Lighting unit with flexible surface lighting body and method for producing a lighting unit

Abstract

The invention relates to a lighting unit comprising a flexible surface lighting fixture and a control unit. The surface lighting fixture comprises a flat carrier material with a, in particular textile-based, flexible, flat circuit carrier, which is equipped on a front side with a plurality of lighting devices that are interconnected by electrical lines formed in or on the circuit carrier. The control unit comprises a housing arranged on an edge of the surface lighting fixture and mechanically connected to it. For connection to the control unit, the circuit carrier of the surface lighting fixture has at least one elongated flexible printed circuit board tongue with conductor tracks, which is guided into the control unit through a slot in a wall of the housing of the control unit.According to the invention, the housing comprises an inner wall on the inside of the slot, which defines a cavity with the wall of the housing having the slot, which cavity is open on one side towards an interior of the housing and forms a chicane through which the printed circuit board tongue is guided from outside the housing to inside the housing under at least one bend, in particular an S-shaped bend, wherein the cavity with the printed circuit board tongue guided through is filled with a sealing compound.

Description

[0001] The present invention relates to a lighting unit comprising a flexible surface lighting body and a control unit, as well as a method for producing such a lighting unit.

[0002] Corresponding area lighting fixtures are marketed by the applicant, among others, and are described in German patent DE 10 2014 206 882 B4. They are designed for various applications, for example, for wide-area illumination in photography, film, and television recordings. Continuous illumination with high luminosity is particularly required in the latter areas, which is usually achieved by systems consisting of spotlights, reflectors, and diffusers. To illuminate changing scenes, the lighting system components used must be flexible in their combination, placement, and alignment.

[0003] For this purpose, DE 10 2014 206 882 B4 proposes to provide a flexible surface lighting body which has a plurality of illuminants distributed over a surface on a flat carrier material, wherein a first layer is designed as a textile-based flexible flat circuit carrier which is equipped on a front side with the plurality of illuminants which are interconnected by electrical lines formed in or on the circuit carrier.

[0004] Such a surface lighting fixture is, in simple terms, a self-illuminating cloth that is bendable, rollable, foldable, rotatable, and crushable, and that has a luminosity distributed across its surface that is sufficient, for example, to illuminate a scene or part of a scene. Such "cloths" or flexible surface lighting fixtures can be manufactured in any size and are therefore easy to assemble. Because they correspond to conventional reflectors and diffusers in terms of their flexibility and surface area, they are suitable for replacing the familiar combinations of spotlights, reflectors, and diffusers. They also require a lower luminosity, as their luminosity is fully available to illuminate a given scene and is not, as with conventional spotlight systems, only partially deflected and diffused toward the scene.This also leads to a reduction in the waste heat generated.

[0005] German patent application DE 10 2020 116 917 A1 addresses the problem of such a lighting unit that the connection between the control unit and the panel lighting fixture is subjected to mechanical stress during use, which negatively impacts the electrical connection between the panel lighting fixture and the control unit. To remedy this problem, it is proposed to provide the part of the control unit housing in which an edge of the panel lighting fixture is accommodated with a strain relief device that absorbs tensile stresses between the control unit housing on the one hand and the panel lighting fixture on the other, and keeps them away from the electrical connections between the control unit and the panel lighting fixture.This makes the lighting unit mechanically very resilient and suitable for use, for example, in the illumination of tents, including makeshift tents in the military sector, in disaster control or in mobile medical facilities, in police operations for illuminating accident scenes, as well as for private use, as well as for photographers who need mobile, wide-area lighting outside of their studios that can be set up quickly.

[0006] Based on this prior art, it is an object of the present invention to design corresponding lighting units even more robust against external stresses.

[0007] This object is achieved by a lighting unit comprising a flexible surface lighting body and a control unit, wherein the surface lighting body comprises a flat carrier material with a, in particular textile-based, flexible, flat circuit carrier, which is equipped on a front side with a plurality of lighting means that are connected by electrical lines formed in or on the circuit carrier, wherein the control unit is designed to supply power to and control the plurality of lighting means and comprises a housing arranged on an edge of the surface lighting body and mechanically connected thereto, with electrical and / or electronic components and lines, wherein the circuit carrier of the surface lighting body has at least one elongated flexible printed circuit board tongue with conductor tracks for connection to the control unit,which is guided into the control unit through a slot in a wall of the housing of the control unit, wherein the lighting unit is further developed in that the housing comprises an inner wall on the inside of the slot, which, together with the wall of the housing having the slot, defines a cavity which is open on one side towards an interior of the housing and forms a chicane through which the printed circuit board tongue is guided from outside the housing to inside the housing under at least one bend, in particular an S-shaped bend, wherein the cavity with the printed circuit board tongue guided through is filled with a sealing compound.

[0008] In this way, the interior of the control unit housing is hermetically sealed and protected against the ingress of dust and moisture.

[0009] The flexible panel light advantageously has textile components and LED-carrying PCB carriers (PCBs, printed circuit boards) that are bonded to the embroidered conductor tracks on the textile. To protect against environmental influences such as dust, but especially moisture, the panel light can be fully laminated. The laminate can consist of several layers and wrap around the panel light like a sandwich. A water vapor barrier can be implemented on the very outside, i.e., on the light-emitting side and the side facing away from the light. A thermoplastic can be placed underneath, above and below the light body, and the light body itself can be placed in the center. Both the vapor barrier and the thermoplastic can advantageously be very thin, for example, approximately 50 µm thick, transparent films. These films preferably do not shift the color space, do not generate heat build-up, and are UV-stable, water vapor-tight, elastic, and can withstand high mechanical stress.

[0010] The laminate can be created, for example, through a thermal process under pressure at approximately 140°C, depending on the material chosen. The material should be selected so that the LED assemblies of the panel light are not exposed to excessive heat. The laminate preserves the textile characteristics of the panel light. The vapor barrier can be an aliphatic polyurethane, for example. The flexible circuit board tongue is laminated to the extent that the laminated part still extends into the control unit housing.

[0011] The housing can advantageously be made of solid aluminum, which can be anodized after milling for aesthetic reasons. This anodizing effect should be considered when selecting the potting compound. The potting compound, which is filled into the designated cavities inside the housing, should also provide a watertight seal between the transitions from the flexible circuit boards to the interior of the housing and the housing slots. An example of this is Sikaflex ®< , a 1-component product with a relatively high viscosity. It is a PU-based sealant; it is stable, tear-resistant, cures in atmospheric moisture, is easy to apply and bubble-free, allows for precise processing, and, above all, adheres firmly to all materials suitable for the application (laminate, flexible circuit boards, anodized aluminum housing).

[0012] Alternatively, the control unit housing can also be made of other metals such as stainless steel or titanium, or from carbon fiber composites. Aluminum, on the other hand, has the advantage of being lighter than stainless steel, cheaper to procure than titanium, and better and easier to process than carbon fiber.

[0013] In the context of the present disclosure, a printed circuit board tab is understood to be an elongated, narrow piece of a flexible printed circuit board on which one or more conductor tracks are arranged parallel to one another to enable a connection to electrical or electronic supply and / or control elements. The conductor tracks can, for example, terminate at the end of the printed circuit board tab in soldering areas, so-called solder pads, onto which the contacts of the supplying electrical or electronic components are soldered. Alternatively, the ends of the flexible conductor tracks can, for example, lead to a ZIF connector (zero insertion force connector), which is located as a component in the housing on a mainboard. This has the advantage in the process that contacting is faster and more reliable.The ZIF connector is opened, the contact surface of the flexible circuit board is inserted, and closing the ZIF connector clamps the end, ensuring electrical contact. This type of contact is reversible, secure, and fast, but must be protected from mechanical stress and tensile forces.

[0014] Sealing cavities into which flexible printed circuit boards are inserted through a slot in the cavity wall is notoriously difficult. DE 10 2020 116 917 A1 proposes a circumferential seal in the form of a neoprene seal and / or a silicone seal, which is sealed by pressing or screwing the housing halves together. However, such pressed or screwed seals leave small gaps at the edges of the objects being inserted, such as a flat flexible printed circuit board, through which moisture can still enter the interior of the housing, for example, through capillary forces.

[0015] Sealing by encapsulation offers greater tightness here, as the flexible circuit board is completely embedded and enclosed, and no capillaries remain open, as is the case with a pressed or screwed circumferential neoprene or silicone seal. Instead, as the sealant hardens, a material-to-material bond forms between the sealant and the surface of the circuit board tongue. However, such a seal is mechanically vulnerable to tensile stress on the circuit board tongue, especially with flat objects such as the narrow and flat circuit board tongue. The tongue can be released from the surrounding sealant and pulled out slightly with little force. Once the material-to-material bond between the surface of the circuit board tongue and the surrounding sealant has been broken, a connection channel has formed around the circuit board tongue, through which moisture, for example, can penetrate due to capillary forces.

[0016] For this reason, the PCB tongue is embedded within the sealing compound with a bend. The particularly S-shaped bend of the PCB tongue ensures that tensile stress from outside the housing on the PCB tongue is not only transferred to the surrounding sealing compound via the material bond, but is also absorbed by pressure directly on the sealing compound on the side of the bend facing away from the tensile direction. At this point, the shear forces that would cause the material bond between the sealing compound and the PCB tongue to detach are lower or non-existent. In this way, the curved course of the PCB tongue through the sealing compound offers a certain degree of strain relief, which also provides resilience against detachment of the material bond between the sealing compound and the PCB tongue.

[0017] In the section of the PCB tongue surrounded by sealant, the PCB tongue can undergo one or more bends, for example, in an S-shape or in the form of a wave. A deflection angle of a bend of 30° or more is preferred, but deflection angles of 90° or more are also possible. The deflection angle indicates by how many degrees the further course of the PCB tongue is deflected compared to a straight line. A deflection angle of 0° would indicate no deflection or bend at all.

[0018] The bending of the PCB tongue in the sealant is forced by the cavity acting as a baffle, which is formed by an inner wall directly behind the slot and which is open towards the interior of the housing in a direction transverse to the direction in which the PCB tongue is inserted through the slot into the housing. Thus, after passing straight through the slot, the PCB tongue first encounters the inner wall that defines the baffle cavity and must be bent in order to be guided around the inner wall. The cavity can also be filled with sealant through the same opening to the interior of the housing through which the PCB tongue exits the cavity. The cavity has the further effect of providing a well-defined volume for filling with sealant, so that the remaining interior of the housing is protected from the sealant.

[0019] Preferably, in the final state, the circuit board tongue has no contact with the wall of the control unit housing, but is completely surrounded by sealing compound in the area of ​​the cavity forming the baffle.

[0020] Rubber, silicone, or a plastic can be used as the sealant. Various PU compounds are preferred. Based on their chemical properties, two-component materials are well suited, as are two-phase processes, in which all micro-cavities are filled or lined with a low-viscosity sealant, and then the larger volume of the respective cavity is filled with a higher-viscosity sealant.

[0021] The processing time depends on the selected materials and can be up to one hour, allowing the sealant to set slowly. The commercially available Sikaflex®, for example, is well-suited and meets the physical requirements of the product and its individual material components, while being easy to handle. Its viscosity is approximately 20 mm² / s at 40 °C.

[0022] In one embodiment, the edge of the panel lighting fixture is accommodated in sections within the control unit housing, wherein the housing comprises a strain relief means that absorbs tensile stresses between the control unit housing on the one hand and the panel lighting fixture on the other hand and keeps them away from the passage of the printed circuit board tongue through the baffle, in particular from the electrical connections between the control unit and the panel lighting fixture. The strain relief means acts externally from the passage of the printed circuit board tongue through the slot into the housing, thus relieving both the hermetic feedthrough and the electrical contacting inside the control unit housing.

[0023] In some embodiments, the strain relief means is designed as a clamping device or as a row of two or more tension-receiving pins, which are guided through a row of eyelets in the panel lighting fixture designed to match the arrangement of the tension-receiving pins. In particular, the carrier material is reinforced in the area of ​​the eyelets, in particular by a double layer of the flexible, flat circuit carrier. This can be a stable textile outer component, for example, a ripstop and / or a hem binding tape. A previously described laminate preferably ends internally in front of this area in the textile of the panel lighting fixture, thus not being punched, thus ensuring watertightness.In one embodiment, the eyelets can be designed as lock washers or comprise lock washers or be secured by lock washers that prevent slipping back after being pushed onto the tension receiving pin. In the context of the present disclosure, rings with a star-shaped central opening are referred to as lock washers. Such lock washers, also called spring washers, spring rings, star rims or toothed washers, have essentially triangular, bendable surfaces or inward-facing teeth pointing inward from the edge. If such a lock washer is pushed onto a tension receiving pin whose diameter is slightly larger than the innermost diameter of the lock washer, the inward-facing teeth are bent upward and act as barbs to prevent the lock washer from being pushed back.Such a connection can hardly be removed without causing damage and therefore offers a high level of mechanical security against unintentional loosening.

[0024] In some cases, the control unit housing is assembled from two or more parts. To ensure water and moisture resistance, some embodiments provide for two or more parts of the control unit housing to be sealed against each other using a sealant applied along their abutting edges. This sealant can be the same sealant used in the cavities forming the baffles or other known sealants suitable for watertight sealing of abutting edges. Additionally, the housing parts can be screwed together.

[0025] In embodiments, the surface lighting fixture has a flexible, flat cooling layer on a rear side of the circuit carrier, which is mechanically or materially connected to the circuit carrier, and / or a rain and dirt-repellent layer, wherein in particular the cooling layer is shielded from the outside by the rain and dirt-repellent layer or is designed as a rain and dirt-repellent layer, and / or a, in particular removable, diffusion layer and / or a directional grid on a front side of the circuit carrier and / or the circuit carrier is provided with a reflective surface, in particular an aluminum layer, below the illuminants. These various layers, of which one, several, or all may be present, serve to protect against environmental influences and to distribute the light. However, the diffusion layer does not have to be removable.It can also be firmly connected to individual or all other textile components by a seam.

[0026] In embodiments, the circuit carrier with the lighting means and the electrical lines is coated with a waterproof coating, in particular silicone, a lacquer or a laminate, wherein the waterproof coating also covers in particular the flexible printed circuit board tongue at least up to the housing of the control unit.

[0027] In further embodiments, the control unit comprises, in particular waterproof, operating elements, in particular a membrane keypad, and / or a wireless communication interface via which the control unit can be remotely controlled using a remote control unit or a mobile device. Membrane keypads are waterproof and suitable for use under demanding environmental conditions.

[0028] In one embodiment, the membrane keypad has an elongated, flexible printed circuit board tongue with conductor tracks for electronic connection to electrical or electronic components in the housing. The tongue is guided into the housing through a further slot in a wall of the housing and a cavity filled with a sealing compound, which forms a baffle for the printed circuit board tongue. The membrane keypad can thus be mounted or attached externally to the housing, with the electrical connection of the membrane keypad to the control electronics being implemented and hermetically sealed inside the housing of the control unit in the same or similar manner as that of the panel lighting unit.

[0029] In a further embodiment, an opening with a pressure membrane is provided in a wall of the control unit housing, which is connected to an edge of the opening in a watertight manner, wherein the pressure membrane is designed in particular for a water column of up to 2 m. The pressure membrane extends the functionality of the lighting unit beyond watertightness to applications at high altitudes, such as in aircraft or underwater. For this purpose, a concentric hole can be provided in the wall of the housing tray, for example with a diameter of approximately 1 mm, with a relief in the housing wall of a further approximately 1 mm all around, for example at the point where the slot for the flexible circuit board of the area lighting unit is located. Here, for example, a pressure membrane that meets the desired target criteria can be applied using self-adhesive tape from the outside of the housing.The adhesive preferably has the appropriate water resistance rating. This allows pressure to be equalized while maintaining the watertightness of all compartments of the control unit.

[0030] The object underlying the invention is also achieved by a method for producing a lighting unit with a flexible surface lighting body and a control unit, in particular a previously described lighting unit according to the present invention, with the following steps: Arranging the flexible surface lighting body on the edge of a housing of the control unit, threading an elongated flexible printed circuit board tongue of the flexible surface lighting body through a slot in a wall of the housing of the control unit and a cavity forming a baffle, which is defined by an inner wall with the wall of the housing having the slot, and producing a hermetic seal by filling the cavity forming the baffle, including the threaded printed circuit board tongue, with a sealing compound.

[0031] The method, using the means described above, creates a hermetic and resistant passage of the printed circuit board tongue into the housing of the control unit and thus realizes the same features, properties and advantages as the lighting unit according to the invention.

[0032] In one embodiment of the method, after threading and before or after creating the hermetic seal, an electrical connection is established between one or more contact surfaces on the circuit board tongue and one or more electrical or electronic components in the housing of the control unit.

[0033] In embodiments, the flexible surface lighting body is connected to the housing after arrangement and before or after threading and before or after producing a hermetic seal, wherein in particular a strain relief of the passage of the circuit board tongue through the hermetic seal is realized.

[0034] In further embodiments, an operating element, in particular a membrane keyboard, is attached to the housing of the control unit, wherein an elongated flexible printed circuit board tongue of the operating element is threaded into the housing through a slot and a cavity arranged directly inward of the slot and designed as a chicane, and the feedthrough is then hermetically sealed by encapsulating the cavity forming the chicane with a sealing compound.

[0035] In embodiments, some or all of the aforementioned method steps are performed with an at least partially open control unit housing, which is closed after completion of the hermetic connection or connections. In such cases, two or more parts of the housing can preferably be sealed against one another before closing by means of a sealing compound applied along their abutting edges. In this way, the watertightness is extended to all abutting edges of the housing parts. The sealing compound can be the same one used for the cavities forming the baffles, or a different sealing compound suitable for sealing abutting edges.

[0036] Further features of the invention will become apparent from the description of embodiments of the invention together with the claims and the accompanying drawings. Embodiments of 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 inventive concept, using exemplary embodiments with reference to the drawings, whereby express reference is made to the drawings for all details of the invention not explained in more detail in the text. They show: Fig. 1 is a schematic perspective basic representation of a lighting unit, Fig. 2 is a schematic perspective basic representation of a lighting unit from the outside, Fig. 3 is a schematic cross-sectional representation of a lighting unit in the wrapped state, Fig. 4 is a schematic representation of a layer structure of a surface lighting body, Fig. 5 is a schematic detailed representation of a further layer structure, Fig. 6 is a schematic representation of the components of a control unit of a lighting unit, Fig. 7 is a schematic exploded view of an embodiment of a lighting unit, Fig. 8 is a schematic representation of an embodiment of a control unit with sectional views, Fig. 9 is a schematic perspective view of the control unit and Fig. 10 is a further schematic perspective view of the control unit.

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

[0040] Fig. 1shows a lighting unit 10 schematically in perspective, as known from the applicant's German patent application DE 10 2020 116 917 A1. The lighting unit 10 comprises a control unit 20, the housing 22 of which is shown in the open state and without the electronic components arranged therein, such as circuit boards, batteries, circuits, control electronics, etc. The housing 22 has three tension receiving pins 24 on one transverse side, which protrude from a lower surface of the housing 22 and onto which a surface lighting element 50 is plugged, which for this purpose has three eyelets 54 on one of its edges, i.e. reinforced openings that ensure a strain-relieved fit of the surface lighting element 50 on the tension receiving pin 24 in the housing 22. The surface lighting body 50 is flexible and flat and has a luminous surface 56 which is surrounded by an edge 52 which is not luminous or does not have to be luminous.

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

[0042] At the Fig. 2In the illustrated lighting unit, also known from DE 10 2020 116 917 A1, the housing 22 of the control unit 20 is closed. The surface lighting body 50, which has approximately the same width as the housing 22 and can optionally also be wider or narrower, emerges from the housing 22. In the luminous-active area 56, electrical lines 60 and LED lamps 58 are shown as examples, which actually fill the entire luminous-active area 56. It is indicated that the LEDs are each arranged on circuit boards 59, which are each connected by means of two or more lines 60 that serve to supply power. Several different LEDs with different colors or color temperatures can also be used per circuit board, which are individually controlled in order to adjust the color temperature of the overall lighting. Embodiments are not limited to the selection of LEDs as light sources.

[0043] The LED lamps 58 and electrical lines 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 lines and circuit boards 59 may be sewn to the textile fabric, resulting in a simultaneously secure and low-stress connection between the electrical components and the circuit carrier 80. The nature of the connection between the electrical components and the textile circuit carrier 80 results in a structure that can be easily and repeatedly rolled and folded.

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

[0045] Fig. 3shows a schematic cross-sectional view of an embodiment of a corresponding lighting unit 10 in a rolled-up state. The surface lighting body 50 with the integrated frame 70 and the 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 means 65 so that it cannot unwind itself. In this example, the fixing means 65 is a snap fastener. However, it can also be a hook-and-loop fastener or a magnetic closure. In this state, the rear side of the surface lighting body 50 is facing outwards and is 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. 4depicts a layer structure of an exemplary surface lighting fixture 50 according to DE 10 2020 116 917 A1. LED illuminants 58 are arranged on the textile circuit carrier 80, with a reflective layer 90 applied to the surfaces between the LED illuminants 58. Alternatively, instead of the reflective layer 90, a mechanical protective layer can be used, for example in the form of a plastic film that has mask-like recesses at the locations of the LED illuminants 58 and thus covers and electrically insulates the spaces between the LED illuminants 58. This film itself can also be metal-deposited and thus represent a reflective layer 90.

[0047] On the back of the circuit carrier 80 is a cooling layer 82, which is designed to absorb heat from the LED lamps 58 and conduct it into the surface and to the back, thereby lowering the temperature of the LED lamps 58 themselves compared to a configuration that does not have a cooling layer 82. A rain and dirt-repellent layer 84, made of a ripstop fabric, for example, is arranged on the back of the cooling layer 82. The rain and dirt-repellent layer 84 can be attached to the cooling layer 82, but can also be connected to the other layers only at the edges, so that an air cushion can be formed between the cooling layer 82 and the rain and dirt-repellent layer 84. A diffusion layer 86 made of a diffusion fabric can be arranged on the front, which is or will be connected to the circuit carrier 80 at the edge 52 of the surface lighting body 50.

[0048] Fig. 5shows a section of a further example according to DE 10 2020 116 917 A1, in which the circuit carrier 80 with the LED light source 58 is enclosed in a waterproof coating 88, for example a silicone coating. The coating 88 does not have to have the same thickness over the entire surface, as shown, but can also be thinner than shown in the area between adjacent LED light sources 58. This illustration also shows a cross-section through an LED light source 58 with circuit boards 59 and electrical lines 60, wherein the cross-sectional direction runs transversely to the longitudinal extent of the electrical lines 60. The electrical lines 60 can be sewn onto the circuit carrier 80, for example, if the carrier is a textile. The two LEDs can have different color temperatures or colors. For example, one LED can produce a warm white, the other a cool white.It may also include a third LED (not shown) that produces red light illumination, which does not disturb the adaptation of the human eye to dark environments.

[0049] In Fig. 6 An example according to DE 10 2020 116 917 A1 for the electrical and electronic components in the control unit 20 is shown schematically. The central component is a control electronics unit 34, which is connected to a rechargeable or non-rechargeable battery 30 and optionally includes charging electronics for a rechargeable battery 30. Furthermore, the control electronics unit 34 is connected to the LED lamps 58 via the electrical lines 60 and controls them. A membrane keyboard 32 is provided as an example of a manual input interface, which is used to inform the control electronics unit 34 how the LED lamps 58 are to be controlled.

[0050] Optionally, an electric pump 38 may 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 area lighting fixture 50. Furthermore, a wireless communication interface 36 may be provided, which receives signals from a remote control unit 40, decodes them, and forwards them to the control electronics 34. In this way, the operation of the lighting unit 10 can be remotely controlled.

[0051] Other possible components are buttons, display elements, especially LEDs or screens, which must also be integrated into the housing surface in a water- and dirt-tight manner.

[0052] Fig. 7shows a schematic exploded view of a lighting unit 10 according to the invention. The only schematically illustrated area lighting body 50 is connected on one narrow side via a flexible circuit board tongue 57 to control and power electronics 34 of a control unit 20, the components of which are arranged on a circuit board 35. Above and below the circuit board 35, a lower housing part of the housing 22 and a housing cover 23 are shown, which, when assembled, form the housing 22 of the control unit 20. The abutting edges between the housing 22 and the housing cover 23 can be made watertight using a sealing compound. The housing 22 has a compartment for a battery 30 or a rechargeable battery, as well as a membrane keyboard 32 on its top side.The battery compartment is located externally of the interior of the housing 22 and has its own sealing means, not shown, for example one or two terminal screw plates which are or are screwed together with sealing rings into a suitable internal thread at the end of the battery compartment.

[0053] Also shown is a locking washer 28 in the form of a toothed washer or spring washer or star eyelet, which is pushed onto a tension receiving pin 24 (not shown) on the inside of the upper half of the housing 22, which is guided through one of the eyelets 54 in the area lighting body. Fig. 7 the tension receiving pin 24 is covered by the wall of the housing 22, in the sectional view of the Fig. 8 but visible.

[0054] The contacting of the electrical connecting lines of the surface lighting body 50 with the corresponding contacts on the printed circuit board 35 can be done in various ways, for example as described in DE 10 2020 116 917 A1, the disclosure content of which is intended to be incorporated in its entirety.

[0055] In addition to a conventional soldered connection, the surface lighting element 50 can alternatively be equipped, for example, with a pre-circuit board 28, which is connected on its underside to the electrical lines on the surface lighting element 50 and has a pin strip with contact pins aligned parallel to one another. In such a case, the main circuit board 26 has corresponding contact receptacles for receiving the contact pins of the pin strip. Such a contact alone is not mechanically stable and would immediately separate under tension. Therefore, in such a case, a cover or frame is preferably provided, which receives the end of the surface element 50 in an opening and is or is screwed onto or to the housing 22.

[0056] Behind the front plate, the surface lighting fixture 50 can be provided on at least one side with stop strips, which can be sewn, glued, or similarly attached. These prevent the surface lighting fixture 50 from being pulled out of the cover or frame. Together with the cover, they act as strain relief devices. The cover can also be equipped with sealing lips made of rubber, silicone, or other suitable materials, against which the stop strips are pulled or pressed, reinforcing the sealing effect provided by the stop strips, especially when they are designed as piping strips.

[0057] In Fig. 8 the housing 22 of a control unit 20 according to the invention is shown schematically, as well as two sectional views along section planes AA and BB, which are identified in the central view.

[0058] The housing 22 encloses an interior space 31 in which control electronics 34 are arranged, which for reasons of clarity are shown in Fig. 8not shown. On one side, shown here at the top, the housing 22 encloses a lateral receptacle 25, which serves to accommodate one side of a surface lighting fixture 50. This lateral receptacle 25 is separated from the interior 31 of the housing by a side wall of the housing 22. In this lateral receptacle 25, tension receiving pins 24 are arranged as part of the housing 22 or firmly connected to the housing 22, onto which the eyelets 54 of the surface lighting fixture 50 are pushed. The surface lighting fixture 50 is then secured to the tension receiving pin 24 with locking washers 28. The connection to the tension receiving pins 24 ensures that tensile loads of the surface lighting fixture 50 are transferred primarily to the housing 22 of the control unit 20, but not to the electrical connection to the control electronics.

[0059] For the electrical connection of the LEDs or other lighting devices of the panel lighting unit 50 to the control electronics 34, the panel lighting unit 50 has a flexible printed circuit board 55 on the side that connects to the housing 22. The flexible printed circuit board 55 has soldering points or other connecting means to which the lines leading to the lighting devices are connected. The flexible printed circuit board 55 comprises or is connected to a flexible printed circuit board tongue 57, which has electrical conductor tracks that terminate in connection points, for example, soldering points, at the end of the printed circuit board tongue 57. This printed circuit board tongue 57 must be inserted from the outside into the interior 57.

[0060] In order to make this feedthrough both hermetic and stress-resistant, it has several components. First, the circuit board tongue 57 is guided through a narrow slot 26 in the side wall that defines the interior space 31 of the housing 22. There, however, the circuit board tongue 57 does not enter the interior space 31 directly, but first into a cavity 27 formed by the side wall of the housing 22 and an inner wall 27' directly behind the slot 26. The inner wall 27' obstructs the circuit board tongue 57, so it must be bent in order to be guided around the inner wall 27'. The cavity 27 is open towards the interior space 31 in the direction of the bend of the circuit board tongue 57 and forms the shape of a trough, which is particularly well suited for being filled with a sealing compound in a controlled manner. The geometry of this chicane formed by the inner wall 27' is clearly visible in section AA.In this example, the circuit board tongue 57 makes two 90° bends to pass through the slot 26 into the interior space 31.

[0061] After the circuit board tongue 57 has been inserted, the cavity 27 can be filled with a hardening sealing compound, which fills the cavity 27 completely or at least to the extent that a hermetic seal is created for the slot 26. At the same time, the sealing compound encloses the circuit board tongue 57 precisely in the bent part, so that tensile loads from the outside are diverted into the sealing compound and thus into the housing 22, rather than to the electrical contact between the circuit board tongue 57 and a circuit board 35 of the control electronics. Furthermore, this sealing geometry also protects the circuit board tongue 57 from being pulled out of the sealing compound.

[0062] In addition to the cavity 27, a second, smaller cavity (without reference symbol) is provided, which can be used in a similar manner for the passage of another, narrower printed circuit board tongue, which can be used, for example, for another membrane keyboard.

[0063] In the lower part of the Fig. 8 and section BB shows that a printed circuit board tongue 33 of a Fig. 8 not shown membrane keyboard 32 is guided in a similar manner through a baffle to be filled with a sealing compound, which is formed by a trough-shaped cavity 29 which is delimited by the outer wall of the housing and an inner wall 29' and is open on one side towards the interior 31 of the housing 22 of the control unit 20. This cavity 29 forms a baffle for the circuit board tongue 33 and can also be filled with a sealing compound in order to hermetically seal a corresponding slot for the circuit board tongue 33.

[0064] In the corners of the interior space 31 of the housing 22, there are also raised portions from the base plate to accommodate the ends of screws that are threaded through the housing tray. This places the screws physically outside the housing tray, maintaining the hermetic seal to the outside.

[0065] The Figures 9 and 10 show different perspective views of the housing 22 from Fig. 8 , which, among other things, corresponds to slot 26 ( Fig. 9 ) and the geometry of the trough-shaped cavity 27 ( Fig. 10 ). While in Fig. 9 the printed circuit board tabs 33, 57 are omitted, they are in Fig. 10 Also shown in Fig. 9 The lateral receptacle 25 can be seen particularly well, which is separated from the interior 31 of the housing 22 of the control unit 20 by a wall, with the exception of the slot 26, which is sealed in the manner described by filling the cavity 27.

[0066] A further detail that increases the application possibilities of the lighting unit 10 is an opening 37 in the side wall facing the receptacle for the surface lighting body 50, which Fig. 9 from outside and in Fig. 10 visible from inside the housing 22. This opening 37 accommodates a pressure diaphragm designed to compensate for varying external pressures. This can range from lower pressure at high altitudes, such as in the mountains or in an airplane, to higher pressure underwater. The pressure diaphragm can be designed, for example, for a water column, i.e., diving depth, of 2 m.

[0067] The opening 37 has a larger diameter from the outside than from the inside of the housing 22 and therefore has an annular recessed area on its outside into which a round pressure membrane can be attached with a waterproof adhesive, which has the required protection class for watertightness.

[0068] Additionally, a frame stiffening system may be provided for the flexible surface lighting body 50 not shown in Figures 8 to 10. Such a system may, for example, be provided with an inflatable tube, as shown in Fig. 2shown, which runs in an O-shape, U-shape and / or X-shape on the area lighting body. Alternatively, stiffening can also be achieved by means of foldable stiffening struts. Examples of such stiffeners are described in the patent application DE 10 2020 116 917 A1. In such cases, the frame structures are advantageously located outside the hermetic space of the housing 22 of the control unit 20. A stop for stiffening struts could, for example, be arranged or fixed on a protruding part of the housing 22 or the housing cover 23, or a blower unit for inflating a hose-based stiffener so that the interior 31 of the control unit 20 remains watertight.

[0069] All mentioned features, including those that can be inferred 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. Embodiments according to the invention may be fulfilled by individual features or a combination of several features. List of reference symbols

[0070] 10 Lighting unit 20 Control unit 22 Housing 23 Housing cover 24 Tension pin 25 Side mount 26 Slot 27 Cavity 27 Inner wall 28 Locking washer 29 Cavity 29 Inner wall 30 Battery 31 Interior 32 Membrane keypad 33 Flexible circuit board tongue 34 Control electronics 35 Circuit board 36 Wireless communication interface 37 Opening for pressure membrane 38 Pump 40 Remote control unit 50 Surface lighting unit 52 Edge 54 Eyelet 55 Flexible circuit board 56 Luminous surface 57 Flexible circuit board tongue 58 LED lamp 59 Circuit board 60 Electrical cables 65 Fixing means 70 Rigid frame in O-shape 72 Rigid frame in U-shape 76Mounting points 80Circuit carrier 82Cooling layer 84Rain and dirt-repellent layer 86Diffusion layer 88Waterproof coating 90Reflective layer

Claims

1. A lighting unit (10) comprising a flexible surface lighting body (50) and a control unit (20), wherein the surface lighting body (50) comprises a flat carrier material with a, in particular textile-based, flexible, flat circuit carrier (80), which is equipped on a front side with a plurality of lighting means (58) that are interconnected by electrical lines (60) formed in or on the circuit carrier (80), wherein the control unit (20) is designed to supply power to and control the plurality of lighting means (58) and comprises a housing (22) arranged on an edge of the surface lighting body (50) and mechanically connected thereto, said housing having electrical and / or electronic components and lines, wherein the circuit carrier (80) of the surface lighting body (50) has at least one elongated flexible printed circuit board tongue (57) with conductor tracks for connection to the control unit (20),which is guided into the control unit (20) through a slot (26) in a wall of the housing (22) of the control unit (20), , characterized in that the housing (22) comprises, on the inside of the slot (26), an inner wall (27') which, together with the wall of the housing (22) having the slot (26), defines a cavity (27) which is open on one side towards an interior space (31) of the housing (22) and forms a chicane through which the printed circuit board tongue (57) is guided from outside the housing (22) to inside the housing (22) under at least one bend, in particular an S-shaped bend, wherein the cavity (27) with the printed circuit board tongue (57) guided through is filled with a sealing compound.

2. Lighting unit (10) according to claim 1, characterized in thatthe edge of the surface lighting element (50) is accommodated in sections in the housing (22) of the control unit (20), wherein the housing (20) comprises a strain relief means (24) 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 them away from the passage of the printed circuit board tongue (57) through the baffle, in particular from the electrical connections between the control unit (20) and the surface lighting element (50).

3. Lighting unit (10) according to claim 1 or 2, characterized in thatthe strain relief means (24) is designed as a clamping device or as a row of two or more tension receiving pins (24) which are guided through a row of eyelets (54) in the surface lighting body (50) designed to match the arrangement of the tension receiving pins (24), wherein in particular the carrier material is reinforced in the region of the eyelets (54), in particular by a double layer of the flexible flat circuit carrier (80).

4. Lighting unit (10) according to claim 3, characterized in that the eyelets (54) are designed as locking washers (24) or comprise locking washers (24) or are secured by locking washers (24) which prevent slipping back after being pushed onto the tension receiving pins (24).

5. Lighting unit (10) according to one of claims 1 to 4, characterized in thattwo or more parts of the housing (22) of the control unit are sealed against each other in a watertight manner by means of a sealing compound applied along their abutting edges.

6. Lighting unit (10) according to one of claims 1 to 5, characterized in thatthe surface lighting element (50) has a flexible, flat cooling layer (82) on a rear side of the circuit carrier (80), which is mechanically or materially connected to the circuit carrier (80), and / or a rain and dirt-repellent layer (84), wherein in particular the cooling layer (82) is shielded from the outside by the rain and dirt-repellent layer (84) or is designed as a rain and dirt-repellent layer (84), and / or has a, in particular removable, diffusion layer (86) and / or a directional grid on a front side of the circuit carrier (80) and / or that the circuit carrier (80) is provided with a reflective surface, in particular an aluminum layer, below the illuminating means (58).

7. Lighting unit (10) according to one of claims 1 to 6, characterized in thatthe circuit carrier (80) with the lighting means (58) and the electrical lines (60) is coated with a waterproof coating (88), in particular silicone, a lacquer or a laminate, wherein the waterproof coating in particular also covers the flexible printed circuit board tongue at least up to the housing of the control unit.

8. Lighting unit (10) according to one of claims 1 to 7, characterized in that the control unit (20) comprises, in particular waterproof, operating elements, in particular a membrane keyboard (32), and / or a wireless communication interface (36) via which the control unit (20) can be remotely controlled by means of a remote control unit (40) or a mobile terminal.

9. Lighting unit (10) according to claim 8, characterized in thatthe membrane keyboard (32) for electronic connection to electrical or electronic components in the housing (22) has an elongated flexible printed circuit board tongue (33) with conductor tracks, which is guided into the housing (22) through a further slot in a wall of the housing (22) and a cavity (29) filled with a sealing compound, which forms a baffle for the printed circuit board tongue (33).

10. Lighting unit (10) according to one of claims 1 to 9, characterized in that in a wall of the housing (22) of the control unit (20) there is provided an opening (37) with a pressure membrane which is connected in a watertight manner to an edge of the opening (37), wherein the pressure membrane is designed in particular up to a water column of 2 m.

11. A method for producing a lighting unit (10) with a flexible surface lighting body (50) and a control unit (20), in particular a lighting unit (10) according to one of claims 1 to 10, comprising the following steps: - arranging the flexible surface lighting body (50) on the edge of a housing of the control unit (20), - threading an elongated flexible printed circuit board tongue (57) of the flexible surface lighting body (50) through a slot (26) in a wall of the housing (22) of the control unit (20) and a cavity (27) forming a chicane, which is defined by an inner wall (27') with the wall of the housing (22) having the slot (26), and - producing a hermetic seal by filling the cavity (27) forming the chicane, including the threaded printed circuit board tongue (57), with a sealing compound.

12. Method according to claim 11, characterized in thatafter threading through and before or after creating the hermetic seal, an electrical connection is established between one or more contact surfaces on the circuit board tongue (57) and one or more electrical or electronic components in the housing (22) of the control unit (20).

13. Method according to claim 11 or 12, characterized in that the flexible surface lighting body (50) is connected to the housing (22) after arrangement and before or after threading and before or after producing a hermetic seal, wherein in particular a strain relief of the passage of the printed circuit board tongue (57) is realized by the hermetic seal.

14. Method according to one of claims 11 to 13, characterized in thatan operating element, in particular a membrane keyboard (32), is attached to the housing (22) of the control unit (20), wherein an elongated flexible printed circuit board tongue (33) of the operating element (32) is threaded into the housing (22) through a slot and a cavity (29) arranged directly inward of the slot and designed as a chicane, and the feedthrough is then hermetically sealed by encapsulating the cavity (29) forming the chicane with a sealing compound.

15. Method according to one of claims 11 to 14, characterized in thatsome or all of the method steps mentioned in claims 11 to 14 are carried out with an at least partially open housing (22) of the control unit (29) and the housing (22) is closed after completion of the hermetic connection or connections, wherein in particular two or more parts of the housing (22) are sealed against one another before closing by means of a sealing compound applied along their abutting edges.

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