LIGHTING DEVICE FOR EMITTING LIGHT

Abstract

Lighting device (10) for emitting light, comprising: - a light source (12, 14, 16, 18) for emitting source light (20), and - an adjustable optical unit (22) which is designed to provide the light to be emitted by the lighting device (10) using the source light (20), wherein the light source (12, 14, 16, 18) is designed to adjust a geometric extent of a light emission surface (26) of the light source (12, 14, 16, 18) emitting the source light (20) and / or a radiation behavior and / or a spectral property of the light source (12, 14, 16, 18) with respect to the source light (20) depending on a light entrance pupil (24) and / or an acceptance angle of the optical unit (22) for the source light (20), characterized in that the light source (12, 14, 16, 18) is designed to adjust the light emission surface (26) and / or the radiation behavior and / or the spectral property depending on a source control signal and is further designed to adjust a luminous flux of the source light (20) independently of the light emission surface (26) and / or the radiation behavior, that the light source (12, 14, 16, 18) has an adjustable source optics unit (32, 34, 36, 38) for adjusting the light emission surface (26) and / or the radiation behavior, that the source optics unit (32, 34, 36, 38) has at least one lens (40, 42, 44) arranged to be movable along an optical axis of the emitted source light (20), at least one adjustable mirror element (46, 54, 56) and / or at least one adjustable diaphragm unit, and the source optics unit (32, 34, 36, 38) further has an adjustable light scattering unit (48).

Description

[0001] The invention relates to a lighting device for emitting light, comprising a light source for emitting source light and an adjustable optical unit configured to provide the light to be emitted by the lighting device using the source light. Furthermore, the invention also relates to a method for operating a lighting device that emits light, comprising the steps of: emitting source light by means of a light source, and providing the light to be emitted by the lighting device by means of an adjustable optical unit that utilizes the source light.

[0002] Generic lighting devices and methods for their operation are extensively known in the prior art, so that separate written documentation is not required. Lighting devices serve to provide light in a predeterminable manner for at least partially illuminating a room or a surface. For this purpose, the lighting device has at least one light source by means of which electrical energy can be converted into light emission. The lighting device is therefore usually connected to an electrical energy source that can provide electrical energy for the intended operation of the lighting device, in particular its light source.The lighting device itself can be used in a variety of ways, for example to provide outdoor lighting, indoor lighting within a room, but also with regard to a technical application, for example in the context of stage lighting, workplace lighting, in particular lighting in an operating room, medical and therapeutic lighting, lighting for horticulture and many more.

[0003] DE 10 2012 224 345 A1 discloses a vehicle lighting device having at least one semiconductor light source and at least one downstream optical element, wherein the at least one optical element is positionally adjustable.

[0004] JP 2005-158699 A discloses an LED lighting device and a headlight using a light emitting diode (LED).

[0005] DE 195 03 675 A1 discloses an optical transmission system and a method for light emission, the system comprising a laser oscillator, an optical fiber for propagating the laser beam emitted by the laser oscillator, a condenser lens for concentrating the laser beam from the laser oscillator into the optical fiber, a first lens for generating images with an aberration from the laser beam emerging from the optical fiber, a mask in a position having a predetermined light intensity distribution from the positions of the images generated by the first lens, and a second lens for forming the image passing through the mask on the object to be irradiated.

[0006] DE 20 122 782 U1 discloses an illumination device comprising a laser emitting a light beam directed onto a microstructured optical element which spectrally broadens the light of the laser, wherein the laser and the microstructured optical element are combined to form a module.

[0007] DE 10 2013 222 430 A1 discloses an illumination device and a method for generating light by means of a wavelength conversion arrangement and a band-stop filter, as well as a method for providing a band-stop filter.

[0008] DE 10 2013 215 054 A1 discloses an illumination device with a phosphor wheel and an excitation beam source.

[0009] In addition to the light source for emitting source light, a generic lighting device can also comprise the adjustable optical unit, which is designed to provide the light to be emitted by the lighting device using the source light. Typically, the light source is a fixed unit of the lighting device that can be adjusted during normal operation with regard to the emitted luminous flux and, if necessary, also with regard to a spectral light distribution. However, other characteristic properties of the light source, such as the etendue as a conserved quantity, cannot be changed at all or are generally not changeable or can only be changed with great difficulty, such as the beam angle, color, the size of the light-emitting surface, and / or the like.

[0010] Adjusting the light emitted by the lighting device can usually only be achieved with the optical unit. For this purpose, the optical unit can comprise a wide variety of elements for influencing the source light, for example, refractive elements such as lenses, prisms, fly-eyes, microlens arrays, combinations thereof, or the like; mirrors, for example, micromirrors, DMDs (Digital Micromirror Devices), MEMS (Micro-Electromechanical Mirror Systems), combinations thereof, or the like; a wide variety of apertures; and optically effective filter elements, for example, color filters, polarization filters, LCDs (Liquid Crystal Displays), dichroic filters, holographic elements, and / or the like; as well as other optical elements such as beam splitters, beam combiners, phase-shifting elements, and combinations thereof.Of course, the aforementioned different elements can also be combined in any number and in any way in the optical unit in order to shape the source light into the emitted light in the desired manner.

[0011] High-quality lighting devices, particularly when intended for specific applications, have adjustment options in the area of ​​the optical unit to allow the light emitted by the lighting device to be adjusted as needed. For this purpose, the optical unit can comprise an adjustment device or the like with which the aforementioned elements of the optical unit can be suitably positioned and / or aligned to generate the light to be emitted from the source light. Such an adjustment device can be designed to manually adjust the optical unit by having corresponding adjustment elements that can be manually operated.Furthermore, it is of course possible for the adjustment device to also provide at least partially automated adjustment options, for example by supplying one or more suitable control signals to the adjustment device, whereupon the adjustment device adjusts the adjustable elements of the optical unit as desired. Such configurations are used, for example, in particular in the field of stage lighting, specifically for example with moving heads, also known as head-moving spotlights, in which structured optical apertures such as gobos or the like are to be adjusted. However, the adjustment of the optical unit can also comprise a one-time adjustment, in particular, for example, comprise a non-adaptive adjustment.

[0012] Lighting devices of this type are used, among other things, in video projection systems or entertainment applications. Video projection applications include applications in which lighting devices are used for digital video projectors. In entertainment applications, the lighting devices are used, for example, for effect lighting technology or similar. Such lighting devices, which can be moved quickly in several degrees of freedom in order to create specific lighting effects and lighting backdrops, are also referred to as moving heads or similar. Moving heads are therefore particularly freely movable multifunctional spotlights, for example in the field of theater and event technology.

[0013] However, such lighting devices are not only used in the field of moving spotlights. They can also be designed to provide stationary light output in a predefined manner, for example, by coupling light into a fiber optic cable or similar. The conditions under which the lighting device is designed to couple the light into the fiber optic cable can vary considerably depending on local conditions. To achieve sufficient light coupling into the fiber optic cable, it is therefore desirable to be able to adjust the light output of the lighting device appropriately.

[0014] Even if the state of the art has proven itself, disadvantages still arise. For example, it is disadvantageous in lighting technology that the light provided by the light source cannot always be optimally used by the optical unit. This is evident, for example, in moving heads, namely in relation to varying aperture settings. In this case, the light source should ideally be designed in such a way that it can provide sufficient luminous flux and beam cross-section for the largest adjustable aperture, so that the aperture can be completely filled with light. However, with a very small aperture, a light source designed in this way results in a large proportion of the light being shielded by the aperture, for example by the light being reflected or absorbed by the aperture or the like.In particular, high-performance lighting devices can experience large power losses when absorbing light that does not penetrate the aperture, which can lead to high thermal stress on the lighting device.

[0015] In the case of coupling light into a light guide, it is evident that even with the most favorable setting of the optical unit, optimal light coupling into the light guide often cannot be achieved, in particular because a source size and / or a numerical aperture can usually not be adjusted independently.

[0016] The problems that can occur will be further explained using an example of an effect light spotlight similar to a moving head as a lighting device.

[0017] Effect lights typically have an optical unit with a multitude of optical elements, which can usually be changed or modified automatically and at very short intervals, for example, in fractions of a second. For this purpose, the lighting system can be equipped with a digital multiplex (DMX) control system. DMX refers to a digital control protocol used in stage and event technology to control dimmers, "intelligent" spotlights, moving heads, and effects devices. DMX is at least partially covered by standards, for example, DIN 56930-2 or similar.Examples of such adjustable optical elements of this type include gobos with different designs and / or diameters for forming special light profiles, frosting elements by means of which a light beam can be widened and blurred, zoom elements that enable different light beam diameters and / or the like.

[0018] Many of these elements can also be operated in combination with one another. Depending on which of these elements is currently activated, it would be desirable for the light source to have a correspondingly adapted source size that is as optimal as possible with regard to imaging properties and the efficiency of the overall system consisting of the light source and optical unit.

[0019] For example, in the case of a gobo with a large aperture and / or a zoom setting for a large beam diameter, a light source with a large source diameter would be optimal because the low luminance requirements of the light source allow for a larger source diameter. This can provide advantages for the thermal load of the light source and generally also enable higher light source efficiency.

[0020] In contrast, however, high luminance levels are required to achieve sufficient system efficiency and functionality for gobos with very small structures. Accordingly, the light source needs the smallest possible diameter, which results in higher thermal stress on the light source and can ultimately adversely affect its achievable service life.

[0021] Today's standard light sources generally have a fixed size. While this size can be varied using an optical telescope, it is not possible to change the luminance. Generic lighting fixtures are therefore designed according to the specific properties that are particularly important for a specific lighting fixture. Depending on the design, this can lead to efficiency losses or excessive stress on the light source and / or the lighting fixture. For example, if a gobo with a small structure requires a large portion of the source light to be absorbed by the lighting fixture, particularly in the immediate vicinity of the gobo.

[0022] The invention is therefore based on the object of specifying a generic lighting device and a method for its operation, which makes it possible to improve the efficiency and / or the service life of the lighting device.

[0023] As a solution, the invention proposes a lighting device and a method according to the independent claims.

[0024] Advantageous further training results from the characteristics of the dependent claims.

[0025] With regard to a generic lighting device, it is proposed in particular that the light source is designed to adjust a geometric extension of a light emission surface of the light source emitting the source light and / or a radiation behavior and / or a spectral property of the light source with respect to the source light depending on a light entrance pupil and / or an acceptance angle of the optical unit for the source light.

[0026] The terms light, light source, lighting device, source light and the like used here and in the following are intended to cover the entire electromagnetic spectrum, i.e. ultraviolet, visible light and infrared.

[0027] The radiation source is, for example, a light-emitting diode (LED). This can be in the form of at least one individually packaged LED or in the form of at least one LED chip containing one or more light-emitting diodes. Several LED chips can be mounted on a common substrate (“submount”) to form an LED, or they can be attached individually or together, for example, to a circuit board (e.g., FR4, metal-core circuit board, etc.) (“CoB” = chip on board). The at least one LED can be equipped with at least one separate and / or shared optics for beam guidance, for example, with at least one Fresnel lens or a collimator. Instead of or in addition to inorganic LEDs, for example based on AlInGaN, InGaN, or AlInGaP, organic LEDs (OLEDs, e.g., polymer OLEDs) can generally also be used. The LED chips can be directly emitting or have a phosphor in front of them.Here, the light-emitting component can preferably be a laser diode or a laser diode array, particularly in a LARP array. It is also conceivable to provide an OLED luminous layer or multiple OLED luminous layers or an OLED luminous region. The emission wavelengths of the light-emitting components can be in the ultraviolet, visible, and / or infrared spectral range. The light-emitting components can additionally be equipped with their own converter. For applications as a light source for vehicle headlights, the LED chips preferably emit white light in the standardized ECE white field of the automotive industry, for example, realized by a blue emitter and a yellow / green converter.

[0028] With regard to a generic method, it is proposed in particular that a geometric extension of a light emission surface of the light source emitting the source light and / or a radiation behavior and / or a spectral property of the light source with respect to the source light is adjusted depending on a light entrance pupil and / or an acceptance angle of the optical unit for the source light.

[0029] The invention is based on the finding that with a variable light source size, the light source can be better adapted to the optical properties of the optical unit, so that the use of the source light can be improved. This also applies equally to the radiation behavior. This measure also makes it possible, among other things, to optimally adjust the etendue of the light source, so that the most efficient use of the source light can be achieved. Because the light emission surface of the light source and / or the radiation behavior can be adjusted, the light source can be optimally adapted to a respective setting of the optical unit, which is determined by the light entrance pupil and / or the acceptance angle of the optical unit. The adjustability of the light source thus makes it possible to ensure that the largest possible proportion of the source light can be captured and used by the optical unit.This significantly reduces the mismatches common in the state of the art. This means not only that the light source requires less intensive use, but also that the optical unit and the lighting device as a whole require less stress during normal operation, particularly with regard to thermal stress. Furthermore, the overall efficiency of the lighting device can be improved.

[0030] The adjustability of the light-emitting surface can be provided depending on the physical design of the light source. For example, with traditional light sources such as halogen lamps, gas discharge lamps such as HMI®, HTI®, P-VIP®, or the like, it is possible to achieve an increase in luminance, albeit only to a limited extent, through a specific operating mode or through acoustic resonances. With an AC lamp, for example, a burner can be moved for a small etendue in order to exploit a hot spot in front of one of the electrodes of the AC lamp. The dependence of a spot size on an angle can be used in this case. This option can also be used with conventional lamps, as mentioned above.

[0031] It is also possible to influence the radiation pattern of the light source to a certain extent. The radiation pattern refers to the emitted light from the light source and indicates the spatial area into which the source light is emitted. The spatial area can be specified by an angle, particularly a solid angle.

[0032] This also applies analogously to the acceptance angle of the optical unit, which can be used to indicate from which spatial area the optical unit can receive source light for the further intended function of the optical unit.

[0033] In addition, the optical unit has a light entrance pupil through which the light enters the optical unit. The light entrance pupil can be defined, for example, as the image of an aperture stop formed by optical elements between the aperture stop and a respective object. The light entrance pupil is further explained, for example, in "Fundamentals of Optics," 4th edition by Jenkins and White, McGraw-Hill Publishing, 1984.

[0034] The spectral property can be a spectral distribution of the source light. This can be varied as needed. This can be achieved using suitable color filters and suitable conversion materials, which can be operated in alternating mode, for example. It can be provided that the spectral property can be adapted to the spectral acceptance of the optical unit.

[0035] In this respect, the ability of the optical unit to capture the source light is determined by the light entrance pupil and / or the acceptance angle of the optical unit. Often, both the light entrance pupil and the acceptance angle are relevant.

[0036] The invention utilizes the finding that the effects according to the invention can be achieved particularly when the light-emitting surface, in conjunction with the radiation behavior of the light source, is selected to be appropriately adapted to the light entrance pupil in conjunction with the acceptance angle. This can also result in an appropriately adapted etendue of the light source.

[0037] Through this adaptation, it can be achieved that the light can be used essentially in full during the transition from the light source to the optical unit. At the same time, it can be achieved that the functionality of the optical unit can be fully utilized by providing the source light adapted to the light entrance pupil and / or the acceptance angle of the optical unit. The invention therefore provides a variable source size of the light source, which is selected depending on an adjustment of the optical unit with regard to the light entrance pupil and the acceptance angle. This can also result in a varying adjustment of the optical unit leading to the light source also being adjusted in a suitable manner with regard to the light emission source and / or the radiation behavior. A control loop can also be provided for this purpose, via which the system can be stabilized.

[0038] According to the invention, the light source is designed to adjust the light emission area and / or the radiation behavior depending on a source control signal. The source control signal can be an electrical signal, which serves to be able to adjust the light source as desired. For example, it can be provided that in a light source based on a light-emitting diode matrix, the number of light-emitting diodes, which can be controlled with regard to light emission preferably individually or in suitably formed groups, can be controlled with regard to light emission depending on the source control signal. If the light-emitting diodes are arranged in concentric rings, for example, it can be provided that, depending on a circular light entrance pupil, only the concentric rings whose light can reach the light entrance pupil are activated for light emission.If the diameter of the light entrance pupil changes, the concentric rings can also be controlled accordingly using the source control signal.

[0039] Of course, this does not only apply to light sources constructed on the basis of light-emitting diodes, but can also be used for other light sources in general, in particular for laser-based light sources that emit source light using a phosphor or the like.

[0040] The source control signal can be provided by a control device of the lighting device. The control device of the lighting device can be used to adjust the light output in a predeterminable manner.

[0041] The control device can also serve to control the optical unit in a corresponding manner, for example, by means of an optical unit control signal, by means of which at least partially automated control of the optical unit can be achieved. Particularly advantageously, the source control signal can also simultaneously form the optical unit control signal. In this case, the control unit of the lighting device only needs to provide a single signal, which can control both the light source and the optical unit in a suitable manner.

[0042] Furthermore, it is of course possible for the light source to determine the current setting of the optical unit using a suitable light source controller and provide the source control signal itself. For this purpose, the light source controller can comprise one or more suitable sensors by means of which the setting of the optical unit can be determined. Combinations of the aforementioned configurations can also be provided.

[0043] According to the invention, the light source is designed to adjust a luminous flux of the source light independently of the light-emitting surface and / or the radiation behavior. This makes it possible to adapt the light source to a specific property of the optical unit, in particular the light entrance pupil and / or the acceptance angle. If, for example, a certain luminous flux of the lighting device is desired regardless of an adjustment of the optical unit, this can be achieved by setting the luminous flux for a small light-emitting surface to be essentially the same as for a large light-emitting surface. This is evident, for example, in the adjustment of gobos with very small openings, which, if the luminous flux were dependent on the light-emitting surface and / or the radiation behavior of the light source, could only provide a very low total luminous flux.To improve this, the luminous flux can be adjusted independently of the light-emitting area and / or the radiation behavior. With a small light-emitting area, it can therefore be provided that the luminous flux is set higher. An example of this is the light-emitting diode matrix: in a gobo with a small opening, the active light-emitting diodes of the light-emitting diode matrix can be operated with a higher current in order to achieve a desired lighting effect, even though the gobo opening is small. If, on the other hand, the gobo opening is large, a corresponding reduction in the light emission of the individual active light-emitting diodes in the light-emitting diode matrix can be provided in order to limit the lighting, for example to prevent undesirable glare or the like.Furthermore, an increase in the performance of activated, i.e., illuminated, LEDs can be achieved if a cooling function of non-activated LEDs allows for higher loads on the activated LEDs. This is, of course, not limited to the application of LEDs, but can equally be used for other light sources, particularly laser-based light sources that utilize a phosphor.

[0044] A further development provides that the light source comprises a solid-state light source, in particular a combination of the solid-state light source with a phosphor that is irradiated with light emitted by the solid-state light source, particularly preferably a combination of the solid-state light source with the phosphor, in which the source light is provided by a superposition of the light emitted by the solid-state light source and the light emitted by the phosphor. Solid-state light sources, for example, light-emitting diodes, but also laser-based light sources, superluminescent diodes (SLD), or the like, are particularly suitable for implementing the invention. Using such light sources, the light-emitting surface as well as the radiation behavior can be adjusted in a sometimes quite simple manner.In addition, these light sources open up the possibility of wide adjustment ranges with regard to the light-emitting area or light emission area and / or the radiation behavior. With conventional light sources, in contrast, the adjustment options in this regard are sometimes quite limited. It can be provided that the phosphor fully converts the light supplied by the solid-state light source. It can also be provided that only a portion of the light from the solid-state light source is supplied to the phosphor and that the light converted by the phosphor is superimposed on at least a portion of the light from the solid-state light source not supplied to the phosphor. In this variant, only a portion of the light from the solid-state light source needs to be directed onto the phosphor element and converted into full conversion.The other part of the light from the solid-state light source can be directed around the phosphor, for example by means of a mirror or the like, and then superimposed again with the conversion light from the phosphor.

[0045] The solid-state light source may comprise one or more light-emitting elements, such as light-emitting diodes, laser diodes, and / or the like. If multiple light-emitting elements are provided, the light emitted by the multiple light-emitting elements may be combined or superimposed to form the source light by means of suitable optical elements.

[0046] It is advantageous to use a phosphor in addition to the solid-state light source, which is irradiated with the light emitted by the solid-state light source and emits the source light in response. Light sources in which a laser light source is combined as a solid-state light source with a phosphor are also known, for example, as Laser Activated Remote Phosphor (LARP). This design makes it easy to provide the light-emitting area and its variation. All that is required is to expose the phosphor to the light emitted by the solid-state light source to achieve the desired light-emitting area or the desired radiation behavior. This design is particularly suitable for high luminance levels.Furthermore, the phosphor can of course be used to ensure that the source light can be provided in the desired manner with regard to its spectral properties. Suitable phosphors can include, for example, oxidic or (oxy)nitridic materials, such as garnet, orthosilicates, nitrido(alumo)silicates, nitrido-orthosilicates, or halides or halophosphates. Specific examples can include doped yttrium aluminum garnets such as YAG:Ce, doped lutetium aluminum garnets such as LuAG:Ce, doped silicon nitride materials such as Eu-doped CaAlSiN3, or the like. Doping materials can generally be, for example, Ce, Tb, Eu, Yb, Pr, Tm, and / or Sm. Additional doping, i.e., co-dopants, is also possible. However, other substances and combinations of substances can also be used, depending on the desired properties of the source light.

[0047] Furthermore, a combination of the solid-state light source and the phosphor can be provided, in which the source light is provided by a superposition of the light emitted by the solid-state light source and the light emitted by the phosphor. Providing the source light through the aforementioned superposition has the advantage that the spectral adjustability of the source light can be further improved. For example, it is possible to use a laser light source that provides blue light and applies it to a suitable phosphor, the emitted light of which is superimposed with the blue light of the laser light source. Particularly advantageously, white light with a high luminance can be provided here, for example. Light source designs that enable this are also known under the term LARP.In a LARP, the phosphor can be designed for transmission or reflection. Depending on the technology, it can also be provided that laser light not converted by the phosphor is superimposed with the converted light of the phosphor. For this purpose, an optical superposition loop can be provided, by means of which the superposition can be achieved. Such a superposition loop is also called a blue loop. The blue laser light can be directed via a dichroic mirror onto the phosphor, which, for example, reflects yellow light, which passes through the dichroic mirror by transmission. By using this dichroic mirror, blue light is additionally superimposed on the yellow light in order to provide white light. This allows the light source to be influenced in many different ways with regard to the source light.As will be explained below, this results in a number of particularly advantageous possibilities that allow the light emission surface and / or the radiation behavior of the light source to be adjusted over a wide adjustment range.

[0048] In addition to changing the luminance by adjusting a pump beam effect on a surface of the phosphor, it may also be advantageous for certain applications to alternatively or additionally influence beam parameters at the light source output. This will be discussed further below.

[0049] According to the invention, the light source has an adjustable source optics unit for adjusting the light emission area and / or the radiation behavior. In order to adjust the light emission area in a LARP, for example, it can be provided that a focus of the laser light on the phosphor is selected in a suitable manner with regard to its dimensions. The area of ​​the phosphor exposed to the laser light emits light essentially in the manner of a Lambertian radiator. The light emission area can thus be adjusted by the dimensions of the focus. The source optics unit can serve this purpose. With the source optics unit, the desired focusing can be achieved by influencing the laser light before it is applied to the phosphor.In addition, the source optics unit can also include, for example, a zoom optic, which can be used to adjust a suitable operating point for coupling the light from the light source into a light guide as the optical unit. Preferably, a core diameter and a numerical aperture are taken into account.

[0050] The source optical unit preferably has movable optical elements by means of which the size of the light source can be influenced. Preferably, at least one of the optical elements or at least some of the optical elements can be adjusted by means of a respective drive unit, which is preferably an electric drive unit. The adjustment is preferably carried out as a function of or by means of the source control signal. In particular, in light sources of the LARP type, such optical elements are already present. The invention uses the already present optical elements with regard to a suitable adjustment option. Combined with the information about how the optical unit is currently adjusted, the light emission area or the radiation behavior can thus be achieved in a predeterminable manner by adjusting the source optical unit.

[0051] The source optics unit is preferably controllable by means of the source control signal. The source optics unit can comprise one or more lenses, one or more prisms, one or more mirrors, combinations thereof, and / or the like as movable or adjustable optical elements. For example, the movable optical elements can be designed to be adjustable with regard to their positioning. The adjustability can be implemented manually. However, it is preferably implemented at least partially automatically, for which purpose the source control signal can be used. The source control signal can thus be used not only to adjust light-emitting elements such as light-emitting diodes, laser diodes, and / or the like, but can also be used to adjust the movable optical elements of the source optics unit.

[0052] In light-emitting diode arrays, particularly in matrix-type light-emitting diode arrays with high packing density, the possibility of cooling the power loss of the light-emitting diode array often limits the maximum current density of the light-emitting diode array. If a particularly high luminance or a high luminous flux density is desired, particularly in a central region of the light-emitting diode array, overall heat dissipation can be improved by partially switching off light-emitting elements or light-emitting diodes of the light-emitting diode array that are, for example, located at a greater distance around a center. This allows the remaining light-emitting elements or light-emitting diodes of the light-emitting diode array to be operated at higher current densities, thus achieving a correspondingly higher light emission. A similar approach can also be provided for a laser-based light source.

[0053] According to the invention, the source optical unit comprises at least one lens arranged to be movable along an optical axis of the emitted source light, at least one adjustable mirror element, and / or at least one adjustable aperture unit. These aforementioned elements make it easy to adjust the light emission surface and / or the radiation behavior of the light source as a whole. This embodiment proves particularly advantageous in conjunction with a solid-state light source of the type of a LARP, in which such optical elements are already present. These only need to be suitably designed to be movable so that the desired functionality can be achieved within the scope of the invention. For example, it can be provided that the lens can be moved along the optical axis of the source light.It is also possible to achieve a corresponding adjustment option using an adjustable mirror element, for example, a micromirror array comprising a plurality of individually adjustable mirror elements, in particular a micromirror, e.g., a DMD, LCoS (Liquid Crystal on Silicon), or LCD (Liquid Crystal Device). Furthermore, an adjustable aperture unit can of course also be provided, which can be used to adjust the source light. For this purpose, the aperture unit can have different aperture sizes or even an adjustable aperture.

[0054] According to the invention, the source optics unit has an adjustable light scattering unit. The light scattering unit allows the radiation behavior of the light source to be influenced in a particularly simple manner. The light scattering unit can be formed, for example, by a diffusion disc that provides different scattering properties depending on the setting.

[0055] The light source preferably comprises a phosphor and is designed to excite the phosphor, depending on the source control signal, at least partially, preferably on average over time, to emit the source light. For example, it is possible to provide excitation light by means of one or more light elements of the light source, which is directed onto desired surface areas of the phosphor in order to excite the phosphor in a predeterminable manner to emit the source light. For example, it is possible to expose the phosphor to the excitation light line by line or point by point. This naturally allows the phosphor to be exposed to the excitation light in any desired pattern, so that it can be excited to emit any desired light. This makes it possible to adjust not only the light emission area, but also the radiation behavior with respect to the source light.The excitation light can be provided by light emitted from the solid-state light source.

[0056] Particularly advantageously, the lighting device comprises a control unit for providing the source control signal. The control unit is preferably designed to specify or detect a setting of the optical unit and is further designed to determine the source control signal depending on the specified or detected setting of the optical unit. As a result, information about the setting of the optical unit of the lighting device is available on the light source side, so that a correspondingly adjusted setting of the light source can be made. Preferably, the control unit can also adjust the light entrance pupil and / or the acceptance angle of the optical unit.For this purpose, the control unit can, for example, interact with a camera or a LiDAR system, which can be attached to an effect light, for example, so that the position of an object to be illuminated can be detected and / or the movement trajectory of an object such as an actor, a singer, or the like can be tracked or predicted. The control unit can also receive control commands from an external control device via WLAN, RADIO, and / or the like. However, it can also simply be provided that the light entrance pupil and / or the acceptance angle of the optical unit is detected by means of one or more suitable sensors and made available for the provision of the source control signal. The control unit preferably also uses the source control signal to adjust the optical unit. In this case, therefore, only a single control signal is required for both units of the lighting device.The control unit can be an electronic circuit that can include a program-controlled computer unit. The desired functionality of the computer unit can be provided by means of a suitable computer program. Of course, a hardware circuit can also be provided, at least in part.

[0057] According to a further development, it is proposed that the light emission surface and / or the radiation behavior be adjusted for a predetermined spectral range of the source light. This configuration makes it possible to implement spectrum-selective functionalities, preferably with regard to the light emission surface and the radiation behavior. This makes it possible to take into account a spectral dependence of the light entrance pupil and / or the acceptance angle of the optical unit. Overall, the flexibility of the invention can be further improved. This allows, for example, in the case of a white light spot with a colored light halo, for example a red light halo, a corresponding adjustment of the light source size so that the light source is adapted with regard to the colored or red light on the one hand and also to the light spot on the other, for example with regard to white light or the like.Of course, a variety of other corresponding applications are also conceivable.

[0058] The effects and advantages stated for the lighting device according to the invention apply equally to the method according to the invention, and vice versa. Consequently, device features can also be formulated as method features, and vice versa.

[0059] Further advantages and features can be found in the following description of exemplary embodiments with reference to the accompanying figures. In the figures, identical reference numerals denote identical features and functions.

[0060] They show: Fig. 1 shows a schematic representation of a first embodiment of a lighting device with a light source, the light emission source and the radiation behavior of which can be adjusted with respect to the source light emitted by the light source according to the invention; Fig. 2 a schematic representation of a second embodiment of a lighting device according to the invention; Fig. 3 is a schematic representation of a third embodiment of a lighting device according to the invention; and Fig. 4 a schematic representation of a fourth embodiment of a lighting device according to the invention.

[0061] Fig. Figure 1 shows a schematic representation of a first embodiment of a lighting device 10 for emitting light according to the invention. The lighting device 10 comprises a light source 12 for emitting source light 20 and an adjustable optical unit 22 configured to provide the light to be emitted by the lighting device 10 using the source light 20.

[0062] In this case, the optical unit 22, in addition to further optical elements not shown, has an integrator rod 50 as a light guide into which the source light 20 is to be coupled. In this regard, the light guide 50 provides a correspondingly predetermined light entrance pupil 24 and an acceptance angle (not shown in detail). These variables serve in a known manner to indicate the conditions under which the source light 20 can be received by the optical unit 22. In a manner not further specified, the source light 20 received by the optical unit 22 is further processed so that the light to be emitted by the lighting device 10 can be provided. In other embodiments of the invention, one or more further optical elements can be provided instead of the integrator rod 50 or in addition to it, for example gobos, reflectors, specially shaped lenses, fiber optics or the like.

[0063] The source light 20 is provided in this case by the light source 12, which is designed in the manner of a LARP light generation source. For this purpose, the light source 12 in this case comprises a matrix of laser diodes 28 as solid-state light sources, of which only eight laser diodes 28 can be seen in the side view shown, and to which respective lenses 52 are assigned. The laser diodes 28 emit laser light 60 in the present case in a blue spectral range. Via a mirror matrix 54 in the manner of a mirror staircase, the laser light 60 emitted by the laser diodes 28 is fed to a laser optics unit 32, which includes, among other things, a plano-convex lens 58 and a biconcave lens 40. By means of a mirror 62, the laser light 60 is fed to a phosphor disk 30 via a source optics unit 34. The phosphor disk 30 is driven in the usual way to rotate about an axis A.

[0064] The source optics unit 34 here comprises a first lens 66 and a second lens 68 that optically interacts with the first lens 66 and is designed as a plano-convex lens. Using the source optics unit 34, the laser light 60 can be focused on the phosphor disk 30 in the desired manner in order to expose the phosphor of the phosphor disk 30 to the laser light 60 as excitation light in a predeterminable manner, so that the phosphor emits the source light 20. By focusing the excitation light on the phosphor disk 30, the light emission surface 26 and the radiation behavior can be determined.

[0065] The source light 20 emitted by the phosphor disk 30 due to the exposure to the excitation light, in this case consisting of a portion of wavelength-converted laser light and a portion of non-wavelength-converted laser light, passes through a lens 76 and is then deflected again by means of a further mirror 62 in order to pass through a further source optical unit 70, which then provides the source light 20 for the optical unit 22.

[0066] The source optics unit 70 comprises in the present case a biconvex lens 42, a filter disk 72 and a further lens 74, so that a good adaptation to the light entrance pupil 24 and the acceptance angle of the optics unit 22 can be achieved.

[0067] The structure described up to this point essentially corresponds to a light source in the style of a LARP system. In contrast to the conventional LARP system, the invention additionally provides that the biconcave lens 40 of the laser optics unit 32 can be moved along an optical axis of the laser light 60. Alternatively or in addition to the moveability of the biconcave lens 40, a moveability of the plano-convex lens 68 of the source optics unit 34 is also provided. By appropriately moving at least one of these lenses, the focusing of the laser light 60 on the phosphor disk 30 can be influenced. For example, a diameter of the focus on the phosphor disk 30 can be influenced. This adjustment option achieves the inventive adjustment option of the light emission surface 26, which is provided by the phosphor disk 30.This allows the source light 20 emitted by the phosphor disk 30 to be varied with regard to the light emission surface 26 and the radiation behavior.

[0068] A control unit 82 of the lighting device 10 can transmit a current setting of the optical unit 22, so that data regarding the light entrance pupil 24 and the acceptance angle of a light entrance opening (not further designated) of the optical unit 22 are available. Based on this data, the control unit 82 determines a source control signal for controlling the light source 12, by means of which the lenses 40, 68 can be moved individually or jointly in a suitable manner so that the required light emission area 26 and the radiation behavior for the source light 20 can be provided in a suitable manner in order to achieve the best possible coupling of the optical unit 22 to the light source 12. With the source control signal, the lens 40 and / or the lens 68 can be moved automatically into suitable positions in order to achieve the desired light emission of the source light 20.Even if an automated adjustment of the light source 12 is provided in the present case, it is of course also possible to make the desired settings at least partially manually.

[0069] Even if a movement of the lenses 40, 68 is provided in the present case, it can of course also be provided that a corresponding adjustment of the focus of the laser light 60 on the phosphor disk 30 can be achieved by moving other of the aforementioned elements of the LARP system, for example by moving the first mirror 62, the lens 66 and / or the like.

[0070] To adjust the focus on the phosphor disk 30, a diffusion disk 48 can also be used, which in this embodiment is arranged between the first mirror 62 and the biconvex lens 40. The diffusion disk 48 can serve to modify the laser light 60 in a suitable manner. For this purpose, the diffusion disk 48 can also be designed to be interchangeable, so that different diffusion characteristics can be provided.

[0071] Thus, the invention also allows, among other things, the etendue of the light source 12 to be controlled or adjusted as desired. As is known, the etendue of the light source 12 cannot be substantially changed using other conventional optical elements. This distinguishes the invention from the prior art because, unlike the prior art, the invention allows for a variation of the etendue or its adjustment.

[0072] The previously described light source 12 based on the LARP principle uses a fluorescent disk 30 designed for transmission. In principle, the fluorescent disk 30 can also be designed for reflective operation, which naturally results in corresponding adaptations to the design and light guidance of the LARP. However, these do not need to be discussed further here, especially since they are not relevant to the basic concept of the invention, namely the adjustability of the light-emitting surface 26 and the radiation behavior.

[0073] Furthermore, it can of course also be provided that the phosphor of the phosphor disk 30 uses the laser light 60 completely or at least only partially to provide the source light 20. In the case of partial use, for example, a superposition of light emitted by the phosphor due to the excitation by the laser light 60 with a remaining portion of the laser light 60 can be achieved in order to form the source light 20.

[0074] Fundamentally, various options are conceivable as to how a source control signal can be routed to the light source 12 and in particular to the adjustable optical elements in order to be able to set an optimal light source size of the light source 12 at a given time. For example, it is possible for the lighting device 10 to receive a control signal, for example in the form of a DMX signal or the like. The control unit 82 of the lighting device 10 evaluates this signal and generates suitable control signals for the adjustable elements such as the lenses 40, 68. In the simplest case, this can be done using a table in the form of a look-up table, in which an associated control signal for the respective corresponding adjustable element is stored for all relevant DMX signals.Furthermore, it is also possible for the light source 12 and the optical unit 22 to each receive their own DMX signal in order to make the respective settings. Furthermore, it is possible for the lighting device 10 to receive a DMX signal, which serves to adjust the optical unit 22, and for a sensor unit of the lighting device 10 to determine a setting of the optical unit 22 and provide a suitable source control signal to the light source 12.

[0075] The optics unit 22 may, for example, include an adjustment of a gobo wheel, a zoom optic and / or the like.

[0076] The invention thus allows an optimal adaptation of the light source 12 to the requirements needed at a particular time depending on a respective setting of the optical unit 22, for example a luminance or the like, and can thus in particular reduce efficiency losses and, above all, also a thermal load on the light source 12 and the lighting device 10 as a whole.

[0077] Fig. Figure 2 shows a further embodiment of a lighting device 10 according to the invention, which is basically based on the embodiment as shown in Fig. 1 has already been explained, which is why reference is made to the relevant explanations.

[0078] The lighting device 10 according to Fig. 2 differs from the lighting device 10 according to Fig. 1 by the light source, which in this case is formed by a light source 14. The light source 14 basically has the same elements as those already explained with reference to the light source 12, which is why in this regard, reference is also made to the explanations regarding Fig. 1 is referred to.

[0079] In contrast to Fig. 1, the diffusion plate 48 is designed as a wheel having a plurality of different scatterers. The individual scatterers of the diffusion plate 48 differ essentially in their respective individual scattering angles, whereby a spot size of the focus of the laser light 60 on the phosphor plate 30 can be adjusted. The advantage here is that the propagation is still collinear, and an angular error with respect to the laser light 60 can be largely avoided. The adjustment of the diffusion plate 48 is carried out by means of the control unit 82.

[0080] In this embodiment, it is also provided that the biconvex lens 42 of the source optics unit 34 is movable along the optical axis of the source light 20. This allows for further adjustment. Overall, however, the light emission surface 26 continues to be provided by the phosphor disk 30, depending on the focus of the laser light 60 on the phosphor disk 30.

[0081] The biconvex lens 42 provides a zoom optic at the output of the light source 14. This allows a zoom effect of the angles to be achieved and an image in a focal plane to be adjusted interdependently. In this way, a suitable operating point for coupling the source light 20 into the light guide 50 of the optical unit 22 can be achieved. This can be particularly advantageous when the position of the light entrance pupil changes, as can be the case, for example, with multiple gobo planes in moving head effect lighting applications.

[0082] Fig. 3 now shows a light source 16, which is basically based on the construction of the light sources 12 and 14, as shown in the Fig. 1 and Fig. 2 described so far. In contrast to the previously described designs, it is provided here that the phosphor disk 30 with the phosphor is operated in reflective mode, with at least a portion of the laser light 60 impinging on the phosphor disk 30 passing through transmitted light recesses introduced into the phosphor disk 30. Regarding the laser or source optics units 32, 34, and 36, reference is made to the preceding explanations. The adjustment is carried out in each case by means of the control unit 82.

[0083] The difference compared to the previously described embodiments of the light sources 12, 14 is that the laser light 60 passing through the phosphor disk 30 is deflected via mirrors 62 in the manner of a blue loop and superimposed on the light emitted by the phosphor of the phosphor disk 30 to provide the source light 20. For this purpose, a dichroic mirror 64 is provided, which is reflective to the laser light 60 but transmissive to the conversion light emitted by the phosphor disk 30.

[0084] The laser light 60 passing through the phosphor disk 30 is first guided via a lens 76 to a first mirror 62, then via the source optics unit 34 with the biconvex lens 42 to a second mirror 62, which guides the source light to the diffusion disk 48, from where it is guided via a further mirror 62 to the dichroic mirror 64 on the opposite side, so that the reflected laser light 60 is superimposed on the light emitted by the phosphor disk 30 to form the source light 20. The other elements correspond to those already described with reference to the preceding embodiments, which is why reference is made to the corresponding explanations in this regard. The phosphor disk 30 is designed as a reflective phosphor wheel, which is at least partially transparent to the blue laser light, in particular due to transmitted light cutouts introduced therein.In this case, a transmitting area, for example a slot or a hole, is provided in the phosphor wheel.

[0085] A further development of the examples described above results from the fact that, with reference to the exemplary embodiments described above, the light source 16 is provided with a mirror matrix 56 which has movable individual mirrors 80. The mirror matrix 56 thus provides an active adjustment element which can be controlled or adjusted, for example, by means of a piezoelectric actuator. This can achieve, for example, that with suitable control, a high-frequency oscillation is carried out which, on average over time, leads to an enlarged area in the plane of the phosphor disk 30 with the laser light 60 applied. There is thus a relationship between the amplitude of the control of the actuators and the focus on the phosphor disk 30. However, an influence on beam propagation in the region of the blue channel must be taken into account.

[0086] Fig. 4 shows a further embodiment of a lighting device 10, which is basically based on the embodiment according to Fig. 3, which is why reference is made to the relevant explanations. In contrast to the design according to Fig. 3, the lighting device 10 comprises a light source 18 which is essentially the same as the light source 16 according to Fig.3. In contrast to the light source 16, the light source 18 additionally has a further source optics unit 38, which has an adjustable micromirror 46, which can be driven by a piezoelectric actuator. Alternatively, a plurality of micromirrors can be provided, for example a DMD or the like. By means of the micromirror 46, the focus or the focus position on the phosphor disk 30 can be adjusted in order to achieve the effects according to the invention. For this purpose, as described above in connection with the individual mirrors 80, the amplitude of the actuator can be adjusted accordingly, which is controlled by the control unit 82. Otherwise, the light guidance corresponds to that already explained with reference to the light source 16.

[0087] The invention thus makes it possible overall to adjust the light emission surface 26 as well as the radiation behavior of the light source 12, 14, 16, 18 in a suitable manner. They are preferably adjusted depending on a light entrance pupil 24 and an acceptance angle of the optical unit 22 in order to achieve the best possible coupling of the source light 20 into the optical unit 22. The invention thus also allows the etendue of the light source 12, 14, 16, 18 to be adjusted as needed.

[0088] The embodiments serve only to explain the invention and are not intended to limit it. LIST OF REFERENCE SYMBOLS 10 Lighting device 12 Light source 14 Light source 16 Light source 18 Light source 20 source light 22 Optical unit 24 Light entrance pupil 26 light emission surface 28 laser diodes 30 fluorescent disc 32 Laser optics unit 34 Source optics unit 36 Source optics unit 38 Source optics unit 40 lens 42 lens 46 micromirrors 48 Diffuser 50 light guides 52 lenses 54 Mirror matrix 56 Mirror matrix 58 lens 60 laser light 62 mirrors 64 dichroic mirrors 66 lens 68 lens 70 Source optics unit 72 filter disc 74 lens 76 lens 80 individual mirrors 82 Control unit

Claims

[1] Lighting device (10) for emitting light, comprising: - a light source (12, 14, 16, 18) for emitting source light (20), and - an adjustable optical unit (22) which is designed to provide the light to be emitted by the lighting device (10) using the source light (20), wherein the light source (12, 14, 16, 18) is designed to adjust a geometric extent of a light emission surface (26) of the light source (12, 14, 16, 18) emitting the source light (20) and / or a radiation behavior and / or a spectral property of the light source (12, 14, 16, 18) with respect to the source light (20) depending on a light entrance pupil (24) and / or an acceptance angle of the optical unit (22) for the source light (20), characterized bythat the light source (12, 14, 16, 18) is designed to adjust the light emission surface (26) and / or the radiation behavior and / or the spectral property depending on a source control signal and is further designed to adjust a luminous flux of the source light (20) independently of the light emission surface (26) and / or the radiation behavior, that the light source (12, 14, 16, 18) has an adjustable source optics unit (32, 34, 36, 38) for adjusting the light emission surface (26) and / or the radiation behavior, that the source optics unit (32, 34, 36, 38) has at least one lens (40, 42, 44) arranged to be movable along an optical axis of the emitted source light (20), at least one adjustable mirror element (46, 54, 56) and / or at least one adjustable diaphragm unit, and the source optics unit (32, 34, 36, 38) further has an adjustable light scattering unit (48). [2] Lighting device according to claim 1, characterized by that the light source (12, 14, 16, 18) comprises a solid-state light source (28), in particular a combination of the solid-state light source (28) with a phosphor (30) which is exposed to light emitted by the solid-state light source (28), particularly preferably a combination of the solid-state light source (28) with the phosphor (30), in which the source light (20) is provided by a superposition of the light emitted by the solid-state light source (28) and the light emitted by the phosphor (30). [3] Lighting device according to one of the preceding claims, characterized by that the light source (12, 14, 16, 18) has a phosphor (30) and is designed to excite the phosphor (30) at least partially, preferably on average over time, to emit the source light (20) as a function of the source control signal. [4] Lighting device according to one of the preceding claims, characterized by a control unit (82) for providing the source control signal. [5] Lighting device according to claim 4, characterized by that the control unit (82) is designed to predetermine or detect a setting of the optical unit (22) and is designed to determine the source control signal depending on the predetermine or detected setting of the optical unit (22). [6] Method for operating a lighting device (10) which emits light, comprising: - emitting source light (20) by means of a light source (12, 14, 16, 18), and - providing the light to be emitted by the lighting device (10) by means of an adjustable optical unit (22) which uses the source light (20), wherein a geometric extension of a light emission surface (26) of the light source (12, 14, 16, 18) emitting the source light (20) and / or a radiation behavior and / or a spectral property of the light source (12, 14, 16, 18) with respect to the source light (20) is adjusted depending on a light entrance pupil (24) and / or an acceptance angle of the optical unit (22) for the source light (20), characterized by that the light source (12, 14, 16, 18) adjusts the light emission surface (26) and / or the radiation behavior of the light source (12, 14, 16, 18) and / or the spectral property with respect to the source light (20) depending on a source control signal and / or adjusts a luminous flux of the source light (20) independently of the light emission surface (26) and / or the radiation behavior, wherein the light source (12, 14, 16, 18) has an adjustable source optics unit (32, 34, 36, 38) for adjusting the light emission surface (26) and / or the radiation behavior, the source optics unit (32, 34, 36, 38) has at least one lens (40, 42, 44) arranged to be movable along an optical axis of the emitted source light (20), at least one adjustable mirror element (46, 54, 56) and / or at least one adjustable aperture unit, and the source optics unit (32, 34, 36, 38) further has an adjustable light scattering unit (48). [7] Method according to claim 6, characterized by that the light emission surface (26) and / or the radiation behavior is adjusted for a predetermined spectral range of the source light (20). [8] Method according to one of claims 6 or 7, characterized bythat a setting of the optical unit (22) is detected and the source control signal is determined depending on the detected setting of the optical unit (22).

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