasing the contact area at the edge regions, thereby enhancing stability and preventing damage.
The design effectively distributes force over a larger surface area, preventing damage to the actuator and reinforcing element even at higher forces, ensuring reliable operation and extended lifespan, suitable for forces up to 400 N without causing damage.
Smart Images
Figure EP2024068251_02012025_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] HAPTIC COMPONENT WITH PIEZOELECTRIC ACTUATOR AND AMPLIFIER ELEMENTS
[0003] The present invention relates to a haptic component for generating a haptic signal. Such a device comprises an actuator that generates a movement of a movable element. The movable element is designed, for example, as a touch-sensitive surface or tip of a pen-like device. The actuator is, for example, a piezoelectric actuator, in particular a piezoceramic actuator.
[0004] The haptic component can be designed to generate haptic feedback upon contact. The haptic component can be used, for example, in a touchscreen, trackpad, push button, or stylus (pen-like device). In particular, the haptic component can be used in the automotive sector.
[0005] Devices for generating haptic feedback are known from WO 2017 / 060011 A1, WO 2018 / 046201 A1 and WO 2022 / 248244 A1, in which a reinforcing element for stroke amplification is attached to a piezoelectric actuator. The reinforcing element is in each case in the form of a metal sheet. According to WO 2022 / 248244 A1, excessive deformation of the reinforcing element when too great a force is applied is prevented by a mechanical stop. The mechanical stop is formed by deep drawing a central region of the reinforcing element or by fastening an additional element to an inner side of the reinforcing element. The object of the present invention is to provide a haptic component with improved properties.
[0006] According to a first aspect, a haptic component has a piezoelectric actuator and at least one reinforcing element with a lateral edge region, in which the reinforcing element is fastened to the piezoelectric actuator, and with a central region which is movable perpendicular to a main surface of the actuator. A stop structure for stopping against the actuator is formed in the central region. The central region also has a non-stop structure which is not formed for stopping against the actuator. The stop structure has at least two stop regions, between which a non-stop region of the non-stop structure is arranged. In particular, this arrangement of stop regions and non-stop region can be seen in a cross-section of the haptic component perpendicular to a main surface of the actuator.
[0007] Structuring a stop in this way can, on the one hand, increase the stability of the reinforcing element, compared to a stop that is merely designed as a homogeneous circular surface, which may also have a hole inside for pressure equalization. Furthermore, the stop structure can achieve a more uniform force application to the actuator when the stop structure is in contact with the actuator, so that the force is not concentrated in a small area.
[0008] It has been found that excessive
[0009] When force is applied, deformation of the reinforcement element can occur in such a way that a force is exerted on the actuator mainly at the edge areas of the stop. Furthermore, excessive deformation can lead to damage to the reinforcement element. By structuring the reinforcement element, the total area of the edge areas, i.e. those stop areas that border on non-stop areas, can be increased. This can prevent damage to the actuator and the reinforcement element even at higher forces.
[0010] The actuator can be arranged between the reinforcement element and another reinforcement element. The reinforcement elements can be of similar design, in particular, they can have similar stop structures.
[0011] The actuator is designed, for example, as a piezoceramic actuator. The stop structure prevents the piezoceramic from breaking under excessive force. For example, the actuator has a square basic shape. This basic shape corresponds to one of the main surfaces of the actuator. The actuator can also have an elongated rectangular basic shape, for example.
[0012] The reinforcing element has, for example, a circular basic shape. It is also possible for the reinforcing element to have a rectangular basic shape. The reinforcing element can be formed from a sheet metal. The sheet metal has, for example, the shape of a basin or a truncated cone.
[0013] The stop structure can be formed integrally with the non-stop structure. In particular, the stop structure is an integral component of other regions of the reinforcing element, for example, also of the edge region. If the reinforcing element is formed as a sheet metal, the stop structure can be formed as a formed part of the sheet metal. For example, the stop structure is formed by deep-drawing the sheet metal. The non-stop structure is not deep-drawn.
[0014] The stop structure can have several separate partial stops, whereby the partial stops are separated by the non-stop structure.
[0015] For example, the stop structure has one or more circular rings or circular segments. The non-stop structure can also have one or more circular rings or circular segments. For example, the stop structure has a plurality of concentrically arranged circular rings. The circular rings can be arranged concentrically around a center point of the reinforcing element. One or more non-stop regions can also be designed in the form of circular rings or in the form of webs between the circular segments. The stop regions can also be designed in the form of webs. For example, the webs extend from a central point towards the edge region. The circular rings or circular segments can be completely separate or connected by bridges.
[0016] For example, the stop structure may have multiple circular segments, and the non-stop structure may be formed by webs between the circular segments, or the non-stop structure may have multiple circular segments, and the stop structure may be formed by webs between the circular segments. In principle, any geometry of the stop structures is also possible for the non-stop structures, and vice versa.
[0017] For example, the stop structure and / or the non-stop structure has the shape of a cross.
[0018] The stop structure can be arranged within a circular area so that an outer edge region of the stop structure is in the form of a circular ring or interrupted circular ring.
[0019] Stop areas of the stop structure can alternate with non-stop areas from a center point of the reinforcing element towards the edge area.
[0020] The stop structure and non-stop structure can be formed only in the central region of the reinforcing element. Thus, the structure can be formed such that it does not extend into the edge region. It is also possible for the stop and non-stop structure to be formed only in an inner region of the central region.
[0021] For example, the structure extends only over half the maximum extent of the central area.
[0022] For example, the central area is circular and the stop area is arranged within a circle with half the radius.
[0023] Alternatively or additionally, stop regions and non-stop regions can alternate along a circular line around a center point of the reinforcing element. According to a further aspect, a method for producing a haptic component is specified. It can, in particular, be the haptic component described above. In the method, a sheet metal is provided for forming the reinforcing element. The sheet metal is plastically deformed, and the stop structure is formed in the process.
[0024] For example, the sheet metal is deformed by deep drawing. Then, the sheet metal is attached to a piezoelectric actuator at its edge.
[0025] The present invention comprises several aspects , in particular devices and methods . The features , properties and
[0026] The same implementation forms should also apply to the other aspect.
[0027] Furthermore, the description of the objects specified here is not limited to the specific embodiments. Rather, the features of the individual embodiments can be combined with one another—where technically feasible.
[0028] In the following, the objects described here are explained in more detail using schematic examples.
[0029] It shows :
[0030] Figure 1A shows an embodiment of a haptic component in perspective view,
[0031] Figure 1B shows the embodiment of Figure 1A in cross section,
[0032] Figure 2A shows a further embodiment of a haptic component in perspective view, Figure 2B shows the embodiment of Figure 2A in cross section,
[0033] Figure 3 shows the embodiment of the haptic component of Figures 2A and 2B with electrical contact,
[0034] Figure 4 shows a further embodiment of a reinforcing element of a haptic component in a perspective view.
[0035] Preferably, in the following figures, the same reference numerals refer to functionally or structurally corresponding parts of the various embodiments.
[0036] Figures 1A and 1B show an embodiment of a haptic component 1 in perspective view and in cross-section. The haptic component 1 can be used, for example, in an input and / or output device, such as a touchpad or a control button.
[0037] The haptic component 1 has a piezoelectric actuator 2. This can be a piezoceramic element. In particular, it can be a ceramic multilayer component. The actuator 2 has electrical contact areas 10 for electrical contacting. The contact areas 10 are connected, for example, to electrode layers of different polarity.
[0038] The polarity is indicated by a marking, for example the point shown here on one of the contact areas 10. The actuator 2 in the present case has a square basic shape. However, other basic shapes, e.g. an elongated rectangular basic shape, are also conceivable. The haptic component 1 has a reinforcing element 3. In particular, the piezoelectric actuator 2 is arranged between the reinforcing element 3 and a further reinforcing element 4. The reinforcing elements 3, 4 are each fastened to the actuator 2 in their lateral edge regions 5. For example, the reinforcing elements 3, 4 are glued there to the actuator 2. The reinforcing element 3 can be connected to a touch surface for the input or output of haptic signals. The further reinforcing element 4 can be arranged on an abutment.
[0039] The reinforcing element 3 has a basic shape in the form of a circular surface. However, other basic shapes, such as a square basic shape, are also possible. The basic shape of the reinforcing element 3 can, in particular, correspond to the basic shape of the actuator 2.
[0040] The actuator 2 is designed to deform upon application of an electrical voltage, in particular in a plane of its main surface. Due to their attachment to the actuator 2, the reinforcing elements 3, 4 deform in such a way that a central region 6 is moved perpendicular to the surface of the actuator 2. In particular, a vibration can be generated, thus producing vibrotactile feedback.
[0041] The haptic component 1 can alternatively or additionally be designed such that the actuator 2 generates an electrical signal when a force acts on the reinforcing elements 3, 4. Haptic feedback can then be generated again. In particular, when an external compression force acts on the central regions 6 of the reinforcing elements 3, 4, an electrical signal is generated at the contact regions 10. In this way, an external haptic influence can be detected, and the haptic component 1 functions as a sensor.
[0042] The reinforcing elements 3, 4 are designed in the form of sheet metal, in particular metallic sheet metal. For example, the sheet metal comprises titanium as its material. The sheets are shaped such that the central region 6, in the rest state, stands out from the surface of the actuator 2. In particular, the reinforcing elements 3, 4 have the geometry of a basin or a truncated cone.
[0043] If excessive external force is applied to the reinforcement element(s) 3, 4, there is a risk of damage to the reinforcement elements 3, 4 and / or the piezoelectric actuator 2 and thus of failure of the haptic component 1.
[0044] The formation of a stop structure 7 is intended to limit excessive deformation of the reinforcing element 3, 4 and to distribute the mechanical load over a sufficiently large surface area of the actuator 2. The stop structure 7 is described below with reference to the reinforcing element 3. The additional reinforcing element 4 can be designed accordingly.
[0045] In the exemplary embodiments shown, the stop structure 7 is an integral part of the reinforcing element 3, in particular formed integrally with a non-stop structure 12 and the edge region 5. This enables a particularly simple manufacture of the stop structure 7. For example, the stop structure 7 is formed by a plastic deformation of the
[0046] Reinforcing element 3 is formed, such as deep drawing.
[0047] The stop structure 7 has a structure to distribute the forces more evenly across the actuator 2. In particular, the stop structure 7 is not merely designed in the form of a single circular depression, in which only one circular edge region is formed as an outer non-stop region 16. Rather, a plurality of non-stop regions 8a, 8b, 8c, 8d are formed between stop regions 7a, 7b, 7c, 7d.
[0048] Thus, edge regions 14a, 14b, 14c, 14d are located at different distances from a center point 9 of the reinforcement element. The edge region 14a is part of the outer edge of the stop structure 7. The outer edge is circular.
[0049] In this case, a hole 13 is located around the center point 9 to allow pressure equalization. Non-stop areas 8b, 8c are formed directly adjacent to the hole 13. The hole 13 is not a non-stop area because it contains no material.
[0050] It has been found that a simple, flat stop which is formed integrally with the reinforcement area can cause deformation of the reinforcement element 3 when a high force is applied, which leads to excessive force being applied to the edge areas of the stop. The force is therefore concentrated on an edge area of the stop and is not distributed evenly over the actuator 2. This can also lead to damage, in particular breakage, of the actuator 2 and to undesirable permanent deformation of the reinforcement element 3. By forming a plurality of edge areas 14a, 14b, 14c, 14d at different distances from a center point 9, the number of contact points is increased and the force is thus distributed more evenly.
[0051] In the stop structure 7 shown, several stop areas 7a, 7b, 7c, 7d alternate with non-stop areas 8a, 8b, 8c, 8d as seen from the center point 9 of the reinforcing element 3 in the direction of the edge area 5.
[0052] In the embodiment shown here, the stop regions 7a-7d form several separate partial stops 11a, 11b in the form of concentric circular rings. The circular rings are separated from one another by a non-stop structure 12 comprising several concentric circular rings.
[0053] The stop structure 7 is rotationally symmetrical about an axis through the center 9 perpendicular to a main surface of the actuator 2.
[0054] In particular, such embodiments can be suitable for a force greater than 300 N, for example up to 400 N, without causing damage to the reinforcing elements 3, 4 or the actuator 2. The maximum compression force, which is evenly distributed over the surface of the actuator, can be limited, for example, to 20 N.
[0055] Figures 2A and 2B show a further embodiment of a haptic component 1 in perspective view and in cross-section. The haptic component 1 shown here differs from the haptic component 1 of Figures 1A and 1B in the geometry of the stop structure 7.
[0056] The stop structure 7 has a plurality of separate, circular-segment-shaped partial stops 11a, 11b, 11c, 11d. Between the partial stops 11a-11d, a non-stop structure 12 having a plurality of webs is formed. The non-stop structure 12 is formed overall in the shape of a cross.
[0057] Thus, as can be clearly seen in the sectional view in Figure 2B, edge regions 14a, 14b of stop regions 7a, 7b and non-stop regions 8a, 8b, 16 are arranged at different distances from the center point 9. Overall, the surface area of the edge regions 14a, 14b is larger than with a uniformly circular structure of a stop. Thus, the force can be distributed more evenly across the actuator 2.
[0058] In the reinforcement structure shown here, stop areas 7a, 7b, 7c, 7d alternate with non-stop areas 8a, 8b, 8c, 8d along a circular line around the center point 9 of the reinforcement element 3.
[0059] The cross-shaped non-stop structure 12 shown here results in particularly good stability of the reinforcement element 3 and a particularly good distribution of the applied force. Here, too, it has been shown that a force of 400 N does not cause any damage.
[0060] The stop structure 7 shown here is non-rotationally symmetrical. The stop structure 7 is axially symmetrical with respect to a plane perpendicular to a main surface of the actuator 2.
[0061] In the present case, the stop structure 7 has four partial stops l la- l ld in the shape of a circular segment. It is also possible to provide more or fewer partial stops l la- l ld in the shape of a circular segment, for example, three or five partial stops.
[0062] The additional reinforcement element 4 can be oriented like the reinforcement element 3 or rotated relative to the reinforcement element 3 about an axis perpendicular to a main surface of the actuator 2. For example, the additional reinforcement element 4 is rotated by 45°. This can further improve the stability of the reinforcement elements 3, 4 and the uniformity of the force application.
[0063] When structuring the stop structure 7, it is advantageous if a sufficient area is available on a side facing away from the actuator 2 for fastening to the rear of a touch surface, such as a control button or a touchpad. The non-stop structure 12 between the partial stops 11a-11d also enables fastening or mounting in the region of the center point 9 of the reinforcing element 3.
[0064] For example, the non-stop structure 12 can be attached to a movable element of the contact surface by adhesive or adhesive tape. In the embodiment of Figures 1A, 1B, the annular non-stop structure 12 also forms a fastening or mounting option for system integration. The stop structure 7 and the non-stop structure 12 are only formed in the central region 6. The stop structure 7 and non-stop structure 12 are in particular only formed in an inner region of the central region 6. For example, the stop structure 7 and non-stop structure 12 lie within a circle with a radius that is less than or equal to half the radius of the central region 6.
[0065] Figure 3 shows the haptic component 1 from Figures 2A and 2B with an electrical contact 11. The electrical contact 15 establishes electrical contact with the contact areas 10. For example, the contact 15 is connected to the contact areas 10 by an electrically conductive adhesive.
[0066] By arranging contact areas 10 of different polarity only on one side of the actuator 2, simple electrical contact is possible using various methods, for example flexible contacts and cables.
[0067] Figure 4 shows a further embodiment of a reinforcing element 3, 4 of a haptic component 1 in a perspective view. The haptic component 1 can be designed as in the further embodiments.
[0068] The reinforcement element 3 has an integral stop structure 7, which is circular in shape. The stop structure 7 surrounds a non-stop structure 12, which is also circular in shape. The non-stop structure 12 surrounds a hole 13 in the reinforcement element 3. The non-stop structure 12 can be used for attachment to a user interface, as in the other embodiments.
[0069] Here too, the stop structure 7 has several edge areas 14a, 14b, so that the force on the actuator 2 can be distributed more evenly than would be possible with only one edge area.
[0070] In all embodiments shown, the stop structure 7 is formed as an integral component of the reinforcing element 3. In particular, the stop structure 7 is introduced by deforming the reinforcing element 3. It is also possible to form the stop structure 7 by attaching a separate element, for example, a plastic film or a foam. For example, it can be a Kapton film.
[0071] Furthermore, it is also possible for the haptic component 1 to have a separate element in addition to an integrated stop structure 7 in order to further homogenize the force effect.
[0072] Reference sign
[0073] 1 haptic component
[0074] 2 Actuator 3 Reinforcing element
[0075] 4 additional reinforcement element
[0076] 5 Marginal area
[0077] 6 Central area
[0078] 7 Stop structure 7a-7d Stop areas
[0079] 8a- 8d Non-stop areas
[0080] 9 Center
[0081] 10 electrical contact area
[0082] 11a, 11b, 11c, l ld Partial stops 12 Non-stop structure
[0083] 13 holes
[0084] 14a, 14b, 14c, 14d edge area
[0085] 15 electrical contact
[0086] 16 outer non-stop area
Claims
Patent claims 1. Haptic component (1) comprising a piezoelectric actuator (2), at least one reinforcing element (3, 4) with a lateral edge region (5) in which the reinforcing element (3, 4) is fastened to the piezoelectric actuator (2), and with a central region (6) which is movable perpendicular to a main surface of the actuator (2), wherein the reinforcing element (3, 4) in the central region (6) has a stop structure (7) for stopping against the actuator (2) and at least one non-stop structure (12) which is not designed for stopping against the actuator (2), wherein the stop structure (7) has at least two stop regions (7a, 7b, 7c, 7d) and the non-stop structure (12) has at least one non-stop region (8a, 8b, 8c, 8d), wherein the non-stop region is between the two is arranged in stop areas.
2. Haptic component according to claim 1, wherein the stop structure (7) is formed integrally with the non-stop structure (12).
3. Haptic component according to one of the preceding claims, wherein the stop structure (7) has a plurality of separate partial stops (11a, 11b, 11c, 11d) which are separated by the non-stop structure (12).
4. Haptic component according to one of the preceding claims, in which the stop structure (7) has a plurality of partial stops (11a, 11b, 11c, 11d) in the form of circular rings or circular segments.
5. Haptic component according to claim 4, wherein the partial stops (11a, 11b, 11c, 11d) are designed in the form of concentric circular rings.
6. Haptic component according to one of the preceding claims, in which the stop structure (7) is arranged within a circular area, so that an edge region (14a, 14b) of the stop structure (7) runs in the form of a circular ring or interrupted circular ring.
7. Haptic component according to one of the preceding claims, in which the stop structure (7) has a plurality of stop regions (7a, 7b, 7c, 7d) which engage with non- Stop areas (8a, 8b, 8c, 8d) alternate from a center point (9) of the reinforcing element (3) in the direction of the edge area (5).
8. Haptic component according to one of the preceding claims, wherein along a circular line around a center point (9) of the reinforcing element (3, 4) alternating stop areas (7a, 7b, 7c, 7d) and non-stop areas (8a, 8b, 8c, 8d) are arranged.
9. Haptic component according to one of the preceding claims, in which the stop regions (7a, 7b, 7c, 7d) and / or the non-stop regions (8a, 8b, 8c, 8d) are designed in the form of a plurality of webs.
10. Haptic component according to claim 9, wherein the webs extend from a center point (13) of the reinforcing element (3, 4) in the direction of the edge region (5).
11. Haptic component according to one of the preceding claims, in which the stop structure (7) has a plurality of circular segments and the non-stop structure (12) is designed in the form of webs between the circular segments or in which the non-stop structure (12) has a plurality of circular segments and the stop structure (7) is designed in the form of webs between the circular segments.
12. Haptic component according to one of the preceding claims, wherein the stop structure (7) and / or the non-stop structure (12) has the shape of a cross.
13. Haptic component according to one of the preceding claims, wherein the actuator (2) has a square basic shape and the reinforcing element (3, 4) has a circular basic shape.
14. Haptic component according to one of the preceding claims, wherein the reinforcing element (3, 4) has a hole (13), wherein the non-stop structure (12) is directly adjacent to the hole (13).
15. Haptic component according to one of the preceding claims, in which the stop structure (7) is formed only in the central region of the reinforcing element (3, 4).
16. A method for producing the haptic component (1) according to one of the preceding claims, comprising the steps: A) Providing a sheet for forming the reinforcing element (3, 4), B) Plastic deformation of the sheet to form the stop structure (7), C) Fastening the sheet metal in its edge area (5) to a piezoelectric actuator (2).
17. The method according to claim 16, wherein the plastic deformation comprises deep drawing of the sheet metal.