Lamp with decorative layer and light source matrix and related control method

Abstract

The present invention relates to a lamp, comprising: a matrix of controllable light sources; a control unit connected to the light sources; a translucent decorative layer, the decorative layer having an incident surface and a lamp surface, so that light falling on the incident surface with an incident light density distribution reaches the lamp surface so as to be emitted with an exit light density distribution with respect to the lamp surface, wherein the decorative layer has a transmittance that varies depending on the position of the lamp surface, and the transmittance has at least one or more at least local transmittance minima along a first curve located in the lamp surface, wherein the control unit is formed to control the light source so that the incident light density distribution has one or more at least local incident light density maxima along a second curve located in the incident surface, the second curve is associated with the first curve due to optical coupling, and the one or more at least local incident light density maxima are respectively associated with one of the transmittance minima due to the optical coupling between the incident surface and the lamp surface.

Description

Technical Field

[0001] The invention relates to a lamp, in particular for a motor vehicle. Background Art

[0002] Such lamps are used in motor vehicles as room lighting (also referred to as ambient lighting, depending on the light intensity) in order to make it easier for the occupants to orient themselves in the motor vehicle in the dark. In this case, the lamps are used as ambient lighting with a lower light intensity or alternatively as indirect lighting in order to illuminate the driver's surroundings, such as the area of ​​the door panels, the center console or the instrument panel. The aim here is to give the driver a visual orientation aid without the driver being dazzled by the light source itself or by light reflected from the interior surfaces of the vehicle interior. At the same time, it is desirable that the lamp has a visually attractive surface when the lighting device is switched off, which surface is not visible in particular in front of the decoration surrounding the lamp, which is generally referred to as the "vanishing effect". In previous solutions in which the decoration extends over the light exit surface of the lamp, there is a risk that when the light source is switched on, the appearance of the lamp surface is less attractive or the lighting effect is ineffective due to the optical image of the decoration. Summary of the invention

[0003] Against this background, a solution is needed in which a luminaire is provided which is optically improved both in the switched-on state and in the switched-off state. This object is achieved by a luminaire according to claim 1. Likewise advantageous uses and corresponding methods are the subject matter of the parallel claims. Advantageous embodiments are the subject matter of the dependent claims. It should be noted that the features specified individually in the claims can be combined with one another in any technically meaningful manner and represent further embodiments of the invention. The description, in particular in conjunction with the drawings, additionally characterizes and details the invention.

[0004] The invention relates to a luminaire having a plurality of light sources arranged in a matrix, for example a plurality of light emitting diodes, preferably a plurality of organic or inorganic micro-light emitting diodes, still more preferably organic micro-light emitting diodes integrated into a foil structure.

[0005] The lamp of the present invention has a translucent decorative layer. According to the present invention, a control unit is provided, which is used to selectively control the light source. By selective control, the light of the light source has an adjustable incident light density distribution that varies depending on the position. According to the present invention, a translucent decorative layer is also provided, which extends on the matrix of the light sources. The decorative layer forms an incident surface and a lamp surface facing an observer when the lamp is arranged as intended. The incident surface is arranged to face the light source so as to be backlit by the light source. Due to the transparency of the decorative layer, the incident surface and the exit surface are optically coupled, that is, the light falling on the incident surface with the incident light density distribution emerges from the lamp surface with the exit light density distribution, wherein local reflection, absorption, refraction, filtering, focusing, etc. on the light path in the decorative surface provides a change of the incident light density distribution to the exit light density distribution.

[0006] As a unique feature of the present invention, the translucent decorative layer has a transmittance for the light of the light source that penetrates the decorative layer, which is generated due to the structure and / or decoration of the decorative layer, relative to the position of the lamp surface and thus varies in position, which also results from the optical influence within the decorative layer described previously. According to the present invention, the transmittance has at least one or more at least local transmittance minima along a first curve located in the lamp surface. In other words, the transmittance has a fluctuation width in the first curve at the position involved, which is significantly different from zero in absolute value and at least local transmittance minima should be determined along this first curve. The term "at least locally" should be understood to mean that the corresponding extreme value (maximum or minimum) can be not only a local extreme value but also an absolute extreme value. The decorative layer is preferably formed so that the optical transmittance varies along a plurality of first curves and each curve has a plurality of local minimum transmittance positions. In other words, the decoration or the structure has a smaller transmittance than the direct surrounding environment. For example, these locations are produced by density fluctuations in the material of the decorative layer and / or density fluctuations of the surface coating of the decorative layer and / or by thickness fluctuations of the decorative layer (for example due to embossing in the surface of the decorative layer).

[0007] According to the present invention, the control unit is also formed to control the light source so that the second curve of the incident light density distribution, which is associated with the first curve due to light coupling and is located in the incident surface, has one or more at least local incident light density maxima, and the one or more at least local incident light density maxima are respectively associated with one of the transmittance minima due to the optical coupling between the incident surface and the lamp surface.

[0008] In other words, those positions of the local minimum transmittance of the decorative layer are associated with those positions with the maximum incident light density, which in the simplest construction of the decorative layer is a purely positional overlap, but is not necessarily the case according to the invention, since internal light refraction in the decorative layer may lead to deviations, for example. That is, with regard to the light propagation of the light source, at positions on the incident surface corresponding to positions of low light transmittance of the decorative layer, the incident light density distribution has a higher light density in order to compensate for the lower light transmittance at this position when the light passes through the decorative layer.

[0009] The incident light density distribution is preferably set by the control unit so that it has local incident light density maxima in the incident surface along a plurality of second curves among the second curves, and the local incident light density maxima are respectively associated with transmittance minima of one of the relevant first curves.

[0010] Through the solution of the present invention, a more balanced, that is, more uniformly distributed, light distribution is achieved on the lamp surface when the light source is turned on, so that the decoration or structure of the decorative layer optically enters the background when the light source is turned on, and at the same time can show its visual appearance in a manner that is not hindered by the measures of the present invention and is not disturbed by it when the light source is turned off.

[0011] According to a preferred design, one or more transmittance maxima are also provided along the first curve, wherein the transmittances are respectively at least local maxima, wherein one or more at least local incident light density minima are provided along the second curve, and the one or more at least local incident light density minima are respectively associated with one of the transmittance maxima due to the optical coupling between the incident surface and the luminaire surface. In this way, a more uniform light distribution can be achieved on the luminaire surface, because a particularly high light intensity is provided at the position of the maximum light transmittance of the decorative layer. For example, a light density fluctuation of no more than 20%, preferably no more than 10%, is achieved on the entire light surface.

[0012] As mentioned previously, in a simple and preferred design of the lamp and in particular the decorative layer (in which the incident surface is arranged parallel to the lamp surface), the positions of the maximum incident light density in the vertical projection onto the lamp surface respectively correspond to the positions of the minimum transmittance and / or the positions of the minimum incident light density in the vertical projection onto the lamp surface respectively correspond to the positions of the maximum transmittance.

[0013] According to a preferred design of the lamp, the second maximum fluctuation width of the incident light density distribution along the second curve is greater than the first maximum fluctuation width of the exiting light density distribution along the first curve and is less than 50% of the last-mentioned first maximum fluctuation width, and more preferably less than 30%.

[0014] The light source and the control unit are preferably further configured to generate light having an incident color value distribution that varies depending on a position by selectively controlling the light source, so that the light on the luminaire surface has an exit color value distribution that varies depending on a position. Here, the control unit controls the light source so that a fourth maximum fluctuation width of the incident color value distribution along the second curve is greater than a third maximum fluctuation width of the exit color value distribution along the first curve.

[0015] For example, the structure of the decorative layer is a so-called carbon structure, such as is produced in the case of carbon composite materials. The decorative layer preferably has a structure and / or a decoration, which respectively has a natural structure or an imitation of a natural structure, such as a solid wood particle board.

[0016] Preferably, the decorative layer has a light layer for imaging that imitates the appearance and a surface pressing portion with holes or embossings extending synchronously with the light layer. The solid wood veneer has a layer thickness of several tens of μm, for example, so as to be translucent. The decorative layer can be formed as a single layer or multiple layers. At least one layer is preferably a diffuser layer. Preferably, it is a foil layer structure, that is, a layer structure having at least one layer formed by foil.

[0017] The optical transmittance that varies depending on position is preferably formed by surface processing such as laser ablation and / or surface coating such as printing of the decorative layer.

[0018] According to another design, the positionally variable optical transmittance is achieved by printing the decorative layer, such as lenticular printing. Preferably, only the incident surface of the decorative layer facing the light source is printed. For example, the printing is performed by an inkjet printing method, a digital printing method, or a lithographic printing method. The corresponding printing method has an accuracy of 50 μm or better, for example.

[0019] According to a preferred design, the lamp surface only forms a sub-surface of a surface of the decorative layer facing the observer, that is, the surface of the decorative layer exceeds the lamp surface in at least one direction.

[0020] The lamp preferably further includes a camera for detecting the outgoing light density distribution. Here, the control unit is configured to set the incident light density distribution based on the outgoing light density distribution detected by the camera.

[0021] The invention furthermore relates to the use of a lamp according to one of the above-mentioned embodiments in a motor vehicle.

[0022] The present invention further relates to a method for controlling a lamp, the method comprising the following steps. In the providing step, a lamp in one of the above-mentioned embodiments is provided. The provided lamp has the following features. The lamp has a plurality of light sources arranged in a matrix, for example a plurality of light-emitting diodes, preferably a plurality of organic or inorganic micro-light-emitting diodes, and still more preferably organic micro-light-emitting diodes integrated into a foil layer structure. The provided lamp has a translucent decorative layer. According to the present invention, a control unit is provided, which is used to selectively control the light source. Through the selective control, the light of the light source has an adjustable incident light density distribution that varies depending on the position. According to the present invention, a translucent decorative layer extending on the matrix of the light source is also provided. The decorative layer of the provided lamp forms an incident surface and a lamp surface. The incident surface is arranged to face the light source so as to be backlit by the light source. Due to the transparency of the decorative layer, the incident surface and the exit surface are optically coupled, that is, light falling on the incident surface with the incident light density distribution exits from the lamp surface with the exit light density distribution, wherein, for example, local reflection, absorption, refraction, filtering, focusing, etc. on the light path in the decorative surface provides a change from the incident light density distribution to the exit light density distribution.

[0023] As a unique feature of the invention, the translucent decorative layer provided has a transmittance for the light of the light source that penetrates the decorative layer, which is generated due to the structure and / or decoration of the decorative layer, relative to the position of the luminaire surface and thus varies in position, which also results from the optical influences within the decorative layer described above. According to the invention, the transmittance has at least one or more at least local transmittance minima along a first curve located in the luminaire surface. In other words, the transmittance has a fluctuation width in the first curve at the relevant position, which is clearly not equal to zero in absolute value and an absolute transmittance minimum or a local transmittance minimum is to be determined along this first curve. The decorative layer is preferably formed so that the optical transmittance varies along a plurality of first curves and each curve has a position of a local or absolute minimum transmittance. In other words, the decoration or the structure has a lower transmittance than the immediate surroundings. For example, these positions are generated by density fluctuations in the material of the decorative layer and / or density fluctuations of the surface coating of the decorative layer and / or by thickness fluctuations of the decorative layer (for example due to embossing in the surface of the decorative layer).

[0024] According to the present invention, the light source is controlled by the control unit so that the second curve of the incident light density distribution, which is associated with the first curve due to light coupling and is located in the incident surface, has one or more at least local incident light density maxima, and the one or more at least local incident light density maxima are respectively associated with one of the transmittance minima due to the optical coupling between the incident surface and the lamp surface.

[0025] In other words, those positions of the local minimum transmittance of the decorative layer are associated with those positions with the maximum incident light density, which in the simplest construction of the decorative layer is a purely positional overlap, but is not necessarily the case according to the invention, since internal light refraction in the decorative layer may lead to deviations, for example. That is, with regard to the light propagation of the light source, at positions on the incident surface corresponding to positions of low light transmittance of the decorative layer, the incident light density distribution has a higher light density in order to compensate for the lower light transmittance at this position when the light passes through the decorative layer.

[0026] The incident light density distribution is preferably set by the control unit so that it has local incident light density maxima in the incident surface along a plurality of second curves among the second curves, and the local incident light density maxima are respectively associated with transmittance minima of one of the relevant first curves.

[0027] Through the solution of the present invention, a more balanced, that is, more uniformly distributed, light distribution is achieved on the lamp surface when the light source is turned on, so that the decoration or structure of the decorative layer optically enters the background when the light source is turned on, and at the same time can show its visual appearance in a manner that is not hindered by the measures of the present invention and is not disturbed by it when the light source is turned off.

[0028] According to a preferred design of the method, one or more transmittance maxima are also provided along the first curve, wherein the transmittances are respectively at least local maxima. The light source is controlled by the control unit so that one or more at least local incident light density minima are provided along the second curve, and the one or more at least local incident light density minima are respectively associated with one of the transmittance maxima due to the optical coupling between the incident surface and the luminaire surface. In this way, a more uniform light distribution can be achieved on the luminaire surface, because a particularly high light intensity is provided at the position of the maximum light transmittance of the decorative layer. For example, a light density fluctuation of no more than 20 percent, preferably no more than 10 percent, is achieved on the entire light surface.

[0029] As mentioned previously, in the simple and preferred design of the provided lamp and in particular the provided decorative layer (in which the incident surface is arranged parallel to the lamp surface), the positions of the maximum incident light density in the vertical projection onto the lamp surface respectively correspond to the positions of the minimum transmittance and / or the positions of the minimum incident light density in the vertical projection onto the lamp surface respectively correspond to the positions of the maximum transmittance.

[0030] According to a preferred design of the method, the second maximum fluctuation width of the incident light density distribution along the second curve is greater than the first maximum fluctuation width of the exiting light density distribution along the first curve and is less than 50% of the last-mentioned first maximum fluctuation width, more preferably less than 30%.

[0031] The control unit and light source of the provided lamp are preferably further configured to generate light having an incident color value distribution that varies depending on a position by selectively controlling the light source, so that the light on the lamp surface has an exit color value distribution that varies depending on a position. In a preferred design of the method, the control unit controls the light source so that a fourth maximum fluctuation width of the incident color value distribution along the second curve is greater than a third maximum fluctuation width of the exit color value distribution along the first curve.

[0032] The provided lamp preferably also has a camera for detecting the exit light density distribution. The method thus comprises a step of detecting the exit light density distribution by means of the camera, and a step of controlling the light source by the control unit based on the exit light density distribution detected by the camera, thereby setting the incident light density distribution. The method is applied, for example, to the manufacture of lamps in order to calibrate the incident light density distribution. For example, the calibration step is to control the light source so as to produce a uniform calibrated incident light density distribution and simultaneously perform a detection of the associated exit light density distribution, which enables the acquisition of the spatial distribution of the transmittance. The spatial distribution of the transmittance is used to subsequently determine and control the light source with the incident light density distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The invention is explained in detail with reference to the following drawings. The drawings are to be understood as being merely exemplary and represent only preferred embodiments. In the drawings:

[0034] Figure 1 A schematic perspective view showing an embodiment of a lamp 1 according to the invention;

[0035] Figure 2 An illustrative representation of the correlation of the incident light density L, the output light density L′ and the transmittance T which vary in position with respect to the spatial curves s1 and s2 , respectively, is shown. DETAILED DESCRIPTION

[0036] Figure 1 An embodiment of a luminaire 1 according to the invention is shown. The luminaire 1 has an array 2 of micro-light-emitting diodes as light sources 3. A translucent decorative layer 5 is also provided, which extends over the array 2 of light sources 3. The light sources 3 are electrically conductively connected to a control unit 4, which allows selective control of the light sources 3, i.e., selective control of the light intensity of each light source 3. The light generated by the light sources 3 is directed to the decorative layer 5, which is arranged with its incident surface 8 facing the light sources 3, while the surface 9 of the decorative layer 5 facing away from the incident surface 8 is arranged facing the observer B in the case of the intended arrangement of the luminaire 1. Under corresponding control of the control unit 4, the light of the light source 3 falls on the incident surface 8 with an incident light density distribution L to be determined on the incident surface 8 and which varies in position. Since the decorative layer 5 is formed to be translucent to transparent, it forms a light conductor, so that the light is coupled into the decorative layer 5 in the region of the incident surface 8, so as to penetrate the decorative layer and on the opposite luminaire surface 7, which is only a sub-surface of the surface 9 of the decorative layer 5 facing the observer B. On the luminaire face 7, the light is emitted in the direction of the observer B with an emission light density distribution L'. Due to the coating and / or the surface pressing, the decorative layer 4 has a decoration 6 on its entire surface 9, wherein the decoration 6 realizes a transmittance T that varies in position on the luminaire face 7. Here, the first curve s1 represents the entire luminaire face 7. Due to the relative orientation between the incident surface 8 and the luminaire face 7 and the uniform formation of the decorative layer 5 except for the decoration 6, the light incident along the second curve s2 is emitted at the position of the vertical projection of the first curve s1 onto the luminaire face 7. As shown in FIG. Figure 2 As shown, the decoration 6 realizes a transmittance T with a local transmittance minimum Tmin and a local transmittance maximum Tmax to be determined along the first curve S1, and the local transmittance minimum and the local transmittance maximum can also be absolute maximum or minimum values, respectively. According to the present invention, the light source 3 of the matrix 2 is controlled by the control unit 4 so that the incident light density distribution L has a local maximum, namely the so-called incident light density maximum Lmax (which can also be an absolute maximum) at a position of the second curve s2 located in the incident surface 8 corresponding to the position of the transmittance minimum Tmin due to the special optical coupling between the incident surface 8 and the luminaire surface 7.

[0037] Correspondingly, at the position of the second curve s2 located in the incident surface 8 corresponding to the position of the transmittance maximum value Tmax due to the special optical coupling between the incident surface 8 and the luminaire surface 7, the incident light density distribution L has a local minimum, namely the so-called incident light density minimum value Lmin (which can also be an absolute minimum value). This results in that the exit light density distribution L' to be determined along the first curve s1 in the luminaire surface 7 has a maximum fluctuation width ΔL', which is smaller than the maximum fluctuation width ΔL of the incident light density distribution L in absolute value, wherein the fluctuation width is obtained as the absolute value difference between the corresponding absolute extreme values ​​(absolute maximum value and absolute minimum value) of the exit light density distribution L' along the first curve s1 and the incident light density distribution L along the second curve s2, as shown in FIG. Figure 2 shown.

[0038] Another design scheme can also be envisaged, in which the control unit 4 and the light source 3 are also formed to generate light having an incident color value distribution that varies depending on the position on the incident surface 8 by selectively controlling the light source 3, wherein the light emitted by the luminaire surface 7 has an exit color value distribution that is determined on the luminaire surface 7 and varies depending on the position, and the exit color value distribution is, for example, based on a color value offset achieved by the decorative layer 5, and wherein the control unit 4 controls the light source 3 so that the fourth maximum fluctuation width of the incident color value distribution along the second curve s2 is greater than the third maximum fluctuation width of the exit color value distribution along the first curve s1.

[0039] Overall, the control of the light source 3 according to the invention provides for a homogenization of the brightness (= illumination density) and of the color values ​​of the light emerging on the luminaire surface 7, despite the disruptive effect of the decoration 6 of the decorative layer 5 on the uniform light propagation. In one embodiment, the calibration control can be performed by means of a camera 10, wherein the emerging light density distribution L' is detected by means of the camera 10, and the light source 3 is controlled by the control unit 4 based on the emerging light density distribution L' detected by the camera 10, so that the incident light density distribution (L) is set. For example, an on-the-fly adaptation can be performed. In another embodiment, a calibration step can be performed by means of the camera 10, wherein the emerging light density distribution L' is determined under a uniform calibration incident light density distribution on the incident surface 8, so that a positionally varying transmittance T is thereby obtained in the calibration step. In the subsequent, intended use of the luminaire 1, the transmittance T thus obtained is used to determine the incident light density distribution L, so that the decoration 6 essentially disappears when the luminaire 1 is switched on.

Claims

1. A lamp (1), comprising: A matrix (2) of controllable light sources (3) for generating light; a control unit (4) connected to the light source (3) so as to generate light having an adjustable, position-dependent incident light density distribution (L) by selectively controlling the light source (3); A translucent decorative layer (5) extending on the matrix (2) of the light source (3), the decorative layer having an incident surface (8) facing the light source (3) and a luminaire surface (7) facing an observer (B) and optically coupled to the incident surface (8), so that light falling on the incident surface (8) with the incident light density distribution (L) reaches the luminaire surface (7) to be emitted with an exit light density distribution (L') with respect to the luminaire surface (7), wherein the decorative layer (5) has a transmittance (T) for the light that varies depending on the position of the luminaire surface (7) due to a structure and / or a decoration (6), and the transmittance is along a portion of the luminaire surface located at the luminaire surface. (7) has at least one or more at least local transmittance minima (Tmin), wherein the control unit (4) is formed to control the light source (3) so that the incident light density distribution (L) has one or more at least local incident light density maxima (Lmax) along a second curve (s2) located in the incident surface (8), the second curve being associated with the first curve (s1) due to optical coupling, the one or more at least local incident light density maxima being respectively associated with one of the transmittance minima (Tmin) due to the optical coupling between the incident surface (8) and the luminaire surface (7); And wherein one or more transmittance maxima (Tmax) are also arranged along the first curve (s1), wherein the transmittance (T) is respectively at least a local maximum, and the incident light density distribution (L) has one or more at least local incident light density minima (Lmin) along the second curve (s2), and the one or more at least local incident light density minima are respectively associated with one of the transmittance maxima (Tmax) due to the optical coupling between the incident surface (8) and the luminaire surface (7).

2. The luminaire (1) according to claim 1, wherein the incident surface (8) is arranged parallel to the luminaire surface (7), and the position of the maximum incident light density (Lmax) in the vertical projection onto the luminaire surface (7) corresponds to the position of the minimum transmittance (Tmin) and / or the position of the minimum incident light density (Lmin) in the vertical projection onto the luminaire surface (7) corresponds to the position of the maximum transmittance (Tmax).

3. The luminaire (1) according to claim 1, wherein a second maximum fluctuation width (ΔL) of the incident light density distribution (L) along the second curve (s2) is greater than a first maximum fluctuation width (ΔL') of the exit light density distribution (L') along the first curve (s1).

4. The luminaire (1) according to claim 1, wherein the control unit (4) and the light source (3) are further formed to generate light having an incident color value distribution that varies depending on the position on the incident surface (8) by selectively controlling the light source (3), and the light emitted from the luminaire surface (7) has an exit color value distribution that is determined on the luminaire surface (7) and varies depending on the position, wherein the control unit (4) controls the light source (3) so that a fourth maximum fluctuation width of the incident color value distribution along the second curve (s2) is greater than a third maximum fluctuation width of the exit color value distribution along the first curve (s1).

5. The luminaire (1) according to claim 1, wherein the decorative layer (5) has a structure and / or a decoration (6).

6. The lamp (1) according to claim 5, wherein the decorative object (6) has a natural structure or an imitation of a natural structure.

7. The luminaire (1) according to claim 6, wherein the natural structure is a solid wood veneer.

8. The luminaire (1) according to claim 6, wherein the imitation of the natural structure is a solid wood particle board.

9. The luminaire (1) according to claim 1, wherein the optical transmittance (T) that varies depending on the position is formed by surface processing and / or surface coating, such as printing, of the decorative layer (5).

10. The luminaire (1) according to claim 1, wherein the luminaire face (7) is only a sub-surface of a surface (9) of the decorative layer (5) facing the observer (B).

11. The luminaire (1) according to claim 1, wherein the matrix (2) of light sources (3) is an array of organic or inorganic micro-light emitting diodes.

12. The luminaire (1) according to claim 1, further comprising a camera (10) for detecting the exit light density distribution (L'), and wherein the control unit (4) is formed to set the incident light density distribution (L) based on the exit light density distribution (L') detected by the camera (10).

13. Use of a lamp (1) according to any of the preceding claims 1 to 12 in a motor vehicle.

14. A method for controlling a lamp: providing a lamp (1), the lamp having: A matrix (2) of controllable light sources (3) for generating light; a control unit (4) connected to the light source (3), the control unit being designed to generate light having an adjustable, position-dependent incident light density distribution (L) by selectively controlling the light source (3); A translucent decorative layer (5) extending on the matrix (2) of the light sources (3), the decorative layer having an incident surface (8) facing the light sources (3) and a luminaire surface (7) facing an observer (B) and optically coupled to the incident surface (8), so that light falling on the incident surface (8) with the incident light density distribution (L) reaches the luminaire surface (7) to be emitted with an exit light density distribution (L') with respect to the luminaire surface (7), wherein the decorative layer (5) has a transmittance (T) for the light that varies depending on the position of the luminaire surface (7) due to a structure and / or a decoration (6), and the transmittance varies along a direction located at the luminaire surface (7). A first curve (s1) in the luminaire surface (7) has at least one or more at least local transmittance minimum values ​​(Tmin); the light source (3) is controlled by the control unit (4) so ​​that the incident light density distribution (L) has one or more at least local incident light density maxima (Lmax) along a second curve (s2) located in the incident surface (8), the second curve being associated with the first curve (s1) due to optical coupling, and the one or more at least local incident light density maxima being associated with one of the transmittance minimum values ​​(Tmin) respectively due to the optical coupling between the incident surface (8) and the luminaire surface (7); And one or more transmittance maxima (Tmax) are also arranged along the first curve (s1), wherein the transmittance (T) is respectively at least a local maximum, and the control unit (4) controls the light source (3) so that the incident light density distribution (L) has one or more at least local incident light density minima (Lmin) along the second curve (s2), and the one or more at least local incident light density minima are respectively associated with one of the transmittance maxima (Tmax) due to the optical coupling between the incident surface (8) and the luminaire surface (7).

15. The method according to claim 14, wherein the incident surface (8) is arranged parallel to the lamp surface (7), and the position of the maximum incident light density (Lmax) in the vertical projection onto the lamp surface (7) corresponds to the position of the minimum transmittance (Tmin) and / or the position of the minimum incident light density (Lmin) in the vertical projection onto the lamp surface (7) corresponds to the position of the maximum transmittance (Tmax).

16. The method according to claim 14, wherein the control unit (4) controls the light source (3) so that a second maximum fluctuation width (ΔL) of the incident light density distribution (L) along the second curve (s2) is greater than a first maximum fluctuation width (ΔL') of the exit light density distribution (L') along the first curve (s1).

17. The method according to claim 14, wherein the control unit (4) and the light source (3) are further formed to generate light having an incident color value distribution that varies depending on the position on the incident surface (8) by selectively controlling the light source (3), and the light emitted from the luminaire surface (7) has an exit color value distribution that is determined on the luminaire surface (7) and varies depending on the position, wherein the control unit (4) controls the light source (3) so that a fourth fluctuation width of the incident color value distribution along the second curve (s2) is greater than a third fluctuation width of the exit color value distribution along the first curve (s1).

18. The method according to claim 14 further comprises the following steps: providing a camera (10); detecting the outgoing light density distribution (L') by means of the camera (10), and controlling the light source (3) by the control unit (4) based on the outgoing light density distribution (L') detected by the camera (10), thereby setting the incident light density distribution (L).

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