Function display for displaying a symbol representing a switching function and / or a switching state

Abstract

The invention relates to a functional display having a stack of light guides formed by at least two transparent or translucent planar light guides arranged overlapping in the stack direction, the light guides being spaced apart as transparent or translucent layers formed of a material that is optically thinner compared to the adjacent light guides, having a main face facing the observer and in at least one light guide a main face facing away from the observer facing the next adjacent light guide in the stack direction, respectively, at least one light source per light guide arranged to cause light to be incident into the respective light guide via an end face of the light guide, each light guide further being provided with a microstructured portion arranged in or on the light guide refracting and / or scattering light to produce a symbol display, each light guide forming at least one rim formed as abutting or located in the remaining end faces other than the end face having the light incident area, and further an opaque layer applied on the respective light guide covering the respective rim.

Description

Technical Field

[0001] This invention relates to a functional display for selectively displaying symbols representing switch functions and / or switch states. Background Technology

[0002] These functional displays are necessary, for example, in multi-functional operating elements, to visualize the switching functions and / or switching states associated with the operating element. Electronic pixel matrix displays are typically used for this purpose. However, they are relatively expensive, and their rectangular shape, in most cases, limits their configuration and placement. Furthermore, electronic pixel matrix displays often suffer from "burn-in" when displaying static content; that is, the displayed content remains undesirably visible even when the display is off due to visually perceptible damage to the display's imaging layer. Additionally, such electronic pixel matrix displays consume relatively high amounts of power. Moreover, in some applications, conventional electronic pixel matrix displays are prohibited due to the risk of injury, for example, in the event of a head collision. It is desirable to have essentially transparent functional displays so that the area below remains visible to the operator. For example, the line of sight towards the driveway surface or the portion of the functional display located behind it (especially the display located there) should remain visible to the driver. For this reason, a functional display formed of transparent plastic with multiple stacked light conductors is preferred, in which light is incident laterally and locally emitted, for example, through microstructured portions for scattering, in order to make the symbols visible. Given the optimal placement of such functional displays within the driver's field of vision, it is crucial to avoid light emanation from undesirable locations. This involves not only the light from the activated light source but also ambient or external light incident on the light conductor. It has been shown that the edges of the light conductor, in particular, are responsible for such undesirable light emanation or reflection, which are referred to herein as stray light. Summary of the Invention

[0003] Against this backdrop, the object of the present invention is to provide a functional display that can be manufactured inexpensively and reduces the risk of injury, which improves display quality and, in particular, reduces the danger of erroneous information caused by unwanted light emission or reflection. This object is achieved by the functional display according to claim 1. Correspondingly advantageous operating elements and methods relating to the manufacture of said functional display are the subject of the co-main claims. Advantageous designs are the subject of the dependent claims. It should be noted that the features individually detailed in the claims can be combined with each other in any technically meaningful manner and demonstrate other embodiments of the invention. The description, in particular, is supplemented with and describes the invention in detail in conjunction with the drawings.

[0004] This invention relates to a functional display, particularly for motor vehicles, for selectively displaying symbols representing switching functions and / or switching states. Selective display is understood as the ability to selectively display different symbols from a plurality of pre-given symbols, which in the solution of this invention is achieved by selectively selecting one or more light sources from a plurality of light sources and energizing them.

[0005] According to the present invention, the functional display includes a stack of light conductors formed by at least two transparent or semi-transparent planar light conductors arranged overlapping in a stacking direction. The light conductors are separated from each other by transparent or semi-transparent layers formed of a material that is optically thinner than the material of adjacent light conductors. An air gap is preferably provided between the light conductors. When the functional display is arranged in a predetermined manner, each light conductor has at least one main surface facing the observer, which serves as a display surface, wherein at at least one light conductor, the main surface facing away from the observer faces the next adjacent light conductor in the stacking direction. The light conductors are formed, for example, of plastics, preferably thermoplastics, such as polyethylene (PE), polycarbonate (PC), polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), acrylonitrile-butadiene-styrene (ABS), or polymethyl methacrylate (PMMA).

[0006] According to the invention, each light conductor is provided with at least one light source, which is arranged such that light enters the corresponding light conductor through a light incident region disposed at one of the end faces of the light conductor. The light source is, for example, a light-emitting diode (LED), particularly an SMD (Surface Mount Device) LED. To improve light incidence and / or to adapt the light radiation characteristics of the light source to the end face determined for allowing light to enter the light conductor, a lens and / or baffle are arranged, for example, between the light conductor and the light source. The baffle is also, for example, formed to suppress light leakage into other light conductors besides the assigned light conductor.

[0007] The functional display according to the invention optionally includes a transparent or translucent outer cover layer, which forms the observer-facing outer surface of the functional display when the functional display is arranged in a predetermined manner. The cover layer is, for example, a cover layer made of plastic, preferably thermoplastic, such as polyethylene (PE), polycarbonate (PC), polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), acrylonitrile-butadiene-styrene (ABS), or polymethyl methacrylate (PMMA), or a glass material, and is arranged to be spaced apart from the optical conductor stack via an air gap or a layer formed of an optically thinner material.

[0008] According to the present invention, each photoconductor is further provided with a microstructured portion for refracted and / or scattered light disposed in or on the photoconductor. The microstructured portion is configured to display a backlighting symbol in a visible manner to an observer by means of light incident on the photoconductor when the light source is activated. The microstructured portion causes light to be emitted in the direction of the observer through light refraction and / or light scattering. For example, the corresponding microstructure of the microstructured portion achieves an incident angle of light on the principal surface facing the observer, which does not satisfy the total internal reflection condition of the principal surface as an interface.

[0009] By selectively activating the light source, different on / off states or switching functions can be visualized relatively easily. Functional displays can be implemented simply and inexpensively, offering designers considerable design flexibility, which also involves the placement of the displays. Functional displays exhibit minimal aging effects from light radiation and are relatively energy-efficient. Microstructuring, for example, involves using symbols in relief as images, as their opposite illustrations, or as outline representations.

[0010] For example, the previously mentioned microstructured portion is formed by multiple uniformly spaced microstructures of the same shape, wherein the microstructured portion constitutes only a part of the display surface for each photoconductor, i.e., the so-called microstructured region. For example, the number density of microstructures in the microstructured region is 1,000 to 2,000 per mm. 2 For example, the microstructures each have a maximum diameter ranging from 1 to 25 μm. The microstructured portions can be introduced into the corresponding photoconductor via laser ablation, for example, by applying it in a three-dimensional manner through vitrographie (also known as laser internal engraving) or by applying it to one of its main surfaces. Preferably, the microstructured portions are formed in one of the main surfaces of each photoconductor by imprinting, for example, during the manufacture of the photoconductor by injection molding or by subsequent imprinting, thereby enabling the cost-effective realization of a functional display.

[0011] To save on structural height, for example, at least two directly adjacent optical conductors are provided, with their microstructured portions only located on the main surfaces that are opposite to each other, wherein the microstructured regions are arranged from stacked optical conductors to optical conductors that are staggered from each other.

[0012] The functional display is configured such that, except for the microstructured areas, it is transparent in most of the stacked display surfaces, thus ensuring transparency through the display and allowing an observer to trace other displays, instruments, or road directions. Consequently, the functional display can be placed, for example, at the steering wheel, in the area between the steering wheel hub and rim, without obstructing the view of the instrument panel.

[0013] According to the invention, each optical conductor in the optical conductor stack has at least one, preferably multiple, edges arranged in or adjacent to one of a plurality of end faces of the optical conductor that is not used for light incidence via the light incident surface (referred to as the remaining end faces). The optical conductor, for example, has two opposing, preferably parallel, main faces connected via end faces, for example at the narrow side and the long side of the optical conductor, the end faces forming a common edge together with the main faces of the optical conductor. The end faces extend substantially orthogonally to at least one or both main faces of the optical conductor.

[0014] According to the invention, an opaque and therefore light-blocking layer is also provided to cover the edges in question. This prevents unwanted light escaping from the edges, i.e., stray light. This includes light generated by a light source, as well as external light, such as ambient light, incident on the light conductor and striking the edges in question after propagation within the light conductor. Covering the edges achieves the desired goal of having only light escaping from the microstructured area when the light source is activated, and further approximates a "disappearance" effect when the light source is off. Opaquely covering the corresponding edges prevents unwanted light escaping, which prevents misinformation on the observer's side, or at least prevents stimulation on the observer's side.

[0015] Preferably, the opaque layer is applied in such a way that it surrounds the corresponding light conductor along the remaining end face of the light conductor while simultaneously exposing the display surface of the main surface, so as to facilitate particularly efficient isolation of the light conductor.

[0016] Preferably, at the edge covered by the opaque layer, one of the main faces and one of the remaining end faces of the corresponding optical conductor are adjacent to each other.

[0017] According to a preferred embodiment, the opaque layer extends from the remaining end face on both sides via the respective edges and via the respective adjacent main faces of the respective light conductors to the display surface of the light conductor, thereby holding the edges of the respective light conductors forming the remaining end face.

[0018] To achieve better edge wetting, according to a preferred embodiment, the remaining end faces of each photoconductor are convex. The edges may also be rounded.

[0019] Preferably, the light conductor and the opaque layer are connected in a material-compatible manner. This is achieved, for example, by manufacturing the light conductor together with the opaque layer connected thereto as a preform in a two-component injection molding process.

[0020] Preferably, the photoconductor and the opaque layer are formed of thermoplastics, such as polyethylene (PE), polycarbonate (PC), polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), acrylonitrile-butadiene-styrene (ABS), or polymethyl methacrylate (PMMA). More preferably, the opaque layer is formed of a thermoplastic elastomer.

[0021] According to an optional, preferred design, the opaque layer is a printed layer or an enamel layer. In one embodiment of the manufacturing method of the invention, the optical conductor is printed, for example, using a 3D digital printing method or a nozzleless digital printing method, to apply the opaque layer. According to another embodiment, the optical conductor is coated with an enamel that forms the opaque layer by spraying. Preferably, a removable and / or detachable masking layer is applied to the optical conductor before printing or spraying, wherein the areas provided for the opaque layer, especially the edges, remain uncovered. The optical conductor is then coated with the enamel that forms the opaque layer, covering the entire surface and, where appropriate, all sides, and the masking layer is subsequently removed, such that the opaque layer remains only in the areas provided for the opaque layer on at least one edge of the optical conductor.

[0022] The present invention also relates to an operating element having a functional display formed in one of the previously described embodiments. The operating element, for example, has a leg for securing the operating element to a vehicle component such as a dashboard, a passenger compartment liner, or, in particular, a steering wheel of a motor vehicle. The operating element of the present invention also has, for example, an operating member defining an operating surface, which is formed as at least one self-supporting lever arm. The self-supporting lever arm is supported on one side by means of a solid hinge at the leg, so that under an operating force acting perpendicular to the operating surface, the operating member can pivot relative to the leg about an imaginary pivot axis against a restoring force. For example, a device is also provided to detect the degree of pivoting between the operating member and the leg. Generally, the following region of the member is referred to as the solid hinge: this region allows pivoting between two rigid body regions by bending. The solid hinge provides gapless and thus noiseless support of the operating member at the leg. The legs and operating components are formed, for example, of thermoplastics such as polyethylene (PE), polycarbonate (PC), polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), acrylonitrile-butadiene-styrene (ABS), or polymethyl methacrylate (PMMA). The operating element of the present invention is particularly suitable for embodiments in which the maximum pivoting degree from an unacted rest position about an imaginary pivot axis to the actuated maximum pivoting position is less than 10°, preferably less than 5°.

[0023] Preferably, the function display is arranged below the translucent or transparent portion of the operating surface of the operating component of the operating element that is to be operated by touch or actuation.

[0024] For example, the operating element is arranged at the 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. The support leg of the operating element is, for example, fixed to the steering wheel rim in an anti-rotational manner. The display surface of the function display is preferably arranged between the steering wheel rim and the steering wheel hub or a buffer covering the steering wheel hub. Attached Figure Description

[0025] The invention and its technical environment will now be explained in detail with the aid of the accompanying drawings. It should be noted that the drawings illustrate particularly preferred embodiments of the invention; however, the invention is not limited to these embodiments. The drawings schematically illustrate:

[0026] Figure 1 A schematic cross-sectional view of an embodiment of the present invention is shown through the functional display 1;

[0027] Figure 2 A schematic cross-sectional view of an embodiment of the present invention, showing an operating element 10 with a functional display according to a second embodiment of the present invention;

[0028] Figure 3 The function display 1 is shown in Figure 1 A perspective view of the optical conductor 14 in the embodiment shown;

[0029] Figure 4 A cross-sectional view of the optical conductor 4 in a third embodiment of the functional display 1 is shown;

[0030] Figures 5a-5c An embodiment of the present invention manufacturing method for an optical conductor according to a fourth embodiment of a functional display 1 is shown;

[0031] Figure 6 A cross-sectional view of the optical conductor 4 of the fifth embodiment of the functional display 1 is shown. Detailed Implementation

[0032] Figure 1 The illustration schematically depicts a functional display 1 according to an embodiment of the invention. The functional display 1 according to the invention optionally includes a transparent or translucent outer cover layer 23. When the functional display 1 is arranged in a predetermined manner, the cover layer defines a surface 8 facing the observer B, and through the cover layer, the superimposed display surface 30 of a plurality of stacked light conductors 13, 14 is visible. The cover layer is, for example, 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 a cover layer formed of glass material.

[0033] According to the present invention, the functional display 1 further includes a stack of light conductors formed by at least two transparent or translucent planar light conductors 13 and 14, respectively formed of thermoplastic plastic layers and arranged in an overlapping manner. The light conductors 13 and 14 are separated by an air gap 24 disposed between them. The light conductors 13 and 14 respectively form a main surface H facing the observer B and a main surface H' facing away from the observer B, while the upper light conductor 13 closer to the observer B has a main surface H' facing away from the observer B and towards the next adjacent light conductor 14 in the stacking direction. The light conductors 13 and 14 are each labeled with at least one light source 12, i.e., one or more light-emitting diodes in the form of an SMD structure, the light source being arranged such that light generated therefrom is incident on the labeled light conductors 13 and 14 via a light incident area 31 on an end face S laterally relative to the stacking direction. The remaining end face S', which is not configured for light incident, therefore does not have a light incident area. To prevent unwanted light scattering or radiation from entering adjacent photoconductors 13 and 14 during light incidence, baffles 17 are provided. An opaque layer 25 is applied to the remaining end face S' opposite to the light source 12, such that not only are the edges K of the corresponding photoconductors 13 and 14 covered, but the remaining end face S' is also completely covered. This opaque layer 25 extends from the remaining end face S' on both sides, through the corresponding edges K, and through the respective adjacent main surfaces H and H' of the corresponding photoconductors 13 and 14, to the display surface 30 of the photoconductors, thus holding the corresponding edges of the photoconductors 13 and 14. Figure 1 As can be seen from this, this involves the edges K adjacent to one of the main faces H and H' and the other end faces S', but as... Figure 3 As shown, on the other hand, it also involves the edges K of the two remaining end faces S' that are adjacent to each other, because the opaque layer 25 is applied in such a way that it surrounds the respective light conductors 13, 14 along the remaining end faces S' of the respective light conductors and simultaneously exposes the display surface 30 of the main surfaces H, H'.

[0034] As from Figure 1 and Figure 3As can be seen, microstructured portions 16, formed by multiple microstructures, are introduced by imprinting into at least one of the main surfaces H and H' of the photoconductors 13 and 14, causing light to be emitted from the respective photoconductors 13 and 14 toward the observer B. The microstructures are arranged in the same shape and at uniform intervals, forming a continuous microstructured region 32 for each photoconductor 13 and 14, the outline of which corresponds to the shape of the symbol that becomes visible to the observer B when the corresponding light source 12 is activated. The microstructures 16 of the microstructured portions are formed to be of the same shape and have a diameter in the range of 1 to 25 μm. To save on construction height, microstructures 16 are provided in the main surfaces H and H' facing each other at the two directly adjacent photoconductors 13 and 14.

[0035] All photoconductors 13 and 14 are transparent outside the microstructured regions, ensuring that most of the display surface 30 remains transparent and, for example, allows for visibility through the functional display 1, enabling observer B to trace other displays or road directions through the functional display. Thus, the functional display 1 can be placed, for example, at the steering wheel, in the area between the steering wheel hub and rim, without obstructing the view of the dashboard. When the stacked display surface 30 is viewed vertically, the microstructured regions 32 of the photoconductors 13 and 14 do not overlap, so as not to affect the display quality of the symbols.

[0036] Figure 2 An embodiment of the operating element 10 of the present invention is shown, in which the functional display 1 of the present invention in the second embodiment is integrated. This operating element 10 has legs 3 for securing the operating element 10 to vehicle components such as dashboards, passenger compartment linings, or, in particular, the steering wheel rim 11 of a motor vehicle steering wheel. The operating element 10 of the present invention also has an operating member 2 defining an operating surface 9, said operating member being formed as at least one self-supporting lever arm. The self-supporting lever arm is supported on one side by means of a solid hinge 4 on the legs 3 so that, under an actuating force acting perpendicular to the operating surface 9, the operating member 2 can pivot relative to the legs 3 about an imaginary pivot axis A against a restoring force. The restoring force is generated, for example, by deformation of the solid hinge 4.

[0037] The invention also includes a device 6 for detecting the degree of pivoting between the operating member 2 and the support leg 3. The solid hinge 4 is formed solely through an integral connection between the support leg 3 and the operating member 2. The operating element 10 of the invention is particularly suitable for designs in which... Figure 2 The maximum pivot angle from the unacted rest position shown to the imaginary pivot axis A to the maximum possible actuated pivot position is less than 10°, preferably less than 5°.

[0038] According to the invention, an actuator 5 is also provided, which can be loaded by a control electronic device (not shown) with a control electrical signal to generate active tactile feedback (also referred to as tactilely perceptible output), wherein the actuator 5 is preferably fixed only at the operating component 2. The actuator 5 is preferably an inertial-based, motor-based actuator, such as a motor or magnet coil actuator, or piezoelectric actuator, or linear broadband actuator such as a voice-coil actuator or linear resonant actuator, with a mass body mounted eccentrically relative to its center of gravity fixed on its rotating drive shaft. The actuator 5 is preferably fixed at the operating component 2 by force-fit or material-fit connection, for example by screwing or bonding. Because it is fixed only at the operating component 2, structural noise input to the steering wheel rim 11 and thus to vehicle components is prevented, or at least minimized.

[0039] The pivot detection device 6 is configured to detect the relative movement, preferably proximity, between the leg 3 and the operating member 2 in a capacitive, optical, and / or inductive manner. Due to the cooperation between the gapless support of the operating member 2, achieved by the solid hinge 4, and the preferably non-contact pivot detection device 6, low to no hysteresis detection of the actuation force is achieved. This actuation force is configured, for example, to trigger a switching function or a control function, or at least an output that can be perceived optically, acoustically, or tactilely.

[0040] Beneath the operating surface 9 provided by the surface of the transparent cover layer 23, the stacked display surface 30 of the light conductors 13, 14, and 15 of the functional display 1 is visible. The functional display 1 is also formed to be substantially transparent so as to ensure that the observer B or the operator can view the operating area below it, such as the instruments on the dashboard, without obstruction.

[0041] Figure 2A second embodiment of the functional display 1 according to the present invention includes a stack of light conductors formed by three transparent or translucent planar light conductors 13, 14, and 15, respectively, made of thermoplastic and arranged in an overlapping manner. The light conductors 13, 14, and 15 are separated by air gaps 24 disposed between them. Each of the light conductors 13, 14, and 15 forms at least one main surface H facing an observer B, while the two upper light conductors 13 and 14 closer to the observer B each have a main surface H' facing away from the observer and towards the next adjacent light conductor 14 or 15 in the stacking direction. Each of the light conductors 13, 14, and 15 is labeled with at least one light source 12, i.e., a light-emitting diode in the form of an SMD structure, the light source being arranged such that the light generated therefrom is incident on the labeled light conductor 13, 14, and 15 via an end face laterally relative to the stacking direction. Baffles 17 are provided to prevent unwanted light scattering or radiation from entering adjacent light conductors 13, 14, and 15. An opaque layer 25 is applied to the remaining end faces S' opposite to the light source 12, such that not only are the edges K of the corresponding light conductors 13, 14, and 15 covered, but the remaining end faces S' are also completely covered. Here, the opaque layer 25 extends from the remaining end faces S' on both sides via the corresponding edges K and via the respective adjacent main surfaces H and H' of the corresponding light conductors 13, 14, and 15 to the display surface 30 of the light conductors. This relates to the edge K adjacent to one of the main surfaces H and H' and the remaining end faces S', and also to the edge K adjacent to the two remaining end faces S', because the opaque layer 25 is applied in such a way that it surrounds the corresponding light conductors 13, 14, and 15 along the remaining end faces S' of the corresponding light conductors while simultaneously exposing the display surface 30 of the main surfaces H and H'. However, this cannot be achieved in this case... Figure 2 As seen in the cross-sectional view.

[0042] Microstructured portions 16, formed of multiple microstructures, are imprinted into at least one of the main surfaces H and H' of photoconductors 13, 14, and 15, causing light to be emitted from the respective photoconductors 13, 14, and 15 toward observer B. The microstructures are identical in shape and uniformly spaced, forming a continuous microstructured region for each photoconductor 13, 14, and 15, the outline of which corresponds to the shape of a symbol that becomes visible to observer B when the corresponding light source 12 is activated. The microstructures 16 of the microstructured portions are formed to be identical in shape and have a diameter ranging from 1 to 25 μm.

[0043] All photoconductors 13, 14, and 15 are transparent outside the microstructured areas, ensuring that most of the display surface 30 remains transparent and, for example, allows for visibility through the functional display 1, giving observer B the possibility of tracking other displays or road directions through the functional display. Thus, the functional display 1 can be placed, for example, at the steering wheel, in the area between the steering wheel hub and rim, without obstructing the view of the instrument panel.

[0044] Figure 4 Another embodiment of the light conductor 14 is shown, as exemplarily used for all light conductors in the third embodiment of the functional display 1. In this embodiment, the light conductor 14 and the opaque layer 25 are respectively material-fitted together. This is achieved by manufacturing the light conductor 14, as an exemplary example of all light conductors used in the third embodiment, together with the opaque layer 25 attached thereto, as a preform in a two-component injection molding process. Formed by a corresponding mold, the light conductor 14 has a plurality of protrusions 34 in its main surface H' as spacing retainers, which, when arranged in the stack of light conductors of the functional display 1, abut against the next adjacent light conductor and provide a spacing relative to this light conductor to form an air gap. The light conductor 14 is formed of a thermoplastic, such as polyethylene (PE), polycarbonate (PC), polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), acrylonitrile-butadiene-styrene (ABS), or polymethyl methacrylate (PMMA), while the opaque layer 25 is formed of a thermoplastic elastomer.

[0045] Figures 5a to 5c A multi-step manufacturing method for a fourth embodiment of a functional display 1 is exemplarily shown for the light conductor 14. First, a removable and / or detachable masking layer 33 is applied to the light conductor 14, exposing the area of ​​the light conductor 14 to be coated with the opaque layer 24, particularly at least one edge K. Subsequently, the light conductor 14 is coated with an enamel forming the opaque layer 25 by printing or spraying, covering the entire surface and, where appropriate, all sides. The masking layer 33 is then removed, leaving the opaque layer 25 remaining only in the area where the opaque layer is provided on at least one edge K of the light conductor 14.

[0046] Figure 6 An exemplary photoconductor 14 is shown, which is exemplary for all photoconductors in the fifth embodiment of the functional display 1 of the present invention. Here, an opaque layer 25 is applied to the photoconductor 14, which is manufactured from thermoplastic by injection molding, using a 3D printing method.

Claims

1. A function display (1) for a motor vehicle for selectively displaying symbols (18) representing switch functions and / or switch states, the function display having: A stack of light conductors is formed by at least two transparent or translucent planar light conductors (13, 14, 15) arranged overlapping in a stacking direction. The light conductors are arranged with a transparent or translucent layer formed of a material that is optically thinner than the adjacent light conductors, such that the light conductors (13, 14, 15) each have a main face (H) facing the observer (B) as a display surface and in at least one light conductor (13, 14, 15) the main face (H') facing away from the observer (B) faces the next adjacent light conductor (13, 14, 15) in the stacking direction. At least one light source (12) for each optical conductor (13, 14, 15), the light source being arranged such that light is incident into the respective optical conductor (13, 14, 15) via a light incident area (31) arranged at one of the end faces (S, S') of the respective optical conductor (13, 14, 15). A transparent or translucent outer covering (23) forms a surface (8) facing the observer (B); Each of the photoconductor stacks (13, 14, 15) has a microstructured portion (16) for refracted and / or scattered light disposed in or on the photoconductor (13, 14, 15), the microstructured portion being formed to display a backlight illumination symbol (18) visible to the observer (B) through the covering layer (23) by means of light incident on the photoconductor (13, 14, 15) when the light source (12) is activated; and each photoconductor (13, 14, 15) forms at least An edge (K) is formed to be adjacent to or located in the remaining end face (S') except for the end face (S) having the light incident area (31); and an opaque layer (25) is applied to the respective light conductors (13, 14, 15) covering the respective edge (K), wherein the opaque layer (25) extends on both sides from the remaining end face (S') via the respective edge (K) and via the respective adjacent main faces (H, H') of the respective light conductors (13, 14, 15) to the display surface (30) of the light conductor.

2. The functional display (1) according to claim 1, wherein the opaque layer (25) is applied in such a way that it surrounds the corresponding light conductor (13, 14, 15) along the remaining end face (S') of the corresponding light conductor and exposes the display surface (30) of the main surface (H, H').

3. The functional display (1) according to any one of the preceding claims, wherein at the edge (K) covered by the opaque layer (25), one of the main surfaces (H, H') and one of the remaining end surfaces (S') are respectively adjacent to each other.

4. The functional display (1) according to claim 1, wherein the remaining end faces (S') of each optical conductor (13, 14, 15) are convex.

5. The functional display (1) according to claim 1, wherein the photoconductors (13, 14, 15) and the opaque layer (25) are respectively connected in a material-fitting manner.

6. The functional display (1) according to claim 1, wherein the optical conductor (13, 14, 15) and the opaque layer (25) are respectively formed of thermoplastic.

7. The functional display (1) according to the preceding claim, wherein the opaque layer (25) is formed of a thermoplastic elastomer.

8. The functional display (1) according to claim 1, wherein the opaque layer (25) is a printed layer or a paint layer.

9. The functional display (1) according to claim 1, wherein the photoconductors (13, 14, 15) are spaced apart by air gaps (24).

10. An operating element (10) for a steering wheel of a motor vehicle, said operating element having a function display (1) according to any one of the preceding claims.

11. The operating element (10) according to the preceding claim, wherein the function display (1) is arranged below the translucent or transparent portion of the operating surface (9) of the operating component (2) to be operated by touch or actuation of the operating element (10).

12. A method for manufacturing a functional display (1) according to any one of claims 1 to 9, wherein each of the photoconductor stacks (13, 14, 15) is manufactured from thermoplastic in an injection molding step, and the microstructured portion (16) is introduced into the respective photoconductor (13, 14, 15) in the injection molding step or in a subsequent imprinting method.

13. The method of claim 12, wherein each optical conductor (13, 14, 15) coated with the opaque layer (25) is manufactured in the two-component injection molding step.

14. The method of claim 12, wherein each photoconductor (13, 14, 15) is printed or sprayed to form the opaque layer (25).

15. The method according to claim 14, wherein each photoconductor (13, 14, 15) is first coated with a masking layer (33) before the printing coating or spraying, and the masking layer (33) is removed after the printing coating or spraying.

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