DE102019125640A1 - Optical element - Google Patents

Abstract

The present invention relates to an optical element (1) for a flat lamp, having a flat light coupling side for introducing light into the optical element (1) and a flat light coupling side (2) opposite the flat light coupling side for emitting the light introduced via the light coupling side. The light coupling-out side (2) has: a first zone (3) for diffusely scattering light output of a first part of the light introduced via the light coupling-in side, and several second zones (4) provided in the first zone (3) for light output of a second part of the light input side light introduced on the light coupling side in such a way that the light emitted via the second zones (4) is at least partially directed in a defined manner. The invention also relates to a flat lamp having such an optical element (1).

Description

Field of the invention

The present invention relates to an optical element and a flat lamp having such an optical element.

background

Flat lights are usually used for large-area lighting. For example, such luminaires are used to illuminate rooms such as offices. In addition, such lights can also be provided for illuminating workplaces provided in rooms. The light output by the luminaire should take place in such a way that the light is “glare-free” or “glare-free”, in order not to dazzle people on the one hand and to avoid disturbing reflections on vertical surfaces on the other. “Glare-free” or “glare-free” means that the so-called luminance drops below a predetermined limit value above a certain limit angle with respect to the vertical or surface normal of the flat lamp. A light emission at an angle that is too flat would, however, result in particular in the glare of people who are looking at the luminaire at an angle from below.

Due to the flat design of the lamp, the lamp can be arranged in a particularly compact manner; the luminaire appears flat or essentially two-dimensional to a viewer. For an advantageous appearance of the luminaire or of the mounting area provided for the luminaire, such as a ceiling, it may be desirable for the luminaire to appear three-dimensional. A three-dimensional appearance of the luminaire can be produced, for example, in that the luminaire is designed three-dimensionally, that is to say does not have an essentially flat design; however, this in turn means that the luminaire takes up a relatively large amount of space and is therefore not very compact. In addition, a flat design of the lamp is more suitable for an anti-glare effect when emitting light.

The present invention thus sets itself the task of overcoming the disadvantages mentioned above. That is, it is particularly an object of the present invention to provide a three-dimensional effect of a lamp while the lamp is compact and has a glare-reducing effect.

These and other objects, which will be mentioned on reading the following description or which can be recognized by the person skilled in the art, are achieved with the subject matter of the independent claims. Advantageous further developments are the subject of the dependent claims which refer back to them.

Detailed description of the invention

According to a first aspect, the invention relates to an optical element for a flat lamp. The optical element has a planar light coupling-in side for introducing light into the optical element and a planar light coupling-out side opposite the planar light coupling-in side for emitting the light introduced via the light coupling-in side. The light outcoupling side has: a first zone for diffusely scattering light output of a first part of the light introduced via the light injection side, and several second zones provided in the first zone for light output of a second part of the light introduced via the light injection side such that the light introduced via the second zones emitted light is at least partially defined (aligned), that is preferably not or is refracted in a defined manner.

A “partially defined directed light emission” is understood to mean that the or at least the corresponding part of the light emitted via the second zones is, in particular, not diffusely scattered. The light beams emitted from the second zones accordingly have defined and preferably different and / or the same directions. In particular, the light passing through the optical element at least in the mentioned part of the second zones should therefore not be refracted or refracted in a defined manner. For example, in a case in which the light coupling-in side and the light coupling-out side of said part of the second zone are aligned parallel to one another, light rays incident perpendicularly are not refracted. In this part of the second zone, when the light input side and light output side are not parallel to one another and / or when the light rays incline at an angle, a defined refraction of light is preferably effected; which differs from a mostly undefined light scattering.

The diffusely scattering light output via the first zone provides in particular the (defined) anti-glare effect of the optical element. The light output via the second zones, which is essentially directed in a defined manner (i.e. in particular not or defined refracted; therefore not or defined deflected) and thus in particular not diffusely scattering, causes light output via these second zones that is less glare-free or not glare-free is compared to the light output over the first zone. That is to say, in particular for viewing angles for which the first zone has lower luminance levels in order to prevent glare, the second zones each have higher luminance levels in order to achieve a desired glare or (defined) brilliance.

Due to the first zone and the diffusely scattering light output, the optical element retains its glare-free effect - for use in offices, for example - while the brilliance brought about by the second zones makes the optical element and thus, for example, a flat luminaire provided with the optical element appear three-dimensional leaves. The flat optical element or the flat lamp with this optical element thus appears three-dimensional without the optical element or the lamp having to be (additionally) designed three-dimensionally.

Each of the second zones can be delimited from the first zone by a defined shape. In this way, in particular, a defined brilliance can be generated, which makes the optical element appear three-dimensional in a particularly advantageous manner.

Each of the second zones can be delimited from the first zone by a circular, elliptical and / or polygonal (for example hexagonal), in particular essentially hexagonal shape. In general, the second zones are not limited to any particular shape. For example, the second zones can have different shapes; alternatively, it is also conceivable that the second zones have identical shapes.

Each of the second zones can have a size such as, for example, an area delimited by the respective shape. For example, the second zones with different sizes are provided in the first zone. A three-dimensional effect of the optical element can thus be generated in a particularly advantageous manner.

As the distance from an inner region of the optical element increases, second zones with smaller sizes are preferably arranged in the first zone. In this way, an especially macroscopic three-dimensional effect of the optical element can be generated particularly well, since the second zones, which become smaller with increasing distance, create an impression of depth and thus make the essentially two-dimensional light coupling-out side appear in the form of a three-dimensional shape such as a sphere.

The size is preferably a circumference, this circumference particularly preferably being in a range from 5 mm to 35 mm, for example in a range from 10 mm to 30 mm. For example, it can be provided that second zones, which are particularly close to said inner area and particularly preferably directly opposite this inner area, i.e. the innermost second zones, have a circumference of essentially 30 mm, whereas the second zones furthest away from the inner area or the outermost second zones, that is to say in particular the second zones directly opposite the outer boundary of the first zone, have a circumference of essentially 10 mm. Alternatively, the size can also be a scope, the aforementioned values or value ranges then preferably also applying to the scope.

According to one example, the distance between adjacent second zones can become larger with increasing distance from one or the inner region. This is of particular benefit to the three-dimensional effect produced by the optical element. The increasing distance between adjacent second zones can be due, for example, to the fact that the second zones become smaller with increasing distance.

The inner region of the optical element can be a center of the optical element. For example, the center is central with respect to the width and / or height of the optical element; the width and height are each seen in a plan view, that is to say in the direction of the surface normal of the planar light coupling-out side, so that the depth corresponds to the thickness of the optical element.

The second zones can be arranged preferably evenly distributed over at least a part and preferably over the entire area of the first zone. This brings about a particularly advantageous (macroscopic) three-dimensional appearance of the optical element.

The second zones can each have at least one light outcoupling structure. The at least one light coupling-out structure can be designed in such a way that the second zones are suitable for influencing the second part of the light introduced via the light coupling-in side in a non-diffusely scattering manner and thus emitting it directly in a defined manner. It can thus be effected in a particularly simple manner that the second zones emit the second part of the light introduced via the light coupling side in a defined direction or, in particular, do not scatter it diffusely.

Alternatively or additionally, it can be provided that the at least one light outcoupling structure for emitting light in a defined direction is designed in such a way that the second zones are suitable for emitting the second part of the light introduced via the light coupling side in defined directions. By the defined directions of the light emission with the second zones and their Light outcoupling structures can produce a particularly advantageous luminance distribution and thus (dynamic) brilliance, so that a particularly advantageous three-dimensional appearance of the optical element can thereby be produced.

The second zones can each have a plurality of light outcoupling structures. The multiple light outcoupling structures can be designed differently or identically. The plurality of light outcoupling structures are preferably distributed (arranged) uniformly over the respective second zone, for example corresponding to the shape of the respective second zone. In other words, the light outcoupling structures, for example at least the outermost light outcoupling structures in each case, can span a shape which corresponds to the shape of the respective second zone.

The at least one light outcoupling structure can be clearly embodied. The (glass) clear design makes it particularly easy to ensure that the light emitted via the second zones is not diffusely scattered in order to thus provide the three-dimensional appearance of the optical element.

The at least one light outcoupling structure can be circular and / or point-shaped. In the case of a plurality of light outcoupling structures, each provided circular and / or punctiform, in the respective second zone, the respective second zone is then preferably formed in a circular and / or punctiform spotted manner. The circular and / or point-like design of the at least one light coupling-out structure results in a particularly advantageous three-dimensional appearance of the optical element.

The at least one light outcoupling structure can be a clear region corresponding to the shape of the respective second zone and preferably encircling it in a closed manner, this region preferably surrounding the respective second zone. In other words, the at least one light coupling-out structure can have a ring shape corresponding to the respective second zone. This shape of the at least one light outcoupling structure makes it possible to provide a particularly advantageous three-dimensional appearance of the optical element.

The at least one light outcoupling structure can be clear and essentially completely cover the respective second zone. In other words, the respective second zone can consist of the (single) clear light outcoupling structure. Accordingly, the at least one light outcoupling structure can be provided particularly easily with respect to the respective second zone, while the light outcoupling structures, provided by the plurality of second zones, produce a particularly advantageous three-dimensional appearance of the optical element.

The at least one light outcoupling structure can have a plurality of preferably adjoining triangular light outcoupling structures, viewed in the direction of the surface normal of the flat light outcoupling side of the optical element. The triangular configuration of the light decoupling structure is particularly preferred for the emission of light in the defined directions; the three-dimensional appearance of the optical element can thereby be produced particularly well.

In one example, the surface normals of the triangular light outcoupling structures can be differently aligned with respect to the flat light outcoupling side and in particular differently in at least six different directions, so that the different alignments of the triangular light outcoupling structures can emit light from the light outcoupling structures in the different, defined directions. Due to the different orientations of the triangular light outcoupling structures, the defined directions of the light output can be set particularly easily. In addition, the result is a particularly advantageous appearance of the second zones, since the second zones appear different to a viewer due to the different directions of the light emission depending on the viewing angle; that is, the appearance of the light coupling-out side changes depending on the viewing angle.

The angle included between two surface normals of differently oriented triangular light output structures, viewed in the direction of the surface normal of the surface normal light output side of the optical element, is, for example, 60 °, 120 °, 180 °, 240 ° or 300 °. This angle corresponds, for example, to different viewing directions with respect to the optical element. A particularly advantageous viewing angle-dependent brilliance of the optical element is thus generated, which gives the optical element a particularly advantageous three-dimensional appearance.

The triangular light outcoupling structures can be formed by sawtooth-like light outcoupling structures (in particular prisms =. “Sawtooth-like” is understood to mean in particular a shape that is that of a pyramid with at least one triangular side surface corresponds to. These sawtooth-like light outcoupling structures are preferably arranged in an undefined manner in order to provide the differently oriented surface normals of the triangular light outcoupling structures. This undefined or chaotic arrangement of the sawtooth-like light coupling-out structures results in a particularly advantageous appearance of the second zones for effecting the three-dimensional appearance of the optical element.

The sawtooth-like light outcoupling structures can each have a base surface and a lateral surface with a side surface, that is to say, in particular, be designed in the manner of a pyramid. The side surfaces of the sawtooth-like light outcoupling structures are the triangular light outcoupling structures. In this way, the normals to the surface of the triangular light outcoupling structures can be provided in a particularly simple manner.

The plurality of triangular light outcoupling structures can essentially completely cover the respective second zone. This results in a particularly good three-dimensional appearance of the optical element.

Each of the light outcoupling structures can have a width or a diameter in the range from 0.1 mm to 2 mm, preferably in the range from 0.1 to 1 mm, wherein the width or the diameter can also be essentially 1.5 mm. Alternatively or additionally, each of the light outcoupling structures can have a circumference in the range from 1 mm to 5 mm. These values are particularly preferred in order to provide an optical element that provides an anti-glare effect but at the same time appears three-dimensional. For example, each of the light outcoupling structures can also have a circumference, in which case the aforementioned values or value ranges of the circumference preferably apply to the circumference of the respective light outcoupling structure.

A distance between adjacent light outcoupling structures of the respective second zone can be in a range from 0.5 mm to 2 mm. The light outcoupling structures of the respective second zone can therefore be provided relatively close to one another in order to bring about the advantageous appearance of the optical element brought about by these light outcoupling structures.

A distance can be provided between the light outcoupling structure and a delimitation or shape which delimits the respective second zone from the first zone. The desired three-dimensional light effect for the advantageous appearance of the optical element can thus be generated particularly well. This distance is preferably at least 3 mm.

Each of the second zones can at least partially have a Fresnel structure and / or a microstructure film in areas in which no light coupling-out structure is provided. In other words, these areas can be provided for diffuse light emission, so that the second zones emit light that is partly diffusely scattered and partly not diffusely scattered.

The optical element can have an edge delimiting the optical element and the light coupling-out side, preferably closed all round, the edge also delimiting the first zone, preferably closed all round. In other words, the front side of the optical element is, for example, the flat light outcoupling side, the front side or light outcoupling side consisting of the first zone and the second zones and, if present, of the third zone or the inner area described below. This has the particularly advantageous effect that the optical element produces an anti-glare effect and at the same time appears three-dimensional, in particular due to the second zones.

The first zone can preferably have microscopic Fresnel structures for diffusely scattering light emission by means of the first zone. A particularly good anti-glare effect can thereby be provided. In addition, the microscopic Fresnel structures are so small that they can hardly be seen by the human eye. In one example, the first zone is formed by a microstructure film for diffusely scattering light emission by means of the first zone.

The first zone can also have a third zone for emitting the light emitted by a secondary illuminant. The secondary means can be, for example, an emergency light. The secondary illuminant or the emergency light is preferably provided in such a way that this or these emit light when the illuminant for the light emission via the first and second zone (primary illuminant) does not emit or can emit any light, for example because an electrical supply to the Primary illuminant is not available. For example, the unavailable electrical supply can be recognized by a control device which then controls the secondary illuminant for emitting light in a corresponding manner.

The third zone is preferably clear. Good visibility of the light emitted by the secondary illuminant can thus be ensured for an observer.

The third zone is preferably designed as a recess for receiving the secondary illuminant. The third zone and the secondary illuminant can thus be provided in a simple manner relative to one another, for example in that the recess positions and / or aligns the secondary illuminant in a defined manner in the third zone.

The third zone can be provided in one or the (above-mentioned) inner region of the optical element. This ensures particularly good visibility of the light emitted by the secondary illuminant, in particular in such a way that the aforementioned glare control of the light via the first zone and the effect of the three-dimensional appearance of the optical element via the second zones are little or not influenced.

The optical element is preferably made from a thin-walled material such as a film, for example. This results in a particularly compact and easy to manufacture structure of the optical element. In particular, such an optical element has only one thickness, namely the material thickness of the thin-walled material or the film.

According to a second aspect, the invention relates to a flat lamp. The flat lamp has a flat light guide with a flat light coupling-out side for emitting light introduced into the light guide. The luminaire also has an optical element as described above, wherein the flat light coupling side of the optical element is in preferably flat contact with the flat light output side of the light guide, so that light emitted by the light guide via the light output side into the optical element via the flat light input side of the optical element Element can be initiated.

The above-described designs and advantages with regard to the optical element apply analogously to the flat lamp. That is, the optical element has the effect, in particular, that the luminaire, which is actually essentially two-dimensional, has a three-dimensional appearance, namely essentially only through the light effect caused by the first zone and the multiple second zones of the optical element. The optical element preferably covers the flat light coupling-out side of the light guide over the entire surface.

Figure list

• 1 eine Draufsicht eines Ausführungsbeispiels eines erfindungsgemäßen optischen Elements;
• 2 eine Draufsicht einer zweiten Zone des in 1 gezeigten optischen Elements gemäß einer ersten Ausführungsform;
• 3 eine Draufsicht einer zweiten Zone des in 1 gezeigten optischen Elements gemäß einer zweiten Ausführungsform;
• 4 eine Draufsicht einer zweiten Zone des in 1 gezeigten optischen Elements gemäß einer dritten Ausführungsform;
• 5 eine Draufsicht einer zweiten Zone des in 1 gezeigten optischen Elements gemäß einer vierten Ausführungsform;
• 6 eine Detailansicht (Draufsicht), welche einen Ausschnitt der Lichtauskopplungsstrukturen der in 5 gezeigten zweiten Zone vergrößert darstellt; und
• 7 eine perspektivische Ansicht einer sägezahnartigen Lichtauskopplungsstruktur zur Bildung der in den 5 und 6 gezeigten Lichtauskopplungsstrukturen.

A detailed description of the figures is given below. Show in the figures

• 1 a plan view of an embodiment of an optical element according to the invention;
• 2 a plan view of a second zone of the in 1 shown optical element according to a first embodiment;
• 3rd a plan view of a second zone of the in 1 shown optical element according to a second embodiment;
• 4th a plan view of a second zone of the in 1 shown optical element according to a third embodiment;
• 5 a plan view of a second zone of the in 1 shown optical element according to a fourth embodiment;
• 6th a detailed view (top view), which shows a section of the light decoupling structures of the in 5 shows the second zone shown enlarged; and
• 7th a perspective view of a sawtooth-like light decoupling structure for forming the in FIGS 5 and 6th light outcoupling structures shown.

The 1 leaves an embodiment of an optical element according to the invention 1 detect. The optical element 1 has a flat light coupling side for introducing light into the optical element 1 on. The optical element 1 furthermore has a planar light coupling-out side opposite the planar light coupling-in side 2 to emit the light introduced via the light coupling side. Since the 1 a top view of the optical element 1 is - that is, a view in the direction of the surface normal of the surface light coupling-out side 2 - the flat light coupling side is not recognizable. In general, the optical element 1 one in the 1 recognizable front side and one facing away from the front side and thus in the 1 undetectable rear side, with the front side of the optical element 1 the light extraction side 2 has and preferably consists of this; the back of the optical element 1 preferably has the light coupling side and particularly preferably consists of this.

The optical element 1 is, at least seen in plan view, not limited to a specific shape. That is, a the optical element 1 and preferably the flat light coupling-out side 2 (closed all round) delimiting edge is not restricted to a specific shape. Like in the 1 recognizable, this edge can, for example, have a rectangular shape. However, it is also conceivable that the optical element 1 delimiting edge has a square, circular, elliptical and / or polygonal shape. in the In general, the optical element can 1 or its edge have a shape that of the respective flat lamp with which the optical element 1 is used, corresponds.

This is done via the flat light coupling side into the optical element 1 The light introduced is preferably the light emitted by a light source such as an LED, for example. The light emitted by the illuminant can enter the optical element directly via the light coupling side 1 arrive or indirectly, for example by means of reflection; this indirect light introduction or reflection can take place, for example, through a flat luminaire as described below or through a light guide of such a luminaire. The optical element 1 is therefore preferably intended for a flat lamp.

Like in the 1 recognizable, has the light coupling-out side 2 a first zone 3rd for diffusely scattering light emission of a first part of the light introduced via the light coupling side. It is preferred if the light coupling-out side 2 a single first zone 3rd having. That about the first zone 3rd The light emitted is preferably used for preferably large-area illumination, for example a workstation or a room such as an office room. This from the first zone 3rd The light emitted should be glare-free or emitted without glare as much as possible. Because of this, the first zone is 3rd designed to diffusely scatter the first part of the light introduced via the light coupling side and thus essentially to glare free. This means that above a certain critical angle with respect to the vertical of the optical element 1 - So with respect to the surface normal of the surface light coupling-out side 2 or with respect to the surface normals of the plane of the drawing 1 the so-called luminance drops below a predetermined limit value, so that above this specific limit angle, in particular, glare of people is prevented or at least reduced. In other words is through the first zone 3rd that through the optical element 1 The UGR value caused is improved, i.e. the UGR value is in particular less than 22, preferably less than 20. The UGR value evaluates the glare from a luminaire, the lower the UGR value, the lower the ( psychological) glare.

So the first zone 3rd emits the first part of the light introduced via the light coupling side in a diffusely scattering manner, it is preferred if the first zone 3rd has diffusely scattering structures. These diffusely scattering structures can have scattering particles and / or other regular or irregular structures, for example. For example, the first zone 3rd microscopic Fresnel structures for diffusely scattering light emission by means of the first zone 3rd exhibit. The first zone 3rd can in particular by means of a microstructure film for diffusely scattering light emission by means of the first zone 3rd be educated. A particularly preferred film for diffusely scattering or glare-free emission of light by means of the first zone 3rd is known under the trade name G-GH85 from bright view technologies.

The first zone 3rd is not restricted to a specific (external) shape or contour. It is preferred if the the optical element 1 and the light extraction side 2 preferably a circumferentially closed edge delimiting the first zone as well 3rd preferably limited circumferentially closed. As the 1 reveals is the (outer) boundary of the first zone 3rd corresponding to the (outer) limitation of the optical element 1 or the light output side 2 formed, so for example rectangular or square, circular, elliptical and / or polygonal.

The light extraction side 3rd also has several in the first zone 3rd designated second zones 4th on. For the sake of clarity, the 1 only for one of the second zones 4th indicate the reference number. The second zones 4th are provided to emit the light of a second part of the light introduced via the light coupling side. That is, that in the optical element 1 Light introduced via the light coupling side preferably consists of only two parts, the first part of this introduced light - as described above - via the first zone 3rd is emitted, and wherein the second part of this introduced light via the second zones 4th from the optical element 1 is delivered. Most of the light emitted by the optical element 1 preferably forms the first part of the in the optical element 1 introduced light.

The second zones 4th emit the second part of the light introduced via the light coupling side in such a way that it passes through the second zones 4th emitted light is at least partially directed in a defined manner; consequently therefore preferably in particular not broken or broken in a defined manner or deflected or deflected in a defined manner and thus in particular not diffuse scattered. Thus, compared to the light output via the first zone 3rd produces a lower glare reduction effect of the light, so that an advantageous three-dimensional appearance of the optical element 1 is generated, although the light outcoupling side 2 of the optical element 1 is essentially two-dimensional or flat. This means that the majority of the light output is via the light coupling-out side 2 of the optical element 1 continues via the first zone 3rd ; the optical element 1 is basically intended for diffuse light emission. One sufficient Glare-free light emission is thus guaranteed. The remaining or lower proportion of the light output via the light coupling-out side 2 of the optical element 1 then preferably takes place at least over the second zones 4th . This part of the light output via the second zones 4th is then deliberately not or less glare-free, which creates a deliberate glare or brilliance. The optical element 1 or the light extraction side 2 appears due to the emission of light via the second zones 4th or the brilliance produced in this way is then three-dimensional.

The second zones 4th are not limited to any particular form. However, it is preferred that each of the second zones 4th by a defined shape from the first zone 3rd is delimited. As the 1 to 6th can reveal each of the second zones 4th by a substantially hexagonal shape from the first zone 3rd be demarcated. As can be seen in the figures, the corners of this hexagonal shape are preferably rounded, but can alternatively also be angular. Alternatively or in addition to the hexagonal shape, each of the second zones 4th also by a circular, elliptical and / or (other) polygonal shape of the first zone 3rd be demarcated. For example, it can be provided that the second zones 4th have different shapes, for example a first number of second zones 4th a hexagonal shape and a second number of second zones 4th have a shape different from the hexagonal shape (in particular circular, elliptical, rectangular, square).

Any of the second zones 4th has a size. This size can be, for example, an area bounded by the respective shape, that is to say an area, and / or a circumference and / or a circumference. As the 1 reveals, it is preferred if in the first zone 3rd the second zones 4th with different sizes are provided. Thus, the different sizes alone - i.e. in the 1 with different areas (contents) or perimeters or circles - the impression of a three-dimensional shape is created, which is in the 1 has the shape of a hemisphere, for example, which is preferably centered with respect to the width and / or height of the optical element 1 or light coupling side 2 is provided.

To generate the aforementioned three-dimensional shape, it is preferred if the distance to an interior area increases 5 second zones 4th with smaller sizes in the first zone 3rd are arranged; with increasing distance to the interior 5 so takes the size of the second zones 4th preferred from. In the embodiment according to 1 in particular the extent or circumference of the second zones takes place 4th with increasing distance to the interior 5 from. For example, they face directly to the interior 5 adjacent second zones 4th or those directly to the interior 5 opposite second zones 4th the largest sizes or perimeters, with the second zones 4th with the greatest distance to the interior 5 or that of the boundary of the first zone 3rd directly opposite second zones 4th , so the outermost second zones 4th that have the smallest sizes or scopes. So it can be provided that the periphery of the second zones 4th ranges from 10 mm to 30 mm; those to the interior 5 directly adjacent second zones 4th then preferably have a circumference of essentially 30 mm, said outermost second zones 4th preferably have a circumference of essentially 10 mm. Preferably the size of the second zones increases 4th with increasing distance to the interior 5 linearly.

As the 1 can also be seen, it is preferred if with increasing distance to the interior 5 the distance between adjacent second zones 4th gets bigger. The distance between adjacent second zones 4th becomes larger, for example, by - as previously described - the size of the second zones 4th decreases with increasing distance. For example, the distance between is directly to the interior 5 adjacent second zones 4th one below adjacent second zones 4th minimum distance, whereas the neighboring outermost zones 4th have the greatest spacing among adjacent second zones.

The interior 5 is preferably central with respect to the width and / or the height of the optical element 1 intended. It can thus be provided that the interior 5 a center of the optical element 1 or the light output side 2 is. The interior 5 is not limited to any particular shape. Like in the 1 shown as an example, the interior 5 for example have a rectangular shape. The interior 5 however, it can also have other shapes, for example a square, circular, elliptical and / or (other) polygonal shape. The interior 5 can also be independent of the differently sized second zones 4th be provided.

The second zones 4th are not limited to a specific number. The number of second zones is preferred 4th such that the zones 4th Form a grid shape, the grid shape - so the large number of compared to the first zone 3rd relatively fine second zones 4th - Essentially the three-dimensional appearance or the depth effects of the optical element 1 produce. The second zones 4th can over at least part and preferably over the entire area of the first zone 4th preferably be arranged evenly distributed. For example, the multiple second zones are 4th over more than half the width and / or height of the optical element 1 arranged distributed. For example, the number of the second zones is 4th at least 25 or at least 50 or at least 75 or at least 100. The number of second zones 4th is preferably not more than 300, for example not more than 250 or 200 or 175 or 150 second zones 4th .

The first zone 3rd can be a third zone 6th have, which are preferably in the interior 5 of the optical element 1 is provided. This third zone 6th is preferably designed to be clear and is therefore suitable in principle for non-diffuse light emission. The third zone 6th is not limited to any particular shape. It is preferred if the third zone 6th has a shape that corresponds to the shape of the interior region 5 corresponds to. The interior area is preferred 5 from the third zone 6th . The third zone 6th is preferably provided in order to emit the light emitted by a secondary illuminant, not shown in detail. This secondary illuminant can be, for example, an emergency lamp, which is preferably only operated when a primary illuminant - that is, the illuminant for emitting the light, which is for emitting light by means of the first zone 3rd and the second zones 4th into the optical element 1 is initiated - is not operated or cannot be operated.

The primary illuminant and the secondary illuminant are preferably functionally connected to a control device such as an operating device. The control device is preferably at least set up to recognize whether the primary illuminant is not being operated or cannot be operated, for example because a corresponding electrical energy supply for the primary illuminant is not available; On the basis of this detection, the control device then controls the secondary illuminant in a corresponding manner - that is to say, for example, switches it on to emit light - so that it then passes through the third zone accordingly 6th Can emit light, for example in the form of an emergency light.

The third zone 6th is preferably designed to emit the light emitted by the secondary illuminant directly, that is to say in particular not to scatter it diffusely, in order to ensure good visibility of the light emitted by the secondary illuminant. This can be done in particular by the third zone 6th is clearly formed.

For the simple relative provision of the third zone 6th and the secondary illuminant to each other can be provided that the third zone 6th is designed as a recess for receiving the secondary illuminant. The recess preferably extends over the entire interior area 5 and / or over the entire third zone 6th . The recess can have a depth that is in comparison to the thickness of the optical element 1 is less; The recess is preferably continuous or as a penetration opening in the optical element 1 intended.

As described above, the second are zones 4th each provided over the second zones 4th emitted light at least partially in a defined direction, that is to say preferably not to break it or to break it in a defined manner or to deflect it in a defined manner and thus in particular not to scatter it diffusely. This can be done in different ways, as described below. In the 2 to 4th are first embodiments of the second zones 4th shown. The 5 to 7th show a further or fourth embodiment of a second zone 4th . In the 2 to 7th is only applied to one of the zones 4th of the optical element 1 Referenced; it goes without saying that this description also applies to the other zones 4th of the optical element 1 applies.

The ones in the 2 to 4th illustrated embodiments of the second zones 4th have in particular in common that the second zones 4th in each case at least one light outcoupling structure 20th , 30th , 40 have, wherein the at least one light outcoupling structure 20th , 30th , 40 is designed such that the second zones 4th are suitable for influencing the second part of the light introduced via the light coupling side in a non-diffusely scattering manner and thus emitting it directly in a defined or defined direction. This can be done, for example, by the respective at least one light outcoupling structure 20th , 30th , 40 , 50 clear (crystal clear) is formed. In other examples, the respective at least one light outcoupling structure can also be designed as a through opening in order not to further influence the second part of the light introduced via the light infeed side and thus to emit it in a directly directed manner.

The 2 leaves a first zone 4th with at least one light outcoupling structure 20th recognize according to a first embodiment. It can be seen that the second zone 4th preferably several light outcoupling structures 20th having. These several light outcoupling structures 20th are in each case preferably circular and / or punctiform, so that the respective second zone 4th receives a circular or point-like spotted pattern ("freckle" pattern). The light decoupling structures 20th however, they can each also have other shapes, for example elliptical, polygonal, rectangular, square, etc. shapes.

The light decoupling structures 20th are generally not limited to any particular size. For example, the Light decoupling structures 20th have identical or different sizes. It is preferred if each of the light outcoupling structures 20th has a width or a diameter in the range from 0.1 mm to 2 mm, particularly preferably in the range from 0.1 mm to 1 mm, or wherein the width or the diameter is, for example, essentially 1.5 mm. Alternatively or additionally, each of the light outcoupling structures 20th have a circumference (for example a circular circumference) in the range from 1 mm to 5 mm.

The multiple light extraction structures 20th are not on a specific arrangement with respect to the respective second zone 4th limited. As the 2 can be seen, however, it is preferred if the plurality of light outcoupling structures 20th evenly over the respective zone 4th are distributed, for example the shape of the respective second zone 4th corresponding. Thus, the multiple light outcoupling structures 20th , so at least the outermost light outcoupling structures 20th or that directly of the delimitation of the respective second zone 4th opposite light outcoupling structures 20th , for example, be arranged according to a hexagonal shape, as the respective second zone 4th preferably has a hexagonal shape. Alternatively or additionally it can be provided that - as in the 2 recognizable as an example - the distances between neighboring light outcoupling structures 20th are identical. However, it can also be provided that the distances between adjacent light outcoupling structures are different. It is preferred if there is a distance between adjacent light outcoupling structures 20th of the respective zone 4th is in a range from 0.5 mm to 2 mm. By providing the distances between adjacent light outcoupling structures 20th cover the light outcoupling structures 20th the respective second zones 4th preferably not completely.

It is preferred if a distance between the directly delimiting the respective second zone 4th opposite light outcoupling structures 20th on the one hand and the delimitation of the respective second zone 4th on the other hand is provided. For a particularly good light effect, this distance is preferably at least 3 mm.

The 3rd leaves a second zone 4th with a light decoupling structure 30th recognize according to a second embodiment. It can be seen that the respective second zone 4th preferably only one light outcoupling structure 30th having. The light decoupling structure 30th is clearly designed and one of the shape of the respective second zone 4th corresponding and preferably closed circumferential area. In the 3rd illustrated light decoupling structure 30th is therefore preferably a hexagonal area, for example an annular area in the form of a hexagon. The light decoupling structure 30th in the form of an annular region, however, can also have other shapes, for example a circular, elliptical, polygonal, in particular square or rectangular shape.

The one through the light outcoupling structure 30th The area formed is not based on a specific arrangement with respect to the respective second zone 4th limited. As the 3rd can be seen, it is preferred if the through the light outcoupling structure 30th formed area the respective second zone 4th surrounds and / or with respect to the respective second zone 4th is provided in the middle. In other words, it can be provided that the light outcoupling structure 30th formed area the second zone 4th from the first zone 3rd delimits, so that by the light outcoupling structure 30th formed area the shape of the respective second zones 4th Are defined. That is, the light outcoupling structure 30th or the corresponding area is preferably congruent with the shape of the respective second zone 4th . In other examples, the can through the light outcoupling structure 30th formed area also inside or outside the boundary of the second zone 4th be provided.

The light decoupling structure 30th preferably has a width or thickness; the width of the light outcoupling structure 30th extends transversely to a circumferential direction of the light outcoupling structure 30th , the light outcoupling structure along this circumferential direction 30th extends around the shape of the respective second zone 4th to form corresponding and preferably closed circumferential area. The width of the light outcoupling structure 30th is preferably a constant width along the circumferential direction of the light outcoupling structure 30th . This width is preferably in a range from 0.1 mm to 1 mm, particularly preferably in a range from 0.25 mm to 0.8 mm. The scope or circumference of the light outcoupling structure 30th preferably corresponds to the circumference or circumference of the respective second zone 4th , the periphery of the light outcoupling structure 30th is therefore preferably in a range from 5 mm to 35 mm, for example in a range from 10 mm to 30 mm.

The 4th leaves a second zone 4th with a light decoupling structure 40 recognize according to a third embodiment. The light decoupling structure 40 is clearly formed and covers the respective second zone 4th essentially completely. That is, the second zone 4th has only one light outcoupling structure 40 on, the respective second zone 4th from this light outcoupling structure 40 consists. The light decoupling structure 40 thus also defines the shape of the respective second zone 4th . The size of the light extraction structure 40 essentially corresponds to the size of the respective zone 4th , that is, the perimeter of the Light decoupling structure 40 can preferably be in a range from 5 mm to 35 mm, for example in a range from 10 mm to 30 mm.

In the 5 is a fourth embodiment of the respective second zones 4th shown as an example. In contrast to the ones in the 2 to 4th illustrated embodiments of the second zones 4th or light outcoupling structures 20th , 30th , 40 assigns the in the 5 illustrated embodiment of the zone 4th one or more light outcoupling structures 50 on. Each of the light extraction structures 50 is designed to emit light in a defined direction in such a way that with the plurality of second zones 4th the second part of the light introduced via the light coupling side can be emitted in defined directions. For example, it can be provided that a second zone 4th by means of a light decoupling structure 50 Emits light in a first defined direction and another second zone 4th by means of a light decoupling structure 50 Emits light in a second defined direction, so that the second zones 4th - So here the one and the other second zone 4th - Emit the second part of the light introduced via the light coupling side in (different) defined directions.

As the 5 can be seen, it is preferred if each of the second zones 4th several light outcoupling structures 50 having. Like in the 6th If shown enlarged, it is preferred if in plan view or in the direction of the surface normal of the light coupling-out side 2 of the optical element 1 seen these multiple light outcoupling structures 50 are each triangular. Like in the 6th for a small section of the zone 4th shown, border the triangular light outcoupling structures 50 preferably to each other. The multiple triangular light decoupling structures 50 thus preferably form one of the triangular light outcoupling structures 50 existing mosaic, this mosaic being the respective second zone 4th partially or completely covered. That is to say, preferably cover the plurality of triangular light outcoupling structures 50 the respective second zone 4th only partially or completely. As the 6th can be seen, neighboring light outcoupling structures 50 adjoin each other by the triangular shapes of neighboring light outcoupling structures 50 have a common (triangular) leg. Thus, there is preferably no spacing between adjacent light outcoupling structures 50 .

In the 6th it can be seen that the surface normals N of the respective triangular light outcoupling structures 50 with regard to the flat light coupling-out side 2 can be oriented differently. This is in 6th recognizable by the differently aligned arrows, the directions of the arrows being the components of the respective surface normals projected onto the plane of the drawing N represent. Can be seen in 6th Furthermore, that these different directions (for an unlimited number of light outcoupling structures 50 ) at least and preferably only six different directions (every second zone 4th ) are. In this way, through the different orientations of the triangular light outcoupling structures 50 the light from the triangular light decoupling structures 50 are emitted in the different, defined directions in order to thus generate a particularly advantageous brilliance for bringing about the three-dimensional appearance.

As the 6th can be seen, it is particularly preferred if the in the direction of the surface normal of the surface light coupling-out side 2 of the optical element 1 , i.e. perpendicular to the plane of the drawing 6th seen and between two surface normals N differently aligned triangular light outcoupling structures 50 included angles α is 60 °, 120 °, 180 °, 240 ° or 300 °. In the 6th this angle α is an example of the two triangular light outcoupling structures on the top left 50 shown; the angle α is essentially 60 °. Like in the 6th recognizable, triangular light outcoupling structures can also be recognized 50 be provided so that their surface normals N are directed in the same direction.

The differently oriented surface normals N of the triangular light outcoupling structures 50 can be provided in different ways. One possibility for providing the differently aligned triangular light outcoupling structures 50 is exemplary in 7th for one of the triangular light outcoupling structures 50 shown. In the 7th it can be seen that the triangular light decoupling structures 50 for example through a sawtooth-like or pyramid-like light decoupling structure (prism) 51 can be formed. Several such sawtooth-like light decoupling structures 51 can thus preferably be arranged in an undefined or chaotic manner around the previously described differently oriented surface normals N of the triangular light outcoupling structures 50 provide. The multiple light extraction structures 51 thus form a (prismatic) grating, this grating having a grating constant (period) of approx. 10 µm to 200 µm.

As the 7th can be seen is the sawtooth-like light decoupling structures 51 for the respective triangular light outcoupling structure 50 corresponding to a pyramid or a Sawtooth formed. That is, the sawtooth-like light coupling-out structure 51 has a base area 52 and one different from the base 52 away extending jacket surface 53 on. The outer surface 53 again has at least one side surface 54 on. This side face 54 forms the triangular light decoupling structure 50 . The side face 54 has a certain orientation, that of the surface normal N the respective triangular light outcoupling structure 50 corresponds to; the orientation of the face 54 the sawtooth-like light outcoupling structure is therefore in the 7th also by the surface normal N indicated. The orientation of the face 54 and thus the alignment of the respective triangular light outcoupling structure 50 , i.e. the direction of the surface normal N , is in particular due to the angle 0 between the side face 54 and one of the side face 54 opposite further side surface 55 or by the angle of yet another, the side surfaces 54 , 55 connecting face 56 set. The angle Θ is preferably at least 10 °.

Each of the light extraction structures 50 is not limited to a specific size. For example, each of the triangular light outcoupling structures 50 a width, the width being, for example, the height and / or the length of a leg of the triangle forming the triangular shape. The width is preferably in a range from 0.1 mm to 1 mm. The perimeter of every light outcoupling structure 50 is preferably in a range from 1 mm to 5 mm.

As exemplified in the 2 and 3rd shown, each of the second zones 4th one or more areas 60 have, in which no light decoupling structure 20th , 30th , 50 is provided. As the 2 can recognize these areas 60 for example at least between the light outcoupling structures 20th be provided and / or between the delimitation of the respective second zone 4th on the one hand and the outermost light-emitting structures 20th on the other hand. How 3rd can be seen, the light outcoupling structure 30th the areas 60 or the only area 60 preferably surrounded or delimited all around in a closed manner. The areas 60 are preferably designed that over these areas 60 emitted light to emit diffusely scattered. For the diffusely scattering light emission by means of the areas 60 can the areas 60 for example at least partially have a Fresnel structure and / or a microstructure film. The diffusely scattering structures of the areas 60 preferably differ from the diffuse scattering structures of the first zone 3rd . A particularly preferred film for diffusely scattering or glare-free emission of light by means of the areas 60 is known under the trade name G-GPHM from bright view technologies.

The optical element 1 is not limited to a specific material as long as the optical element 1 the light output as described above, in particular by means of the zones 3rd and 4th and preferably also by means of the zone 6th , can provide. It is preferred if the optical element 1 is made of a thin-walled material such as a foil. The optical element 1 is therefore preferably flat or planar. The optical element 1 however, it does not necessarily have to be provided in the form of a film, for example the optical element can 1 also be provided in the form of a plate.

The 1 shows an embodiment of the optical element 1 . That in the 1 shown optical element 1 can also be half of a further exemplary embodiment of an optical element 1 so that the complete optical element 1 by mirroring this half on the width side or the inside area 5 having side of the half optical element 1 results. Another embodiment of the optical element 1 can be achieved, for example, by mirroring the optical element 1 according to 1 surrender

An exemplary application of the optical element 1 is the application with a flat luminaire, not shown in detail. Such a flat luminaire generally has a flat light guide with a flat light coupling-out side for emitting light introduced into the light guide. For example, the flat light guide has a front side that has or forms the flat light extraction side, a flat rear side and a front side connecting the front side with the rear side, with the light, for example emitted from a light source (LED, etc.), into the light guide via the front side is initiated. Alternatively or additionally, however, it can also be provided that the light is introduced into the conductor via the rear side into the flat light guide.

The rear side of the light guide preferably has a reflector. The light guide also has decoupling structures, for example in the form of (mechanical) damage to the surface. For example, the rear side of the light guide has the coupling-out structures. The aim of these decoupling structures is to deflect the light coupled into the light guide at the front, for example, to the front of the light guide in order to emit the light over a large area via the light guide via the front or light output side of the light guide. The distance between adjacent coupling-out structures is, for example, approx. 0.5 mm to 2 mm, and / or the coupling-out structures preferably have a size, for example diameter or width, of approx. 0.1 mm to 1 mm

The optical element 1 is provided with respect to the flat lamp in such a way that the flat light coupling side of the optical element 1 is in preferably flat contact with the flat light coupling-out side of the light guide; the optical element 1 is therefore arranged downstream of the lamp or the light guide in the light emission direction. In this way, for example, the optical element 1 cover the entire front of the flat light guide and thus form, for example, the front of the flat light.

Through the contact between the light coupling side of the optical element 1 on the one hand and the flat light coupling-out side of the light guide on the other hand, the light emitted by the light guide via the light coupling-out side of the light guide can be transmitted via the flat light coupling-in side of the optical element 1 into the optical element 1 be initiated. Via the light extraction side 2 of the optical element 1 the light emitted by the flat lamp or the flat light guide can thus be emitted. The above mentioned advantages of the optical element 1 thus have a particularly advantageous effect on the luminaire, so that the flat luminaire appears more three-dimensional or three-dimensional, in particular with little effort.

However, the present invention is not limited to the foregoing preferred embodiments as long as it is encompassed by the subject matter of the following claims. For example, it is not mandatory that the second zones 4th only according to the 2 or in the 3rd or in the 4th or in the 5 second zone shown in each case 4th are designed to produce the different brilliant effect depending on the viewing angle and thus the three-dimensional appearance of the optical element 1 to create. For example, it can be provided that a first number of the second zones 4th according to the in 2 second zone shown as an example 4th is formed, a second number of the second zones 4th according to the in 3rd second zone shown as an example 4th is formed, a third number of the second zones 4th according to the in 4th second zone shown as an example 4th is formed and / or a fourth number of the second zones 4th according to the in 5 second zone shown as an example 4th is trained.

Claims (26)

Optical element (1) for a flat lamp, having - A flat light coupling side for introducing light into the optical element (1) and - One of the planar light coupling-in side opposite the planar light coupling-out side (2) for emitting the light introduced via the light coupling-in side, the light coupling-out side (2) having: ◯ a first zone (3) for diffusely scattering light emission of a first part of the light introduced via the light coupling side, and o several second zones (4) provided in the first zone (3) for light emission of a second part of the light introduced via the light coupling side in such a way that the light emitted via the second zones (4) is at least partially directed in a defined manner. Optical element (1) according to Claim 1 , each of the second zones (4) being delimited from the first zone (3) by a defined shape. Optical element (1) according to Claim 1 or 2 wherein each of the second zones (4) is delimited from the first zone (3) by a circular, elliptical and / or polygonal, in particular essentially hexagonal shape. Optical element (1) according to one of the preceding claims, wherein each of the second zones (4) has a size such as an area delimited by the respective shape, the second zones (4) being provided with different sizes in the first zone (3) are, wherein with increasing distance to an inner region (5) of the optical element (1), preferably second zones (4) with smaller sizes are arranged in the first zone (3), the size preferably being a circumference, and the circumference in particular is preferably in a range from 5 mm to 35 mm, for example in a range from 10 mm to 30 mm. Optical element (1) according to one of the preceding claims, the distance between adjacent second zones (4) increasing with increasing distance from one or the inner region (5). Optical element (1) according to Claim 4 or 5 , wherein the inner region (5) is central with respect to a height and / or width of the optical element, and wherein the inner region (5) is preferably a center of the optical element. Optical element (1) according to one of the preceding claims, wherein the second zones (4) are arranged preferably evenly distributed over at least part and preferably over the entire area of the first zone (3). Optical element (1) according to one of the preceding claims, wherein the second zones (4) each have at least one light outcoupling structure (20, 30, 40, 50), wherein the at least one light outcoupling structure (20, 30, 40) is designed such that the second zones (4) are suitable for the second part of the Not to influence the light input side of the light introduced in a diffusely scattering manner and thus to emit it directly in a defined direction, and / or wherein the at least one light outcoupling structure (20, 30, 40, 50) for emitting light in a defined direction is designed in such a way that the second zones (4 ) are suitable for emitting the second part of the light introduced via the light coupling side in defined directions. Optical element (1) according to Claim 8 , the second zones (4) each having a plurality of light outcoupling structures (20, 50), the plurality of light outcoupling structures (20, 50) preferably distributed evenly over the respective second zone (4), for example according to the shape of the respective second zone (4) are. Optical element (1) according to Claim 8 or 9 , wherein the at least one light outcoupling structure (20, 30, 40, 50) is clearly formed. Optical element (1) according to one of the Claims 8 - 10 , wherein the at least one light outcoupling structure (20) is circular and / or point-shaped. Optical element (1) according to one of the Claims 8 - 11 , wherein the at least one light outcoupling structure (30) is a clear, the shape of the respective second zone (4) corresponding and preferably closed circumferential area, this area preferably surrounding the respective second zone (4). Optical element (1) according to one of the Claims 8 - 12th wherein the light outcoupling structure (40) is clear and the respective second zone (4) substantially completely covers. Optical element (1) according to one of the Claims 8 - 13th , wherein the at least one light outcoupling structure (50) has a plurality of preferably adjoining triangular light outcoupling structures (50) viewed in the direction of the surface normal of the flat light outcoupling side (2) of the optical element (1). Optical element (1) according to Claim 14 , the surface normals (N) of the triangular light outcoupling structures (50) being differently aligned with respect to the flat light outcoupling side (2) and in particular differently in at least six different directions, so that the different alignments of the triangular light outcoupling structures (50) light from the triangular light outcoupling structures (50 ) can be emitted in the different, defined directions, particularly preferably the angle of 60 ° enclosed between two surface normals (N) of differently oriented triangular light output structures (50), seen in the direction of the surface normal of the planar light decoupling side (2) of the optical element (1), 120 °, 180 °, 240 ° or 300 °. Optical element (1) according to Claim 14 or 15th , the triangular light outcoupling structures (50) being formed by sawtooth-like light outcoupling structures (51), the sawtooth-like light outcoupling structures (51) preferably being arranged in an undefined manner in order to provide the differently oriented surface normals (N) of the triangular light outcoupling structures (50), and / or where the sawtooth-like light outcoupling structures (51) each preferably have a base surface (52) and a lateral surface (53) with a side surface (54), the side surfaces (54) of the sawtooth-like light outcoupling structures (51) being the triangular light outcoupling structures (50). Optical element (1) according to one of the Claims 14 - 16 wherein the plurality of triangular light outcoupling structures (50) essentially completely cover the respective second zone (4). Optical element (1) according to one of the Claims 8 - 17th , wherein each of the light outcoupling structures (20, 30, 40, 50) has a width or a diameter in the range from 0.1 mm to 2 mm, preferably in the range from 0.1 mm to 1 mm, and / or each of the Light outcoupling structures (20, 30, 40, 50) has a circumference in the range from 1 mm to 5 mm. Optical element (1) according to one of the Claims 8 - 18th wherein a distance between adjacent light outcoupling structures (20, 50) of the respective second zone (4) is in a range from 0.5 mm to 2 mm. Optical element (1) according to one of the Claims 8 - 19th , a distance being provided between the light outcoupling structure (20, 30, 40, 50) and a delimitation or shape which delimits the respective second zone (4) from the first zone (3), this distance preferably being at least 3 mm amounts to. Optical element (1) according to one of the Claims 8 - 20th wherein each of the second zones (4) is designed in areas (60) in which no light decoupling structure (20, 30, 50) is provided to emit the light in a diffusely scattering manner, these areas (60) at least partially having a Fresnel structure and / or have a microstructure film for diffusely scattering light emission. Optical element (1) according to one of the preceding claims, wherein the optical element (1) has an edge delimiting the optical element (1) and the light coupling-out side (2), preferably circumferentially closed, the edge also preferably circumferentially surrounding the first zone (3) closed limited. Optical element (1) according to any one of the preceding claims, wherein the first zone (3) preferably has microscopic Fresnel structures for diffusely scattering light emission by means of the first zone (3), and / or wherein the first zone (3) through a microstructure film for diffusely scattering Light output is formed by means of the first zone (3). Optical element (1) according to one of the preceding claims, wherein the first zone (3) has a third zone (6) for emitting the light emitted by a secondary lighting means such as an emergency lamp, the third zone (6) preferably being designed that emit light emitted by the secondary illuminant directly, and / or wherein the third zone (6) is preferably designed clearly, and / or wherein the third zone (6) is preferably designed as a recess for receiving the secondary illuminant, and / or wherein the third zone (6) is provided in one or the inner region (5) of the optical element. Optical element (1) according to one of the preceding claims, wherein the optical element (1) is made of a thin-walled material such as a film. Flat luminaire, having - A flat light guide with a flat light coupling-out side for emitting light introduced into the light guide, and - an optical element (1) according to one of the preceding claims, - The flat light coupling side of the optical element (1) is in preferably flat contact with the flat light output side of the light guide, so that light emitted by the light guide via the light output side can be introduced into the optical element (1) via the flat light input side of the optical element.

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