DE102021210914A1 - SIMPLE HOLOGRAPHIC LIGHT GUIDE - Google Patents

Abstract

In one aspect, the invention relates to a light guide structure for lighting, detection and/or holographic representation with at least one flat light guide for conducting electromagnetic radiation of at least one first spectrum, at least one lighting arrangement arranged on the first side surface of the light guide, at least one holographic decoupling structure for coupling out electromagnetic radiation guided in the light guide structure. The light radiated in by the lighting arrangement can have a large angular spectrum, with the holographic decoupling structure having a small angular spectrum. The invention also relates to a manufacturing method for such a light guide structure and a control element comprising a light guide structure.

Description

In one aspect, the invention relates to a light guide structure for lighting, detection and/or holographic representation with at least one flat light guide for conducting electromagnetic radiation of at least one first spectrum, at least one lighting arrangement arranged on the first side surface of the light guide, at least one holographic decoupling structure for coupling out electromagnetic radiation guided in the light guide structure. The light radiated in by the lighting arrangement can have a large angular spectrum, with the holographic decoupling structure having a small angular spectrum.

The invention also relates to a manufacturing method for such a light guide structure and an operating element comprising a light guide structure.

Background and state of the art:

The first holographic lighting concepts are already known in the prior art, for example from DE 10 2016 117 969 A1 .

Surprisingly, however, holographic elements can also be used in hitherto unknown areas of application within a vehicle and thus increase safety and operability.

A disadvantage of the previously known holographic lighting concepts lies in the complex lighting of the holographic structures, which is required to ensure a sufficient quality of the desired holographic lighting function. Up to now, this has primarily required that the frequency spectrum and angular spectrum of the light source are sufficiently matched to the hologram to be illuminated, for which purpose high-quality and expensive light sources and complex beam-shaping components often have to be used. The production is therefore often expensive. The coupling efficiency of the light source and the hologram is also different from the above. sizes dependent. As a result, holographic solutions have often been too expensive to mass produce.

On the other hand, classic illuminated displays and control elements, which do not require holographic elements, often reach their limits in terms of usability and safety. New functionalities can no longer be developed using the classic concepts.

Object of the invention:

It is an object of the invention to provide a device without the disadvantages of the prior art. In particular, it is an object of the invention to provide a simple and inexpensive holographic light guide and an inexpensive manufacturing method. It is a further object of the invention to provide a particularly user-friendly and secure holographic operating element which is at the same time robust and inexpensive and suitable for mass production.

Summary of the invention:

The object is solved by the features of the independent claims. Preferred embodiments of the invention are described in the dependent claims.

In a first aspect, the invention relates to a light guide structure for illumination, detection and/or holographic display, comprising at least one flat light guide, which is set up for conducting electromagnetic radiation of at least one first spectrum, at least one arranged on the first side surface of the light guide Lighting arrangement comprising at least one light source for emitting electromagnetic radiation with a first spectrum for irradiating electromagnetic radiation with the first spectrum into the light guide, at least one holographic decoupling structure, preferably spaced apart from the first side surface, which is set up for decoupling electromagnetic radiation guided in the light guide structure Radiation, preferably of the first spectrum, of the lighting arrangement within an acceptance angle spectrum of the decoupling structure from a first main surface of the light guide structure, where in which the illumination arrangement does not include a beam-shaping component and in which the acceptance angle spectrum of the holographic element is preferably at most 10°, particularly preferably at most 5°.

Such a light guide is particularly easy and inexpensive to produce.

The at least one holographic decoupling structure is preferably set up for a holographic display by generating a real and/or virtual image inside and/or outside the light guide structure and in particular inside the first main area of the light guide structure. The generation of an image within the first main area is preferably also referred to as an “in-plane” representation.

In particular, by using an acceptance angle spectrum that is limited as described and/or an "in-plane" representation, the requirements for the beam homogeneity (e.g. collimation, angle spectrum) of the electromagnetic radiation radiated in are low and, despite a simple structure, one can meet the requirements for quality and/or or brightness corresponding image display can be realized. A good compromise between quality and brightness can be found with an acceptance angle spectrum of no more than 10° in combination with an in-plane hologram, since the demands on the lighting are low with an in-plane hologram due to the lack of “depth” of the display. With an acceptance angle spectrum of at most 5°, the quality of the display can advantageously be improved. A sufficient number of light sources and/or a sufficiently strong light source can be used for any adjustment of the brightness.

It can also be preferred, especially in combination with an "in-plane" display, that the acceptance angle spectrum of the decoupling structure is at least 1°, more preferably at least 2°, even more preferably at least 3°, especially preferably at least 4° and in particular at least 5° amounts to. Since the lighting quality requirements for an acceptable display are particularly low with the "in-plane" display, the acceptance angle spectrum can advantageously be as large as possible in order to implement a simple construction of the light guide structure without beam-shaping components, which provides a good display quality with high efficiency and/or brightness connects.

In a further preferred embodiment of the invention, more than one holographic decoupling structure is included, in particular up to five holographic decoupling structures are included, each holographic decoupling structure having a different reconstruction angle within the angular spectrum of the light emitted by the lighting arrangement and / or emitted by the light source in the direction of the light guide has electromagnetic radiation.

The individual holographic decoupling structures and their combination can preferably have any of the properties described in this document, e.g. B. in relation to the acceptance angle spectrum.

Each holographic decoupling structure is preferably set up for a mutually matching holographic representation by generating a mutually matching real and/or virtual image inside and/or outside the light guide structure and in particular inside the first main surface of the light guide structure.

In this way, the efficiency of the light guide structure can advantageously be increased while the display quality remains the same.

In a second aspect, the invention relates to a light guide structure for illumination, detection and/or holographic display, comprising at least one flat light guide, which is set up for conducting electromagnetic radiation of at least one first spectrum, at least one arranged on the first side surface of the light guide Lighting arrangement comprising at least one light source for emitting electromagnetic radiation with a first spectrum for irradiating electromagnetic radiation with the first spectrum into the light guide, at least one holographic decoupling structure, preferably spaced apart from the first side surface, which is set up for decoupling electromagnetic radiation guided in the light guide structure Radiation, preferably of the first spectrum, of the lighting arrangement within an acceptance angle spectrum of the decoupling structure from a first main surface of the light guide structure, w preferably the angular spectrum of the electromagnetic radiation radiated in by the lighting arrangement and/or emitted by the light source in the direction of the light guide is at least 15°, preferably at least 20°, more preferably at least 30° and in particular at least 40°, and the Lighting arrangement for the holographic decoupling structure conducted angle spectrum of the radiated electromagnetic radiation and / or the acceptance angle spectrum of the holographic element is a maximum of 5 ° in terms of amount.

It is obvious to a person skilled in the art that advantages, definitions and embodiments of the device according to the invention according to the first aspect also apply to the claimed device according to the invention according to the second aspect and vice versa.

A light guide structure for illumination, detection and/or holographic representation preferably comprises at least one element that is transparent to the light to be guided, e.g. B. at least one flat light guide, which directs the light over a certain distance in its interior. This can mean, for example, that the light with and/or without internal reflections (e.g. total internal reflection due to reflection of the light at an angle greater than the critical angle of total reflection) at the interfaces of the light line ters travels a certain distance within the element, e.g. B. from the coupling of the light to a location of the desired decoupling.

At least one light guide is included in the light guide structure, so in addition to a single light guide, there can also be 2 light guides, 3 light guides, 4 light guides, 5 light guides, 6 light guides, 7 light guides, 8 light guides, 9 light guides, 10 light guides or more than 10 light guides be included. A plurality of light guides are preferably arranged parallel to one another within the light guide structure and in particular have main surfaces arranged parallel to one another.

A flat light guide is preferably such an element as described above, which is flat. In this context, flat means in particular forming a broader surface, flattened and/or expanding on a surface. Two-dimensional can mean, for example, that the light guide has a large extent along a plane or surface and a relatively significantly smaller extent in a direction perpendicular thereto. The plane or surface can also be a curved plane or surface. Significantly smaller extent preferably means an extent smaller by at least a factor of two than the smallest extent along the surface or plane. The planar light guide preferably has a large extent along two parallel main surfaces and a significantly smaller extent along the side surfaces. The side faces preferably extend along the thickness of the planar light guide. In this case, for example, there can be side surfaces with a larger surface area and side surfaces with a smaller surface area, preferably in the case of a cuboid light guide.

The planar light guide is set up for conducting electromagnetic radiation of at least one first spectrum. This preferably means that the planar light guide is essentially transparent to the electromagnetic radiation of the first spectrum.

Transparent preferably means that the light guide is transparent to the electromagnetic radiation of the first spectrum. Transparent means in particular that the base body has a transmittance, based on the intensity of the electromagnetic radiation, of at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90% and/or at least 95%.

Terms such as essentially, approximately, about, approx. etc. preferably describe a tolerance range of less than ±20%, preferably less than ±10%, even more preferably less than ±5% and in particular less than ±1%. Statements of essentially, roughly, about, approx. etc. always reveal and include the exact stated value.

The electromagnetic radiation of the first spectrum preferably includes visible light and in particular light in a wavelength range between 420 nanometers (nm) and 750 nm. The electromagnetic radiation of the first spectrum is preferably also referred to as light in this document. The electromagnetic radiation of the second spectrum can cover the entire visible wavelength range, but it can also include any narrow spectral sub-ranges thereof.

In particular, the holographic decoupling structure can be aimed at a relatively narrow spectral sub-range of the visible light, so that it essentially only diffracts and/or decouples this sub-range.

The light guide preferably comprises a transparent substrate. The light-guiding body can, for example, comprise a transparent glass or PMMA substrate.

The fact that the light guide is set up for conducting electromagnetic radiation of at least one first spectrum also preferably means that it enables the conduction through a corresponding geometric shape. This can mean, for example, that it has correspondingly arranged outer boundary surfaces, which allow light to be guided when coupling is desired by total internal reflection of at least part of the coupled light.

The at least one lighting arrangement arranged on the first side surface of the light guide, comprising at least one light source for emitting electromagnetic radiation with a first spectrum for irradiating electromagnetic radiation with the first spectrum into the light guide, can, according to the wording, comprise one lighting arrangement or several, i.e. at least two, lighting arrangements . 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, ..., 25, ... 30, . .. 40, .

Likewise, each lighting arrangement can comprise one light source or several, ie at least two, light sources. It can be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, ..., 25, ... 30, ... 40, ..., 50 or more light sources be included, wherein the non-listed numbers between the listed numbers are preferably also included.

In the minimum configuration, the lighting assembly includes at least one light source and no other elements. However, it can also be preferred that a lighting arrangement comprises further elements or components in addition to the at least one light source.

The first side surface is preferably a side surface of the light guide. It can be preferred that the light guide includes exactly one side surface. It can also be preferred that the light guide comprises more than one side surface, ie at least two side surfaces, three side surfaces, four side surfaces or even more side surfaces. In this case, each side surface is preferably defined by delimiting edges at which the side surface touches other surfaces of the light guide. In the case of a cuboid light guide, the first side surface is preferably one of the two small-surface side surfaces, but it can also be one of the two large-surface side surfaces. Preferably, a side surface of the light guide is a surface of the light guide that is not a main surface of the light guide.

An illumination arrangement for radiating electromagnetic radiation with the first spectrum into the light guide preferably radiates at least part of the emitted radiation of the first spectrum into the light guide. It is therefore preferably aligned and arranged in accordance with the light guide and has a suitable emission characteristic. The person skilled in the art knows how to meet these requirements with standard components, for example.

A holographic decoupling structure includes, in particular, a hologram. In holography, in contrast to normal images, e.g. photography, in addition to the intensity of the imaged object, phase relationships of the light coming from the object are also stored. These phase relationships contain additional spatial information, which means that a three-dimensional impression of the image can be generated. This is done with the help of interference of light rays during shooting of the object. The object is illuminated with coherent light and is reflected and scattered by the object. The resulting wave field, the so-called object wave, is superimposed with light coherent with the object wave (the so-called reference wave - typically from the same light source, e.g. a laser) and the wave fields interfere with each other as a function of their phase relationship. The resulting interference pattern is recorded, for example, by means of a light-sensitive layer, and the information contained in the phase is thus also stored. For the reconstruction, the resulting hologram is illuminated with a light wave that is identical or similar to the reference wave, which is then diffracted by the recorded interference pattern. In this way, the original wavefront of the object wave can be reconstructed.

The similarity of the light beams used for the reconstruction with the light beams of the reference wave used for recording and/or the properties of the light beams used for recording the hologram are advantageously decisive variables in the quality of the holographic light function generated by the hologram, e.g. the accuracy in the deflection and /or beam shaping of the hologram and/or the sharpness and/or spatial depth in the creation of an image by the hologram. The similarity or the properties of the light beams can be described in particular in relation to the frequency spectrum, the angular spectrum and/or coherence properties of the light beams. The angular spectrum preferably describes the angular components of the illuminating light rays or bundles of rays in relation to a reference straight line and/or reference plane. The angular spectrum is characterized, for example, by the shape of the wave front of the propagating light along the beam path. A plane wave would, for example, cause the decoupling structure to be illuminated from only one angle or the light to propagate along the beam path without divergence, so the angular spectrum would advantageously be equal to zero.

In particular with a small angular spectrum, a good quality of the holographic lighting function, in particular the holographically generated image, the beam shaping performed by the hologram and/or the holographically generated light deflection can advantageously be achieved.

There are different types of holograms, e.g. B. so-called volume holograms. Volume holograms preferably have a thickness that can also be used to store holographic image information.

For example, holograms can be transmission and reflection holograms, which produce this reconstruction either in transmission or in reflection. If you are z. B. in a transmission hologram on a light source opposite side of the holo gram and looks at it, e.g. B. the imaged object in three dimensions in front of you. In the case of a reflection hologram, one must preferably be on the same side as the light source. Reflection holograms preferably have a wavelength selective efficiency that diffracts light in a certain direction (along a certain angle) efficiently.

In addition to the three-dimensional representation, holograms can be used in the form of so-called holographic-optical components (HOE), whose holographic properties can be used for the optics of devices. For example, HOE can replace conventional lenses, mirrors and prisms. In other cases, HOEs are used as special diffraction gratings. For example, HOEs exhibit spectral selectivity and/or incident angle selectivity. At the same time, they can be completely or partially transparent for other spectral ranges and/or angles of incidence.

Holograms, in particular technical holograms, can be recorded directly using various holographic processes or printed from computer-generated data using wavefront printers or stereo holographic printers. These production methods are suitable for mass production of optical functions in the form of holograms, but not because of the high expenditure of time. Suitable replication methods are available for this purpose.

A holographic decoupling structure can preferably be used as such an HOE, which accordingly deflects the electromagnetic radiation of the lighting arrangement that impinges on it, which reaches it through the light guide, in particular of the first spectrum or for parts of the first spectrum, so that it consists of a first Main surface of the light guide structure is coupled out. In this case, the decoupling structure can preferably give a direction to the light impinging on it, which reaches it from the lighting arrangement through the light guide, and/or carry out beam shaping of the beam or bundle of rays of the light. At the same time, the holographic decoupling structure can preferably also assume a hologram function, in that a virtual and/or real image is generated by the light guide when the lighting arrangement is correspondingly illuminated, which image has a three-dimensional appearance in particular. All of this or parts of the above are preferably meant with the feature that the holographic decoupling structure is set up for decoupling guided in the light guide structure electromagnetic radiation of the lighting arrangement from a first main surface of the light guide structure. This is preferably also referred to as the holographic light function of the holographic decoupling structure. This applies in particular to electromagnetic radiation of the first spectrum or at least to spectral sub-ranges of the first spectrum. It is preferred that the decoupling structure has the desired properties only selectively for these partial areas, for example for a spectral range of 5 nm or smaller, 10 nm or smaller or a broader spectral range.

The holographic decoupling structure is preferably arranged in the light guide. For example, the holographic decoupling structure can be written into and/or introduced into the light guide by appropriate techniques known to those skilled in the art.

It can also be preferred that the decoupling structure is comprised of at least one layer applied to the transparent substrate, more preferably to a main surface, in particular to a first main surface. This layer is then preferably encompassed by the light guide, so to speak, and in particular is just as transparent. The at least one layer preferably comprises one or more of the following layers: hologram layer, which preferably comprises the holographic structure, layer comprising triacetate, transparent adhesive layer or adhesive film (e.g. OCA) and/or layer/foil comprising polycarbonate (PC.) The layer can in particular comprise a foil, e.g. B. a hologram film, a triacetate film, an adhesive film and / or a polycarbonate film. The layer and the decoupling structure comprised by the layer are preferably two-dimensional and comprise a main surface of the light guide or are parallel to it. This can also be referred to, for example, as an arrangement of the decoupling structure on the light guide.

The decoupling structure is preferably flat.

The holographic decoupling structure is preferably arranged parallel to the main surface, in particular parallel to the first main surface. The parallelism relates in particular to structural elements of the decoupling structure, for example the arrangement of modulations of the refractive index within the decoupling structure and/or the areal extent of the decoupling structure.

The first main surface of the light guide structure is preferably a main surface of a light guide. Each included light guide preferably has at least one first main surface, preferably several main surfaces, ie also at least one second main surface. With several, preferably parallel With the light guides arranged relative to one another, the main surface comprises, in particular, an outer surface of the light guide structure, which in turn comprises an outer, in particular first, main surface of a light guide of the light guide structure. An external main surface of one of several light guides of the light guide structure is in particular a main surface of a light guide structure which is not oriented towards a further light guide. If the light guide structure comprises, for example, two light guides arranged in parallel, which are essentially cuboid and each have two main surfaces, two main surfaces of the light guides, one of one light guide and the other of the other light guide, are arranged to one another or directly next to each other and preferably on the inside in relation to each other to the entire light guide structure. This is preferably the second main surface of the respective light guides. The other two main surfaces of the two light guides are preferably on the outside and oriented away from one another in relation to the entire light guide structure. These main surfaces are preferably referred to as the main surfaces of the light guide structure. This is preferably the respective first main surface of the light guide. If, for example, only a single light guide is comprised by the light guide structure, each of the main surfaces of the light guide, ie in particular its first and second main surface, preferably forms a main surface of the light guide structure. In this case, the light guide structure can preferably have a plurality of main surfaces, in particular two main surfaces, which are formed in particular by a respective main surface of the at least one included light guide. One of these main surfaces is preferably the first main surface and the other the second main surface of the light guide structure.

A holographic decoupling structure spaced apart from the first side surface is spaced apart from the first side surface on which the lighting arrangement is present. This distance can be in the centimeter range, for example. Thus, the light guide is preferably functionally structured into an area on the first side surface, where the illumination is carried out, and an area spaced apart from this side surface, at which the decoupling from the first main surface takes place through the holographic decoupling structure.

However, it can also be preferable for the holographic coupling-out surface to be present or adjacent directly to the first side surface.

The decoupling structure preferably has an acceptance angle spectrum. This preferably means that the decoupling structure has the desired, e.g. B. the above-described properties, in particular that the decoupling structure is set up as described herein for decoupling guided in the light guide structure electromagnetic radiation of the lighting arrangement from a first main surface of the light guide structure, only fulfilled if the light coming through the light guide from the lighting arrangement to it inside of a specific angular range with respect to the decoupling structure, on a surface comprised by the decoupling structure and/or with respect to the first main surface of the light guide structure. Thus, advantageously, it can be said that the acceptance angle spectrum comprises the angles that generate a good holographic function/image. This angle or range of angles is preferably measured using a light beam in relation to a straight line or a plane, as described in this document. The area encompassed by the decoupling structure can relate in particular to an area within which structural elements of the decoupling structure are arranged, for example the arrangement of modulations of the refractive index within the decoupling structure. It can also mean the area along the planar extent of the decoupling structure.

This angular range is preferably called the acceptance angle spectrum and includes in particular the angular range for which the decoupling hologram for the first spectrum and/or parts of the first spectrum has the desired properties described here. In particular, the acceptance angle spectrum is defined with regard to the efficiency of the holographic decoupling structure, in particular with regard to the decoupling efficiency, which is considered as a function of the angle range described above. The efficiency can preferably assume values between 0 (e.g. no light is coupled out) and 1 (all light is coupled out). In this case, the acceptance angle spectrum is preferably defined in that the decoupling efficiency for the angle range encompassed is 0.1 or greater, more preferably at least 0.5.

The acceptance angle spectrum is measured in particular in relation to the surface normal of the decoupling structure, the surface normal of the surface encompassed by the decoupling structure and/or the surface normal to the first main surface of the light guide structure.

The acceptance angle spectrum can also be measured in relation to or defined around the reconstruction angle. The reconstruction angle is preferably the angle at which the holographic decoupling structure was recorded and/or at which the decoupling efficiency is at a maximum. The acceptance angle spectrum is preferably determined by the distribution of the Auskop pelefficiency around the reconstruction angle is determined. The reconstruction angle can preferably be measured in relation to the surface normal of the decoupling structure, to the surface normal of the surface comprised by the decoupling structure and/or the surface normal to the first main surface of the light guide structure.

The angle spectrum impinging on the decoupling structure can preferably be determined by determining the square mean of the difference of all angles from the target reconstruction angle (preferably the so-called RMS radius). This can then be compared to the acceptance angle spectrum.

In principle, this can preferably mean the (acceptance) angle spectrum in the vertical direction, i.e. preferably the (acceptance) angle spectrum or its projection in relation to a cross-sectional plane of the light guide and/or the (acceptance) angle spectrum in the horizontal direction, i.e. preferably that Angular spectrum or its projection in relation to a longitudinal section plane of the light guide or perpendicular to the coupling surface (to the first side surface). Depending on this, the angle is preferably measured in relation to the respective plane.

In this document, the (acceptance) angular spectrum preferably means the (acceptance) angular spectrum in the horizontal direction.

It can also be preferred to measure the acceptance angle spectrum in general in relation to the aforementioned surface normal, without referring to one of the directions mentioned.

The cross-sectional plane is defined, for example, as a plane parallel to the first side face. The cross-sectional plane is preferably radiated through by coupled light beams and is, for example, perpendicular to a main beam direction of the light beams of the lighting arrangement coupled into the light guide.

A main beam direction is preferably a direction in which there is a maximum intensity or intensity of the light beam or bundle of rays that is averaged over all directions. The term main ray or main ray direction preferably designates the central ray of a bundle of rays or its direction. The direction of the principal ray indicates in particular the direction of the bundle of rays. In the case of a collimated beam of rays, the remaining rays of the beam of rays run essentially parallel to the main beam direction, so that the main beam direction is preferably representative of the rays of a beam of rays. In the case of a non-collimated beam of rays, the rays of the beam of rays span a defined solid angle, in the center of which runs the main beam direction.

The longitudinal sectional plane is defined, for example, as a plane perpendicular to the first side surface, in which the surface normal of the decoupling structure, the surface encompassed by the decoupling structure and/or the first main surface of the light guide structure. The longitudinal section plane can preferably be a surface perpendicular to the cross-sectional plane. The longitudinal sectional plane is preferably along or parallel to a main beam direction of the light beams of the lighting arrangement coupled into the light guide.

The angular spectrum of the electromagnetic radiation radiated in by the lighting arrangement and/or emitted by the light source in the direction of the light guide is preferably at least 15°, preferably at least 20°, more preferably at least 30° and in particular at least 40°. With this angular spectrum is preferably the angular distribution of the electromagnetic radiation that is irradiated and/or emitted by the light source in the direction of the light guide in relation to a surface normal, in relation to the centroid angle of the electromagnetic radiation that is irradiated and/or emitted by the light source in the direction of the light guide and/or in relation to the reconstruction angle of the decoupling structure.

The centroid angle is preferably the angle measured in relation to a surface normal at which the incident and/or emitted light intensity is greatest.

The radiated angle spectrum preferably denotes the angle spectrum radiated into the light guide by the lighting arrangement, which is preferably measured in the same way (with the same reference straight line and/or plane) as described above for the acceptance angle spectrum of the decoupling structure, whereby a distinction can preferably also be made between angle spectrums in vertical direction and angular spectrum in horizontal direction or not. The radiated angular spectrum can preferably also be measured in relation to a main beam direction of the radiated light. It can also be preferred that the radiated angle spectrum is measured analogously to the acceptance angle spectrum of the decoupling structure, with the reference line, the normal or plane, on the basis of which the angle spectrum is measured, being shifted in parallel such that, for example, at the irradiation location (at the first side surface) or in the area of the irradiation location acc will sen. The irradiated angular spectrum is preferably the angular range in which an irradiated intensity can be measured and/or should be present based on calculations. The radiated angular spectrum can be determined, for example, in relation to a number between 0 and 1, which is called the relative radiated intensity. This number determines whether there is a relative irradiated intensity within a specific angle or angle range, which is measured as described above. For example, this relative irradiated intensity can be normalized in relation to the maximum irradiated intensity at a specific angle or angle range within the angle spectrum. The relative irradiated intensity then assumes the value 1 at the at least one angle within the angular range at which the irradiated intensity is maximum, and the value 0 is assumed if no measurable intensity is irradiated at all. The radiated angular spectrum is preferably defined in that the relative radiated intensity is 0.1 or greater for the angular range covered. Alternatively, the angle spectrum radiated in can be defined in that an intensity radiated in there is greater than 0, preferably greater than 0.1 μm, taking into account any measurement and/or calculation uncertainties (e.g. noise).

The angular spectrum of the electromagnetic radiation emitted by the light source in the direction of the light guide preferably designates the angular spectrum of the electromagnetic radiation emitted by the light source in the direction of the light guide before irradiation into the light guide and/or before any beam shaping. “In the direction of the light guide” preferably designates the emitted light beams, which point in the direction of a half-space defined by the first side surface within the light guide. This preferably refers to the angular spectrum emitted by the light source, which can potentially be radiated into the light guide, depending on the nature of the lighting arrangement, the elements present between the light source and the light guide and/or the light guide, because this is fundamentally possible from the direction. This angular spectrum is preferably measured in the same way as the acceptance angle spectrum of the decoupling structure, with the reference line, the normal or plane, on the basis of which the angular spectrum is measured, being shifted in parallel such that the measurement is taken at the location where the light source and/or the first side surface is arranged. The angular spectrum of the electromagnetic radiation emitted by the light source in the direction of the light guide can preferably also be measured in relation to a main beam direction of the electromagnetic radiation emitted by the light source in the direction of the light guide. In this angular spectrum, a distinction can preferably also be made between the angular spectrum in the vertical direction and the angular spectrum in the horizontal direction, or not. This angular spectrum is preferably the angular range in which an intensity emitted in the direction of the light guide can be measured and/or should be present based on calculations. This angular spectrum can be determined, for example, in relation to a number between 0 and 1, called the relative intensity emitted towards the light guide. This number determines whether there is a relative intensity emitted in the direction of the light guide within a certain angle or angular range, which is measured as described above. For example, this relative intensity emitted in the direction of the light guide can be normalized with respect to the maximum intensity emitted in the direction of the light guide at a certain angle or angular range within the angular spectrum. The relative intensity emitted in the direction of the light guide then assumes the value 1 at the at least one angle within the angular range at which the radiated intensity is maximum, and the value 0 is assumed if no measurable intensity is radiated at all. The angular spectrum emitted in the direction of the light guide is preferably defined in that the relative intensity emitted in the direction of the light guide is 0.1 or greater for the angle range encompassed. Alternatively, the radiated angular spectrum can be defined in that an intensity emitted in the direction of the light guide is greater than 0, preferably greater than 0.1 μm, taking into account any measurement and/or calculation uncertainties (e.g. noise).

The angular spectra mentioned in the previous paragraph can be realized in particular through the choice of the light source, the lighting arrangement, any use of beam-shaping components, the non-use of beam-shaping components, etc. Such an angle spectrum can be realized in particular when selecting a light source that is as simple as possible without beam-shaping components.

The characteristics of the beam of rays of the emitted or coupled-in light can preferably be described by the features described above and can advantageously be related to the guided angle spectrum and/or the acceptance angle spectrum of the holographic decoupling structure.

The angle spectrum of the radiated electromagnetic radiation conducted in the light guide from the lighting arrangement to the holographic decoupling structure, especially the first spectrum rums is preferably the angular spectrum of the electromagnetic radiation emitted by the light source, in particular of the first spectrum, which is radiated into the light guide and is located within the light guide up to the decoupling structure. This angle spectrum is preferably measured in the same way as the acceptance angle spectrum of the decoupling structure described above, it being possible to differentiate between the angle spectrum in the vertical direction and the angle spectrum in the horizontal direction or not. The angular spectrum of the radiated electromagnetic radiation conducted in the light guide from the lighting arrangement to the holographic decoupling structure can also be measured in relation to a main beam direction of the electromagnetic radiation guided in the light guide from the lighting arrangement to the holographic decoupling structure.

The absolute value of the angular spectrum of the irradiated electromagnetic radiation and/or the acceptance angle spectrum of the holographic decoupling structure conducted in the light guide from the illumination arrangement to the holographic decoupling structure is at most 5°.

In absolute terms, preferably means that the angle around the reference line (e.g. surface normal) or reference plane (e.g. cross-sectional plane and/or longitudinal sectional plane) is always referred to as a positive value, regardless of the respective direction in which the measurement is made. In this case, the smallest of all possible angles which is enclosed between the reference straight line and/or reference plane and the light beam under consideration is preferably always measured. If, for example, directions were taken into account when measuring the angle, an angle measured in one direction, e.g. B. can be denoted by +3°, with the same dimensional angle measured in the opposite direction being denoted by -3°. In absolute terms, this angle is then preferably always +3°. This definition of "in terms of amount" preferably also applies in other contexts in which the word in terms of amount is used.

The acceptance angle spectrum of the holographic decoupling structure can preferably be realized by appropriate production, for example appropriate illumination or exposure during recording.

The angular spectrum conducted in the light guide can be increased, for example, by a corresponding geometry of the light guide (e.g. a tapering of the light guide from the lighting arrangement to the decoupling surface, in particular combined with a correspondingly shaped side surface, e.g. a stepped tapering with stepped sections, which are at an angle to the main beam direction in the Have an essentially vertical orientation) and/or a corresponding design of the refractive index of the light guide (e.g. a refractive index modulation within the light guide, which correspondingly deflects light beams that are not essentially parallel to the main beam direction and/or a small difference in refractive index between the light guide on the outer surfaces and the environment , making total internal reflection difficult). For example, gradient optics can be used.

In all cases, it may be preferable for the spectral width of the electromagnetic radiation emitted by the light source and/or the lighting arrangement and/or the acceptance frequency spectrum (see below for further explanations on the acceptance frequency spectrum) of the holographic decoupling structure to have an upper limit, since too broad a decoupled frequency spectrum can adversely limit the quality of the display.

In order to limit a broad emission spectrum of the light source through the lighting arrangement, the lighting arrangement can, for example, have a corresponding spectral filter, e.g. B. have a bandpass filter. Such is easy and inexpensive to implement, z. B. by a film with filter properties between the light source and the first side surface of the light guide.

The spectral limitation can be 20 nm or less, preferably 10 nm or less, more preferably 5 nm or less, even more preferably 2 nm or less and in particular 1 nm or less.

With the invention, an at least acceptable functionality of the holographic lighting function of the holographic Outcoupling structure can be achieved by limiting the acceptance angle spectrum and/or the angle spectrum guided to it through the light guide. This can preferably be understood as the realization of a type of “filter function” for the angles accepted by the decoupling structure or for the angles directed to the decoupling structure. In this way, for example, an inexpensive light guide can be realized with an improved holographic lighting function.

In a preferred embodiment of the invention, the lighting is in the light guide tion arrangement for the holographic decoupling structure conducted angle spectrum of the radiated electromagnetic radiation in terms of absolute value at most 25 °, preferably at most 20 °. A simple and inexpensive light guide can thus be used which does not require complex geometries and/or configurations of the refractive index.

In a further preferred embodiment of the invention, the absolute value of the acceptance angle spectrum of the holographic decoupling structure is at most 5°. A “filter function” can thus be implemented particularly effectively, which implements a high optical quality of the holographic lighting function.

In this embodiment, it can be preferred that the angular spectrum of the radiated electromagnetic radiation conducted in the light guide from the lighting arrangement to the holographic decoupling structure is significantly larger, for example this can be at least 15°, more preferably at least 20°, even more preferably at least 30° and in particular be at least 40°.

The acceptance angle spectrum of the holographic decoupling structure is preferably at most 4°, more preferably at most 3°, even more preferably at most 2° and in particular at most 1°. In this way, the optical quality of the holographic decoupling structure, in particular its holographic lighting function, can be further improved.

In a preferred embodiment of the invention, the absolute value of the angular spectrum of the radiated electromagnetic radiation in the light guide from the lighting arrangement to the holographic decoupling structure is at most 25°, preferably at most 20°, with the absolute value of the acceptance angle spectrum of the holographic decoupling structure being at most 5°. In this way, the advantages of the above embodiments can be combined.

In a further preferred embodiment of the invention, the holographic decoupling structure is set up for a maximum of the acceptance angle spectrum and/or a reconstruction angle, which and/or which essentially correspond to a maximum of the angle spectrum of the light radiated in by the lighting arrangement and/or in the light guide of the lighting arrangement to the holographic decoupling structure conducted angle spectrum of the radiated electromagnetic radiation corresponds.

A maximum of the acceptance angle spectrum preferably designates the at least one angle or the at least one angle range within the acceptance angle spectrum at which the efficiency of the holographic decoupling structure is greatest. This maximum can in particular be referred to as the reconstruction angle.

The maximum of the angular spectrum of the light radiated in by the lighting arrangement preferably designates the at least one angle or the at least one angular range within the angular spectrum of the light radiated in by the lighting arrangement at which the most light is radiated in by the lighting arrangement. "Most" preferably refers to the magnitude of the light intensity or to the magnitude of the proportion within an angle or angular range in relation to the total incident light within the angular spectrum.

The maximum of the angular spectrum of the light radiated in by the lighting arrangement preferably designates the main beam direction of the light radiated in by the lighting arrangement.

The maximum of the angular spectrum of the radiated electromagnetic radiation conducted in the light guide from the illumination arrangement to the holographic decoupling structure preferably designates the at least one angle or the at least one angular range within the angular spectrum of the radiated electromagnetic radiation in which most of the radiated electromagnetic radiation is conducted from the illumination arrangement to the holographic decoupling structure becomes. "Most" preferably refers to the magnitude of the intensity of the electromagnetic radiation concerned, or to the magnitude of the fraction of the conducted radiation within an angle or range of angles with respect to the total conducted radiation within the angular spectrum.

The maximum of the angular spectrum conducted in the light guide from the lighting arrangement to the holographic decoupling structure preferably designates the main beam direction of the light guided in the light guide from the lighting arrangement to the holographic decoupling structure

If the maxima are matched to one another as described, the efficiency of the light guide structure can advantageously be improved.

In a further preferred embodiment of the invention, more than one holographic decoupling structure is included, in particular up to five holographic decoupling structures, each holographic decoupling structure having a different acceptance angle spectrum and/or a different reconstruction angle within the angle spectrum of the electromagnetic radiation radiated in by the illumination arrangement and/or emitted by the light source in the direction of the light guide.

The outcoupling structures preferably have essentially the same outcoupling properties, in particular the same beam steering and/or beam shaping of the outcoupled light beams.

The acceptance angle spectra of the included decoupling structures are preferably essentially directly adjacent and/or have a partial overlap. This means in particular that the outcoupling efficiency between two adjacent outcoupling structures is not less than 0.3.

The decoupling structures are preferably arranged parallel to the main surface congruently, in particular in the direction of a surface normal, as defined above one above the other.

The holographic decoupling structures can be arranged one above the other, in particular stacked one above the other, in a so-called stack.

It can also be preferred that the decoupling structures are arranged next to one another in a first direction from the lighting arrangement in the direction of the decoupling structure.

It can be preferred that the holographic decoupling structures (whether side by side or one above the other) are present in a single decoupling hologram, in particular in a so-called hologram film in which they were exposed together. Such a decoupling hologram is preferably also referred to as a so-called multiplex hologram.

The acceptance angle spectrum of each individual holographic decoupling structure is preferably at most 4°, more preferably at most 3°, even more preferably at most 2° and in particular at most 1°.

Due to the fact that in this embodiment several decoupling structures with the properties mentioned are included, a high optical quality, e.g high decoupling efficiency over the angular range encompassed by the individual acceptance angle spectra of the single decoupling structures a high decoupling efficiency can be achieved. Improved decoupling properties are thus advantageously paired with a high decoupling efficiency.

In a further preferred embodiment of the invention, the frequency spectrum of the light source comprises at least 2 nm, more preferably at least 10 nm, in particular at least 20 nm, with the acceptance frequency spectrum of the decoupling structure comprising at most 20 nm, more preferably at most 10 nm and in particular at most 2 nm and with the Maxima of the frequency spectrum and the acceptance frequency spectrum essentially match.

The frequency spectrum of the light source can be, for example, the spectral range of the emitted electromagnetic radiation, in which significant portions of the intensity of the emitted electromagnetic radiation are located. For example, substantial proportions may be 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more.

The acceptance frequency spectrum of the decoupling structure is preferably described with regard to the spectral efficiency of the holographic decoupling structure, in particular the spectral decoupling efficiency. This preferably describes the decoupling efficiency in relation to the frequency spectrum of the light beams impinging on it, which are in particular within the acceptance frequency spectrum of the decoupling surface. This efficiency can preferably assume values between 0 (e.g. no light is coupled out) and 1 (all light is coupled out) for different frequencies of the light. In this case, the acceptance frequency spectrum is preferably defined in that the decoupling efficiency for the frequency range covered is 0.1 or greater, more preferably 0.5 or greater.

The at least one maximum of the frequency spectrum preferably includes the at least one frequency and/or the at least one frequency range which has the maximum intensity within the frequency spectrum.

The at least one maximum of the acceptance frequency spectrum preferably designates the at least one frequency or the at least one frequency range within the acceptance frequency spectrum at which the efficiency of the holographic decoupling structure is greatest.

The larger the frequency spectrum decoupled from the decoupling structure, the lower is, for example, the quality of the holographic function generated during decoupling. In the case of a holographically generated image, for example, the different frequency ranges are decoupled at different angles, so that a blurred image and/or an image that is multicolored at the edges can arise.

In particular, the decoupling and/or the quality of the holographic lighting function can be improved by the advantageous limitation of the emitted frequency spectrum and/or the accepted frequency spectrum. At the same time, essentially inexpensive standard components can be used for the light guide, particularly with regard to the light source.

• i. durch das Verhältnis zwischen dem Winkelspektrum der eingestrahlten elektromagnetischen Strahlung und dem Überlapp des Winkelspektrums der eingestrahlten elektromagnetischen Strahlung mit dem im Lichtleiter von der Beleuchtungsanordnung zur holographischen Auskoppelstruktur geleiteten Winkelspektrum und dem Akzeptanzwinkelspektrum der holographischen Auskoppelstruktur und/oder
• ii. durch das Verhältnis zwischen dem Frequenzspektrum der Lichtquelle und dem Überlapp des Frequenzspektrums der Lichtquelle und dem Akzeptanzfrequenzspektrum der holographischen Auskoppelstruktur.

In a further preferred embodiment of the invention, the intensity of the lighting arrangement is essentially proportional to a basic intensity of the lighting arrangement multiplied by an inverse of the decoupling loss, which is characterized

• i. by the ratio between the angular spectrum of the radiated electromagnetic radiation and the overlap of the angular spectrum of the radiated electromagnetic radiation with the angular spectrum conducted in the light guide from the lighting arrangement to the holographic decoupling structure and the acceptance angle spectrum of the holographic decoupling structure and/or
• ii. by the ratio between the frequency spectrum of the light source and the overlap of the frequency spectrum of the light source and the acceptance frequency spectrum of the holographic output coupling structure.

The intensity of the lighting arrangement preferably designates the intensity of the electromagnetic radiation of the first spectrum emitted by the lighting arrangement. In particular, this designates the intensity of the electromagnetic radiation of the first spectrum emitted by the light source.

Two sizes are proportionally preferred if they are always in the same ratio to one another. This ratio is preferably called the proportionality factor. What is meant here in particular is that the intensity of the lighting arrangement essentially corresponds to the basic intensity of the lighting arrangement multiplied by an inverse of the decoupling loss.

The basic intensity of the lighting arrangement is preferably an intensity unit of the lighting arrangement, which enables meaningful scaling based on the decoupling loss.

The basic intensity of the lighting arrangement can include, for example, the intensity of a single standard LED that is to be used for the light guide. In addition to using an LED with a larger luminous flux, the corresponding adaptation to the coupling loss can then be compensated for by using a corresponding number of standard LEDs in order to compensate for the coupling loss. Therefore, the basic intensity is preferably small enough to enable a substantial correspondence, since only a number of whole LEDs can be used and the basic intensity thus dictates the resolution of the adaptability of the intensity of the lighting arrangement to the coupling loss.

The basic intensity can also specify the resolution of the adjustability of only one light source or multiple light sources, for example given by the possibilities for regulating the intensity of the light source and/or by the light source itself.

By multiplying the basic intensity by the inverse decoupling loss, this can advantageously be compensated for, whereby a sufficient intensity of light decoupled by the decoupling structure can be achieved even with simple optical beam guidance and at the same time a low acceptance angle spectrum and/or acceptance frequency spectrum.

An overlap of the respective angle spectra and the acceptance angle spectrum preferably describes all angles measured and/or calculated in the same way, which lie both within the named angle spectra and within the acceptance angle spectrum. This at least one angular range preferably represents the overlap. If, for example, the angular spectrum of the radiated electromagnetic radiation is 20°, the angular spectrum guided in the light guide from the lighting arrangement to the holographic decoupling structure is 15° and the acceptance angle spectrum is 5°, the overlap is preferably 5°.

The ratio between the angular spectrum of the radiated electromagnetic radiation and the overlap preferably describes the proportional ratio of the overlap with the radiated angular spectrum and is in particular a number less than 1. In the example above, this ratio, for example, results from the ratio of 5° (the overlap) and 20° (the radiated angle spectrum) and is 5/20, i.e. ¼.

This ratio would preferably describe the decoupling loss, with the inverse of the decoupling loss preferably being described by the inverse of the decoupling loss. In the example above, this inverse would be 4.

The inverse or multiplicative inverse of the decoupling loss is preferably the reciprocal of the decoupling loss. In particular, the inverse of the decoupling loss is the number by which the decoupling loss must be multiplied to get 1.

By multiplying the basic intensity by the inverse of the decoupling loss, this can preferably be compensated for and certain losses due to a simple structure of the light guide and/or the lighting arrangement can also be compensated for by simply increasing the intensity.

The overlap of the frequency spectrum of the light source and the acceptance frequency spectrum of the holographic decoupling structure preferably designates the at least one frequency range which is covered both by the frequency spectrum of the light source and by the acceptance frequency spectrum.

The ratio between the frequency spectrum of the light source and the overlap of the frequency spectrum of the light source and the acceptance frequency spectrum of the holographic preferably the proportional ratio of the overlap with the radiated frequency spectrum and is in particular a number less than 1. This ratio preferably gives the spectral component of the frequency spectrum that can be used by the decoupling structure the light source again.

In a further preferred embodiment of the invention, a basic intensity of the lighting arrangement comprises at least a photometric luminous flux of 5 lm. Such a value has proven to be particularly well scalable and therefore suitable for the light guide structure. There are, for example, individual light sources, in particular individual LEDs, which emit a luminous flux of this magnitude. Thus, in addition to using an LED with a larger luminous flux, the intensity can advantageously be adapted to the coupling loss via the number of light sources. Since LEDs in particular are inexpensive mass-produced goods, controlling the intensity of the emitted light beams via the number of LEDs used is particularly inexpensive and simpler and cheaper than controlling the intensity via complex beam shaping and/or coupling of the lighting arrangement.

In a further preferred embodiment of the invention, the light guide has a maximum thickness of 5 mm, preferably 3 mm, perpendicular to the planar extent. Such a light guide has proven to be particularly useful and easy to install and/or modify for a large number of applications, for example for an operating element and/or an entry strip in a door frame of a vehicle. The optical properties of the light guide can also be positively influenced by this thickness. For example, a guided and/or irradiated angle spectrum of the lighting arrangement can be limited in this way and the optical quality of the light beams coupled out can advantageously be increased.

Optical quality refers here in particular to the extent to which light beams and/or light beam bundles match desired properties, e.g. B. regarding, collimation, divergence and / or sharpness of an image represented by the light rays.

In a further preferred embodiment of the invention, at least part of the electromagnetic radiation radiated in by the lighting arrangement is conducted without prior total internal reflection within the light guide between the lighting arrangement and the holographic decoupling structure. Such direct illumination of the holographic decoupling structure by the illumination arrangement places particularly low demands on radiation into the light guide (coupling), beam guidance within the light guide and/or refractive index adjustment of the light guide for total internal reflection of the light beams in the light guide. At the same time, the angular spectrum of the light beams of the lighting arrangement guided in the light guide to the decoupling structure can be limited and/or determined by simple geometric relationships.

In a further preferred embodiment of the invention, the light source is selected from the group consisting of lasers and/or LEDs. These light sources are particularly suitable for the light guide structure, their emission properties can be adapted particularly well to the holographic decoupling structure and they are also inexpensive standard components.

In a further preferred embodiment of the invention, more than one light source is included, with the plurality of light sources being arranged next to one another along the first side surface present. Side-by-side along the side face preferably means juxtaposed in the direction along the longer extent of the side face. A particularly advantageous illumination of the holographic decoupling structure, in particular in the vertical direction, can be achieved by distributing a plurality of light sources next to one another. In addition, the light sources can be arranged next to one another in a particularly simple manner, in particular in the case of a thin light guide.

In a further preferred embodiment of the invention, the lighting arrangement comprises at least one beam-shaping element which is arranged between the light source and the first side surface and which is selected from the group consisting of a lens, diffuser, prism, holographic structure and/or grating. In particular, combinations of these components can be included. In this embodiment, desired beam properties of the light beams illuminating the outcoupling structure can be achieved in a particularly simple manner, as a result of which improved outcoupling can take place.

In a further preferred embodiment of the invention, the lighting arrangement does not include any additional beam-shaping element, the light source being arranged directly on the first side surface of the light guide. As a result, a particularly simple and inexpensive light guide structure can be provided. Good decoupling can be achieved at the same time, particularly in connection with the features described here for the angle spectrum and acceptance angle spectrum.

In a further preferred embodiment of the invention, the light guide and lighting arrangement are present together in a monolithic component.

Monolithic preferably means consisting of one piece or in one piece. In this case, monolithic can in particular mean manufactured from one piece (eg the raw material of the light-conducting body). However, it can also mean that individual components are assembled to form a one-piece component, in particular in such a way that after assembly it is no longer possible to simply reverse this assembly process and/or that the components are brought together in the most compact and stable form possible. Monolithic can preferably also mean that the components put together to form a piece are essentially homogenous with regard to at least one property, for example with regard to strength, transparency and/or refractive index.

A monolithic component is particularly robust, easy to install and low-maintenance. In particular, the lighting arrangement and/or lighting arrangement and light guide do not require any (further) (re)adjustment in relation to one another.

In a further preferred embodiment of the invention, the lighting arrangement is connected directly to the first side surface of the light guide by an injection molding process.

An injection molding process is preferably a primary shaping process, particularly in plastics processing. The material used is preferably liquefied using an injection molding machine and injected into a mold under pressure, where it returns to a solid state through cooling and/or a crosslinking reaction. The hollow space or cavity of the tool determines the shape and/or surface structure. After the mold has been opened, the resulting finished part can be removed.

The at least one component of the lighting arrangement is preferably arranged beforehand on the light guide and/or the light guide substrate and then firmly connected thereto during the injection molding process, in particular to form a monolithic component. The components of the lighting arrangement can also be partially or completely enclosed by the injection molding material used.

A lighting arrangement connected to the light guide by an injection molding process advantageously results in a particularly homogeneous and stable component. Any cavities between the at least one component of the lighting arrangement and the light guide are in particular closed by the pressure used in the injection molding process, as a result of which a desired refractive index adjustment between individual parts can be achieved. In this way, in particular, improved optical properties can be realized compared to other types of connection.

A person skilled in the art can thus distinguish a lighting arrangement connected to the light guide by such an injection molding process from other types of connection.

In a further preferred embodiment, the light guide substrate is produced by an injection molding process and is connected to the lighting arrangement on the first side face of the light guide. A particularly simple and inexpensive monolithic light guide structure can thus be produced be made, which differs in terms of improved stability and / or homogeneity of differently manufactured light guide structures.

In a further preferred embodiment of the invention, the first side surface has a smooth surface, which was preferably obtained by a polishing process, more preferably P3 polishing, and/or which preferably has a square roughness _Rq of less than 2 nm.

A smooth surface is characterized in particular by a low level of roughness. Roughness refers in particular to the unevenness of the surface height. For example, roughness can be quantified by an average roughness R _a and/or a quadratic roughness R _q .

Those skilled in the art know how R _a and R _q are defined and how they can be measured.

The average roughness value R _a indicates, for example, an average distance between surface points of a described surface and the so-called center line of the surface. The center line preferably intersects the actual surface profile within a reference distance of the surface under consideration in such a way that a sum of the profile deviations is distributed over the length of the reference distance in a plane parallel to the center line. The mean roughness value preferably corresponds to the arithmetic mean of the amount of deviation of the surface from the center line.

The squared roughness _Rq (English: rms roughness or root-mean-squared roughness, i.e. root of the mean square) is calculated, for example, from the mean of the squares of deviation and preferably corresponds to the "square mean" of the deviation of the surface from the center line.

A polishing process is preferably a process in which material is removed in small amounts from a surface with the aim of smoothing the surface.

A P3 polish preferably creates particularly smooth surfaces that can be distinguished from other polished surfaces. For example, a surface treated with a P3 polish has a square root roughness _Rq of less than 2 nanometers (nm).

With an R _q of less than 2 nanometers (nm), beams can be irradiated and/or coupled particularly well into the light guide body, even without an additional beam-shaping component of the lighting device. In particular, essentially no undesired scattering and/or diffusion processes take place on the side surface.

Especially in connection with a lighting arrangement that includes a monolithic component with the light guide, preferably in the case of a lighting arrangement that is directly connected to the first side surface of the light guide by an injection molding process, especially if no additional beam-shaping components are included in the lighting arrangement, such a smooth Surface high efficiency in the irradiation and a good quality of the coupled light beams can be achieved with a simultaneously cheap and simple structure of the light guide. A particularly simple matching between the coupled angle spectrum and the acceptance angle spectrum of the decoupling structure can then be implemented.

In a further preferred embodiment of the invention, the surface of the first side surface is set up to act as a diffuser for the electromagnetic radiation conducted between the beam-shaping element and the light guide and in particular has a squared roughness greater than 2 nm.

The surface of the first side surface is preferably also referred to as the coupling surface.

A diffuser is preferably a surface and/or a spatial area that is set up for scattering incident light. In this case, in particular, scattering due to total reflection and/or light refraction can be used. For this purpose it is particularly preferred that a surface is used with a roughness such that the refraction and/or reflection in a specific direction generated by the surface is essentially subject to a statistical distribution. In particular, a roughness of more than 2 nm has proven to be advantageous.

A desired distribution of beam directions of different beam bundles in the light guide can advantageously be achieved by the scattering at the diffuser. A relatively uniform illumination of the decoupling surface can preferably be achieved with regard to the intensity and/or angle of the illumination, in particular within the acceptance angle spectrum.

In a further preferred embodiment of the invention, the holographic decoupling structure is set up for a holographic representation by generating a real and/or virtual image in and/or outside the light guide structure and in particular within the first main surface of the light guide structure (in-plane), wherein the holographic representation preferably essentially only represents structures which can be resolved at the acceptance angle spectrum of 5° and/or are recognizable as such by an observer.

A holographic representation is in particular a realization of a holographic lighting function. The images generated by the holographic representation can preferably generate a spatial impression for an observer, primarily because phase information of the image and thus spatial depth information can also be represented by the decoupling hologram.

The images generated can preferably include structures which, for example, include recognizable lines or shapes of the displayed image or through which the image becomes recognizable. For example, an arrow can be represented by the decoupled light beams of the light guide, with the structures comprising the arrow and, above all, the boundary lines of the arrow. Only structures that can be resolved in the acceptance angle spectrum of 5° are preferably displayed. For example, in order for the arrow to be recognizable, the boundary lines must be clearly recognizable, particularly in relation to the size dimension of the arrow shown. For example, if the arrow is small and the boundary lines are blurred by a magnitude equal to the magnitude of the arrow, the arrow may e.g. B. can no longer be resolved and therefore not recognizable. This can occur in particular due to an acceptance angle spectrum that is too large in relation to the size of the structures shown. Then the decoupled light beams will typically also have an angle spectrum that is too large and the structures will become z. B. blurred. Such an arrow as in the example above should advantageously not be represented by the decoupling structure. Rather, the displayed images and/or structures should advantageously be adapted to the acceptance angle spectrum and thus also to the decoupled angle spectrum.

In a further preferred embodiment of the invention, several holographic decoupling structures are included, each holographic decoupling structure being set up to generate the same image. As described, the acceptance angle spectrum can be kept small for each decoupling structure and the image of the respective decoupling structure can be kept sharp as a result. Overall, a larger part of the angular spectrum of the light radiated into the light guide can be used in order to increase the lighting efficiency. Since each decoupling structure generates the same image and these same images are superimposed, a brighter image can be generated with the same illumination intensity and the efficiency of the light guide structure can be increased.

In a further preferred embodiment of the invention, the display only shows structures larger than 1 mm and/or the spatial depth of the display, preferably in the viewing direction, is less than 20 mm.

A spatial depth of the representation comprises, in particular, a structural component perceived by the seemingly three-dimensional representation of the decoupling hologram in the viewing direction and/or perpendicular to the first main surface of the light guide structure. A preferred viewing direction is preferably essentially perpendicular to the first main surface of the light guide structure. In contrast to classic images created by light rays, holographic images can have a three-dimensional depth, e.g. B. have in the viewing direction. However, the resolution and/or perceptibility of the representation of this spatial depth is typically dependent on the angle spectrum and/or the frequency spectrum of the diffracted (here: decoupled) light rays and thus in particular also on the acceptance angle spectrum and/or acceptance frequency spectrum of the hologram (here: the holographic decoupling structure). The limitation of the spatial depth of the representation described here can therefore be particularly suitable for representing this spatial depth well in the acceptance angle spectrum described.

The same applies to the size of the figures shown.

Such a representation is particularly well suited for a holographic representation using simple and inexpensive means as described herein.

In a further preferred embodiment of the invention, the light guide, in particular the substrate of the light guide, comprises a material which is an optical plastic and is selected from the group comprising polymethyl methacrylate (PMMA), polycarbonate, cyclic olefin polymer (COP) and/or cycloolefin Copolymers (COC) and/or the light guide, in particular the substrate of the light guide, comprises a material which is an optical glass and is selected from the group consisting of borosilicate glass, B270, N-BK7, N-SF2, P-SF68, P- SK57Q1, P-SK58A and/or P-BK7.

These materials are particularly well suited for a transparent light guide, which has good optical properties such as high transparency, homogeneity, e.g. B. in relation to the refractive index and is inexpensive and easy to manufacture. Some of the materials listed have a high refractive index compared to the environment, e.g. B. compared to air under standard conditions.

Air under standard conditions refers in particular to air according to ISO 2533, especially air at 288.15 Kelvin (K) or 15° C, an air pressure of 1013.25 hectopascals (hPa) and a relative humidity of 0 or dry air. However, a person skilled in the art can also assume the usual refractive index of about 1 for air and calculate the critical angle accordingly.

In a further preferred embodiment of the invention, the light guide structure comprises a detection arrangement, which is arranged on a side surface of the light guide structure, preferably a second side, and is set up for detecting electromagnetic radiation with at least a second spectrum from the light guide structure, the light guide structure being set up for conducting electromagnetic radiation of the second spectrum and wherein the light guide structure comprises at least one holographic coupling structure which is set up for coupling electromagnetic radiation of the second spectrum directed onto the first main surface and/or a second main surface of the light guide structure within an acceptance angle spectrum of the coupling structure into a Direction of the detection arrangement.

The light guide structure can also include one light guide, which is preferably also referred to as the first light guide, or else a second light guide. If a second light guide is included and, for example, the detection arrangement is present on this second light guide, then it can be preferred, for example, for the first light guide to be set up for electromagnetic radiation from the first light guide and the second light guide for electromagnetic radiation from the second light guide. In this case, too, it can preferably be said that the light guide structure is set up both for conducting electromagnetic radiation of the first spectrum and of the second spectrum.

A second side surface can in particular comprise a side surface opposite the first side surface.

The second spectrum can preferably correspond to the first spectrum or overlap or at least partially correspond to it. However, the second spectrum can preferably also be a different spectrum from the first spectrum, the first spectrum comprising, for example, a visible spectrum and the second spectrum comprising a near-infrared spectrum which is essentially invisible to the human eye.

The at least one holographic coupling structure is set up for coupling electromagnetic radiation of the second spectrum directed onto the first main surface and/or a second main surface of the light guide structure within an acceptance angle spectrum of the coupling structure in a direction of the detection arrangement. This preferably means that the in-coupling structure works in a manner analogous to the out-coupling structure, but in the “reverse” direction and for a second spectrum. The coupling structure therefore does not couple electromagnetic radiation out of a main surface, but through a main surface into the light guide, with the radiation being deflected at the same time in the direction of the detection arrangement, so that the electromagnetic radiation can at least partially impinge on the detection arrangement and/or be detected by it can be. The deflection and/or conduction of the electromagnetic radiation in the light guide can take place directly without further reflections and/or by multiple reflections in the light guide, preferably at an angle greater than the critical angle of the total reflection at an interface of the light guide. The acceptance angle spectrum is preferably defined as in the case of the coupling-out surface, but an angle is measured between a reference straight line or reference plane and a light beam which impinges on the coupling-in structure from outside the light guide.

The second main surface is preferably a main surface or outer surface of the light guide structure opposite the first main surface of the light guide structure.

The coupling surface preferably functions in the manner described above if the electromagnetic radiation of the second spectrum reaching the coupling surface from outside the light guide is within a specific angular range in relation to the coupling structure, to a surface comprised by the coupling structure and/or in relation to the first main surface of the light guide structure. This angle or range of angles is preferably measured using a light beam in relation to a straight line or a plane, as described in this document. The area encompassed by the in-coupling structure can relate in particular to an area within which structural elements of the in-coupling structure are arranged, for example the arrangement of modulations of the refractive index within the in-coupling structure. It can also mean the area along the areal extension of the coupling structure.

This angular range is preferably called the acceptance angle spectrum of the in-coupling structure and includes in particular the angular range for which the in-coupling hologram has the desired properties described here for the second spectrum and/or parts of the second spectrum. In particular, the acceptance angle spectrum is defined in relation to the efficiency of the holographic in-coupling structure, in particular in relation to the in-coupling efficiency, which is considered as a function of the angle range described above. This in-coupling efficiency is preferably defined in relation to the electromagnetic radiation of the second spectrum impinging on the in-coupling structure from outside the light guide, which is coupled into the light guide and reaches the detection arrangement. In this case, the efficiency can preferably assume values between 0 (eg no light is coupled in and reaches the detection arrangement) and 1 (all light is coupled in and reaches the detection arrangement). The acceptance angle spectrum of the in-coupling structure is preferably defined in that the in-coupling efficiency for the angle range covered is 0.1 or greater, more preferably 0.5 or greater.

The acceptance angle spectrum of the in-coupling structure is measured in particular in relation to the surface normal of the in-coupling structure, to the surface normal of the surface encompassed by the in-coupling structure and/or the surface normal to the first main surface of the light guide structure.

The angular spectrum can preferably be meant in the vertical direction, i.e. preferably the angular spectrum or its projection in relation to a cross-sectional plane of the light guide and/or the angular spectrum in the horizontal direction, i.e. preferably the angular spectrum or its projection in relation to a longitudinal section plane of the light guide. Depending on this, the angle is preferably measured in relation to the respective plane.

It can also be preferred to measure the acceptance angle spectrum of the coupling structure in general in relation to the aforementioned surface normal, without referring to one of the directions mentioned.

The functionality of the light guide can be increased by a light guide structure which includes a detection arrangement, e.g. B. the light guide structure can be used as a holographic operating component.

The coupling structure is preferably spaced apart from the side surface on which the detection arrangement is present. The coupling-in structure can, for example, be arranged at least partially superimposed on the decoupling structure. The coupling structure can be arranged on and/or along the first main surface or on and/or along the second main surface.

The acceptance angle spectrum of the in-coupling structure is preferably no more than 5°. In this way, it can be achieved that the beam guidance of the coupled-in electromagnetic radiation runs as desired and the coupled-in radiation essentially or partially reaches the detection arrangement, so that detection can also advantageously be carried out there without (complex) beam-shaping components.

In a further preferred embodiment of the invention, the acceptance angle spectrum of the holographic coupling structure is a maximum of 5°, with more than one holographic coupling structure being included, in particular up to five holographic coupling structures being included, with each holographic coupling structure having a different acceptance angle spectrum and/or a different reconstruction angle .

The reconstruction angle is preferably defined mutatis mutandis as in the case of the holographic outcoupling structure.

The coupling structures are preferably arranged parallel to the main surface congruently, in particular in the direction of a surface normal, as defined above one above the other.

Thus, despite a small acceptance angle spectrum of an individual coupling structure, which can advantageously be used to implement good beam guidance to the detection arrangement, light with different acceptance angle spectra can be coupled in and the efficiency can thus be increased.

The holographic coupling structures can be arranged one above the other, in particular stacked one above the other, in a so-called stack.

It can also be preferred that the in-coupling structures are arranged next to one another in a first direction from the detection arrangement in the direction of the in-coupling structure.

It may be preferred that the holographic coupling structures (whether side by side or one above the other) are in a single coupling holo gram, in particular in a so-called hologram foil, in which they were exposed together. Such a coupling hologram is preferably also referred to as a so-called multiplex hologram.

In a further preferred embodiment of the invention, the detection arrangement comprises a detector and at least one beam-shaping element arranged between the detector and the second side surface, which element is selected from the group consisting of a lens, diffuser, prism, holographic structure and/or grating.

The detector is preferably set up to generate a signal, in particular an electromagnetic signal, as a function of the incident electromagnetic radiation of the second spectrum. A detector can include, for example, a camera, a CCD camera, an infrared camera, a photodiode, an avalanche photodiode or the like.

Coupling of the coupled-in electromagnetic radiation to the detector can advantageously be optimized by a beam-shaping component.

In a further preferred embodiment of the invention, the detection arrangement comprises a detector and no additional beam-shaping element, the detector being arranged directly on the second side surface of the light guide.

Particularly in combination with at least one holographic in-coupling structure, the acceptance angle spectrum of which amounts to a maximum of 5°, it can be realized in a particularly simple and inexpensive manner that a large part of the in-coupled electromagnetic radiation reaches the detection arrangement and in particular is coupled to the detector. Electromagnetic radiation of the second spectrum can thus be detected with a large angular spectrum, particularly in combination with a plurality of coupling structures, each of which has a different acceptance angle spectrum.

In a further preferred embodiment of the invention, the light guide, detection arrangement and/or illumination arrangement are present together in a monolithic component. This results, mutatis mutandis, in the embodiments and advantages already discussed above in connection with the lighting arrangement and the light guide.

In a further preferred embodiment of the invention, the detection arrangement is connected directly to the side face of the light guide by an injection molding process. This results in the embodiments and advantages already discussed above in connection with the lighting arrangement and the light guide, which also apply mutatis mutandis in connection with the detection arrangement.

In a further preferred embodiment of the invention, the light guide is a planar light guide, in particular a cuboid light guide. This form is particularly easy and inexpensive to produce and at the same time suitable for a large number of applications and intended installation spaces.

In a further preferred embodiment of the invention, the light guide is a curved light guide. For example, the light guide can have a radius of curvature in a plane perpendicular to a main surface and/or side surface.

In this way, an individual adaptation to applications and/or installation spaces provided for the light guide can be achieved.

• - Bereitstellung eines flächigen Lichtleiters, welcher eingerichtet ist für eine Leitung elektromagnetischer Strahlung eines ersten Spektrums
• - Bereitstellung mindestens einer Beleuchtungsanordnung zur Einstrahlung einer elektromagnetischen Strahlung mit einem ersten Spektrum in den Lichtleiter, umfassend mindestens eine Lichtquelle zur Emission von elektromagnetischer Strahlung mit dem ersten Spektrum, sowie Verbinden der Beleuchtungsanordnung mit einer ersten Seitenfläche des Lichtleiters, wobei das Winkelspektrum der von der Beleuchtungsanordnung eingestrahlten und/oder von der Lichtquelle in Richtung des Lichtleiters emittierten elektromagnetischen Strahlung betragsmäßig mindestens 15°, bevorzugt mindestens 20°, stärker bevorzugt mindestens 30° und insbesondere mindestens 40° beträgt
• - Anordnung mindestens einer holographischen Auskoppelstruktur am und/oder im Lichtleiter, wobei die Auskoppelstruktur eingerichtet ist für eine Auskopplung von in der Lichtleiterstruktur zur Auskoppelstruktur geleiteten elektromagnetische Strahlung der Beleuchtungsanordnung innerhalb eines Akzeptanzwinkelspektrums der Auskoppelstruktur aus einer ersten Hauptfläche der Lichtleiterstruktur,

wobei das im Lichtleiter von einer ersten Seitenfläche zur holographischen Auskoppelstruktur geleitete Winkelspektrum der eingestrahlten elektromagnetischen Strahlung und/oder das Akzeptanzwinkelspektrum der holographischen Auskoppelstruktur betragsmäßig höchstens 5° beträgt.In a further aspect, the invention relates to a manufacturing method for a light guide structure, preferably as described here, comprising the following steps:

• - Provision of a flat light guide, which is set up for conducting electromagnetic radiation of a first spectrum
• - Provision of at least one lighting arrangement for irradiating electromagnetic radiation with a first spectrum into the light guide, comprising at least one light source for emitting electromagnetic radiation with the first spectrum, and connecting the lighting arrangement to a first side surface of the light guide, the angular spectrum of the lighting arrangement the amount of electromagnetic radiation radiated in and/or emitted by the light source in the direction of the light guide is at least 15°, preferably at least 20°, more preferably at least 30° and in particular at least 40°
• - Arrangement of at least one holographic decoupling structure on and/or in the light guide, the decoupling structure being set up for decoupling of electromagnetic radiation of the lighting arrangement guided in the light guide structure to the decoupling structure within an acceptance angle spectrum of the decoupling structure from a first main surface of the light guide structure,

wherein the guided in the light guide from a first side surface to the holographic decoupling structure angular spectrum of the irradiated electromagnetic cal radiation and/or the acceptance angle spectrum of the holographic decoupling structure is a maximum of 5°.

It is obvious to a person skilled in the art that advantages, definitions and embodiments of the device according to the invention also apply to the claimed method according to the invention.

• Verbinden der Beleuchtungsanordnung, insbesondere der Lichtquelle, mit einer ersten Seitenfläche des Lichtleiters durch ein Spritzgussverfahren.

In a preferred embodiment of the invention, the production process additionally comprises the following step:

• Connecting the lighting arrangement, in particular the light source, to a first side surface of the light guide by an injection molding process.

In a further preferred embodiment of the invention, more than one holographic decoupling structure is included, in particular up to five holographic decoupling structures are included, each holographic decoupling structure having a different acceptance angle spectrum and/or a different reconstruction angle within the angular spectrum of the irradiated by the lighting arrangement and/or by the Light source in the direction of the light guide emitted electromagnetic radiation.

1. i. durch das Verhältnis zwischen dem Winkelspektrum der eingestrahlten elektromagnetischen Strahlung und dem Überlapp des Winkelspektrums der eingestrahlten elektromagnetischen Strahlung mit dem im Lichtleiter von der Beleuchtungsanordnung zur holographischen Auskoppelstruktur geleiteten Winkelspektrum und dem Akzeptanzwinkelspektrum der Auskoppelstruktur und/oder
2. ii. durch das Verhältnis zwischen dem Frequenzspektrum der Lichtquelle und dem Überlapp des Frequenzspektrums der Lichtquelle und dem Akzeptanzfrequenzspektrum der Auskoppelstruktur.

In a further preferred embodiment of the invention, the intensity of the lighting arrangement is proportional to a basic intensity of the lighting arrangement multiplied by an inverse of the decoupling loss, which is characterized

1. i. by the ratio between the angular spectrum of the radiated electromagnetic radiation and the overlap of the angular spectrum of the radiated electromagnetic radiation with the angular spectrum conducted in the light guide from the illumination arrangement to the holographic decoupling structure and the acceptance angle spectrum of the decoupling structure and/or
2. ii. by the ratio between the frequency spectrum of the light source and the overlap of the frequency spectrum of the light source and the acceptance frequency spectrum of the outcoupling structure.

In a further aspect, the invention relates to a light guide structure produced by the method described here.

It is clear to the person skilled in the art that advantages, definitions and embodiments of the light guide structure according to the invention according to the first and second aspect and of the method according to the invention also apply to the claimed light guide structure according to this aspect.

In a further aspect, the invention relates to an operating element comprising a light guide structure as preferably described above in this document, comprising a detection arrangement, wherein the first and the second spectrum are different, wherein the decoupling structure is in particular a first decoupling structure, the decoupling structure being set up to a generation of a holographic representation of a three-dimensional operating area for the operating element and wherein the operating area for the operating element is at least partially outside the light guide structure.

The first spectrum includes, in particular, spectral ranges of visible light, and the second spectrum includes, in particular, near-infrared light.

The coupling structure and detection arrangement are preferably set up for detecting electromagnetic radiation of the second spectrum from the operating area.

In particular, the detection arrangement is set up for detection only of electromagnetic radiation of the second spectrum. If the first and second spectrum are different, it can be prevented in a simple manner that electromagnetic radiation of the first spectrum that has accidentally gotten into the detection arrangement is detected. This can be implemented, for example, by selecting a material that is suitable in relation to the first and second spectrum and/or by using a corresponding spectral filter.

Likewise, the in-coupling structure can in particular only be suitable for in-coupling electromagnetic radiation of the first spectrum and thus reduce the risk of accidental detection of electromagnetic radiation of the first spectrum.

An operating element is preferably set up to operate a system or a component and in particular includes at least one switch for input by a user. The input at the switch can preferably be achieved by light beams detected by the detection unit, which are reflected, for example, by a hand or a finger of a user. This applies in particular if a corresponding gesture is made by the user in the operating area.

The operating area can, for example, by a three-dimensional holographic representation ment of the operating area, e.g. in the form of a button, a switch or similar. An image can be displayed which graphically underscores the input that can be operated by the operating element. For example, a warning triangle that appears three-dimensional and is floating above the operating element can be displayed for operating a hazard warning light by the operating element.

In the example mentioned, the operating area is also located in the area in which the floating triangle is then recognized by a user.

The fact that the decoupling structure described above is referred to as the first decoupling structure is primarily due to the fact that further decoupling structures with other properties and/or functionalities can be included.

It is clear to the person skilled in the art that advantages, definitions and embodiments of the light guide structure according to the first and second aspect, the method according to the invention and the operating element according to the invention described below according to another aspect also apply to the claimed operating element according to this aspect.

• - eine flächige Lichtleiterstruktur umfassend mindestens einen ersten flächigen Lichtleiter
• - eine erste Beleuchtungsanordnung umfassend mindestens eine Lichtquelle zur Emission von elektromagnetischer Strahlung mit einem ersten Spektrum
• - eine Detektionsanordnung umfassend einen Detektor für eine Detektion von elektromagnetischer Strahlung mit einem zweiten Spektrum

wobei das erste und das zweite Spektrum unterschiedlich sind, wobei der erste Lichtleiter eingerichtet ist für eine Leitung elektromagnetischer Strahlung des ersten und zweiten Spektrums, wobei die erste Beleuchtungsanordnung an einer ersten Seitenfläche des ersten Lichtleiters angeordnet vorliegt und eingerichtet ist für die Einkopplung der emittierten elektromagnetischen Strahlung des ersten Spektrums in den ersten Lichtleiter, wobei die Detektionsanordnung an einer Seitenfläche der Lichtleiterstruktur angeordnet vorliegt und eingerichtet ist für eine Detektion von in die Lichtleiterstruktur eingekoppelter elektromagnetischen Strahlung des zweiten Spektrums, wobei die Lichtleiterstruktur mindestens eines von der ersten Seitenfläche beabstandete erste holographische Auskoppelstruktur und eine von der Seitenfläche beabstandete holographische Einkoppelstruktur aufweist, wobei die erste Auskoppelstruktur eingerichtet ist für eine Auskopplung der eingekoppelten elektromagnetischen Strahlung der ersten Beleuchtungsanordnung aus einer ersten Hauptfläche der Lichtleiterstruktur zu einer Erzeugung einer holographischen Darstellung eines dreidimensionalen Bedienbereichs zum Bedienelement, wobei der Bedienbereich zum Bedienelement zumindest teilweise außerhalb der Lichtleiterstruktur liegt und wobei die Einkoppelstruktur eingerichtet ist für eine Einkopplung elektromagnetischer Strahlung mit dem zweiten Spektrum aus dem Bedienbereich in die Lichtleiterstruktur in eine Richtung der Detektionsanordnung.In a further aspect, the invention relates to an operating element comprising:

• - A flat light guide structure comprising at least one first flat light guide
• - A first lighting arrangement comprising at least one light source for emitting electromagnetic radiation with a first spectrum
• - A detection arrangement comprising a detector for detecting electromagnetic radiation with a second spectrum

wherein the first and the second spectrum are different, wherein the first light guide is set up for conducting electromagnetic radiation of the first and second spectrum, wherein the first lighting arrangement is arranged on a first side face of the first light guide and is set up for coupling in the emitted electromagnetic radiation of the first spectrum into the first light guide, the detection arrangement being arranged on a side face of the light guide structure and being set up for detecting electromagnetic radiation of the second spectrum coupled into the light guide structure, the light guide structure having at least one first holographic decoupling structure spaced apart from the first side face and a having a holographic coupling-in structure spaced apart from the side surface, the first coupling-out structure being set up for coupling out the coupled-in electromagnetic radiation ng the first lighting arrangement from a first main surface of the light guide structure to generate a holographic representation of a three-dimensional operating area for the operating element, wherein the operating area for the operating element is at least partially outside the light guide structure and wherein the coupling structure is set up for coupling electromagnetic radiation with the second spectrum from the Operating area in the light guide structure in one direction of the detection arrangement.

It is clear to the person skilled in the art that advantages, definitions and embodiments of the light guide structure according to the first and second aspect, the method according to the invention and the operating element according to the invention described above according to another aspect also apply to the claimed operating element according to this aspect.

The properties described for the above light guide structure in relation to the angle spectra and/or acceptance angle spectra for the lighting arrangement, the light guide, the decoupling structure and/or the incoupling structure may or may not be used. If these do not come into play, no special properties are preferably included with regard to the angle spectra and acceptance angle spectra.

In a preferred embodiment of the invention, the detection arrangement is arranged on the second side surface of the first light guide. In this case, the decoupling structure and the coupling structure can preferably be arranged one above the other in relation to a direction perpendicular to the first main surface and/or next to one another in a direction from the side surface to the coupling or decoupling structure in the first light guide. They are preferably set up in such a way that the functionality of the respective other structure is essentially not impaired. If they are arranged one above the other, the structures can be transparent, for example, to the respective other spectrum of the electromagnetic radiation.

In this embodiment, for example, a single light guide can be included.

As a result, an operating element can be provided which consists of a particularly small number of elements and is particularly simple to manufacture due to the use of only one light guide. Furthermore, space for the operating element can preferably be saved as a result.

In a further preferred embodiment of the invention, the light conductor structure has a second flat light guide, which is arranged parallel to the first flat light guide on a side of the first flat light guide opposite the first main surface and is set up for light transmission of electromagnetic radiation of the second spectrum, the detection arrangement is arranged on a first side surface of the second light guide and the coupling structure is surrounded by the second light guide and the first decoupling structure is surrounded by the first light guide and is transparent to electromagnetic radiation of the second spectrum between the first main surface of the light guide structure and the coupling structure.

The second light guide, which is set up for light conduction of electromagnetic radiation of the second spectrum, preferably has the properties mentioned for the first light guide, mutatis mutandis, for the second spectrum.

The second flat light guide is arranged parallel to the first flat light guide on a side opposite the first main surface, in particular on a second main surface of the first flat light guide. The first main surface of the first light guide preferably forms the first main surface of the first light guide structure.

This preferably results in two inner main surfaces of the light guides in relation to the light guide structure, with that of the first light guide preferably comprising its second main surface and the inner main surface of the second light guide being preferably referred to as its second main surface. The first main surface of the first light guide, which is on the outside in relation to the light guide structure, then preferably forms the first main surface of the light guide structure, and the first main surface of the second light guide, which is also preferably on the outside in relation to the light guide structure, preferably forms the second main surface of the second light guide structure.

In this case, the detection arrangement is arranged on a first side surface of the second light guide and the coupling structure is encompassed by the second light guide. In particular, the radiation of the second spectrum from the operating area can be coupled into the second light guide and guided through it to the first side surface of the second light guide, where the detection arrangement is located. The first decoupling structure, which is encompassed by the first light guide, should therefore be transparent to electromagnetic radiation of the second spectrum between the first main surface of the light guide structure and the coupling structure, so that the radiation of the second spectrum from the operating area can pass through the decoupling structure and reach the coupling structure.

The first and second side surfaces of the second light guide can be defined analogously to the first and second side surfaces of the first light guide. The definition can preferably be based on a convention. In particular, side faces of the first and second light guides located on the same side of the light guide structure can be designated the same. However, it can preferably also be arbitrarily determined which is the first and which is the second side surface of the second light guide, for example also exactly the opposite of the determination for the first light guide.

This embodiment makes it possible to provide a particularly simple and well-functioning control element, in which the display of the control element and the detection can be implemented with simple means and with little interference and can be spatially separated from one another.

In a further preferred embodiment of the invention, a region is included between the first light guide and the second light guide, which is suitable for enabling conduction of electromagnetic radiation of the first and/or second spectrum in the first and second light guide by total internal reflection and preferably a lower refractive index than that has light guide.

In this case, the area is preferably transparent to electromagnetic radiation of the second spectrum.

As an alternative to an area with a lower refractive index than the light guide, the area can preferably have reflective and/or diffractive properties for the spectrum to be guided in the respective light guide at an interface adjacent to this light guide.

For example, the area can include air under standard conditions and/or a solid material that meets the requirements, for example a special adhesive for connecting the two light guides to one another.

In a further preferred embodiment of the invention, only one light guide is included, with a region being included on a second main surface of the first light guide, which is suitable for enabling conduction of electromagnetic radiation of the first and/or second spectrum in the first light guide by total internal reflection and preferably has a lower refractive index than the light guide.

This is a preferred embodiment when the light guide is connected to a carrier along the second main surface, for example to a center console of a dashboard in a vehicle.

In a further preferred embodiment of the invention, the operating element comprises a second lighting arrangement comprising at least one second light source for emitting electromagnetic radiation with the second spectrum, the second lighting arrangement being set up for illuminating the operating area with electromagnetic radiation of the second spectrum.

While possible embodiments that do not include a second lighting arrangement for emitting electromagnetic radiation with the second spectrum enable detection by residual and/or ambient light, which includes electromagnetic radiation of the second spectrum, active lighting of the operating area is provided in embodiments with a second lighting arrangement. to move from an object, e.g. B. from a hand of a user to detect reflected radiation and determine so an operation if necessary.

In this case, the lighting arrangement is preferably arranged, aligned and/or provided with appropriate beam-shaping components in order to enable the operating area to be illuminated.

In this embodiment, one or two light guides may be included. If two light guides are included, the detection arrangement is preferably present on the first side face of the second light guide. In this case, in particular, the coupling structure is encompassed by the second light guide.

The first decoupling structure is preferably encompassed by the first light guide and is transparent to electromagnetic radiation of the second spectrum between the first main surface of the light guide structure and the incoupling structure.

In a further preferred embodiment of the invention, the second lighting arrangement is arranged on the side of the light guide structure opposite the first main surface of the light guide structure on a second main surface of the light guide structure, the holographic coupling-in structure and/or the first holographic coupling-out structure in a direction from the second lighting arrangement to the first main surface of the light guide structure is transparent for the electromagnetic radiation with the second spectrum.

In this preferred variant, the second lighting arrangement is preferably arranged “beneath” the light guide structure, on the side of the second main surface, while the operating area is arranged on the other side of the light guide structure, on the side of the first main surface. As a result of the features mentioned, the light guide structure is preferably irradiated by the lighting arrangement in the direction of the operating area, in particular including the coupling-in and/or the first coupling-out structure. At least the first decoupling structure is preferably also irradiated by any light reflected from the operating area, with this being deflected by the coupling structure in particular in the direction of the detector.

For example, the second lighting arrangement, operating area, in-coupling structure and/or out-coupling structure can be arranged relative to one another in such a way that when the operating area is illuminated, the in-coupling structure does not have to be illuminated and it accordingly does not have to be transparent to the second spectrum (example oblique lighting). However, a corresponding angular selectivity can also be provided for the in-coupling structure, so that only electromagnetic radiation of the second spectrum from the operating area, but not radiation that comes directly from the second lighting arrangement, is diffracted by the in-coupling structure. This can then advantageously be transmitted through the coupling structure.

In a further preferred embodiment of the invention, the control element comprises the second planar light guide, the second lighting arrangement being arranged on the second side surface of the first light guide for coupling electromagnetic radiation of the second spectrum into the first light guide, the first light guide having a second holographic decoupling structure which is set up for decoupling the coupled electromagnetic radiation of the second lighting arrangement from the first main surface of the light guide structure in the direction of the operating area and wherein the second decoupling structure is transparent to electromagnetic radiation of the second spectrum between the first main surface of the light guide structure and the coupling structure.

In this case, the detection arrangement is preferably arranged on a first side surface of the second light guide and the coupling structure is encompassed by the second light guide. Furthermore, the first decoupling structure is preferably from the first The light guide includes and is transparent to electromagnetic radiation of the second spectrum between the first main surface of the light guide structure and the coupling structure.

In a further preferred embodiment of the invention, the control element comprises the second planar light guide, the second lighting arrangement being arranged on the second side face of the second light guide for coupling electromagnetic radiation of the second spectrum into the second light guide, the second light guide having a second holographic decoupling structure , which is set up for decoupling the coupled-in electromagnetic radiation of the second lighting arrangement from the first main surface of the light guide structure in the direction of the operating area.

In this case, the detection arrangement is preferably arranged on a first side surface of the second light guide and the coupling structure is encompassed by the second light guide. Furthermore, the first coupling-out structure is preferably surrounded by the first light guide and is transparent to electromagnetic radiation of the second spectrum between the first main surface of the light-guide structure and the coupling-in structure.

The second decoupling structure preferably works, mutatis mutandis, in the same way as the first decoupling structure, but for the electromagnetic radiation of the second spectrum and/or the second illumination arrangement.

The detection arrangement can preferably be present on the second side surface of the first light guide, in which case the coupling structure is then preferably surrounded by the first light guide, or on the first side surface of the second light guide, in which case the coupling structure is preferably surrounded by the second light guide.

If the in-coupling structure is encompassed by the first light guide, the in-coupling and out-coupling structure are preferably set up so as not to impair the functionality of the respective other structure. This can be implemented, for example, through transparency for the respective spectrum, a suitable acceptance angle spectrum and/or a suitable acceptance frequency spectrum of the respective structure. For example, the first decoupling structure could be transparent to the electromagnetic radiation of the second spectrum, so that the decoupling of this radiation is not impaired by the second decoupling structure.

In a further preferred embodiment of the invention, the second light guide is essentially opaque to electromagnetic radiation of the first spectrum. It can thus be implemented particularly advantageously that the operating element can be integrated into the interior in an optically unobtrusive manner if the second light guide has a correspondingly suitable color. For example, the second light guide could appear black and thus allow adaptation to a black interior, for example in a vehicle. In addition, it can be particularly effectively prevented in this way that electromagnetic radiation of the first spectrum is inadvertently detected by a detection arrangement present on the second light guide.

In a further preferred embodiment of the invention, a screen element, in particular a film, is included between the first and second light guide, which is essentially opaque to electromagnetic radiation of the first spectrum and transparent to electromagnetic radiation of the second spectrum. In this way, an effect similar to that in the previous embodiment can be achieved, but in a particularly simple and inexpensive manner.

In a further preferred embodiment of the invention, the screen element has a lower refractive index than the light guides.

The conduction of the respective electromagnetic radiation in the light guide can thus be implemented in a particularly simple manner.

In a further preferred embodiment of the invention, the holographic representation of the operating area for the operating element includes a three-dimensional representation of the three-dimensional operating area by a real and/or virtual holographic image.

In particular, this is a real image that is created outside of the light guide and represents a free-floating, three-dimensional representation of the operating area. In this way, easier operation with a high level of operating comfort can be implemented.

However, it can also be an “in-plane” representation.

If the control element is used in a car, for example, safety can be increased since it can be operated particularly intuitively and the operator's attention can be channeled in a targeted manner.

If the operating element is used in public space, hygiene can be improved, for example, because no surfaces are touched and thus the transmission of germs over such an area is prevented.

In a further preferred embodiment of the invention, a first spectrum is in a first wavelength range predominantly between 380 nm and 750 nm, preferably between 440 nm and 660 nm and/or a second spectrum in a second wavelength range above 750 nm, preferably between 740 nm and 3 micrometers (µm), more preferably between 750 nm and 1.4 µm and especially between 800 nm and 900 nm.

The second spectrum includes, in particular, near-infrared light.

It has been found that particularly good visibility and operability result for the aforementioned visible spectra and particularly good detectability and thus operational safety for the aforementioned near-infrared spectra. In addition, there is a large number of materials that are particularly well suited for both of the spectra mentioned. Detection in the near-infrared particularly allows detection of electromagnetic light that is not visible to humans and therefore not disruptive.

Another preferred embodiment of the invention also includes a control device, the detection arrangement and the control device being set up to recognize an event in the operating area for the operating element as an operating gesture and to output a corresponding control signal when an event in the operating area is recognized as an operating gesture.

A control device is, in particular, at least one integrated circuit, e.g. B. at least one microprocessor, at least one processor or processor unit, at least one CPU, at least one computer and / or at least one computer. A control device can, for example, comprise an application-specific integrated circuit (ASIC), a programmable logic device (PLD) or a field programmable gate array (FPGA). Furthermore, components known to the person skilled in the art in this context, such as at least one electronic memory, an integrated circuit, at least one digital-to-analog converter, at least one analog-to-digital converter and/or at least one amplifier can be included.

The detection arrangement and control device are set up to recognize an event in the operating area for the operating element as an operating gesture and to output a corresponding control signal when an event is recognized as an operating gesture in the operating area.

For this purpose, the detection arrangement should carry out suitable detections of electromagnetic radiation of the second spectrum, which can subsequently be used to recognize an operating gesture. For example, the detection arrangement can create a chronological sequence of images from the operating area, on which an operating gesture can be recognized. These images can be converted into electronic signals, for example, and then fed to the control device.

The control device preferably has suitable algorithms for object recognition and/or gesture recognition, by which z. B. an operating gesture visible on the images created by the detection arrangement can be recognized. Algorithms can be used here, for example, which use the means of so-called artificial intelligence, for example artificial neural networks and/or machine learning can be used to recognize operating gestures.

The control signal is in particular an electronic control signal which can control further components which have a corresponding electronic signal input.

In this way, even complex technical components, e.g. of a vehicle, can be operated intuitively and safely using the operating component.

In a further preferred embodiment of the invention, the event is recognized as an operating gesture in the operating area by image recognition and/or a distance measurement.

Suitable image recognition algorithms can preferably be used for the image recognition. B. on the basis of comparative 3D models, recordings from different angles, which in particular use edge detection or work with components. Such algorithms can, for example, be trained on the basis of a large number (e.g. at least one million) of images using machine learning.

A distance measurement includes in particular an (electro)optical distance measurement. Such an (electro)optical distance measurement can, for example, be based on (optical) transit time measurement, phase modulation, interferometry, triangulation, time-of-flight (TOF) measurement or TOF camera and/or light detection and ranging or light imaging detection and ranging (LIDAR). In this case, preferably lasers, in particular pulsed lasers emitting electromagnetic radiation of the second spectrum can be used.

In a further preferred embodiment of the invention, the control device comprises an image recognition unit and the detection arrangement comprises an infrared camera.

As a result, an image or gesture recognition, which takes place through recordings in the (near) infrared range, can be recognized particularly well.

An image recognition unit can include, for example, a processor that is particularly suitable for image recognition (eg, particularly powerful) and/or corresponding algorithms on the control device.

In a further preferred embodiment of the invention, the first and/or second light source is selected from the group of LEDs and/or lasers.

These light sources are particularly suitable for use in connection with holograms and at the same time are simple, compact, require little maintenance and are inexpensive.

Description of the invention:

• 1 zeigt eine Lichtleiterstruktur mit einem einzigen Lichtleiter in einer perspektivischen Ansicht.
• 2A zeigt (ausschnittsweise) die Lichtleiterstruktur mit einem einzigen Lichtleiter in einer seitlichen Ansicht.
• 2B zeigt einen Ausschnitt der in 2A gezeigten Lichtleiterstruktur
• 3 zeigt die Beleuchtungsstärke der Hologrammfläche.
• 4 zeigt die Lichtstärke der Hologrammfläche.
• 5 zeigt das Multiplexing von Hologrammen für verschiedene Akzeptanzwinkelspektren.
• 6 zeigt eine weitere Seitenansicht einer Lichteiterstruktur mit einem Lichtleiter.
• 7 zeigt eine weitere vergrößerte Seitenansicht der Lichtleiterstruktur mit einem Lichtleiter ähnlich 2B.
• 8 zeigt ein Bedienelement umfassend eine Lichtleiterstruktur mit zwei Lichtleitern.
• 9 zeigt ein Bedienelement mit einem Lichtleiter und nur einer Beleuchtungsanordnung für das erste Spektrum.
• 10 zeigt ein Bedienelement mit einem Lichtleiter, einer Beleuchtungsanordnung für das erste Spektrum und einer Beleuchtungsanordnung für das zweite Spektrum.
• 11 zeigt ein Bedienelement mit zwei Lichtleitern und nur einer Beleuchtungsanordnung für das erste Spektrum.
• 12 zeigt ein Bedienelement mit zwei Lichtleitern, einer Beleuchtungsanordnung für das erste Spektrum und einer Beleuchtungsanordnung des zweiten Spektrums unterhalb des zweiten Lichtleiters.
• 13 zeigt ein Bedienelement mit zwei Lichtleitern, einer Beleuchtungsanordnung für das erste Spektrum und einer Beleuchtungsanordnung des zweiten Spektrums an der zweiten Seitenfläche des ersten Lichtleiters.
• 14 zeigt ein Bedienelement mit zwei Lichtleitern, einer Beleuchtungsanordnung für das erste Spektrum und einer Beleuchtungsanordnung des zweiten Spektrums an der zweiten Seitenfläche des zweiten Lichtleiters.

The invention is to be explained below with reference to further figures and examples. The examples and figures serve to illustrate preferred embodiments of the invention without restricting them.

• 1 shows a light guide structure with a single light guide in a perspective view.
• 2A shows (partially) the light guide structure with a single light guide in a side view.
• 2 B shows a section of the in 2A shown light guide structure
• 3 shows the illuminance of the hologram surface.
• 4 shows the luminous intensity of the hologram surface.
• 5 shows the multiplexing of holograms for different acceptance angle spectra.
• 6 Figure 12 shows another side view of a light guide structure with a light guide.
• 7 Figure 12 shows another enlarged side view of the light guide structure with a light guide similar 2 B .
• 8th shows a control element comprising a light guide structure with two light guides.
• 9 shows a control element with a light guide and only one lighting arrangement for the first spectrum.
• 10 shows a control element with a light guide, an illumination arrangement for the first spectrum and an illumination arrangement for the second spectrum.
• 11 shows a control element with two light guides and only one lighting arrangement for the first spectrum.
• 12 shows a control element with two light guides, an illumination arrangement for the first spectrum and an illumination arrangement for the second spectrum below the second light guide.
• 13 shows a control element with two light guides, an illumination arrangement for the first spectrum and an illumination arrangement for the second spectrum on the second side surface of the first light guide.
• 14 shows a control element with two light guides, an illumination arrangement for the first spectrum and an illumination arrangement for the second spectrum on the second side surface of the second light guide.

1 shows a light guide structure 1 comprising a planar light guide 5 according to a first or second aspect of the invention in a perspective view. The two-dimensionality is mainly due to the first main surface 8 of the light guide and the second main surface (underneath and not directly visible, indicated by dashed lines). The side faces perpendicular to the main face comprise two long side faces, one bearing the reference 10, the other not visible and indicated only by dashed lines. In addition, two short side surfaces are included, the side surface on the right in the image cannot be seen directly due to the perspective view and is only indicated by dashed lines, the side surface on the left in the illustration is the first side surface 6 of the light guide in the present example. However, prior to the attachment of the lighting arrangement for the first spectrum 2 , this definition is purely a convention and is preferably only defined when the lighting arrangement for the first spectrum 2 is attached. In the present case, the lighting arrangement for the first spectrum 2 consists simply of a light source 3, which is located on the first side surface 6 without additional beam-shaping components. In the present case, the holographic decoupling structure 7 is arranged on the first main surface 8 and is at a distance from the first side surface 6 .

The electromagnetic radiation 9 radiated into the light guide here corresponds in part simply to the electromagnetic radiation emitted by the light source in the direction of the light guide, since no beam-shaping component is used. Depending on the angle of incidence on one of the boundary surfaces of the light guide 5 (e.g. long side surface 10), the electromagnetic radiation 9 radiated into the light guide is guided or not. In relation to the direction of radiation (the angle), the light guided in the light guide 5 essentially corresponds to the angular spectrum 11 guided by the lighting arrangement to the holographic decoupling structure. This light can then be diffracted by the holographic decoupling structure 7 and thus from the first main surface 8 of the light guide 5 be coupled out, which is also the first main surface of the light guide structure 1 in the present case.

If more than one light source 3 is used, these can be arranged next to one another, in particular along the first side face 6 . This means in particular along the first side face along its extension from the first adjoining side face (here: long side face 10) to the second adjoining side face (here “rear” long side face).

2A shows the light guide 5 in a side view or cross-sectional view. The light guide is shown somewhat shortened here; a middle section between the lighting arrangement and the decoupling structure 7 is preferably not shown. The light source 3 of the lighting arrangement is shown greatly enlarged here, but it can preferably also be a true-to-scale representation. The electromagnetic radiation 19 emitted by the light source in the direction of the light guide is only partially radiated into the light guide 9. Of this radiated radiation 9, in turn, only a portion is conducted through the light guide to the decoupling structure 11. This line can take a direct route from the lighting arrangement 3 track to the decoupling structure 7 (e.g.: light beam emphasized by a dotted line with reference number 11) or on the way of single or multiple total reflection within the light guide 5 (e.g.: light beam emphasized by a broken line with reference numbers 11 and 12). Incoming light rays 9 cannot reach the decoupling structure either, because they either leave the light guide before reaching the decoupling structure 7 or radiate past it through the light guide without hitting the decoupling structure (light rays 18).

2A also contains a representation to clarify the (acceptance) angle spectrum. The light beam 11 guided in the light guide from the illumination arrangement to the decoupling structure, which impinges as a light beam on the decoupling surface 12, assumes an angle 16 with the reference line 4 in the cross-sectional plane shown. The reference line 4 in turn is a straight line or surface normal 14 perpendicular to the surface of the holographic decoupling structure 7. If this angle 16 is within the (preferably horizontal) acceptance angle spectrum of the holographic decoupling structure 7, the light beam is diffracted by the decoupling structure 7 and decoupled from the first main surface 8 . When showing in relation to 2A the acceptance angle spectrum is measured directly in relation to the surface normal to the decoupling structure 14 (here: reference line 4).

2 B shows a section of the light guide shown in FIG. 2A. Here, however, the reference line for the acceptance angle spectrum is not the surface normal to the decoupling structure 14, but the reconstruction angle 20. If the light beam 12 impinging on the decoupling structure lies within the acceptance angle spectrum around this reconstruction angle 20, the light beam 12 is diffracted by the holographic decoupling structure 7 and out of the light guide decoupled.

As well as 2A as well as 2 B illustrate the (acceptance) angle spectrum in the horizontal direction, i.e. (acceptance) angle spectrum in relation to a longitudinal sectional plane of the light guide or its projection in relation to the longitudinal sectional plane of the light guide

3 shows a simulation of the spatial distribution of the illuminance of the holographic decoupling structure in a top view in lux (Ix) for the light guide structure. The Lux unit of measure is preferably defined as the photometric illumination produced by a luminous flux of 1 lumen (Im) when evenly distributed over an area of 1 square meter.

4 shows for the light guide structure a simulation of the distribution of the light intensity of the illuminated holographic decoupling surface as a function of the angular spectrum of the illumination of the decoupling surface in candelas. This preferably corresponds to the angular spectrum of the electromagnetic radiation radiated in by the illumination arrangement and/or the angular spectrum of the radiated electromagnetic radiation conducted in the light guide from the illumination arrangement to the holographic decoupling structure. The horizontal angle spectrum is shown in the vertical direction and the vertical angle spectrum in the horizontal direction. The luminous intensity preferably indicates the luminous flux related to the solid angle. Its SI unit is the candela (cd). Luminous flux is preferably photometric Quantity that specifies the light emitted by a light source per unit of time that is perceptible to the human eye. In addition to the physical (radiometric) radiation power, it preferably takes into account the sensitivity of the human eye. It is given in the unit of measurement, lumen (Im). The light intensity is preferably defined by dΦ _V /dΩ, where dΩ preferably describes an infinitesimal solid angle element and dΦ _V describes the luminous flux component in the solid angle element dΩ. The angular spectrum (and the degree of collimation) can be determined from the representation of the luminous intensity. A center of gravity angle and an RMS radius are determined from this data for evaluation.

In the simulation, a simple light guide structure according to the first or second aspect was simulated without beam-shaping components in the lighting arrangement. A focus angle of the illumination of the holographic decoupling structure in the vertical direction of approximately 68° is found. If the reconstruction angle of the holographic decoupling structure is selected accordingly, the quantity of light decoupled can be maximized around this reconstruction angle for a given acceptance angle spectrum while at the same time limiting the acceptance angle spectrum in order to improve the quality of the holographic representation. It can also be seen that the angular spectrum of the illumination of the decoupling surface is at least 15° in the vertical direction and the angle of gravity, ie at both higher and lower angles around the angle of gravity.

5 Figure 12 shows a reconstruction angle multiplexed holographic light guide structure. The left figure of 6 again shows the distribution of the luminous intensity of the illuminated holographic decoupling surface as a function of the angle spectrum of the illumination of the decoupling surface. The dashed lines show the acceptance angle spectrum in the horizontal direction (vertical lines) and vertical direction (horizontal lines).

In the example shown, the holographic decoupling structures each have a different horizontal reconstruction angle. This is in the right figure of the 6 apparent. The decoupling efficiencies (on a scale from 0 to 1) for six holographic decoupling structures are shown here, which have a reconstruction angle shifted by approx. 2° between a horizontal angle of -70° and -60°. The width of the outcoupling efficiency of the individual outcoupling structures distributed around the reconstruction angle is preferably given by the acceptance angle spectrum (or caused by the size of the refractive index modulation), which is approximately 3° in the present case. This embodiment allows a broader angular spectrum to be decoupled (here, for example, from about -58° to about -72°), which results, for example, from a light source in the light guide that is applied directly to the side surface of the light guide without beam-shaping components. At the same time, a high-quality holographic light function can be generated due to the low acceptance angle spectrum of the individual decoupling structure. In this case, all decoupling structures preferably show the same motif, for example an operating element.

6 shows similar to 1 a light guide structure with a light guide 5, in which the illumination arrangement comprises light source 3 and beam-shaping component 13. These are attached directly to the first side surface of the light guide 5, which is also referred to as the coupling surface 15. The components of the lighting arrangement, that is to say the light source 3 and the beam-shaping component 15, preferably have an ideally adapted and space-saving design. In the present case, these components are flat, for example, and are dimensioned to match the side surface/coupling surface 15 . After assembly, the components of the lighting arrangement can form a monolithic component with the light guide 5 . The beam-shaping component includes in particular a simple lens for collimation. In this case, the light emitted by the light source 3 in the direction of the light guide will preferably have a relatively large angular spectrum of at least 15, more preferably at least 20°, even more preferably at least 30° or even at least 40°, but after collimation by the beam-shaping component 15, the angle spectrum of the angle spectrum irradiated by the lighting arrangement can be significantly lower. Ensuring the quality of the holographic light function generated by decoupling, here the real image of the three-dimensional operating area 17 symbolically represented by a star, is additionally achieved here by the low acceptance angle spectrum of the holographic decoupling structure 7, in particular under the condition that the decoupled frequency spectrum is limited as described in this document.

This multi-level "filtering" of the angular spectrum to increase the quality of the holographic light function is also in 8th apparent. 8th Figure 1 shows an enlarged side view of the light guide structure 7 is shown, in which a central part of the light guide between the coupling-in surface 15 and the holographic coupling-out structure 7 has been cut out in order to be able to show the essential parts. A first “filtering” of the large angular spectrum 19, which is emitted by the light source in the direction of the light guide, takes place through the beam-shaping component 13. The light 9 that is then radiated into the light guide by the lighting arrangement already has a significantly smaller angular spectrum. As the next possible filter stage (if necessary), only a portion of this angular spectrum is routed 11 from the illumination arrangement to the holographic decoupling structure 7 in the light guide 5. Finally, the acceptance angle spectrum of the holographic decoupling structure 7 can be significantly smaller again.

In 8th an operating element is shown having a light guide structure 1 according to a further aspect of the invention. A light guide structure according to the first or second aspect can be used here. Here, a first light guide 5 for a first spectrum and a second light guide for a second spectrum 21 are included, between which there is a diaphragm element 35 which has a lower refractive index than the light guides 5 and 21 and which is preferably transparent to light through the upper one Light guide 5 is visible and can thus determine the optics of the control element from the user's point of view. The first light guide 5 is used for displaying the operating area 17, which can be located hovering above the first light guide 5 from the viewer's point of view. The second light guide 21 is used to detect electromagnetic radiation of the second spectrum from the operating area 27 . For this purpose, a light source 3 of the lighting arrangement is located on the first side face of the first light guide 5 . This couples radiation 31 into the first light guide 5 . This is at least partially decoupled by the first holographic decoupling surface 7 and thus ensures a holographic representation of the operating area 17.

In this embodiment, a light source of an illumination arrangement for the second spectrum 23 is accommodated below the second main surface 24 of the light guide structure below the second light guide 21 . The second spectrum preferably includes near-infrared light that is not visible to the eye. This light preferably illuminates 37 the operating area with electromagnetic radiation of the second spectrum. If an operating gesture 39 now takes place in the operating area, for example by a user's finger, part 27 of this light is reflected back and can be coupled 29 through the coupling structure 25 into the second light guide 21 in the direction of the detection arrangement.

9 until 14 show different possible embodiments of the operating element according to one aspect of the invention.

The embodiment according to 9 shows a control element with a light guide structure comprising only the first light guide. The illumination arrangement for the first spectrum 2 in the form of a light source (not shown) is arranged on a first side surface of the first light guide. This couples radiation of the first spectrum into the light guide, which is then coupled out by the first holographic coupling-out structure 7 . A three-dimensional, holographic representation of an operating area 17 is generated by the emitted radiation. In the embodiment shown, no illumination arrangement for electromagnetic radiation of the second spectrum is used. Rather, an operating gesture 39 can be detected by electromagnetic radiation of the second spectrum coming from a finger, for example, which radiation is fed from ambient light, for example. The electromagnetic radiation of the second spectrum 27 coming from the operating area can then be coupled 29 by a coupling structure 25 into the light guide in the direction of the detection arrangement 41. The detection arrangement 41 can be an infrared camera, for example, which detects the finger in the operating area and thus the operating gesture 39.

10 shows an otherwise consistent embodiment 11 , which, however, includes an active illumination of the operating area 37 by an illumination arrangement for electromagnetic radiation of the second spectrum 23 . The emitted beams can, for example, pass through the coupling structure 25 by a corresponding adjustment of the acceptance angle spectrum of the latter. Likewise, the first decoupling structure 7 is transparent for these illumination beams 37 .

11 shows an embodiment with two light guides 5 and 21, but only one lighting arrangement 2 for the first spectrum. The coupling structure 25 is located here in the second light guide 21, which couples the electromagnetic radiation of the second spectrum from the operating area 27 into the second light guide 21. The detection arrangement 41 is located on a first side surface of the second light guide. It can be seen here that the definition of which is the first and which is the second side surface can be arbitrary and the first side surface of the first light guide 5 and the first side surface of the second light guide 21 do not have to be on the “same side”.

12 also shows an embodiment with two light guides 5 and 21 and a second Lighting arrangement 23 for illuminating the operating area 37 with the second spectrum. The second lighting arrangement 23 is located on the side of the light guide structure 1 opposite the first main surface 8 of the light guide structure 1 on a second main surface 24 of the light guide structure and shines through both light guides 21 and 5 as well as the coupling 25 and decoupling structures 7 arranged there done by appropriate tuning of the acceptance angle spectra and/or the acceptance frequency spectra. Otherwise, this embodiment functions essentially like the embodiment according to FIG 11 .

13 1 shows an embodiment with two light guides 5 and 21 and a second lighting arrangement 23 for illuminating the operating area 37 with the second spectrum. In the example shown, this lighting arrangement 23 is arranged on the second side surface of the first light guide 5 . The light of this lighting arrangement 23 is partially coupled into the light guide 5 and coupled out by a second decoupling structure 43 from the first main surface of the light guide structure in the direction of the operating area. In this example, the first holographic decoupling structure 7 must be transparent for the second spectrum, which is decoupled by the second decoupling structure 43 located under the first decoupling structure 7, for example by adapting the acceptance angle and/or frequency spectrum. The arrangement could of course also be reversed, that is, the second decoupling structure 43 would have to be transparent for the light decoupled from the first decoupling structure 7 . In a similar way, the two decoupling structures in the present example must be transparent for the electromagnetic radiation of the second spectrum from the operating area 27 .

14 12 shows an embodiment in which the second lighting arrangement 23 is present on the second side of the second light guide 21. FIG. The second decoupling structure 43 is therefore also arranged on/in the second light guide 23 here. Therefore, the first decoupling structure 7 must be transparent for the illumination of the operating area 37 with radiation of the second spectrum, and both the first 7 and the second decoupling structure 43 must be transparent for light of the second spectrum from the operating area 27 . Of course, the arrangement of the second decoupling structure 43 above the incoupling structure 25 is exemplary; the arrangement could also be reversed, with that of the incoupling structure 25 above the second decoupling structure 43.

Reference List

1

light guide structure

2

Illumination arrangement for the first spectrum

3

Light source for first spectrum

4

reference line

5

(First) light guide

6

First face

7

(First) holographic decoupling structure

8th

First main surface of the light guide

9

Electromagnetic radiation (of the first spectrum) radiated into the light guide

10

Long side face

11

Angle spectrum of the radiated electromagnetic radiation guided in the light guide to the holographic decoupling structure

12

Light incident on the decoupling surface

13

Beam shaping component

14

Surface normal to the decoupling structure

15

coupling surface

16

Angle of the light beam hitting the decoupling surface

17

Real image of a three-dimensional operating area

18

Electromagnetic radiation radiated into the light guide, which does not hit the decoupling structure

19

Electromagnetic radiation emitted by the light source in the direction of the light guide

20

reconstruction angle

21

Second light guide

22

Angle between the reconstruction angle and the light beam impinging on the outcoupling surface

23

Illumination arrangement for second spectrum

24

Second major surface of the light guide structure

25

Holographic launch structure

27

Electromagnetic radiation with the second spectrum from the operating area

29

Electromagnetic radiation of the second spectrum coupled into the light guide structure in the direction of the detection arrangement

31

Electromagnetic radiation of the first spectrum coupled into the first light guide

33

Decoupled electromagnetic radiation of the first lighting arrangement for generating the holographic representation of the three-dimensional operating area

35

aperture element

37

Illumination of the operating area with electromagnetic radiation of the second spectrum

39

Operating gesture (finger of a user)

41

detection arrangement

43

Second holographic decoupling structure

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102016117969 A1 [0003]

Claims (17)

Light guide structure (1) for illumination, detection and/or holographic display, comprising: - At least one flat light guide (5), which is set up for conducting electromagnetic radiation of at least one first spectrum - At least one arranged on a first side surface of the light guide lighting arrangement (2) comprising at least one light source (3) for emitting electromagnetic radiation with a first spectrum for irradiating electromagnetic radiation with the first spectrum in the light guide - at least one holographic decoupling structure (7), preferably spaced apart from the first side surface (6), which is set up for decoupling guided in the light guide structure electromagnetic radiation of the lighting arrangement within an acceptance angle spectrum of the decoupling structure from a first main surface (8) of the light guide structure (1) , wherein an angular spectrum of the electromagnetic radiation (19) radiated in (9) by the lighting arrangement (2) and/or emitted by the light source (3) in the direction of the light guide has a magnitude of at least 15°, preferably at least 20°, more preferably at least 30° and is in particular at least 40° and wherein an angular spectrum (11) of the irradiated electromagnetic radiation (9) and/or the acceptance angle spectrum of the holographic decoupling structure (7) conducted in the light guide (5) from the lighting arrangement (2) to the holographic decoupling structure (7) has a maximum amount is 5° . Light guide structure (1) according to one or more of the preceding claims, wherein the holographic decoupling structure (7) is set up to have a reconstruction angle (20) which essentially coincides with a maximum of the angular spectrum of the light (9) radiated in by the lighting arrangement and/or of the in the light guide from the lighting arrangement to the holographic decoupling structure, the angle spectrum (11) of the radiated electromagnetic radiation (9) corresponds. Light guide structure (1) according to one or more of the preceding claims, wherein more than one holographic decoupling structure (7) is included, in particular up to five holographic decoupling structures (7) are included, each holographic decoupling structure (7) having a different acceptance angle spectrum and/or a different reconstruction angle (20) within the angle spectrum of the electromagnetic radiation (19) radiated in (9) by the illumination arrangement and/or emitted by the light source in the direction of the light guide. Light guide structure (1) according to one or more of the preceding claims, wherein the light guide (1) has a maximum thickness of 5 mm, preferably 3 mm, perpendicular to the planar extent. Light guide structure (1) according to one or more of the preceding claims, wherein the light source (3) is selected from the group comprising lasers and/or LEDs, preferably comprising more than one light source (3), wherein the multiple light sources (3) are in particular arranged next to one another along the first side surface (6). Light guide structure (1) according to one or more of the preceding claims, wherein the lighting arrangement (2) comprises at least one beam-shaping element (13) arranged between the light source (3) and the first side surface (6), which is selected from the group consisting of a lens, diffuser and prism , holographic structure and/or grating. Light guide structure (1) according to one or more of the preceding Claims 1 - 6 , wherein the lighting arrangement (2) does not include an additional beam-shaping element (13) and wherein the light source (3) is arranged directly on the first side surface (6) of the light guide, the light guide (5) and lighting arrangement (2) preferably together in a monolithic Component present, wherein the lighting arrangement (2) is connected in particular by an injection molding process directly to the first side surface (6) of the light guide. Light guide structure (1) according to one or more of the preceding claims, wherein the first side surface (6) has a smooth surface, which has preferably been obtained by a polishing process, more preferably P3 polishing, and which in particular has a square roughness R _q of less than has 2nm. Light guide structure (1) according to one or more of the preceding claims, wherein the at least one holographic decoupling structure (7) is set up for a holographic representation by generating a real (17) and/or virtual image inside and/or outside the light guide structure and in particular inside the first major surface of the light guide structure. Light guide structure (1) according to one or more of the preceding claims, wherein a plurality of holographic decoupling structures (7) are included, each holographic decoupling structure (7) being set up to generate the same image. Light guide structure (1) according to one or more of the preceding claims, comprising a detection arrangement (41), which is arranged on a side surface of the light guide structure (1) and is set up for detecting electromagnetic radiation with a second spectrum from the light guide structure (1), wherein the light guide structure (1) is set up for conducting electromagnetic radiation of the second spectrum, wherein the light guide structure (1) comprises at least one holographic coupling structure (25) which is set up for coupling from onto the first main surface (8) and/or a second Main surface (24) of the light guide structure directed electromagnetic radiation of the second spectrum within an acceptance angle spectrum of the coupling structure (25) in a direction of the detection arrangement (41). Light guide structure (1) after the previous one claim 11 , wherein the detection arrangement (41) comprises a detector and comprises at least one arranged between the detector and the second side surface beam-shaping element, which is selected from the group lens, diffuser, prism, holographic structure and / or grating. Light guide structure (1) according to the preceding claim 11 , wherein the detection arrangement (41) comprises a detector and no additional beam-shaping element and wherein the detector is arranged directly on the second side surface of the light guide (5), with preferably light guide (5), detection arrangement (41) and/or lighting arrangement (2) are present together in a monolithic component, the detection arrangement (41) being connected directly to the side surface of the light guide (5), in particular by an injection molding process. Manufacturing method for a light guide structure (1), preferably according to one or more of the preceding Claims 1 - 13 , comprising the following steps: - providing a flat light guide (5) which is set up for conducting electromagnetic radiation of a first spectrum - providing a lighting arrangement (2) for radiating electromagnetic radiation with a first spectrum into the light guide, comprising at least one light source (3) for emitting electromagnetic radiation with the first spectrum, and connecting the lighting arrangement (2) to a first side surface (6) of the light guide, the angular spectrum of the light source (9) radiated in by the lighting arrangement and/or from the light source in the direction of the The amount of electromagnetic radiation (19) emitted by the light guide is at least 15°, preferably at least 20°, more preferably at least 30° and in particular at least 40° - arranging at least one holographic decoupling structure (7) on and/or in the light guide (5), the decoupling structure (7) is established for decoupling electromagnetic radiation of the lighting arrangement (2) conducted in the light guide structure to the decoupling structure within an acceptance angle spectrum of the decoupling structure (7) from a first main surface (8) of the light guide structure, the light in the light guide (5) from a first side surface (6) to holographic decoupling structure (7) guided angular spectrum (11) of the irradiated electromagnetic radiation (9) and / or the acceptance angle spectrum of the holographic decoupling structure (7) amounts to a maximum of 5 °. Production method according to the preceding claim, additionally comprising the following step: - Connecting the lighting arrangement (2), in particular the light source (3), with a first side surface (6) of the light guide by an injection molding process. Manufacturing method according to one or more of the preceding claims, wherein more than one holographic decoupling structure (7) is included, in particular up to five holographic decoupling structures (7) are included, each holographic decoupling structure (7) having a different acceptance angle spectrum and/or a different reconstruction angle (20) within the angle spectrum of the electromagnetic radiation (19) radiated in (9) by the illumination arrangement and/or emitted by the light source in the direction of the light guide. Operating element comprising a light guide structure (1) according to one or more of the preceding Claims 1 - 14 , comprising a detection arrangement (41), wherein the first and the second spectrum are different, wherein the decoupling structure (7) is set up to generate a holographic representation of a three-dimensional operating area for the operating element and wherein the operating area for the operating element is at least partially outside the light guide structure (1 ) lies.

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