Method for producing a structural film, more particularly light-guide film, and light-guide film produced using the method

Abstract

The invention relates to a method for producing a structural film, preferably a light-guide film, wherein an embossing structure (6) of an embossing body (4), more particularly of an embossing roller, is used to emboss a film structure corresponding to the embossing structure (6) into a film material layer. To optimise the realisation of the film structure, the invention proposes that to form the embossing structure (6), the embossing structure (6) is embossed into the embossing body (4) with a profile (5) of a profile object (3), wherein the profile (5) is generated by means of an additive manufacturing method, more particularly a ceramic 3D printing method. The invention furthermore relates to a device for producing a structural film and to a light-guide film.

Description

[0001] Method for producing a structural film, in particular a light-directing film, and light-directing film produced thereby

[0002] The invention relates to a method for producing a structural film, preferably a light-directing film, wherein a film structure corresponding to the embossed structure is embossed into a film material layer using an embossed structure of an embossing body, in particular an embossing roller.

[0003] Furthermore, the invention relates to a device for producing a structural film, in particular a light-directing film.

[0004] Furthermore, the invention relates to a light-guiding film for changing a luminous intensity distribution of a light emitted by a light source, wherein the light-guiding film has a film material layer with a film structure in order to change a direction of a light of the light source impinging on the film structure, wherein the film structure is formed with structural elements designed as elevations and / or depressions.

[0005] As a further development of optics in luminaires for light control, film-based optics, so-called light-directing films, with an average thickness of less than 1 mm, were developed. Typically, a film structure with raised and lowered areas is embossed into the surface of a film to change the direction of light incident on the film structure. Typically, the light-directing film is placed in front of a light source in a luminaire to use the light-directing film to change the luminous intensity distribution of the light emitted by the light source.

[0006] The industrial production of light-directing films is usually carried out by embossing a film structure corresponding to the embossed structure into a film or its film material using an embossing roller whose surface has an embossed structure. The ability of the light-directing film to change a light intensity distribution in the desired manner depends to a large extent on the accuracy of the film structure embossed into the film and thus on the accuracy with which the embossed structure is introduced into the embossing roller. It is known to introduce the embossed structure into the embossing roller by means of machining or by means of laser ablation by removing material from a surface of the embossing roller. Particularly with a complex film structure or embossed structure, usually with defined changes in curvature, it often proves difficult to implement a desired, usually pre-calculated, film structure or embossed structure.

[0007] This is where the invention comes in. The object of the invention is to provide a method of the type mentioned above for producing a structural film, which enables an optimized implementation of the film structure of the structural film.

[0008] A further object of the invention is to provide a device of the type mentioned at the outset for producing a structural film, which enables an optimized implementation of a film structure of the structural film.

[0009] Furthermore, it is an object of the invention to provide a light-directing film of the type mentioned at the outset, which has an optimized film structure for changing a light intensity distribution.

[0010] The procedural problem is solved according to the invention in that, in order to form the embossed structure, the embossed structure is embossed into the embossed body with a profile of a profiled object, wherein the profile is generated by an additive manufacturing process, in particular a ceramic 3D printing process.

[0011] The invention is based on the idea of ​​optimizing the film structure by improving a structure formation process during the production of the structured film. For this purpose, it has proven advantageous to generate a structure, which is ultimately implemented by embossing a film material layer with an embossed structure of an embossed body, in a separate production step with high precision, decoupled from the embossed body.

[0012] If a profiled object with a profile is provided in order to emboss the embossed structure into the embossed body with the profile, a decoupling of the profile from the embossed structure is achievable. If the profile is generated or formed using an additive manufacturing process, a high level of accuracy and / or complex profile shape can be practically implemented. The embossed structure can be implemented by embossing the embossed body with the embossed object or the profile. The film structure can be implemented by embossing the film material layer with the embossed structure. The embossed structure is usually introduced into a surface of the embossed body. It is advantageous if the profile is pressed onto the embossed body so that the embossed structure is formed by deformation of a surface of the embossed body. The film structure is usually introduced into the film material layer, in particular a surface of the film material layer.For this purpose, the embossed structure is usually pressed onto the film material layer so that the film structure is formed by deformation of a surface of the film material layer. Typically, the film material layer forms a film, particularly after embossing or after the embossing of the film structure into the film material layer has been completed. The film then generally has the film structure. The film material layer can be liquid, semi-liquid, or solid at the start of the embossing of the film structure. At one end, or after the embossing of the film structure has been completed, the film material layer is usually in a solid state or with a film structure in a solid state. Typically, the film material layer in a solid state is referred to as a film.Often, during the embossing of the film structure into the film material layer, the film material layer cools, resulting in a solid structure. This is especially true if the film material layer is in a liquid or semi-liquid state during the embossing of the film structure. The film can be formed by solidifying the film material layer during the embossing of the film structure into the film material layer.

[0013] Typically, the embossed structure is designed to correspond, in particular, to the shape of the profile, usually as a negative image. Typically, the foil structure is designed to correspond, in particular, to the shape of the embossed structure, usually as a negative image. The profile is typically generated using an additive manufacturing process, after which the embossed structure is embossed into the embossed body using the profile, and then the foil structure is embossed into the foil material layer using the embossed structure.

[0014] The additive manufacturing process is preferably a 3D printing process, particularly preferably a ceramic 3D printing process. In this way, the profile can be generated with high precision and, in particular, with a complex shape. Typically, in a ceramic 3D printing process, a ceramic material is applied layer by layer to generate a three-dimensional structure. The profile is preferably formed with, in particular, a ceramic material, preferably zirconium oxide or zirconium dioxide. The ceramic material can be formed with, in particular, aluminum oxide, zirconium oxide, silicon nitride, and / or silicon carbide. The ceramic material can be formed from another ceramic material known to those skilled in the art that is suitable for additive manufacturing. Typically, the embossed structure of the embossed body is formed with, in particular, metal, in particular a metal alloy.By embossing the embossed structure with the profile, the shape of the profile can be formed with high precision corresponding to the profile.

[0015] Embossing or embossing usually refers to the creation of a structure by means of an embossing process, whereby a second structure corresponding to the shape of the first structure, usually as a negative image, is formed by pressing a first structure of an embossed object against an object to be embossed or its surface in the object to be embossed, usually with deformation of a surface of the object to be embossed.

[0016] Typically, the structural film comprises the film material layer, in particular the film, or is formed from it. The structural film is preferably a light-directing film for changing the luminous intensity distribution of light emitted by a light source. The film structure of the light-directing film is typically designed to change the direction of light from the light source impinging on the film structure by refraction and / or reflection and / or scattering of the light at the film structure, with refraction being preferred in this case. It can be expediently provided that the light reflection occurs under total internal reflection of light impinging on the light-directing film.The term light in this context is to be understood as a synonym for electromagnetic radiation with a wavelength which lies in a range visible to the human eye, in an ultraviolet range, also called UV range, or in an infrared range, also called IR range, of the electromagnetic wave spectrum. The light source can be, for example, a light source, in particular a light source of a lamp, or the sun. The light source can, for example, be formed with one or more LEDs. The profile is usually formed with a surface of the profile object. The embossed structure is generally formed with a surface of the embossed body or is introduced into it. It has proven useful if the profile object and / or the embossed body are cylindrical. For this purpose, the profile object and / or the embossed body can be essentially cylindrical.The profiled article can be a profiled roller. The embossing body can be an embossing roller. Alternatively, the embossing body can be a forming belt. The profile can be formed with a peripheral surface of the profiled roller or the forming belt. The embossed structure can be formed with a peripheral surface of the embossing roller. It is advantageous if the profiled article and the embossing body are rolled onto one another in order to emboss the embossed structure into the embossing body using the profile. The profile and / or a surface of the embossing body can each be rotated about a rotational axis in order to emboss the embossed structure into the surface of the embossing body using the profile.

[0017] To ensure the robustness of the embossed structure, it is advantageous if the embossed structure is formed with a metal material of the embossed body. The metal material can be a metal alloy, in particular an iron alloy, preferably steel, or an aluminum-based alloy or a copper-based alloy, such as brass or bronze, or a nickel-based alloy. The metal material can be formed with, in particular from, titanium, aluminum, copper, gold and / or iron. In particular, the metal material can be a shape memory material, such as nitinol, preferably with a transformation temperature which is less than 20°C. It is advantageous if the hardness of the embossed structure is increased during and / or after deformation of the metal material by means of the profile. This can be achieved by plastic deformation of the metal material and / or by metallurgical hardening of the metal material and / or by applying a hardening layer to the metal material.As a rule, the average hardness of the hardened layer is greater than the average hardness of the metal material. The deformation of the metal material by means of the profile is usually carried out in order to imprint the embossed structure into the embossed body. Metallurgical hardening usually comprises heating and / or cooling, in particular quenching, of the metal material. It is expedient if at least the cooling takes place during and / or after the deformation of the metal material. In particular, the heating can take place before and / or during the deformation of the metal material. The heating of the metal material can be carried out using a heating device, for example an electrical resistance heater. The cooling can be carried out using a cooling device, in particular by means of gas cooling, in particular air cooling, and / or liquid cooling, in particular oil cooling or water cooling.

[0018] A high level of robustness can be achieved if a strength layer which has a greater average strength and / or a greater average hardness than the metal material of the embossed structure is applied to the embossed structure, at least in some areas, or is formed as part of the embossed structure. The strength layer can be applied to the embossed structure by means of chemical vapor deposition, also referred to as CVD, and / or by means of physical vapor deposition, also referred to as PVD, and / or by means of electrolytic deposition and / or by means of chemical coating. The embossed structure can expediently have a plurality of areas covered with such strength layers. It can be expedient if such a strength layer is applied to a large part, in particular substantially the entirety, of the embossed structure. The strength layer can be the aforementioned coating layer. It is advantageous if the chemical coating is applied with orby chemical nickel plating, also known as electroless nickel plating. Chemical nickel plating is typically an autocatalytic reduction process, whereby nickel, often nickel-phosphorus and / or nickel-boron, is deposited as the coating material. The strength layer can be formed with, in particular, essentially nickel, in particular nickel-phosphorus and / or nickel-boron. Chemical nickel plating is generally implemented as an electroless deposition, whereby further deposition is usually catalyzed by the deposited coating material. This enables a particularly contour-accurate coating or formation of the strength layer.

[0019] Typically, the profile, embossed structure, or film structure is each formed with structural elements configured as elevations and / or depressions. The structural elements of the profile, embossed structure, and film structure can be designed differently. Frequently, the structural elements of the profile are referred to as profile structural elements, the structural elements of the embossed structure as embossed structural elements, and the structural elements of the film structure as film structural elements. It is advantageous if the average height of the structural elements is between 10 pm and 500 pm, in particular between 80 pm and 200 pm. A height typically refers to a distance between the highest point of an elevation and the lowest point of a depression, in particular one adjacent to the elevation. Such a height can be generated with high precision using the additive manufacturing process and, in particular, enables efficient light guidance.It is particularly advantageous if the average height is less than 80 pm, especially between 10 pm and 80 pm. Such a structure is barely visible to the naked eye. The height of the structural elements is usually measured orthogonally to a longitudinal extent and orthogonally to a width of the profile, embossed structure, or foil structure. The height is usually smaller than a length and smaller than a width of the profile, embossed structure, or foil structure.

[0020] It is advantageous if the structural elements are spaced apart from one another. This makes it possible to minimize or prevent undesired light wave transmission effects between structural elements of the film structure in a film structure. Such light wave transmission effects can manifest themselves, for example, as optically visible circles, rings or stripes. It has proven useful if the average spacing of the structural elements is from 5 pm to 200 pm, in particular from 5 pm to 80 pm. The structural elements can be arranged in several rows oriented in an arrangement direction, wherein the rows are preferably aligned parallel to one another. The structural elements of immediately adjacent rows can expediently be arranged offset from one another in the direction of the arrangement.

[0021] The embossed structure, in particular its structural elements, typically forms a negative image of the profile, in particular its structural elements. The foil structure, in particular its structural elements, typically forms a positive image of the profile, in particular its structural elements.

[0022] It is advantageous if at least one of the structural elements has a surface region which forms a surface of revolution, wherein the surface of revolution forms an outer contour in a cross-section along a rotation axis of the surface of revolution, which outer contour is formed with a plurality of ellipse segments which are adjacent to one another by a corner each. The axis of rotation can lie in a cross-sectional plane of the cross-section. The axis of rotation generally represents the axis of rotation with which the surface of revolution is defined by rotating a curve around the axis of rotation. Typically, two adjacent ellipse segments are connected to one another via a corner. It is advantageous if the axis of rotation essentially runs through a corner. The surface of revolution usually represents a lateral surface of a rotary body which has the axis of rotation.The ellipse segments can be mirror-symmetrical to each other with respect to the rotation axis. The highest point of the structural element can be formed by a corner. It has proven effective if the outer contour is formed with or from two ellipse segments that adjoin each other at a corner. The corner is preferably intersected by the rotation axis. It is advantageous if the corner forms the highest point of the structural element. The two ellipse segments can be mirror-symmetrical to each other with respect to the rotation axis.

[0023] It is advantageous if at least one of the structural elements has a surface segment with the shape of a section of an ellipsoid cut off by a cutting plane. With an ellipsoidal shape, efficient light guidance and simultaneous glare control can be achieved. However, it is usually difficult in practice to reproduce an ellipsoidal surface effectively or with sufficient accuracy in a film structure. This can be achieved using the additive manufacturing process and, by combining the formation of a corresponding profile of the profiled object in order to emboss a corresponding embossed structure into the embossed body with the profile, a film structure or a film structure element with such a surface segment or such an ellipsoidal shape can ultimately be implemented by embossing the film material layer, in particular film, with the embossed structure.This is especially true if the additive manufacturing process is a 3D printing process, in particular a ceramic 3D printing process, and the embossed structure is formed with, in particular from, metal. A surface of the structural element usually has the surface segment. In particular, at least one of the profile structural elements or the embossed structural elements or the film structural elements can be designed in this way. The ellipsoid can be an ellipsoid of revolution. The ellipsoid is usually defined by three semi-axes which, starting from the center of the ellipsoid, are aligned orthogonally to one another, in particular corresponding to the axes of a Cartesian coordinate system. Usually, one of the semi-axes is a height semi-axis which is aligned essentially parallel to a height of the profile or the embossed structure or the film structure. In particular, the three semi-axes can be designed with different lengths orthe ellipsoid can be triaxial. With appropriate implementation of the film structure or its structural element, a high degree of luminous intensity distribution can be efficiently adapted to a specific application while simultaneously achieving a high level of glare control. It can be advantageous if two of the semi-axes have the same length, which length is different from the length of the other semi-axis, in particular the semi-height axis. This makes it possible to achieve a pronounced rotational symmetry of the luminous intensity distribution. In a simple form, the three semi-axes can essentially have the same length, or the ellipsoid of revolution can form a sphere. It has proven useful if the cutting plane is oriented orthogonal to one of the semi-axes, in particular the semi-height axis, in order to define or separate the partial section of the ellipsoid.A glare control value to be implemented, in particular UGR (unified glare rating), can be efficiently selected by varying the distance of the cutting plane from the center of the ellipsoid. A particularly high glare control value can be achieved if the cutting plane is orthogonal to a first semi-axis of the semi-axes, with the cutting plane intersecting the first semi-axis starting from the center of the ellipsoid at a first third of the length of the first semi-axis. A good glare control value with a broader luminous intensity distribution can usually be achieved if the first cutting plane intersects the first semi-axis starting from the center of the ellipsoid at a second third of the length of the first semi-axis.If the first cutting plane intersects the first semi-axis, starting from the center of the ellipsoid, at a third of a length of the first semi-axis, a less pronounced glare control value can usually be achieved, but in return a particularly broad luminous intensity distribution. Starting from the center of the ellipsoid, the second third is subordinate to the first third and the third third to the second third. The first semi-axis is preferably the semi-height axis. The structural element is usually arranged on a base surface protruding from the base surface. The base surface is usually part of the profile or the embossed structure or the film structure, usually its surface. The base surface is generally a base plane. It can be provided that the surface segment or the surface region directly borders the base surface, preferably along an entire circumference of the surface segment.It is advantageous if the surface segment or surface region is arranged on a cylindrical surface section of the structural element. Typically, the cylindrical surface section protrudes from the base surface. The cylindrical surface section can be directly adjacent to the base surface, preferably along the entire circumference of the cylindrical surface section. In this way, a particularly defined light intensity distribution can be achieved.

[0024] The profile, embossed structure, or film structure can advantageously comprise such structural elements. Typically, several, in particular a majority, of the structural elements of the profile, embossed structure, or film structure are designed as described.

[0025] Depending on the intended use of a structural film designed as a light-directing film, it is preferred if the structural elements of the film structure of the light-directing film are designed as elevations or depressions. If the light-directing film is designed for a lighting device, such as a lamp, it is preferred if the structural elements are designed as elevations. Although less preferred, the structural elements can alternatively be designed as depressions. If the light-directing film is used for a solar module, in particular as described in this document, it is preferred if the structural elements are designed as depressions. In particular, glare from a solar module, in particular when the light conversion element is a solar cell, can be reduced as a result. Although less preferred, the structural elements can alternatively be designed as elevations.

[0026] It is advantageous if a film structure, as described in particular, is embossed on one side or both sides of the film material layer, in particular film. This allows precise adaptation to an application requirement. The sides usually refer to the sides of the film material layer defined by a length and a width of the film material layer. The height of the film material layer is usually smaller than the length and smaller than the width of the film material layer. This applies analogously if the film material layer forms a film or is designed as such. The film structures that are embossed into the two sides of the film material layer or film usually differ from one another.

[0027] It is advantageous if the film material layer, in particular film, is curved along a longitudinal extent and / or along a width extent of the film material layer. In particular, if the structured film is a light-directing film, a desired light intensity distribution can be further optimized in this way. As a rule, a coordination between a film structure and a curvature of the film material layer or film is required, in particular in order to achieve a desired light deflection with a light-directing film. This is made possible with high precision by combining additive manufacturing processes and the formation of the embossed structure with the profiled article. A height of the film material layer, in particular film, is usually measured orthogonal to a longitudinal extent and orthogonal to a width extent of the film material layer or film.The height is usually smaller than a length and smaller than a width of the film material layer or film.

[0028] It is advantageous if the structural film, in particular a light-guiding film, is formed with an average thickness of less than 900 μm, in particular less than 600 μm, preferably less than 400 μm. This allows the structural film to achieve a degree of flexibility that allows the structural film to be precisely applied to the shape of a curved surface, for example, a curved cover of a light fixture. In the case of a light-guiding film, advantageous light transmission behavior can be achieved through the light-guiding film, in particular with low light scattering on a material of the light-guiding film.

[0029] It is advantageous if the structural film, in particular light-directing film, is designed or arranged with a curved shape. The light-directing film, designed with a curved shape, can expediently be arranged in the region of a light source for light deflection. The curved shape enables a greater coverage of a solid angle with the light-directing film, in which solid angle the light source emits light. Advantageously, the light-directing film can essentially cover an entire half-space above a light source in order to capture light emitted by the light source into the half-space with the light-directing film. The light source can expediently be formed with one or more LEDs. The curved shape of the structural film, in particular light-directing film, can increase the mechanical stability of the structural film. It is advantageous if the structural film, in particular light-directing film, has the curved shape in a self-supporting manner.In particular, the structural film can thereby form a cover, for example a cover for a light source.

[0030] The embossed structure is preferably embossed into a surface of the embossed body by rotating the profiled object and / or by rotating the embossing body with the profile. The profiled object is preferably designed as a profile roller. The embossing body can be designed as an embossing roller or as a forming belt. The profile roller can be rotatable about a rotation axis which is in particular parallel to a longitudinal axis of the profile roller. The embossing roller can be rotatable about a rotation axis which is in particular parallel to a longitudinal axis of the embossing roller. The film structure is preferably embossed into the film material layer, in particular a surface of the film material layer, by rotating the embossing body with the embossed structure. Typically, the embossing roller is guided in a rolling manner over the film material layer in order to emboss the film structure into the film material layer, in particular its surface, with the embossed structure.

[0031] It has proven effective to produce the film material layer using an extrusion process, whereby a granulate, usually plastic granulate, is heated and then pressed through a shaping opening or die. This can be done using an extrusion device, whereby the shaping opening or die is part of the extrusion device. The embossing of the film structure into the film material layer usually follows the extrusion process. It is expedient if the film material layer or film is heated for embossing the film structure into the film material layer or film. For this purpose, a temperature control device, which is designed, for example, as an electrical resistance heater, can be provided. This applies in particular if the film material layer is in a solid state before the film structure is embossed.It is preferred if the film material layer is liquid or partially liquid when the film structure is embossed. The film structure or the film material layer can be cooled during embossing of the film structure so that the film structure or the film material layer changes into a solid state. Cooling can occur passively by dissipating heat to an environment or to the embossing body. Alternatively or cumulatively, cooling can occur actively with a cooling device, for example by means of gas cooling, in particular air cooling, and / or liquid cooling, in particular oil cooling or water cooling. The cooling device can be designed as part of the embossing body or as part of a support surface on which a side of the film material layer or film facing away from the embossing body rests during embossing of the film structure.For example, the embossing body can be cooled with the cooling device in order to cool the film material layer or film structure during embossing of the film structure by transferring heat to the embossing body. The embossing body can expediently have one or more coolant transport channels in order to conduct a coolant through the coolant transport channels in order to cool the embossing body. The coolant can be liquid and / or gaseous, for example water. The coolant transport channels can form a coolant circuit. It is advantageous if the film material layer emerges from the shaping opening or die in a liquid or partially liquid state and does not change into a solid state until the film structure is embossed. The film material layer then usually only changes into the solid state when the film structure is introduced into it.

[0032] The film material layer or film is usually formed with, in particular from, plastic. The plastic can be a polyamide, a polyurethane, a polyester, a polyolefin, a polycarbonate, a polymethyl methacrylate and / or an acrylonitrile-butadiene-styrene copolymer. The film material layer or film is usually transparent or semi-transparent. Appropriately, a conventional transparent or semi-transparent curable plastic, in particular a thermoplastic, can be used as the plastic. The plastic can be curable, for example, by means of UV radiation, by gas contact and / or by means of a chemical activator. It can be expedient if the film material layer or film is formed with, in particular from, metal.It is practical if the profile is generated as part of a profile roll shell of the profile roll using the additive manufacturing process, whereby the profile roll shell is detachably connected to a shell carrier of the profile roll. This allows the profile roll shell to be detached from the shell carrier for generating the profile and / or exchanging the profile roll shell with another profile roll shell. The profile roll shell can, for example, be sleeve-shaped. The profile roll can expediently have several profile roll shells as part of which the profile is generated using the additive manufacturing process. Typically, the profile roll shell or the profile roll shells form an outer surface or shell surface of the profile roll when connected to the shell carrier.

[0033] It is advantageous if the embossed structure with the profile is embossed into an embossing roller shell of the embossing roller, wherein the embossing roller shell is detachably connected to a shell surface carrier of the embossing roller. This allows the embossing roller shell to be detached from the shell carrier for the introduction of the embossed structure and / or for the replacement of the embossing roller shell with another embossing roller shell. The embossing roller shell can, for example, be sleeve-shaped. The embossing roller shell can then form the surface of the embossing body into which the embossed structure is embossed. The embossing roller can expediently have several embossing roller shells into which the embossed structure with the profile is embossed. Typically, the embossing roller shell or the embossing roller shells, when connected to the shell carrier, form an outer surface or shell surface of the embossing roller.

[0034] It is practical if the structural film is arranged in a fastening frame in order to position the structural film with the fastening frame for a specific application. If the structural film is a light-directing film, the light-directing film can be positioned with the fastening frame relative to a light source in order to change a light intensity distribution of the light source. For example, the fastening frame can be designed as part of a lighting device, as described in particular in this document, or as part of a solar module, as described in particular in this document. It is advantageous if the structural film is connected to the fastening frame with an elastically deformable and / or plastically deformable connecting element, so that when the structural film expands due to heat, the structural film can expand under, in particular elastic and / or plastic, deformation of the connecting element.The structural film is preferably connected to the fastening frame under, in particular, predetermined prestressing of the structural film. The connecting material is preferably designed such that the, in particular predetermined, prestressing is maintained during thermal expansion of the structural film. For this purpose, the connecting element can be designed to exert a defined, preferably essentially constant, mechanical stress on the structural film. The connecting element can be a, in particular elastically and / or plastically deformable, connecting material or spring element. Typically, an edge region of the structural film, in particular a light-directing film, is connected to the fastening frame so that, in the deployed state, light can penetrate or transmit through a central region of the structural film. As a rule, the central region is surrounded by the edge region, in particular circumferentially.The edge region can expediently be supported by the fastening frame. The fastening frame is preferably formed substantially with, in particular from, plastic. It is advantageous if the fastening frame is designed to correspond in shape to a fastening frame receptacle, so that the fastening frame and the fastening frame receptacle can be connected to one another in a form-fitting manner, in particular by pushing the fastening frame into the fastening frame receptacle. The fastening frame can be detachably connectable to the fastening frame receptacle. The fastening frame receptacle can be part of the lighting device or the solar module. The fastening frame can have an adhesive layer on at least one, preferably several sides, in particular outer sides, in order to connect the fastening frame to a structure of the lighting device or the solar module, wherein the structure can be the fastening frame receptacle.

[0035] It is advantageous if the structural film is formed at least in sections with a frosted area. The structural film can expediently be formed with several frosted areas. A frosted area is usually an area which causes diffusive light scattering of a light incident on the frosted area, in particular through the frosted area. If the structural film is a light-directing film, a combination of a change in the luminous intensity distribution of light emitted by a light source through light refraction at the film structure and light scattering at the frosted area can occur in this way. The frosted area is preferably arranged on a side of the film material layer or film opposite the film structure and / or less preferably on a side of the film material layer or film having the film structure.The matt area can be formed with a matting layer, in particular a film-like one, which is arranged on the film material layer, in particular on a side of the film material layer opposite the film structure. The matting layer can be glued to the film material layer. It can be expedient if a large part, in particular substantially all of one side of the film material layer is designed as a matt area. The above applies in particular to the film material layer implemented as a film. It is advantageous if the matt area is introduced into the material layer by rolling a rubber surface on a material layer. The matt area can be introduced into the material layer using a matting roller, in particular a rubber roller, usually by rolling an outer surface of the matting roller on the material layer. The material layer can be the film material layer orIt can be a film or can be part of the matting layer or the matting layer. The rubber surface can be integrated with the outer surface of the matting roller. Typically, the rubber surface or the outer surface of the matting roller rolls in the opposite direction to the movement, particularly the translational movement, of the material layer. It is advantageous if the matted area has an average roughness R. a , also called the mean roughness, is formed between 2 pm and 20 pm, in particular between 5 pm and 15 pm, preferably between 7 pm and 12 pm. This reduces the potential for glare, particularly when the structured film is used as a light-directing film.

[0036] It is advantageous if the film structure is heated in order to increase the smoothness of a film structure surface. This is usually done after the film structure has been embossed with the embossing body or embossing profile. An increase in the smoothness or a reduction in the roughness of the film structure surface usually results from heating the film structure as a result of the surface tension of the film structure surface. For this purpose, the film structure surface can expediently be heated to a temperature of at least 0.8 times, in particular at least 0.9 times, a melting temperature or glass transition temperature of the film structure surface or its material. It can be advantageous for this purpose if the film structure surface is melted. Expediently, the film structure surface can be heated to a temperature between 0.9 times and 1.2 times a melting temperature or glass transition temperature of the film structure surface orwhose material is heated, preferably to a temperature between the melting temperature or glass transition temperature and 1.2 times the melting temperature or glass transition temperature.

[0037] The film structure surface can be heated to a temperature between the melting temperature or glass transition temperature and a temperature at which thermal degradation of the plastic begins. Typically, the film structure surface is heated in such a way, in particular to a temperature greater than or equal to the melting temperature or glass transition temperature of the film structure surface or its material, that the film structure, in particular the structural elements of the film structure, are retained. The purpose is generally to smooth the film structure surface without significantly impairing the film structure, in particular a shape of the structural elements. Typically, the film structure surface is cooled or allowed to cool after heating so that the film structure surface solidifies. Expediently, the film structure can be cooled after heating using active cooling.The film structure can be heated using a heating device, for example, an electrical resistance heater, a flame, a hot gas exposure, for example, hot air, infrared radiation, and / or laser radiation. The film structure can be cooled using a cooling device, for example, air cooling and / or water cooling. The temperature of the film structure surface is usually an average temperature of the film structure surface. It is advantageous if the film structure surface is heated such that a temperature of the

[0038] Film structure surface is at least twice, in particular at least three times, as high as an average temperature of a remainder of the film. It has proven useful if the film structure surface is heated to a temperature greater than a glass transition temperature of a material of the film structure surface, while a remainder of the film has an average temperature lower than the glass transition temperature, in particular lower than 0.9%, preferably lower than 0.8%, particularly preferably lower than 0.5%, of the glass transition temperature of a material of the remainder of the film or remains at such a temperature until solidification of the film structure surface. It is preferred if dimensional stability of the film, in particular the film structure, is not significantly impaired from the heating of the film structure surface until subsequent solidification of the film structure surface.To this end, it is advantageous if, from heating of the film structure surface until subsequent solidification of the film structure surface, an equilibrium temperature of the film material of the film along a cross-section of the film remains lower than a glass transition temperature or melting temperature of the film material. The cross-section is usually oriented towards a height of the film. This ensures efficient heat dissipation with sufficient structural stability of the film. In particular, active cooling can then be dispensed with. The stated temperatures usually refer to a temperature in °C. If the material of the film structure surface or the material of the film or the material of a remainder of the film has a glass transition temperature, the aforementioned melting temperature refers in particular to the glass transition temperature of the respective material. If the material of the film structure surface or the material of the film orthe material of a remainder of the film has a melting temperature, the aforementioned glass transition temperature refers in particular to the melting temperature of the respective material.

[0039] It has proven useful to apply a coating to the film structure, at least in certain areas, in order to increase its smoothness. Increasing the smoothness or reducing the roughness of the structural film or its surface structure is usually achieved by leveling out any unevenness and / or pores in the film structure. The coating is preferably applied to the film structure in liquid form and then cured. The coating can be a layer of varnish, for example. It is advantageous if the refractive index of the coating, particularly in the cured state, essentially corresponds to the refractive index of the film material layer, in particular the film, or the film structure. This can prevent light refraction at a boundary layer between the film structure and the coating. The surface structure of the structural film usually corresponds essentially to the film structure.The film structure can expediently have a plurality of areas covered with such a coating. It can be expedient if a coating is applied to a large part, in particular substantially the entirety, of the film structure. This can apply to a film structure on one or both sides of the film material layer or film. The coating is usually transparent. The coating, in particular the lacquer layer, can be formed with acrylic acid ester, polyester resin, epoxy resin and / or silicone resin. The lacquer layer can also be formed with another transparent or semi-transparent material suitable for this purpose. Expediently, the coating can comprise a curing accelerator. It is advantageous if the coating is actively cured. Expediently, the coating can be curable or can be cured by heating and / or irradiation with ultraviolet radiation.For this purpose, a heating device or a source of ultraviolet radiation can be provided. It is advantageous if the film material layer, in particular film, or film structure is oriented during application of the coating such that excess coating material can run off the coating. For this purpose, the film material layer, in particular its longitudinal extent, can expediently be tilted relative to a horizontal orientation of the film material layer or its longitudinal extent during application of the coating. This applies analogously to the film. Expediently, it can be provided that excess coating material is blown off with a gas flow, in particular an air flow. For this purpose, a gas nozzle, in particular in the form of an air knife, can be provided, with which the gas flow is directed onto the coating.It is advantageous if the coating is applied to the film structure with a varying thickness. It is practical if a coating applied to structural elements, in particular their respective surface segments, has a greater thickness than a coating applied to an intermediate region between the structural elements. In particular, no coating can be applied to the intermediate region. The intermediate region is typically the area of ​​the film structure by which adjacent structural elements are spaced from one another.

[0040] It has been shown that it is advantageous if one or more surface regions of the structural film, in particular the light-guiding film, are formed with a specific roughness. For this purpose, a surface region of the structural film, in particular the light-guiding film, can advantageously be formed with an average roughness R a, also called mean roughness, between 0.4 pm and 0.9 pm and / or an average roughness depth R z, also called ten-point height, between 3 pm and 7 pm. This achieves homogenization of the light incident on the structural film, in particular the light-directing film, and / or the film structure. Undesirable solid angle-dependent intensity fluctuations in the luminous intensity distribution formed by the light-directing film are minimized in this way. Such intensity fluctuations can be caused, for example, by light reflections within a light source structure, for example when the light source is formed with several spatially spaced light sources. It has proven useful if both the average roughness and the average roughness depth have values ​​corresponding to the aforementioned value ranges, whereby a particularly uniform homogenization is achieved. An average roughness between 0.5 pm and 0.7 pm and / or an average roughness depth between 4 pm and 5 pm have proven to be particularly practical.Roughness values ​​in this range enable sufficient homogenization without having to take into account scattering effects caused by the roughness. In principle, homogenization can be achieved if one of the surfaces of the structural film, in particular light-directing film, is formed with surface regions with a roughness corresponding to the aforementioned value ranges for the average roughness and / or average roughness depth. This can be the surface of the structural film, in particular light-directing film, into which the film structure is embossed or the one opposite it. In order to achieve greater homogenization, however, both surfaces of the structural film, in particular light-directing film, can also be formed with surface regions of such roughness. It is preferred if outer surfaces of the structural elements are formed with an average roughness and / or average roughness depth corresponding to the aforementioned value ranges.In particular, both the light guidance and the homogenization of the light incident on the light-guiding film can be achieved by the embossed film structure. It is advantageous if at least half, preferably at least a predominant area, of a respective surface of the structural film, in particular the light-guiding film, represents such surface regions.

[0041] At the same time, it has been found that the luminous intensity distribution can be formed with particularly sharp delineation if one or more surface regions of the structural film, in particular light-directing film, are designed to be particularly smooth. It is advantageous for this purpose if a surface region of the structural film, in particular light-directing film, is designed with an average roughness of less than 0.25 pm and / or an average surface roughness of less than 2 pm. Here, too, the surface regions can be part of that surface of the structural film, in particular light-directing film, into which the film structure is embossed, or the surface opposite it. It is advantageous if at least half, preferably at least a predominant area portion, of a respective surface of the structural film, in particular light-directing film, represents such surface regions.In order to utilize the aforementioned homogenization as well as to promote the formation of a sharply defined luminous intensity distribution, it has proven to be a good compromise to form one of the surfaces of the structural film, in particular the light-guiding film, with one or more surface regions of a roughness corresponding to the aforementioned value ranges for a smooth surface and the other surface of the light-guiding film with surface regions of a roughness corresponding to the aforementioned value ranges for a rough surface or a surface with a certain roughness.

[0042] It is advantageous if a structural film composite or a method for producing a structural film composite is provided, wherein the structural film composite is or will be formed with a plurality of structural films connected to one another. The structural films can be produced or formed as described in this document. Preferably, the structural films have different film structures. The structural films are usually arranged one above the other along a stacking direction. The stacking direction is generally oriented substantially parallel to a height of the respective structural films. The structural films are usually connected to one another to form a stack, wherein the stack is in particular translucent. The structural films can be connected to one another in a materially bonded and / or force-fit manner, for example by being glued or laminated to one another. The structural films are preferably designed as light-directing films.This allows for a specially tailored luminous intensity distribution to be implemented. The light-directing films are typically arranged such that their film structures overlap each other. To change the luminous intensity distribution of light emitted by a light source, the light is successively refracted by the film structures and transmitted through the light-directing films. The height of the structured film is typically orthogonal to a length and orthogonal to a width of the structured film. The height is usually smaller than the length and smaller than the width of the structured film.

[0043] Advantageously, a method for producing a lighting device can be provided, wherein the lighting device has a light-directing film for changing a luminous intensity distribution of a light source, wherein the light-directing film is a structured film which is produced, in particular formed, as described in this document. According to the features and effects of a described method for producing a structured film, the lighting device can be formed with an optimized implementation of a film structure of the light-directing film. A lighting device with such a light-directing film can expediently be provided. In this way, the lighting device can have a light-directing film with an optimized film structure for changing a luminous intensity distribution of the light source. The light source can be part of the lighting device.The light-guiding film is typically designed to deflect light emitted by the light source using the film structure of the light-guiding film in order to change the light intensity distribution of the light source. The light source can be configured with one or more LEDs. The film structure of the light-guiding film can be arranged such that the film structure faces the light source or faces away from it.

[0044] It is advantageous if a method for producing a solar module for converting solar energy is provided, wherein the solar module has at least one light conversion element, such as a solar cell, and a light-directing film for changing a luminous intensity distribution of sunlight in order to direct sunlight with the light-directing film in the direction of the at least one light conversion element. Such a solar module can expediently be provided for converting solar energy. The light-directing film can be a structured film which is or will be produced, in particular formed, as described in this document. According to the features and effects of a described method for producing a structured film, the solar module can be formed with an optimized implementation of a film structure of the light-directing film.The light conversion element can be designed to convert solar energy into usable energy, in particular electrical energy and / or thermal energy and / or chemical energy. The solar module is typically designed to transmit the usable energy, in particular electrical energy or thermal energy, for use, for example to a storage device for storing the energy. The light conversion element can be a solar cell, also referred to as a photovoltaic cell, for converting solar energy into electrical energy. Alternatively or cumulatively, the light conversion element can be a heat collector designed to convert solar energy into thermal energy of a fluid in the collector. The heat collector typically has a fluid circuit for transporting the fluid in order to transmit thermal energy with the fluid.The film structure of the light-directing film can be arranged in such a way that the film structure is facing the sun or facing away from it in the state of use.

[0045] Advantageously, a device for producing a structural film is provided, wherein the device has a profiled object with a profile in order to use the profile to emboss an embossed structure into an embossed body, in order to use the embossed structure to emboss a film structure corresponding to the embossed structure into a film material layer or film, wherein the profile is generated or produced using an additive manufacturing process, in particular a ceramic 3D printing process. As described in particular above, this enables an optimized implementation of the embossed structure or the film structure. The profiled object can be used in particular in the process for producing a structural film, in particular as described in this document. Typically, an embossed structure is embossed into the embossed body, in particular a surface of the embossed body, using the profile of the profiled object.For this purpose, the profile is typically pressed onto the embossing body, so that the embossed structure is formed by deformation of a surface of the embossing body. The embossing body can expediently be part of the device. Typically, the profiled object and the embossing body are movable relative to one another such that an embossed structure corresponding to the profile can be embossed into the embossing body. For this purpose, the profiled object and / or embossing body can be moved relative to one another using a movement device of the device. The device can be used to implement a method for producing a structured film described in this document.

[0046] It is understood that the device, in particular the profiled object, can be designed according to the features and effects described in this document in the context of a method for producing a structural film, in particular above. The same applies analogously to the method for producing the structural film with regard to the device, in particular the profiled object.

[0047] It is advantageous if the profiled object is a profiled roller and / or the embossing body is an embossing roller in order to emboss an embossed structure into the embossed body by rolling the profiled object and the embossing body against each other with the profile. The profiled object or embossing body can be essentially cylindrical. The profile can be formed with a lateral surface of the profiled roller. For this purpose, the profiled roller or the profile can be mounted so as to be rotatable about a rotational axis of the profiled roller. The embossed structure can be formed with a lateral surface of the embossing roller. For this purpose, the embossing roller or its lateral surface can be mounted so as to be rotatable about a rotational axis of the embossing roller.

[0048] It is advantageous if a light-directing film is provided for changing a luminous intensity distribution of light emitted by a light source, wherein the light-directing film has a film material layer with a film structure in order to change a direction of light from the light source impinging on the film structure, wherein the film structure is formed with structural elements designed as elevations and / or depressions, also referred to as film structural elements, wherein at least one of the structural elements has a surface segment having a shape of a portion of an ellipsoid cut off by a cutting plane. The light-directing film can be a structural film which can be produced using the method for producing a structural film. With such a surface segment, efficient light guidance and simultaneous glare control can be implemented.The implementation of such a surface segment in a film structure of a light-directing film is achievable if an appropriately shaped profile of a profiled object is created using an additive manufacturing process in order to emboss a corresponding embossed structure into an embossed body with the profile, and finally a film structure or a structural element in the film material layer with such a surface segment is implemented by embossing the film material layer with the embossed structure. This applies in particular if the additive manufacturing process is a 3D printing process, in particular a ceramic 3D printing process, and the embossed structure is formed with, in particular from, metal. This makes it possible to implement a light-directing film with an optimized film structure for modifying a light intensity distribution. The film material layer can expediently be implemented as a film or form one, as described.

[0049] It is understood that the light-directing film can be designed according to the features and effects described in this document, in particular above, within the framework of a method for producing a structural film. The same applies analogously to the method for producing the structural film with regard to the light-directing film.

[0050] The dimensions of the elevations or depressions in the film structure are usually larger than one wavelength of the light from the light source incident on them. It is advantageous if the average height of the film structure elements is between 10 pm and 500 pm, in particular between 80 pm and 200 pm. A height usually refers to the distance between the highest point of an elevation and the lowest point of a depression, in particular one adjacent to the elevation. Such a height enables efficient light guidance and can be generated with high precision using the additive manufacturing process. It is particularly advantageous if the average height is less than 80 pm, in particular between 10 pm and 80 pm. Such a structure can hardly be perceived by the user with the naked eye.The height of the foil structure elements is usually measured orthogonally to a longitudinal dimension and orthogonally to a width dimension of the light-guiding foil or foil structure. The height is usually smaller than a length and smaller than a width of the light-guiding foil or foil structure.

[0051] It is advantageous if the film structural elements are spaced apart from one another. This minimizes or prevents unwanted light transmission effects between the film structural elements. Such light transmission effects can manifest themselves, for example, as optically visible circles, rings, or stripes in a state of use in which the light-directing film is used to redirect light from a light source. It has proven effective to have an average spacing of the film structural elements of 5 pm to 200 pm, particularly 5 pm to 80 pm.

[0052] The light-guiding film can expediently be designed as an optic, wherein a luminous intensity distribution of a light emitted by a light source is changed by the light being transmitted through the light-guiding film, the light being refracted at the film structure of the light-guiding film. Alternatively, the light-guiding film can be designed as a reflector, the light being reflected by the light-guiding film or at the film structure of the light-guiding film. Advantageously, a lighting device comprising a light source and a light-guiding film, in particular described in this document, can be provided in order to change a luminous intensity distribution of the light source with the light-guiding film. The light source can be implemented with a plurality of light sources, in particular spaced apart from one another. The light source, in particular the respective light source, can be implemented with an LED, in particular as an LED.The lighting device can be designed according to the features and effects described in this document, in particular in the context of a method for producing a structural film and / or a device for producing a structural film. This also applies analogously and in reverse to the method or device for producing a structural film with regard to the lighting device.

[0053] The light-guiding film is typically designed to deflect light emitted by the light source with the film structure of the light-guiding film in order to change a light intensity distribution of the light source. The film structure of the light-guiding film can be arranged such that the film structure faces the light source or faces away from it. The light-guiding film is typically arranged in front of the light source, in particular the light sources, at least partially, preferably essentially entirely, covering the light source, in particular the light sources, when viewed opposite to a main emission direction of light emitted by the lighting device and / or the light source, in particular the light sources. The light-guiding film can be arranged at a distance from the light source or in contact with the light source.The main emission direction of the light is generally a direction in which the light emitted by the lighting device and / or the light source has a maximum luminous intensity. A longitudinal direction of the light-directing film is typically arranged substantially orthogonal to the main emission direction of the light source. A top view typically refers to a view opposite a main emission direction of the light from the light source, in particular the illuminant. In particular, the top view can be a view substantially orthogonal to the light-directing film and / or to a notional arrangement surface in which the light source or illuminant is located. The notional arrangement surface can be a notional arrangement plane.

[0054] It is advantageous if the light-guiding film has an outer cover of the

[0055] The light-guiding film forms a lighting device through which outer cover, together with the lighting device, emits light from the light source to illuminate an environment. The light-guiding film can be curved along a longitudinal extent and / or along a width extent of the light-guiding film. It is advantageous if the light-guiding film is self-stable with respect to a shape and / or curvature of the light-guiding film. The light-guiding film, in particular a longitudinal extent and / or width extent of the light-guiding film, can be concavely or preferably convexly curved when viewed opposite a light emission direction of the lighting device.

[0056] It has proven useful if the lighting device has a lamp arrangement formed with a plurality of lamps of the lighting device that are spaced apart from one another along a longitudinal extent of the lamp arrangement. The lighting device can be a linear luminaire. The longitudinal extent of the lamp arrangement usually corresponds to a longitudinal axis of the lamp arrangement. It is advantageous if the respective lamp is designed to emit a greater radiant power, in particular a greater luminous flux, parallel to a first cross-sectional plane that is oriented orthogonal to the longitudinal extent of the lamp arrangement than parallel to a second cross-sectional plane that is oriented orthogonal to the first cross-sectional plane. The first cross-sectional plane and the second cross-sectional plane usually have an intersection line running through a center of an emission surface of the lamp.It is advantageous if the respective illuminant has an elongated, in particular rectangular shape, in particular an emission surface of the illuminant, wherein the respective illuminant is arranged such that a longitudinal axis of the shape is oriented transversely, in particular orthogonally, to the longitudinal extent or longitudinal axis of the illuminant arrangement. The emission surface usually refers to the surface over which the illuminant is designed to emit light. Preferably, the respective illuminant is an LED. The respective illuminant, in particular an emission surface normal of its emission surface, and / or a main radiation direction of the respective illuminant is usually oriented in a direction orthogonal to the longitudinal axis of the illuminant arrangement. It is advantageous if the light-directing film of the lighting device is arranged covering the illuminants when viewed onto the emission surfaces of the illuminants and / or is convexly curved.Preferably, the light-directing film is convexly curved in a cross-section orthogonal to the longitudinal direction of the illuminant arrangement with respect to a view of the emitting surfaces of the illuminants. A longitudinal direction of the light-directing film is preferably parallel to the longitudinal direction of the illuminant arrangement. The view of the emitting surface is usually a view parallel to an emitting surface normal of the emitting surfaces and / or counter to a main emission direction of the emitting surfaces. The illuminants of the illuminant arrangement are preferably arranged in a fictitious arrangement surface, in particular a fictitious arrangement plane. The illuminants of the illuminant arrangement can have one or more arrangement rows oriented in the direction of the longitudinal extent of the illuminant arrangement, each of a plurality of illuminants spaced apart, in particular in the longitudinal direction of the illuminant arrangement. The arrangement rows are usually oriented parallel to one another.It is advantageous if the illuminant arrangement is formed with a predominant number of the illuminants, preferably essentially all of the illuminants, of the lighting device. The longitudinal extension of the lighting device typically corresponds to a longitudinal extension of the illuminant arrangement.

[0057] In order to achieve a high degree of glare control, it is advantageous if a reflector structure is arranged in an area between the light source, in particular the illuminants, and the film structure of the light-guiding film in order to use the reflector structure to redirect a portion of the light emitted by the light source, in particular the respective illuminant, towards the light-guiding film. The light portion typically refers to large-angle light rays of the light emitted by the light source, in particular the respective illuminant, which large-angle light rays are usually emitted by the light source at an angle of more than 60°, in particular more than 75°, preferably more than 85°, to a surface normal of the light-guiding film. The reflector structure can be part of a reflector film and / or a reflector grid.

[0058] The reflector structure is typically formed with one or more reflector structure elements in order to redirect the light in the direction of the light-guiding film by refraction of the light, in particular the light component, at the reflector structure elements. The reflector structure elements can each be formed with an elevation and / or depression, in particular a surface of the reflector film or the reflector grid. Light refraction typically occurs at interfaces between the reflector structure elements. It is advantageous if the reflector structure is arranged such that at least one reflector structure element is arranged between each two illuminants. This applies in particular in a plan view of the light source or the respective illuminant. Expediently, in particular in a plan view, the respective illuminant can be enclosed by one or more reflector structure elements.The interfaces can be formed with outer surfaces of the reflector structural elements. It is advantageous if one or more interfaces of the respective reflector structural element are aligned in such a way that the light component is redirected by total internal reflection. This applies in particular to the light component of a light source to which the reactor structural element is assigned.

[0059] It is advantageous if the average height of the reflector structure elements is between 10 pm and 500 pm, in particular between 80 pm and 200 pm. A height typically refers to a distance between a highest point of an elevation and a lowest point of a depression, in particular one adjacent to the elevation. It is particularly advantageous if the average height is less than 80 pm, in particular between 10 pm and 80 pm. The height of the film structure elements is typically measured orthogonally to a longitudinal extent and orthogonally to the main emission direction of the light source, in particular of the respective illuminant, or to the width extent of the light-directing film or film structure.

[0060] It is advantageous if, particularly in plan view, the reflector structure elements form an arrangement structure with a plurality of reflector structure elements arranged along a closed line. The arrangement structure can define a plurality of concentric closed lines, wherein reflector structure elements are arranged along the respective line. The reflector structure elements are usually arranged along the respective line, preferably regularly, spaced apart or adjacent to one another. Preferably, the reflector structure elements form a plurality of such arrangement structures. The arrangement structures can be arranged next to one another, in particular in rows. Alternatively or cumulatively, it is advantageous if, particularly in plan view, one or more reflector structure elements form an arrangement structure, wherein the respective reflector structure element of the arrangement structure has a longitudinal axis running along a closed line.A longitudinal extension of the reflector structure element along the longitudinal axis typically forms a self-contained structure. Preferably, the reflector structure elements of the arrangement structure have concentric longitudinal axes, each of which, in particular, runs along a closed line.

[0061] It is advantageous if, particularly in plan view, the closed line forms a perimeter around the light source, in particular around one of the illuminants. Expediently, several illuminants can each be assigned their own arrangement structure, with the respective closed line of the arrangement structure forming a perimeter around the illuminants. In this way, the respective illuminant can be surrounded by one or more self-contained structures formed by reflector structure elements for light deflection.

[0062] It is advantageous if, particularly in plan view, the light source, in particular the respective illuminant, is surrounded by one or more reflector structural elements extending along a circumference around the light source or the illuminant. For this purpose, a reflector structural element can have a longitudinal extension extending along the circumference, or several reflector structural elements can be arranged next to one another in the circumferential direction of the circumference.

[0063] It has proven useful if, in a cross-section through the respective reflector structural element, the respective reflector structural element has a tapered or widening outer contour, in particular in the main emission direction or counter to the main emission direction. The main emission direction can refer to a respective illuminant to which the respective reflector element is assigned in order to redirect a portion of the light emitted by the illuminant. The cross-section usually runs orthogonal to the longitudinal axis of the reflector structural element and / or parallel to the main emission direction of the respective illuminant. The outer contour refers in particular to a segment of the reflector structural element running along the closed line. The outer contour can be substantially triangular or trapezoidal.The outer contour can expediently have a curved head region on a side facing the film structure of the light-guiding film and / or on a side facing away from the film structure of the light-guiding film. It is advantageous if the outer contour is formed with two outer contour flanks opposite one another on the reflector structure element, wherein the outer contour flanks are preferably aligned convergently or divergingly with respect to one another. The outer contour flanks can be flat or, in particular, concavely or convexly curved. As a rule, both outer contour flanks are concave or both outer contour flanks are convex. The outer contour flanks can be connected to one another in a head region of the reflector structure element with a straight or curved head contour line, in particular adjoin one another, or the outer contour flanks can adjoin one another directly in the head region.

[0064] It is advantageous if the reflector film has through-openings, wherein in a plan view the reflector film is arranged such that illuminants are located within, in particular in a center, of the through-openings. In this case, at least one illuminant can expediently be located within, in particular substantially in the center, of the respective through-opening. As a result, light emitted by the illuminants in the light emission direction, in particular the main emission direction, can reach the light-directing film through the through-openings. The through-openings usually extend entirely through the reflector film. It is advantageous if, in a plan view, different illuminants are located in different through-openings. Expediently, each illuminant can be assigned its own through-opening.The through openings can be arranged and shaped such that the reflector foil represents a reflector grid formed with, in particular by, the reflector structure elements.

[0065] The reflector structure, in particular reflector film, can be arranged in an arrangement surface, in particular arrangement plane, of the illuminants and / or above the illuminants in the main emission direction. It can be practical if the reflector film is arranged in the main emission direction between the light source, in particular the illuminants, and the light-directing film. The reflector film can be spaced apart from the light source, in particular the illuminants, and / or the light-directing film in the main emission direction. It can be advantageous if the reflector film and the light-directing film are connected to one another, in particular mechanically. In particular, the reflector film and the light-directing film can form a monolithic body. The reflector structure can be formed with a surface of the reflector film. The surface can face the light source, in particular the illuminants, or face away from them.The respective reflector structure element can be implemented with, in particular, an elevation and / or depression of the surface of the reflector film. It is advantageous if the reflector structure is formed as part of the light-guiding film. For example, the reflector structure can be formed with a first surface of the light-guiding film facing the light source, in particular the illuminants, and the film structure can be formed with a second surface of the light-guiding film facing away from the light source, in particular the illuminants. The respective reflector structure element can be implemented with, in particular, an elevation and / or depression of the first surface. The first surface and the second surface are usually opposite one another on the light-guiding film.

[0066] Further features, advantages, and effects of the invention will become apparent from the following description of an exemplary embodiment. The drawings, to which reference is made, show:

[0067] Fig. 1 is a schematic flow diagram of a method for producing a structural film;

[0068] Fig. 2 is a schematic representation of an embossing of an embossed structure into an embossed body with a profile of a profiled object;

[0069] Fig. 3 to Fig. 6 are schematic representations of structural elements in a cross-section; Fig. 7 is a schematic representation of a structural film;

[0070] Fig. 8 is a schematic representation of a structural film in a cross section; Fig. 9 is a schematic representation of a structural element in a cross section.

[0071] Fig. 1 shows a schematic flow diagram of a method 1 for producing a structural film 2. It is provided that a profile 5 of a profiled object 3 is generated using an additive manufacturing method, in particular a ceramic 3D printing method, designated as A in Fig. 1. The profile 5 is preferably formed with, in particular from, ceramic. Subsequently, an embossed structure 6 is embossed into an embossed body 4 using the profile 5, designated as B in Fig. 1. The embossed structure 6 is preferably formed with, in particular from, metal. Subsequently, a film structure 9 is embossed into a film material layer using the embossed structure 6 in order to form the structural film 2, designated as C in Fig. 1. It is preferred if the film material layer is liquid or partially liquid when the film structure 9 is embossed into it and cools down or is actively cooled during the embossing, so that the film material layer forms a film orsolidifies into such a film. Alternatively or cumulatively, the film material layer can be solid or form a film before the film structure 9 is embossed into it.

[0072] By combining the formation of the profile 5 with an additive manufacturing process and the creation of the embossed structure 6 by embossing with the profile 5, a robust embossed structure 6 with high precision and / or a complex shape and thus a correspondingly advantageous film structure 9 can be realized. The structural film 2 is preferably a light-directing film in order to effect a change in the luminous intensity distribution of a light from a light source with the film structure 9.

[0073] Fig. 2 schematically shows a state of embossing an embossed structure 6 into an embossing body 4 with a profile 5 of a profiled object 3. In particular, the embossed structure 6 of method 1 of Fig. 1 can be implemented in this way. The embossing body 4 is designed as an embossing roller. The profiled object 3 is designed as a profiled roller. The profile 5 is designed as part of a profiled roller shell 7 of the profiled object 3. The profiled object 3 and the embossed body 4 are rolled onto one another in order to emboss an embossed structure 6 corresponding to the profile 5 into an embossing roller shell 8 of the embossing body 4 with the profile 5. The profiled object 3 and the embossed body 4 are each mounted so as to be rotatable about a rotation axis, so that the embossed structure 6 can be embossed into the embossed body 4 with the profile 5 rotating while the profiled object 3 rotates and while the embossed body 4 rotates.The profile 5 is usually embossed essentially circumferentially into the embossing roll shell 8. A longitudinal extent of the profile roll shell 7 or of the profile 5 is usually smaller than a longitudinal extent of the embossing roll shell 8. The longitudinal extents are usually measured parallel to the respective rotation axis. The profile object 3 or profile roll shell 7 is usually displaced relative to the embossing roll shell 8 in a displacement direction parallel to the rotation axis of the profile object 3 in order to emboss the embossed structure 6 with the profile 5 in different areas of the embossing roll shell 8 along an extent of the embossing roll shell 8 in the displacement direction. The profile 5 or the embossed structure 6 or the film structure 9 are each formed with structural elements 10 designed as elevations and / or depressions.The structural elements 10 of the embossed structure 6 are generally designed to correspond in shape to the structural elements 10 of the profile 5, usually as a negative image of the latter. The structural elements 10 of the foil structure 9 are generally designed to correspond in shape to the structural elements of the embossed structure 6, usually as a negative image of the latter.

[0074] For a light-guiding film, it is advantageous if the structural elements 10 of the light-guiding film are spaced apart from one another, usually with an average spacing of the structural elements 10 of 5 pm to 200 pm. As a rule, several structural elements 10 are provided, wherein the respective structural element 10 has a surface segment 11 with a shape of a portion of an ellipsoid cut off by a cutting plane 14. The ellipsoid can be an ellipsoid of revolution, in particular a sphere. Typically, the cutting plane 14 orthogonally intersects one of the semi-axes 13 of the ellipsoid. Depending on the distance at which the cutting plane 14 intersects the semi-axis 13 from the center of the ellipsoid, the luminous intensity distribution or glare-reduction properties of light redirected by the film structural elements 10 can be varied.The section is typically arranged such that the semi-axis is parallel to a height of the structural element 10 or the light-directing foil. The structural elements 10 of the profile 5 or the embossed structure 6 are typically configured in a similar manner.

[0075] In Fig. 3 to Fig. 6, various structural elements 10 are shown schematically in a cross-section. The film structure 9 can advantageously be formed with such structural elements 10. The respective surface segment 11 is implemented in the form of a section of an ellipsoid, exemplarily designed as a sphere, cut off by a cutting plane 14. In the structural element 10 of Fig. 3, the cutting plane 14 is orthogonal to the semi-axis 13, wherein the cutting plane 14 runs through the center of the ellipsoid. The surface segment 11 is arranged on a cylindrical surface section 12 of the structural element 10. This makes it possible to achieve a particularly defined luminous intensity distribution. Fig. 4 shows a structural element 10 which is designed corresponding to the structural element 10 of Fig. 3, but without the cylindrical surface section 12. An implementation according to Fig. 3 and Fig. 4 enables a particularly high glare reduction value.In the structural element 10 of Fig. 5, the cutting plane 14 is orthogonal to the semi-axis 13, with the cutting plane 14 intersecting the semi-axis 13 starting from the center of the ellipsoid at a first third of the length of the semi-axis 13. This makes it possible to achieve a good glare control value with a broad luminous intensity distribution. In the structural element 10 of Fig. 6, the cutting plane 14 is orthogonal to the semi-axis 13, with the cutting plane 14 intersecting the semi-axis 13 starting from the center of the ellipsoid at a second third of the length of the semi-axis 13. This makes it possible to achieve a small glare control value and a particularly broad luminous intensity distribution. The respective structural element 10 can be designed as an elevation or depression of the film material layer or film or structural film 2.

[0076] Fig. 7 schematically shows a structural film 2, which is designed in particular as a light-directing film, in a plan view or viewed parallel to a height of the structural film 2. The structural film 2 can be designed as described for Fig. 1 to Fig. 6. The structural film 2 or its film structure 9 has structural elements 10 arranged in rows. Preferably, a plurality of rows of structural elements 10 are provided, oriented in an arrangement direction, wherein the rows are aligned parallel to one another. It has proven useful if immediately adjacent rows are arranged offset from one another in the direction of arrangement, preferably essentially by half the average length in the arrangement direction of a structural element 10 of the row. The film structure 9 of the structural film 2 or the respective structural element 10 can be designed as described for Fig. 1 to Fig.6, in particular having a corresponding surface segment 11. The respective structural element 10, in particular its surface segment 11, can be designed as an elevation or depression. If the structural film 2 is a light-directing film of a lighting device, such as a luminaire, it has proven useful if the respective structural element 10 is an elevation. If the structural film 2 is a light-directing film of a solar module, it has proven useful if the respective structural element 2 is a depression.

[0077] Fig. 8 schematically shows a cross-section of a structural film 2, in particular a light-directing film. The structural film 2 is, in particular, the structural film 2 of Fig. 7. The structural film 2 or its film structure 9 has a plurality of structural elements 10, each designed as a recess. The structural film 2 can expediently be designed as a light-directing film as part of a solar module in order to direct sunlight L with the light-directing film 2 or the film structure 9 toward a light conversion element of the solar module. In the deployed state, the film structure 9 can expediently be oriented toward the sun.

[0078] Fig. 9 schematically shows a further structural element 10 in a cross-section. The film structure 9 can advantageously be formed with such structural elements 10. The light-directing film can be formed with several such structural elements 10, as explained above. The structural element 10 has a surface region 16 which forms a surface of revolution, wherein the surface of revolution forms an outer contour 17 in a cross-section along a rotation axis 20 of the surface of revolution, which outer contour is formed by two ellipse segments 19 adjoining one another with a corner 18. The corner 18 is intersected by the rotation axis 20. The two ellipse segments 19 run mirror-symmetrically to one another with respect to the rotation axis 20. It is preferred if the corner 18 forms the highest point of the structural element 10. In particular, the structural film 2 or light-directing film of Fig. 7 and Fig.8 can be formed in an analogous manner with such structural elements 10.

[0079] If, for the production of a light-directing film with a profile 5 of a profiled object 3, such as a profile roller, which profile 5 is formed using an additive manufacturing process, an embossed structure 6 is embossed into an embossing body 4, such as an embossing roller, after which a film structure 9 is embossed into a film material layer or film using the embossed structure 6, a high accuracy and / or complex shape of the film structure 9 can be implemented.

Claims

Patent claims 1. Method (1) for producing a structural film (2), preferably a light-directing film, wherein a film structure (9) corresponding to the embossed structure (6) is embossed into a film material layer using an embossed structure (6) of an embossing body (4), in particular an embossing roller, characterized in that to form the embossed structure (6), the embossed structure (6) is embossed into the embossed body (4) with a profile (5) of a profiled object (3), wherein the profile (5) is generated using an additive manufacturing process, in particular a ceramic 3D printing process.

2. Method (1) according to claim 1, characterized in that the profiled article (3) and / or the embossed body (4) are cylindrical and are rolled on one another in order to emboss the embossed structure (6) into the embossed body (4) with the profile (5).

3. Method (1) according to claim 1 or 2, characterized in that the embossed structure (6) is formed with a metal material of the embossed body (4), wherein during and / or after a deformation of the metal material by means of the profile (5) a hardness of the embossed structure (6) is increased, preferably by plastic deformation of the metal material and / or by metallurgical hardening of the metal material and / or by applying a hardening layer to the metal material.

4. Method (1) according to one of claims 1 to 3, characterized in that the profile (5) is formed with structural elements (10) designed as elevations and / or as depressions, wherein an average height of the structural elements (10) is from 10 pm to 500 pm, in particular from 80 pm to 200 pm.

5. Method (1) according to one of claims 1 to 4, characterized in that the profile (5) is formed with structural elements (10) designed as elevations and / or as depressions, wherein an average distance of the structural elements (10) is from 5 pm to 200 pm, in particular from 5 pm to 80 pm.

6. Method (1) according to one of claims 1 to 5, characterized in that the profile is formed with structural elements (10) designed as elevations and / or as depressions, wherein at least one of the structural elements (10) has a surface segment (11) with a shape of a part of an ellipsoid cut off by a cutting plane (14).

7. Method (1) according to claim 6, characterized in that the surface segment (11) is arranged on a cylindrical surface section (12) of the structural element (10).

8. Method (1) according to one of claims 1 to 7, characterized in that a film structure (9) is embossed on one side or both sides of the film material layer.

9. Method (1) according to one of claims 1 to 8, characterized in that the film material layer is curved along a longitudinal extent and / or along a width extent of the film material layer.

10. Method (1) for producing a lighting device, wherein the lighting device has a light-directing film for changing a luminous intensity distribution of a light source, characterized in that the light-directing film is produced by a method (1) according to one of claims 1 to 9.

11. Method (1) for producing a solar module for converting solar energy, wherein the solar module has at least one light conversion element, such as a solar cell, and a light-directing film for changing a light intensity distribution of sunlight in order to direct sunlight with the light-directing film in the direction of the at least one light conversion element, characterized in that the light-directing film is produced by a method (1) according to one of claims 1 to 10.

12. Device for producing a structural film (2), in particular with a method (1) according to one of claims 1 to 11, characterized in that the device has a profiled article (3) with a profile (5) in order to emboss an embossed structure (6) into an embossed body (4) with the profile (5) in order to emboss the embossed structure (6) a foil structure (9) corresponding to the embossed structure (6) into a foil material layer, whereby the profile (5) is provided with an additive manufacturing processes, especially ceramic 3D printing processes.

13. Device according to claim 12, characterized in that the profiled object (3) is a profile roller and / or the embossing body (4) is an embossing roller in order to emboss an embossed structure (6) into the embossing body (4) by rolling the profiled object (3) and the embossing body (4) on each other with the profile (5).

14. Light-directing film, which is produced in particular using a method (1) according to one of claims 1 to 9, for changing a luminous intensity distribution of a light emitted by a light source, wherein the light-directing film has a film material layer with a film structure (9) in order to change a direction of a light from the light source incident on the film structure (9), wherein the film structure (9) is formed with structural elements (10) designed as elevations and / or depressions, characterized in that at least one of the structural elements (10) has a surface segment (11) with a shape of a part of an ellipsoid cut off by a cutting plane (14).

15. Light-directing film according to claim 14, characterized in that the structural elements (10) are spaced apart from one another, an average spacing of the structural elements (10) being from 5 pm to 200 pm, in particular from 5 pm to 80 pm.

Images