Input device with improved spring elements for movable mounting of the control unit, associated spring element and assembly procedure

Description

[0001] The invention relates to an input device with an operating part, which for example has a touch-sensitive input surface, wherein the operating part is mounted so as to be movable relative to a support and elastically returnable to a rest position in order to be able to be set into vibration or at least movement by means of an actuator. The vibration or movement is perceptible to the operator upon contact and thus serves to generate haptic feedback during input. Such a procedure is known from the prior art. For this vibration, different vibration directions are proposed in the prior art, for example in US 2008055277 A1. Different concepts are also known with regard to the actuator, preferably the electrically operated actuator, for example those with electromagnetic, piezoelectric, capacitive or electrostatic drives for exciting movement or vibration.The present invention addresses the problem of a "floating" and restoring mounting of the control element. Here, a mounting that is as friction-free, low-wear, and vandalism-resistant as possible is essential to reliably maintain the rest position of the control element. Particularly in motor vehicles, it is also important to save space and weight. Furthermore, achieving a predetermined and stress-free installation position is crucial for ensuring that the haptic feedback is set as specified and reproducible. High demands are placed on the mounting when the direction of the movement or vibration excitation caused by the actuator does not coincide with the direction of the actuating force applied upon contact, especially when both directions are orthogonal to each other.Even the slightest deformation of the spring elements that determine the oscillating bearing and the return spring significantly disrupt the haptic feedback and prevent it from occurring as intended. Such deformations can be caused, for example, by incorrect handling during the assembly process.

[0002] Therefore, there is a need for a control unit mounting system that reliably and, above all, reproducibly establishes and maintains a restoring positional change parallel to the touch-sensitive input surface of the control unit after installation, thus eliminating the need for complex adjustment work. Furthermore, the restoring effect must be permanent and consistent to avoid the need to readjust the vibration excitation by the actuator during operation.

[0003] An input device according to the preamble of the independent claims is known from EP 3 499 343 A2. Design features of input devices of this type are known from US 2020 / 083790 A1, JP 6 591617 B2, WO 2014 / 096565 A1, and US 2018 / 260027 A1.

[0004] Against this background, the object of the present invention is to provide an input device with improved bearings, in particular one whose assembly and adjustment effort is minimized. This object is achieved by an input device according to claim 1. A correspondingly advantageous assembly method is the subject of the independent claim. Advantageous embodiments are the subject of the respective dependent claims. It should be noted that the features individually listed in the patent claims can be combined with one another in any technologically expedient manner and demonstrate further embodiments of the invention. The description, particularly in conjunction with the figures, further characterizes and specifies the invention.

[0005] The invention relates to an input device. The input device according to the invention has an operating element, in particular a touchpad or a touchscreen. The operating element has an input surface, in particular a touch-sensitive input surface. The term "touchpad" within the meaning of the invention is to be interpreted broadly and refers to any touch-sensitive input device in which a touch of an input surface is detected with spatial resolution, but regardless of the degree of spatial resolution. A touchpad is preferably provided to effect an input, for example, the control of a cursor on a display, according to a touch path.

[0006] According to the invention, the touchpad can be part of a combination of a display and a touch-sensitive input surface ("touchscreen"), or it can define a display-free, purely touch-sensitive input surface. The touch coordinates and their paths are determined, for example, capacitively, resistively, or optically.

[0007] The input device according to the invention further comprises a support on which the operating element, or touchpad, is movably mounted. The input device according to the invention further comprises means for restoring the operating element to the support, which are designed to deflect the operating element from a rest position in a deflection direction substantially parallel to the input surface and to elastically return it to the rest position. In other words, a movement of the operating element from or preferably around the rest position is enabled.

[0008] According to the invention, an actuator is further provided for initiating movement of the operating part in the deflection direction and thus for generating haptic feedback in said deflection direction. This is preferably an electrically actuated actuator, for example one with an electromagnetic, piezoelectric, capacitive, or electrostatic drive for initiating movement or vibration. For example, an electromagnetic actuator is provided that comprises an armature and an electric coil that interacts electromagnetically with the armature. The actuator is preferably attached exclusively to the operating part.

[0009] According to one embodiment, a force sensor, for example a piezoelectric, capacitive, or inductive force sensor, preferably an optical force sensor, is provided to detect an actuation force acting on the input surface. For example, if a predetermined actuation force is exceeded, haptic feedback generated by the actuator is triggered. For example, the force sensor is arranged between the support and the operating element or between the support and a housing on which the support is elastically or movably mounted.

[0010] According to the invention, the means for restoring the mounting of the operating part comprise two spring elements extending substantially parallel to one another and substantially parallel to the input surface, each having at least one leaf spring strip made of spring steel and at least three fastening elements distributed along the leaf spring strip, in which the leaf spring strip is positively received. The two outer fastening elements are arranged at an equal distance from the one nearest adjacent inner fastening element, so that between the outer fastening elements and the nearest adjacent inner fastening element of the same spring element, oscillatable leaf spring strip sections of substantially the same length remain in a plane substantially parallel to the input surface. The leaf spring strip is preferably arranged upright between the operating part and the support, i.e.the main surface of the leaf spring strips is arranged essentially orthogonally to the input surface.

[0011] According to the invention, the outer fastening elements of a first spring element of the two spring elements and an inner fastening element of a remaining second spring element of the two spring elements form the operating element-side fastening elements, which is intended to express that they are each fastened to the operating element. According to the invention, the outer fastening elements of the second spring element and an inner fastening element of the first spring element form the carrier-side fastening elements and are thus each fastened to the carrier. The fastening elements are fastened, for example, to the operating element or to the carrier in a force-fitting, material-fitting, and / or form-fitting manner.

[0012] Preferably, all fastening elements are made of a thermoplastic; more preferably, at least one of the fastening elements is at least partially made of a thermoplastic elastomer. The latter causes the otherwise rigid structure of the operating element to yield in a defined manner under the action of an operating force, thus enabling the actuation force to be measured by the force sensor described above.

[0013] The leaf spring strips are manufactured, for example, in a single stamping step and are preferably of identical design. The leaf spring strip section remaining between the outer fastening element and the next adjacent inner fastening element, and preferably freely accessible, is capable of elastic vibration and functions as a "bending beam." An opening in the leaf spring strip section can be provided to adjust the elastic compliance. The main surfaces of the leaf spring sections are oriented essentially perpendicular to the input surface and exhibit the highest compliance in the direction perpendicular to the input surface, corresponding to the deflection direction. In comparison, they exhibit high rigidity under compressive and tensile stress in the longitudinal direction and in the direction perpendicular to the input surface.

[0014] The input device designed according to the invention saves space and weight thanks to the design of the mounting means. Furthermore, the risk of damage or deformation of the spring elements is virtually eliminated. The return behavior is reproducible even without adjustment effort. The three-point mounting provided according to the invention, both by the support-side fastening elements to the support and by the control-side fastening elements to the control unit, ensures a reproducible and well-defined movement and vibration behavior of the control unit.

[0015] Preferably, at least the fastening elements on the control panel side are integrally connected to the control panel, preferably welded. For example, at least one fastening element and / or the associated contact surface has one or more energy directors, such as a wedge-shaped protrusion, prior to the attachment to the support or control panel, in order to be integrally connected to the support or control panel by ultrasonic welding. Additionally, means for clamping the fastening element to the support or control panel can be provided.

[0016] Preferably, at least the fastening elements on the support side are designed to create a snap-in connection with the support in order to simplify assembly.

[0017] Preferably, the carrier-side fastening elements are each provided with an assembly aid, wherein the assembly aid preferably projects beyond the carrier on its side facing away from the operating part, for example at least at the beginning of the assembly process. For example, the assembly aid is designed as a protruding gripping aid for manual or mechanical assembly. For example, the fastening element in question forms a rod extending orthogonally away from the leaf spring strip as an assembly aid. For example, the assembly aid is provided to hold the fastening element in contact with the carrier and / or to lock the fastening element to the carrier. Preferably, the assembly aid and the remaining portion of the fastening element are formed as a single piece.

[0018] According to a preferred embodiment, a predetermined breaking point is provided for separating the mounting aid from a remainder of the carrier-side fastening element remaining on the input device. For example, the predetermined breaking point is provided at the transition between the rod-shaped mounting aid and the remaining remainder of the fastening element and is designed as a weakening of the material thickness, in particular as a tapered portion.

[0019] Preferably, the carrier-side fastening elements are arranged in a first plane and the operating part-side fastening elements are arranged in a second plane parallel to the first plane or all in a common plane.

[0020] Preferably, the fastening elements are fixed to the leaf spring strip by overmolding the leaf spring strip.

[0021] The invention further relates to a method for producing an input device comprising the following steps. In a provision step, an operating element with an input surface is provided. In a further provision step, a support is provided. Furthermore, means are provided for restoring the operating element to the support, wherein the means are configured to support the operating element in a deflection direction substantially parallel to the input surface, deflectable from a rest position, and elastically restoring it.These means for restoring the operating element comprise two spring elements, each comprising a leaf spring strip made of spring steel and two outer fastening elements and at least one inner fastening element, in which the leaf spring strip is positively received and which are arranged distributed along the leaf spring strip, wherein the outer fastening elements are evenly spaced from a next adjacent inner fastening element. The spring elements are produced, for example, in a preceding thermally forming process step by overmolding with a thermoplastic. Preferably, at least one fastening element is formed entirely or at least partially from a thermoplastic elastomer.

[0022] In a fastening step, an actuator is attached to the support and / or the control unit to stimulate movement of the control unit in the deflection direction, in order to generate haptic feedback for an operator via the actuator. Preferably, the actuator is attached exclusively to the control unit.

[0023] In a further fastening step, which can be arranged before or after the fastening of the actuator, the outer fastening elements of a first spring element of the two spring elements and a middle fastening element of a remaining second spring element of the two spring elements are each fastened to the operating part, whereby these form the fastening elements on the operating part.

[0024] In a further fastening step, which can be arranged before, between or after the aforementioned fastening steps, the outer fastening elements of the second spring element and an inner fastening element of the first spring element are each fastened to the carrier, said fastening elements forming the fastening elements on the operating part, so that between the outer fastening elements and the next adjacent inner fastening elements of the same spring element, oscillatable leaf spring strip sections of substantially the same length remain in a common plane substantially parallel to the input surface.

[0025] Preferably, the fastening elements on the control panel are secured to the control panel by ultrasonic welding. According to a preferred embodiment, at least one fastening element provided and / or the associated contact surface on the provided support or control panel has an energy director, such as a wedge-shaped protrusion, for bonding to the control panel by ultrasonic welding.

[0026] Preferably, the support-side fastening elements are secured to the support by establishing a force-locking and / or positive-locking connection, with this fastening step following the fastening of the control panel-side fastening elements. For example, the fastening element is brought into contact with the support and only secured in a form-locking and / or force-locking manner by adjusting a holding device to prevent damage due to overloading of the spring element.

[0027] Preferably, the carrier-side fastening elements each have a mounting aid, wherein the fastening of the carrier-side fastening elements takes place by means of or using the respectively provided mounting aid, wherein more preferably the mounting aid projects beyond the carrier on its side facing away from the operating part.

[0028] Preferably, the assembly aids are separated from the remainder of the carrier-side fastening element remaining on the input device at a predetermined breaking point after the carrier-side fastening elements have been fastened.

[0029] The invention and the technical environment are explained in more detail below with reference to the figures. It should be noted that the figures show a particularly preferred embodiment of the invention, but are not limited thereto. They schematically show: Figure 1 shows a schematic sectional view through an embodiment of the input device 1 according to the invention; Figure 2 shows a perspective view of a first spring element 4a belonging to the input device 1; Figure 3 shows a perspective view of a second spring element 4a belonging to the input device 1; Figure 4 shows a perspective rear view of the carrier 2 from Figure 1 ; Figure 5 a perspective rear view of the control unit 2 from Figure 1 .

[0030] Figure 1 shows an embodiment of the input device 1 according to the invention. The input device according to the invention has an operating part 2, for example a touchpad or a touchscreen. The operating part 2 has an input surface 10, in particular a touch-sensitive input surface.

[0031] The input device 1 according to the invention further comprises a support 3 on which the operating part 2 is movably mounted. The input device 1 according to the invention further comprises means 4 for restoring the operating part 2 to the support 3, which means are designed to deflect the operating part 2 from a rest position in a deflection direction S substantially parallel to the input surface and to elastically return it to the rest position. In other words, a movement of the operating part 2 from or preferably around the rest position is enabled.

[0032] Furthermore, an actuator 13 is provided for stimulating movement of the operating part 2 in the deflection direction S and thus for generating haptic feedback in said deflection direction S. Preferably, this is an electrically actuated actuator 13, such as a voice coil actuator, which is attached exclusively to the actuating part.

[0033] According to one embodiment, a force sensor 12, for example an optical force sensor, is provided to detect an actuation force F acting on the input surface 10. For example, if a predetermined actuation force F is exceeded, haptic feedback generated by the actuator 13 is triggered. Here, the force sensor 12 is arranged between the carrier and a housing on which the carrier is elastically or movably mounted.

[0034] Here, the means 4 for restoring the operating part comprise two spring elements 4a, 4b extending substantially parallel to one another and substantially parallel to the input surface 10, each having at least one leaf spring strip 5a, 5b made of spring steel and three fastening elements 6a, 7a; 6b, 7b in which the leaf spring strip 5a, 5b is positively received. Here, the fastening elements 6a, 7a; 6b, 7b, formed from a thermoplastic, are fixed to the leaf spring strip 5a, 5b by overmolding the leaf spring strip 5a, 5b in a thermally forming process.

[0035] The fastening elements 6a, 7a; 6b, 7b of a spring element 4a, 4b are arranged at equal distances from one another along the leaf spring strip 5a, 5b, so that between the fastening elements 6a, 7a; 6b, 7b of the same spring element 4a, 4b, several leaf spring strip sections of substantially the same length remain, capable of oscillation in a plane substantially parallel to the input surface. In the embodiment shown, the leaf spring strip 5a, 5b is arranged upright between the operating part 2 and the support 3, i.e., the main surface of the leaf spring strip 5a, 5b is arranged substantially orthogonal to the input surface 10.

[0036] As in the Figure 2 and 3 is shown, the outer fastening elements 7a of a first spring element 4a, which in Figure 2 and an inner fastening element 6b of a second spring element 4b, which is shown in Figure 3is shown, the control panel-side fastening elements 7a, 6b, which is intended to express that these are each fixed to the control panel 2. Furthermore, the outer fastening elements 7b of the second spring element 4b and an inner fastening element 6a of the first spring element 4a form the carrier-side fastening elements 7b, 6a and are thus each fixed to the carrier 3. The control panel-side fastening elements 7a, 6b are each materially bonded, here by ultrasonic welding, to the control panel 2, more precisely in the area of ​​the receptacles 17a and 16b. Figure 5For this purpose, the associated contact surface of the operating part 2 has at least one energy director, such as a wedge-shaped elevation, in order to be integrally connected to the operating part 2 by ultrasonic welding. In addition, means for clamping the operating part-side fastening element 7a, 6b to the operating part 2 can be provided. In the embodiment shown, the carrier-side fastening elements 7b, 6a and the operating part-side fastening elements 6a, 7b are arranged in a common plane that is essentially parallel to the input surface 10.

[0037] While the carrier-side fastening elements 7b, 6a are fixed by positive and / or force-fitting mounting on the carrier 3 in the associated mountings 16a and 17b, the latter being in Figure 4can be seen. The positive or non-positive reception is achieved by adjusting a holding device 20, which is realized here by a screw guided in a conical threaded hole, wherein the screwing of the screw into the threaded hole causes the production of the positive and / or non-positive connection between the carrier 3 and the carrier-side fastening element 6a, as shown in Figure 1 is shown.

[0038] The leaf spring strips 5a, 5b are each manufactured in a single stamping step, for example, and are preferably identically designed. The leaf spring strip section remaining between the inner fastening element 6a, 6b and the outer fastening elements 7a, 7b, and preferably freely accessible, is elastically oscillatable and functions as a "bending beam." An opening in the leaf spring strip section can be provided, as shown, to adjust the elastic compliance. Their main surfaces are oriented essentially perpendicular to the input surface 10 and exhibit the highest compliance in the direction perpendicular to the input surface 10, corresponding to the deflection direction S. In comparison, they exhibit high rigidity under compressive and tensile stress in the longitudinal direction and in the direction perpendicular to the input surface 10.

[0039] The input device 1 designed according to the invention saves space and weight thanks to the specific configuration of the mounting means 4. Furthermore, the risk of damage or deformation of the associated spring elements 4a, 4b is virtually eliminated. The return behavior is reproducible even without adjustment effort. The three-point mounting provided according to the invention, both by the support-side fastening elements 7b, 6a towards the support 3 and by the control-panel-side fastening elements 7a, 6b towards the control panel 2, ensures a reproducible and well-defined movement and vibration behavior of the control panel 2.

[0040] To facilitate assembly, the carrier-side fastening elements 7b, 6a are each provided with an assembly aid 9a, 9b, wherein the assembly aid 9a, 9b protrudes beyond the carrier 3 on its side facing away from the operating part 2 and is designed as a protruding gripping aid for manual or mechanical assembly. More precisely, the fastening element in question forms a rod extending orthogonally away from the leaf spring strip 5a, 6b as an assembly aid. Here, the assembly aid 9a, 9b is intended to lock the carrier-side fastening element 7b, 6a to the carrier 3. Here, the assembly aid 9a, 9b and the remaining portion of the carrier-side fastening element 7b, 6a are formed as a single piece.

[0041] A predetermined breaking point 8a, 8b is provided for separating the mounting aid 9a, 9b from a remnant of the support-side fastening element 7b, 6a remaining on the input device 1. More precisely, the predetermined breaking point 8a, 8b is provided at the transition between the rod-shaped mounting aid 9a, 9b and the remaining remnant of the support-side fastening element 7b, 6a and is designed as a weakening of the material thickness, in particular as a taper. Therefore, it is possible to separate the mounting aids 9a, 9b from the remnant of the support-side fastening element 7b, 6a remaining on the input device 1 after the support-side fastening elements 7b, 6a have been attached at the predetermined breaking point 8a, 8b.

Claims

1. Input device (1), comprising: an operating element (2) with an input surface (10); a carrier (3); means (4) for mounting the operating element (2) in a restoring manner on the carrier (3), which are designed to mount the operating element (2) such that it can be deflected from a rest position in a direction of deflection (s) substantially parallel to the input surface (10) and elastically restoring it into the rest position; and an actuator (13) for excitation of movement of the operating element (2) in the direction of deflection (S) in order to generate haptic feedback for an operator; wherein the means (4) for mounting the operating element (2) in a restoring manner comprise two spring elements (4a, 4b) extending substantially parallel to each other and substantially parallel to the input surface, each comprising a leaf spring strip (5a, 5b) made from spring steel and at least three fastening elements (6a, 7a; 6b, 7b) which are arranged along the associated leaf spring strip and in which the leaf spring strip (5a, 5b) is received in a positively locking manner, with the result that swinging leaf spring strip portions of substantially the same length each remain between the outer fastening elements (7a; 7b) and the nearest, inner fastening elements (6a, 6b) of the same spring element (5a, 5b) in a plane substantially parallel to the input surface (10); characterized in that the outer fastening elements (7a) of a first spring element (5a) of the two spring elements (5a, 5b) and an inner fastening element (6b) of a remaining second spring element (5b) of the two spring elements (5a, 5b) form the operating element-side fastening elements (7a, 6b) and are each fixed on the operating element (2), and the outer fastening elements (7b) of the second spring element (5a) and an inner fastening element (6a) of the first spring element (5a) form the carrier-side fastening elements (6a, 7b) and are each fixed on the carrier (3).

2. Input device (1) according to Claim 1, wherein the operating element-side fastening elements (7a, 6b) are connected in an integrally joined manner, preferably welded, to the operating element (2).

3. Input device (1) according to either of the preceding claims, wherein the carrier-side fastening elements (6a, 7b) are configured to establish a latching connection to the carrier (3).

4. Input device (1) according to one of the preceding claims, wherein the carrier-side fastening elements (6a, 7b) each have a mounting aid (9a, 9b), wherein the mounting aid (9a, 9b) preferably in each case protrudes beyond the carrier (3) on its side facing away from the operating element (2).

5. Input device (1) according to the preceding claim, wherein a predetermined break point (8a, 8b) is provided in each case for separating the mounting aid (9a, 9b) from a remainder of the carrier-side fastening element (6a, 7b) remaining on the input device (1).

6. Input device (1) according to one of the preceding claims, wherein the carrier-side fastening elements (6a, 7b) are arranged in a first plane, and the operating element-side fastening elements (6b, 7a) are arranged in a second plane parallel to the first plane, or the carrier-side fastening elements (6a, 7b) and the operating element-side fastening elements (6b, 7a) are arranged in a common plane.

7. Input device (1) according to one of the preceding claims, wherein the fastening elements (6a, 7a; 6b, 7b) are fixed in each case on the leaf spring strip (5a, 5b) by overmoulding the leaf spring strip (5a, 5b).

8. Input device (1) according to one of the preceding claims, wherein all fastening elements (6a, 7a; 6b, 7b) are formed from a thermoplastic, and preferably at least one of the fastening elements (6a, 7a; 6b, 7b) is at least partially formed from a thermoplastic elastomer here.

9. Method for producing an input device (1), comprising the following steps: providing an operating element (2) with an input surface (10); providing a carrier (3); providing means (4) for the mounting the operating element (2) in a restoring manner on the carrier (3), which are designed to mount the operating element (2) such that it can be deflected in a direction of deflection (s) substantially parallel to the input surface (10) from a rest position and resets elastically; wherein the means (4) for mounting the operating element (2) in a restoring manner comprise two spring elements (4a, 4b), each having a leaf spring strip (5a, 5b) made from spring steel and at least three fastening elements (6a, 7a; 6b, 7b) arranged distributed along the associated leaf spring strip (5a, 5b), in which the leaf spring strip (5a, 5b) is received in a positively locking manner, with the result that swinging leaf spring strip sections of substantially the same length remain between the outer fastening elements (7a, 7b) and the nearest inner fastening elements (6a, 6b) of the same spring element (4a, 4b) in a common plane substantially parallel to the input surface (10), and the spring elements (4a, 4b) extend substantially parallel to each other and substantially parallel to the input surface (10); fastening an actuator (13) to the operating element (2) to excite movement of the operating element (2) in the direction of deflection (S) in order to generate haptic feedback for an operator; characterized by fastening the outer fastening elements (7a) of a first spring element (4a) of the two spring elements (4a, 4b) and an inner fastening element (6b) of a remaining second spring element (4b) of the two spring elements (4a, 4b) in each case to the operating element (2), these forming the fastening elements (7a, 6b) on the operating element side; and by fastening the outer fastening elements (7b) of the second spring element (5b) and an inner fastening element (6a) of the first spring element (4a) in each case to the carrier (3), these forming the carrier-side fastening elements (7a, 6b).

10. Method according to the preceding claim, wherein the mounting elements (7a, 6b) on the operating element side are fixed by ultrasonic welding on the operating element (2).

11. Method according to either of the preceding Claims 15 or 16, wherein the carrier-side fastening elements (7b, 6a) are fixed by latching on the carrier (3).

12. Method according to one of the preceding Claims 15 to 17, wherein the carrier-side fastening elements (7b, 6a) each have an assembly aid (9a, 9b), and the fastening of the carrier-side fastening elements (7a, 6b) takes place by means of or using the respective provided mounting aid (9a, 9b), wherein the assembly aid (9a, 9b) preferably in each case protrudes beyond the carrier (3) on its side facing away from the operating element (2).

13. Method according to the preceding claim, wherein the mounting aids (9a, 9b), after fastening the carrier-side fastening elements (7a, 6b), are separated at a predetermined break point (8a, 8b) from the rest of the carrier-side fastening element (7a, 6b) remaining on the input device (1).

14. Method according to one of the preceding Claims 15 to 19, wherein all fastening elements (6a, 7a; 6b, 7b) are formed from a thermoplastic, and preferably at least one of the fastening elements (6a, 7a; 6b, 7b) is formed at least partially from a thermoplastic elastomer here.