Light guide plate and luminaire with this light guide plate

Abstract

A planar light guide plate (100) for a luminaire, comprising: two planar sides (101, 102) connected to each other by a circumferential end face (103), coupling structures (200) provided on the end face (103) and configured to couple light from outside into the light guide plate (100), and coupling structures (300) provided on one of the planar sides (101, 102) to redirect the light coupled in via the coupling structures (200) into the light guide plate (100) in such a way as to couple it out of the light guide plate (100) via one of the planar sides (101, 102), wherein the coupling structures (200) are configured to couple the coupled light in as directed beams (400), and the coupling structures (300) have an elongated shape, wherein the The output structures (300) extend with their longitudinal axis essentially in the planar plane of the light guide plate (100),and wherein the orientation of each of the output coupling structures (300) is assigned to the direction of one of the beams (400) such that their longitudinal axes are oriented substantially perpendicular to the direction of the assigned beam (400), wherein each of the input coupling structures (200) has, in plan view on one of the planar sides (101, 102), n mutually angled surfaces or flanks (201) via which the coupled-in light is coupled in as n directed beams (400), and wherein the output coupling structures (300) are divided into n groups of substantially the same orientation, characterized in that n > 1, the entirety of the input coupling structures (200) comprises n groups of substantially the same directed beams (400), the n groups of beams (400) are oriented differently, the n groups of output coupling structures (300) are oriented differently,and each of the n groups of output coupling structures (300) is assigned to one of the n groups of beam bundles (400).

Description

The present invention relates to a planar light guide plate for a luminaire having coupling structures for coupling light into the light guide plate and coupling structures for coupling the coupled light out of the light guide plate. The invention further relates to a luminaire equipped with the light guide plate.Corresponding lamps with light guide plates are known from the prior art, in which the light emitted by LEDs, for example, is coupled laterally into the light guide plate. The light then propagates in the light guide plate by total reflection and is deflected, for example, by means of output structures provided on one flat side of the light guide plate in such a way that, as a rule, output from the light guide plate as homogeneously as possible via the opposite flat side. The publications US 2013 / 0 343 086 A1 and US 2015 / 0 160 395 A1 show such light guide plates, which are also disclosed in the preamble of the independent claim 1. US 2005 / 0 013 127 A1 and US 2016 / 0 327 724 A1 show light plates for backlighting LCD displays.The decoupling structures used in this case are often produced as printed dot or area patterns, as laser-cut grooves or other defined structures, for example in special production methods, such as laser cutting or screen printing.The coupling structures used according to the current state of the art predominantly use a straight, continuous profile-i.e. the straight end face of the light guide plate-in order to couple light from outside the light guide plate into the light guide plate. As a result, the light is spread out and coupled into the light guide plate in a non-directional manner, so that the coupling-out structures are struck by light from the most varied directions before the light is coupled out again from the light guide plate. The emerging light has a wide bandwidth at different exit directions from the light guide plate and can thus lead to unfavorable light distributions. Depending on the decoupling structures, known light guide plates usually have a cosine-like light distribution, while others show a peak perpendicular to the light guide plate. In particular, it is thus possible that, on account of the given light distribution, light is coupled out in a concentrated manner in a specific direction if at worst, so that the user is dimmed by the emerging light.However, the solutions known from the prior art do not allow a reliable defined light deflection and, for example, also no effective deblending of the light to be achieved, since the decoupling structures cannot be adapted to the light beams propagating in the light guide plate in the most varied directions. Therefore, many of the solutions known from the prior art use additional optical components, such as diaphragms, optical disks or other additional anti-glare devices.In accordance with the invention, the glare suppression of the light guide plate is understood to mean that, above all, directions in the light distribution that occur at light exit angles of between 65 and 90 degrees are also to be covered. It is precisely this angle range that is largely not covered in previous luminaires, so that a concentration of light occurs in the range from 0 to 65, which leads to a glare effect.It is therefore an object of the present invention to provide a light guide plate and a luminaire equipped therewith, with which a defined light emission is made possible preferably without additional components.This object is achieved by the subject matter of the independent claims. The dependent claims further develop the central idea of the present invention in a particularly advantageous manner.According to a first aspect, the present invention relates to a planar light guide plate for a luminaire. This has two planar sides which are connected to one another by a circumferential end face. Coupling structures are provided on the end face of the light guide plate, which are configured to couple light from the outside into the light guide plate as directed beam bundles. Furthermore, the light guide plate has decoupling structures which are provided on one of the planar sides in order to redirect the light in the light guide plate coupled in via the coupling structures in such a way that it is decoupled from the light guide plate via one of the planar sides. The decoupling structures have an elongate shape, so that they extend with their longitudinal axis substantially in the planar plane of the light guide plate. The coupling-out structures are assigned in their orientation to the direction of one of the beams in such a way that they are oriented with their longitudinal axes substantially perpendicular to the direction of the assigned beam. Furthermore, each of the input structures has n surfaces or flanks which are angled towards one another in a plan view of one of the planar sides and via which the input light is input as an n-directed beam bundle. The decoupling structures are divided into n groups each having substantially the same orientation. Furthermore, n >1. The totality of the coupling structures has n groups of beams of essentially the same direction, the n groups of beams are oriented differently, the n groups of coupling-out structures are oriented differently, and each of the n groups of coupling-out structures is assigned to one of the n groups of beams.In the context of the invention, a "structure" is understood to mean a microscopic or preferably macroscopic structure in the component itself (here in the light guide plate) and in particular on its surface or from its surface extending into the component material as a concave recess.The "coupling structures" used within the scope of the invention are a number of individual structural elements or structural regions which are provided for coupling light into the light guide plate and which have a specific arrangement with respect to one another.Likewise, the "decoupling structures" mentioned within the scope of the invention are individual structural elements or structural regions which are provided to redirect the coupled-in light in the light guide plate and thus to decouple it again from the light guide plate.Furthermore, according to the invention, a "beam" is understood to mean a total of light beams which run substantially in a directed manner. These can be coupled into the light guide plate via a common surface of an individual coupling-in structure. They have a substantially same orientation, that is, there is little divergence between the directions of the individual light beams in the light guide plate. By "low divergence" is meant, for example, a defined fanning out of the light beams of the beam of rays of less than 90° and preferably less than 60°.By adjusting the orientation of the decoupling structures according to the invention to the configuration and the optical property of the coupling structures thus obtained for the defined coupling of beams into the light guide plate, it can be achieved, inter alia, that the light coupled in via the coupling structures can be deflected in a defined manner at the decoupling structures. Thus, the light can be emitted from the light guide plate in a broader fan shape by the decoupling structures, for example, so that an effective glare suppression can be achieved. While one possible object of the present invention is effective anti-glare. The matching provided by the present invention between launch structures and decoupling structures can, however, also be used quite generally for defined light directing and light decoupling.Since the coupling structures and the coupling structures are coordinated with one another in a defined manner, additional optical aids, for example for the purpose of deblending, can be dispensed with. This allows savings in terms of costs and offers more freedom of design in the design and use of the light guide plate or light if the light guide plate is combined with a lighting means.Due to the multiple (n>1) splitting with simultaneous focusing of the light into n individual beams, the decoupling structures can be aligned differently in orientation along their longitudinal axis. The different groups lead to particularly advantageous effects in the deflection of the beams at the decoupling structures, since individual groups can be used in a targeted manner for the deflection of specific beams and the same groups allow other (groups of) beams to pass through substantially unaffected. A defined light guiding and light decoupling can thus be achieved.According to an advantageous embodiment of the light guide plate according to the invention, the cross section of the light guide plate can be formed polygonal in plan view, preferably rectangular or square or triangular and the like, wherein the coupling structures are provided on at least one, a plurality or all of the elongate end face regions.It is thus made possible to provide the coupling structures with the desired properties on a plurality of desired sides and thus to couple the light as uniformly as possible into the light guide plate.According to an advantageous embodiment of the invention, the coupling structures can be provided on regions of the end face which are respectively opposite with respect to the flat sides. This means that the coupling structures are preferably provided on opposite regions or sides of the end face with respect to the planar extent of the light guide plate; they are therefore provided as on opposite end regions or edges of the light guide plate.This configuration makes it possible to achieve a particularly homogeneous light distribution in the light guide plate and to avoid possible interference effects, such as pattern formation in the light guide plate.According to a further preferred embodiment of the invention, the coupling structures can each extend as a concave recess between the flat sides, wherein these are formed at least over a part and preferably over the entire height of the light guide plate.This makes it possible to couple light from the outside particularly uniformly into the light guide plate and split the incoming light and focus it as a beam bundle.According to a further preferred embodiment of the invention, the coupling structures can preferably have two or more mutually angled surfaces or flanks in plan view onto one of the flat sides for coupling in a respective beam bundle. The coupling structures preferably have a triangular shape in plan view of one of the flat sides.This makes it possible to split the light arriving from outside the light guide plate into two (or more) preferably equivalent and directed beam bundles which are oriented substantially perpendicular to the angled surfaces of the coupling structures. This makes it possible to define an orientation of the beams which can be used for advantageous deflection of the beams by the decoupling structures.According to a further preferred embodiment of the invention, the two surfaces angled with respect to one another can enclose an angle in the range from 60° to 120°, preferably of 90°.This makes it possible to split the coupled-in light into preferably two equivalent and directed beam bundles which are oriented substantially perpendicularly to the angled surfaces / flanks of the coupling-in structures and which are furthermore preferably oriented substantially perpendicularly to one another. In addition, a simplification of the production of the coupling-in structures is achieved in this way.According to an advantageous embodiment of the invention, the concave recesses of the coupling structures can have a defined depth and / or a defined ratio of depth to height of the light guide plate or plate thickness starting from the end face.This makes it possible to ensure that the light penetrates into the light guide plate at least up to a width influenced by the profile depth. This also provides a simple parameter for advantageously influencing the luminous properties of the light guide plate. In addition, lighting means (for example, can be used. LEDs) can be accommodated in the concave recesses in a space-saving manner.According to a preferred embodiment of the invention, the decoupling structures can be formed as concave recesses in one of the flat sides.As a result of this configuration, the deflection of the coupled-in light onto the side opposite the coupling-out structures is particularly preferred. Furthermore, the production of the decoupling structures is facilitated, so that costs can be saved during production. In addition, it becomes possible to make the light guide plate as compact as possible and thus to increase the design freedom in combination with lighting means and with other lighting components.According to a preferred embodiment of the invention, the concave recesses of the decoupling structures can have a defined depth and / or a defined ratio of depth to height of the light guide plate or plate thickness starting from the flat side comprising them.As a result, the decoupling structures can be provided in the desired manner for defined light deflection.According to a further preferred embodiment of the invention, the concave recesses of the decoupling structures can each taper towards their two ends, preferably have tapered flanks, in a plan view of the planar side comprising them with respect to their longitudinal axis.By this configuration, it is possible to compactly mount a large number of structures on the surface. As a result, coupling out of the light guide plate as flat as possible can be achieved. In addition, the elongate shape of the decoupling structures allows a suitable assignment to the beams. At the same time, the area available for deflecting the beams is maximized.According to a further preferred embodiment of the invention, the concave recesses of the decoupling structures can have, as seen in the direction of their longitudinal axes, a substantially U-shaped or V-shaped cross section which has two flanks running towards one another.This also makes it possible to form a defined edge on the underside of the decoupling structures, as a result of which the defined deflection of the beam bundle can be particularly preferred. At the same time, in combination with the preceding embodiment, the surface available for deflecting the beams is maximized and optimized in such a way that the impinging beams are deflected particularly advantageously to the opposite flat side. The oblique or curved shape of the decoupling structures also allows a defined deflection of the light for defined decoupling to be achieved.According to a preferred embodiment of the invention, n can have the value 2 and the coupling-out structures of the same group can be oriented substantially perpendicular to the direction of the respectively assigned beam, and / or the coupling-out structures of the same group can be oriented substantially parallel to the respectively assigned angled surfaces or flanks of the coupling-in structures, and / or wherein the coupling-out structures of the one group are oriented substantially perpendicular to the coupling-out structures of the other group.This produces two equivalent beams. The first beam is substantially not influenced by a group of the decoupling structures having a substantially identical orientation, while the second beam impinges substantially perpendicularly on the decoupling structures of this group and is deflected in a defined manner in this way. The same applies in reverse to the other group of decoupling structures. This can ensure that the light of each group is deflected in a targeted manner only by the associated decoupling structures, so that a defined light deflection or light decoupling can be achieved.According to a further advantageous embodiment of the invention, the individual decoupling structures of at least one group of decoupling structures can be arranged slightly inclined with respect to one another in their orientation in the planar plane. In particular, two adjacent decoupling structures are angled slightly relative to one another. For this purpose, their longitudinal axes preferably enclose a maximum angle of 20° and furthermore preferably of a maximum angle of 15° or 10°.This embodiment of the invention can additionally achieve a particularly homogeneous light distribution of the light leaving the light guide plate.According to a further aspect, the present invention further relates to a luminaire which has the above-described light guide plate according to the invention and at least one lighting means which is arranged in such a way as to couple light into the light guide plate via the coupling structures.With a luminaire formed in this way, despite a low design, the light emission characteristic can be set to a wide extent as desired but in a defined manner. It is thus possible, for example, to achieve good deblending even without additional deblending elements.According to a further advantageous embodiment of the invention, it can preferably be provided in the luminaire that at least one lighting means is assigned to each coupling-in structure, wherein preferably the assigned lighting means is arranged in the concave recess of the assigned coupling-in structure.This embodiment of the invention allows the light to be coupled into the light guide plate in a particularly advantageous manner and a particularly uniform and homogeneous light distribution is achieved in the light guide plate. In addition, when the lighting means are arranged in the recess of the coupling structure, a compact design of the luminaire can be achieved.According to a further advantageous embodiment of the invention, it can be provided in the luminaire that the lighting means has an LED, wherein preferably a plurality of LEDs are combined on a printed circuit board, which further preferably extends along a region of the end side having the coupling structures.By means of this embodiment of the invention, the luminaire can be manufactured particularly simply and compactly.Further embodiments and advantages of the present invention are explained on the basis of the following exemplary embodiments in conjunction with the figures of the accompanying drawings. The following are shown: FIG. 1 is a plan view of a detail of a light guide plate according to a first embodiment of the invention, FIG. 2 shows an enlarged illustration of an individual coupling-in structure from FIG. 1 in a plan view of the light guide plate and an exemplary radiation distribution, FIG. 3 shows an individual decoupling structure from FIG. 1 in a plan view of the light guide plate (FIG. 3 a) and a perspective illustration of the decoupling structure (FIG. 3 b), FIG. 4 shows a lateral cross-sectional view of a section of the light guide plate according to FIG. 1, with a schematic illustration of the propagation path of a light beam of one of the beams, and FIG. 5 shows a schematic illustration of the light deflection of a light beam of one of the beam bundles at the output structures in a plan view of the light guide plate according to FIG. 1.FIGS. 1, 2, 3, 4 to 5, and in particular FIG. 1, show by way of example the essential elements of a light guide plate 100 designed according to the invention according to a first embodiment of the invention. The light guide plate is shown with a circumferential end face 103, the coupling structures 200, the coupling structures 300 in an arrangement according to a first embodiment, and a plurality of lighting means 501 in a lighting means holding device 500. The combination of light guide plate 100 and light source 501 forms a luminaire 1 according to the invention.For further description of the properties of the light guide plate 100, reference is preferably made to FIG. 4, which shows, by way of example, a cross section in the longitudinal direction of the light guide plate 100 in plan view. The light-conducting plate 100 has a first planar side 101 and a second planar side 102, both of which are connected to one another by an outwardly encircling end face 103. The two flat sides 101, 102 preferably have a defined distance D from one another, which corresponds to the thickness of the light guide plate 100. The two flat sides 101, 102 are preferably arranged parallel to one another, so that the light guide plate has a uniform thickness D, but alternatively the two flat sides can also have a varying distance D, so that a varying plate height results. The cross section of the light guide plate 100 in plan view is preferably embodied to be polygonal or rectangular, but can also have any other desired geometric shape; for example square, triangular, round, oval and the like.The light guide plate 100 may be made of any material suitable for light guide plates. Transparent plastic materials may be mentioned here by way of example.As can be seen in FIGS. 1 and 2, according to a preferred exemplary embodiment of the invention, the end face 103 following the cross section of the light guide plate 100 consists of individual elongate end face regions 104 which enclose the two planar sides 101, 102. Coupling structures are provided on or in the end face 103 and in particular at least a part of these end face regions 104.According to the detail of the exemplary embodiment in FIG. 1, the coupling structures 200 are arranged on the end face 103 of the light guide plate 100 in an elongate end face region 104 in order to couple light from there into the light guide plate 100. It is also conceivable to provide coupling structures 200 on different end face regions 104 along the end face 103, wherein these are preferably provided on themselves with respect to the flat sides 101, 102, in particular with respect to the flat extension of the light guide plate 100, opposite elongate end face regions 104.The exemplary embodiment in FIG. 1 shows the coupling structures 200 as a plurality of concave recesses arranged next to one another. In this case, the recesses extend from the first planar side 101 to the second planar side 102 along the end face 103 over the entire height or thickness D of the light guide plate 100. It is also conceivable that the concave recesses also extend only over a part of the height or thickness D of the light guide plate 100 or its end face 103. In this case, the position of the individual recesses in the thickness direction can furthermore be chosen as desired.The distance of the coupling structures 200 from one another is also not limited. However, the distance (pitch) of respectively adjacent lighting means 501, in particular LEDs or LED chips, can be used as criterion for defining this parameter. Thus, for example, the pitch distance, as is customary, for example, in commercially available LED modules, can be used as a suitable distance between the individual coupling structures 200.According to the invention, the coupling structures 200 are designed in such a way that they couple in the light coming from the outside as directed beam bundles 400. This is particularly clear in the illustration of FIG. 2, which schematically illustrates the expansion of the light emitted by a lighting means 501 through its beam path. The effect of coupling the light into the light guide as directed beam bundles is preferably achieved in that the coupling structures 200 consist of a plurality of mutually angled surfaces or flanks, each of the angled surfaces splitting and at the same time focusing the incident light, so that a beam bundle 400 aligned with a preferred direction is generated in the light guide plate 100.The exemplary embodiment illustrated in FIGS. 1 and 2 shows the individual coupling structures 200 as two mutually angled surfaces 201, 201, which can preferably have a triangular shape in the plan view shown. The angle enclosed by the two angled surfaces in a plan view of the light guide plate can have values between 60° and 120°, and the two surfaces are preferably arranged substantially at right angles to one another (enclosed angle of approximately 90°).The depth T1 of each coupling-in structure 200 starting from the end face 103 is characterized in FIG. 2 and this can be chosen as desired within the scope of the invention. A defined ratio of depth T 1 to plate thickness D or height of the printed circuit board 100 is preferred.FIG. 1 shows an arrangement of the decoupling structures 300 according to an embodiment on one of the two planar sides 102, 103. The coupling-out structures 300 are provided for the purpose of deflecting the light coupled in via the coupling-in structures 200 in such a way that it is preferably coupled out of the light guide plate 100 again via one of the two planar sides, preferably the planar side opposite the coupling-out structures 300. As can be easily seen in FIG. 1, the decoupling structures 300 can preferably be provided at a distance from the coupling structures 200 arranged on the end face 103.As illustrated in FIGS. 1, 3, and 5, each of the output structures 300 according to the invention has an elongated shape in plan view of the light guide plate 100. The shape of the decoupling structure can preferably be symmetrical to its longitudinal axis, but other embodiments for shaping the decoupling structures 300 in a plan view of the light guide plate 100 are also possible. The longitudinal axes of the individual decoupling structures 300 extend here substantially in the planar plane of the light guide plate 100 and preferably substantially in the plane of the planar side on which they are arranged.FIGS. 3 and 4 are particularly suitable for the further description of advantageous embodiments of the decoupling structures 300 according to the invention. It is thus visible in FIG. 4 that the decoupling structures 300 are preferably formed as concave recesses on or in one of the planar sides 101, 102. FIG. 4 shows the decoupling structures 300 on the first planar side 101 of the light guide plate 100, wherein alternatively provision of the decoupling structures on the second planar side 102 is also equally suitable. In principle, it is also conceivable to provide corresponding decoupling structures 300 on both opposing flat sides 101, 102.FIG. 3 shows a preferred form of the decoupling structure 300 according to a preferred embodiment of the invention in a plan view of the planar first side 101 of the light guide plate 100 comprising it. It can be seen that the decoupling structure 300 formed as a concave recess tapers to a point with respect to its longitudinal axis L towards its two ends 305, 306 and preferably has tapered flanks 301, 301 and furthermore preferably has an elongated middle part 304 therebetween.In addition, in FIGS. 3 and 4, the shape of the decoupling structure 300 in the direction of its longitudinal axis L becomes clear. Thus, the concave recess of the decoupling structure 300 can have a substantially U-shaped or V-shaped cross section as viewed in the direction of its longitudinal axis L. This can in turn have two flanks 302, 302 which run towards one another and meet in a common central edge 303.The depth T2 of each decoupling structure 300 is characterized in FIG. 4 and this can be chosen arbitrarily within the scope of the invention. A defined ratio of depth T2 to plate thickness D or height of the light guide plate is preferred.As already mentioned, the various embodiments of the presented light guide plate 100 can be operated in combination with at least one lighting means 501 as a luminaire 1. For this purpose, the at least one lighting means 501 is arranged in such a way that light can be correspondingly coupled into the light guide plate 100 via the coupling structures 300.Furthermore, at least one lighting means 501 can be attached to such a luminaire 1, preferably to a region of the end face 103 of the light guide plate 100. This can furthermore be fastened in a lighting means holding device 500 in order to thus ensure the fastening of a plurality of lighting means 501. In this case, it is alternatively or additionally also conceivable, as illustrated in the present exemplary embodiments, to provide an array of a plurality of lighting means 501, in which preferably each individual coupling-in structure 200 is assigned a lighting means 501. In this case, as illustrated, for example, in FIGS. 1 and 2, the lighting means 501 can be arranged in the concave recess of the coupling-in structure 200.Different light-emitting elements can be used as lighting means 501, such as LEDs, for example. In this case, a plurality of LEDs are preferably combined on a lighting means holding device or printed circuit board 500, which preferably extends along a region 104 of the end face 103 having the coupling structures 300. A printed circuit board can be used as the illuminant holding device 500, for example, but other devices are also conceivable.The further properties of the presented light guide plate 100 are explained with the aid of FIGS. 1, 2, 4 and 5 :The functional principle for an individual coupling-in structure 200 is clear from FIG. 2. The light impinging on the light guide plate from the outside, which can be emitted by the lighting means 501, for example, impinges on the angled surfaces 201 of the coupling-in structure 200 at angles of + / - 90 degrees here.The planar and mutually angled sides 201 of the coupling structure 200 split the light into equivalent beams 400 and focus the light by causing a reduction in the respective radiation angles of the light by the angled sides 201. Thus, with the arrangement according to the invention presented, a reduced light expansion angle of, for example, approximately + / -28 degrees per beam 400 per angled surface 201 can be achieved, wherein the application is not restricted thereto. This makes it possible for each beam 400 to have a preferred direction of the propagation direction which is oriented substantially perpendicularly to the flat angled side 201.The exemplary embodiments illustrated in the figures show the specific case in which only two angled surfaces 201 are provided on the coupling-in structures 200. Therefore, only two beams 400 are also generated and the decoupling structures 300 can thus be divided into two groups, as can be easily seen in FIG. 1.However, it is also conceivable within the scope of the invention for the light guide plate 100 to have coupling structures 200 with n flat sides or surfaces or flanks 201 respectively angled with respect to one another in plan view of the light guide plate 100. Thus, the light coupled into the light guide plate 100 via the coupling structures 200 can then be split into n differently directed beams 400. The totality of the coupling structures 200 preferably has n groups of essentially identically directed beam bundles 400, respectively. In other words, the n flanks of the coupling structures are divided into n groups, wherein the flanks of a group are all aligned substantially parallel to one another. The coupling structures 200 consequently have the flanks n 1, n 2,..., wherein the first flanks n 1 are all aligned substantially parallel to one another. Likewise, the second flanks n 2 and so on. The flanks n 1 and n 2 etc. are then again angled in a correspondingly defined manner with respect to one another.The decoupling structures 300 can then be divided into n different groups with respect to these n beam bundles 400, wherein each group provides the same alignment or orientation of the decoupling structures 300. In this case, decoupling structures 300 of each of the n groups are each assigned to one of the directions of the n beam bundles 400 by virtue of their longitudinal axes being aligned substantially perpendicular to this direction of the assigned beam bundle 400.As a result, a preferred arrangement of the decoupling structures 300 can be achieved, in which a part of the decoupling structures 300 is arranged in each case perpendicular to one of the beams 400, while the same decoupling structure 300 is oriented, for example, along the / another beam 400. Thus, preferably, an angle of incidence of the respective beam bundle 400 as perpendicular as possible to the respectively associated or facing output coupling structure 300 is made possible. The non-assigned decoupling structures 300 thus substantially do not influence the non-assigned beam 400, as a result of which a preferred defined light decoupling can be achieved; for example, with particularly good deblending.In comparison thereto, in the case of a light coupling without corresponding coupling structures 200, the light would be introduced into the light guide plate with an expansion of + / - 45°, as a result of which matching with corresponding coupling structures 300 is difficult to almost hardly possible.The coupling-out structures 300 do not necessarily have to be oriented parallel to other coupling-out structures 300 in terms of their orientation, as illustrated for example in FIG. 5. They can also be arranged, for example, slightly inclined to one another in the flat plane. For this purpose, their longitudinal axes can enclose an angle of at most 20°, 15° or 10°, for example.The present invention is not limited to the foregoing embodiment as long as it is encompassed by the subject matter of the following claims. For example, the shape of the light guide plate 100 and the material thereof is not limited by the invention. The number, shape, depth and extent and, overall, the dimensions of the coupling structures and coupling structures are also not limited in principle by the invention, provided they are matched to one another for defined light deflection. The number of groups of input-coupling structures and output-coupling structures is also not restricted by the invention.

Claims

Planar light guide plate (100) for a luminaire, comprising: two planar sides (101, 102) which are connected to one another by a circumferential end face (103), coupling structures (200) which are provided on the end face (103) and are configured to couple light from the outside into the light guide plate (100), and decoupling structures (300) which are provided on one of the planar sides (101, 102) in order to redirect the light coupled in via the coupling structures (200) in the light guide plate (100) in such a way as to decouple it from the light guide plate (100) via one of the planar sides (101, 102), wherein the coupling structures (200) are configured in such a way as to couple the coupled-in light as directed beam bundle (400), and the decoupling structures (300) have an elongate shape, wherein the coupling-out structures (300) extend with their longitudinal axis substantially in the planar plane of the light guide plate (100), and wherein the orientation of each of the coupling-out structures (300) is assigned to the direction of one of the beams (400) in such a way that they are oriented with their longitudinal axes substantially perpendicular to the direction of the assigned beam (400), wherein each of the coupling-in structures (200) has, in plan view on one of the planar sides (101, 102), n mutually angled surfaces or flanks (201) via which the coupled-in light is coupled in as n-directed beams (400), and wherein the coupling-out structures (300) are divided into n groups each having substantially the same orientation, characterized in that n>1, the totality of the coupling-in structures (200) has n groups each of substantially identically directed beams (400), the n groups of beams (400) are oriented differently, the n groups of coupling-out structures (300) are oriented differently, and each of the n groups of coupling-out structures (300) is assigned to one of the n groups of beams (400) in each case.Planar light guide plate (100) according to Claim 1, wherein the cross section of the light guide plate (100) is formed in plan view in polygonal, preferably rectangular, fashion, wherein the coupling-in structures (200) are provided on at least one of the elongate end face regions (104).Planar light guide plate (100) according to one of the preceding claims, wherein the coupling structures (200) are provided per se in each case opposite regions or sides of the end face (103) with respect to the planar sides (101, 102), in particular with respect to the planar extent of the light guide plate (100).Planar light guide plate (100) according to one of the preceding claims, wherein the coupling structures (200) each extend as a concave recess between the planar sides (101, 102), at least over a part and preferably over the entire height (D) of the light guide plate (100).Planar light guide plate (100) according to one of the preceding claims, wherein the coupling structures (200) have, in a plan view of one of the planar sides (101, 102), two mutually angled surfaces (201, 201), in particular flanks, for coupling in in each case one of the beams (400) and preferably have a triangular shape.Planar light guide plate (100) according to Claim 5, wherein the two mutually angled surfaces (201, 201) enclose an angle in the range from 60° to 120°, preferably of 90°.Planar light guide plate (100) according to one of the preceding claims, wherein the decoupling structures (300) are formed as concave recesses in one of the planar sides (101, 102).Planar light guide plate (100) according to Claim 7, wherein the concave recesses of the decoupling structures (300), in plan view of the planar side (101, 102) comprising them, each have, with respect to their longitudinal axis, tapering towards their two ends (305, 306), preferably have tapering flanks (301, 301).Planar light guide plate (100) according to either of Claims 7 and 8, wherein the concave recesses of the decoupling structures (300), as seen in the direction of their longitudinal axis, have a substantially U-shaped or V-shaped cross section which has two flanks (302, 302) running towards one another.Planar light guide plate (100) according to one of Claims 1 to 9, wherein n has the value 2 and the coupling-out structures (300) of the same group are oriented substantially perpendicularly to the direction of the respectively assigned beam (400), and / or the coupling-out structures (300) of the same group are oriented substantially parallel to the respectively assigned angled surfaces or flanks (201) of the coupling-in structures (200), and / or wherein the coupling-out structures (300) of the one group are oriented substantially perpendicularly to the coupling-out structures (300) of the other group.Planar light guide plate (100) according to one of Claims 1 to 10, wherein the individual decoupling structures (300) of at least one group of decoupling structures (300) are arranged slightly inclined with respect to one another in their orientation in the planar plane, preferably their longitudinal axes enclose a maximum angle of XY°.Luminaire, comprising a light guide plate (100) according to one of the preceding claims and at least one lighting means (501) which is arranged in such a way as to couple light into the light guide plate (100) via the coupling structures (200).Luminaire according to claim 12, wherein each coupling-in structure (200) is assigned at least one lighting means (501), preferably the assigned lighting means (501) is arranged in the concave recess of the assigned coupling-in structure (200).Luminaire according to claim 12 or 13, wherein the lighting means (501) comprises an LED, wherein preferably a plurality of LEDs are combined on a printed circuit board (500), which further preferably extends along a region of the end side (103) comprising the coupling structures (200).

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