LIGHTING UNIT WITH FLEXIBLE SURFACE LIGHTING BODY

Description

[0001] The invention relates to a lighting unit with a flexible surface lighting body, which has a plurality of light sources distributed over a surface on a flat carrier material, which comprises a flexible, in particular textile-based, flat circuit carrier, which is equipped on a front side with the plurality of light sources which are interconnected by electrical lines formed in or on the circuit carrier.

[0002] Corresponding surface lighting fixtures are marketed by the applicant, among others, under the name Carpetlight and are described, for example, in German patent DE 10 2014 206 882 B4. They are designed for various applications, such as area illumination in photography, film, and television production. Particularly in the latter fields, continuous illumination with high luminous intensities is required, which in most cases is achieved by systems of spotlights, reflectors, and diffusers. To illuminate changing scenes, the lighting system components used must be flexibly combinable, positionable, and adjustable.In DE 10 2014 206 882 B4, it is proposed to provide a flexible surface lighting body which has a plurality of light sources distributed over a surface on a surface carrier material which has at least two layers, wherein a first layer is designed as a textile-based flexible surface circuit carrier which is equipped on a front side with the plurality of light sources which are interconnected by electrical conductors formed in or on the circuit carrier, wherein a second layer is designed as a flexible surface cooling layer and is connected to the circuit carrier at its rear side opposite the front side.

[0003] In simple terms, such a surface lighting fixture is a self-illuminating sheet that is flexible, rollable, foldable, rotatable, and crushable, and which has a luminosity distributed across its surface sufficient, for example, to illuminate a scene or part of a scene. These "sheets" or flexible surface lighting fixtures can be manufactured in any size and are therefore easy to assemble. Because their flexibility and surface area are similar to those of familiar reflectors and diffusers, they are suitable for replacing the conventional combinations of spotlights, reflectors, and diffusers. They also require less light output, since their entire luminous intensity is available to illuminate a given scene and is not, as with conventional spotlight systems, only partially deflected and diffused towards the scene.This also leads to a reduction in the waste heat generated.

[0004] WO 2020 / 010243 A1 discloses a flexible lighting panel comprising a substrate with a conductor pattern and openings, solid light emitters electrically connected to the conductor pattern, a translucent first protective layer covering at least part of a first surface of the substrate, and a second protective layer covering at least part of a second surface of the substrate. The first and second protective layers are connected to each other through the openings and the perimeter of the substrate to assist in holding the translucent first and second protective layers in contact with the first and second surfaces of the substrate, respectively. One or both of the first and second protective layers encapsulate the solid light emitters. The lighting panel is flexible to allow opposite edges of the panel to be folded over each other and / or the panel to be rolled into a tubular configuration.

[0005] US patent 2020 / 0149714 A1 describes a lighting system with connections for signal and power transmission. This system allows for the use of multiple interconnectable flexible light panels, each containing several LED elements, with connecting elements, such as push buttons, providing strain relief.

[0006] CN 108205987 A reveals an LED softboard for an advertising display rack. A backlit mesh is stretched across the front of a frame. The backlighting is provided by a flexible LED panel with numerous LEDs. This LED panel is also clamped within the frame.

[0007] US patent 2016 / 0091185 A1 discloses a lightweight, portable, and flexible light bank with LED strips attached to a fabric and featuring a hook-and-loop fastening system for attaching to various objects. The light bank can be rolled up and folded. Batteries can be removed and attached to the back of the light bank.

[0008] In contrast to this prior art, the object underlying the invention is to provide a lighting unit that allows for more flexible use than before.

[0009] This problem is solved by a lighting unit comprising a flexible area lighting body having a plurality of light sources distributed over a planar substrate, which includes a flexible, in particular textile-based, planar circuit carrier equipped on a front side with the plurality of light sources connected by electrical conductors formed in or on the circuit carrier, and a control unit configured for supplying power and controlling the plurality of light sources, wherein the control unit comprises a housing arranged at an edge of the area lighting body and mechanically connected to it, wherein the edge of the area lighting body is sectionally received in the housing of the control unit, wherein the housing contains electrical and electronic components and conductors connected to the electrical conductors of the area lighting body.and comprises a strain relief device that absorbs tensile stresses between the housing of the control unit on the one hand and the surface lighting element on the other hand and keeps them away from the electrical connections between the control unit and the surface lighting element, wherein the strain relief device is designed to create a tensile-resistant connection between the material of the surface lighting element and the housing, wherein the lighting unit is further developed in that the strain relief device is designed as a clamping device, as a series of strain-receiving pins which are guided in the surface lighting element by a series of eyelets designed to suit the arrangement of the strain-receiving pins, as spacers with internal threads and screws which are screwed or screwable into the internal threads of the spacers, or as a cover which is screwed or screwable onto or attached to the housing or clamped or clampable.

[0010] The invention is based on the concept of integrating the surface lighting element and the control unit into a single lighting unit, making this unit robust and cable-free by means of a tensile-resistant connection between the surface lighting element and the control unit housing. Such a unit can be used in a variety of situations. For example, the lighting unit can be transported rolled up or wrapped and then unrolled and hung, attached with Velcro, laid out, etc., wherever it is needed, depending on the specific circumstances and available mounting options. An external power supply is not necessary if it is already integrated into the control unit. However, the control unit can also have a connection for an external power supply, regardless of whether a power supply is integrated.

[0011] Examples of applications for the lighting unit according to the invention would include the illumination of tents, including temporary tents, in the military, in disaster relief or in mobile medical facilities, in police operations for illuminating accident scenes, as well as for private use, and also for photographers who need mobile, area-wide lighting outside their studios that can be set up quickly. This list is not exhaustive.

[0012] Preferably, the circuit carrier is textile-based, in particular based on synthetic fibers, or alternatively designed as a flexible film, in particular polymer-based, especially polyimide or polyurethane. These materials offer, among other things, high flexibility and low weight while providing good resistance.

[0013] The strain relief element is designed according to the invention to create a tensile-resistant connection between the material of the surface lighting element and the housing. This means that there is a direct, tensile-resistant connection between the surface lighting element and the housing.

[0014] According to the invention, the strain relief device is also designed as a clamping device, as a series of strain-receiving pins guided in the surface lighting body by a series of eyelets designed to match the arrangement of the strain-receiving pins, or as a spacer with internal threads and screws that are screwed or screwable into the internal threads of the spacers, or as a cover that is screwed or screwable onto the housing, or clamped or clampable. In embodiments, the strain relief device is designed with a stop strip attached to the surface lighting body, which is designed to prevent the surface lighting body from being pulled out of the cover. Preferably, the carrier material is reinforced in the area of ​​the eyelets or the spacers, in particular by a double layer of the flexible, flat circuit carrier.Such a clamping device can grip the surface lighting element section by section from one or both sides and be equipped with a non-slip surface or profile, for example, with a rubber coating or a barbed or grooved profile. A simpler, but equally effective embodiment is a series of pins or studs that run transversely to the surface of the light source through eyelets along its edge. The clamping pins or studs are part of the control unit housing or at least permanently connected to it.

[0015] The electrical lines between the control unit and the light sources can be continuous, i.e., without interruption, and their respective ends can be directly connected, for example by soldering, to the corresponding contacts of the control unit and the light sources. Alternatively, the electrical lines can have an interruption with a contact point, which is located particularly in the area of ​​the strain relief device. This contact point is specifically designed as a spring-loaded pin contact with spring pins and opposing contact surfaces, which are contacted and secured by fastening the strain relief device, or as a pin header with contact pins that can be inserted into or are inserted into corresponding contact pin receptacles.

[0016] A spring-loaded pin connection provides reliable electrical contact even under mechanical stress because the pins have some play relative to their opposing contact surfaces. Since the pins have a spring-loaded tip, limited gaps between the parts being contacted, even those caused by excessive tension, can be tolerated without interrupting the electrical connection. The pins can also be configured as pin strips, and the contact surfaces as contact cups.

[0017] The spring-pin contact can be designed such that a textile surface light source has a pre-circuit board in the area of ​​the transition to the control unit. This pre-circuit board provides the contact surfaces for the spring-pins and, if necessary, the strain relief elements. The contact surfaces and spring-pins can, in particular, be arranged between the strain relief elements, which are designed to press the pre-circuit board and a circuit board of the control unit together. This ensures a secure spring-pin contact. A suitable strain relief element in this case is a combination of spacers with internal threads on one of the two circuit boards and through-holes or openings for screws that engage in the internal threads of the spacers. The corresponding openings may penetrate several or all layers of the surface light source.

[0018] Other strain relief devices can include rivets, SMD standoffs (surface-mount devices) with or without threads, or bolts for connecting the circuit boards. In further embodiments, the contacting can be configured such that a sub-circuit board on the textile has SMD sockets mounted on its upper surface, into which SMD pins from the main circuit board are inserted. This can be done with the circuit boards arranged vertically, one above the other, or horizontally, side by side. The mechanical strain relief corresponds to that described above. The strain relief can be implemented alone or in addition to the strain relief methods described above.

[0019] A simple and cost-effective contacting method involves using a pin header with contact pins that fit into corresponding pin receptacles. Since the pins of the pin header are parallel, the contact must be loaded in the direction of the pin alignment. In an advantageous embodiment, this is achieved by mounting the pin header in a cover that is screwed or clamped to the housing of the lighting unit. For this purpose, the housing has a corresponding contact strip with receptacles for the pins of the pin header, as well as for matching screws or clamps that interact with corresponding screws or clamps on the cover.

[0020] InIn further embodiments, the strain relief can be designed such that the covering of the surface lighting element supporting the light source, in particular a textile one, or the surface lighting element itself, has stop strips, in particular keder strips, metal strips, or plastic strips, with a particularly round, square, triangular, or elliptical cross-section, at its or its end edges facing the housing. These stop strips are fixed behind a slid-on attachment or frame on the housing. The stop strips are sewn, glued, or laminated to the surface lighting element, in particular to layers that enclose the inner textile circuit carrier. A seal against water and environmental influences on the inner module, in particular the laminated or coated one, is achieved by means of a clamping seal at the edge of the actual housing, thus making the housing a single-chamber system.

[0021] In embodiments with a stop strip or strips, the surface lighting element remains completely or largely outside the already waterproof housing. The stop strips are arranged parallel to the housing wall outside the housing. Subsequently, an attachment or frame, for example made of plastic, metal, or other suitable materials, with a central recess that can be optically sealed by upper and lower flexible rubber lips, is pulled over the surface lighting element and connected to the housing. The attachment or frame is then positioned in front of the stop strips in such a way that they remain in the space between the housing and the attachment or frame and cannot protrude through the central recess of the frame, even under tension. This attachment or frame can be connected to the housing by means of clamps and / or screws.The frame can also be formed by an upper and a lower half-shell that extend over the stop strips and fix them against being pulled out.

[0022] In certain embodiments, the surface-mounted light source features a flexible, flat cooling layer on the rear side of the circuit carrier, which is mechanically or materially bonded to the circuit carrier, and / or a rain- and dirt-repellent layer. In particular, the cooling layer is shielded from the outside by the rain- and dirt-repellent layer or is itself designed as a rain- and dirt-repellent layer. A ripstop fabric is particularly suitable as a rain- and dirt-repellent layer. The cooling layer has the property of dissipating the waste heat generated during operation of the light source more effectively than if the cooling layer were absent. Materials with increased thermal conductivity are particularly suitable, for example, fabrics containing metallic fibers or metallic coatings, and which either consist entirely of these materials or contain an admixture thereof.The effect is particularly noticeable in the fact that the light sources, for example LEDs, heat up less than in the case without a cooling layer.

[0023] In further embodiments, the surface lighting element has a diffusion layer and / or a directional grid on one front side of the circuit carrier, which is particularly removable. A diffusion layer, also called a diffuser, is a fabric or other layer that ensures a uniform illumination and distributes a portion of the intensity generated directly at the location of the light sources into the area between the light sources, optionally forming a certain directional characteristic of the emitted light that may differ from the original directional characteristic of the light sources themselves. This can lead to further distribution. A directional grid can narrow this directional distribution again, achieving a very uniform and simultaneously directional illumination, particularly in combination with the diffusion layer.Additionally or alternatively, a layer of cotton wool can be used, especially between the diffuser and the light sources, which provides both diffusion and mechanical protection. The diffusion layer itself, particularly if it has a cotton-like structure, can also provide mechanical protection.

[0024] Such a diffusion layer can be designed as a three-dimensional spacer fabric, a diffusion film or multiple diffusion films, or a textile material, in particular made of transparent or semi-transparent plastic fibers, especially as a woven fabric of PMMA fibers (polymethyl methacrylate) with a mechanical surface treatment and / or polymer optical fibers (POF). POF are polymer-based optical fibers, using materials such as PMMA, polycarbonates, polystyrenes, silicones, polyethersulfones, polysulfones, or polyetherimides as the core material. A mechanical surface treatment, such as an abrasive treatment or the targeted introduction of defects, creates irregularities or defects in the surface through which light can enter and exit.Such a diffusion layer disperses the illumination light even more than is possible through the planar arrangement of the light sources on the circuit board and is particularly advantageous when the uniformity of illumination achieved without a diffusion layer is still insufficient, for example at a small distance to the illuminated objects or scenes.

[0025] The efficiency of the lighting is increased if the circuit board beneath the light source is provided with a reflective surface, in particular an aluminum layer. This can be a separate layer or a coating, for example, a complete or partial metal vapor deposition.

[0026] In embodiments specifically designed for weather resistance, the circuit carrier, including the light sources and electrical wiring, is coated with a waterproof coating, particularly silicone. Such a coating also protects against the ingress of dust and foreign matter, provides mechanical stress relief for the electronic components and wiring on the surface-mounted light fixture, and can also protect against short circuits. Suitable materials include, for example, air-curing silicones, water-repellent lacquers, membranes, laminations, or other water-repellent coatings.

[0027] In various embodiments, the control unit housing includes a circumferential seal at one or more openings, designed to prevent the ingress of moisture or liquids. Such a seal can be a neoprene seal and / or a silicone seal, which is sealed by pressing or screwing the housing halves together. This applies to all housing openings of the control unit housing. A neoprene seal is particularly suitable, for example, for sealing the opening through which the surface lighting element is inserted into the housing; however, other sealing materials such as silicone can also be used at this point.

[0028] Further applications arise when a stiffening frame is included, which is connected or connectable to the surface lighting fixture around its circumference or at two or more points. In its stiffened state, the frame supports the surface lighting fixture, while in its relaxed state, it allows the fixture to be folded and / or rolled up together with the stiffening frame. Such a lighting fixture does not necessarily require an external bracket or support surface, but can be used standing upright, as the flexible surface lighting fixture is supported in its stiffened state by the integrated frame. This also makes it possible to place the lighting unit on the floor without any additional aids.

[0029] Several concepts are suitable for implementing the stiffening frame. In some embodiments, the stiffening frame comprises an airtight or fluid-tight inflatable tube that can be filled and emptied with air or a fluid by means of an external pump or a pump integrated into the control unit housing. Such a tube is attached either circumferentially or at several points around the circumference of the surface lighting unit, thus defining its shape when inflated. It can also be integrated into the edge of the surface lighting unit.

[0030] In other embodiments, the stiffenable frame comprises one or more sections in which a spiral spring or a series of aligned tubes with internal tension wires is arranged, which are connected on one side to a tightening device and on the other side to an end of the spiral or the series of aligned tubes, which can be stiffened by tensile loading of the tension wires and can be made flexible by relieving the tension wires by means of a stiffening device arranged in the control unit.

[0031] In various embodiments, the stiffening frame has an O-shape, an X-shape, or a U-shape.

[0032] If the frame is located on the front of the surface lighting unit, its surface can be designed to be connected to additional layers, such as a removable diffusion layer and / or a directional grid. This can be achieved, for example, using a hook-and-loop fastener.

[0033] In further embodiments, the frame connected to the lighting device comprises a metallic material based on porous nanostructures, which is permeated with an ionic, voltage-responsive liquid. By applying an external voltage from the lighting device's control unit, this material can be reversibly stiffened into any desired shape. Such a material was disclosed, for example, in Hai-Jun Jin, Jörg Weissmüller, "A Material with Electrically Tunable Strength and Flow Stress", Science, Vol. 332, Issue 6034, pp. 1179-1182. Thus, the surface lighting element can, for instance, be unrolled while the frame material is soft. Once the surface lighting element has been brought into the desired shape, the frame is stiffened by applying the external voltage, so that the surface lighting element retains the shape it has assumed.

[0034] For transport, it is advantageous if the lighting unit is wound up and secured in the wound state. In some embodiments, the surface lighting unit has a fixing means for releasably securing one end of the surface lighting unit, opposite the control unit, to another location on the housing or the surface lighting unit itself. This fixing means secures the lighting unit in a state where it is wound around the control unit. Such a fixing means could be, for example, a snap fastener, a hook-and-loop fastener, or a magnet that interacts with a counterpart on the housing or on the underside of the surface lighting unit. Alternatively, a tension-stiffening technology could also be used.

[0035] For operation, the control unit in embodiments, particularly waterproof ones, comprises operating elements, in particular a membrane keypad, and / or a wireless communication interface, via which the control unit can be remotely operated by means of a remote control unit or a mobile terminal.

[0036] Further features of the invention will become apparent from the description of embodiments according to the invention, together with the claims and the accompanying drawings. Embodiments according to the invention may fulfill individual features or a combination of several features.

[0037] Within the scope of the invention, features marked with "in particular" or "preferably" are to be understood as optional features.

[0038] The invention is described below, without limiting the general concept, with reference to exemplary embodiments and the drawings, whereby for all details of the invention not explained in detail in the text, explicit reference is made to the drawings. The drawings show: Fig. 1 a schematic perspective drawing of an embodiment with strain relief, Fig. 2 a schematic perspective drawing of an embodiment from the outside, Fig. 3 a schematic cross-sectional drawing of an embodiment in the wound state, Fig. 4 a schematic representation of a layer structure of an embodiment, Fig. 5 a schematic detail drawing of another layer structure, Fig. 6 a schematic representation of the components of a control unit of an embodiment, Fig. 7 various configurations of integrated stiffening frames, Fig. 8 schematic representations of another embodiment with strain relief, Fig. 9 a schematic top view of the embodiment of Fig. 8 Fig. 10 schematic representations of a further embodiment with a strain relief, Fig. 11 a schematic top view of the embodiment of the Fig. 10and Fig. 12 a schematic cross-sectional representation of the embodiment of the Fig. 10 .

[0039] In the drawings, identical or similar elements and / or parts are provided with the same reference numbers, so that a re-presentation is omitted.

[0040] Fig. 1Figure 1 schematically illustrates a perspective view of an embodiment of a lighting unit 10 according to the invention. The lighting unit 10 comprises a control unit 20, the housing 22 of which is shown in its open state, without the electronic components such as circuit boards, batteries, circuits, control electronics, etc., arranged therein. The housing 22 has three tensile grips 24 on one transverse side, which project from a lower surface of the housing 22, and onto which a surface light source 50 is attached. For this purpose, the surface light source 50 has three eyelets 54 on one of its edges, i.e., reinforced openings that ensure a strain-relieved fit of the surface light source 50 onto the tensile grips 24 in the housing 22. The surface light source 50 is flexible and flat in design and has a light-active surface 56, which is surrounded by a non-light-active edge 52, or which does not need to be.

[0041] Instead of strain relief via the strain-receiving pins 24 and eyelets 54, a clamping device (not shown) can also be used, which grips and clamps the surface lighting body 50 along one of its edges 52, optionally with a rubberized or profiled surface. The clamping then takes place along the side that, in the exemplary embodiment of the Fig. 1 which has 54 eyelets.

[0042] In the exemplary embodiment in Fig. 2Figure 1 shows a perspective schematic external view of a lighting unit 10 according to the invention, in which the housing 22 of the control unit 20 is closed. The surface lighting element 50 protrudes from the housing 22 and has approximately the same width as the housing 22, although it may optionally be wider or narrower. Electrical conductors 60 and LED light sources 58 are shown by way of example in the illuminating area 56, which actually fill the entire illuminating area 56. It is indicated that the LEDs are each arranged on circuit boards 59, each of which is connected by two or more conductors 60 that serve to supply power. Several different LEDs with different colors or color temperatures can also be used on each circuit board, which are individually controlled to adjust the color temperature of the overall illumination. The invention is not limited to the selection of LEDs as light sources.

[0043] The LED light sources 58 and electrical conductors 60 are mounted on a circuit carrier 80, which may have a textile base, for example, a textile fabric. Details are described in DE 10 2014 206 882 B4. The electrical conductors and the circuit boards 59 can be sewn to the textile fabric, resulting in a secure yet low-stress connection between the electrical components and the circuit carrier 80. The design of the connection between the electrical components and the textile circuit carrier 80 creates a structure that can be easily and repeatedly rolled and folded.

[0044] The edge of the surface lighting unit 50 has a circumferential, stiffening frame 70 in an O-shape. This frame is an inflatable tube that is filled with compressed air or another pressurizable hydraulic fluid. Once the tube is filled with compressed air or hydraulic fluid and pressurized, it expands to its maximum dimensions, thus stabilizing the surface lighting unit 50. The tube can either be part of the surface lighting unit 50 or attached to it circumferentially, for example, with a hook-and-loop fastener. Once the compressed air or hydraulic fluid is released, the surface lighting unit 50, together with its stiffening frame 70, can be rolled up.

[0045] Fig. 3Figure 1 schematically shows a cross-sectional illustration of an embodiment of a lighting unit 10 according to the invention in its rolled-up state. The surface lighting element 50, with its integrated frame 70 and circuit carrier 80, is tightly wound around the housing 22 of the control unit 20 and secured at its end by means of a fixing element 65 so that it does not unwind on its own. In this initial example, the fixing element 65 is a snap fastener. However, it could also be a hook-and-loop fastener or a magnetic closure. In this state, the back of the surface lighting element 50 is turned outwards, optionally protected with a dirt- and rain-repellent material, so that the sensitive electrical and electronic components inside are protected against dirt and water.

[0046] Fig. 4Figure 1 represents a layered structure of an exemplary embodiment of a surface lighting element 50. LED light sources 58 are arranged on the textile circuit carrier 80, with a reflective layer 90 applied to the surfaces between the LED light sources 58. Alternatively, a mechanical protective layer can be used instead of the reflective layer 90, for example, in the form of a plastic film that has mask-like cutouts at the locations of the LED light sources 58, thus covering and electrically insulating the spaces between the LED light sources 58. This film can itself be metallized and thus constitute a reflective layer 90.

[0047] On the back of the circuit carrier 80 is a cooling layer 82, designed to absorb heat from the LED light sources 58 and conduct it into the surface and to the back, thereby reducing the temperature of the LED light sources 58 themselves compared to a configuration without a cooling layer 82. On the back of the cooling layer 82 is a rain- and dirt-repellent layer 84, made, for example, of a ripstop fabric. The rain- and dirt-repellent layer 84 can be attached to the cooling layer 82 or can be connected to the other layers only at their edges, so that an air cushion can form between the cooling layer 82 and the rain- and dirt-repellent layer 84.

[0048] On the front side, a diffusion layer 86 made of a diffusion fabric can be arranged, which is or will be connected to the circuit carrier 80 at the edge 52 of the surface lighting body 50.

[0049] Fig. 5Figure 1 shows a section from another initial example where the circuit carrier 80 and the LED light source 58 are encased together in a waterproof coating 88, for example, a silicone coating. The coating 88 does not need to have the same thickness across its entire surface, as shown, but can also be thinner in the area between adjacent LED light sources 58. This figure also shows a cross-section through an LED light source 58 with circuit boards 59 and electrical conductors 60, with the cross-sectional direction perpendicular to the longitudinal extent of the electrical conductors 60. The electrical conductors 60 can be sewn onto the circuit carrier 80, for example, if the carrier is a textile material. The two LEDs can have different color temperatures or colors. For example, one LED can produce a warm white, and the other a cool white.It may also include a third LED (not shown) that produces red light illumination, thus not disturbing the adaptation of the human eye to dark environments.

[0050] In Fig. 6 Figure 20 is a schematic example of the electrical and electronic components in the control unit. A central component is a control electronics unit 34, which is connected to a rechargeable or non-rechargeable battery 30 and may optionally include charging electronics for a rechargeable battery 30. Furthermore, the control electronics unit 34 is connected to the LED light sources 58 via the electrical lines 60 and controls them. A membrane keypad 32 is provided as an example of a manual input interface, which is used to communicate to the control electronics unit 34 how the LED light sources 58 should be controlled.

[0051] Optionally, an electric pump 38 can be provided, which, upon input and control by the control electronics 34, inflates a U-shaped surrounding frame 72 to stabilize the shape of the surface lighting unit 50. Furthermore, a wireless communication interface 36 can be provided, which receives signals from a remote control unit 40, decodes them, and transmits them to the control electronics 34. In this way, the operation of the lighting unit 10 can be remotely controlled.

[0052] Other possible components include buttons, display elements, especially LEDs or screens, which must also be integrated into the housing surface in a water- and dirt-resistant manner.

[0053] The Fig. 7Figure 1 shows three exemplary embodiments of different configurations of stiffening frames. The topmost image shows a circumferential O-shaped frame 70, which is connected to the edge of the surface lighting body 50 and supports it when inflated. The second image shows a very similar configuration with a U-shaped circumferential frame 72, which is similarly connected to the surface lighting body 50 along its edge and supports it when inflated. Additional cross braces may also be present, exerting outward pressure with respect to the long sides to further maintain the shape of the surface lighting body 50.

[0054] A third embodiment is shown in the lower part of the image. Fig. 7The figure shows the frame 74 having an X-shape. In this case, the frame is connected at its ends to the mounting points 76 of the surface lighting body 50 at its corners opposite the control unit 20, and its lateral stability is derived from the X-shape. The X-shaped frame 74 is to be arranged on the rear of the surface lighting body 50, while the O- and U-shaped frames 70, 72 can optionally be arranged on the front or the rear of the surface lighting body 50.

[0055] All three inflatable frames 70, 72, 74 can be deflated by releasing the compressed air or hydraulic fluid, in which the lighting unit 10 can be rolled up from the control unit 20.

[0056] As an alternative to the configuration of frames 70, 72, 74 as compressed air-fillable hoses, other embodiments are also possible. For example, the frames can also be filled with spirals through which a tension wire is guided. This wire is connected at one end to the end of a spiral and is connected to a tensioning device inside the housing 22 of the control unit 20. When the tensioning device is actuated, a tensile force is applied to the tension wire, forcing the spiral into a tightly fitting, inflexible configuration and thereby stabilizing it. Instead of a spiral, a series of cylindrical sections can also be used, through which a tension wire is guided accordingly. These sections center themselves on each other under tensile load and mutually support and stabilize one another.

[0057] The Figures 8 and 9Figure 1 schematically shows another embodiment of a lighting unit 10 with strain relief. In the upper illustration, the main circuit board 26 of the control unit 20 is not yet connected to the textile surface lighting element 50. The main circuit board 26 has a series of spring pins 25a at its edge, arranged between two spacers 27a with internal threads. The spring pins 25a can change their length because their tips are longitudinally axially movable and spring-loaded. This can be seen in Fig. 8 to identify where, in the unconnected state (above), the spring pins 25a have their full length and, in the assembled state (below), are retracted under the clamping load.

[0058] The surface lighting element 50 has a pre-circuit board 28 that rests flat on the textile substrate and is connected to it. The pre-circuit board 28 has through-holes for screws 27b, which are arranged such that, in the assembled state, the screws 27b engage in the internal threads of the spacers 27a. When the screws 27b are tightened, the pre-circuit board 28 is pressed onto the main circuit board 26. The pre-circuit board 28 has a series of contact surfaces 25b which, in the assembled state of the main and pre-circuit boards 26, 28, are opposite the spring pins 25a. They establish the electrical through-hole connection. The contact surfaces 25b are connected, for example by soldering, to the leads on the opposite side of the pre-circuit board 26, which lead to the light sources 58 and supply them with current.

[0059] The arrangement of the rows of spring pins 25a and contact surfaces 25b between the spacers 27a and screws 27b creates a very effective strain relief and contact 26. The mechanical loads are absorbed by the screws 27b and spacers 27a. The spring pin contact is flexible and allows a certain degree of twisting of the contact row without losing the electrical contact.

[0060] In Fig. 10 Another embodiment of a strain relief according to the invention is shown schematically. In comparison to the embodiment of the Figures 8 and 9The main change is in the type of contact. The surface lighting unit 50 is again equipped with a circuit board 28, which is connected on its underside to the electrical leads on the surface lighting unit 50. It has a pin header 29a with parallel contact pins. The main circuit board 26 has corresponding contact receptacles for receiving the contact pins of the pin header 29a. This is in Fig. 11 shown in more detail in a schematic top view.

[0061] This contact 29' is not mechanically stable on its own and would immediately separate again under tension. Therefore, as in Fig. 12 As shown in cross-section, a cover 100 or a frame is present, which receives the end of the surface body 50 in an opening and is screwed onto or to the housing 22. The mainboard 26 inside the housing 22 is in Fig. 12Not shown separately for the sake of clarity.

[0062] Behind the circuit board 28, the surface lighting element 50 is provided on at least one side, and in the illustrated embodiment on both sides, with stop strips 104, which may be sewn, glued, or otherwise attached. These prevent the surface lighting element 50 from being pulled out of the cover 100 or the frame. Together with the cover 100, they act as strain relief. The cover 100 can also be equipped with sealing lips made of rubber, silicone, or other suitable materials against which the stop strips 104 are pulled or pressed, thus reinforcing the sealing effect provided by the stop strips 104, particularly if they are designed as welt strips.

[0063] All features mentioned, including those discernible from the drawings alone as well as individual features disclosed in combination with other features, are considered essential to the invention, both individually and in combination. Inventive embodiments may be fulfilled by individual features or by a combination of several features. Reference symbol list

[0064] 10 Lighting unit 20 Control unit 22 Housing 24 Tension pin 25a Spring pin 25b Contact surface 26 Mainboard 27a Spacer with internal thread 27b Screw 28 Pre-board 29, 29' Contacting 29a Pin header 30 Battery 32 Membrane keypad 34 Control electronics 36 Wireless communication interface 38 Pump 40 Remote control unit 50 Surface light source 52 Edge 54 Eyelet 56 Light-active area 58 LED light source 59 Circuit board 60 Electrical wiring 65 Fixing element 70 O-shaped stiffening frame 72 U-shaped stiffening frame 74 X-shaped stiffening frame 76 Mounting points 80 Circuit carrier 82 Cooling layer 84 Rain and dirt repellent layer 86 Diffusion layer 88 Waterproof coating 90 Reflective layer 100 Cover 102 Attaching the cover to the housing 104 Stop strip

Claims

1. A lighting unit (10), comprising a flexible surface-lighting element (50), which has a plurality of illuminants (58) distributed over the surface of a planar carrier material, which carrier material comprises a flexible planar circuit carrier (80) which is in particular textile-based and which is fitted with the plurality of illuminants (58) on a front side, the illuminants being interconnected by electrical lines (60) configured in or on the circuit carrier (80), and a control unit (20) which is configured to supply power to and to control the plurality of illuminants (58), wherein the control unit (20) comprises a housing (22) which is arranged on an edge of the surface-lighting element (50) and is mechanically connected thereto, the edge of the surface-lighting element (50) being partly received in the housing (22) of the control unit (20), wherein the housing (20) comprises electrical and electronic components and lines which are connected to the electrical lines (60) of the surface-lighting element (50), and a strain relief means (24, 27a, 27b) which absorbs tensile stresses between the housing (22) of the control unit (20), on the one hand, and the surface-lighting element (50), on the other hand, and keeps said tensile stresses away from the electrical connections between the control unit (20) and the surface-lighting element (50), wherein the strain relief means (24, 27a, 27b) is configured to create a tension-resistant connection between the material of the surface-lighting element (50) and the housing (22), characterized in that the strain relief means (24, 27a, 27b) is configured as a clamping device, as a series of tension load-receiving pegs (24) which are guided through a series of eyelets (54) in the surface-lighting element (50) designed to match the arrangement of the tension load-receiving pegs (24), as spacers (27a) with internal threads and screws (27b) which are screwed or can be screwed into the internal threads of the spacers (27a), or as a cover (100) which is screwed or can be screwed or, respectively is clamped or can be clamped to or onto the housing (22).

2. The lighting unit (10) according to Claim 1, wherein the strain relief means is configured with a stop bar (104) attached to the surface-lighting element (50), which stop bar is configured to prevent the surface-lighting element (50) from being pulled out of the cover.

3. The lighting unit (10) according to Claim 1 or 2, wherein the carrier material is reinforced in the region of the eyelets (54) or the spacers (27a), in particular by a double layer of the flexible planar circuit carrier (80).

4. The lighting unit (10) according to any one of Claims 1 to 3, characterized in that electrical lines between the control unit (20) and the illuminants (58) are designed to be continuous or have an interruption with a contact arrangement, which are in particular arranged in the region of the strain relief means (24, 27a, 27b), wherein the contact arrangement is configured in particular as a spring-loaded pin contact with spring pins and opposing contact surfaces which are contacted and secured by fastening of the strain relief means, or as a pin header (29a) with contact pins which can be received or are received in corresponding contact pin receptacles.

5. The lighting unit (10) according to any one of Claims 1 to 4, characterized in that the surface-lighting element (50) has, on a rear side of the circuit carrier (80), a flexible planar cooling layer (82) which is mechanically or material-bonded to the circuit carrier (80), and / or a rain- and dirt-repellent layer (84), wherein in particular the cooling layer (82) is shielded externally by the rain- and dirt-repellent layer (84) or is configured as a rain- and dirt-repellent layer (84).

6. The lighting unit (10) according to any one of Claims 1 to 5, characterized in that the surface-lighting element (50) has, on a front side of the circuit carrier (80), a diffusion layer (86) which is in particular removable, and / or a directional grating.

7. The lighting unit (10) according to any one of Claims 1 to 6, characterized in that the circuit carrier (80) is equipped, below the illuminants (58), with a reflective surface, in particular an aluminum layer.

8. The lighting unit (10) according to any one of Claims 1 to 7, characterized in that the circuit carrier (80) with the illuminants (58) and the electrical lines (60) is coated with a waterproof coating (88), in particular silicone.

9. The lighting unit (10) according to any one of Claims 1 to 8, characterized in that the housing (22) of the control unit (20) comprises a circumferential seal at one or more openings which is or are configured to prevent the penetration of moisture or fluids.

10. The lighting unit (10) according to any one of Claims 1 to 9, characterized in that a stiffenable frame (70, 72, 74) is comprised, which is or can be circumferentially connected to the surface-lighting element (50) at the perimeter thereof or at two or more points (76), the frame (70, 72, 74) stretching the surface-lighting element (50) in the stiffened state and making it possible for the surface-lighting element (50) to be folded and / or rolled up together with the stiffenable frame (70, 72, 74) in the unstiffened state.

11. The lighting unit (10) according to Claim 10, characterized in that the stiffenable frame (70, 72, 74) comprises an air- or fluid-tight inflatable tube which can be filled with air or a fluid and which can be deflated again by means of an external pump (38) or a pump (38) integrated into the housing (22) of the control unit (20).

12. The lighting unit (10) according to Claim 10 or 11, characterized in that the stiffenable frame (70, 72, 74) comprises one or more sections in which a coil spring or a series of aligned tubes having internal tension wires is arranged, the tension wires being connected on one side to a tightening device and on the other side to one end of the coil or the series of aligned tubes, the arrangement being stiffenable by tensioning the tension wires and being transferable into a flexible state by relieving tension on the tension wires by means of a stiffening device arranged in the control unit (20).

13. The lighting unit (10) according to any one of Claims 10 to 12, characterized in that the stiffenable frame (70, 72, 74) has an O-shape, an X-shape or a U-shape.

14. The lighting unit (10) according to any one of Claims 1 to 13, characterized in that the surface-lighting element (50) has a fixing means (65) for detachably fixing an end of the surface-lighting element (50) opposite the control unit (20) to another point of the housing (22) or of the surface-lighting element (50), which fixing means fixes the lighting element (10) in a state in which the surface-lighting element (50) is wound around the control unit (20).

15. The lighting unit (10) according to any one of Claims 1 to 14, characterized in that the control unit (20) comprises operating elements which are in particular waterproof, in particular a membrane keypad (32), and / or a wireless communication interface (36) via which the control unit (20) can be operated remotely by means of a remote-control unit (40) or a mobile terminal.