Lighting device

Abstract

A lighting device has a light source assembly of semiconductor light sources arranged laterally next to one another and a reflector assembly of retroreflectors arranged laterally next to one another. The light source assembly and the reflector assembly form a common lighting region of the lighting device in which an emission of light by means of the light source assembly and a light reflection by means of the reflector assembly can be produced. The semiconductor light sources are not covered by the retroreflectors.

Description

[0001] LIGHTING DEVICE

[0002] DESCRIPTION

[0003] The present invention relates to a lighting device.

[0004] This patent application claims the priority of German patent application 10 2023 118 572 . 1 , the disclosure of which is hereby incorporated by reference

[0005] A lighting device can have one or more radiation areas in which light can be emitted. The light can be emitted using semiconductor light sources, such as LEDs. Such a lighting device can be used, for example, in the rear light of a motor vehicle. A retroreflective area can be formed near a radiation area and spatially separated from it, or can be prescribed by law. This allows good visibility to be achieved by illumination with external light radiation when the lighting device is switched off.

[0006] The object of the present invention is to provide an improved lighting device.

[0007] This object is achieved by a lighting device having the features of claim 1. Further advantageous embodiments of the invention are specified in the dependent claims.

[0008] According to one aspect of the invention, a lighting device is proposed. The lighting device has a light source arrangement comprising semiconductor light sources arranged laterally next to one another and a reflector arrangement comprising retroreflectors arranged laterally next to one another. The light source arrangement and the reflector arrangement form a common luminous region of the lighting device, in which light can be emitted by the light source arrangement and reflected by the reflector arrangement. In this case, the semiconductor light sources are not covered by the retroreflectors.

[0009] The proposed lighting device takes the approach of combining a light-emitting region and a retroreflective region instead of providing a spatial separation for these regions. The lighting device has a light source arrangement made up of semiconductor light sources arranged laterally next to one another and a reflector arrangement made up of retroreflectors arranged laterally next to one another. The lighting device is designed such that the two arrangements are combined or merged with one another and thereby together form a common, or in other words, integrated lighting region. In this way, both self-luminosity and retroreflective light can occur in the lighting region of the lighting device.Active luminescence can be caused by the emission of light radiation from semiconductor light sources of the light source arrangement, as well as passive luminescence by the retroreflection of external light radiation from retroreflectors of the reflector arrangement. For this purpose, the light source arrangement and the reflector arrangement, or areas in which the light source arrangement and reflector arrangement are present (light emission area, retroreflective area), can overlap one another.

[0010] The proposed design of the lighting device offers the possibility of implementing the lighting device with fewer components and at lower cost than a conventional device with a spatially separated retroreflective region. Furthermore, a more compact and space-saving design for the lighting device is possible. A homogeneous appearance is also possible, i.e., both in self-illuminating or active operation and in a reflective state of the lighting device.

[0011] The lighting device is further implemented in such a way that the semiconductor light sources are not covered by the retroreflectors. Thus, none of the semiconductor light sources is covered by any of the retroreflectors. In this way, any impairment of the self-luminous or active operation achieved with the light source arrangement due to the reflector arrangement can be avoided.

[0012] The lighting device can thus have a self-luminous region that possesses retroreflective properties without negatively affecting the self-luminous properties. Similarly, the lighting device can have a retroreflective region enhanced by self-luminous properties. The lighting device can thus be used, for example, to create a rear light with integrated retroreflective properties or a retroreflective road sign with integrated self-luminous functionality.

[0013] Further possible details and embodiments that may be considered for the lighting device are described below.

[0014] The above-mentioned feature that the semiconductor light sources are not covered by the retroreflectors can be present when viewed in the radiation direction. The radiation direction can be a main radiation direction in which a predominant portion of the light radiation can be emitted by the semiconductor light sources. The main radiation direction can be perpendicular to a plane in which the semiconductor light sources can be arranged.

[0015] The semiconductor light sources of the light source arrangement, via which light radiation can be generated and emitted, can be LEDs (light-emitting diodes). This can promote a cost-effective construction of the lighting device. The semiconductor light sources can also be unpackaged light-emitting semiconductor chips or LED chips. Such semiconductor chips can have a semiconductor layer sequence for radiation generation and, if appropriate, a conversion layer for radiation conversion.

[0016] With the help of the retroreflectors of the reflector arrangement, retroreflection of external light radiation, i.e., light radiation generated externally or coming from external sources, can be induced. A large portion of the incident light radiation can be reflected back in the direction of, or essentially in the direction of, the incident light radiation. The proportion of the reflected light radiation can be larger, or significantly larger, than is the case with diffuse reflection.

[0017] The retroreflectors of the reflector arrangement can be implemented in the form of suitable structures or components. The retroreflectors can have at least one reflective surface. In a configuration with one reflective surface, this can be curved and partially spherical or hemispherical. Alternatively, several or three reflective surfaces oriented perpendicular to one another can be present. The retroreflectors can be implemented in the form of angle reflectors (also referred to as corner reflectors), lens reflectors, or reflectors with a curved reflective surface.

[0018] It is possible for the semiconductor light sources of the light source arrangement and the retroreflectors of the reflector arrangement to be located in a common or substantially common plane. This allows the lighting device to have a low installation height. Alternatively, the semiconductor light sources and retroreflectors can be arranged in mutually offset planes.

[0019] In the lighting device, light radiation generated by the semiconductor light sources and external light radiation can be emitted and reflected from one side or away from the lighting device with respect to one side. The lighting device can have a planar shape with two opposite main sides, i.e., sides with the largest surface area. The aforementioned side can be one of the two main sides of the lighting device.

[0020] In a further embodiment, the retroreflectors of the reflector arrangement are arranged in areas adjacent to and between the semiconductor light sources. This can be the case, as seen in a plan view of the lighting device or its luminous area. Such a configuration can reliably prevent any interference with the luminous operation of the semiconductor light sources.

[0021] In a further embodiment, the semiconductor light sources of the light source arrangement are present in the region of the centers of the retroreflectors. This can also be the case when viewed from above onto the lighting device or its lighting area. This can also prevent any influence on the operation of the semiconductor light sources. Furthermore, a compact design of the lighting device can be favored. In this case, the lighting device can have a small application area. In this embodiment, a small design compared to the retroreflectors can be considered for the semiconductor light sources arranged centrally to the retroreflectors, or in other words, the retroreflectors can be designed with a larger or significantly larger design than the semiconductor light sources in order to enable the most unhindered backreflection behavior possible.

[0022] The lighting device can have a support structure on which the semiconductor light sources of the light source arrangement and the retroreflectors of the reflector arrangement can be arranged, formed or present, and with which the semiconductor light sources and retroreflectors can be held. The semiconductor light sources and retroreflectors can be located on the same side or on attached sides of the support structure, or can be arranged offset from one another. The support structure can have one or more substrates or layers. The substrates or layers can be transparent or partially transparent. The substrates or layers can also be flexible and thus bendable. The semiconductor light sources and retroreflectors can be provided on the same substrate or layer, or on different substrates or layers.

[0023] In a further embodiment, the lighting device has a carrier substrate on which the semiconductor light sources of the light source arrangement are arranged. The carrier substrate can have a transparent or non-transparent substrate material, for example a plastic material. Furthermore, the carrier substrate can be formed with conductor tracks to which the semiconductor light sources can be electrically connected and via which the semiconductor light sources can be electrically controlled to emit light. The semiconductor light sources can be attached to the carrier substrate by soldering or gluing during production and can be arranged on the carrier substrate by processes such as pick-and-place, LIFT (laser induced forward transfer), stamping and electrostatically assisted stamping.

[0024] In a further embodiment, the retroreflectors of the reflector arrangement are also present on the carrier substrate. This enables cost-effective production of the lighting device.

[0025] In a further embodiment, the semiconductor light sources of the light source arrangement and the retroreflectors of the reflector arrangement are located on one side, i.e., on one and the same substrate side of the carrier substrate. This allows the lighting device to be characterized by a compact and space-saving design.

[0026] In a further embodiment, the semiconductor

[0027] The light sources of the light source arrangement and the retroreflectors of the reflector arrangement are located on opposite sides of the carrier substrate. This configuration makes it possible to form the light source arrangement and the reflector arrangement on the carrier substrate without impairing the other arrangement.

[0028] In a further embodiment, the lighting device has a further substrate on which the retroreflectors of the reflector arrangement are present. The further substrate can, depending on the carrier substrate, have a transparent or non-transparent substrate material, such as a plastic material. This configuration also makes it possible to form the light source arrangement and the reflector arrangement without impairing the other arrangement, in this case on the carrier substrate and the further substrate. The carrier substrate and the further substrate can be connected to one another in a suitable manner, for example by gluing, or also lamination or partial fusing.

[0029] In one embodiment of the lighting device with the carrier substrate carrying the light source arrangement and the further substrate carrying the reflector arrangement, the substrates can be placed one above the other. The carrier substrate and the further substrate can be arranged such that the semiconductor light sources are covered by the further substrate, or the retroreflectors are covered by the carrier substrate. Unhindered light emission from the semiconductor light sources and unhindered retroreflection from the retroreflectors can be achieved by using transparent carrier or substrate materials for the respective substrates. Furthermore, the respective substrate covering the semiconductor light sources or retroreflectors can be flexible in order to enable attachment to the respective other substrate.

[0030] In a further embodiment, the retroreflectors of the reflector arrangement are realized with the aid of surface structures. If the retroreflectors are configured on the carrier substrate, the surface structures are formed on the carrier substrate, and if they are configured on the further substrate, they are formed on the further substrate. By using surface structures, the retroreflective properties of the lighting device can be reliably determined. The surface structures can be three-dimensional structures. The surface structures can be produced using processes such as embossing, milling, printing or by carrying out a molding process.

[0031] In a further embodiment, the retroreflectors of the reflector arrangement are realized by means of recesses. The recesses are provided with a metallization. In this way, effective reflection or mirroring, and thus the intended retroreflection, can be reliably achieved. The metallized recesses can form retroreflectors in the form of corner reflectors or concave mirrors. The recesses can be depressions.

[0032] If the retroreflectors, realized in the form of metallized recesses, are formed on the carrier substrate, the metallized recesses can be located on the side of the carrier substrate on which the semiconductor light sources are also arranged on the carrier substrate. Alternatively, the retroreflectors can be provided on the further substrate. In this embodiment, the metallized recesses, by which the retroreflectors are formed, can be present on a side of the further substrate that faces in the same direction in which the light is emitted by the semiconductor light sources.

[0033] With regard to a design of the retroreflectors in the form of metallized cutouts on the carrier substrate, according to a further embodiment, it is provided that the metallization simultaneously forms conductor tracks of the carrier substrate. The metallization is thus present not only in the region of the cutouts, but also at other locations on the carrier substrate in order to form conductor tracks there. In this way, cost-effective production of the lighting device can be enabled. Depending on the reflectivity of the metallization used, it is also conceivable to provide an additional metallic coating in the region of the cutouts and retroreflectors.

[0034] To achieve retroreflection in the lighting device, not only a mirror coating with the aid of metallization can be used. Reflection behavior based on different refractive indices is also possible. In this context, the following designs may be considered.

[0035] In a further embodiment, the retroreflectors of the reflector arrangement are realized with the aid of cutouts in the carrier substrate. Adjacent to the carrier substrate there is a transparent layer which fills the cutouts and has a higher refractive index than the carrier substrate. The layer in question can be made of a plastic material. In this embodiment, the difference in refractive index can cause total internal reflection and thus retroreflection in the region of the cutouts. The cutouts in the carrier substrate and the layer used can form retroreflectors in the form of corner reflectors or reflectors with a curved reflection surface. The cutouts and the layer filling the cutouts can be present on the side of the carrier substrate on which the semiconductor light sources are also arranged on the carrier substrate.The recesses may be indentations. This also applies to the following design.

[0036] In a further embodiment, the retroreflectors of the reflector arrangement are realized with the aid of cutouts in a first layer arranged on the carrier substrate. Adjacent to the first layer there is a transparent second layer which fills the cutouts and has a higher refractive index than the first layer. The second layer can be made of a plastic material. The first layer can be transparent or non-transparent and can also be made of a plastic material. In this embodiment too, total internal reflection and thus retroreflection can be caused in the region of the cutouts due to the difference in refractive index. Retroreflectors in the form of corner reflectors or reflectors with a curved reflection surface can be formed by the cutouts in the first layer and the two layers.The first layer can be present on the side of the carrier substrate on which the semiconductor light sources are also arranged on the carrier substrate. If a design with semiconductor light sources arranged centrally to the retroreflectors is used, the semiconductor light sources can be arranged within the recesses of the first layer.

[0037] In a further embodiment, the carrier substrate has a transparent substrate material or is formed from a transparent substrate material, so that the carrier substrate can be irradiated. The retroreflectors of the reflector arrangement are realized with the help of elevations on the carrier substrate. The elevations are present on one side of the carrier substrate which is opposite to another side of the carrier substrate, on which side the semiconductor light sources are arranged on the carrier substrate. In this embodiment, total internal reflection and thus retroreflection can be brought about in the region of the elevations, likewise due to a difference in refractive index. The difference in refractive index can exist between the carrier substrate and a medium present in the region of the elevations, for example air, or another material depending on the design or application of the lighting device.Due to the elevations of the carrier substrate, retroreflectors can be formed in the form of corner reflectors or reflectors with a curved reflection surface.

[0038] In a further embodiment, the carrier substrate and the further substrate each have a transparent substrate material or both the carrier substrate and the further substrate are each made of a transparent substrate material so that light can pass through both substrates. The two substrates can be made of the same or different substrate materials. The retroreflectors of the reflector arrangement are realized with the aid of elevations on the further substrate. The carrier substrate and the further substrate are arranged such that the semiconductor light sources and the elevations are located on opposite sides of an arrangement or carrier structure formed from the carrier substrate and the further substrate. In this embodiment too, total internal reflection and thus retroreflection can be brought about in the region of the elevations due to a difference in refractive index.The difference in refractive index can exist between the additional substrate and a medium present in the region of the elevations, for example, air, or, depending on the design or application of the lighting device, another material. The elevations of the additional substrate can form retroreflectors in the form of angle reflectors or reflectors with a curved reflection surface.

[0039] With reference to the aforementioned embodiments, there is the alternative possibility of providing metallization in the area of ​​the elevations. In this way, retroreflection can be based on a mirror coating of the elevations.

[0040] In a further embodiment, the retroreflectors of the reflector arrangement are realized in the form of separate components which are applied to the carrier substrate or the further substrate. In this context, separate can mean that the retroreflectors can be produced separately or independently of the respective substrate during production and subsequently mounted on the respective substrate. In this embodiment, the retroreflectors can be arranged on the carrier substrate or the further substrate using the same assembly techniques as can be considered for the semiconductor light sources. In this way, process costs can be saved and cost-effective production of the lighting device can be enabled.In this sense, the retroreflectors can be attached to the carrier substrate or the other substrate by soldering or gluing, and arranged on the respective substrate by processes such as pick-and-place, LIFT, stamping, and electrostatically assisted stamping. The retroreflectors used in the form of separate components can be corner reflectors, such as triple mirrors or triple prisms, as well as lens reflectors or hemispherical reflectors.

[0041] A homogeneous appearance of the lighting device for an observer can be achieved or promoted with the following additional features. The semiconductor light sources of the light source arrangement can have lateral dimensions of less than one millimeter or in the micrometer range. For example, dimensions in the range of one hundred micrometers or smaller dimensions are possible. The semiconductor light sources used can be micro-LEDs, for example. Furthermore, a distance in the single-digit millimeter range or a smaller distance can be provided for the semiconductor light sources or for each two adjacent semiconductor light sources. The distance can, for example, be less than two millimeters and, for example, be in the range of half a millimeter. The same or comparable specifications with regard to lateral dimensions and distances can be considered for the retroreflectors of the reflector arrangement.

[0042] The semiconductor light sources of the light source arrangement can be arranged in a regular grid. The same can apply to the retroreflectors of the reflector arrangement. Irregular or differently dense arrangements of semiconductor light sources and / or retroreflectors are also possible. In this way, the combined luminous area of ​​the luminous device can be realized with sub-areas of different brightness or luminous intensity and / or different reflection strength.

[0043] The lighting device can be used in relation to the following products and applications : Self-luminous reflector ; traffic sign lighting ; signal light ; vehicle lighting ; tail light ; advertising board .

[0044] For such or other applications, the lighting device can, for example, be embedded in a transparent material or laminated glass. Furthermore, the lighting device can have a flat or planar shape, or a curved shape. The lighting device or its integrated luminous area can also be designed in different geometric shapes. Possible configurations include, for example, a rectangular or circular luminous area or a luminous area with a different shape, such as the shape of a traffic symbol or logo.

[0045] The advantageous embodiments and further developments of the invention explained above and / or reproduced in the subclaims can - except, for example, in cases of clear dependencies or incompatible alternatives - be used individually or in any desired combination with one another.

[0046] The properties, features and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more easily understandable in connection with the following description of exemplary embodiments, which are explained in more detail in connection with the schematic drawings. There show: Figure 1 is a side view of a lighting device having a light source arrangement made up of semiconductor light sources and a reflector arrangement made up of retroreflectors, the two arrangements together forming an integrated lighting area of ​​the lighting device, and self-luminous operation of the lighting device is indicated;

[0047] Figure 2 is a side view of the lighting device of Figure 1, wherein a reflective state of the lighting device is indicated;

[0048] Figures 3 and 4 show a side view and a top view of a lighting device comprising a carrier substrate for carrying semiconductor light sources and retroreflectors;

[0049] Figures 5 and 6 show a side view and a top view of another lighting device comprising a carrier substrate for carrying semiconductor light sources and retroreflectors;

[0050] Figures 7 and 8 show a side view and a top view of a lighting device comprising a carrier substrate for carrying semiconductor light sources and a further substrate for carrying retroreflectors;

[0051] Figures 9 and 10 show a side view and a top view of a further lighting device comprising a carrier substrate for carrying semiconductor light sources and a further substrate for carrying retroreflectors;

[0052] Figures 11 and 12 show a side view and a top view of a lighting device comprising a carrier substrate for supporting semiconductor light sources, wherein the carrier substrate has retroreflectors in the form of metallized recesses; Figures 13 and 14 show a side view and a top view of another lighting device with a carrier substrate which has retroreflectors in the form of metallized recesses;

[0053] Figures 15 and 16 show a side view and a top view of a further lighting device with a carrier substrate which has retroreflectors in the form of metallized recesses;

[0054] Figures 17 and 18 show side views of lighting devices comprising a carrier substrate for carrying semiconductor light sources and a further substrate, the further substrate having retroreflectors in the form of metallized recesses;

[0055] Figures 19 and 20 show side views of lighting devices in which retroreflectors are formed by recesses in a carrier substrate or a layer arranged on the carrier substrate and a further layer filling the recesses;

[0056] Figure 21 is a side view of a lighting device in which retroreflectors are formed by rear elevations of a carrier substrate;

[0057] Figure 22 is a side view of a lighting device with rear retroreflectors arranged on a carrier substrate;

[0058] Figure 23 is a side view of a lighting device comprising a carrier substrate, in which retroreflectors are formed by rear elevations of the carrier substrate and semiconductor light sources are arranged centrally to the retroreflectors on the carrier substrate;

[0059] Figure 24 is a side view of a lighting device comprising a carrier substrate and a further substrate, in which retroreflectors are formed by rear elevations of the further substrate and semiconductor light sources are arranged centrally to the retroreflectors on the carrier substrate;

[0060] Figure 25 is a side view of a lighting device in which retroreflectors are formed by recesses in a layer arranged on a carrier substrate and a further layer filling the recesses, and semiconductor light sources are arranged within the recesses on the carrier substrate;

[0061] Figure 26 is a side view of a lighting device in which retroreflectors are formed by recesses in a carrier substrate and a layer filling the recesses;

[0062] Figure 27 is a side view of a lighting device in which retroreflectors are formed by rear elevations of a carrier substrate;

[0063] Figure 28 is a side view of a lighting device with rear retroreflectors arranged on a carrier substrate;

[0064] Figure 29 is a side view of a lighting device having a curved shape; and

[0065] Figure 30 is a side view of a lighting device with semiconductor light sources and / or retroreflectors on both sides.

[0066] Embodiments of a lighting device 100 are described on the basis of the schematic figures. The lighting device 100 is based on a combination of a light-emitting surface and a retro-reflective surface by combining or superimposing a light source arrangement 110 and a reflector arrangement 120, so that the lighting device 100 has a homogeneous, integrated lighting region 180. The lighting device 100 can thus, among other things, be realized in a cost-effective manner with compact dimensions and a low layer thickness. It is pointed out that the schematic figures may not be true to scale. Therefore, components and structures shown in the figures may be exaggeratedly large or reduced in size for the sake of clarity.Additionally, it is pointed out that features and details mentioned in relation to one embodiment also apply to other embodiments, and that several embodiments and their features can be combined with one another. Corresponding features can only be described in detail with reference to one embodiment. Among other things, possible manufacturing processes are also discussed below. Manufacturing is not depicted in the figures.

[0067] Figures 1 and 2 show a side view of a lighting device 100 in different operating states. The lighting device 100 has a light source arrangement 110 made up of semiconductor light sources 111 arranged laterally next to one another, and a reflector arrangement 120 made up of retroreflectors 121 arranged laterally next to one another. The two arrangements 110, 120 are combined with one another and overlap one another, so that the two arrangements 110, 120 form a common lighting area 180 of the lighting device 100. In the combined lighting area 180, both active lighting and / or Self-illumination by emitting a light radiation 200 from semiconductor light sources 111 of the light source arrangement 110, as indicated in Figure 1, as well as passive illumination by retroreflection of an external light radiation 201 at retroreflectors 121 of the reflector arrangement 120, as indicated in Figure 2.

[0068] The lighting device 100 is further configured such that the semiconductor light sources 111 are not covered by the retroreflectors 121. This feature is present in a plan view of the lighting device 100 or its luminous area 180, or in other words, in a radiation direction relative to the semiconductor light sources 111. In this way, any impairment of the self-luminous operation of the lighting device 100 due to the reflector arrangement 120 can be avoided.

[0069] The lighting device 100 has a flat shape with two opposite main sides, i.e. sides with the largest surface area. The light radiation 200 generated by the semiconductor light sources 111 and the light radiation 201 coming from outside are emitted and reflected from or away from the lighting device 100 with respect to one of the two main sides. In Figures 1 and 2, as well as side views of other figures, this is the upward-facing side. The side in question can be referred to as the front side, or also the emission and reflection side of the lighting device 100. Due to the flat shape of the lighting device 100, the integrated lighting region 180 can also be referred to as the lighting surface.

[0070] As is indicated in Figures 1 and 2, the semiconductor light sources 111 and retroreflectors 121 can be arranged distributed in a common or substantially in a common plane. Alternatively, the semiconductor light sources 111 and retroreflectors 121 can be arranged distributed in planes offset from one another. Furthermore, the semiconductor light sources 111 and retroreflectors 121 can be arranged laterally or alternately laterally next to one another, as seen in a plan view of the lighting device 100 or its front side. This is also indicated in Figures 1 and 2. Alternatively, the semiconductor light sources 111 can be arranged centrally to the retroreflectors 121, as seen in a plan view of the lighting device 100 or its front side. Possible embodiments are explained with reference to the following figures.

[0071] Figure 1 shows the lighting device 100 in an active, self-luminous operation, in which light radiation 200 generated by the semiconductor light sources 110 is emitted by the lighting device 100. This occurs through appropriate electrical control of the semiconductor light sources 110. The light radiation 200 can be white or a different colored light radiation. It is also possible for the light radiation 200 generated by individual, several, or several groups of semiconductor light sources 110 to differ in color. In this sense, the light radiation 200 can comprise different light or partial radiations. The light radiation 200 can, as indicated in Figure 1, be emitted in different directions away from the lighting device 100 or from its front.

[0072] It is possible for a predominant portion of the light radiation 200 to be emitted by the lighting device 100 in a main emission direction. The main emission direction may be perpendicular to a plane in which the semiconductor light sources 111 are arranged. In Figure 1, the middle of the three dashed arrows shown may correspond to the main emission direction. The above-described feature that the semiconductor light sources 111 are not obscured by the retroreflectors 121 may be present with respect to the main emission direction.

[0073] Figure 2 shows the lighting device 100 in a passive reflective state, in which an externally generated light radiation 201 is reflected by the retroreflectors 121 of the lighting device 100 and thereby undergoes retroreflection at the lighting device 100. In this case, a large or predominant part of the incident light radiation 201 can be reflected back by the lighting device 100 in the direction or substantially in the direction of the incident light radiation 201. This situation is indicated in Figure 2 by the dashed arrows for the light radiation 201. In contrast to the idealized representation in Figure 2, the light radiation 201 can be reflected back in the direction of the incident light radiation 201 within a predetermined angular range.

[0074] The lighting device 100 can have a significantly larger number of semiconductor light sources 111 and retroreflectors 121 than is shown in Figures 1 and 2. In this sense, Figures 1 and 2 can be viewed as partial views of the lighting device 100. The same applies to the following figures.

[0075] 1 and 2, be implemented in the form of a single substrate or a single layer. A multi-part or multi-layer design with a plurality of substrates or layers is also possible. In this case, the light source arrangement 110 and reflector arrangement 120 can be arranged on one side of the carrier structure 140 and thus in one plane or be present substantially in one plane, as indicated in Figures 1 and 2, or on opposite sides of the support structure 140 and / or in offset planes.Depending on the application, the support structure 140 can be at least partially transparent and / or flexible. Possible configurations are explained with reference to the following figures.

[0076] The semiconductor light sources 111 of the lighting device 100 can be LEDs (light-emitting diodes). Furthermore, the semiconductor light sources 111 can be unhoused light-emitting semiconductor chips or LED chips. In this case, the semiconductor chips can have a semiconductor layer sequence for generating radiation and optionally a conversion layer for radiation conversion (not shown). Possible or further possible embodiments that can be considered for a lighting device 100 described here are explained with reference to the following figures. The lighting device 100 of Figures 1 and 2 can be understood in this context as a basic concept on which the embodiments described below can be based.In these embodiments, the corresponding lighting device 100 also comprises a light source arrangement 110 composed of semiconductor light sources 111 and a reflector arrangement 120 composed of retroreflectors 121, which together form an integrated luminous region 180 of the lighting device 100. The figures illustrate, among other things, possible designs of the support structure 140 and the retroreflectors 121.

[0077] Figures 3 and 4 show a side view and a top view of a lighting device 100 which has a carrier substrate 141 as a carrier structure. The carrier substrate 141 can be made of a transparent or non-transparent substrate material, for example a plastic material. Semiconductor light sources 111 and retroreflectors 121 of the lighting device 100 are arranged on one side of the carrier substrate 141 on the carrier substrate 141 and are therefore located in a common plane or substantially in a common plane. On the relevant side, the carrier substrate 141 has a contact metallization in the form of conductor tracks 145 for electrically supplying the semiconductor light sources 111, to which conductor tracks 145 the semiconductor light sources 111 are electrically connected. For this purpose, the semiconductor light sources 111 can be arranged on a side facing the carrier substrate 141 orThe back side can have contact elements which can be connected to the conductor tracks 145 or contact surfaces of the conductor tracks 145 via an electrically conductive connecting means, for example a solder or an electrically conductive adhesive (not shown). The conductor tracks 145 can be interrupted in the region of the semiconductor light sources 111, so that the contact elements of the semiconductor light sources 111 can each be connected at these points to one of two spaced-apart conductor tracks 145 (cf. Figure 15 with regard to the interrupted configuration of conductor tracks 145). The retroreflectors 121 can be attached to the carrier substrate 141 via an adhesive, or likewise a solder (not shown).

[0078] In the side view of Figure 3, an arrow indicates a vertically upward direction 210 in which a light radiation 200 generated by the semiconductor light sources 111 can be emitted and an external light radiation 201 can be retroreflected by the lighting device 100 (not shown). The light radiation can also take place in other directions oblique to the direction 210 (cf. Figure 1). The same applies to the retroreflection, which depends on the incident light radiation 201 or its angle of incidence (cf. Figure 2). In this sense, the direction 210 can indicate a half-space in which the respective light radiation 200, 201 can be emitted and reflected by the lighting device 100. The direction 210 can furthermore correspond to the main radiation direction of the lighting device 100.In side views of the following figures, the direction 210 is also shown.

[0079] The retroreflectors of the lighting device 100 shown in Figures 3 and 4 are separately produced components which can be applied to the carrier substrate 141 during the manufacture of the lighting device 100 and fastened there by gluing or soldering. Furthermore, the retroreflectors 121 are designed in the form of corner reflectors 130, as indicated by the triangular shape. The corner reflectors 130, also referred to as corner reflectors, have three reflection surfaces oriented perpendicular to one another. The corner reflectors 130 can be triple mirrors or triple prisms. When designed as a triple mirror, the corner reflectors 130 can have a pyramid-shaped hollow body open on one side (upwardly facing side in Figure 3) and having three inner sides which can serve as reflection surfaces. The inner sides can be metallic or mirrored.When configured as triple prisms, the corner reflectors 130 can have a transparent pyramid-shaped body with four outer sides. Apart from one side (the upward-facing side in Figure 3), three outer sides can serve as reflection surfaces. The outer sides in question can be metallic or mirrored (neither shown).

[0080] As shown in Figure 4, in the lighting device 100 of Figures 3 and 4, as seen in a plan view of the lighting device 100 or its front side, there is an alternating lateral arrangement of the semiconductor light sources 111 and retroreflectors 121, so that the retroreflectors 121 are present in regions next to and between the semiconductor light sources 111. The semiconductor light sources 111 of the light source arrangement 110 and retroreflectors 121 of the reflector arrangement 120 are further arranged in a regular grid.

[0081] Furthermore, lateral dimensions 190 of the semiconductor light sources 111 and distances 191 between them are indicated in Figure 4 using dashed lines and double arrows. The lateral dimensions 190 can be less than one millimeter and in the micrometer range. For example, dimensions 190 in the range of one hundred micrometers or less are possible. The semiconductor light sources 111 in this context can be, for example, micro-LEDs. The distances 191 can be in the single-digit millimeter range or less. Distances 191 of less than two millimeters are conceivable, for example in the range of half a millimeter. The same or similar information with regard to lateral dimensions and distances can be applied to the retroreflectors 121.

[0082] Figures 5 and 6 show a side view and a top view of a further lighting device 100. The lighting device 100 has a carrier substrate 141 with conductor tracks 145, on one side of which semiconductor light sources 111 and retroreflectors 121 are arranged. The retroreflectors 121 are again separately produced components that are applied to the carrier substrate 141 during production. These components are located in areas next to and between the semiconductor light sources 111 and can be fastened to the carrier substrate 141 by means of an adhesive or solder (not shown). In contrast to the lighting device 100 in Figures 3 and 4, the retroreflectors 121 of the lighting device 100 in Figures 5 and 6 are designed in the form of lens reflectors 131, as indicated by the circular shape. The lens reflectors 131 may have a transparent spherical body.A curved partial surface of such a spherical body facing the carrier substrate 141, which can serve as a reflection surface, can optionally be metallic or mirrored (not shown).

[0083] It is possible to provide an irregular arrangement or an arrangement with different densities for retroreflectors 121 instead of an arrangement in a regular grid. This makes it possible to realize sub-regions with different reflection intensities in the illuminated region 180. Such a configuration is shown in Figure 6 for the purpose of illustration in relation to the lighting device 100 of Figures 5 and 6. In this case, there is a larger number of retroreflectors 121 in a region between the four semiconductor light sources 111 shown than in a region outside thereof, which are accordingly arranged at a smaller distance from one another. Such configurations can also be used in relation to lighting devices 100 shown in other figures (for example the lighting device of Figures 3 and 4).In a corresponding manner, the lighting device 100 of Figures 5 and 6 can be realized with retroreflectors 121 arranged in a regular grid. Figures 7 and 8 show a side view and a top view of another, multi-layered lighting device 100. The lighting device 100 has a carrier substrate 141 with conductor tracks 145, on one side of which semiconductor light sources 111 are arranged. The lighting device 100 further has a further substrate 142 placed on the carrier substrate 141, on one side of which retroreflectors 121 are arranged. The retroreflectors 121 are components that are produced separately and applied to the substrate 142, which in the present case are designed in the form of corner reflectors 130 and can be attached to the substrate 142 by means of an adhesive or solder (not shown).

[0084] The further substrate 142 is made of a transparent, flexible substrate material, for example a plastic material. The substrate 142 can be a transparent plastic film. The substrate 142 is arranged on the carrier substrate 141 with a side which is opposite the side equipped with the retroreflectors 121. The substrate 142 is mounted on the side of the carrier substrate 141 on which the semiconductor light sources 111 are also located, so that the semiconductor light sources 111 are covered by the further substrate 142. The retroreflectors 121 are located, as seen in a plan view of the lighting device 100, in regions next to and between the semiconductor light sources 111. The semiconductor light sources 111 and retroreflectors 121 are arranged essentially in a common plane.

[0085] In the lighting device of Figures 7 and 8, the substrate 142 is connected to the carrier substrate 141 in areas next to and between the semiconductor light sources 111. During production, the substrate 142 provided with the retroreflectors 121 can be mounted by adhesive bonding onto the carrier substrate 141 provided with the semiconductor light sources 111. Lamination is also possible, so that the two substrates 141, 142 can be partially fused together at locations next to and between the semiconductor light sources 111 (not shown in each case). The transparent design of the substrate 142 allows light to pass through it, so that light radiation 200 generated by the semiconductor light sources 111 can be emitted unhindered by the lighting device 100.

[0086] Figures 9 and 10 show a side view and a top view of a further lighting device 100, which is constructed similarly to the lighting device 100 of Figures 7 and 8. The lighting device 100 of Figures 9 and 10 comprises a carrier substrate 141 with conductor tracks 145, on one side of which semiconductor light sources 111 are arranged, and a further substrate 142, on one side of which retroreflectors 121 are arranged. The retroreflectors 121 are components that are separately produced and applied to the substrate 142, which in the present case are designed in the form of lens reflectors 131 and are fastened to the substrate 142, for example by means of an adhesive or solder (not shown).

[0087] 9 and 10, the carrier substrate 141 is made of a transparent, flexible substrate material, for example a plastic material, and is implemented, for example, in the form of a flexible plastic film. The further substrate 142 can be transparent or non-transparent and can also be made of a plastic material. The carrier substrate 141 is arranged on the further substrate 142 with a side which is opposite the side equipped with the semiconductor light sources 111. The carrier substrate 141 is mounted on the side of the substrate 142 on which the retroreflectors 121 are also located, so that the retroreflectors 121 are covered by the carrier substrate 141. The retroreflectors 121 are located, as seen in plan view of the lighting device 100, in areas next to and between the semiconductor light sources 111.The semiconductor light sources 111 and retroreflectors 121 are arranged essentially in a common plane.

[0088] With regard to the attachment of the carrier substrate 141, the carrier substrate 141 is connected to the further substrate 142 in areas next to and between the retroreflectors 121. During production, the carrier substrate 141 provided with the semiconductor light sources 111 can be mounted by adhesive bonding onto the substrate 142 provided with the retroreflectors 121. Lamination is also possible, so that the two substrates 141, 142 can be partially fused together at locations next to and between the retroreflectors 121 (not shown in each case). The transparent design of the carrier substrate 141 enables light to pass through it, and thus unhindered retroreflection of external light radiation 201 at the retroreflectors 121.

[0089] It is possible to realize the lighting device 100 of Figures 7 and 8 with retroreflectors 121 in the form of lens reflectors 131. Similarly, for the lighting device 100 of Figures 9 and 10, a design with retroreflectors 121 in the form of angle reflectors 130 can be considered (not shown in each case).

[0090] During the production of the lighting devices 100 explained with reference to Figures 3 to 10, the semiconductor light sources 111 can be arranged on the carrier substrate 141 by processes such as pick-and-place, LIFT (laser induced forward transfer), stamping and electrostatically assisted stamping. The retroreflectors 121, which are implemented in the form of separate components, can be mounted on the carrier substrate 141 or the further substrate 142 using the same processes as mentioned above. Alternatively, retroreflectors 121 can be implemented by surface structuring, which can be present on the carrier substrate 141 or further substrate 142, as described below. Figures 11 and 12 show a side view and a top view of a further lighting device 100.The lighting device 100 has a carrier substrate 141, on one side of which semiconductor light sources 111 are arranged and electrically connected to conductor tracks 145 of the carrier substrate 141. The lighting device 100 also has retroreflectors 121 on this side of the carrier substrate 141, which, as seen in a plan view of the lighting device 100 or its front side, are present in regions next to and between the semiconductor light sources 111. The retroreflectors 121 are realized with the aid of metallized cutouts 150 in the carrier substrate 141. The carrier substrate 141 is accordingly formed with cutouts 150, in the region of which a metallization 147 is applied to the carrier substrate 141. The cutouts 150 are in the form of depressions. The retroreflectors 121 in the form of the metallized recesses 150 and the semiconductor light sources 111 are arranged in mutually offset planes.

[0091] According to the aforementioned embodiments, the carrier substrate 141, apart from the metallization 147 in the region of the cutouts 150 and the conductor tracks 145, can be formed from a transparent or non-transparent plastic material. During production, the cutouts 150 can be created in the carrier substrate 141 by processes such as embossing or milling and subsequently metallized by a coating process. It is also possible to provide the carrier substrate 141 together with the cutouts 150 by carrying out a molding process. In the present case, the cutouts 150 are pyramid-shaped with three inner sides oriented perpendicular to one another, so that the retroreflectors 121 are in the form of corner reflectors, as indicated by the triangular shape.

[0092] Figures 13 and 14 show a side view and a top view of a further lighting device 100 which is constructed in a similar way to the lighting device 100 in Figures 11 and 12. The lighting device 100 in Figures 13 and 14 comprises a carrier substrate 141 which is equipped with semiconductor light sources 111 and which has retroreflectors 121 in areas next to and between the semiconductor light sources 111. The retroreflectors 121 are realized with the aid of metallized cutouts 151 in the carrier substrate 141, i.e. cutouts provided with a metallization 147. The cutouts 151 are in the form of depressions. In contrast to the pyramid-shaped cutouts 150, the cutouts 151 are part-spherical or. hemispherically shaped with the result that the metallized recesses 151 form retroreflectors 121 in the form of concave mirrors, as indicated by the (partial) circular shape in Figures 13 and 14.Manufacturing can be carried out as described above and, for example, can include creating the recesses 151 in the carrier substrate 141 by processes such as embossing or milling and subsequent metallic coating.

[0093] Figures 15 and 16 show a side view and a top view of a lighting device 100 with a further variant of retroreflectors 121 in the form of metallized cutouts 150 of a carrier substrate 141. Here too, the retroreflectors 121, seen in a top view of the lighting device 100, are present in regions next to and between semiconductor light sources 111 of the lighting device 100. Due to the pyramid-shaped cutouts 150, the retroreflectors 121 are present as corner reflectors. In the lighting device 100 of Figures 15 and 16, the metallization 147 is present not only in the region of the cutouts 150 in order to provide the retroreflectors 121, but also at other locations, so that conductor tracks 145 of the carrier substrate 141 are formed by the metallization 147 at the same time.Depending on the reflectivity of the metallization 147, it may be possible to form an additional metallic coating in the area of ​​the recesses 150 and thus retroreflectors 121 in order to enable sufficiently strong reflectivity at these locations (not shown). The design shown in Figures 15 and 16 can be implemented in a corresponding manner with partially or hemispherically shaped recesses 151, and thus retroreflectors 121 in the form of concave mirrors (not shown).

[0094] Figure 17 shows a side view of a further, multi-layered lighting device 100. The lighting device 100 has a carrier substrate 141 with conductor tracks 145, on one side of which semiconductor light sources 111 are arranged. The lighting device 100 further has a further substrate 142 with retroreflectors 121 formed on one side in the form of metallized cutouts 150, of which only one is shown in Figure 17. Production can take place as described above and can, for example, comprise producing the cutouts 150 in the substrate 142 by processes such as embossing or milling and subsequent metallic coating. Pyramid-shaped cutouts 150 are used, so that the retroreflectors 121 are present as corner reflectors.

[0095] The carrier substrate 141 is made of a transparent substrate material, for example a plastic material. The further substrate 142 is made of a transparent or non-transparent substrate material, which can also be a plastic material. The two substrates 141, 142 are placed one above the other, so that the substrate 142, with a side having the retroreflectors 121, faces a side of the carrier substrate 141 which is opposite the side equipped with the semiconductor light sources 111. The arrangement of the two substrates 141, 142 is such that the retroreflectors 121, seen in a plan view of the lighting device 100, are located in regions next to and between the semiconductor light sources 111. In this case, an appearance as shown in Figure 12 can be present, for example.The transparent design of the carrier substrate 141 enables it to be illuminated and thus retroreflects external light radiation 201 at the retroreflectors 121 (not shown). In the lighting device 100 of Figure 17, the semiconductor light sources 111 and retroreflectors 121 present on the various substrates 141, 142 are located in planes offset from one another. The carrier substrate 141 can be mounted on the further substrate 142 so that the two substrates 141, 142 can be adjacent to one another, contrary to the schematic representation in Figure 17. During production, the carrier substrate 141 equipped with the semiconductor light sources 111 can be attached to the substrate 142 formed with the retroreflectors 121 by adhesive bonding.Lamination is also possible, so that the two substrates 141, 142 can be partially fused together at locations next to and between the retroreflectors 121 (not shown in each case).

[0096] A possible modification of the lighting device 100 of Figure 17 consists in providing an inverted superimposed arrangement for the substrates 141, 142. For illustration, Figure 18 shows a side view of a further lighting device 100 implemented in this sense. Here, the substrates 141, 142 are placed one above the other in such a way that the carrier substrate 141, with a side equipped with semiconductor light sources 111, faces a side of the substrate 142 which is opposite a side provided with retroreflectors 121 in the form of metallized recesses 150. In this embodiment, the substrate 142 is formed from a transparent substrate material, for example a plastic material. This allows it to be irradiated through, so that light radiation 200 generated by the semiconductor light sources 111 can be emitted through the substrate 142 by the lighting device 100 (not shown).The carrier substrate 141 can be formed from a transparent or non-transparent substrate material, which can also be a plastic material. The substrate 142 can be attached to the carrier substrate 141 in a suitable manner, for example by means of an adhesive (not shown). In the lighting device 100 shown in Figure 18, corresponding to embodiments in other figures, the semiconductor light sources 111 are not covered by the retroreflectors 121. This feature is present as seen in the emission or main emission direction (corresponds to direction 210). In the lighting device of Figure 18, this is realized in that the retroreflectors 121, as seen in a plan view of the lighting device 100, are located in regions next to and between the semiconductor light sources 111. In this case, an appearance corresponding to Figure 12 can be present, for example.

[0097] The lighting devices 100 shown in Figures 17 and 18 can be realized in a corresponding manner with partially or hemispherically shaped recesses 151, and thus retroreflectors 121 in the form of concave mirrors (not shown).

[0098] Figure 19 shows a side view of a lighting device 100 with a further variant of a surface structuring for providing retroreflectors 121. The lighting device 100 has a carrier substrate 141, on one side of which semiconductor light sources 111 are arranged and electrically connected to conductor tracks 145 of the carrier substrate 141. Furthermore, retroreflectors 121 are formed on the carrier substrate 141 and, as seen in a plan view of the lighting device 100, are present in regions next to and between the semiconductor light sources 111. Only one retroreflector 121 is shown in Figure 19. Viewed in plan view, the appearance may correspond to Figure 12. This may also apply to lighting devices 100 in subsequent figures.

[0099] In the lighting device 100 of Figure 19, the retroreflectors 121 and semiconductor light sources 111 are further arranged in mutually offset planes. The retroreflectors 121 are realized by means of recesses 150 in the carrier substrate 141 and a transparent layer 170 applied to the carrier substrate 141 and filling the recesses 150. The recesses 150 and the transparent layer 170 are located on the side of the carrier substrate 141 on which the semiconductor light sources 111 are also arranged on the carrier substrate 141. The transparent layer 170 adjoins not only the carrier substrate 141 but also the semiconductor light sources 111 and can, as shown in Figure 19, be flush with the front sides of the semiconductor light sources 111.

[0100] The transparent layer 170 can be formed from a plastic material. The transparent layer 170 or a layer material of the layer 170 has a higher refractive index than the carrier substrate 141 or a substrate material thereof. The substrate material of the carrier substrate 141 can be transparent or non-transparent and can also be a plastic material. Due to the difference in refractive index, light reflection (total internal reflection) and thus retroreflection of an external light radiation 201 can be caused by the carrier substrate 141 in the region of the cutouts 150, as indicated in Figure 19 using a possible beam path of the light radiation 201, so that the cutouts 150 can act as retroreflectors 121 as intended.In this case, the external light radiation 201 can be coupled into the layer 170 via a side of the layer 170 facing away from the carrier substrate 141, reach the carrier substrate 141 and the recesses 150, and after retroreflection has taken place here, be coupled out of the layer 170 again via the aforementioned side of the layer 170.

[0101] The recesses 150 can be created in the carrier substrate 141 during the manufacture of the lighting device 100 of Figure 19 by processes such as embossing or milling. It is also possible to provide the carrier substrate 141 together with the recesses 150 by performing a molding process. The transparent layer 170 can be applied to the carrier substrate 141 by processes such as dispensing, printing, or performing a molding process. In the present case, pyramid-shaped recesses 150 with three inner sides oriented perpendicular to one another are used, so that the retroreflectors 121 are in the form of corner reflectors.

[0102] Figure 20 shows a side view of a lighting device 100 with a further embodiment of a surface structuring for providing retroreflectors 121, which is constructed similarly to the lighting device 100 of Figure 19. The lighting device 100 of Figure 20 has a carrier substrate 141, on one side of which semiconductor light sources 111 are arranged. Furthermore, retroreflectors 121 are formed on the carrier substrate 141, which, as seen in a plan view of the lighting device 100, are located in regions next to and between the semiconductor light sources 111. Only one retroreflector 121 is shown in Figure 20. The retroreflectors 121 are realized with the aid of a layer arrangement comprising two layers 170, 171 and cutouts 150 in the layer 171. The layer arrangement is formed on the side of the carrier substrate 141 on which the semiconductor light sources 111 are also arranged on the carrier substrate 141.

[0103] The layers 170, 171 are referred to below as first layer 171 and second layer 170. At least the second layer 170 is transparent. The first layer 171 can be transparent or non-transparent. The first layer 171 borders the carrier substrate 141 and the semiconductor light sources 111 and, as shown in Figure 20, can be flush with the front sides of the semiconductor light sources 111. The second layer 170 borders at least the first layer 171 and, according to the embodiment of Figure 20, also the semiconductor light sources 111 or their front sides. The second layer 170 applied to the first layer 171 fills the recesses 150 of the first layer 171. In self-luminous operation of the lighting device 100, a light radiation 200 generated by the semiconductor light sources 111 can be emitted by the lighting device 100 through the second layer 170 (not shown).Both layers 170, 171 can be formed from a plastic material. The second layer 170 (or a corresponding layer material of layer 170) has a higher refractive index than the first layer 171 (or a corresponding layer material of layer 171). Due to the difference in refractive index, light reflection (total internal reflection) and thus retroreflection of an external light radiation 201 can be caused by the first layer 171 in the region of the cutouts 150, as indicated in Figure 20 using a possible beam path of the light radiation 201, so that the cutouts 150 can serve as retroreflectors 121 as intended.In this case, the external light radiation 201 can be coupled into the second layer 170 via a side of the second layer 170 facing away from the first layer 171, reach the first layer 171 and the recesses 150, and, after retroreflection has taken place here, be coupled out of the second layer 170 again via the aforementioned side of the second layer 170.

[0104] The layers 170, 171 can be produced during the manufacture of the lighting device 100 of Figure 20 by processes such as dispensing, printing, or performing a molding process on the carrier substrate 141. If the recesses 150 are not formed in one of these processes, embossing or milling can additionally be considered, for example, to provide the recesses 150 in the layer 171. In the present case, pyramid-shaped recesses 150 with three inner sides oriented perpendicular to one another are used, so that the retroreflectors 121 are in the form of corner reflectors.

[0105] Figure 21 shows a side view of a lighting device 100 with a further variant of a surface structuring for providing retroreflectors 121. The lighting device 100 comprises a carrier substrate 141, on one side of which semiconductor light sources 111 are arranged and electrically connected to conductor tracks 145 of the carrier substrate. The carrier substrate 141 is formed with retroreflectors 121 which, as seen in a plan view of the lighting device 100, are present in regions next to and between the semiconductor light sources 111. Only one retroreflector 121 is shown in Figure 21. The retroreflectors 121 and semiconductor light sources 111 are located in planes offset from one another. The carrier substrate 141 is formed from a transparent substrate material, for example a plastic material, so that the carrier substrate 141 can be irradiated.The retroreflectors 121 are realized with the aid of protruding structural elements, i.e., elevations 160 of the carrier substrate 141. The elevations 160 are present on a side of the carrier substrate 141 that is opposite the side of the carrier substrate 141 equipped with the semiconductor light sources 111. The side carrying the semiconductor light sources 111 and the side having the elevations 160 can also be referred to as the front and back sides of the carrier substrate 141. Accordingly, the elevations 160 can be referred to as rear elevations 160.

[0106] In the lighting device 100 of Figure 21, likewise due to a difference in refractive index, a light reflection (total internal reflection) and thus retroreflection of an external light radiation 201 can be brought about on the carrier substrate 141 in the region of the elevations 160, as is indicated in Figure 21 using a possible beam path of the light radiation 201, so that the elevations 160 can serve as retroreflectors 121 as intended. The external light radiation 201 can be coupled into the carrier substrate 141 via the front side, reach the back side of the carrier substrate 141 and the elevations 160, and after a retroreflection taking place here, be coupled out of the carrier substrate 141 again via the front side. The refractive index difference can exist between the carrier substrate 141 and a medium present in the region of the back side and elevations 160 of the carrier substrate 141.Depending on the application or further configuration of the lighting device 100, the medium can be air or another material (not shown). The elevations 160 are pyramid-shaped in the present case with three sides or outer sides oriented perpendicular to one another, so that the retroreflectors 121 are in the form of corner reflectors. During the manufacture of the lighting device 100 of Figure 21, the carrier substrate 141 with the elevations 160 can be provided, for example, by embossing or performing a molding process.

[0107] Figure 22 shows a side view of a further lighting device 100 with a carrier substrate 141 and semiconductor light sources 111 arranged on one side of the carrier substrate 141. The lighting device 100 has retroreflectors 121 which, as seen in a plan view of the lighting device 100, are located in regions next to and between the semiconductor light sources 111. Only one retroreflector 121 is shown in Figure 22. The carrier substrate 141 is formed from a transparent substrate material, for example a plastic material. The retroreflectors 121 are separately produced components which can be applied to the carrier substrate 141 during the production of the lighting device 100 and fastened there by adhesive. The retroreflectors 121 are applied to a side of the carrier substrate 141 which is opposite to the side carrying the semiconductor light sources 111.In this way, the retroreflectors 121 and semiconductor light sources 111 are located in planes offset from one another. The aforementioned sides of the carrier substrate 141 can also be referred to as the front and back, and accordingly the retroreflectors 121 can also be referred to as rear retroreflectors 121. The transparent design of the carrier substrate 141 enables it to be illuminated and thus allows external light radiation 201 to be retroreflected at the retroreflectors 121 (not shown). The retroreflectors 121 are in the form of corner reflectors 130, for example triple prisms, as indicated by the triangular shape. Figure 23 shows a side view of a lighting device 100 with a further variant of a surface structuring, which is constructed in a manner comparable to the lighting device 100 of Figure 21.The lighting device 100 of Figure 23 has a carrier substrate 141 with semiconductor light sources 111 arranged on one side of the carrier substrate 141 and electrically connected to conductor tracks 145 of the carrier substrate 141. The carrier substrate 141 is formed from a transparent substrate material, for example a plastic material, so that the carrier substrate 141 can be irradiated. The carrier substrate 141 is formed with retroreflectors 121, which are realized with the aid of elevations 160 of the carrier substrate 141. The elevations 160 are present on a side of the carrier substrate 141 which is opposite the side of the carrier substrate 141 provided with the semiconductor light sources 111. The retroreflectors 121 and semiconductor light sources 111 are therefore located in planes offset from one another.The side carrying the semiconductor light sources 111 and the side having the projections 160 may also be referred to as front and rear sides, and accordingly the projections 160 and retroreflectors 121 may be referred to as rear projections 160 and rear retroreflectors 121.

[0108] The lighting device 100 of Figure 23 is, in contrast to the lighting device 100 of Figure 21, designed such that the semiconductor light sources 111, seen in a plan view of the lighting device 100, are located in the region of the centers of the elevations 160 and thus retroreflectors 121. In this embodiment, the most unhindered backreflection behavior possible is made possible by the fact that the semiconductor light sources 111 arranged centrally to the retroreflectors 121 have a small design compared to the retroreflectors 121, or in other words, the elevations 160 forming the retroreflectors 121 are realized with (significantly) larger dimensions than the semiconductor light sources 111.In the lighting device 100 of Figure 23, corresponding to the lighting device 100 of Figure 21, an external light radiation 201 can be coupled into the carrier substrate 141 via the front side, reach the rear elevations 160, and, after retroreflection taking place here, be coupled out of the carrier substrate 141 again via the front side (not shown). The light reflection and thus retroreflection is again based on the exploitation of a difference in refractive index between the carrier substrate 141 and a medium present in the region of the elevations 160 (for example air). In the present case, the elevations 160 are pyramid-shaped with three sides oriented perpendicular to one another, so that the retroreflectors 121 are in the form of corner reflectors.The manufacture of the lighting device 100 of Figure 23 may include providing the carrier substrate 141 with the rear elevations 160 by embossing or performing a molding process.

[0109] Figure 24 shows a side view of a further lighting device 100, which has a similar structure to the lighting device 100 of Figure 23 and, in contrast to the latter, has a multi-layer construction. The lighting device 100 of Figure 23 has a carrier substrate 141 with semiconductor light sources 111 arranged on one side of the carrier substrate 141 and electrically connected to conductor tracks 145 of the carrier substrate 141, as well as a further substrate 142. The substrates 141, 142 are each made of a transparent substrate material, for example a plastic material. These can be the same or different substrate materials. The substrate 142 has, similar to the carrier substrate 141 of Figure 23, elevations 160 on one side, by means of which retroreflectors 121 of the lighting device 100 are realized.These are pyramid-shaped elevations 160 with three sides oriented perpendicular to each other, so that retroreflectors 121 are in the form of corner reflectors. During production, the substrate 142 with the elevations 160 can be provided by embossing or performing a molding process.

[0110] In the lighting device 100 of Figure 24, the two substrates 141, 142 are arranged such that the side of the carrier substrate 141 carrying the semiconductor light sources 111 and the side of the substrate 142 formed with the elevations 160 point in opposite directions, and the semiconductor light sources 111 and retroreflectors 121 are located on opposite sides of an arrangement composed of the two substrates 141, 142, and thus in planes offset from one another. The relevant sides can also be referred to as the front and rear sides, and accordingly the retroreflectors 121 can also be referred to as rear-side retroreflectors 121. The substrates 141, 142 are further arranged such that the semiconductor light sources 111, seen in plan view of the lighting device 100, are placed centrally to the elevations 160 and thus retroreflectors 121.Here, too, the elevations 160 are configured with (significantly) larger dimensions than the semiconductor light sources 111 in order to provide the most unhindered backreflection behavior possible. The carrier substrate 141 and further substrates 142 can be connected to one another, for example, by gluing or lamination.

[0111] The transparent design of the substrates 141, 142 enables them to be irradiated through, and thus retroreflected by, external light radiation 201 at the elevations 160, which can thereby act as retroreflectors 121 as intended. Similar to the lighting devices 100 of Figures 21 and 23, the light radiation 201 can be coupled into the substrate 142 after irradiating the carrier substrate 141, reach the elevations 160, radiate in the direction of the carrier substrate 141 after retroreflection takes place there, decoupled from the substrate 142, and radiate from the lighting device 100 after irradiating the carrier substrate 141 again (not shown). With regard to light and retroreflection, a difference in refractive index, in this case between the substrate 142 and a medium present in the region of the elevations 160 (for example air), is also exploited here.

[0112] Figure 25 shows a side view of a further lighting device 100 which has a similar structure to the lighting device 100 of Figure 20. The lighting device 100 of Figure 25 has a carrier substrate 141 on one side of which semiconductor light sources 111 are arranged, and on which retroreflectors 121 are also formed. The retroreflectors 121 are realized with the aid of a layer arrangement comprising a first layer 171 and a second layer 170 and cutouts 150 in the first layer 171. The layer arrangement is formed on the side of the carrier substrate 141 on which the semiconductor light sources 111 are also arranged on the carrier substrate 141. At least the second layer 170 is transparent. The first layer 171 can be transparent or non-transparent. Both layers 170, 171 can be formed from a plastic material.The second layer 170 applied on the first layer 171 fills the recesses 150 of the first layer 171.

[0113] In contrast to the lighting device 100 of Figure 20, the semiconductor light sources 111 in the lighting device 100 of Figure 25 are located within the cutouts 150 of the first layer 171, and here in the region of the centers of the cutouts 150 and thus retroreflectors 121. The semiconductor light sources 111 are embedded in the transparent second layer 170. During self-luminous operation of the lighting device 100, light radiation 200 generated by the semiconductor light sources 111 can be emitted by the lighting device 100 through the second layer 170 (not shown). The cutouts 150 of the first layer 171 in the present case have a truncated pyramid shape with three inner sides oriented perpendicular to one another, so that the retroreflectors 121 have a back-reflection behavior corresponding to corner reflectors.In this embodiment, the most unhindered back-reflection behavior possible is made possible by the fact that the recesses 150 and thus retroreflectors 121 are realized with (significantly) larger dimensions than the semiconductor light sources 111. Due to the arrangement of the semiconductor light sources 111 within the recesses 150 of the first layer 171, the semiconductor light sources 111, similar to lighting devices 100 in other figures, are not obscured by the retroreflectors 121 when viewed in the emission or main emission direction (corresponding to direction 210).

[0114] In the lighting device 100 of Figure 25, the retroreflection is again based on a difference in refractive index. For this purpose, the second layer 170 (or a corresponding layer material of the layer 170) has a higher refractive index than the first layer 171 (or a corresponding layer material of the layer 171). As a result, light reflection (total internal reflection) and thus retroreflection of an external light radiation 201 can be brought about at the first layer 171 in the region of the cutouts 150, as indicated in Figure 20 using a possible beam path of the light radiation 201, so that the cutouts 150 can act as retroreflectors 121 as intended. The layers 170, 171 can be manufactured as described above for Figure 20.

[0115] The lighting devices 100 of Figures 19 to 25, in which the induction of retroreflection is based on surface structuring and the utilization of a difference in refractive index, can be implemented not only with retroreflectors 121 in the form of, or with an effect corresponding to, corner reflectors. Embodiments with retroreflectors 121 with a curved reflection surface are also possible.

[0116] For illustration, Figure 26 shows a side view of a further lighting device 100, which represents a modification of the lighting device 100 of Figure 19. Instead of pyramid-shaped cutouts 150, the carrier substrate 141 of the lighting device 100 of Figure 26 has partially spherical or hemispherical cutouts 151, so that the respective cutouts 151, together with the transparent layer 170 filling the cutouts 151, create retroreflectors 121 with a curved reflection surface. Only one retroreflector 121 is shown in Figure 26.

[0117] A corresponding modification can be considered for the lighting device 100 of Figure 20, in which partially spherical or hemispherical recesses 151 are provided for the first layer 171 instead of the recesses 150. The same applies to the lighting device 100 of Figure 25, in which recesses in the shape of a spherical segment can be provided for the first layer 171 (not shown in each case).

[0118] Figure 27 shows, for illustrative purposes, a side view of a further lighting device 100, which represents a modification of the lighting device 100 of Figure 21. Instead of pyramid-shaped elevations 160, the carrier substrate 141 of the lighting device 100 of Figure 27 has partially spherical or hemispherical elevations 161 on the rear side, which elevations can act as retroreflectors 121 with a curved reflection surface due to a difference in refractive index between the carrier substrate 141 and a medium present in the region of the elevations 160. Only one retroreflector 121 of this is shown in Figure 27.

[0119] For the lighting devices 100 of Figures 23 and 24, corresponding modifications can be used in that the carrier substrate 141 or the further substrate 142 is formed on the back with partially spherical or hemispherical elevations 161 (not shown in each case).

[0120] Figure 28 shows, for illustration purposes, a side view of a further lighting device 100 which is a modification of the lighting device 100 of Figure 22. Instead of retroreflectors 121 in the form of corner reflectors 130, the lighting device 100 of Figure 28 provides retroreflectors 121 in the form of partial spherical or hemispherical reflectors 132 which are applied as separately produced components to the back of the carrier substrate 141 and can be fastened there by adhesive. The partial or hemispherical reflectors 132 can have a transparent body whose curved outer side can be metallic or mirrored (not shown). Only one reflector 132 is shown in Figure 28.

[0121] A lighting device 100 constructed according to the approaches described above can have a homogeneous self-luminous region, which can also have homogeneous retroreflective properties without negatively affecting the self-luminous properties. Similarly, the lighting device 100 can have a retroreflective region that is expanded or supplemented by self-luminous properties.

[0122] The lighting device 100 can therefore be used, for example, in or in the form of a rear light with integrated retroreflective properties, or a retroreflective road sign with integrated self-luminous operation. The lighting device 100 can further be used, for example, to create a self-luminous reflector, a signal light, an advertising board, and the like. For such applications, the lighting device 100 can, for example, be embedded in a transparent material or laminated glass (not shown). The lighting device 100 can also have a flat or planar shape, as shown, for example, in Figures 1 and 2. Alternatively, the lighting device 100 can have a curved shape or be offset into a curved shape, as shown in Figure 29 for example. The curved shape can, for example, correspond to the contour of a rear light.Providing a curved shape can be made possible by a flexible design of a support structure 140 of the lighting device 100. The support structure 140 can also be transparent. The lighting device 100 or its integrated luminous region 180 (cf. Figures 1 and 2) can also be designed in different geometric shapes. For example, a rectangular or circular luminous region 180 is possible. Another example is a luminous region 180 in the form of a traffic symbol or logo (not shown).

[0123] For the lighting device 100, it can also be provided to enable light emission and reflection not only in relation to one side or main side, but on both sides. For illustration, Figure 30 shows a side view of a further lighting device 100. In this case, light emission and retroreflection can be brought about with the aid of a light source arrangement 110 comprising semiconductor light sources 111 and a reflector arrangement 120 comprising retroreflectors 121, which together form an integrated lighting area 180, from or in relation to a main side of the lighting device 100. This is illustrated in Figure 30, corresponding to previous figures, using a direction 210 pointing vertically upwards. The direction 210 can indicate a first half-space in which the light emission and reflection can take place.

[0124] As shown in dashed lines in Figure 30, the lighting device 100 further comprises a further light source arrangement 119 made up of semiconductor light sources 111 and / or a further reflector arrangement 129 made up of retroreflectors 121, with the aid of which light emission and / or retroreflection can be effected with respect to an opposite main side of the lighting device 100. This is illustrated in Figure 30 by means of a vertically downward-pointing direction 219. The direction 219 can indicate a second half-space in which the light emission and / or reflection can take place. If the lighting device 100 has both the further light source arrangement 119 and the further reflector arrangement 129, these can together form a further combined lighting region of the lighting device 100.

[0125] Such a two-sided design can be implemented in different ways. Figure 30 shows an example of an embodiment of the support structure 140 of the lighting device 100 in the form of a single substrate, on which semiconductor light sources 111 and / or retroreflectors 121 can be arranged or present on both sides. Furthermore, Figure 30 shows retroreflectors 121 in the form of separately produced and applied components corresponding to the embodiment of Figure 5 (with the support substrate 141 and the lens reflectors 131). Alternatively, a two-sided design can be implemented in a different way, for example by correspondingly applying approaches and embodiments shown in other figures, or also for example by using two of the lighting devices 100 shown in other figures oriented opposite to one another in the form of a combined lighting device 100 (not shown).

[0126] In addition to the embodiments described above and illustrated in the figures, further embodiments are conceivable which may include further modifications and / or combinations of features.

[0127] In this sense, the above information on materials can be considered as examples, and other materials may be used. The same applies to the above numerical data.

[0128] For the lighting devices 100 shown in Figures 21, 23, 24 and 27, one possible modification consists in providing metallization in the region of the elevations 160, 161. In this way, the retroreflection caused in the region of the elevations 160, 161 can be based on a mirror coating. With reference to the lighting device 100 shown in Figure 21, a further modified embodiment according to Figure 24 can be considered in that it is realized in multiple layers with a carrier substrate 141 and another substrate 142, wherein elevations 160 are provided on the another substrate 142.

[0129] A further embodiment consists in providing, in accordance with Figure 6, an irregular or differently dense arrangement for semiconductor light sources 111 instead of an arrangement in a regular grid. This allows sub-areas with different brightness or luminous intensity to be realized in a luminous area 180.

[0130] Although the invention has been illustrated and described in detail by means of preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

[0131] LIST OF REFERENCE SYMBOLS Lighting device Light source arrangement Semiconductor light source Further light source arrangement Reflector arrangement Retroreflector Further reflector arrangement Angle reflector Lens reflector Hemispherical reflector Carrier structure Carrier substrate Further substrate Conductor track Metallization Recess Recess Elevation Elevation Layer Layer Luminous area Lateral dimension Distance Light radiation Light radiation Direction Direction

Claims

PATENT CLAIMS 1. A lighting device (100) comprising: a light source arrangement (110) comprising semiconductor light sources (111) arranged laterally next to one another; and a reflector arrangement (120) comprising retroreflectors (121) arranged laterally next to one another, wherein the light source arrangement (110) and the reflector arrangement (120) form a common luminous region (180) of the lighting device (100), in which light emission by the light source arrangement (110) and light reflection by the reflector arrangement (120) can be brought about, and wherein the semiconductor light sources (111) are not covered by the retroreflectors (121).

2. Lighting device according to claim 1, wherein the retroreflectors (121) are present in regions next to and between the semiconductor light sources (111).

3. Lighting device according to claim 1, wherein the semiconductor light sources (111) are present in the region of centers of the retroreflectors (121).

4. Lighting device according to one of the preceding claims, comprising a carrier substrate (141) on which the semiconductor light sources (111) are arranged, wherein the carrier substrate (141) has conductor tracks (145) to which the semiconductor light sources (111) are electrically connected.

5. Lighting device according to claim 4, wherein the retroreflectors (121) on the carrier substrate (141) are present.

6. Lighting device according to one of claims 4 or 5, wherein the semiconductor light sources (111) and the retroreflectors (121) are present on one side of the carrier substrate (141).

7. Lighting device according to one of claims 4 or 5, wherein the semiconductor light sources (111) and the retroreflectors (121) are present on opposite sides of the carrier substrate (141).

8. Lighting device according to claim 4, comprising a further substrate (142) on which the retroreflectors (121) are present.

9. Lighting device according to claim 8, wherein the carrier substrate (141) and the further substrate (142) are arranged such that the semiconductor light sources (111) are covered by the further substrate (142) or the retroreflectors (121) are covered by the carrier substrate (141).

10. Lighting device according to one of claims 4 to 9, wherein the retroreflectors (121) are realized by means of surface structures which are formed on the carrier substrate (141) or the further substrate (142).

11. Lighting device according to claim 10, wherein the retroreflectors (121) are realized by means of recesses (150, 151), and wherein the recesses (150, 151) are provided with a metallization (147).

12. Lighting device according to claim 11, wherein conductor tracks (145) of the carrier substrate (141) are formed by the metallization (147).

13. Lighting device according to one of claims 11 or 12, wherein the retroreflectors (121) are formed in the form of the metallized recesses (150, 151) on the carrier substrate (141) and are located on a side of the carrier substrate (141) on which the semiconductor light sources (111) are arranged on the carrier substrate (141).

14. Lighting device according to claim 11, wherein the retroreflectors (121) are formed in the form of the metallized recesses (150, 151) on the further substrate (142) and are located on a side of the further substrate (142) which points in the same direction in which light is emitted from the semiconductor light sources (111).

15. Lighting device according to claim 10, wherein the retroreflectors (121) are realized by means of recesses (150, 151) in the carrier substrate (141), and wherein adjacent to the carrier substrate (141) there is a transparent layer (170) filling the recesses (150, 151) which has a higher refractive index than the carrier substrate (141).

16. Lighting device according to claim 10, wherein the retroreflectors (121) are realized by means of recesses (150) in a first layer (171) arranged on the carrier substrate (141), and wherein adjacent to the first layer (171) there is a transparent second layer (170) filling the recesses (150) and having a higher refractive index than the first layer (171).

17. Lighting device according to claim 10, wherein the carrier substrate (141) comprises a transparent substrate material, wherein the retroreflectors (121) are arranged by means of elevations (160, 161) of the carrier substrate (141) are realized, and wherein the elevations (160, 161) are present on one side of the carrier substrate (141) which is opposite to a further side of the carrier substrate (141) on which the semiconductor light sources (111) are arranged on the carrier substrate (141).

18. Lighting device according to claim 10, wherein the carrier substrate (141) and the further substrate (142) each have a transparent substrate material, wherein the retroreflectors (121) are realized with the aid of elevations (160) of the further substrate (142), and wherein the carrier substrate (141) and the further substrate (142) are arranged such that the semiconductor light sources (111) and the elevations (160) are located on opposite sides of an arrangement formed from the carrier substrate (141) and the further substrate (142).

19. Lighting device according to one of claims 4 to 9, wherein the retroreflectors (121) are realized in the form of separate components which are applied to the carrier substrate (141) or the further substrate (142).

20. Lighting device according to one of the preceding claims, wherein the semiconductor light sources (111) have lateral dimensions in the micrometer range, and / or wherein the semiconductor light sources (111) have a distance in the single-digit millimeter range or a smaller distance, and / or wherein the retroreflectors (121) are designed in the form of one of the following: corner reflectors (130); lens reflectors (131); reflectors with a curved reflection surface.

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