Device and method for irradiating at least a part of a human or animal body with electromagnetic radiation

Abstract

The present invention relates to devices and methods for irradiating at least a part of a human or animal body, and to a device for operating light-emitting diodes for the aforementioned purpose. The device comprises a plurality of first luminous means (102, 102.1, …, 102.4) designed as LEDs and arranged on a carrier (101), and a temperature sensor (103) arranged at a defined point (150) on the carrier (101) and serving to measure an actual temperature at the defined point. A cooling system (108) is designed for direct and / or indirect heat dissipation from the carrier (101), and a closed-loop control unit (106) is designed for closed-loop control of an operating temperature of the plurality of first luminous means (102, 102.1, …, 102.4) designed as LEDs, on the basis of the measurement of the actual temperature at the defined point (150).

Description

[0001] Device and method for irradiating at least part of a human or animal body with electromagnetic radiation

[0002] The present invention relates to a device for irradiating at least one part of a human or animal body, as well as a device for operating light-emitting diodes for said purpose.

[0003] The present invention further relates to a device for operating light-emitting diodes, in particular UV light-emitting diodes, for use in devices designed to expose at least a part of a human or animal body to electromagnetic radiation, in particular electromagnetic radiation in the wavelength range of less than 380 nm.

[0004] Furthermore, the present invention relates to corresponding methods for operating the devices according to the invention, as well as to a solarium comprising the device according to the invention, all according to the preambles of the independent patent claims.

[0005] Technological background

[0006] When operating devices for irradiating at least part of a human or animal body with electromagnetic radiation, safety regulations must be observed, and it must be ensured that the irradiation is carried out within operationally safe parameters and in a controlled manner. In the past, devices for irradiating a human or animal body, such as tanning beds, were operated with fluorescent tubes. With the advancement of LED technology and in order to reduce the comparatively higher energy and wear costs of fluorescent tubes, irradiation devices are increasingly being converted entirely to LEDs.

[0007] LEDs are diodes that emit light when an electric current is passed through them in a defined direction. The wavelengths achieved with LEDs depend on the properties of the diode and the choice of semiconductor. LEDs capable of emitting light in the ultraviolet spectrum, for example, are equipped with gallium compounds such as gallium nitride. The current flow causes the LED to heat up during operation. This heating can lead to a shift in the spectral composition of the emitted electromagnetic wavelengths, a process known as wavelength drift.

[0008] However, when used on the human or animal body, compliance with the specified wavelength ranges is particularly important. When using UV LEDs for skin irradiation, two fundamental technical parameters must be considered: the radiant power and the spectral wavelength.

[0009] For example, with UV-B LEDs, even small shifts in wavelength can lead to undesired erythema. Irradiation devices are generally designed to deliver a defined intensity of radiation within a defined spectral range to achieve the desired irradiation effect. For the safe use of such irradiation devices, it is essential that, even when the LEDs are fully undimmed, i.e. operating at maximum power, certain spectral bandwidths are not exceeded or undershot. Various standards and regulations limit the power output to a permissible maximum. This limit must be observed at all times. If PWM control is used to dim the LEDs, the maximum value (100% control) must not exceed the required limit.

[0010] The spectral wavelength influences the effect of the radiation and is significant for erythema. Shorter-wave spectral components are more critical for erythema. The UVB range is considered particularly critical because the evaluation curve is very steep here, and a shift in the spectrum of just 2 nanometers can roughly double the rated output.

[0011] Controlling a potential thermal drift in the wavelength spectrum of an LED, regardless of the specific spectrum, also allows for much more precise parameterization of the irradiation, thus making it more energy-efficient. Thus, controlling the thermal drift of an LED not only has safety-related advantages but also contributes to the efficient operation of devices used to irradiate a human or animal body. This is particularly important in tanning beds.

[0012] Solariums are used to irradiate the human body with UV radiation, i.e. light in the electromagnetic wavelength range of less than 380 nm, in order to achieve a cosmetic effect, namely the tanning of the skin.

[0013] UV-A LEDs are primarily responsible for the tanning effect. UV-B LEDs can be used as a supplement, for example, to achieve positive effects on vitamin D synthesis. However, UV-B radiation has shorter wavelengths than UV-A, which is particularly prone to causing erythemal damage.

[0014] Therefore, there is a need, especially in the tanning industry, for safe and efficient ways to control erythemal safety and efficient management of LEDs in the relevant actinic radiation ranges.

[0015] Description of the invention

[0016] It is therefore an object of the present invention to provide a device and / or a method of the type mentioned above that enables efficient monitoring of erythemal safety. Furthermore, an object of the present invention is to eliminate at least one disadvantage of the known method.

[0017] A particular object of the present invention is to provide a device and / or method which enables reliable compliance with specifications regarding the irradiation of animal or human bodies, for example regulatory specifications.

[0018] At least one of the above-mentioned objects has been achieved by a device and / or a method according to the characterizing part of the independent claims.

[0019] One aspect of the present invention relates to a device for irradiating at least part of a human or animal body with electromagnetic radiation, in particular with actinic radiation. For the purposes of the present invention, actinic radiation can be understood as a specific electromagnetic radiation with a physiological effect. In the broadest sense, actinic radiation within the meaning of the present application can be understood as radiation with a wavelength of approximately 200 nm to approximately 1500 nm. For the purposes of the present invention, lower-wavelength radiation and radiation in the X-ray or gamma radiation range are explicitly excluded.

[0020] The device according to the invention comprises a plurality of first lighting means designed as LEDs arranged on a carrier.

[0021] It further comprises a temperature sensor which is arranged at a defined point on the carrier and is designed to measure an actual temperature at said defined point.

[0022] The device according to the invention further comprises a cooling system for direct and / or indirect heat dissipation from the carrier.

[0023] Furthermore, the device according to the invention comprises a control unit for controlling an operating temperature of the plurality of first lighting means designed as LEDs as a function of the measurement of the actual temperature at the defined point.

[0024] It has surprisingly been found that the device according to the invention enables efficient and safe operation of a device for irradiating at least one part of a human or animal body.

[0025] In a particular embodiment, the first light source designed as an LED is configured to emit light in a first wavelength range.

[0026] In the context of the present invention, light can be understood as electromagnetic radiation in a wavelength range from approximately 200 nm to 1500 nm, which thus also includes light in spectra that cannot be perceived by the human eye, such as UV-A, UV-B, UV-C and / or infrared light. In the context of the present invention, the first illuminant designed as an LED can emit the radiation directly or via a photoluminescent additional substance that can be provided in the vicinity of the first illuminant designed as an LED. In the context of the present invention, the carrier can be understood as an LED circuit board that is suitable for accommodating the plurality of first illuminants designed as LEDs. In the simplest embodiment, for example, the LED circuit board can be designed as a substantially flat circuit board that has the LEDs on one side of the flat plane.However, in special embodiments, the carrier may also have other geometries that deviate from a flat board, depending on the needs of the person skilled in the art responsible for implementing the teachings of the invention.

[0027] In the context of the present invention, a defined point is, for example, a point determined in advance. Such a defined point can be determined, for example, by means of an experimental measurement method.

[0028] In a particularly preferred embodiment, the experimental measurement method is customized for a specific support. This means, for example, that the defined point on one support may be different than on another, apparently structurally identical support. Alternatively and / or additionally, the defined point can be determined for a specific support type and then implemented identically in all supports that have the same or at least comparable geometry and the same or at least comparable arrangement of the plurality of first light sources embodied as LEDs.

[0029] In the context of the present invention, measuring an actual temperature can be understood, for example, as the measurement of a temperature at a defined point at a specific time. For example, the actual temperature can be understood as the current temperature at the time of measurement.

[0030] In the context of the present invention, direct heat dissipation can be understood as meaning that the heat is transferred directly to a dissipating medium.

[0031] For the purposes of the present invention, indirect heat dissipation can be understood as an intermediate fluid absorbing the heat, and the removal of the intermediate fluid transports the heat away from its source. Air, for example, is particularly suitable as an intermediate fluid in the present invention.

[0032] In an alternative or supplementary embodiment, a coolant can be provided as an intermediate fluid. The coolant can, in particular, be designed to form a thermal bridge between a heat dissipation element and the carrier. For this purpose, the coolant can be guided, for example, in heat pipes that extend from the carrier to a heat dissipation element, for example, a fan. In a particular embodiment, the coolant is actively guided in the heat pipes, for example, via a pumping element. In an alternative embodiment, the coolant is passively guided via convection.

[0033] In a particular embodiment, the defined point on the carrier is an experimentally determined point on the carrier. The point can be determined experimentally, for example, by placing a plurality of sensors on the carrier.

[0034] Alternatively and / or additionally, the carrier can be analyzed, for example, using an infrared camera, and a point can be determined experimentally based on optically detected temperature gradients. Particularly preferably, the point is determined in an operating state of the plurality of first light sources embodied as LEDs, which consume the full power of the LEDs. For example, the experimentally determined point can ensure that a specific operating state, for example, a specific operating temperature, prevails there during operation, which can be considered the maximum operating temperature of the designated carrier.

[0035] In a particular embodiment, the defined point on the carrier is located in a range of the highest measured isotherms. Using the highest measured temperature range for the placement of the temperature sensor ensures that none of the plurality of LEDs heats up above a certain threshold without this being detected by the temperature sensor.

[0036] The carrier can, for example, be analyzed based on a temperature profile and divided into isothermal regions. Isothermal regions essentially have the same temperature within a certain tolerance value. The tolerance value particularly preferably lies between a maximum of one and five percent deviation from a measured temperature value. The isotherms can reveal corresponding zones that heat up more rapidly during operation than other zones. These zones are used to establish the defined point. By establishing the defined point in a region of the isotherms with the highest temperature during operation of the majority of LED-embodied light sources, it can be ensured that a maximum temperature of the irradiation device can always be monitored by the sensor.This allows cooling effects to be applied in a targeted manner depending on this temperature maximum in order to keep the operation of the plurality of first light sources designed as LEDs within a certain range, in particular so that no defined maximum value is exceeded. For example, the control unit can be designed to regulate the operating temperature of the plurality of first light sources designed as LEDs in operative connection with the cooling system as a function of the actual temperature at the defined point. It goes without saying that there can be a plurality of regions with the highest measured isotherms relative to other regions, for example by there being two or more regions which have the same temperature, but this temperature is higher than in all other measured regions. In this case, for example, the defined point can be defined in one of these regions.

[0037] In a particular embodiment, the device according to the invention comprises a plurality of second light sources configured as LEDs. The plurality of second light sources configured as LEDs can, for example, be designed to emit light in a second wavelength range. This second wavelength range can differ from the first wavelength range. However, the second wavelength range can at least partially overlap the first wavelength range. Alternatively and / or additionally, the second wavelength range does not overlap with the first wavelength range.

[0038] In a specific embodiment, for example, the first wavelength range can be designed to emit radiation in the UV-A range. The second wavelength range can be designed to emit radiation in the UV-B range, for example.

[0039] In a further particular embodiment, the device according to the invention comprises more than two types of a plurality of illuminants designed as LEDs, for example a third, fourth, etc.

[0040] In a specific example, a plurality of third light sources embodied as LEDs can be designed to emit radiation in the infrared range. There are no limits to the combination of light sources for the person skilled in the art, who can base their choice on the requirements of the desired type of irradiation. Preferably, both the plurality of first light sources embodied as LEDs and the plurality of second light sources embodied as LEDs (and further third, fourth, etc. light sources) are arranged on the same carrier. For example, the first and second light sources can be arranged in a specific pattern on the carrier. In particular, the first and second LEDs can alternate in a checkerboard pattern.

[0041] For the purposes of the present invention, the determination of a defined point, as described above by way of example, is carried out accordingly on the fully populated carrier. This can mean that a plurality of first illuminants configured as LEDs and second illuminants configured as LEDs are operated simultaneously at full load.

[0042] Thus, the area with the highest measured isotherm would correspond to the area resulting from the operation of all lamps on the carrier.

[0043] In a particular embodiment, the carrier is designed as a substantially flat plate and divides a space into an irradiation zone and a machine zone. Within the meaning of the present invention, the carrier can, for example, be configured to have all the lighting means on one side of a substantially flat plate. During operation, this side would face the human or animal body and expose it to electromagnetic radiation. The side facing away from the radiation side, i.e. the machine side, would then be designed, for example, to connect the LEDs to the electronics, such as the power supply and / or control. The cooling system can also be arranged on the machine side. The cooling system can, for example, have one or more heat exchangers on the machine side, which are suitable for dissipating the waste heat generated by the LEDs.Particularly preferably, the machine zone is filled with a fluid suitable for absorbing the waste heat. The cooling system can, for example, be designed to remove this fluid or supply fresh fluid. For the purposes of the present invention, fresh fluid is, for example, fluid that is still significantly below the operating temperature of the LEDs and is thus capable of absorbing waste heat as efficiently as possible. The fluid is particularly preferably air.

[0044] Alternatively and / or additionally, other cooling systems comprising liquid cooling may be provided. Liquid cooling systems may, for example, provide hoses filled with water or another liquid medium on the machine zone side of the carrier. These hoses heat up through contact with the carrier and thus with a heat-conducting element that absorbs the waste heat from the LEDs, and then dissipate this heat through a flow.

[0045] In a particular embodiment, the plurality of first illuminants designed as LEDs, in particular also the plurality of second illuminants designed as LEDs, are arranged on the carrier in such a way that they are suitable for irradiation with electromagnetic radiation into the irradiation zone.

[0046] In a particular embodiment, the device according to the invention comprises a cooling system comprising a heat dissipation element. The heat dissipation element can be brought into operative connection with a heated region of the carrier by means of at least one heat pipe or a plurality of heat pipes.

[0047] Particularly preferably, the heat dissipation element comprises ventilation.

[0048] In a particular embodiment, the device according to the invention comprises at least one additional sensor, in particular a further temperature sensor, arranged on the carrier. This additional temperature sensor can be used, for example, as a reference sensor to determine a temperature difference between the value measured at the defined point, i.e., the actual temperature, and a reference temperature measured at another defined point on the carrier.

[0049] In a particular embodiment, the temperature sensor is arranged so that it can be placed on the carrier. Particularly preferably, the carrier and temperature sensor are designed in a modular manner, so that the temperature sensor can be placed at various locations on the carrier.

[0050] In a further special embodiment, the temperature sensor is redundant and several temperature sensors are formed on the carrier. This can then be implemented in practice such that only one of the redundant temperature sensors is in operation at any one time, namely the one located at the defined point. In this embodiment, the defined point can be determined experimentally, as described many times at the beginning. In a special additional and / or alternative embodiment, the temperature sensor is an optical sensor which dynamically determines the warmest point of the carrier in the infrared range, e.g. continuously records an isothermal model of the entire plate and determines the warmest point. The actual temperature measured there is used for control in accordance with the teachings of the present invention.

[0051] In a particular embodiment, the device comprises at least one second temperature sensor designed to measure an ambient temperature. The ambient temperature can be used, for example, to determine a temperature delta compared to the actual temperature, which in turn can be used to regulate the performance of a cooling system. Likewise, the ambient temperature can be used to prevent operation of the device, for example, if the ambient temperature is so high that a temperature delta to the actual temperature is too small to sufficiently cool the LEDs, thus making drift impossible to prevent.

[0052] In a particular embodiment, the cooling system comprises a flow fan. The flow fan is particularly preferably designed as a fan that draws in fluid from the surroundings of the wearer and carries it away from the wearer.

[0053] In another special embodiment, heat pipes are provided around the support, which can be used to remove the fluid. It goes without saying that forced ventilation can be effective both by supplying cool air and by removing warm air. Accordingly, when warm air is removed, relatively cooler air would be drawn in.

[0054] In a special embodiment, the temperature sensor is a non-contact thermometer.

[0055] In an alternative embodiment, the temperature sensor is a contact thermometer.

[0056] A further aspect of the present invention relates to a method for operating a device for irradiating a body with electromagnetic radiation, in particular with actinic radiation. The method according to the invention particularly preferably relates to the operation of a device as described above.

[0057] The method comprises the step of measuring an actual temperature at a defined point on a carrier which comprises a plurality of first light sources designed as LEDs.

[0058] The method further comprises the step of comparing the actual temperature with an experimentally determined target temperature, which is indicative of an operating temperature of the warmest operating lamp of the plurality of first lamps designed as LEDs.

[0059] Furthermore, the method according to the invention comprises regulating a working performance of a cooling system for direct and / or indirect heat dissipation from the carrier as a function of the said comparison.

[0060] In other words, for example, detecting an actual temperature that is too high, which is indicative of the operating temperature of an LED in the majority of LED-embodied light sources, can lead to increasing the performance of a cooling system. By increasing the performance, a cooling system can, for example, dissipate heat more quickly.

[0061] In a particular embodiment, the control occurs continuously as a function of a continuously measured actual temperature and a comparison of this continuously measured actual temperature with an experimentally determined target temperature. The target temperature is determined experimentally in such a way that it ensures that no wavelength drift occurs in any one of the plurality of first light sources configured as LEDs.

[0062] A drift in the sense of the present invention occurs when the spectral composition of the radiation emitted by the light source undergoes a shift. A shift can mean, for example, that a peak shifts by between 0.5 and 10 nm, preferably between 0.5 and 5 nm. A peak at 222 nm, for example, would then emit at 224 nm. A tolerable drift can depend, for example, on the type of LED. For example, with IIV-A, IR, and VIS LEDs, a drift of between 0.5 and 20 nm can be tolerable, whereas with UV-B LEDs, a drift of just 0.5 to 1 nm can lead to undesirable erythemal effects. Ideally, however, the drift is in the maximum range of between 0.5 and 5 nm to ensure both erythemal safety and the desired effect of the irradiation in the said wavelength range.

[0063] In another particular embodiment, the control system is designed to maintain a maximum operating temperature of each of the plurality of first light sources configured as LEDs. Particularly preferably, a maximum operating temperature should be maintained in a range of between 50°C and 60°C.

[0064] In a particularly preferred embodiment, a maximum operating temperature of each of the plurality of LEDs of between 30° C and 70° C, in particular of approximately 60° C, further in particular of 55° C, is maintained.

[0065] In a particular embodiment of the method according to the invention, the control of the working performance of the cooling system comprises controlling a rotational speed of a flow fan, in particular a ventilator.

[0066] In a particular embodiment of the method according to the invention, this comprises a step of determining the defined point. The defined point can be determined, for example, by experimentally defining isotherms based on thermal analyses of a carrier used according to the invention. The defined point can then be determined, for example, such that it lies within a range of isotherms that exhibits the highest temperatures. Ideally, this determination takes place during operation of an irradiation device according to the invention. The determination can be performed once, for example, prior to assembly or fabrication of an irradiation device according to the invention. The determination can also be repeated periodically, for example, to check and / or recalibrate an irradiation device according to the invention.

[0067] In a particularly preferred embodiment, the air is used directly to perform other functions in the device according to the invention, e.g., the ventilation of an irradiation room. WO 2020 / 152251 of JK-Holding GmbH shows such a dual heating and cooling system, as can be implemented in the teaching of the invention.

[0068] In a particular embodiment, the method according to the invention further comprises the step of regulating an operating power of one, several or all of the plurality of first illuminants designed as LEDs, in each case as a function of comparing the actual temperature with an experimentally determined target temperature which is indicative of an operating temperature of the warmest illuminant in operation of the plurality of illuminants designed as LEDs.

[0069] This regulation of the LED's output can be achieved, for example, using pulse-width modulation. This allows the light source to be modulated at a frequency that reduces the overall emitted intensity. This can ensure, for example, that erythemal safety is guaranteed at all times in a very hot operating environment. For example, if the cooling capacity provided by the cooling system is insufficient, dimming the LEDs can reliably prevent erythemal damage.

[0070] In a particular embodiment, the method according to the invention further comprises the step of determining an actual temperature of each and / or the warmest of the plurality of first illuminants embodied as LEDs on the basis of the measured actual temperatures at the defined point on the carrier. This determination of the actual temperature of each and / or the warmest of the plurality of first illuminants embodied as LEDs can, for example, be carried out computationally on the basis of experimental data and be a function of determined actual temperatures. The actual temperature is indicative of the operating temperature of each individual LED on a carrier according to the invention, for example, and from this it can be derived what operating temperature the warmest of these illuminants has.

[0071] A further aspect of the present invention relates to a method for operating light-emitting diodes, in particular UV light-emitting diodes, which are suitable for use of the type mentioned at the outset.

[0072] In a particular embodiment, the present invention relates to methods for use in devices designed to expose at least a part of a human or animal body to electromagnetic radiation in the wavelength range of less than 380 nm.

[0073] The process for operating light-emitting diodes includes the following steps:

[0074] - Providing at least one first LED module with a plurality of light-emitting diodes with a first spectral composition;

[0075] - Recording a plurality of performance data of the first LED module and storing the recorded performance data;

[0076] - definition of a thermal operating point, wherein the thermal operating point is selected to be above the highest expected room temperature at which the device is to be operated;

[0077] - Monitoring the current flow through the majority of LEDs and comparing it with the performance data.

[0078] In a particular embodiment, the providing comprises providing a plurality of light-emitting diodes having a first spectral composition with a peak wavelength in a specific bell curve wavelength range, in particular a specific bell curve wavelength range with a full width half maximum (FWHM) of approximately 0.5 nm to 20 nm, in particular of approximately 1 nm to 20 nm.

[0079] In a particular embodiment, the monitoring and comparison comprises switching off the first LED module in case of a predefined deviation.

[0080] In a particular embodiment, the method comprises providing at least one second LED module, in particular a plurality of LED modules as described above.

[0081] In a particular embodiment, the method further comprises the step:

[0082] - Cooling the first module after reaching the thermal operating point. In a particular embodiment, the electromagnetic radiation is designed for cosmetic purposes, in particular with a first spectral composition in the UV-B range, in particular between 280 nm and 320 nm.

[0083] A further aspect of the present invention relates to a device for operating light-emitting diodes, in particular UV light-emitting diodes, for use in devices designed to expose at least a part of a human or animal body to electromagnetic radiation, in particular electromagnetic radiation in the wavelength range of less than 380 nm. The device is preferably designed to carry out the method described above.

[0084] The device according to the invention comprises at least a first LED module with a plurality of light-emitting diodes with a first spectral composition.

[0085] In a particular embodiment, the device comprises at least a first LED module with a plurality of light-emitting diodes with a peak wavelength in a specific bell curve wavelength range, in particular a specific bell curve wavelength range with a half maximum in full width (FWHM) of approximately 0.5 nm to 20 nm, in particular of approximately 0.5 nm to 5 nm.

[0086] The device according to the invention further comprises at least one exposure chamber for receiving at least one part of a human or animal body, wherein the exposure chamber comprises an effective area which can be exposed to electromagnetic radiation by the at least one first LED module.

[0087] The modules used allow calibration, so that the insert is interchangeable and independent of the location in the device.

[0088] In a particular embodiment, the plurality of light-emitting diodes with a first spectral composition has a peak wavelength in a specific UV-B wavelength range, in particular in a range of between 280 nm and 320 nm.

[0089] In a particular embodiment, the device comprises a plurality of light-emitting diodes with a second spectral composition. This second spectral composition can, for example, emit radiation in the IIV-A range and have wavelengths between 320 and 400 nm.

[0090] In a particular embodiment, the at least one first LED module, in particular each LED module, comprises a control unit for controlling the light-emitting diodes with a first spectral composition on the respective module.

[0091] In a particular embodiment, the at least one first LED module, in particular each LED module, comprises a sensor unit for measuring operating parameters of the light-emitting diodes with a first spectral composition on the respective module, in particular for measuring the temperature of the light-emitting diodes.

[0092] In a particular embodiment, the at least one first LED module, in particular each LED module, comprises a module interface for connection to a device controller, in particular for specifying setpoints from the device controller to the control unit of the module and / or for transmitting operating / error states from the control unit of the module to the device controller.

[0093] In a particular embodiment, a plurality of LED modules are combined to form a module assembly, in particular wherein each module assembly is designed to act upon a part of a human or animal body, wherein the part of a human body is selected from the group consisting of: upper body, in particular torso, in particular arms, in particular shoulders, in particular hands, head, in particular face and lower body, in particular loins, in particular legs, in particular feet.

[0094] In a special embodiment, the LED modules are designed to be interchangeable.

[0095] Two principles can be distinguished when operating LEDs: PWM and constant current. In PWM mode, the diodes are driven by a constant control, which is switched on and off at a high frequency. Dimming is achieved by adjusting the pulse-pause ratio. In effect, the irradiation is always carried out with the same power. To vary the application dose, the application duration can be varied. Dimming occurs only in the eye of the observer and is merely a subjective impression created by averaging the perceived light intensity.

[0096] When operating with constant current sources, the current flow through the LED is varied for dimming. Once set, the control remains constant and is not pulsed. This causes a change in the radiant output. In effect, this means that the application duration always remains constant, regardless of the dimming. The output can be varied to vary the dose. The impression of "dimming" is based on a real change in the luminous intensity of the diodes.

[0097] To ensure safe operation of the LEDs, both the spectrum and the power of the emitted radiation can be monitored. This can be done using optical sensors, which can measure the light spectrum with very fine increments. The sensors can be located near or on the user's skin, for example.

[0098] Alternatively and / or additionally, a sensor diode can be installed. This operates with the same operating parameters as the others, but is not used for applying voltage. The sensor diode can be specifically aligned with the sensor technology.

[0099] Based on data from various LEDs, a shift in the spectral wavelength of LEDs is primarily expected due to variations in operating temperature. Higher temperatures, for example, can result in a shift toward the longer wavelength range.

[0100] Particularly preferably, a variation in the emitted radiation power can be achieved by changing the current control. Increasing the current can cause an increase in power. Preferably, a dependence over a large range can be considered linear. Without being bound to this theory, it was surprisingly discovered that this provides a possibility for calibrating the electronics.

[0101] A further aspect of the present invention relates to a solarium. The solarium is designed to expose at least a portion of a human or animal body to electromagnetic radiation. The electromagnetic radiation is particularly preferably located in a wavelength range of less than 380 nm. The solarium comprises at least one first LED module with a plurality of light-emitting diodes with a first spectral composition. The light-emitting diodes have a peak wavelength in a specific bell-curve wavelength range, in particular in a bell-curve wavelength range with a half-maximum in full width of approximately 0.5 nm to 20 nm, in particular from approximately 1 nm to 20 nm.

[0102] The solarium also has at least one exposure chamber for accommodating at least one part of a human or animal body. The exposure chamber comprises an effective area that can be exposed to electromagnetic radiation by at least one first LED module.

[0103] The LED module comprises a plurality of first light sources configured as LEDs, arranged on a carrier. The module further comprises a temperature sensor, which is arranged at a defined point on the carrier and is designed to measure an actual temperature at this defined point.

[0104] The solarium further comprises a cooling system for direct and / or indirect heat dissipation from the wearer. It also includes a control unit for regulating the operating temperature of the plurality of first LED light sources based on the actual temperature measurement at the defined point.

[0105] In a particular embodiment, the solarium according to the invention comprises a device frame designed to accommodate at least the LED module and the cooling system. Furthermore, the device frame comprises an arrangement suitable for defining the exposure chamber. For example, a substantially two-part solarium can define an exposure chamber by defining a lying surface and a cover surface pivotably arranged above the lying surface. The LED modules can be arranged in the lying surface and / or the cover surface, preferably allowing exposure to the entire human body.

[0106] It is self-evident to a person skilled in the art that the previously described embodiments can be implemented in any combination in an inventive configuration, provided they are not mutually exclusive. Likewise, a person skilled in the art will recognize functional requirements from the structural features of the device, which he or she understands as process features, and vice versa, device features from the structural requirements of the process features.

[0107] The invention will now be explained in more detail below using specific exemplary embodiments and figures, without being limited to these. By studying the figures and examples, the person skilled in the art will recognize further advantageous embodiments of the present invention.

[0108] Character description

[0109] Embodiments of the invention are described with reference to the following figures.

[0110] They show schematically:

[0111] Fig. 1a shows schematically an LED module according to the invention;

[0112] Fig. 1b shows a section of the LED module with a special cooling system;

[0113] Fig. 2a shows isotherms on a support as used in the inventive

[0114] teaching can be used;

[0115] Fig. 2b shows a section of the carrier from Fig. 2a;

[0116] Fig. 2c shows a schematic diagram of the structure of a machine side of an irradiation device according to the invention, or rather an LED module.

[0117] Fig. 3 shows schematically a structure of a control in a device according to the invention, and

[0118] Fig. 4 shows schematically a module according to the invention in its functional mode of operation.

[0119] Implementation of the invention Fig. 1a shows an exemplary and schematic illustration of an LED module according to the invention

[0120] 100, such as can be installed in a solarium, for example. A plurality of first illuminating means 102.1, 102.2, 102.3, 102.4, designed as LEDs, are arranged on a support 101.

[0121] In the present example, the carrier is equipped with all electronic components to enable power supply to the LEDs. Suitable carriers include, for example, glass-fiber-reinforced epoxy plates. Carriers with aluminum cores are also suitable, which are particularly preferred for the inventive solution because they dissipate heat well. Lines 104 extend through the carrier 101 and are operatively connected to a power supply 105. The power supply 105 can be operatively connected to a corresponding control unit (not shown), for example, a control unit capable of controlling the power output of the LEDs 102.1, 102.2, 102.3, 102.4 via pulse-width modulation.

[0122] Also arranged on the carrier 101 is a temperature sensor 103. The temperature sensor 103 is arranged at a defined point on the carrier 101. It serves to measure an actual temperature at the defined point. Suitable temperature sensors are known to those skilled in the art. In the present example, the temperature sensor 103 is connected to a control unit 106. The control unit regulates the operating temperature of the plurality of first illuminating means 102.1, 102.2, 102.3, 102.4 designed as LEDs by regulating the workload of a cooling system 108 that is in control connection with the control unit 106. In its simplest embodiment, the cooling system 108 comprises a fan 109 that serves as a flow ventilation and the rear side of the carrier

[0123] 101, i.e., the machine side of the carrier facing away from the irradiation side, where the first LED-designed light sources 102.1, 102.2, 102.3, 102.4 are arranged, is exposed to cool air. Alternatively, the cooling system 108 can also be configured to dissipate waste heat from the machine side of the carrier 101. This is then achieved by the fan extracting air from this area. Fresh air flowing into this area is comparatively cooler and able to absorb more waste heat from the light sources 102.1, 102.2, 102.3, 102.4.

[0124] This system according to the invention enables continuous monitoring of the current actual temperature at the defined point. From this, the operating temperature of the lamps 102.1, 102.2, 102.3, 102.4 can be derived. In the present example, a fan speed is adjusted accordingly, and a constant operating temperature of the lamps is maintained. Thus, no relevant wavelength drift of the LEDs, especially UV LEDs, occurs. This enables safe and efficient operation of the LED module shown for applications designed for exposure of a human and / or animal body to electromagnetic radiation, especially actinic electromagnetic radiation.

[0125] In this example, UV-A LEDs can be used, for example, to achieve a tanning effect, as is used in solariums.

[0126] Fig. 1b shows a particular embodiment with a cooling system 108, which uses an intermediate fluid for improved heat dissipation from the carrier 101. The cooling system 108 is controlled via an active connection 107. The control can be carried out via a control unit as described above and, for example, based on measured actual temperatures.

[0127] A fan 109 supplies air to a heat exchanger 110. The heat exchanger 110 is traversed by heat segments 111.1, 111.2, into which the heat from the support 101 is conducted via heat pipes 112.1, 112.2.

[0128] Heat pipes 112.1, 112.2, heat segments 111.1, 111.2, and heat chambers 113.1, 113.4 together form heat pipes that can transfer heat via an evaporation and condensation circuit. An intermediate fluid, which has a liquid and a gaseous phase and is guided through heat pipes 112.1, 112.2, heat segments 111.1, 111.2, and heat chambers 113.1, 113.4, is guided via convection from the location of heat generation, i.e., the carrier, to the location of heat dissipation, i.e., the cooling system, in a closed circuit. In this example, heat pipes 112.1, 112.2, heat segments 111.1, 111.2 and heat chambers 113.1, 113.4 are made of copper for better heat conduction with the environment.

[0129] A heat exchanger plate 114 on the support 101 serves to accommodate the heat chambers 113.1, 113.4. This heat exchanger plate 114 is designed to dissipate heat particularly effectively from the support 101 and, in the present example, is made of aluminum. Ideally, it has the largest possible surface area that physically contacts the support. A person skilled in the art can find further advantageous configurations and embodiments for implementing this model in WO 2020 / 152251 A1, for example.

[0130] Fig. 2a shows a carrier 101 according to the invention in plan view, i.e. from the perspective of the side of the carrier on which the plurality of first illuminants designed as LEDs are arranged. In the present example in Fig. 2a, first illuminants 102.1 and second illuminants 120 are provided. The first illuminants 102.1 are designed as UV-A LEDs in this example. The second illuminants 120 are designed as UV-B illuminants in this example. The example in Fig. 2a shows how a thermal analysis of a carrier 101 can be used to define isotherms 160. The isotherms 160 divide the surface of the carrier 101 into regions of essentially the same temperature according to defined parameters. It can be seen that a specific region has a highest temperature. This specific region determines the defined point on the carrier 101 on which the temperature sensor 103 is arranged.In the present example, the temperature sensor 103 is formed in the lower left quadrant of the carrier 101.

[0131] The defined point 150 lies in an area that is isothermally the warmest area on the carrier 101. The temperature sensor 103 is suitable for continuously measuring the actual temperature at the defined point 150 during operation. This actual temperature can be compared with the previously measured highest temperature at the defined area. From the actual temperature, an operating temperature of the UV LEDs 102.1, 120 can be derived. This derivation makes it possible to keep the operating temperature constant. For this purpose, a control unit (not shown in Fig. 2a) regulates the workload of a cooling system (not shown in Fig. 2a).

[0132] Fig. 2b shows an enlarged view of the quadrant with the temperature sensor 103 of the carrier 101 from Fig. 2a. The isothermal region in which the temperature sensor was placed can be seen. In this example, the temperature sensor is located between two UV LEDs of the same type, namely UV-A LEDs 102.1, 102.2. Also visible in the section is a UV LED of a second type, namely a UV-B LED 120.

[0133] Fig. 2c shows a device according to the invention as a complete LED module, schematically and by way of example. In the present example, we see the machine side of a carrier 101. In this example, the carrier 101 is an aluminum core carrier, as this is particularly well suited for dissipating waste heat. On the side facing away from the viewer, the carrier 101 has a plurality of first and second light sources (not shown) designed as LEDs.

[0134] A cooling system 108 is arranged on the support 101 and is controlled by a control unit 106. The control unit 106 controls the workload of the cooling system 108 depending on a measured temperature, as already described in the previous examples. The cooling system 108 essentially comprises two components. The cooling system 108 includes a fan 109 suitable for generating a ventilation flow. In addition, the cooling system 108 has a heat exchanger plate 114, which is arranged in contact with the support 101 and has a plurality of heat chambers 113.1, 113.4 that open into heat pipes 111.1, 111.2 and in which an intermediate fluid conducts the heat to the heat exchanger 110. The heat exchanger is made of aluminum for better heat transfer and has fins that increase the surface area for heat dissipation.

[0135] The heat exchanger plate 114 is also made of aluminum.

[0136] The LED module also has fastening means in the form of a fastening flange 116 and a locking tab 115, which are suitable for installing the LED module with a machine frame, for example in a housing of a solarium.

[0137] Example 1: Solarium with UVB LED modules

[0138] For flexible use, individual modules were created that include control electronics and monitoring sensors.

[0139] For use in solariums, several modules were combined to form module aggregates.

[0140] The connection to the device electronics includes the specification of setpoints (device to module) and the transmission of operating / error states (module to device). Several LED modules are combined into a module aggregate and can be operated with uniform setpoints. For example, it would be conceivable to distinguish between the upper part, the face area, and the lower part, although finer subdivisions are also possible. The modules can be operated with a fixed thermal operating point. This is defined as being above the highest expected room temperature.

[0141] In practical operation, the modules can initially be driven at low power until the heat dissipation of the LEDs has led to a corresponding increase in temperature. Then the power can be increased to the desired level, and the module can begin active cooling to maintain the temperature.

[0142] A higher temperature would also not be problematic from a safety perspective, since heating shifts the spectrum into the longer wavelength range and thus reduces the erythemal assessment.

[0143] The desired thermal operating point can also be taken into account during calibration. This allows, for example, the required operating parameters to be stored in the module software. When supplying the modules, it can also be ensured that only LEDs of a preferably uniform type are installed. Particular attention should be paid to the wavelength, or rather the bell curve, of the LED(s). This can be limited, for example, through pre-sorting.

[0144] In the present exemplary embodiment, control is via constant current. During module calibration, two control points with the associated performance data can be recorded and stored in the module software. During subsequent operation, the technical control for a desired setpoint can be calculated and adjusted independently.

[0145] To detect faulty control, the module monitors the current flow through the LEDs and compares it with the values ​​expected according to the calibration. If a deviation outside a tolerance limit occurs, the module switches off automatically and reports a corresponding error to the device. To detect component errors in current measurement, shutdown can also occur if the current is too low. To simplify operation, the modules are grouped together in units. Each unit represents a device area. All modules of a unit can be operated with the same setpoints. Fig. 3 shows a schematic of a possible control system structure in a device according to the invention. Both the number of modules and the number of units can vary. The connections shown indicate the data flow of the software communication. Electrical connections are not shown.

[0146] The module electronics include a controller that provides communication with the device. This controller can convert the general setpoints into specific control signals for the module electronics. The software can also monitor and / or control the thermal operating point.

[0147] Fig. 4 shows a schematic diagram of a module. The number of LEDs or LED blocks can vary depending on the module type.

[0148] It is conceivable that a module contains several power sources for the simultaneous operation of different LEDs.

[0149] Independent control and monitoring can be provided for each LED type. It is particularly preferable to define the thermal operating point the same for all modules.

[0150] List of reference symbols

[0151] 1 Device control

[0152] 2.1 first modular unit

[0153] 2.2 second modular unit

[0154] 3 LED modules

[0155] 3.1 first LED module

[0156] 3.2 second LED module

[0157] 3.n LED modules

[0158] 10 Cooling unit 11 Power source

[0159] 12 Current measurement

[0160] 13 Temperature sensor

[0161] 14 Control unit

[0162] 15 Module interface

[0163] 16 LED array

[0164] 17 LED

[0165] 100 LED modules

[0166] 101 carriers

[0167] 102. n first light source(s)

[0168] 103 Temperature sensor

[0169] 106 Control unit

[0170] 108 Cooling system

[0171] 109 Heat dissipation element / ventilation

[0172] 111. n heat segment(s)

[0173] 112. n heat pipe(s)

[0174] 113. n Heat chamber(s) 114 Heat exchanger plate

[0175] 120. n second lamp(s)

[0176] 150 defined point on the carrier

[0177] A electromagnetic radiation

Claims

Patent claims 1. A device for irradiating at least part of a human or animal body with electromagnetic radiation, in particular with actinic radiation, comprising: a. a plurality of first lighting means (102, 102.1, ..., 102.4) designed as LEDs, arranged on a carrier (101); b. a temperature sensor (103) arranged at a defined point (150) on the carrier (101) for measuring an actual temperature at the defined point; c. a cooling system (108) for directly and / or indirectly dissipating heat from the carrier (101), and d. a control unit (106) for controlling an operating temperature of the plurality of first lighting means (102, 102.1, ..., 102.4) designed as LEDs as a function of the measurement of the actual temperature at the defined point (150).

2. Device according to claim 1, wherein the defined point (150) on the carrier (101) is an experimentally determined point on the carrier (101).

3. Device according to claim 2, wherein the defined point (150) on the carrier (101) lies in a region of the highest measured isotherms of the carrier.

4. Device according to one of claims 1 to 3, further comprising a plurality of second lighting means (120) designed as LEDs.

5. Device according to one of claims 1 to 4, wherein the carrier is formed as a substantially flat plate and divides a space into an irradiation zone and a machine zone.

6. Device according to claim 5, wherein the plurality of first lighting means (102, 102.1, ..., 102.4) designed as LEDs, in particular also the plurality of second illuminating means (120) designed as LEDs are arranged on the carrier in such a way that they are able to emit electromagnetic radiation into the irradiation zone for irradiation, and the cooling system is arranged on the machine zone relative to the carrier (101).

7. Device according to one of claims 1 to 6, wherein the cooling system comprises at least one, in particular a plurality of, heat pipe(s) (112.1, 112.2) which bring a heat dissipation element (109) into operative connection with a heated region of the carrier, in particular wherein the heat dissipation element (109) comprises a ventilation (109).

8. A method for operating a device for irradiating at least part of a human or animal body with electromagnetic radiation, in particular with actinic radiation, in particular for operating a device according to one of claims 1 to 7, comprising the steps: a. measuring an actual temperature at a defined point (150) on a carrier (101) which comprises a plurality of first lighting means (102, 102.1, ..., 102.4) designed as LEDs; b. comparing the actual temperature with an experimentally determined target temperature which is indicative of an operating temperature of the warmest lighting means in operation of the plurality of first lighting means (102, 102.1, ..., 102.4) designed as LEDs; c. regulating an output of a cooling system for the direct and / or indirect heat dissipation from the carrier (101) as a function of b).

9. The method according to claim 8, wherein the control is designed to maintain a constant operating temperature of each of the plurality of first lighting means (102, 102.1, ..., 102.4) designed as LEDs, in particular a constant operating temperature in a range of between 50 and 60 degrees Celsius, in particular of approximately 55 degrees Celsius.

10. Method according to one of claims 8 or 9, wherein the control of the working power of the cooling system comprises controlling a rotational speed of a flow fan, in particular a fan.

11. The method according to any one of claims 8 to 10, wherein the method comprises determining the defined point.

12. Method according to one of claims 8 to 11, wherein the method comprises the step: d. Regulating an operating power of one, several or all of the plurality of first lighting means (102, 102.1, ..., 102.4) designed as LEDs as a function of b).

13. Method according to one of claims 8 to 12, further comprising the step: e. Determining an actual temperature of each and / or the warmest of the plurality of first illuminating means (102, 102.1, ..., 102.4) designed as LEDs on the basis of the actual temperature measured in a) at the defined point (150) on the carrier (101).

14. A method for operating light-emitting diodes, in particular UV light-emitting diodes for use in devices according to one of claims 1 to 7, in particular for irradiating at least a part of a human or animal body with electromagnetic radiation in the wavelength range of less than 380 nm, comprising the steps: a. Providing at least one first LED module (100) with a plurality of light-emitting diodes with a first spectral composition; b. Recording a plurality of performance data of the first LED module and storing the recorded performance data; c. Defining a thermal operating point, wherein the thermal operating point is selected such that it lies above the highest expected room temperature at which the device is to be operated; d. Monitoring the current flow through the majority of LEDs and comparing it with the performance data from b).

15. The method according to claim 14, wherein the providing according to a) comprises providing a plurality of light-emitting diodes having a first spectral composition with a peak wavelength in a specific bell curve wavelength range, in particular a specific bell curve wavelength range with a full width half maximum (FWHM) of about 0.5 nm to 20 nm, in particular of about 1 nm to 20 nm.

16. The method according to claim 14 or 15, wherein the monitoring and comparison according to d) comprises switching off the first LED module in the event of a predefined deviation.

17. Method according to one of claims 14 to 16, wherein at least one second LED module, in particular a plurality of LED modules, is provided according to a).

18. The method according to any one of claims 14 to 17, wherein the method further comprises the step: e. Cooling the first module after reaching the thermal operating point.

19. Method according to one of claims 14 to 18, wherein the electromagnetic radiation is designed for cosmetic purposes, in particular with a first spectral composition in the UV-B range, in particular between 280 nm and 320 nm.

20. Device for operating light-emitting diodes, in particular UV light-emitting diodes, for use in devices for irradiating at least a part of a human or animal body with electromagnetic radiation, in particular electromagnetic radiation in the wavelength range of less than 380 nm, in particular for operating light-emitting diodes with a method according to one of claims 14 to 19, the device comprising: a. at least one first LED module with a plurality of light-emitting diodes with a first spectral composition, in particular with a peak wavelength in a specific bell curve wavelength range, in particular a specific bell curve wavelength range with a full width half maximum (FWHM) of approximately 0.5 nm to 20 nm, in particular of approximately 1 nm to 20 nm, and b. at least one exposure chamber for accommodating at least a part of a human or animal body, wherein the exposure chamber comprises an effective area which can be exposed to electromagnetic radiation by the at least one first LED module.

21. Device according to claim 20, wherein the plurality of light-emitting diodes with a first spectral composition have a peak wavelength in a specific UV-B wavelength range, in particular in a range of between 280 nm and 320 nm.

22. Device according to claim 20 or 21, wherein the at least one first LED module, in particular each LED module, comprises a control unit for controlling the light-emitting diodes with a first spectral composition on the respective module.

23. Device according to one of claims 20 to 22, wherein the at least one first LED module, in particular each LED module, comprises a sensor unit for measuring operating parameters of the light-emitting diodes with a first spectral composition on the respective module, in particular for measuring the temperature and / or the light-emitting diodes.

24. Device according to one of claims 20 to 23, wherein the at least one first LED module, in particular each LED module, comprises a module interface for connection to a device controller, in particular for specifying setpoints from the device controller to the control unit of the module and / or for transmitting operating / error states from the control unit of the module to the device controller.

25. Device according to one of claims 20 to 24, wherein a plurality of LED modules are combined to form a module aggregate, in particular wherein each module aggregate is designed to act on a part of a human or animal body, wherein the part of a human body is selected from the group consisting of: upper body, in particular torso, in particular arms, in particular shoulders, in particular hands, head, in particular face and lower body, in particular loins, in particular legs, in particular feet.

26. Device according to one of claims 20 to 25, wherein the LED modules are designed to be interchangeable.

27. A solarium comprising: a. At least one device according to claim 1, and b. A device according to claim 20.

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