INPUT DEVICE FOR ASCERTAINING MANUAL OPERATION

Abstract

The invention relates to an input device (10) for ascertaining manual operation, having a touch-sensitive sensor element (12) that is mounted movably such that it is movable in a direction of operation (14) on the manual operation, the touch-sensitive sensor element (12) being mechanically coupled to a force sensor element (16).

Claims

1-11. (canceled)

12. An input device for ascertaining a manual operation, comprising: a touch-sensitive sensor element mounted movably in a direction of operation of the manual operation; and a force sensor element, mechanically coupled to the touch-sensitive sensor element, having a capacitive measuring unit measuring capacitance, and a reference capacitive measuring unit providing a reference signal, the force sensor element producing a force signal by taking into consideration the capacitance and the reference signal provided by the reference capacitive measuring unit.

13. The input device according to claim 12, wherein the force sensor element produces an electrical force signal, corresponding to a force acting on the touch-sensitive sensor element, by assigning a value from a prescribed plurality of at least three values based on an explicit assignment instruction.

14. The input device according to claim 12, further comprising a prestress force element prestressing the touch-sensitive sensor element with a prescribed force in the direction of operation.

15. The input device according to claim 14, wherein the prestress force element includes at least one spring exerting the prescribed force on the touch-sensitive sensor element towards the force sensor element.

16. The input device according to claim 15, wherein the touch-sensitive sensor element includes a contact-connection projection in the direction of operation, providing mechanical coupling of the force sensor element to the touch-sensitive sensor element.

17. The input device according to claim 16, wherein the touch-sensitive sensor element outputs a touch signal, and wherein the input device further comprises a hardware processor, receiving the touch signal from the touch-sensitive sensor element and the force signal from the force sensor element, programmed to output an operating signal based on the touch signal and the force signal.

18. The input device according to claim 17, wherein the hardware processor outputs the operating signal indicating a touch on the touch-sensitive sensor element when a difference between the capacitance and the reference signal is greater than a first predetermined value when the touch signal indicates that the touch-sensitive sensor element is being touched.

19. The input device according to claim 12, wherein the touch-sensitive sensor element includes a contact-connection projection in the direction of operation, providing mechanical coupling of the force sensor element to the touch-sensitive sensor element.

20. The input device according to claim 12, further comprising an actuator mechanically coupled to the touch-sensitive sensor element.

21. The input device according to claim 12, wherein the touch-sensitive sensor element is formed integrally with the force sensor element.

22. The input device according to claim 12, wherein at least the force sensor element is arranged in moisture-proof fashion.

23. The input device according to claim 12, further comprising an evaluation unit ascertaining the manual operation by receiving, and evaluating in combination, a touch signal delivered by the touch-sensitive sensor element and the force signal delivered by the force sensor element, the evaluation unit performing a combined evaluation of the touch signal and the force signal as a basis for outputting an operating signal.

24. A motor vehicle, comprising: a chassis; and an input device producing an operating signal in response to a manual operation, including a touch-sensitive sensor element mounted movably in a direction of operation of the manual operation; and a force sensor element, mechanically coupled to the touch-sensitive sensor element, having a capacitive measuring unit measuring capacitance, and a reference capacitive measuring unit providing a reference signal, the force sensor element producing a force signal by taking into consideration the capacitance and the reference signal provided by the reference capacitive measuring unit.

25. The motor vehicle according to claim 24, wherein the input device further comprises a prestress force element prestressing the touch-sensitive sensor element with a prescribed force in the direction of operation.

26. The motor vehicle according to claim 25, wherein the prestress force element includes at least one spring exerting the prescribed force on the touch-sensitive sensor element towards the force sensor element.

27. The motor vehicle according to claim 26, wherein the touch-sensitive sensor element includes a contact-connection projection in the direction of operation, mechanically coupling the force sensor element and the touch-sensitive sensor element.

28. The motor vehicle according to claim 27, wherein the touch-sensitive sensor element outputs a touch signal, and wherein the input device further comprises a hardware processor, receiving the touch signal from the touch-sensitive sensor element and the force signal from the force sensor element, programmed to output an operating signal based on the touch signal and the force signal.

29. The motor vehicle according to claim 24, wherein the touch-sensitive sensor element includes a contact-connection projection in the direction of operation, mechanically coupling the force sensor element and the touch-sensitive sensor element.

30. The motor vehicle according to claim 24, wherein the touch-sensitive sensor element outputs a touch signal, and wherein the input device further comprises a hardware processor, receiving the touch signal from the touch-sensitive sensor element and the force signal from the force sensor element, programmed to output an operating signal based on the touch signal and the force signal.

31. The motor vehicle according to claim 30, wherein the hardware processor outputs the operating signal indicating a touch on the touch-sensitive sensor element when a difference between the capacitance and the reference signal is greater than a first predetermined value when the touch signal indicates that the touch-sensitive sensor element is being touched.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] These and other aspects, advantages and features can be found in the following description of an exemplary embodiment with reference to the accompanying drawing. The exemplary embodiment serves merely to explain the invention and is nonlimiting therefor. Reference symbols used in the drawing denote like components and functions.

[0026] The single FIGURE is a cross section of an input device in which a touch pad is mechanically coupled as a touch-sensitive sensor element to a force sensor element.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0027] Reference will now be made in detail to the preferred embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

[0028] The single FIGURE shows an input device 10 that is used for ascertaining manual operation. The input device 10 has a touch pad 12 as a touch-sensitive sensor element that is mounted movably in a direction of operation 14 of manual operation. In the present case, the touch pad 12 is in the form of a capacitive touch pad and is electrically connected to an evaluation unit, not depicted. The touch pad 12 detects operation by a finger 22 of a user and delivers a corresponding signal to the evaluation unit. In the present case, the touch pad 12 is in the form of a rigid, plate-like assembly and mounted displaceably in the direction of operation 14. The displaceable mounting is not depicted further here, because it may be configured arbitrarily in principle without altering the core concept of the input device. The touch pad 12 is arranged in an opening, not denoted, in a housing 24 of the input device 10. When the finger 22 is used to exert a compressive force on the touch pad 12 in the direction of operation 14, the position of the touch pad 12 as depicted in the FIGURE is displaced relative to the housing 24, likewise in the direction of operation 14. In the present case, the operating principle of the touch pad 12 is based on sensing of capacitive changes. Alternatively, however, it is also possible to use a touch pad whose operating principle is based on sensing of optical changes.

[0029] In the FIGURE, a force sensor element 16 is arranged beneath the touch pad 12. The force sensor element 16 is mechanically coupled to the touch pad 12 via a plunger 18, connected to the touch pad 12 on the reverse, as a contact-connection projection. The plunger 18 points from the touch pad 12 in the direction of the force sensor element 16. The touch pad 12 and the plunger 18 are formed integrally with one another in the present case. The arrangement is chosen such that the plunger 18 is in contact with the force sensor element 16.

[0030] The force sensor element 16 has a printed circuit board 26 on which a conductor track arrangement is provided that, together with a cover 32 made of sheet brass, forms a capacitive measuring unit 20. For this purpose, the printed circuit board has a conductor track 28 in annular form within which a further annular conductor track 30 is arranged in a manner electrically insulated from the conductor track 28. The cover 32, like the conductor track 28, is likewise in annular form with a comparable radius, so that its outer circumference is supported on the conductor track 28. At the same time, the cover 32 is curved, so that there is a distance between the cover 32 and the conductor track 30. This arrangement produces a capacitance between the conductor tracks 28, 30 that is able to be measured by a capacitance measuring unit, not depicted. The capacitance measuring unit delivers a corresponding force signal likewise to the evaluation unit.

[0031] The capacitance of the capacitive measuring unit 20 is dependent on how great the distance is between the conductor track 30 and the cover 32. When the plunger 18 is used to exert a compressive force acting in the direction of operation 14 on the touch pad 12 by the finger 22, the touch pad 12 and the plunger 18 connected thereto are displaced in accordance with the action of force. As a result, the plunger 18 pushes on the cover 32, so that the curvature thereof is reduced. Overall, this reduces the distance between the cover 32 and the conductor track 30, so that the capacitance of the capacitive measuring unit 20 is increased. Accordingly, the capacitive measuring unit 20 produces a corresponding signal that is transmitted to the evaluation unit.

[0032] The evaluation unit receives the signals from the touch pad 12 and from the force sensor element 16 and produces a control signal only if an adequate signal from both the touch pad 12 and the force sensor element 16 has been sensed. For this purpose, the signals can each be compared with a comparison value, the control signal being produced only if each of the signals by itself exceeds the comparison value respectively associated with it.

[0033] In order to ensure a reliable connection between the plunger 18 and the cover 32, there is further provision for the touch pad 12 to have a force applied to it relative to the housing 24 in the direction of the force sensor element 16. For this purpose, prestressing springs 34 are provided that are arranged between the housing 24 and the touch pad 12. The prestressing springs 34 thus produce a prestress in the direction of operation 14, that is to say in the same direction as that in which a compressive force acts that a user applies to the touch pad 12 with his finger 22 in order to activate an operating function.

[0034] The FIGURE does not depict that the capacitive measuring unit 20 is protected against moisture. For this purpose, a cavity 36 that is formed between the cover 32 and the printed circuit board 26 is filled with an elastic, compressible plastic. This ensures that the entry of moisture or liquid into the cavity 36 is largely prevented. This is because the entry of liquid or moisture can alter or corrupt the capacitance of the capacitive measuring unit 20 on account of different dielectric properties, meaning that reliable functioning could be impaired. The sealing function now precludes this possibility, so that permanently reliable functioning of the capacitive measuring unit 20 can be achieved.

[0035] The design as has just been described furthermore has the advantage that the plunger 18 no more needs to be permanently connected to the cover 32 than the cover 32 to the conductor track 28. For the intended functioning, it is sufficient for the relevant components to be arranged as depicted in the FIGURE. The prestress produced by the prestressing springs 34 then allows cohesion of the structure to be achieved.

[0036] The exemplary embodiment serves merely to explain the invention and is nonlimiting therefor. Naturally, it is possible for functions to be designed arbitrarily, particularly also with reference to the evaluation or acoustic coupling, without departing from the concept of the invention. Furthermore, the invention is naturally not limited just to use in vehicles, but rather can naturally be used for any input devices, that is to say including for radios, domestic appliances or the like. The effect that can be achieved by the force sensor is that operation can be identified reliably.

[0037] Finally, it should be noted that the advantages and features and also embodiments described for the device according to the invention apply in equal measure to a corresponding method, and vice versa. Therefore, corresponding method features may be provided for apparatus features, and vice versa.

[0038] A description has been provided with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the claims which may include the phrase “at least one of A, B and C” as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 358 F3d 870, 69 USPQ2d 1865 (Fed. Cir. 2004).