Lighting device and method for its manufacture

Abstract

Method for manufacturing a lighting device (100), comprising the following steps: - Providing an injection mold with at least one first cylindrical cavity for filling with an injection molding material, - Insertion of a transverse transport section (300) in the form of a planar film with a first narrow side (350) into the cylindrical cavity along a longitudinal extension (L) of the first cylindrical cavity; - Filling the at least first cylindrical cavity to create a longitudinal transport section (200) with a lateral surface (M) on which the coupled light is guided in the longitudinal transport section (200) by total internal reflection, and to connect the first narrow side (350) of the planar film with the injection molding material of the longitudinal transport section (200); - Introducing secondary deflection elements (340) on the surface and / or in the volume of the transverse transport section (300) and - Arranging at least one light source, in particular an RGB LED, at at least one coupling surface of the longitudinal transport section (200).

Description

[0001] The invention relates to a lighting device according to the preamble of claim 1 and a method for manufacturing this lighting device.

[0002] For interior lighting, especially in vehicle interiors, LEDs have become the standard in lighting technology. A further development of monochromatic LEDs are RGB LEDs, which, with their three primary colors, offer numerous possibilities for ambient lighting. Efforts to implement RGB LED technology focus not only on optimizing the homogeneity of flat light guides, particularly in door panels or instrument panels, which, together with materials such as perforated leather or textiles, create dynamic lighting scenarios, but also on the energy-efficient use of this technology.

[0003] The invention described here is not applicable to the field of automotive exterior lights, since in this area there are legal requirements regarding luminance homogeneity and parallelized light, and corresponding regulations are associated with this.

[0004] From DE 100 32 927 A1, DE 20 2016 100 986 U1 and DE 10 2019 122 470 A1, a lighting device for illuminating an interior space is known, comprising a light guide with a longitudinal transport section and a transverse transport section for guiding light. The longitudinal transport section has a light entry surface arranged transversely to its longitudinal extent for coupling light from at least one light source into the longitudinal transport section and a light exit section along its longitudinal extent. The transverse transport section is formed as a flat surface with a first broad side, a second broad side opposite the first broad side, and narrow sides, and is connected to the longitudinal transport section at the light exit section along its longitudinal extent at a first narrow side.The longitudinal transport section has a lateral surface along which the coupled light is guided longitudinally by total internal reflection. The light couples through the light exit section into the transverse transport section and is guided by total internal reflection between the opposing broad sides of the transverse transport section. In the lighting devices disclosed in DE 100 32 927 A1 and DE 20 2016 100 986 U1, the transverse transport section has secondary deflection elements by which the light coupled into the transverse transport section is deflected such that it exits the surface spanned by the planar transverse transport section at at least one of the opposing broad sides.

[0005] From DE 10 2012 101 455 A1, an optical fiber with three lead arms is known, each having a light-entry surface at its first end. Each of these light-entry surfaces faces a light source associated with the respective lead arm. At their second end, furthest from the first end, the lead arms are connected to each other.

[0006] From US 2010 / 0 315 833 A1, a light guide with a longitudinal transport section is known which has a light entry surface facing a light-emitting diode at its first axial end and has a change in cross-section along its length, such that the cross-section of the longitudinal transport section decreases from the first axial end to the other axial end of the longitudinal transport section further away.

[0007] From JP 2008-74 262 A, an optical fiber with two longitudinal transport sections and one transverse transport section is known. A first longitudinal transport section is arranged on a first narrow side of the transverse transport section, and a second longitudinal transport section is arranged on the second narrow side of the transverse transport section opposite the first narrow side. Each longitudinal transport section has at least one light-entry surface arranged transversely to its longitudinal extent for coupling the light from a light-emitting diode associated with that light-entry surface.

[0008] US Patent 5,915,855 A discloses a light guide plate having a light entry surface on one narrow side. To guide the light entering the light guide through the light entry surface, a dot pattern is applied to the back of the light guide plate by screen printing.

[0009] EP 3 553 371 A1 describes the manufacture of a one-piece light guide having two longitudinal transport sections and one transverse transport section using a multi-component injection molding process.

[0010] For example, a motor vehicle with a light guide is known from DE 20 2016 003 741 U1. The light guide is used to indirectly illuminate the interior of the motor vehicle from a lighting device. An end face of the planar light guide serves as the coupling section for coupling the light into the light guide. To illuminate the interior of the motor vehicle, light is coupled out of the light guide, which is designed as a film, by means of an output coupling structure, thus enabling planar illumination.

[0011] A disadvantage of such side-firing arrangements is that uniform light emission from the film is only possible up to a limited distance from the light source, i.e., from one edge of the film. Since light cannot be projected arbitrarily far or deep into the film's light guide from the side or edge, the achievable film size is limited, at least if uniform brightness across the illuminated area is desired. This negatively impacts the efficiency of the lighting system. This arrangement is also unsuitable for specific installation requirements. A further disadvantage arises when RGB LEDs are used, as the light is not sufficiently mixed within the film before exiting.

[0012] The object of the invention is to create a simple-to-manufacture lighting device of the type mentioned above, which requires few components, has a small footprint, and is lightweight, in order to enable the desired light distribution in an interior space as efficiently as possible. Furthermore, the invention aims to enable simple, quick, and cost-effective mounting of the lighting device while ensuring a predetermined, homogeneous, and even light distribution within the interior.

[0013] This problem is solved with respect to the method by the features of claim 1 and with respect to the lighting device by the features of claim 5. Further developments are described in the dependent claims.

[0014] According to claim 5, the fact that the transverse transport section is connected to the longitudinal transport section along its longitudinal extent via at least one light-exit section has the advantage that the light can spread chaotically within the longitudinal transport section and is thus mixed, so that only homogeneous and well-mixed light passes into the transverse transport section. Because the transverse transport section is designed as a flat surface with narrow sides, it forms a surface luminaire for illuminating an interior space, which can also be used as a contour luminaire. The arrangement of the at least one light source on a light-entry surface positioned transversely to the longitudinal extent offers the advantage that the light is coupled in at the end face of the longitudinal transport section, allowing for a flexible installation arrangement of the lighting device.Flexible installation arrangement means that the light source and its electrical connections can be positioned adjacent to a limited installation space.

[0015] It is expedient that at least one transverse transport section has secondary deflection elements that make it possible to design a dedicated optic for the interior lighting in order to obtain not only homogeneous lighting, but also zonal illumination and dynamic lighting scenarios.

[0016] Because the longitudinal and transverse transport sections are formed as a single piece from a single material, the lighting device can be manufactured from the same material in a single injection molding process. Furthermore, the light output section is arranged as a seamless transition. Light transfer from the longitudinal to the transverse transport section occurs without any disruptive optical interference, resulting in higher efficiency. The lighting device is manufactured using injection molding, a cost-effective and time-saving process.

[0017] Because the transverse transport section is designed as a flat film and molded onto the longitudinal transport section, the transverse transport section can be processed cost-effectively as a prefabricated purchased part.

[0018] It is advantageous to arrange several spaced-apart transverse transport sections in a strip shape along the longitudinal transport section, so that in addition to saving material and weight, 3D shaping can also be made possible.

[0019] Advantageously, the transverse transport section is arranged in a radial plane to the central axis of the longitudinal transport section. Depending on the installation situation of the lighting device, it is advantageous to form the transverse transport section centrally along its longitudinal extent against the longitudinal transport section in order to utilize the space, for example, below the transverse transport section for mounting. In another installation situation, it may be advantageous to arrange the transverse transport section in a tangential plane to the surface of the longitudinal transport section. This results in a flush-mounted lighting device that is used for simple and space-saving installation.

[0020] Advantageously, at least one light source is designed as a single-color or multi-color LED, particularly an RGB LED. Using an LED as the light source allows for an energy-efficient lighting device that can illuminate an entire area with just one LED. Especially in electromobility applications, even the smallest energy savings have a positive impact on the vehicle's range. The RGB LED emits colored light into the longitudinal transport section, which spreads randomly and passes into the transverse transport section as mixed light. This provides the transverse transport section with homogeneously colored light, which is then extracted from the transverse transport section to illuminate the interior.Furthermore, the use of one or more RGB LEDs and at least one longitudinal transport section for mixing the multicolored LEDs offers an optical system with a variety of further possibilities, because the entire color space of the LEDs used is available as a color palette for specific settings.

[0021] Advantageously, a first light source is arranged at a first light-entry surface and a second light source at a second light-entry surface along the longitudinal length of an end section of the system, where at least one longitudinal transport section is used for coupling in the light, or where the end section is designed as a reflecting mirror. This arrangement creates even more intense illumination of the interior space to be lit.

[0022] Because the longitudinal transport section has at least one primary light entry surface with an associated primary light source and a supply arm with a primary end featuring an additional light entry surface with an associated secondary light source, and a secondary end merging into the longitudinal transport section, further light is coupled into the longitudinal transport section and thus into the planar transverse transport section. This allows not only for a more intense light distribution but also for a space-independent arrangement. The light source of the supply arm can be positioned further away from the transverse transport section if required by space constraints.

[0023] Advantageously, the longitudinal transport section has primary deflection elements that deflect the light guided in the longitudinal transport section in such a way that it couples into the transverse transport section through the at least one light exit section. The primary deflection elements can be arranged either within the volume of the longitudinal transport section or on its outer surface. This offers the advantage that the light transmission can be precisely controlled to influence the light distribution in the transverse transport section.

[0024] Preferably, the longitudinal transport section exhibits a change in cross-section along its length, such that the cross-section decreases continuously towards the end region, or decreases to a predetermined point and then increases again towards the end region, or is only tapered in the end region. The light, which reacts to the changes in cross-section, behaves accordingly. Because the cross-sectional area decreases continuously along the length of the longitudinal transport section, the light can enter the transverse transport section at the end region with the same intensity as at the initial coupling point. By implementing a partial reduction in cross-section over an arbitrary region along the longitudinal length, the light is coupled into the transverse transport section with a correspondingly high intensity at this constricted point.These changes in the cross-sectional area along the length of the longitudinal transport section result in a targeted transmission of light into the transverse transport section.

[0025] In a preferred embodiment of the invention, a further longitudinal transport section is arranged on the second narrow side opposite the first narrow side of the transverse transport section. This further longitudinal transport section has at least one additional light entry surface arranged transversely to its longitudinal extent for coupling light from at least one further light source into the longitudinal transport section, and at least one light exit section along its longitudinal extent, which is connected to the second narrow side of the transverse transport section. This arrangement increases both the light intensity and the dynamic light behavior in the transverse transport section. High light intensity is achieved when a total of four light sources are arranged on the two longitudinal transport sections such that light is coupled into the transverse transport section from each side via the light entry surface.Additionally, one or more supply arms with extra light-entry surfaces and corresponding light sources can be arranged. Since all light sources are connected to a single electrical connection, the number of components is reduced.

[0026] Because the transverse transport section has fastening elements that interact with the central fastening elements of a support beam in such a way that the transverse transport section and the support beam can be connected in a zone of the transverse transport section with low light intensity distribution, the advantage arises that the connection takes place precisely in the area or zone that plays a subordinate role in light distribution. This zone was previously calculated using a light simulation and varies for different designs due to structural requirements. Since a lower light intensity prevails in the zone areas, the central fastening elements, which are attached to the fastening elements of the transverse transport section, for example by clips, do not interfere with the light guiding process.

[0027] It is advantageous if the transverse transport section or the support has decentralized fastening elements, so that the transverse transport section and the support can be mechanically and securely connected to each other.

[0028] In a preferred embodiment of the invention, at least one decentralized fastening element is designed as a secondary deflection element. This has the advantage that all decentralized fastening elements also function as secondary deflection elements, and this dual function ensures that the fastening has no effect on the light guidance in the transverse transport section or on the light extraction. If the lighting device is exposed to higher temperatures, which can occur indoors, the plastic material from which the transverse transport section is made loses stiffness. This can lead to displacement of the fastening elements. If the fastening elements are congruent with the secondary deflection elements, this has no negative consequences for the light guidance, even if the lighting device loses dimensional stability due to heat, e.g., in the interior of a vehicle.

[0029] In a preferred embodiment of the invention, electronic components, in particular at least one sensor and a heating wire, are arranged in and / or on the transverse transport section. The lighting device can thus fulfill several functions that would otherwise require separate components in the vehicle. This results not only in weight savings but also in greater operator comfort.

[0030] The advantages of the method for manufacturing a lighting device according to claim 1 correspond to the advantages mentioned above with reference to the lighting device according to the invention.

[0031] Further details, features and advantages of the present invention will become apparent from the following description of a particular embodiment with reference to the schematic drawings.

[0032] It shows: Fig. 1 a perspective view of the lighting device, Fig. 1a - 1d different geometric designs and arrangements, Fig. 2 further embodiments according to Fig. 1 with beam path, Fig. 3a, b further embodiments of the lighting device, Fig. 4 View of an alternative embodiment, Fig. 5a a perspective view with central fixing, Fig. 5b a perspective view with decentralized fastening, Fig. 6a - 6c further embodiment according to Fig. 5, Fig. 7 Top view of lighting device, Fig. 8 Lighting device with decoration Fig. 9 further embodiments according to Fig. 8 and Fig. 10. Perspective view of an alternative embodiment.

[0033] The in Fig. The lighting device shown in Figure 1 is designated in its entirety by reference numeral 100 and comprises a longitudinal transport section 200 and an associated transverse transport section 300. The longitudinal transport section 200 extends from a light-entry surface 210 to an end region 220, which faces away from the light-entry surface 210. The transverse transport section 300 projects laterally along this longitudinal extension L.

[0034] The transverse transport section 300 extends over a flat surface and has a first broad side 320, a second broad side 330 opposite it, and corresponding narrow sides surrounding it. One broad side, in this embodiment the first broad side 320, is designed so that light can escape into an interior space, while the opposite broad side, here the second broad side 330, faces away from the interior space and can serve, for example, for attachment to a support. In this embodiment, the transverse transport section 300 is connected to the longitudinal transport section 200 at a light-exit section 230 via a narrow side 350 and projects transversely from it.This connection can be made of a single material if both sections 200 and 300 are manufactured using injection molding from a lightweight, transparent plastic material such as PC or PMMA, or it can be formed by a material bond if the longitudinal transport section 200 is injection-molded onto the transverse transport section 300. The transverse transport section 300 can be prefabricated as a film made of a material such as PC or PMMA. In the transverse transport section 300, both in the film and in the material-molded transverse transport section 300, secondary deflection elements 340 are arranged according to the application, so that the light is extracted from one side of the transverse transport section 300 at the desired locations. If the lighting device 100 is manufactured using injection molding and is made of a single material, the secondary deflection elements 340 can be integrated directly into the mold.In this illustration, the secondary deflection elements 340 are arranged on the second broad side 330 facing away from the interior; they can also be placed inside, i.e., within the volume of, the transverse transport section 300. With this one-sided coupling of the light into the transverse transport section 300, the film hangs loosely and flexibly from the longitudinal transport section 200 and can be flexibly positioned within the interior.

[0035] The light from a first light source 205 is coupled into the light entry surface 210 of the longitudinal transport section 200 and propagates by total internal reflection along the lateral surface M within the longitudinal transport section 200 in the direction of its longitudinal extent L. In this embodiment, the light propagates from the light entry surface 210 to the end region 220. Because the transverse transport section 300 is connected to the longitudinal transport section 200 at a narrow side 350 along its longitudinal extent L, a light exit section 230 is formed, at which the coupled light exits the longitudinal transport section 200 and enters the transverse transport section 300. In the transverse transport section 300, the light is guided between a first broad side 320 and the opposite second broad side 330, since the light also undergoes total internal reflection here.For the targeted extraction of light, secondary deflection elements 340 are arranged in the transverse transport section 300. In this illustration, the deflection elements 340 are arranged on the second broad side 330 facing away from the interior, so that the light exits through the first broad side 320 and is coupled into the interior to be illuminated. The longitudinal transport section 200 is not limited to the straight path shown here; it can also have a curved path.

[0036] The first light entry surface 210, as well as the further light entry surfaces 209, 211, 212 and 213 (not shown here), are designed to capture as much light as possible from their respective assigned light source. Each of the light sources can be a monochromatic or multichromatic LED light source. If an RGB LED is used as the point light source, it is necessary that only well-mixed light is emitted into the interior to be illuminated in order to ensure a homogeneous appearance. According to the invention, this is achieved by first mixing the light from the RGB LED with its color components in the longitudinal transport section 200 by total internal reflection at the lateral surface M, and then allowing only homogeneous, well-mixed light to enter the transverse transport section.

[0037] The geometric cross-sectional shapes of the longitudinal transport section 200 are in Fig. Figure 1a shows the longitudinal transport section 200. Depending on the requirements and installation situation, it can be shaped in various ways, such as circular, oval, rectangular, or square. The diameter of the longitudinal transport section 200 is preferably between 1 mm and 10 mm, and ideally between 2 mm and 5 mm. The diameter is determined based on the distance the light has to travel. Furthermore, the diameter of the longitudinal transport section 200 is determined based on the thickness of the transverse transport section 300. The amount of light passing through the light exit section 230 can be regulated by the geometric relationship between the longitudinal transport section 200 and the transverse transport section 300.

[0038] Fig. Figure 1b shows the longitudinal transport section 200 as it undergoes a change in cross-sectional area along its longitudinal extent L. Starting from the light entry surface, here exemplified by the first light entry surface 210, the cross-sectional area can be monotonically tapered along its longitudinal extent L towards the end region 220. Another embodiment provides that the cross-sectional area only tapers in the end region 220. Furthermore, Figure 1b shows... Fig. 1b A preferred embodiment in which the narrowing of the longitudinal transport section 200 occurs approximately midway between the first light entry surface 210 and the end region 220. At this constriction, where the cross-sectional area is smallest, the light is coupled into the transverse transport section 300 with a higher intensity. The longitudinal transport section 200 may also have a curved shape.

[0039] In Fig. Figure 1c shows the arrangement of the transverse transport section 300 on the longitudinal transport section 200. The transverse transport section 300, with its two broad sides 320, 330, can be arranged centrally along the longitudinal extension L of the longitudinal transport section with its first narrow side 350 at the light-exit section 230 of the longitudinal transport section 200. In another embodiment, the transverse transport section 300 can be arranged on the longitudinal transport section 200 such that the two sections form a flat plane, which is advantageous when installing the lighting device 100 on flat surfaces, such as interior door panels. The transverse transport section 300, with its two broad sides 320, 330, extends in a tangential plane to the longitudinal transport section 200. The longitudinal transport section 200 is connected to the first narrow side 350 of the transverse transport section 300 at the light-exit section 230.

[0040] The respective shaping of the transverse transport section 300 on the longitudinal transport section 200 has no effect on the effect of the lighting of the interior, since the light emission from one of the broad sides 320, 330 is not affected by this.

[0041] Fig. Figure 1d shows a further embodiment of the lighting device 100 according to the invention. In this embodiment, the light is coupled into the longitudinal transport section 200 not only via the first light entry surface 210, but also from an additional light source 204 via an additional light entry surface 209, which is associated with a supply arm 201. The supply arm 201 is connected to the longitudinal transport section 200 at its end opposite the light entry surface 209. The arrangement at the first light entry surface 210 is shown here only as an example. Such an arrangement can be added to each of the light entry surfaces 211, 212, and 213. This allows the light coupling to be designed with the aim of achieving efficient light intensity, which in turn promotes a homogeneous appearance. The light can already undergo one or more total internal reflections in the supply arm 201 and, if an RGB LED is used, can be well mixed.

[0042] For the sake of simplicity, the longitudinal transport section 200 is shown below as a circular cylindrical strand. However, the various configurations of the geometric designs mentioned above are possible.

[0043] Fig. Figure 2 shows a further embodiment in which a second light-entry surface 211 with an associated second light source 206 is arranged in the end region 220 of the first longitudinal transport section 200. The light is coupled into the light-entry surface 211 opposite the longitudinal extent L and propagates, as already described in the figure description. Fig. Figure 1 explains this under the conditions of total internal reflection. By arranging a second light source 206 on the longitudinal transport section 200, the light path acquires a dynamic behavior that can be advantageously used for interior lighting. The schematically represented path of the light shows the light being extracted from the longitudinal transport section 200 into the transverse transport section 300 at the light exit section 230. Primary deflection elements 240 can be embedded in the surface or volume of the longitudinal transport section 200, causing a stronger light transfer from the longitudinal transport section 200 into the transverse transport section 300. These primary deflection elements 240 can be arranged at regular intervals or in groups along the longitudinal extent L of the longitudinal transport section. This results in a controlled light transfer, especially in the initial region of the transverse transport section 300.When using RGB LEDs as a point light source, arranged on a semiconductor chip with their individual colors, the light is not emitted from a single point, but from, for example, three points. The RGB LED thus emits chaotic light into the longitudinal transport section 200, which mixes the coupled light uniformly. As a result, the light emerges as homogeneous colored light from the longitudinal transport section 200 into the transverse transport section 300 and then into the interior space to be illuminated.

[0044] By using multiple light sources, in this case two light sources 205 and 206, located at one end of the longitudinal transport section 200 with the first light entry surface 210 and at the opposite end with the second light entry surface 211, an interior lighting with enhanced perceived value is achieved, whereby the amount of light exiting the transverse transport section 300 can be predetermined as desired. This results in an optical effect that can be precisely tailored to the desired ambiance.

[0045] The secondary deflection elements 340 can be designed as an engraved laser structure, a printed pattern or disturbances in the volume of the transverse transport section 300.

[0046] Further embodiments of the lighting device 100 according to the invention, comprising a light guide having at least one longitudinal transport section 200 and at least one transverse transport section 300, are described in Fig. Figure 3 shows that the arrangement of longitudinal transport section 200 to transverse transport section 300 can be arbitrary.

[0047] Fig. Figure 3a shows, by way of example, a longitudinal transport section 200 with two transverse transport sections 300 arranged perpendicular to its longitudinal extent L. Depending on the requirements of the interior to be illuminated, the arrangement can be extended as desired. Also shown, by way of example in this embodiment, are two light entry surfaces 210, 211 with the associated light sources 205, 206 arranged on the longitudinal transport section 200.

[0048] Fig. Figure 3b shows an arrangement of a transverse transport section 300 between two longitudinal transport sections 200. Each longitudinal transport section 200 has two light entry surfaces 210 to 213, each with a light source 205, 206, 207, and 208. In this preferred embodiment, the interior is maximally illuminated when light exits from the broad side, and only one connection part is required for the four light sources. The light coupling can be designed differently in this embodiment than shown. For example, one end can be configured as a reflecting mirror or with a supply arm 201.

[0049] In Fig. Figure 4 shows a plurality of transverse transport sections 300. These multiple strip-shaped transverse transport sections 300 are arranged section by section along the longitudinal transport section 200 in its longitudinal extent L and project transversely from it. Each transverse transport section 300 is attached to a light exit section 230, at which the light from the longitudinal transport section 200 passes into the transverse transport section 300. For targeted light coupling into the strip-shaped transverse transport sections 300, the primary deflection elements 240 can be arranged in the volume or on the lateral surface M of the longitudinal transport section 200 on the circumferentially opposite side of the light exit areas 230. As already described in the section on Fig. As mentioned in Figure 1, the strip-shaped transverse transport sections 300 can be injection-molded together with the longitudinal transport section using the same material or inserted into the injection mold as strip-shaped film sections before the at least one longitudinal transport section 200 is injection-molded. This special design enables cost-effective 3D shaping, as the lighting device 100 with the transverse transport section 300 can flexibly adapt to the geometry or three-dimensional structure of a vehicle's interior.

[0050] Fig. 5a and Fig. Figure 5b shows exemplary embodiments of the lighting device 100 according to the invention, comprising two longitudinal transport sections 200 and a planar transverse transport section 300, the narrow sides 350, 360 of which are integrally formed with the longitudinal transport sections 200. The first light source 205 is arranged on a first longitudinal transport section 200 and couples light into the longitudinal transport section 200 via the light entry surface 210. Light is coupled into the further longitudinal transport section 200 by means of a further light source 208. For this purpose, the longitudinal transport section 200 is provided with a further light entry surface 213. The light propagates along the respective longitudinal transport section 200 by means of total internal reflection and passes into the planar transverse transport section 300.In this embodiment as well, the light transmission can be selectively controlled by means of primary deflection elements 240, so that, for example, the light transmission occurs only in a light exit section 230. The light exit section 230 is shown schematically across the entire width of the narrow sides 350, 360. However, it can also be arranged over a smaller area, for example, only at the beginning of the light coupling, so that the light transmission is selective. The light enters the transverse transport section 300 from two narrow sides 350, 360 and propagates between the broad sides 320, 330 also by total internal reflection in the transverse transport section 300. The light output into the interior to be illuminated is controlled by the secondary deflection elements 340.

[0051] Fig. Figure 5a shows a mounting method for the lighting device 100 according to the invention, which causes very little disturbance in the light guiding process.

[0052] To enable the lighting device to be mounted in the interior, for example of a motor vehicle, a carrier 400 is provided. The carrier 400 can also be designed as a reflector to achieve higher efficiency and thus enhance the interior lighting. Central fastening elements 410 can be formed on the carrier 400, to which the transverse transport section 300 is attached, for example by clipping or welding. Alternatively, the central fastening elements 410 can be arranged on the transverse transport section 300, for example by injection molding, to attach it to the carrier 400.To ensure a homogeneous and even distribution of light inside the vehicle without disrupting the light guidance process during mounting, the central mounting elements 410 are connected to corresponding areas of the transverse transport section 300 located in a zone 370 with minimal light intensity. This zone 370 is shown here as an example of a narrow strip in the center of the transverse transport section 300. However, zone 370 can be located at any point within the transverse transport section 300, either as a single area or as several individual sub-areas. The area to be selected as zone 370 for mounting depends on the application and can be determined by simulating the light guidance process. This avoids undesirable interference points that would negatively affect the light guidance.The central fastening elements 410 are designed with a thickness that allows them to act as spacers between the carrier 400 and the transverse transport section 300. This creates an air gap which, due to its refractive index, causes total internal reflection within the transverse transport section 300. The central fastening elements 410 can be designed as white or colored dots, studs, or ribs that simultaneously act as an adhesive without interfering with the light-guiding process. Alternatively, the fastening can be implemented as a welded connection. If the central fastening elements 410 are arranged on the transverse transport section and the complementary fastening elements 380 are on the carrier, the central fastening elements can be attached to the transverse transport section during the injection molding process. The structure of the central fastening elements 410 can be uniform or irregular, depending on the requirements of the interior to be illuminated.Regardless of the mounting method, the structure and / or pattern of the light output can be individually adapted to the interior decor using the secondary deflection elements 340.

[0053] For fastening the lighting device 100 according to the invention, the transverse transport section 300 can be designed such that it extends in the longitudinal direction L of the longitudinal transport sections 200 beyond the light output section 230 with a fastening section 310, see Fig. 5b. The fastening section 310 can also extend beyond the respective light entry surfaces 210, 213 and / or beyond the opposite end areas 220 in order to provide for the fastening of the lighting device 100 to, for example, a decorative carrier on these projecting areas.

[0054] These forms of fastening have in common that the fastening areas 310 lie outside the light guide and therefore have no disruptive effect on the illumination or the light guiding process. The fastening areas 310 are light-tight. The transverse transport section 300 can be connected to other components, such as the carrier 400 shown here, by welding, gluing, or clipping. A connection by clipping the central fastening elements 410 and the interacting fastening elements 380 is shown only schematically. Due to the arrangement of the fastening areas 310 according to the invention, fastening the lighting device 100 is not associated with a loss of light intensity.

[0055] Further mounting options, depending on the specific requirements or lighting application, are described in Fig. 6 schematically represented.

[0056] To achieve higher efficiencies, a reflector 400 is arranged on one of the broad sides 330. For a thin housing, the use of a thin film as a highly reflective reflector 400 is advantageous. If this reflector 400 is glued across its entire surface to the broad side 330 of the transverse transport section 300, the total internal reflection ceases in the transverse transport section 300, and the light does not propagate as desired between the first broad side 320 and the second broad side 330. As already described in the section on Fig. As explained in section 5, in the case of a partial connection of the carrier or reflector 400 with the transverse transport section 300, a minimal air gap may still be present, which does not impair total reflection.

[0057] Fig. Figure 6b shows a light distribution that corresponds to a desired emission into the interior. If the decentralized fastening elements 420 are arranged for the connection between 300 and 400 according to the desired light distribution, a secondary deflecting element 340, which would otherwise have to be applied to the first broad side 320 of the transverse transport section 300, is no longer necessary. This dual function of the decentralized fastening elements 420, namely to act as a connection and as an optical interference point like a secondary deflecting element 340, can be specifically exploited to obtain the desired light distribution pattern.

[0058] In Fig. Figure 7 shows how the lighting device 100 can be used for multiple purposes in addition to area or contour lighting. For this purpose, electronic components, such as sensors 500 or heating wires 510, are arranged in or on the transverse transport section 300. The sensors 500 can be designed for touch-sensitive control of individual switch functions. An additional heating function can be enabled by welding, melting, or bonding a heating wire 510 to the transverse transport section 300. Alternatively, a thin-wire heating element can be applied using thin-film technology, in particular PVD (physical vapor deposition) coating. For such applications, the heating wires 510 can also be at least partially replaced by the thinner conductor tracks applied using PVD technology.

[0059] These additional functions of the lighting device 100 are preferably integrated into vehicle trim in electrically powered passenger cars, such as door panels, center consoles, and even the vehicle roof. If the lighting device 100 is also used for heating the interior, this contributes to increased energy efficiency and / or extended range of the electrically powered vehicle, as the energy consumption is lower than with conventional heating systems. Advantages of this multifunctional embodiment include the small number of components and the resulting reduced weight.

[0060] As from the Fig. 8 and Fig. As can be seen in Figure 9, the lighting device 100 according to the invention can be used for further applications. As already mentioned in the preceding description, the light from the light sources 205, 206 is coupled into the longitudinal transport section 200 and coupled out into the transverse transport section 300 via a light exit section 230. The light output can also take place along the longitudinal extension L on the other side of the longitudinal transport section 200, so that two transverse transport sections 300 are supplied with light from the light sources 205, 206 by one longitudinal transport section 200, which is not shown here. The light propagates by means of total internal reflection between the broad sides 320, 330. In doing so, it is refracted at the secondary deflection elements 340, as already described, and exits on one broad side to, for example, backlight the first decoration 600.The residual light arriving at the second narrow side 360 ​​of the transverse transport section 300 can be used not only for contour illumination of this narrow side 360, but also for illumination of a second decoration 610. For this purpose, the residual light is coupled out of the transverse transport section 300 at the light transfer section 620 and coupled into the second decoration 620.

[0061] Fig. 9a and Fig. Figure 9b shows the lighting device 100, which is arranged behind a non-structured decorative carrier, or rather, a transparent first decorative layer 600, which is backlit. On the broad side 320 of the transverse transport section 300, a first layer 630 with partially opaque areas and a second layer 640, which is designed, for example, as a metal layer, are applied. To the viewer, a metallic effect is visible behind the first decorative layer 600 when unilluminated, and only when the lighting device 100 emits light does the desired pattern created by the first layer 630 become visible.

[0062] Another preferred embodiment is described in Fig.Figure 10 illustrates this. Two lighting devices 100 are arranged one above the other in such a way that a combination of contour and surface lighting is created. The second narrow side 360 ​​of one lighting device 100 is designed as contour lighting, so that light is emitted and the viewer perceives a strip of light. The second lighting device 100 backlights the decor 600 across its entire surface. Reference symbol list 100 lighting device 200 Longitudinal transport section 201 Supply arm 204 additional light source 205 first light source 206 second light source 207, 208 further light source 209 additional light entry area 210 first light entry surface 211 second light entry surface 212, 213 additional light entry area 220 end range 230 Light output section 240 primary deflection element 300 Cross transport section 310 Fastening section 320 first broadside 330 second broadside 340 secondary deflection element 350 first narrow side 360 second narrow side 370 Zone 380 fasteners 400 carriers, reflector 410 central fastening elements 420 decentralized fastening elements 500 Sensor 510 heating wire 600 first decor 610 second decor 620 Light transmission section 630 first shift 640 second shift L Longitudinal extent M surface area Q transverse direction

Claims

Method for manufacturing a lighting device (100), comprising the following steps: - providing an injection mold with at least one first cylindrical cavity for filling with an injection molding material; - inserting a transverse transport section (300) in the form of a planar film with a first narrow side (350) into the cylindrical cavity along a longitudinal extent (L) of the first cylindrical cavity; - filling the at least first cylindrical cavity to produce a longitudinal transport section (200) with a lateral surface (M) along which the coupled light is guided by total internal reflection in the longitudinal transport section (200) along its longitudinal extent (L), and to join the first narrow side (350) of the planar film with the injection molding material of the longitudinal transport section (200);- Introducing secondary deflection elements (340) on the surface and / or in the volume of the transverse transport section (300) and - Arranging at least one light source, in particular an RGB LED, on at least one coupling surface of the longitudinal transport section (200).; Method according to claim 1, characterized in that the secondary deflection elements (340) are distributed on or in the transverse transport section (300) in the manner of a point matrix calculated for a desired light distribution. Method according to claim 1 or 2, characterized in that the secondary deflection elements (340) are applied to the at least one broad side (320, 330) of the transverse transport section (300) by means of a printing process. Method according to one of claims 1 to 3, characterized in that at least one secondary deflection element (340) is designed in the form of decentralized fastening elements (420). Lighting device (100) for illuminating an interior space, comprising a light guide with at least one longitudinal transport section (200) and at least one transverse transport section (300) for guiding light, wherein the at least one longitudinal transport section (200) has at least one light entry surface arranged transversely to its longitudinal extent (L) for coupling light from at least one light source into the longitudinal transport section (200) and at least one light exit section (230) along the longitudinal extent (L), wherein the at least one transverse transport section (300) is designed with a planar first broad side (320), a second broad side (330) opposite the first broad side (320) and narrow sides and is connected at at least one first narrow side (350) to the at least one longitudinal transport section (200) along the longitudinal extent (L) at the at least one light exit section (230),- wherein the longitudinal transport section (200) has a lateral surface (M) on which the coupled light is guided by total internal reflection in the longitudinal transport section (200) in its longitudinal extent (L), wherein the light couples through the at least one light exit section (230) into the at least one transverse transport section (300) and is guided by total internal reflection in the latter between the opposing broad sides (320, 330) of the transverse transport section (300),- wherein the at least one transverse transport section (300) has secondary deflection elements (340) on which the light coupled into the transverse transport section (300) is deflected such that it exits the surface spanned by the planar transverse transport section (300) at at least one of the opposing broad sides (320, 330), characterized in thatthat the transverse transport section (300) is designed as a planar film and the lighting device was manufactured by a method according to one of the preceding claims. Lighting device (100) according to claim 5, characterized in that several spaced-apart transverse transport sections (300) are arranged in a strip shape on the longitudinal transport section (200) in longitudinal extension (L). Lighting device (100) according to claim 5 or 6, characterized in that the transverse transport section (300) is arranged in a radial plane to the central axis of the longitudinal transport section (200) or in a plane tangential to the lateral surface (M) of the longitudinal transport section (200). Lighting device (100) according to one of claims 5 to 7, characterized in that a first light source (205) is arranged at a first light entry surface (210) and a second light source (206) is arranged at a second light entry surface (211) in longitudinal extension (L) at the end of an end region (220) of the at least one longitudinal transport section (200) for coupling in light or that the end region (220) is designed as a reflection mirror. Lighting device (100) according to one of claims 5 to 8, characterized in that the longitudinal transport section (200) has at least one first light entry surface (210) with associated first light source (205) and a supply arm (201) which has a first end at which an additional light entry surface (209) with associated additional light source (204) is arranged and the second end of which transitions into the longitudinal transport section (200). Lighting device (100) according to one of claims 5 to 9, characterized in that the longitudinal transport section (200) has primary deflection elements (240) at which the light guided in the longitudinal transport section (200) is deflected in such a way that it couples through the at least one light exit section (230) into the transverse transport section (300). Lighting device (100) according to one of claims 5 to 10, characterized in that the longitudinal transport section (200) has a change in cross-section in its longitudinal extension (L) such that the cross-section decreases continuously towards the end region (220) or decreases to a predetermined point and increases again towards the end region or is only tapered in the end region (220). Lighting device (100) according to one of claims 5 to 11, characterized in that a further longitudinal transport section (200) is arranged on the second narrow side (360) opposite the first narrow side (350) of the transverse transport section (300), wherein the further longitudinal transport section (200) has at least one further light entry surface (213) arranged transversely to its longitudinal extent (L) for coupling light from at least one further light source (208) into the longitudinal transport section (200) and at least one light exit section (230) along its longitudinal extent (L) which is connected to the second narrow side (360) of the transverse transport section (300). Lighting device (100) according to one of claims 5 to 12, characterized in that the transverse transport section (300) has fastening elements (380) which cooperate with central fastening elements (410) of a carrier (400) in such a way that the transverse transport section (300) and the carrier (400) can be connected to each other in a zone (370) of the transverse transport section (300) with low light intensity distribution. Lighting device (100) according to one of claims 5 to 13, characterized in that the transverse transport section (300) or the support (400) has decentralized fastening elements (420) so that the transverse transport section (300) and the support (400) can be mechanically connected to each other in a materially bonded manner. Lighting device (100) according to claim 14, characterized in that at least one decentralized fastening element (420) is designed in the form of a secondary deflection element (340). Lighting device (100) according to one of claims 5 to 15, characterized in that electronic components, in particular at least one sensor (500) and one heating wire (510), are arranged in and / or on the transverse transport section (300).

Images