A function display for selectively displaying several symbols

Abstract

The invention relates to a functional display having at least one light guide with a planar display portion having two opposite main surfaces which face the viewer as display surfaces and a further main surface which faces away from the viewer, and at least two light input portions, a plurality of light sources, the light being introduced into the light guide via one of the light input portions of the light guide which is located immediately adjacent to the respective light source, at least one of the main surfaces of the display portion of the light guide being surface-structured by means of a plurality of microstructures which are introduced into the respective main surface and cause light refraction and / or light scattering, so that at least two surface-structured interface regions are present as sub-regions of the respective main surface in the light guide, the sub-regions being arranged laterally offset from one another from the viewpoint of the viewer and representing symbols, the light introduced into the light guide being emitted towards the viewer as a result of the light refraction and / or light scattering in the surface-structured interface regions when the light sources are activated respectively.

Description

Technical Field

[0001] The present invention relates to a functional display for selectively displaying a number of symbols representing corresponding switching functions and / or switching states. Background Technology

[0002] For example, such functional displays are needed in multi-functional control elements to visualize switching functions and / or switching states associated with the control element. Electronic pixel matrix displays are frequently used for this purpose. However, they are relatively expensive, and their predominantly rectangular shape limits innovative design and placement. Furthermore, electronic pixel matrix displays often exhibit "aging" when displaying static content; that is, the displayed content remains undesirably visible even when the display is turned off due to optically perceptible damage to the display's imaging layer. Additionally, these electronic pixel matrix displays consume relatively high power. Moreover, in some applications, the use of ordinary electronic pixel matrix displays is prohibited due to the risk of injury, such as in the event of a head impact. As an alternative to pixel matrix displays, it is known to selectively emit light from the end face of a light guide by means of surface structures on the main surface used as the display surface, where the area with the surface structure is only locally positioned and displays symbols or the like. Here, the disadvantage is that each light guide can only backlight one symbol, because if multiple symbols are attempted to be set through the surface-structured area in a single light guide, multiple symbols will be backlit simultaneously due to uncontrolled light propagation within the light guide. Another solution is to use exactly one light guide for each symbol and stack these light guides. However, this results in a relatively large functional display with the same number of symbols, and due to the large number of light guides, it has the disadvantage that not only is the transparency of the functional display affected, but the contrast is also worse, thus making the symbols on the lower, stacked light guides further away from the viewer less visible. For example, this can ultimately lead to viewers, especially drivers, misjudging, for example, the actual switch status. Summary of the Invention

[0003] In this context, the object of the present invention is to provide a functional display with the possibility of selectively activating the backlight of a single symbol among a plurality of symbols, which can save structural space and improve the visibility of the symbols, without affecting the creative freedom in the design of the functional display, with low manufacturing cost, energy efficiency and reliability and / or reduced risk of injury, especially in the case of head impact.

[0004] This objective is achieved by the functional display according to claim 1. The integrated functional display and thus correspondingly advantageous control elements, as well as the steering wheel containing operating elements, are the subject of the corresponding parallel claims. Advantageous designs are the subject of the corresponding dependent claims. It should be noted that the features individually listed in the claims can be combined with each other in any technically reasonable manner, and other designs of the invention are indicated. This specification, in particular, describes and illustrates the invention additionally with reference to the accompanying drawings.

[0005] This invention relates to a functional display, particularly for motor vehicles, for selectively displaying a plurality of symbols representing corresponding switching functions and / or switching states. Selective display is understood not only as selectively displaying different symbols from a plurality of predetermined symbols, which in this solution is achieved by selectively selecting one or more light sources from a plurality of light sources and energizing them, but also as turning the light sources on and off so that the symbols are selectively presented to the viewer by activating backlighting, or by turning off backlighting so that the symbols are as close as possible to disappear from the viewer's perception.

[0006] The functional display according to the invention includes at least one light guide made of a transparent or translucent material. The light guide has a planar display portion having two opposing main surfaces, wherein the main surface faces the viewer, such as a vehicle driver, and is the display surface in a conventional arrangement of a functional display, while the other main surface faces away from the viewer. The display portion of the light guide, for example, has two opposing, preferably parallel, main surfaces connected via end faces that form common edges with the main surfaces of the light guide, for example, on the narrow and longitudinal sides of the light guide. For example, the end faces are orthogonal to at least one or both main surfaces of the light guide. For example, the material constituting the light guide is a plastic, preferably a thermoplastic, such as polyethylene (PE), polycarbonate (PC), polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), acrylonitrile-butadiene-styrene (ABS), or polymethyl methacrylate (PMMA) or glass. The main surfaces can be understood, for example, as those surfaces of the light guide having the largest surface area. Preferably, the main surfaces are designed to be substantially flat, except for the surface structuring described below. The light guide may have a transparent or translucent coating, such as a varnish coating. The light guide also has at least two light input sections. For example, the display section and multiple light input sections are integrally formed. Here, the light input sections are each configured as a loop-shaped protrusion of the display section. According to another design, the light input sections and the display section are each configured as a separable portion of the light guide. In one design, the light input sections and the display section have the same material thickness, for example, determined perpendicular to the main surface facing the viewer.

[0007] According to the present invention, the functional display has two light sources arranged such that their light enters the light guide via one of the adjacent light input portions of the light guide, and is further guided in the lateral direction from the viewer's perspective into the display portion of the light guide. Preferably, for each light input portion, an adjacent light source is provided.

[0008] According to the invention, at least one of the main surfaces of the display portion is surface-structured by means of a plurality of microstructures introduced into the respective main surfaces to cause light refraction and / or light scattering, thereby constructing at least two surface-structured boundary surface regions as sub-regions of the respective main surfaces in the light guide, wherein the two surface-structured boundary surface regions are arranged staggered in the lateral direction from the viewer's perspective and each represents a symbol. Preferably, the surface-structured boundary surface regions do not overlap, and more preferably, the surface-structured boundary surface regions are arranged spaced apart from each other. A microstructure is understood, for example, as a single bulge or a single depression on the main surface. Here, the maximum size of each microstructure is in the range of 1 to 50 μm, preferably in the range of 1 to 25 μm. Preferably, the microstructures are evenly spaced across the entire surface-structured region of the main surface. Preferably, the main surface facing the viewer is provided with microstructures. For example, the microstructures are shaped like pyramids or prisms. Preferably, the microstructures are constructed in the same shape, and more preferably, they are not only uniformly shaped but also have a uniform orientation. When each microstructure can be mapped to an adjacent microstructure by a hypothetical linear movement, for example, a consistent orientation is achieved in a flat main surface. Even more preferably, the microstructures are configured such that they generate a collimated beam of light emitted from the light guide, which originates from a light source and previously enters the light guide via an end face.

[0009] When the light sources are activated separately, according to the invention, light entering the light guide is emitted towards the viewer due to light refraction and / or light scattering in the surface-structured boundary surface regions, thus making the symbols displayed by the surface-structured boundary surface regions visible to the viewer. The surface structure results in, for example, enhanced light emission towards the viewer compared to a flat design of the associated main surface, due to light refraction and / or light scattering. For example, the microstructured light is incident at an angle predetermined by the microstructure, such that the angle does not satisfy the total internal reflection condition, causing light L, L' to leave the light guide in the microstructure region. According to the design of the functional display according to the invention, each light guide is provided with multiple backlight symbols, which can be backlit independently and selectively due to individual backlighting via separate light input portions. Since each light guide can carry multiple symbols, the number of light guides can be reduced, which not only saves structural space but also improves the display quality of the functional display.

[0010] In order to improve light incidence and / or adapt the light emission characteristics of the light source to the incident surface of the light input section determined for light to enter the light guide, it is preferable to arrange a lens between the light guide and the light source or to add a lens structure to the incident surface.

[0011] According to the invention, a device for mutual shielding of the light input portions and / or light sources is also provided. For example, the device is designed such that light already incident on the light input portion is as unlikely as possible to escape and incident on adjacent light input portions. Additionally or alternatively, the device is designed such that light from the light source is transmitted as much as possible only to the associated, adjacent light input portion, while surrounding, non-associated light input portions are shielded relative to non-associated light sources.

[0012] Preferably, the devices for mutually blocking light have an opaque coating on the respective light input portions. For example, the opaque coating is provided at least on the surface of the light input portion facing the adjacent light input portion.

[0013] The device for mutual shading has at least one partition with a partition opening that opens toward the associated light input portion.

[0014] Preferably, the light input portion of the light guide and the surface-structured boundary surface regions are arranged such that each surface-structured boundary surface region is opposite to a light input portion, and more preferably, they are adjacent to each other. Therefore, light from the light input portion is prevented from reaching other surface-structured boundary surface regions of the same light guide, except for the corresponding associated surface-structured boundary surface regions.

[0015] Therefore, the light input portion of the light guide and the surface-structured boundary surface region are preferably arranged such that light entering the light input portion each time will not reach more than one surface-structured boundary surface region without internal reflection in the light guide.

[0016] The light input portion of the light guide is preferably arranged such that its extension directions always do not appear to intersect in the light propagation direction and are, for example, parallel to each other.

[0017] The light input portion of the light guide preferably always has a pair of opposing wings, through which the corresponding light input portions of the wings converge into the display portion. The envisioned tangential extension of the wings defines an envisioned portion volume in the associated display portion, within which only one surface-structured boundary surface region is arranged.

[0018] The display portion is preferably coated with a reduced reflective coating to obtain a coating commonly referred to as an anti-reflective coating or protective layer. It has the task of reducing, for example, the amount of light reflected into the light guide at the coated end face compared to the uncoated end face through light absorption in the coating. This can be applied comprehensively, except for the light incident area set for the light source in the light input portion.

[0019] Preferably, when each conductor activates only the light source associated with the light input portion, the maximum light density of the light radiation of one surface-structured boundary surface region is dominant relative to the rest of the surface-structured boundary surface regions, i.e., the brightest, while the corresponding maximum light density of the rest of the surface-structured boundary surface regions is not greater than two percent of the maximum light density of the dominant surface-structured boundary surface region.

[0020] The light input portions preferably each have an incident surface facing an adjacent light source, said incident surface not perpendicular to the main surface of the display portion of the light guide. The incident surface of the light input portion is preferably parallel to at least one main surface of the display portion of the light guide.

[0021] In one design, from the viewer's perspective, the light sources are arranged next to the adjacent light input sections. Preferably, from the viewer's perspective, the light sources are arranged below the adjacent light input sections.

[0022] Surface structuring is introduced into the display portion of the light guide, for example, through laser ablation. The boundary surface regions of the surface structuring are preferably created by pressing and / or molding. For example, microstructures are introduced into the corresponding main surface or surface by vacuum forming or by means of tool die casting, wherein the shaped surface of the tool is pre-designed to transfer the structure to the display portion of the light guide.

[0023] According to a preferred design configuration, the surface-structured boundary surface region of the light guide has a uniformly formed three-dimensional microstructure. More preferably, the average number density is in the range of 400 to 7,000 per square millimeter, and most preferably in the range of 400 to 4,000 per square millimeter. It has been shown that when the light source is on, this number density produces a brightness distribution sufficient for optical recognition, while remaining inconspicuous when the light source is off, making the surface-structured region unrecognizable to the "unarmed" eye at the expected viewing distance, particularly undisturbed by possible perspective through a functional display.

[0024] For each light guide of the functional display, the area of ​​all surface-structured boundary surface regions of the display portion on the corresponding main surface of the display portion visible to the viewer shall not exceed 0.5, preferably not exceed 0.3.

[0025] The functional display preferably includes a plurality of light guides arranged in a stacked manner, wherein at least one of them is a surface-structured boundary surface region with a plurality of representation symbols, and more preferably, all of them are multiple surface-structured boundary surface regions with representation symbols.

[0026] According to a preferred design, the display portion is constructed transparently to the viewer in the area outside the surface region of the surface structured boundary.

[0027] To prevent unwanted light propagation in the light guide, particularly when affected by external light, according to a preferred embodiment, the light guide has an anti-reflective coating on at least one end face, preferably the end face opposite the end face facing the light source. This coating is also commonly referred to as an anti-reflective coating or protective layer. It has the task of reducing, for example, the amount of light reflected into the light guide from the coated end face compared to an uncoated end face by light absorption in the coating. This can be applied comprehensively, except for the light incident area set for the light from the light source, for example. The invention also relates to a control element having a specific control section for touch or operation, wherein a functional display of one of the above embodiments is integrated within the control section. The control element, for example, has feet for securing the control element to a vehicle component, such as a dashboard, a passenger compartment panel, or particularly the steering wheel rim of a motor vehicle steering wheel. Here, for example, the main surface serving as the display surface constitutes the specific control section for touch or operation of the control element, or it is arranged under a partition that is at least partially transparent, constituting the control surface, such that the main surface is visible through the partition. The control section is configured, for example, as at least one cantilever arm. The cantilever arm is mounted on the foot, for example, by means of a solid joint, so that when an operating force is applied perpendicularly to the control surface, the control unit can pivot about a predetermined pivot axis against the restoring force relative to the foot. Additionally, a device is provided to detect the amount of pivoting between the control unit and the foot. The region of the component that allows pivoting between two rigid body regions through bending is called the solid joint. The solid joint ensures backlash-free and therefore noiseless support for the control unit on the foot. The foot and control unit are made of thermoplastic materials, for example, polyethylene (PE), polycarbonate (PC), polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), acrylonitrile-butadiene-styrene (ABS), or polymethyl methacrylate (PMMA). The control element according to the invention is particularly suitable for designs where the maximum pivoting amount about the predetermined pivot axis A from the unoperated rest position to the maximum operating pivot position is less than 10°, preferably less than 5°.

[0028] The present invention also relates to a steering wheel, which, for example, has a steering wheel hub, at least one steering wheel spoke, and a steering wheel rim supported by the steering wheel spoke. In one of the above embodiments, the steering wheel according to the invention also has a function display. Preferably, the function display is part of a control element fixed to the steering wheel. For example, the feet of the control element are fixed to the steering wheel rim in an anti-rotational manner. Preferably, the display surface of the function display is arranged between the steering wheel rim and the steering wheel hub or a bumper covering the steering wheel hub.

[0029] The invention and its technical context will now be explained in detail with reference to the accompanying drawings. It should be noted that the drawings illustrate particularly preferred embodiments of the invention, but this is not a limitation thereof. Attached Figure Description

[0030] The attached diagram schematically illustrates:

[0031] Figure 1 This is a schematic top view of an embodiment of the functional display 1 according to the present invention;

[0032] Figure 2 This is a schematic cross-sectional view of one embodiment of the control element 10 according to the present invention, which has another embodiment of the function display 1 according to the present invention;

[0033] Figure 3 This is a schematic cross-sectional view of another embodiment of the control element 10 according to the present invention, which has another embodiment of the function display according to the present invention 1;

[0034] Figure 4 This is a top view of an embodiment of the invention, which has a steering wheel 20 with two control elements 10 according to the invention. Detailed Implementation

[0035] Figure 1 The illustration schematically depicts an embodiment of the functional display 1 according to the invention, which is used to selectively display exactly one or multiple symbols simultaneously, the symbols representing switching functions and / or switching states, such as warning flashing symbols, etc. In particular, the turning on and off of the light source is understood as selective display.

[0036] The symbol 7 can be optically displayed to viewer B by selectively activating the backlight, or by turning off the backlight, making the symbol almost invisible to viewer B. Here, the two states of the light source should correspond to different on / off states, i.e., the functional states of the vehicle components. The symbol in... Figure 1The letters A and B are used to indicate this. According to the invention, the functional display 1 includes a light guide 2 made of a transparent or translucent material. The light guide 2 has a planar display portion 2a and multiple light input portions 2b, 2b', with two light input portions per light guide 2. Each light input portion 2b, 2b' is assigned one or more light sources 14, 14' through an adjacent arrangement. In the illustrated embodiment, each light input portion 2b, 2b' is precisely assigned one light source 14', and light L, L' enters the light guide 2, particularly the display portion 2a, via the respective associated light input portions 2b, 2b'. Here, from the viewer's perspective, the light entry occurs laterally, such as... Figure 1 As shown, Figure 1 The orientation of the functional display 1 is shown, which corresponds to the orientation of the functional display 1 in its normal installation position.

[0037] The flat panel display portion has two opposing main surfaces 8 and 9, wherein main surface 8 faces the viewer, such as a vehicle driver, in the conventional arrangement of the functional display 1 and is the display plane, while the other main surface 9 is arranged away from the viewer. The main surfaces 8 and 9 are understood to be those surfaces of the light guide 2 having the largest surface area. The main surfaces 8 and 9 are connected via end faces and form the narrow side of the display portion 2a. The light guide 2 is made, for example, of a transparent or translucent thermoplastic, wherein the display portion 2a is integrally connected to light input portions 2b and 2b', respectively configured as ring-shaped extensions. Except for the surface structures described below, the main surfaces 8 and 9 are designed to be substantially flat and smooth. According to the invention, at least one of the main surfaces 8 and 9 of the light guide 2, here the main surface 8 facing the viewer B, is partially surface-structured by introducing a plurality of microstructures into the main surface 8 that cause light refraction and / or light scattering, referred to as the surface-structured boundary surface regions 6a and 6b, and here denoted by symbols A and B respectively.

[0038] from Figure 1As can be seen, the light input portions 2b and 2b' are arranged such that when viewed from the light propagation direction, their extending directions do not intersect each other and are substantially parallel to each other. The surface-structured boundary surface regions 6a and 6b of the light guide 2 are arranged in such a staggered manner that each surface-structured boundary surface region 6a and 6b is directly adjacent to a light input portion 2b and 2b'. This prevents light from reaching other surface-structured boundary surface regions 6a and 6b of the same light guide 2, except for the corresponding associated surface-structured boundary surface regions 6a and 6b, from reaching the light input portions 2b and 2b'. Therefore, the light input portions 2b and 2b' and the surface-structured boundary surface regions 6a and 6b of the light guide 2 are arranged in such a way that light L and L' incident on the light input portions 2a and 2b' will not reach more than one surface-structured boundary surface region 6a and 6b without internal reflection within the light guide 2.

[0039] like Figure 1 As further shown, the light input portions 2b and 2b' of the light guide 2 each form a pair of opposing wings that converge into the display portion 2a. The envisioned tangential extension of these wings defines an envisioned partial volume in the display portion 2a. Within the envisioned partial volume, only one surface-structured boundary surface region is arranged, i.e., 6a is arranged in the envisioned extended partial volume of the light input portion 2b, and 6b is arranged in the envisioned extended partial volume of the light input portion 2b'.

[0040] Furthermore, the display portion 2a is coated in a manner that reduces reflection to obtain layer 5, which is often referred to as an anti-reflective coating or protective layer. It has the task of reducing, for example, the amount of light reflected into the light guide from the coated end face compared to the uncoated end face through light absorption in the coating. This can be applied comprehensively, except, for example, in the light incident area set for the light source in the light input portion.

[0041] Therefore, when each conductor 2 activates only the light source 14 or 14' associated with the light input portion 2b or 2b', the maximum optical density of the light radiation of exactly one surface-structured boundary surface region 6a or 6b is dominant relative to the remaining surface-structured boundary surface regions 6b or 6a, i.e., the brightest, while the corresponding maximum optical density of the remaining surface-structured boundary surface regions 6b or 6a is not greater than two percent of the maximum optical density of the dominant surface-structured boundary surface region 6a or 6b.

[0042] In the illustrated embodiment, the microstructure is understood as a single recess in the main surface 8, with a maximum size ranging from 1 to 999 μm, preferably from 1 to 25 μm. Preferably, the microstructures are uniformly spaced, but distributed only on the surface-structured boundary surface regions 6a, 6b of the main surface 8. Here, all microstructures are uniformly formed and have a consistent orientation, and are constructed such that they generate a collimated beam of light L or L' emitted from the light guide 2, the light originating from the light source 14 or 14' and entering the display portion 2a of the light guide 2 beforehand via the light input portion 2b or 2b'.

[0043] When the light sources 14 and 14' are activated respectively, the light L incident on the light guide 2 is emitted towards the viewer B due to light refraction and / or light scattering in the surface-structured boundary surface regions 6a and 6b, thereby making the symbols A and B generated and illuminated by the surface-structured boundary surface regions 6a or 6b visible to the viewer.

[0044] Surface structuring results in enhanced light emission towards the viewer, for example, compared to a flat and therefore unstructured design of the associated main surface 8. This can be explained as follows: because the microstructured light beams L, L' are struck at angles predetermined by the microstructure at angles that do not satisfy the condition of total internal reflection, the light beams L, L' leave the display portion 2a, 6b of the light guide 2 due to the microstructure at the boundary surface regions 6a or 6b of the surface structuring. The surface-structured boundary surface regions 6a, 6b will, for example, be displayed as an image, its reverse illustration, or its outline, frontally.

[0045] According to the invention, devices 3 and 4 are also provided for mutual light blocking between the light input portions 2b, 2b' and the light sources 14, 14'. These include devices designed such that light L' that has entered the light input portion 2b is unlikely to exit and enter the adjacent light input portion 2b', and vice versa. This is achieved, for example, by applying an opaque coating 3 to each surface of the light input portions 2a, 2b' facing the adjacent light input portions 2b', 2b. Furthermore, these devices 3 and 4 include a partition 4 that ensures that the light L, L' from the light sources 14, 14' is transmitted as far as possible only to the associated, adjacent light input portions 2b, 2b', while the surrounding, non-associated light input portions are blocked relative to the non-associated light sources. This is achieved here by multiple partition holes having openings respectively open to the associated light input portions 2b, 2b'. To prevent unwanted light propagation in the light guide 2, especially when affected by external light, the light guide 2 has an anti-reflective coating 5 on at least one end face, preferably on the end face facing away from the light sources 14, 14'. This coating is also commonly referred to as an anti-reflective coating or protective layer. It has the task of reducing, for example, the amount of light L, L′ reflected into the light guide 2 from the coated end face compared to the uncoated end face by absorbing light in the coating. This can be coated circumferentially, except for, for example, the light incident areas of the light input portions 2b, 2b' where the light sources 14, 14's light L, L′ are located. The anti-reflective coating 5 has, for example, an optical refractive index that is numerically between the refractive index of air and the refractive index of the material of the light guide 2.

[0046] Figure 2 An embodiment of the control element 10 of the present invention 10 is shown, which includes another embodiment of the functional display 1 according to the present invention, and this embodiment is similar to... Figure 1The difference in the implementation lies in the arrangement of a stack of light guides 2. The control element 10 has feet 19 for fixing the control element 1 to a vehicle component, such as a dashboard, a passenger compartment panel, or particularly a steering wheel rim 11 of a motor vehicle steering wheel. The control element 10 according to the invention also includes a control portion 20 defining a control surface 21, which is configured as a cantilever arm. The control portion 20 or the cantilever arm is mounted on the feet 19 by means of a solid joint 22 so that when an operating force is applied perpendicularly to the control surface 21, the control portion 20 can pivot about a contemplated pivot axis A defined by the solid joint 22 against the restoring force relative to the feet 3. The solid joint 22 is formed by an integral connection between the feet 3 and the control portion 2. The restoring force is generated, for example, substantially by deformation of the solid joint 22. A device 16 is also provided to detect the amount of pivoting between the control portion 20 and the feet 19, for example by means of a device with a contact sensing system, such as an electromechanical or resistive sensing device, or preferably a device with a non-contact sensing system, such as an optical, capacitive, or inductive sensing device. The control element 1 according to the invention is particularly suitable for designs in which, about a conceived pivot axis A, from Figure 2 The maximum pivoting amount from the unoperated static position to the pivoting position of the most feasible operation is less than 10°, preferably less than 5°.

[0047] According to the invention, an actuator 15, which receives an electrical control signal from an electronic control device (not shown), is also provided to generate active tactile feedback, also known as tactilely perceptible feedback, wherein the actuator 15 is preferably fixed only to the control unit 20. Preferably, the actuator 15 is an inertial-based, motor-based actuator, such as a motor with an eccentrically mounted mass fixed relative to its center of gravity on its rotating drive shaft, or a magnetic coil actuator, piezoelectric actuator, or linear broadband actuator, such as a voice-coil actuator or a linear resonant actuator. Preferably, the actuator 15 is fixed to the control unit 20 by force-locking or material-locking connections, such as by screw tightening or adhesive bonding. By fixing it only to the control unit 20, structural noise is prevented or at least minimized from coupling into the steering wheel rim 11 and thus into vehicle components.

[0048] The pivot detection device 16 is configured to sense the relative movement between the foot 19 and the control unit 20, preferably close, preferably non-contact sensing, such as capacitive, optical, and / or inductive detection. Due to the gapless support of the control unit 20 implemented by the solid-state connector 22, in conjunction with the (preferably non-contact) pivot detection device, low to no hysteresis detection of the operating force is achieved, which provides, for example, an output for triggering a switching function or control function, or at least an optically, acoustically, or tactilely perceptible output.

[0049] The control surface 21 is formed by a partially transparent partition 7, which provides the viewer B with a view of the display area of ​​the functional display 1 arranged below. The functional display 1 comprises a stack of multiple light guides 2, whose display portions 2a are constructed to be substantially transparent to ensure an unobstructed view of the control area, such as instruments on a dashboard, located below, through the display portions 2a of the functional display 1. The light guides 2 are each made of thermoplastic plastic, particularly thermoplastic film, and thermoplastic layers bonded to the plastic film material by reverse injection, and their display portions 2a are separated by air gaps 17 disposed between the display portions 2a of the light guides 2. The display portions 2a of the light guides 2 each form at least one main surface 8 facing the viewer, while the two upper display portions 2a of the light guides 2 closer to the viewer B each have a main surface 9 facing away from the viewer B, which faces the display portions 2a adjacent to each other in the stacking direction. Each light guide 2 corresponds to multiple light sources 14, namely multiple light-emitting diodes with SMD structure. These light sources are arranged such that the light generated by them is injected into the corresponding light guide 2 through the lateral, loop-shaped light input portion 2b of the light guide 2 relative to the stacking direction.

[0050] exist Figure 2 In the illustration, only one of the two light input portions 2b of each light guide 2 is visible, and only one associated adjacent light source 14 is visible. The number of light input portions 2b corresponds to the number of symbols that can be represented by the corresponding light guide 2. Similarly, the number of light sources 14 for each light guide 2 corresponds at least to the number of symbols that each light guide 2 can represent. In at least one main surface 8, 9 of the display portion 2a of the light guide 2, a surface-structured boundary surface region 6a, composed of multiple microstructures, is introduced by stamping. These surface-structured boundary surface regions ensure that light is emitted from the corresponding light guide 2 toward the viewer B. The surface-structured boundary surface region 6a is applied in the form of symbols that become visible to the viewer B when the associated light source 14 is activated. The microstructures are constructed in the same manner and have a diameter of 1 to 25 μm. The microstructures can be disposed in the main surface 8 facing the viewer B and / or the main surface 9 facing away from the viewer B.

[0051] The display portion 2a of the light guide 2 is transparent at least outside the surface-structured boundary surface region 6a, which represents only a portion of the respective main surfaces 8, 9. This ensures that most of the display portion 2a of all light guides 2 remains transparent, and guarantees visibility, for example, through the functional display 1, allowing the viewer B to focus on other displays or road routes via the functional display 1. This enables, for example, the placement of the control element 10 on the steering wheel, e.g., in the area between the steering wheel hub and the steering wheel rim, without obstructing the view on the dashboard. In the vertical projection of the surface-structured boundary surface region 6a of the light guide 2 (preferably all stacked light guides 2) onto the control surface 21, the projected surface-structured boundary surface regions 6a do not overlap, allowing different symbols to be clearly visible using the various light sources 14 of each light guide 2.

[0052] In order to avoid structuring boundary surface regions towards adjacent light guides 2 and other surfaces of the same light guide 2 (e.g., Figure 1 To prevent unwanted light scattering or radiation in the direction of the surface-structured boundary surface region (shown as 6b), devices 3 and 4 for light shielding are provided. These devices include a partition 4 and an opaque coating 3, the partition having a partition hole facing the light input portion 2b of the light guide 2, and the opaque coating being applied to the surface of the light input portion 2a, particularly the surface facing the adjacent light input portion 2b of the same light guide 2.

[0053] Figure 3Another embodiment of the control element 10 according to the invention is shown, which also includes another embodiment of the functional display 1 according to the invention. It differs substantially from the above-described embodiment in the design of the light input portion 2b and the placement of the light source 14. The control element 10 also has a foot 19 for securing the control element 1 to a vehicle component, such as a dashboard, a passenger compartment panel, or particularly the steering wheel rim 11 of a motor vehicle steering wheel. The control element 10 according to the invention also includes a control portion 20 defining a control surface 21, which is configured as a cantilever arm. The control portion 20 or the cantilever arm is mounted on the foot 19 by means of a solid joint 22 so that when an operating force is applied perpendicularly to the control surface 21, the control portion 20 can pivot about a contemplated pivot axis A defined by the solid joint 22 against the restoring force relative to the foot 3. The solid joint 22 is formed by an integral connection between the foot 3 and the control portion 2. The restoring force is generated, for example, substantially by deformation of the solid joint 22. An additional device 16 is provided to detect the pivoting amount between the control unit 20 and the foot 19. This detection can be achieved, for example, by means of a device with a contact sensing system, such as an electromechanical or resistive sensing device, or preferably a device with a non-contact sensing system, such as an optical, capacitive, or inductive sensing device. The control element 1 according to the invention is particularly suitable for designs in which the pivoting element rotates about a conceived pivot axis A from… Figure 2 The maximum pivoting amount from the unoperated static position to the pivoting position of the most feasible operation is less than 10°, preferably less than 5°.

[0054] According to the invention, an actuator 15, which receives an electrical control signal from an electronic control device (not shown), is also provided for generating active tactile feedback (also known as tactilely perceptible feedback), wherein the actuator 15 is preferably fixed only to the control unit 20. Preferably, the actuator 15 is an inertial-based, motor-based actuator, such as a motor with an eccentrically mounted mass fixed relative to its center of gravity on its rotating drive shaft, or a magnetic coil actuator, piezoelectric actuator, or linear broadband actuator, such as a voice-coil actuator or a linear resonant actuator. Preferably, the actuator 15 is fixed to the control unit 20 by force-locking or material-locking connections, for example by screwing or gluing. By fixing it only to the control unit 20, structural noise is prevented or at least minimized from coupling into the steering wheel rim 11 and thus into vehicle components.

[0055] The pivot detection device 16 is configured to detect relative movement between the detection foot 19 and the control unit 20, preferably in close proximity, preferably without contact, such as capacitive, optical, and / or inductively. Due to the gapless support of the control unit 20 implemented by the solid-state connector 22, in conjunction with the (preferably non-contact) pivot detection device 16, low to no hysteresis detection of the operating force is achieved, which provides, for example, an output for triggering a switching function or control function, or at least an optically, acoustically, or tactilely perceptible output.

[0056] The control surface 21 is composed of a partially transparent cover layer 7, which provides the viewer B with a view of the display area of ​​the functional display 1 arranged below. The functional display 1 comprises a stack of multiple light guides 2, whose display portions 2a are constructed substantially transparently to ensure an unobstructed view for the viewer B or operator through the display portions 2a of the functional display 1 to the control area below, such as instruments on a dashboard. The light guides 2 are each composed of thermoplastic plastic, particularly thermoplastic film, and thermoplastic layers bonded to the plastic film material by reverse injection, and their display portions 2a are separated by air gaps 17 disposed between the display portions 2a of the light guides 2. The display portions 2a of the light guides 2 each constitute at least one main surface 8 facing the viewer, while the two upper display portions 2a of the light guides 2 closer to the viewer B each have a main surface 9 facing away from the viewer B, which faces the display portions 2a adjacent to each other in the stacking direction. Each light guide 2 corresponds to multiple light sources 14, namely multiple light-emitting diodes with SMD structure. These light sources are arranged such that the light generated by them is injected into the corresponding light guide 2 through the lateral, loop-shaped light input portion 2b of the light guide 2 relative to the stacking direction.

[0057] exist Figure 3 In the illustration, each light guide 2 has only one light input portion 2b visible, and only one associated adjacent light source 14 visible. The number of light input portions 2b of each light guide 2 corresponds to the number of symbols that can be represented by the corresponding light guide 2. Similarly, the number of light sources 14 of each light guide 2 corresponds at least to the number of symbols that each light guide 2 can represent. In at least one main surface 8, 9 of the display portion 2a of the light guide 2, a surface-structured boundary surface region 6a, composed of multiple microstructures, is introduced by stamping. These surface-structured boundary surface regions ensure that light is emitted from the corresponding display portion 2a of the corresponding light guide 2 toward the viewer B. The surface-structured boundary surface region 6a is applied in the form of symbols that become visible to the viewer B when the associated light source 14 is activated. The microstructures are constructed in the same manner and have a diameter of 1 to 25 μm. The microstructures can be disposed in the main surface 8 facing the viewer B and / or the main surface 9 facing away from the viewer B.

[0058] The display portion 2a of the light guide 2 is transparent at least outside the surface-structured boundary surface region 6a, which represents only a portion of the corresponding main surfaces 8, 9. Thus, most of the display portion 2a of all light guides 2 remains transparent, ensuring visibility, for example, through the functional display 1, allowing the viewer B to focus on other displays or road routes through the functional display 1. This enables, for example, the placement of the control element 10 on the steering wheel, e.g., in the area between the steering wheel hub and the steering wheel rim, without obstructing the view on the dashboard. In the vertical projection of the surface-structured boundary surface region 6a of the light guide 2 (preferably all stacked light guides 2) onto the control surface 21, the projected surface-structured boundary surface regions 6a do not overlap, allowing different symbols to be clearly visible using the various light sources 14 of each light guide 2.

[0059] and Figure 2 In contrast to the embodiment shown, the light sources 14 are not only arranged laterally relative to the display portion 2a of the light guide 2 from the viewer B's perspective, but also positioned below the adjacent light input portion 2b from the viewer's perspective. These light sources each have an L-shaped curved cross-section. This embodiment results in all light input portions 2b having an incident surface facing the adjacent light source 14. Figure 2 The implementation differs in that the incident surface is not perpendicular to the main surfaces 8 and 9 of the display portion 2a of the light guide 2, but rather parallel to them. This is to avoid structuring boundary surface regions (e.g., towards adjacent light guides 2 and towards other surfaces of the same light guide 2) in this way. Figure 1 To prevent unwanted light scattering or radiation in the direction of the surface-structured boundary surface region (shown as 6b), a light-shielding device 3 is provided. This device includes an opaque coating 3 arranged such that it separates the light input portions 2b of the light guide 2 from each other and the light input portions 2b of different light guides 2 opaquely from each other. To obtain an inner reflective surface 18 for light redirection in each light input portion 2b, parts of the light input portion 2b are partially uncoated.

[0060] like Figure 4As shown, the present invention also relates to a steering wheel 20. The steering wheel 20 has a buffer covering the steering wheel hub, at least one steering wheel spoke, and a steering wheel rim 11 supported by the steering wheel spoke. The steering wheel 20 according to the invention also has two function displays 1, each of which is a component of a control element 10 fixed to the steering wheel 20 and integrated into a corresponding control unit, which is pivotally mounted on a foot of the control element 10. Here, the foot of the control element 10 is anti-rotatably fixed to the steering wheel rim 11. A generally transparent display surface of the function display 1 is disposed between the steering wheel rim 11 and the steering wheel hub or the buffer covering the steering wheel hub of the steering wheel 20. With selective activation of the light source belonging to the function display 1, depending on the selection, the surface-structured boundary surface areas 6a, 6b representing different symbols in the area of ​​the display surface of the function display 1 are visible to the viewer (i.e., the driver), while, due to the transparency of the function display 1, the instrument panel or gauges located behind the steering wheel 20 are visible to the driver in the remaining area.

Claims

1. A function display (1) for a motor vehicle, for selectively displaying a plurality of symbols representing corresponding switching functions and / or switching states, comprising: At least one light guide (2) made of a transparent or translucent material, wherein the light guide includes a planar display portion (2a) having two opposing main surfaces (8, 9), wherein the main surface (8) faces the viewer (B) as a display surface, while the other main surface (9) faces away from the viewer (B), and the light guide (2) also has at least two light input portions (2b). Multiple light sources (14, 14') have their light (L) entering the light guide (2) via one of the light input portions (2b, 2b') adjacent to the corresponding light source, and are further guided into the display portion (2a) in the lateral direction from the viewer's perspective (B). At least one main surface (8, 9) of the display portion (2a) of the light guide (2) is surface-structured by a plurality of microstructures introduced into the respective main surface (8) to cause light refraction and / or light scattering, so as to form at least two surface-structured boundary surface regions (6a, 6b) as sub-regions of the respective main surface (8, 9) in the light guide (2); the sub-regions are arranged staggered in the lateral direction from the viewer's (B) perspective and are respectively represented by symbols; When the light sources (14, 14′) are activated respectively, light (L, L′) entering the light guide (2) is emitted toward the viewer (B) due to light refraction and / or light scattering in the surface structured boundary surface regions (6a, 6b), making the corresponding displayed symbols visible to the viewer (B) due to backlighting. The light input portion (2b, 2b′) and the surface-structured boundary surface region (6a, 6b) of the light guide (2) are arranged such that light (L, L′) incident into the light input portion (2b, 2b′) can reach at most one surface-structured boundary surface region (6a, 6b) without internal reflection in the light guide (2).

2. The functional display according to claim 1, wherein, A device (3, 4) is provided for mutual light blocking of the light input section (2b, 2b′) and / or the light source (14, 14′).

3. The functional display (1) according to claim 2, wherein the means (3, 4) for mutually shielding light includes an opaque coating (3) on the respective light input portions (2b, 2b′).

4. The functional display (1) according to claim 2 or 3, wherein, The device (3, 4) for mutual shading includes at least one partition (4) having an open partition opening in the direction of the associated light input portion (2b, 2b').

5. The functional display (1) according to claim 1, wherein the light input portion (2b, 2b′) and the surface-structured boundary surface regions (6a, 6b) of the light guide (2) are arranged such that each surface-structured boundary surface region (6a, 6b) is opposite to a light input portion.

6. The functional display (1) according to claim 1, wherein, The light input portion (2b, 2b′) and the surface-structured boundary surface regions (6a, 6b) of the light guide (2) are arranged such that each surface-structured boundary surface region (6a, 6b) is adjacent to a light input portion.

7. The functional display (1) according to claim 1, wherein the light input portion (2b, 2b′) of the light guide (2) forms a pair of opposing wings that converge into the display portion (2a), wherein the contemplated tangential extension of the wings defines a contemplated partial volume in the display portion (2a), within which only a surface-structured boundary surface region (6a, 6b) is precisely arranged.

8. The functional display (1) according to claim 1, wherein the display portion (2a) is coated to reduce reflection.

9. The functional display (1) according to any one of claims 1 to 3, wherein when only one light source (14, 14') associated with the light input portion (2b, 2b') is activated in each light guide (2), exactly one maximum light density of the light radiation of exactly one surface-structured boundary surface region (6a, 6b) is dominant relative to the remaining surface-structured boundary surface regions (6a, 6b), i.e., the brightest, while the corresponding maximum light density of the remaining surface-structured boundary surface regions (6a, 6b) is determined simultaneously is no greater than two percent of the maximum light density of the dominant surface-structured boundary surface region (6a, 6b).

10. The functional display (1) according to claim 1, wherein the light input portion (2b, 2b') has an incident surface facing an adjacent light source (14, 14'), the incident surface being not perpendicular to the main surface (8, 9) of the display portion (2a) of the light guide (2).

11. The functional display (1) according to claim 10, wherein the incident surface is parallel to at least one main surface (8, 9) of the display portion (2a) of the light guide (2).

12. The functional display according to claim 1, wherein, from the viewer's (B) perspective, the light source (14) is respectively arranged below the adjacent light input portion (2b).

13. The functional display (1) according to claim 1, wherein the surface-structured boundary surface regions (6a, 6b) are generated by pressing and / or molding.

14. The functional display (1) according to any one of claims 1 to 3, wherein the surface-structured boundary surface regions (6a, 6b) of the display portion (2a) of the light guide (2) have uniformly formed three-dimensional microstructures with an average number density in the range of 400 to 7000 per square millimeter.

15. The functional display (1) according to claim 14, wherein the average number density of the three-dimensional microstructure is in the range of 400 to 4000 per square millimeter.

16. The functional display (1) according to claim 14 or 15, wherein the microstructures of the surface-structured boundary surface regions (6a, 6b) have a maximum size in the range of 1 to 50 µm.

17. The functional display (1) according to claim 14 or 15, wherein the microstructures of the surface-structured boundary surface regions (6a, 6b) have a maximum size in the range of 1 to 25 µm.

18. The functional display (1) according to claim 1, wherein the area of ​​all surface-structured boundary surface regions (6a, 6b) of the display portion (2a) of the light guide (2) is not greater than 0.5 for each light guide (2) on the corresponding main surface (8) of the display portion visible to the viewer.

19. The functional display (1) according to claim 1, wherein the area of ​​all surface-structured boundary surface regions (6a, 6b) of the display portion (2a) of the light guide (2) is no greater than 0.3% of the area of ​​each light guide (2) on the corresponding main surface (8) of the display portion visible to the viewer.

20. The functional display (1) according to any one of claims 1 to 3, wherein the functional display (1) comprises a plurality of light guides (2) arranged in a stacked manner.

21. The functional display (1) according to claim 1, wherein the display portion (2a) of the light guide (2) is transparent to the viewer (B) in the area outside the boundary surface region (6a, 6b) of the surface structured surface.

22. A control element (10) comprising a functional display (1) according to any one of claims 1-21 and a control unit (20) specifically for touch or operation, wherein, The functional display (1) is integrated into the control unit (20).

23. A steering wheel for a motor vehicle, comprising the control element (10) according to claim 22.

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