DE102021131390A1 - LIGHTING DEVICE - Google Patents

Abstract

The invention relates to a lighting device with a light-conducting plate, which comprises a first side and a second side opposite the first side. The lighting device has a plurality of circular-cylindrical cutouts made in the plate for coupling light into the plate and a plurality of light sources, each of which emits light into one of the cutouts.

Description

The present invention relates to a lighting device with a light-conducting plate.

Lighting devices with light-conducting plates are known in principle, with the light-conducting plate generally serving to emit light that is coupled into the plate uniformly over the extent or area of the plate.

The light is often coupled into one or more narrow sides of the plate. This results in the disadvantage that the size of the light-guiding plate is limited, since otherwise the light intensity that can be coupled out would be greatly unevenly distributed over the surface. Typically, the lateral coupling takes place via LEDs, which are arranged on strip-shaped circuit boards. White low-power LEDs are usually arranged close together for this purpose. Due to the limited coupling area available, such lighting devices cannot be made very bright, since the entire light output has to be coupled into the narrow side, which can lead to temperature problems, for example.

An alternative is coupling from the rear, i.e. into one of the "large" surfaces of the light-conducting plate. The disadvantage here is that the coupling cannot take place with a high level of efficiency. In addition, the problem can arise that in the coupling area there are in each case significantly lighter areas in the plate. When using multicolored LEDs, there is also the problem of color mixing, since the emitters are arranged next to each other within an LED housing and visible areas of differently mixed light thus lead to an irregular color and brightness impression.

It is therefore the object on which the invention is based to specify a lighting device with a light-conducting plate which enables strong and preferably uniform light emission even over large and possibly irregularly shaped surface areas.

This object is achieved by a lighting device according to claim 1.

The lighting device according to the invention comprises a light-conducting plate which comprises a first side and a second side opposite the first side. The lighting device has a plurality of recesses made in the plate for coupling light into the plate. The recesses can preferably be circular-cylindrical. Finally, the lighting device includes a plurality of lighting means, each of which emits light into one of the recesses.

The invention is based on the finding that the circular-cylindrical cutout and the coupling angles that can be achieved by the circular-cylindrical cutouts, which can lead to total reflection in the light-conducting plate, enable very efficient light coupling into the light-conducting plate, which means that the lighting device can also be used with large surfaces can ensure a strong and even light emission.

In addition, it is advantageous that the circular-cylindrical cutout can also be made in the light-conducting plate in a simple manner by means of a milling cutter, even on large and irregularly shaped surfaces. The lighting device can therefore be produced very economically.

During operation, the lamps then emit light into the recesses, with a high proportion of the light emitted by the lamps into the recess also being coupled into the light-conducting plate through the circular-cylindrical recess. In the light-guiding plate, the coupled-in light is then distributed over the extent of the plate and, as explained in more detail below, can be coupled out uniformly over the extent of the light-guiding plate. The decoupling can take place, for example, via the first side. Alternatively or additionally, the decoupling takes place via both flat sides. A reflector attached to the rear side then has the task of reflecting the undesired part back through the plate and thus making it usable.

Coupling into a flat side of the light-guiding plate also results in the advantage that the light-guiding plate (and thus the lighting device) can have any outer contours. The lighting device can be shaped, for example, in the shape of a star, polygonal, round, irregular, etc., it also being possible to introduce flat cutouts into the lighting device. Such sections are not possible with lateral light coupling, as otherwise dark areas would arise.

The coupling according to the invention also permits good color mixing, so that the lighting device emits light of a uniform color even when using lighting means which emit different colors.

In addition, due to the structure being the same in all areas of the lighting device, production is simplified, so that an economical manufacture is possible production is possible from a batch size of one (also, for example, with any free form).

The first side can be, for example, that side of the light-guiding plate that has the greatest extent and/or area. The plate can in particular be cuboid, so that the recesses are introduced into the plate from the second side.

The recesses are preferably designed as vertical and/or straight circular cylinders. This means that an end face or base area of the circular cylinder is flat. The base area can preferably also run parallel to the area of the first side.

The thickness of the plate is preferably 50 times, in particular 100 times, thinner than the width and/or the length of the light-guiding plate.

The recesses can be distributed regularly or irregularly over the light-conducting plate. The light output and/or heat output can be distributed over a large area by the distribution of the recesses and thus also the distribution of the lighting means, so that the lighting device can in principle be operated with a high light output.

The light-guiding plate is preferably formed from PMMA (polymethyl methacrylate, also called acrylic glass). It has been found that the circular-cylindrical cutout, together with the refractive index of PMMA (n=1.49), leads to a very efficient coupling of the light radiated into the cutouts by the illuminants into the light-conducting plate.

It is also possible to produce the light-conducting plate from other light-conducting materials which have a refractive index similar to PMMA and, for example, have a refractive index between 1.4 and 1.6.

Further embodiments of the invention can be found in the description, the drawings and the dependent claims.

According to a first advantageous embodiment, at least one of the recesses has a radiation opening on only one side in the area of a base area. The irradiation opening generally serves to allow light to enter the associated recess. This can also apply to most or all of the recesses. Accordingly, the recesses can be designed as blind holes. This means that material of the light-guiding plate is still present between the surface of the first side of the plate and the recess, whereas an opening towards the recess can be provided in the second side of the plate. Alternatively, it is possible that the recess is first formed by drilling through the light-conducting plate, but the recess is then closed on one side (e.g. by a type of plug which has a satin surface or a milky structure, for example). A base area of the circular-cylindrical cutout can therefore be designed to be at least partially open, in which case the opening can in particular only be present there. The illuminant can also project into the opening or emit light into it. The recesses, which are only open on one side, simplify a (splash)waterproof construction of the lighting device, for example.

According to a further advantageous embodiment, at least one lamp emits light through the irradiation opening into the recess. As already mentioned above, the irradiation opening can serve to ensure that the light from the lamps reaches the recess there. In particular, the light source emits the light directly through the irradiation opening into the cutout, so that the light from the light source does not initially pass through the material of the panel into the cutout. The above statements can in turn apply to most or all of the lighting means of the lighting device.

According to a further advantageous embodiment, the ratio of the depth of at least one of the recesses to its diameter is at least 2:1, preferably 3:1, particularly preferably 4:1. The depth is to be understood in particular as extending in a direct direction from the second to the first side. The coupling efficiency is increased by using a circular cylinder that is as narrow as possible as a recess in relation to the depth of the plate. The above statements can in turn apply to most or all of the recesses in the lighting device.

According to a further advantageous embodiment, a light-emitting surface of at least one lamp is smaller than 16 mm ² , preferably smaller than 8 mm ² or 1 mm ² . For this purpose, the light source can preferably be in the form of an LED light source. As a result of the small light-emitting surface, a light source that is as punctiform as possible is created, it being shown here in turn that the punctiform light source in combination with the circular-cylindrical cutout enables efficient light coupling into the light-guiding plate. The above statements can in turn also apply to the majority or all of the lighting means. It goes without saying that a light source can also emit several different colors. A light source can be, for example, an RGBW LED (red-green-blue-white LED).

It should be made clear below why the aforementioned sizes of the light-emitting surface and the ratios of depth and diameter of the recesses are advantageous.

berechnet werden, wobei n₁ der Brechungsindex des Mediums in der Aussparung und n₂ der Brechungsindex des Mediums der lichtleitenden Platte ist. θ_i ist der Winkel zwischen dem Lot auf die Grenzfläche und dem einfallenden Licht. θ_t ist der Winkel zwischen dem Lot auf die Grenzfläche und dem in die lichtleitende Platte transmittierten Licht (bzw. der jeweiligen elektromagnetischen Welle).The light emitted by the lighting means is preferably emitted into the recess and enters the material of the light-conducting plate at the interface between the projection and the light-conducting plate. There is usually air in the gaps, so that light refraction occurs, for example, when transitioning to PMMA, which is optically more dense. The refraction of light can be calculated using the formula $$\frac{n_2}{n_1}=\frac{sin{\theta }_i}{sin{\theta }_t}$$

can be calculated, where n ₁ is the refractive index of the medium in the recess and n ₂ is the refractive index of the medium of the light-guiding plate. θ _i is the angle between the perpendicular to the interface and the incident light. θ _t is the angle between the perpendicular to the interface and the light (or the respective electromagnetic wave) transmitted into the light-conducting plate.

$$t_s=\frac{2{\text{n}}_1\text{ cos }{\theta }_i}{n_1\text{ cos }{\theta }_i+n_{2}cos{\theta }_t}$$

Furthermore, starting from the Fresnel formulas, the portion of the electromagnetic wave (ie the light) reflected at the interface and the portion of the electromagnetic wave (ie the light) transmitted at the interface can be calculated. The proportions of reflected light r _s and transmitted light t _s can be determined as follows: $${\mathrm{right}}_s=\frac{n_{1}cOs{\theta }_i-{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="DE102021131390A1\_0008.png"\; state="\{\{state\}\}">n</figure-callout>}}_2\text{cos}{\theta }_t}{n_1\text{cos}{\theta }_i-{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="DE102021131390A1\_0008.png"\; state="\{\{state\}\}">n</figure-callout>}}_2\text{cos}{\theta }_t}$$

$$t_s=\frac{2{\text{n}}_1\text{cos}{\theta }_i}{n_1\text{cos}{\theta }_i+n_{2}cOs{\theta }_t}$$

It turns out that the fraction of the transmitted light t _s is higher at small angles of θ _i . For this reason, it is advantageous to use as small a light-emitting surface as possible (ie as punctiform an emitter as possible), since a larger proportion of the light then hits the interface at a smaller angle θ _i (ie steeply).

In addition, it results that the depth of the recess should be particularly large compared to its diameter. Even then, a larger part of the light from the lighting means can in turn be coupled into the light-conducting plate.

According to a further advantageous embodiment, a preferably circular cover is attached in the area, in particular above, the base area of at least one recess, which cover is designed to absorb at least part of the light emitted into that recess, which is coupled out again or transmitted directly above the light source in particular will bounce back and/or absorb into the plate. The cover can be mounted in particular on the first side of the light-guiding plate and can be circular in shape, for example. Alternatively or additionally, the cover can also be arranged within the recess. The cover prevents light radiated directly from the light sources through the light-conducting plate from leading to brighter areas on the light-conducting plate. The material and/or the thickness of the cover can be selected in such a way that the light radiating through the cover has approximately the same intensity or the same luminous flux as the light radiated in other areas of the lighting device. Again, the above statements can also apply to most or all of the recesses.

According to a further advantageous embodiment, the cylinder axes of several of the recesses are arranged parallel to one another and are preferably aligned parallel to a normal to the largest plane of the plate. This can also apply to all recesses. The recesses are therefore all introduced into the light-conducting plate in the same direction. The largest plane of the light-guiding plate can be formed by the first side, for example. For this purpose, the first side can be designed as a plane. If the cylinder axes are aligned parallel to the normal to this largest plane, the recesses can be made by vertical drilling and/or polishing milling in the z. B. second side of the plate can be created in a simple manner.

According to a further advantageous embodiment, the plate is transparent and/or translucent. The transparent and/or translucent design enables good light conduction within the panel.

According to a further advantageous embodiment, the plate has, preferably on the second side, a plurality of imperfections, for example engravings, which are designed to decouple light guided in the plate. For example, the imperfections may have a repeating pattern, e.g. e.g. there may be straight imperfections forming a pattern of lines, dots, a diamond or a checkerboard pattern. The imperfections are, in particular, elongated indentations in the surface of the plate (eg engravings), resulting in imperfections on the surface of the plate which then lead to light being coupled out. The imperfections can be created, for example, by laser engraving. Alternatively or additionally, the imperfections also be attached to the first side and/or lie within the light-guiding plate.

The imperfections can also be arranged, at least in part, rotationally symmetrically around the cylinder axes of the recesses. For example, the imperfections can include concentric circles, the distance between which decreases as the distance from a cylinder axis increases. In this way, light can be coupled out uniformly around a cylinder axis or around a recess.

In particular, the imperfections (e.g. their density, their spacing, their size and/or their course) and/or the positioning of the recesses can be adapted to the contour of the light-guiding plate. For example, the course of the imperfections at the edge of the light-conducting plate can follow the contour of the light-conducting plate. As the distance from the recesses increases, the density of the imperfections can increase, in particular in a non-linear manner.

According to a further advantageous embodiment, an illuminant carrier, in particular a plate-shaped one, is attached to the second side. The illuminant carrier can, for example, be glued to the light-conducting plate, in particular only around the edge of the light-conducting plate. The illuminant carrier is preferably z. B. reflective, specular or made of a material with a light color (e.g. white). The illuminant carrier can attach the illuminants in order to hold the illuminants in a defined position relative to the light-conducting plate.

The side of the illuminant carrier facing away from the light-conducting plate can be provided, at least in regions, with a heat-conducting foil, in particular with a laminated metal foil.

A watertight lighting device can be created in a simple manner by the, in particular circumferential, bonding of the illuminant carrier to the light-conducting plate. The waterproofness can be maintained even in the presence of the cutouts mentioned herein. In particular, the lighting device can, for example, meet the protection requirements of class IP65 or higher.

The illuminant carrier preferably has a coefficient of expansion which differs from the coefficient of expansion of the material of the light-conducting plate by less than 5%, preferably by less than 2%. In this way, the lighting device can be used in a wide temperature range without shifting the position of the lighting means relative to the light-conducting plate when it is heated. In addition, there is the advantage that heat development of the lighting means leads to little or no mechanical stress for the lighting device.

According to a further advantageous embodiment, at least one of the lighting means is arranged on a circuit board, the circuit board being arranged in a recess of the lighting means carrier. One lamp or a group of lamps can be arranged on one of the circuit boards. For example, four light sources that can emit the colors red, green, blue and white (RGBW) can also be present on a circuit board. Such a group of light sources can then emit light into precisely one of the recesses.

The circuit board with the illuminant or illuminants can then be inserted into the depression of the illuminant carrier, the depression then fastening the circuit board in such a way that the circuit board is pressed against the second side of the light-conducting plate or is fastened adjacent or adjacent to the second side. For this purpose, the recess can be designed to fit the circuit board.

The circuit board can have a plurality of contact sections which extend away from a mounting location of the lighting means on the circuit board. Accordingly, the circuit board can, for example, be H-shaped, cross-shaped or star-shaped. Contact surfaces can be provided on the contact sections, to which a power supply for the lamps z. B. can be soldered or welded. Alternatively or additionally, the power supply can be connected directly to at least part of the lighting means (i.e. without circuit boards).

The above explanations can also apply to all lighting means or the majority of lighting means. In particular, one group of light sources is fastened on a single circuit board and is electrically contacted through the circuit board.

According to a further advantageous embodiment, the circuit boards are contacted by means of connecting wires. The connecting wires are preferably attached to the surface of the illuminant carrier, the connecting wires being attached to the illuminant carrier at least in regions by means of a joint and/or adhesive connection.

Alternatively or additionally, the lighting means can also be electrically contacted in general by means of the connecting wires. The connecting wires can NEN also be attached at least partially to the light-conducting plate by means of the joining and/or adhesive connection. In addition, it is also possible for one, several or all circuit boards to be attached to the light-conducting plate. Instead of the illuminant carrier, a reflector or an end plate can then be attached to the light-conducting plate, for example.

The joining and/or adhesive connection for the connecting wires makes it possible to lay the connecting wires in almost any desired route. If the outer contour of the lighting device is irregularly shaped, for example, the recesses and thus the lamps must also be arranged irregularly in order to ensure that the light is emitted evenly. Due to the way the connection wires are laid as described here, such irregularly arranged lamps/boards can also be contacted reliably, in particular by machine and automatically. This enables the economical production of small series and also individual pieces.

In the case of the joint connection, the connection wire is preferably attached to the illuminant carrier and/or the light-conducting plate without the addition of additional material. The joint connection can be created, for example, by a material connection and/or a form fit between the lamp carrier and/or the light-conducting plate and the connecting wire. This type of attachment of the connecting wire to the illuminant support and/or the light-guiding plate is therefore particularly suitable for automated manufacture, which is more cost-effective, faster and more reproducible than manual methods. Apart from that, there is no need to provide additional material or additional fastening means, such as clamps, adhesive and the like, which in turn means that the lighting device can be produced more economically. In addition, the connecting wire can be stretched over the contact surfaces during the manufacturing process. As a result, the connecting wire stretched in this way can be electrically connected to the contact surfaces of the lamps in a simple manner, e.g. by means of soldering or welding.

For example, the connecting wire in the area of the joint is at least partially surrounded, in particular directly, by the illuminant carrier and/or the light-conducting plate. This means that the connection wire can be embedded at least partially in the area of the joint in the illuminant carrier and/or in the light-conducting plate for its attachment. This can be done, for example, by applying pressure to the connecting wire and/or by using high-frequency mechanical vibrations. The vibrations can cause the connecting wire to move relative to the illuminant support and thus heat it up, resulting in a connection of connecting wire and illuminant support and/or light-conducting plate and the connecting wire can also be embedded in the illuminant support. In particular, the connecting wire has a diameter of less than 1.0 mm, in particular less than 0.5 mm, preferably less than 0.25 mm. Such a thin connection wire is particularly suitable for thin light source carriers, as a result of which the lighting device can be made particularly thin overall.

In particular, the joint connection includes material of the illuminant carrier and/or the connecting wire that is liquefied at times, the connecting wire having in particular one or more insulating layers. The insulating layers can have different melting points. For example, by heating using an oscillating body and/or a heated stamp, the illuminant carrier/the light-conducting plate and/or the insulating layer of the connecting wire can be partially liquefied and in this way, after cooling and the associated solidification, the joint of illuminant carrier and connecting wire can be created. The connecting wire preferably comprises an insulating layer. This may be an easily fusible layer such as PVB (polyvinyl butyral) and may have its melting point at a temperature of about 120°C, such a temperature being easily reached by means of a vibrating body or a heated stamp. For example, the connecting wire can have a conductive copper core surrounded by a temperature-stable insulating layer.

The way in which the connection wires are laid as described here also allows the lighting means to be contacted in such a way that the lighting means can be controlled individually or in a number of groups. For example, a lighting device can include at least three or five groups of lighting means. Instead of being controlled via separate connection wires, the lamps can also be controlled individually or in groups, for example using electronic solutions. Individual activation or activation in groups makes it possible, for example, to illuminate different surface areas of the lighting device differently or, for example, to let a red area wander over the surface of the light-conducting plate.

According to a further advantageous embodiment, the lamp includes additional lighting means, for example additional LEDs, which are arranged in or on the lighting means carrier. In contrast to the lamps, in the area of the additional Illuminants each introduced no recess in the light-conducting plate. The additional lighting means are therefore preferably arranged completely outside of the light-conducting plate. Moreover, in particular, no covers are provided in the area of the additional lighting means. The additional lighting means can thus shine through the light-conducting plate at least essentially in the direction of a normal to the largest plane of the plate. The effect of additional punctiform lights can thus be produced in the homogeneously illuminated plate.

The additional lamps can also be arranged on circuit boards and contacted by means of connecting wires. Except for the above differences in the arrangement of the additional lamps, the statements on the lamps for the additional lamps apply accordingly.

In a further advantageous embodiment, an exemplary lighting device is described in which the recesses each have a radiation opening on only one side in the area of a base area and the recesses are distributed over the surface of the plate, with the light sources each emitting light directly through a radiation opening into the recess emit and in the area of the base areas of the circular-cylindrical recesses circular covers are attached, which are designed to reflect and/or absorb at least part of the light emitted into that recess into the plate, the cylinder axes of the recesses being arranged parallel to one another and parallel to are aligned with a normal to the largest plane of the plate, the plate having a plurality of imperfections on the first and/or second side, which are designed to couple out light guided in the plate and the imperfections form repeating patterns, wherein on the second side a plate-shaped illuminant carrier is attached, which comprises light-reflecting or reflective material, the illuminants are arranged on circuit boards, the circuit boards being arranged in depressions in the illuminant carrier and being contacted by means of connecting wires and the connecting wires being connected at least in regions to the surface by means of a joint and/or adhesive connection of the lamp holder are attached.

The lighting device preferably comprises at least 10 or 20 recesses and/or lighting means or groups of lighting means.

According to a further advantageous embodiment, the plate has a central cutout which is peripherally delimited by the material of the plate.

Viewed in the plane, the section can therefore be delimited on all sides by the plate. The cutout can be, for example, a circular or rectangular cutout of the plate. The section can be significantly larger than a recess, for example the section can occupy 10, 20, 50 or 100 times the area of a recess. The cutout can also extend through the illuminant carrier, preferably in alignment. Such a cutout is not possible, for example, with one-sided coupling from the side, since otherwise it would not be possible to transmit light to areas beyond the cutout.

The invention also relates to a method for producing a lighting device of the type explained herein, in which the outer contour of the lighting device, the arrangement of the cutouts and/or one or more cutouts in the lighting device are defined using a computer program, in particular in a web interface, and then the Outer contour of the lighting device, the arrangement of the recesses and/or the one or more cutouts in the lighting device are manufactured, in particular automatically.

The lighting device can therefore be implemented in a computer program, e.g. a web interface, for example by means of a GUI (Graphical User Interface), it then being possible to manufacture the lighting device created in this way exactly according to the specifications in the computer program. For example, any outer contour, e.g. with or without cutouts, can be specified, which is then, in particular automatically, cut from a light-conducting plate. The above-described automatic laying and/or placement of the connection wires also makes it possible, with any arrangement of the cutouts, in particular one that is generated manually and/or algorithmically, to make electrical contact with the lighting means fitted there.

In this way, customer-specific lighting devices can be easily defined, e.g. on the Internet. The number, distribution and/or power of the lamps can also be specified in the configuration. The method thus enables the production of a wide variety of lighting devices with little administrative and process effort.

• - einer lichtleitenden Platte, welche eine erste Seite und eine der ersten Seite gegenüberliegende zweite Seite umfasst,
• - einer Mehrzahl von in die Platte eingebrachten Aussparungen zur Lichteinkopplung in die Platte,
• - mehrere Leuchtmittel, welche jeweils Licht in eine der Aussparungen hinein emittieren, und
• - einem an der zweiten Seite angebrachten, insbesondere plattenförmigen, Leuchtmittelträger,

wobei die Leuchtmittel direkt oder indirekt mittels Anschlussdrähten kontaktiert sind und die Anschlussdrähte an dem Leuchtmittelträger und/oder an der lichtleitenden Platte befestigt sind, wobei die Anschlussdrähte insbesondere mittels einer Füge- und/oder Klebeverbindung zumindest bereichsweise an dem Leuchtmittelträger und/oder der lichtleitenden Platte befestigt sind.Finally, the invention also relates to a further embodiment of a lighting device

• - a light-conducting plate, which comprises a first side and a second side opposite the first side,
• - a plurality of recesses made in the plate for coupling light into the plate,
• - a plurality of light sources, each of which emits light into one of the recesses, and
• - an illuminant carrier attached to the second side, in particular in the form of a plate,

wherein the lighting means are contacted directly or indirectly by means of connecting wires and the connecting wires are attached to the lighting means carrier and/or to the light-conducting plate, the connecting wires being fastened at least in regions to the lighting means carrier and/or the light-conducting plate, in particular by means of a joint and/or adhesive connection are.

In contrast to the embodiment of the lighting device described above, the recesses in the further embodiment can also have a shape other than circular-cylindrical, for example hemispherical, polygonal and/or with sloping end faces.

Fastening the connecting wires to the illuminant carrier and/or the light-guiding plate, in particular by means of the joining and/or adhesive connections, makes it possible to easily manufacture different shapes of the lighting device. For example, the connection wires can be attached directly to the light sources. Alternatively, the lighting means can also be attached to circuit boards, with the circuit boards being contacted by the connecting wires.

For the other embodiment of the lighting device and the method according to the invention, the embodiments relating to the first-mentioned lighting device according to the invention apply correspondingly. This applies in particular to advantages and embodiments.

• 1 eine Leuchtvorrichtung in einem seitlichen Querschnitt;
• 2 einen Teil einer Leuchtvorrichtung in einer perspektivischen Ansicht auf die erste Seite der lichtleitenden Platte;
• 3A einen Teil einer Leuchtvorrichtung gemäß einer ersten Ausführungsform in einer perspektivischen Detailansicht auf die erste Seite der lichtleitenden Platte;
• 3B einen Teil einer Leuchtvorrichtung gemäß einer zweiten Ausführungsform in einer perspektivischen Detailansicht auf die erste Seite der lichtleitenden Platte; und
• 4 eine weitere Ausführungsform einer Leuchtvorrichtung in einem seitlichen Querschnitt.

The invention is described below purely by way of example with reference to the drawings. Show it:

• 1 a lighting device in a lateral cross section;
• 2 a part of a lighting device in a perspective view of the first side of the light-conducting plate;
• 3A a part of a lighting device according to a first embodiment in a perspective detailed view of the first side of the light-conducting plate;
• 3B a part of a lighting device according to a second embodiment in a perspective detailed view of the first side of the light-conducting plate; and
• 4 a further embodiment of a lighting device in a lateral cross section.

1 shows a lighting device 10 with a light-conducting plate 12 in a cross-sectional view. A plurality of circular-cylindrical recesses 14 are made in the light-guiding plate. The recesses 14 have (in the representation of 1 ) in the lower area a radiation opening 15.

An illuminant carrier 16 is glued to the light-conducting plate 12 by means of an adhesive 18 all the way around.

A plurality of depressions 20 are provided in the illuminant carrier 16, in each of which circuit boards 22 are held. LEDs 24 are contacted on the circuit boards 22 as illuminants.

Covers 26 are attached to a first side 28 of the plate 12 above the LEDs 24 and above the recesses 14 . The covers 26 can also be arranged on an end face of the recesses 14 . The covers 26 serve to prevent the light from the LEDs 24 from shining directly through the plate and to break up transmitted light, i.e. light that is directly coupled out, and to couple it back into the plate 12 at least partially.

The illuminant carrier 16 is glued to a second side 30 of the light-guiding panel 12 . The side of the illuminant carrier 16 facing away from the light-conducting plate 12 is provided with a heat-conducting foil 37, which is, for example, a laminated metal foil.

The first side 28 forms (together with the second side 30) the largest surface of the plate 12. On the first side 28 a normal N is drawn on this surface.

It goes without saying that the ratio of depth and diameter of the recesses 14 shown in the figures does not correspond to the ratio specified above for reasons of better representation.

2 shows the lighting device 10 in a perspective view from above the first side 28. In 2 connecting wires 32 are shown which electrically contact the circuit boards 22 of the various LEDs 24 . The connecting wires 32 can in particular be automatically laid on the illuminant carrier 16 and with the illuminant carrier 16 glued or connected by means of a joint connection.

The 3A and 3B relate to two different embodiments and show a detail 2 , Wherein the cover 26 is not shown there, in order to be able to recognize the circuit board 22 better. The 3A and 3B also show imperfections in the form of engravings 34.

According to 3A the engravings 34 are punctiform and introduced into the surface of the second side 30 . The engravings 34 form a radial pattern of circles around the recesses 14 so that light is emitted or decoupled uniformly from the plate 12 .

In contrast to 3A are in 3B the engravings 34 are lined to create a diamond pattern. According to 3B the engravings 34 are introduced into the surface of the first side 28.

In 3A and 3B connection pads 36 are also shown, in particular, on which the connection wires 32 are electrically contacted with the circuit boards 22 . The circuit boards 22 are H-shaped, with the connection pads 36 each being attached to extensions of the circuit boards 22 .

4 shows a further embodiment of the lighting device 10 in a lateral cross-sectional view. In contrast to the embodiment of 1 includes the embodiment of 4 Additional LEDs 38, which are arranged on boards 22. The circuit boards 22 are in turn arranged in recesses 20 of the illuminant carrier 16 , but no recesses 14 and no covers 26 are arranged above the additional LEDs 38 . The additional LEDs can thus radiate through the plate 12 in the direction of the normal N.

When the lighting device 10 is in operation, the LEDs 24 and the additional LEDs 38 are supplied with power via the connecting wires 32, with the LEDs 24 and the additional LEDs 38 being able to be supplied, for example, via separate or common circuits.

The LEDs 24 then radiate light through the irradiation openings 15 directly into the cutouts 14 , the light being coupled in particular through the side walls of the cutouts 14 into the light-guiding plate 12 . The light coupled in in this way is then passed on within the plate 12 and coupled out uniformly on the surface of the first side 28 through the engravings 34 . By distributing the LEDs 24 over the entire surface of the light-guiding plate 12, lighting devices 10 can in principle be created in any size, which allow a uniform light emission.

Reference List

10

lighting device

12

light-conducting plate

14

recesses

15

inflow opening

16

bulb holder

18

adhesive

20

deepening

22

circuit board

24

LEDs

26

cover

28

first page

30

second page

32

hookup wire

34

engraving

36

connection pad

37

thermally conductive foil

38

Additional LED

N

normal

Claims (18)

Lighting device (10) with - a light-conducting plate (12) which comprises a first side (28) and a second side (30) opposite the first side (28), - a plurality of circular-cylindrical recesses (14) introduced into the plate (12) for coupling light into the plate (12), and - Several lamps (24), each of which emits light into one of the recesses (14). Lighting device (10) after claim 1 wherein at least one of the recesses (14) has a radiation opening (15) on only one side in the area of a base area. Lighting device (10) after claim 2 , wherein at least one illuminant (24) emits light through the irradiation opening (15) into the recess (14). Lighting device (10) according to one of the preceding claims, wherein the ratio of the depth of at least one of the cutouts (14) to its diameter is at least 2:1, preferably 3:1, particularly preferably 4:1. Lighting device (10) according to one of the preceding claims, wherein a light-emitting surface of at least one lighting means (24) is smaller than 16 mm ² , preferably smaller than 8 mm ² or 1 mm ² . Lighting device (10) according to one of the preceding claims, wherein a, preferably circular, cover (26) is attached in the area of the base area of at least one recess (14), which is designed to cover at least part of the light emitted into that recess (14). reflect and/or absorb into the plate (12). Lighting device (10) according to one of the preceding claims, wherein the cylinder axes of several of the recesses (14) are arranged parallel to one another and are aligned parallel to a normal (N) to the largest plane of the plate (12). Lighting device (10) according to one of the preceding claims, wherein the plate (12) is transparent and/or translucent. Lighting device (10) according to one of the preceding claims, wherein the plate (12) has a plurality of imperfections (34) on the first and/or second side (28) which are designed to decouple light guided in the plate (12). Lighting device (10) according to one of the preceding claims, wherein a, in particular plate-shaped, lighting means carrier (16) is attached to the second side (30). Lighting device (10) after claim 10 , wherein at least one of the light sources (24) is arranged on a circuit board (22), the circuit board (22) being arranged in a recess (20) of the light source carrier (16). Lighting device (10) after claim 11 , wherein the circuit boards (22) and/or the lamps (24) are contacted by means of connection wires (32) and the connection wires (32) are attached to the surface of the lamp support (16), the connection wires (32) being connected by means of a joining and / or adhesive bond are attached at least partially to the illuminant carrier (16). Lighting device (10) after claim 11 , Wherein the circuit boards (22) and/or the illuminants (24) are contacted by means of connecting wires (32) and the connecting wires (32) are attached to the surface of the light-conducting plate (12), the connecting wires (32) being connected by means of a joining and/or adhesive connection are attached to the light-conducting plate (12) at least in certain areas. Lighting device (10) according to one of the preceding claims, wherein the lighting device (10) has additional lighting means (38) which are arranged in or on the lighting means carrier (16), wherein in the region of the additional lighting means (38) there are no recesses ( 14) and/or in particular no covers (26) are provided. Lighting device (10) according to any one of the preceding claims, wherein the recesses (14) each have a radiation opening (15) on only one side in the area of a base area and the recesses (14) are distributed over the surface of the plate (12), wherein the lamps (24) each emit light directly through a radiation opening (15) into the recess (14) and circular covers (26) are attached in each case in the area of the base areas of the circular-cylindrical recesses (14), which are formed, at least in part reflecting and/or absorbing the light emitted into that recess (14) into the plate (12), wherein the cylinder axes of the recesses (14) are arranged parallel to one another and are aligned parallel to a normal (N) to the largest plane of the plate (12), wherein the plate (12) has a plurality of imperfections (34) on the first and/or second side (28) which are designed to decouple light guided in the plate (12) and the imperfections (34) form repeating patterns, on the second side (30) a plate-shaped illuminant support (16) is attached, which comprises light-reflecting and/or reflective material, the illuminants (24) are arranged on circuit boards (22), the circuit boards being located in depressions (20) of the illuminant support ( 16) are arranged and contacted by means of connecting wires (32) and the connecting wires (32) are attached at least in regions to the surface of the illuminant carrier (16) by means of a joint and/or adhesive connection. Lighting device (10) according to one of the preceding claims, wherein the plate (12) has a central cut-out which is peripherally delimited by the material of the plate (12). Method for producing a lighting device (10) according to one of the preceding claims, in which the outer contour of the lighting device (10), the arrangement of the recesses (14) and/or one or more cutouts in the lighting device by means of a computer program, in particular in a web interface, are defined and then the outer contour of the lighting device (10), the arrangement of the recesses (14) and / or the one or more Cutouts are made in the lighting device, in particular automatically. Lighting device (10) with - a light-conducting plate (12) which comprises a first side (28) and a second side (30) opposite the first side (28), - a plurality of recesses (14) introduced into the plate (12) for coupling light into the plate (12), - a plurality of illuminants (24), each of which emits light into one of the recesses (14), and - an illuminant carrier (16), in particular in the form of a plate, attached to the second side (30), whereby the lamps (24) are contacted directly or indirectly by means of connection wires (32) and the connection wires (32) are attached to the lamp support (16) and/or to the light-conducting plate (12), the connection wires (32) being connected in particular by means of a joint - and / or adhesive bond are attached at least partially to the illuminant support (16) and / or the light-conducting plate (12).

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