Touch-sensitive operating element

A touch-sensitive control element for a vehicle interior comprises a partially transparent decorative part, a functional part and a light source, wherein the functional part is arranged between the decorative part and the light source and comprises a layer of several conductors. The functional part comprises at least one first region and at least one second region, wherein the light transmittance of said at least one second region is less than the light transmittance of said at least one first region.

RELATED APPLICATION

The present invention claims priority of DE 10 2018 105 927.2, filed on 14 Mar. 2018, the entirety of which is incorporated herein by reference.

FIELD OF THE DISCLOSURE

The disclosure concerns a touch-sensitive operating element for a vehicle interior.

BACKGROUND

Operating elements are usually designed to be touch-sensitive in modern vehicles, thus making it possible to improve the operating comfort on the one hand and to reduce the production costs on the other.

These operating areas usually have backlighting. For this purpose, a light source is provided in the operating element that illuminates the surface of the operating element that is visible from the vehicle interior.

Owing to constructional constraints or other factors, it is not always possible to position the light source in the operating element optimally so that inhomogeneities in the light intensity are recognizable on the user interface of the operating element that is visible to the passenger. The operating element then looks wrong or poorly illuminated.

SUMMARY

It is therefore the object of the disclosure to provide a touch-sensitive operating element in which the operating area facing the vehicle interior is illuminated homogenously.

The object is achieved by means of a touch-sensitive operating element for a vehicle interior comprising a partially transparent decorative part, a functional part and a light source, wherein the functional part is located between the decorative part and the light source and comprises a layer of several conductors. The functional part comprises at least one first region and at least one second region, wherein the light transmittance of said at least one second region is less than the light transmittance of said at least one first region.

As the functional part comprises regions with differing light transmittances, the regions of the decorative part that are illuminated too much by the light source can be darkened by appropriate configuration of the second region. In this way, differences in the illumination of the decorative part and thus in the light intensity on the side of the decorative part facing the vehicle interior can be balanced out until the light intensity is homogenous.

As the regions are created by the necessary functional part in any case, only very slight additional costs are required.

The operating element can be illuminated, for example, by the light source illuminating the decorative part through the functional part.

As a result, the conductors have a lower light transmission or are nontransparent in comparison to the rest of the functional part, with respect to at least the light generated by the light source.

The light source can be a LED or several LEDs.

The light source, in particular the LED(s), is located, for example, only in a part of the second region. The light source, in particular the LED(s), is not provided, for example, all over in the second region or under the second region.

For example, the light source, in particular the LED, is provided in not the first region and/or only the second region. Thus, the light source does not extend, for example, over the entire region of the conductors.

For example, interstices are located between the conductors on the layer, wherein the ratio of the area of the conductors to the area of the interstices of the layer is larger in said at least one second region of the functional part than in said at least one first region of the functional part. Thus, the light transmittance of the second region can be reduced easily as no additional darkening components are required.

The area of the conductors or the interstices is understood to mean the area occupied by the conductors or interstices on the layer. In other words, the ratio is larger, the more the area is occupied by the conductors. Moreover, the light transmittance of the relevant area decreases as the ratio increases.

For example, said at least one first region and said at least one second region are designed and/or located in such a way that the light intensity on the side of the decorative part facing away from the light source is substantially homogenous. In this way, the operating element appears to vehicle occupants to be illuminated uniformly.

The homogeneity of the light intensity is determined in particular via the greater part of the surface or the operating area or via the overall surface or operating area of the decorative part.

In a variant, said at least one second region comprises several subregions, wherein the ratio of the area of the conductors to the area of the interstices differs between the subregions, thus making it possible for complex fluctuations in the intensity to be also balanced.

To improve the homogeneity further, the ratio of the area of the conductors to the area of the interstices can change continuously or successively in said at least one first region and/or said at least one second region.

For example, the ratio of the area of the conductors to the area of the interstices between two of the regions or subregions is thus increased by increasing the width of the conductors and/or decreasing the width of the interstices, thereby not impairing the function of the functional part.

The conductors can be between 25 μm and 200 μm in width. The interstices, i.e. the distance between the conductors, can be between 100 μm and 300 μm in width.

To achieve a particularly uniform light intensity, at least one part of said at least one second region is provided above the light source.

In an embodiment of the disclosure, the conductors are located substantially in a plane that forms the layer. As a result, the functional part can be design flatly.

Substantially in a plane means within the scope of this disclosure that a possible curvature of the functional part and/or the decorative part is disregarded.

Preferably, the functional part comprises a transparent film on which the conductors are applied, thus enabling the functional part to be produced simply.

In a particularly efficient configuration, the conductors extend parallel to each other, the conductors at least partially form a grid, and/or the conductors at least partially form a honeycomb structure.

The functional part may comprise a principal direction, wherein the conductors run in a transverse direction to the principal direction, in a diagonal direction to the principal direction and/or in the principal direction.

To simplify the assembly, the functional part can be attached to the decorative part, in particular adhered to the decorative part.

In an embodiment, the decorative part comprises an operating area for a vehicle occupant in order to facilitate ease of use of the operating element.

Thus, the surface of the decorative part facing away from the functional part can comprise the operating area. For example, the operating area is the section of the surface of the decorative part on which a touch can be recognized or in which the conductor or the layer is provided in the corresponding section of the functional region.

For example, the decorative part is painted or lacquered and/or has been provided with a mark such as a symbol, e.g. by means of laser-beam machining.

To improve the luminous efficacy, the light source can be provided in a cavity of the operating element which is closed on one side by the functional part and/or the operating element can feature a reflector that is provided at least in part between the light source and the functional part.

For example, the side walls of the cavity are at least in part reflective or designed as reflectors.

Preferably, the operating element has a control unit that is electronically connected to the conductors and is configured to recognize a touch on the decorative part. In this way, the ease of use of the operating element is made possible. The touch can occur in particular through the use of a finger.

DETAILED DESCRIPTION

InFIGS. 1 and 2, a touch-sensitive operating element10is schematically shown for a vehicle.

The operating element10is provided, for example, in a dashboard12of a vehicle, i.e. in the vehicle interior.

The operating element10allows a passenger in the vehicle interior to operate a certain vehicle function, in the shown example the electric parking brake. However, all other well-known functions of operating elements or buttons are also conceivable, such as the activation of an air conditioning system, the window regulator or the like.

The operating element10comprises a decorative part14, a functional part16, a cavity18, a light source20and a control unit21.

The light source20is, for example, a LED. The light source20emits light with a certain wavelength or a certain known spectrum of wavelengths.

The light source20can also comprise a group of LEDs or one or more incandescent light bulbs.

The decorative part14forms the cover of the operating element10visible to the passenger and, for example, can be flush with the dashboard12.

The decorative part14thus comprises the actual operating area22of the operating element10, i.e. that area that must be touched by the vehicle occupant in order to operate the operating element10and actuate the relevant function.

The decorative part14is painted or coated with a nontransparent coating in the shown embodiment.

In this regard, when referring to light in general within the scope of this disclosure, this refers to the light emitted by the light source20or the corresponding light waves.

The paint or coating is partially removed from the layer of paint or coating, for example by means of a laser, so that a mark, such as a symbol24, is visible on the decorative part14. This symbol illustrates the vehicle function allocated to the operating element10. This is the electric parking brake inFIG. 2.

The symbol24is located preferably on the operating area22and the decorative part14is at least partially transparent in the area of the symbol24.

The functional part16is attached, in particular adhered, to the decorative part14on the side of the decorative part14facing away from the vehicle interior.

The functional part16comprises a transparent film26in the shown embodiment and a layer28of electrical conductors30applied thereto (FIG. 3).

The conductors30have a lower light transmission as the film26or are nontransparent. For example, they are made of metal.

The cavity18, in which the light source20is provided, is connected to the functional part16.

The functional part16closes the cavity on the side towards the vehicle interior.

The light source20is located on the side of the cavity18facing away from the vehicle interior.

On this side, the cavity18can be opened or closed by a base.

The cavity18comprises side walls32on which reflectors34are provided towards the cavity18.

In the shown embodiment, the side walls32are themselves reflective and thus form the reflectors34.

InFIG. 3, the operating element10is shown in a top view, wherein the decorative part14and the side walls32are not represented for the sake of clarity.

Therefore, only the functional part16, more specifically the film26and the layer28comprising the conductors30, as well as the light source20represented as dashed lines are recognizable.

InFIG. 3, the configuration of the conductors30on the layer28is easily recognizable.

The conductors30are applied, for example vapor-deposited, on the film26and are therefore located substantially in a plane that is stretched by the film26.

As the film26is movable, and, if necessary, adapted to a curvature of the decorative part14or another contour of the decorative part14, the plane is also, if necessary, not flat in a geometric sense.

In the shown embodiment, the layer28is slightly smaller than the film26and thus the decorative part14. It is however conceivable that the layer28is the same size as the film26and the decorative part14.

The layer28or the overall functional part16is formed substantially rectangularly and therefore has a longitudinal direction that represents a principal direction H. The principal direction H would be the direction of one of the principal axes in the case of a conceivable elliptical embodiment of the functional part16or the layer28.

The conductors30of the layer28are connected electrically to the control unit21of the operating element10in order to recognise a touch by a user on the decorative part14in a known way.

To this end, the control unit21activates the conductors30accordingly and measures a change in the measurement values, such as the capacity caused by a touch. If necessary, a further layer of conductors that is connected to the control unit21is required for this (not shown).

The operating area22thus becomes touch-sensitive through the layer28interacting with the control unit21, i.e. the touch by the user on the operating area22with a finger or a suitable input device is recognized.

The operating area22thus equals the region of the surface of the decorative part14facing the vehicle interior, by providing the layer28on the opposite side.

In the first embodiment shown inFIG. 3, the conductors30are designed in the layer28as straight or conducting paths that run parallel to each other.

The conductors30run transversely or perpendicularly to the principal direction H. However, it is conceivable that the conductors30run in the principal direction H or parallel to it.

The conductors30have a width and are spaced apart from each other, wherein an interstice38is provided in each case between the conductors30. In the interstice38, the film26is primarily transparent, whereas the film26and thus the functional part16are nontransparent in the regions that are occupied by a conductor30.

The functional part16comprises two different regions, namely a first region40and a second region42. As an illustration, the first and the second regions40,42are shown separated from each other by a dashed line inFIG. 3.

The difference between the two regions40,42is that the conductors20and/or the interstices38differ in the regions40,42.

The conductors30have a width b1, and a spacing a1in the first region40. The spacing a1is measured for example from the centerline to the centerline of two adjacent conductors30.

The conductors30have a width b2and a spacing a2in the second region42.

In the first embodiment shown inFIG. 3, the width b2of the conductors30in the second region42is larger than the width b1of the conductors30in the first region40. At the same time, the spacing a2of the conductors30in the second region42is smaller than the spacing a1of the conductors30in the first region40.

However, it is also conceivable that the regions40,42differ from each other only in the width of the conductors30or the spacings of the conductors30.

For example, the width b1of the conductors30in the first region40is between 25 μm and 200 μm, in particular at 50 μm. The spacing a1of the conductors30in the first region40is between 100 μm and 200 μm, in particular at 150 μm.

In contrast, the width b2of the conductors30of the second region42is between 100 μm and 200 μm, in particular at 150 μm, and/or the spacing a2of the conductors30of the second region42is between 200 μm and 300 μm, in particular at 250 μm

Owing to the larger width of the conductors30and the smaller width of the interstices38which depends on the width of the conductors30and the spacing of the conductors, the ratio of the area of the conductors30to the area of the interstices38in the second region42is larger than this ratio in the first region40.

In this regard, the area of the conductors30or the interstices38is understood to mean the area occupied by the conductors30or the interstices38on the film26. The ratio results from the area of the conductors30divided by the area of the interstices38.

In other words, the ratio is larger, the more area is occupied by the nontransparent conductors30on the film26. Thus, the light transmittance in the second region42is less than in the first region40.

As can be seen inFIG. 3and also inFIG. 1, the second region42is provided at least in part above the light source20and the remaining region of the film26forms the first region40.

In this regard, above means for example that an imaginary line from the light source20runs perpendicular to the decorative part14through the second region42.

The light source can be a LED or several LEDs.

The light source20is only located, for example, in a part of the second region42or below the second region42. The light source20is not provided in particular all over the second region42or under the second region42.

For example, the light source20is not provided in the first region40and/or the light source20is only provided in the second region42. Thus, the light source40does not extend, for example, over the entire region of the conductors30.

During the operation of the light source20, the light emitted by the light source20illuminates the decorative part14through the functional part16

To this end, owing to the differing regions40,42, the light transmittance of the functional part16is thus adapted to the light source20, its layer and/or the embodiment of the cavity18and the reflectors34so that the light intensity that is viewed on the operating area22from the vehicle interior or that exists on the entire decorative part14is substantially homogenous over the operating area22and the entire decorative part14. The regions40,42comprising different light transmittances of the functional part16, i.e. the layer and its respective light transmission, are selected accordingly.

In this way, a consistent illumination of the decorative part14and the marks, in particular the symbol24, is achieved.

InFIGS. 4, 5 and 6, further embodiments of the disclosure are shown which substantially correspond to the first embodiment of theFIGS. 1 to 3. Therefore, only the differences are discussed hereinafter and the same parts and parts with the same function are provided with the same reference signs.

The conductors run diagonally to the principal direction H in the second embodiment shown inFIG. 4.

Moreover, in contrast to the first embodiment, an abrupt leap in the width b1and in the spacing a1does not occur from the first region40to the width b2or the spacing a2of the second region42, but rather the transition from the first region40to the second region42occurs successively or continuously.

Thus, the ratio of the area of the conductors30to the area of the interstices38changes continuously or successively.

The first region40and the second region42transition into each other in this case.

A third embodiment is shown inFIG. 5, wherein in contrast to the first embodiment, the conductors30do not run parallel in this embodiment, but rather form a honeycomb structure.

As in the first embodiment, the conductors30are thinner and the spacings a1are larger in the first region so that larger honeycombs of the honeycomb structure are formed.

The honeycombs of the honeycomb structure are therefore smaller in the second region42.

In the fourth embodiment shown inFIG. 6, the conductors30run perpendicular to each other and form a grid.

Moreover, the second region42comprises a first subregion44and a second subregion46, wherein the first subregion44surrounds the second subregion46.

The ratio of the area of the conductors30to the area of the interstices38is larger in the second subregion46than in the first subregion44. In comparison to the first region40, the ratio of the area of the conductors30to the area of the interstices38is larger in both subregions44,46.

This is achieved in the fourth embodiment by changing the spacings between the conductors30so that the grid is denser, or rather the grid points are closer together in the second subregion46as in the first subregion44.

Of course, features of the various shown embodiments can be combined with each other as desired. Thus, for example, a gradual transition is easily possible between the regions40,44,46in the fourth embodiment

It is also conceivable that different configurations of the conductors30are used in different regions40,42. For example, the conductors30can run in the principal direction H in the first region and diagonally to this in the second region42or form a gird or honeycomb form.