Force-sensitive operating device for a motor vehicle

Abstract

Operating device (3) for a motor vehicle (1), comprising: - a pivoting element (20) pivotably mounted about a rotation axis (21), - a touchpad (5) with a sensor matrix (13) for spatially resolved detection of a touch of an operating object (6) on an operating side (7) of the touchpad (5), - a printed circuit board (12) with at least one force sensor (16) against which the pivoting element (20) rests and to which the pivoting element (20) at least partially transmits a contact force (9) exerted by the operating object (6) on the operating side (7), - at least one light source (28) and, for each light source (28), a respective light guide (30), which is designed to guide a light (29) from the light source (28) through the pivoting element (20) to a rear side (38) of the touchpad (5) opposite the operating side (7) and to emit the light (29) in a contactless manner to an illuminated symbol (11) provided in the touchpad (7), characterized in that the touchpad (5) is held elastically deflectably on the pivoting element (20) via a spring arrangement comprising at least one spring element (25), wherein in the spring arrangement the at least one spring element (25) comprises a leaf spring, in which a longitudinal direction, along which the leaf spring is incompressible, is oriented perpendicular to a surface plane of the operating side (7), such that a contact force (9) is to be transmitted in a direction perpendicular to the surface plane of the operating side (7) along a transmission direction (26).

Description

The invention relates to an operating device for a motor vehicle. The operating device provides a touchpad, that is to say a touch-sensitive plate, on which a touch by an operating object, for example a finger, can be detected in a spatially resolved manner by means of a sensor matrix. Furthermore, at least one force sensor is provided, by means of which the contact pressure force which the operating object exerts on the touchpad can be detected. The invention also includes a motor vehicle having an embodiment of the operating device according to the invention.An operating device of the aforementioned type is known, for example, from DE 10 2008 035 907 A1. The touchpad is then mounted on a plurality of helical springs, by means of which the touchpad can be pressed down perpendicularly to the plane of the operating surface. Between the touch pad and one of the coil springs is a force sensor that detects the force transmitted to the coil springs.DE 10 2007 018 892 A1 discloses an operating device for a motor vehicle, in which light can be emitted through openings in a touchpad. The light is guided here by means of light guides from the respective light emitting diode to the through opening in the touchpad.DE 103 04 704 A1 discloses a touchpad which is mounted on a plurality of pushbuttons in a tiltable manner. By applying a corresponding finger pressure to the touchpad, at least one of the buttons can be selectively actuated.DE 10 2011 017 383 A1 discloses a touchscreen whose user interface outputs acoustic and preferably mechanical feedback signals or feedback signals to the user.DE 11 2010 004 756 T5 discloses a touchpad with force sensors and actuator feedback, which can be installed in a laptop. A linear motor can be coupled to the touch-sensitive disk of the touchpad via a lever.DE 20 2008 001 970 U1 describes an operating device having a carrier plate on which a position-detecting element is arranged in order to be able to detect different touch points on the carrier plate. In addition, in order to receive a pressure input, the carrier plate is arranged on a pressure sensing element. Overall, this results in a tilting touch control field.WO 2011 / 110470 A2 discloses an operating device with a backlit pane, on which a touch of a finger of a user is detected by touch sensors.DE 10 2011 119 746 A1 discloses an actuating device in which a carrier element is configured as a lever arm which is mounted pivotably about an axis of rotation. A display device for displaying an operating interface is arranged on the carrier element. The carrier element rests on a pressure sensor which detects a pressure force of a finger of a user acting on the carrier element. A vibration device based on an actuator system can provide haptic feedback to the finger.US 2002 / 0149561 A1 describes a touchpad which generates haptic feedback when actuated. In addition, acoustic output can be effected. A touch surface of the touchpad is arranged in a housing of the operating device in a tiltable manner.US 214 / 0002386 A1 discloses a haptic touchpad which is coupled to a housing by means of at least one elastic element, as a result of which the touchpad can be moved along a z-axis and haptic feedback can be provided.WO 2010 / 000281 A1 describes a further touchpad which is mounted by means of at least one elastic restoring element, as a result of which the touchpad can be reset into its basic position after a movement in the printing direction has been carried out.The invention is based on the object of realizing an operating device with a touchpad and detection of operating force and luminous symbology on the touchpad with little electronic switching effort.The object is achieved by the subject matters of the independent claims. Advantageous further developments of the invention result from the features of the dependent patent claims.In the control device for a motor vehicle according to the invention, it is possible to arrange all the electrical components for processing and generating electrical signals on a single printed circuit board, with the exception of the sensor matrix of the touchpad. This makes the machine production of the circuit for the operating device particularly simple and thus inexpensive.In the described manner, the operating device has a touchpad with a sensor matrix for spatially resolved detection of a touch of an operating object on an operating side of the touchpad. The touchpad is arranged on a pivot element which is mounted pivotably about an axis of rotation. In other words, the touchpad is fastened to a pivot arm. The pivot element, in turn, i.e. for example the pivot arm, abuts against the said printed circuit board. Specifically, the printed circuit board has at least one force sensor against which the pivot element bears. In other words, the pivoting element touches the circuit board at its at least one force sensor. Since the pivoting element is pivotably mounted, the pivoting element transmits a contact pressure force, which is exerted by the operating object on the operating side, at least partially to the force sensor or the force sensors.According to the invention, the touchpad is held on the pivot element in an elastically deflectable manner via a spring arrangement. For this purpose, the spring arrangement can have at least one spring element, wherein each spring element can be, for example, a leaf spring or another metal bent part. According to the invention, in the spring arrangement, the at least one spring element has a leaf spring in which a longitudinal extension direction is oriented perpendicular to a surface plane of the operating side. Along the longitudinal extension direction, a leaf spring is incompressible or rigid. By virtue of this rigid direction being oriented perpendicular to the operating side, a pressing force of the operating object acting on the operating side can be reliably transmitted to the at least one force sensor. In contrast, the touchpad of a force effect which acts in or parallel to the surface plane of the operating side can be attenuated or compensated by the leaf spring.The touchpad can thus be deflected elastically on the pivot element or the pivot arm, that is to say pivoted back and forth on the pivot element. This allows blows or pulses acting on the touchpad to be cushioned and the operator control side to be protected from breakage as a result.If the user thus presses, for example, with the finger or another operating object, for example a pin, onto the operating side of the touchpad, this force is transmitted via the spring arrangement to the pivoting element and this is in turn pressed against the at least one force sensor on account of its pivotability about the axis of rotation.At least one light source can also be arranged on the printed circuit board, wherein each light source can be provided, for example, as a light-emitting diode (LED) or a plurality of light-emitting diodes. A light guide is provided for each light source, which light guide is designed to guide a light from the respective light source through the pivot element to a rear side of the touchpad opposite the operating side of the touchpad. Furthermore, the light of the respective light source is emitted in contactless fashion by the respective light guide to a light symbol provided in the touchpad. The luminous symbol can be realized, for example, by a transparent region in the touchpad and / or by a cutout. The circuit board on the one hand and the touchpad on the other hand are each located on one of two opposite sides of the pivot element. Both the at least one light source and the at least one force sensor can be arranged on the printed circuit board and the touchpad can nevertheless be supplied with light for its luminous symbols and also be evaluated with respect to the contact pressure force of the operating object. Since each light guide emits the light to the respective light symbol in a contactless manner, the touchpad can furthermore be freely elastically deflected on the spring arrangement without a force being transmitted to the light guide in this case.The invention has further developments, which result in additional advantages.In a further development, an electric actuator is arranged on the printed circuit board and the actuator is mechanically coupled to the touchpad via a lever element. By means of the actuator, for example a linear motor or a rotary motor, a deflection force can be exerted on the touchpad via the lever element, which deflection force is then elastically deflected thanks to the spring arrangement. The advantage results that control lines and electrical supply lines for the actuator can likewise be arranged on the printed circuit board, resulting in short line paths for operating the electrical actuator.In a development, the touchpad has a sandwich arrangement comprising a glass pane, the described sensor matrix and a carrier structure. This results in the advantage that the touchpad can be constructed so as to be light weight or low weight despite the use of glass, for example soda-lime glass, so that it opposes or has a low inertia during the deflection by the spring arrangement.In a development, the carrier structure is designed as a honeycomb structure. As a result, it is light and nevertheless flexurally rigid, as a result of which the glass pane can be of particularly thin and light design.In a development, a loudspeaker and a control device are provided on the printed circuit board. The control device is designed to actuate the loudspeaker as a function of a respective signal of the at least one force sensor. In other words, when the touchpad is actuated, when a pressing force is exerted on the operating side, the pressing force is detected by the at least one force sensor and a corresponding or correlating pressure signal or force signal is generated. The control circuit generates a control signal for the loudspeaker in dependence on the force signal, so that the loudspeaker emits sound. This has the advantage that a noise can be generated in the operating device as a function of an operating actuation. In particular, a mechanical switching noise can be simulated as a result. This results in an operating impression for the touchpad which corresponds to that of a mechanical switch.In one development, a processor device coupled to the sensor matrix is provided on the printed circuit board, which is designed to ascertain a touch point of the operating object on the operating side as a function of sensor signals of the sensor matrix. In particular, two-dimensional touch coordinates are detected. Since the processor device, for example a microcontroller, is also provided on the printed circuit board, the operating device is completely autonomous with respect to the signal evaluation and signal generation. This advantageously results in a particularly simple interface, via which the operating device can be coupled to a device of the motor vehicle which is to be operated by means of the operating device.In a development, a distance of the touchpad from the axis of rotation of the pivot element is greater than 2 cm, in particular greater than 5 cm. In this way, a contact pressure force can be reliably detected on the entire surface of the operating side by means of the at least one force sensor and a correlating force signal can be generated.Furthermore, the touchpad can be deflected along this direction by means of the actuator device, for example shaken or acted on with a pulse, as a result of which haptic feedback can be provided on the touchpad for a user.The invention also includes a motor vehicle. The motor vehicle according to the invention is characterized by an embodiment of the operating device according to the invention. The operating device can be arranged, for example, in a dashboard or a central console of the motor vehicle. The operating device can be coupled to an information / entertainment system (infotainment system), for example, and can be designed to control the infotainment system depending on a touch input of a user.The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car.An embodiment of the invention is described below. The following shows: FIG. 1 shows a schematic illustration of an embodiment of a motor vehicle according to the invention; FIG. 2 is a schematic illustration of a top view of a touchpad of an operating device that may be installed in the motor vehicle of FIG. 1 ; FIG. 3 shows a schematic illustration of a printed circuit board of the operating device; FIG. 4 shows a schematic illustration of a pivoting element and an actuator of the operating device; and FIG. 5 shows a schematic illustration of a support structure with a honeycomb structure.The exemplary embodiment explained below is a preferred embodiment of the invention. In the exemplary embodiment, however, the described components of the embodiment each represent individual features of the invention that are to be considered independently of one another, which also develop the invention independently of one another and are therefore also to be considered as part of the invention individually or in a combination other than the combination shown. Furthermore, the described embodiment can also be supplemented by further features of the invention that have already been described.In the figures, elements having the same function are each provided with the same reference numerals.FIG. 1 shows a vehicle interior 2 of a motor vehicle 1. the motor vehicle 1 can be, for example, a motor vehicle, in particular a passenger car. The motor vehicle 1 can have an operating device 3 in the vehicle interior 2, which can be installed, for example, in a trim part 4, for example a central console or a dashboard. The operating device 3 can provide a touchpad 5 in the vehicle interior 2, which a driver can operate with a finger 6. For this purpose, the driver can touch an operating side 7 at a touch location or a touch location 8 with the finger 6 and exert a pressing force 9 on the operating side 7. As a result, the operating device 3 can be used to record both the touch point 8 two-dimensionally, that is to say, for example, coordinates on the operating side 7, and also an amount of the contact pressure force 9. By means of the operating device 3, for example, an appliance 10 of the motor vehicle 1 can be made possible by means of the finger operation by the finger 6. The device 10 can be, for example, an infotainment system. In the example, the finger 6 represents an operating object.The operating side 7 is shown in FIG. 2 once again from a plan view as the driver can have from the interior 2 to the operating side 7. The touchpad 5 can have light symbols 11 which can be formed, for example, by recesses or a transparent filler. The light symbols 11 can be backlit, so that a driver perceives the light symbols 11 as self-luminous signs in the dark.Furthermore, it can be provided in the operating device 3 that the user receives a haptic feedback or feedback signal to his fingers 6 by the operating side 7 performing a shaking movement or a jerk or impulse or a impulse-like deflection, for example, in the surface plane of the operating surface 7. For the user, this feels as if he were operating a click switch or button.The detection of the touch point 8, the contact pressure 9, the illuminating light symbols 11 and the generation of the haptic feedback signal can be effected in the operating device 3 by means of a single printed circuit board 12, which is illustrated by way of example in a plan view in FIG. 3.The touchpad 5 can have a sensor matrix 13 for detecting the touch point 8, which matrix can be configured in a manner known per se, for example on the basis of a plurality of electrodes arranged in the form of a grid. The sensor matrix 13 can be electrically connected to a processor device 15 by means of an electrical coupling device 14, for example a cable. The processor device 15 can be a microcontroller, for example. It can be arranged on the printed circuit board 12, for example. A control signal C can be generated by the processor device 15 as a function of the contact point 8 and / or the contact pressure force 9. The device 10 can be controlled by the control signal C.For detecting the contact pressure force 9, a force sensor 16 or also a plurality of force sensors 16 can be arranged on the printed circuit board 12. The force sensor 16 may be provided, for example, on the basis of a disk spring 17, which may be connected, for example, to one or more electrodes 18 of the printed circuit board 12. By means of a further electrode 19, a distance of the disk spring 17 from the electrode 19 can be detected to the effect that an electrode signal dependent on the distance can be generated. The electrode signal can be evaluated by the processor device 15. For transmitting the contact pressure force 9 from the operating side 7 to the respective force sensor 16, the touchpad 5 can be fastened or arranged on a pivot element or pivot element 20, since FIG. 4 shows a top view once again. The pivoting element 20 can be mounted pivotably about an axis of rotation 21 and, for this purpose, can be mounted rotatably with respect to the printed circuit board 12 by means of a rotary joint device 22. In FIG. 1, the axis of rotation 21 extends perpendicular to the plane of the drawing.For generating the haptic feedback signal, an actuator 23 can be arranged on the printed circuit board 12, which actuator can be, for example, a linear motor or a piezoelectric element. The actuator 23 can be mechanically coupled to the touchpad 5, for example, via a lever element 24. In order that the touchpad 5 can move via the lever element 24 when a force is applied by the actuator 23, the touchpad 5 can be held on the pivot element 20 via spring elements 25. The spring elements 25 can have leaf springs, for example, by means of which a force transmission in a direction perpendicular to the surface plane of the operating side 7 along a transmission direction 26 is made possible, without the spring elements 25 thereby yielding elastically in a significant manner. The spring elements 25 can allow a deflection movement 27 parallel to the surface plane of the operating side 7.For illuminating the light symbols 11, the light sources 28 can be provided on the circuit board 12 for the light symbols, which light sources can be, for example, one or more light-emitting diodes. For transmitting a light 29 of the light sources 28, a light guide 30 can be provided for each light source 28, each of which can be formed from PMMA (polymethyl methacrylate), for example. The light guide 30 can be fastened to the pivot element 20, for example.When generating a control signal C, an acoustic feedback signal or operating noise can also be triggered by the processor device 15. For this purpose, a loudspeaker 31 can also be provided on the printed circuit board 12. A control device 32 provided by the processor device 15, for example, can operate the loudspeaker 31. For example, a clicking sound can be generated, as would also result if a mechanical button were operated.In the touchpad 5, the operating side 7 can be provided, for example, by a glass pane 33. Although the touchpad 5 has a glass pane 33, it can nevertheless be designed to be particularly light and be break-resistant. The low weight may be advantageous in particular in connection with generating the haptic return signal. To realize this advantage, the touchpad 5 can have one of a sandwich arrangement 34, in which the glass pane 33 and the sensor matrix 13 are bonded via or by means of an adhesive layer 35. Furthermore, a support structure 37 can form a rear side 38 of the touchpad 5 by means of a further adhesive layer 36. The support structure 37 is shown again in FIG. 5 for the purpose of illustrating a plan view. The support structure 37 may comprise a honeycomb structure 40. As a result, it can be designed to be particularly light and yet flexurally rigid. The carrier structure 37 can furthermore have through-openings 39, through which the light guides 30 can emit the light 29 to the touchpad 5 in a contactless manner. In particular, the through openings 39 prevent the light guides 30 from remaining stationary in the event of a vibration of the touchpad 5, as occurs during the generation of the haptic return signal. The through openings 39 form light channels for the light 29.The example shows how a precise implementation of a touchpad with illumination, haptics, acoustics and force evaluation can be provided.A preferred exemplary embodiment provides that a carrier with a honeycomb structure supported by flat springs is arranged on a pivot lever with a pivot point, an increase in stability and with light channels. The touch printed circuit board is adhesively attached to the carrier and the real glass surface painted from behind is adhesively attached above it with symbols.Light guides are located in the light channels, which guide light upward on the main printed circuit board via the illumination of the symbols from the LEDs. By the movable mounting of the carrier, the haptics can be produced on the main printed circuit board with the aid of the actuator. At the same time, the loudspeaker on the main printed circuit board generates the acoustics.Gesture and font recognition is performed by the touch circuit board, i.e., the sensor matrix, and the touch controller of the processor device located on the main circuit board. The pivot lever rests on the force sensors by means of its rotating mounting. These make it possible to evaluate the actuating force for specific functions on the touchpad.Overall, the example shows how a mechanical construction of a touchpad with illumination, haptics, acoustics and force evaluation can be realized by the invention.

Claims

Operating device (3) for a motor vehicle (1), having: - a pivoting element (20) mounted pivotably about an axis of rotation (21), - a touchpad (5) having a sensor matrix (13) for spatially resolved detection of a touch of an operating object (6) on an operating side (7) of the touchpad (5), - a printed circuit board (12) having at least one force sensor (16), on which the pivoting element (20) bears and on which the pivoting element (20) at least partially transmits a contact force (9) exerted by the operating object (6) on the operating side (7), - at least one light source (28) and, for each light source (28), a respective light guide (30) which is designed to transmit a contact force exerted by the operating object (6) on the operating side (7), a light (29) of the light source (28) to be guided through the pivoting element (20) to a rear side (38) of the touchpad (5) opposite the operating side (7) and to emit the light (29) in a contactless manner to a light symbol (11) provided in the touchpad (7), characterized in that the touchpad (5) is held on the pivoting element (20) in an elastically deflectable manner via a spring arrangement having at least one spring element (25), wherein in the spring arrangement the at least one spring element (25) has a leaf spring in which a longitudinal extent direction, along which the leaf spring is incompressible, is aligned perpendicular to a surface plane of the operating side (7) such that a contact force (9) is to be transmitted in a direction perpendicular to the surface plane of the operating side (7) along a transmission direction (26).The operating device (3) according to claim 1, wherein the light source (28) is arranged on the printed circuit board (12).Operating device (3) according to one of the preceding claims, wherein an electric actuator (23) is arranged on the printed circuit board (12), and the actuator (23) is mechanically coupled to the touchpad (5) via a lever element (24).Operating device (3) according to one of the preceding claims, wherein the touchpad (5) has a sandwich arrangement (34) comprising a glass pane (33), the sensor matrix (13) and a carrier structure (37).Operating device (3) according to claim 4, wherein the carrier structure (37) is at least partially configured as a honeycomb structure (40).Operating device (3) according to one of the preceding claims, wherein a loudspeaker (31) and a control circuit (32) are provided on the printed circuit board (12), and the control circuit (32) is designed to actuate the loudspeaker (31) as a function of a respective signal of the at least one force sensor (16).Operating device (3) according to one of the preceding claims, wherein a processor device (15) coupled to the sensor matrix (13) is provided on the printed circuit board (12), which is designed to determine a touch point (8) of the operating object (6) on the operating side (7) as a function of sensor signals of the sensor matrix (13).Operating device (3) according to one of the preceding claims, wherein a distance of the touchpad (5) from the axis of rotation (21) is greater than 2 centimeters, in particular greater than 5 centimeters.Motor vehicle (1) having an operating device (3) according to one of the preceding claims.

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