FIELD OF THE INVENTION

The present invention relates to a disinfecting device having an improved lifetime and safety. The disinfecting device can also have an improved aesthetic appearance. The disinfecting device is particularly suitable for upper air disinfection in a room.

BACKGROUND OF THE INVENTION

In view of the recent development in the world concerning the global Covid 19 pandemic, disinfection has become a topic of renewed interest as the demand for sterilization increases. One way of disinfecting involves the use of UV light As a response to pathogenic outbreaks involving airborne microorganisms it would be beneficial to employ UV light for disinfecting air and objects at locations where the transmission of such microorganisms is believed to occur.

Disinfecting luminaires are used to flood spaces such as hospital rooms with UV-B radiation (ultra-violet light having a wavelength between 280 nanometer and 315 nanometer (nm)) and UV-C radiation (ultra-violet light having a wavelength between 100 nm and 280 nm) for disinfection purposes. Such disinfecting luminaires requires a relatively brief time, e.g. several minutes, to achieve adequate disinfection but require the room to be evacuated of people. This is because UV light, and in particular UV-C radiation, has a range of effectiveness which interferes and destroys nucleic acids of bacteria and other microbes, but can also damage human cells. Another type of disinfecting luminaire uses a fixed 405 nm violet light source to provide disinfection without the need to evacuate people from the room. However, such luminaires may require hours to achieve adequate disinfection since violet light is less effective at killing pathogens compared to UV-B and UV-C radiation, and since the light is dispersed over a wide area such that the irradiance level is relatively low.

Normally, disinfection by UV light sources is used under controlled conditions, such as within disinfection chambers wherein objects to be disinfected can be placed, or in areas where humans and/or animals are not present during ongoing disinfection, such as surgery theaters or the like. WO2021/247116 discloses a disinfection chamber wherein objects to be disinfected can be placed. The chamber is then closed during the disinfection process, so that safety for the operator is guaranteed. The chamber comprises at least one UV light source and a reflective element capable or reflecting at least 75% nominal reflectance of UV-C, so as to direct the UV radiation towards the object to be disinfected.

However, the increased demand for germicidal activities may involve operating UV light sources in environments with human presence, thus introducing a risk for unintentional irradiation by UV light. Therefore, so-called upper air disinfecting devices have been developed. Such devices can be mounted on the ceiling and emit UV-C radiation which is collimated to be distributed and to remain in the upper air of the room, i.e. the air arranged in vicinity of the ceiling, where people usually are not present. Hence, the risk for potential exposure of humans or animals to the harmful irradiation is largely reduced. In particular, upper air disinfection devices comprise a light absorbing louver which allows to control the spatial light distribution. The louver removes harmful UV-C radiation or light emitted at higher angles and only allows predominantly horizontally arranged rays to be emitted (so- called collimation of the UV radiation).

US2014/0084185 discloses a disinfecting device that can be used for upper air disinfection. The device comprises a UV light source and 2 pairs of parabolic reflectors which are positioned and designed to collimate and reflect the UV light towards a louver comprising a plurality of lamellae or baffles. The design and positioning of the pairs of reflectors allows to increase the amount of effective UV radiation emitted into the room (thus exiting the device), which increases the efficiency of the device.

However, the louvers of such disinfection devices are currently made from a metal that is coated with a layer of a UV light absorbing materials. Such a layer comprises typically a polymer layer with embedded particles, wherein the embedded particles have UV radiation/light absorbing properties. One of the disadvantages of such layers is that they suffer from degradation, such as degradation of the polymer and/or particles, which, in itself, does not have sufficient UV light resistant properties. Consequently, degradation of the coating layer leads to increased UV reflection over time, instead of absorption, which leads to unsafe situations as UV light emitted from the device is no longer collimated enough to be distributed only in the upper air of the room. For example, parts and/or powder may be released from the surface of the louver/metal. Further, degrading layers may require substantial maintenance to repair or replace, leading to downtime of the device and reduction of efficiency and efficacy. Yet another disadvantage is that such coating layers are often considered to be not aesthetically appealing, in particular when the pigments used comprise black dye.

Hence, it is of interest to provide alternatives to the disinfection devices of the prior art in order to improve their lifetime, safety over time, and their aesthetic appearance.

SUMMARY OF THE INVENTION

It is an object of the present invention to overcome one or more of the drawbacks of the prior art. It is an aim of the present invention to provide a disinfecting device, in particular suited for upper air disinfection, which provides stable UV light absorption over a prolonged time, thereby ensuring sufficient collimating of the UV light emitted from the device and thus providing safety to the users over a prolonged time. It is a further aim to provide a disinfecting device that has an improved lifetime, and/or requires less frequent maintenance.

According to a first aspect of the present invention, there a disinfecting device is provided. Disinfecting devices of the present invention may be particularly suitable for disinfecting spaces with a high level of activity, such as a waiting room in a hospital or a veterinary clinic, a public space such as a library, an office, a department store or the like, as well as public transportation means, such as busses, trams, trains or metros.

Throughout the description, directions will be addressed as “downward” and “upward”. In the context of the present invention, the term “downward direction” is to be understood as a direction aligned with a vector of gravitational acceleration. The vector of gravitational acceleration may be understood as being a gravitational acceleration vector of a celestial body, e.g. the Earth, on which the disinfecting device is arranged or located. It is intuitively understood that the term “upward direction” is the direction being opposite to the downward direction, i.e. a direction arranged 180° from the downward direction.

According to a first aspect of the invention, there is thus provided a disinfecting device according to the appended claims. The disinfection device is advantageously used for upper air disinfection.

The disinfecting device comprises at least one light source arranged for, in operation, emitting UV light. The light source may be any light source configured to emit light having a high germicidal effect. In the context of the present invention, the UV- spectrum comprises any electromagnetic radiation with a wavelength between 100 nm and 400 nm. The UV wavelength range may be between 100 nm and 280 nm, i.e. the UV-C wavelength range. Alternatively, or additionally, the UV wavelength range may be between 280 nm and 315 nm, i.e. the UV-B wavelength range. Alternatively, or additionally, the UV wavelength range may be between 315 nm and 400 nm, i.e. the UV-A wavelength range. The UV light may be omnidirectional, i.e. may be emitted 360 ⁰ from the at least one light source.

The light source may be a solid-state light source such as a light-emitting diode, LED, and/or a laser diode. Further, the light source may be a low pressure mercury plasma lamp or an excimer light source. The light source may comprise a plurality of LEDs, each of which emits at least one of: UV-C radiation (100 nm-280 nm); UV-B radiation (280 nm-315 nm); or UV-A radiation (315 nm-400 nm). By the term “plurality” in the context of the present invention is meant two or more.

The term “LED” as used in the context of the present invention implies any type of LED known in the art, such as inorganic LED(s), organic LED(s), polymer/polymeric LEDs, violet LEDs, blue LEDs, optically pumped phosphor coated LEDs, optically pumped nano-crystal LEDs. As used herein, the term “LED” can encompass a bare LED die arranged in a housing, which may be referred to as a LED package. When UV-C light is used, the LED may be mounted in a cavity covered in a non-contact manner by an emission window made from quartz/fused silica.

The plurality of LEDs may comprise at least 10 LEDs, preferably at least 20 LEDs, more preferably at least 30 LEDs.

The disinfecting device according to the present invention may comprise a plurality of light sources, each providing an UV light. The wavelengths of the UV light emitted from each light source may be same or different. For example, the disinfecting device may comprise three light sources, wherein the first one of the light sources emits light within the UV-C spectrum, the second one of the light sources emits light within the UV-B spectrum, and the third one of the light sources emits light within the UV-A spectrum. The various light sources might be used together or might be operated individually, depending on the type of microbiological species that needs to be deactivated.

The disinfecting device of the present invention further comprises at least one louver. The louver comprises a plurality of substantially parallel light absorbing structures. In particular, the plurality of substantially parallel light absorbing structures may comprise N light absorbing structures, wherein N is an integer being equal to or greater than 3, preferably equal to or greater than 5, more preferably equal to or greater than 7, even more preferably equal to or greater than 8, such as equal to or greater than 9 or equal to or greater than 10, most preferably equal to or greater than 12. Each one of the plurality of light absorbing structures has a first surface and a second surface being opposite to the first surface. Each one of the plurality of light absorbing structures further has a proximal end being arranged adjacent to the at least one light source, and a distal end being arranged opposite to the proximal end.

The plurality of light absorbing structures further has a longitudinal extension between the proximal end and the distal end, and a transversal extension being substantially perpendicular to the longitudinal extension.

The disinfecting device may be attached to a mounting surface, such as a ceiling or a wall. In such an embodiment, the first surface and the second surface are advantageously arranged substantially parallel to the mounting surface. Alternatively, the disinfecting device may be arranged such that the first and the second surface are substantially perpendicular to the mounting surface, e.g. in an embodiment when the mounting surface is a table, a floor, a shelf, or the like.

The light absorbing structure can have the form or shape of a plate, a cylinder, a triangular prism, a cuboid, a pentagonal prism, a hexagonal prism, or the like. The shape of each light absorbing structure may be same as or different from the shape of the other light absorbing structures. Advantageously, the plurality of substantially parallel light absorbing structures has substantially the same shape. In a particularly preferred embodiment, the plurality of substantially parallel light absorbing structures is in the form of N substantially parallel plates, wherein N is as defined above. A plate-shaped light absorbing structure is also known in the field as a lamellae.

The plurality of substantially parallel light absorbing structures may be connected. For example, they may form a single unit, a single piece, for example a honeycomb structure or a grid structure.

The light absorbing structures according to the present invention are arranged for absorbing a first portion of the UV light. The first portion of the UV light may preferably be at least 10%, more preferably at least 15%, most preferably at least 20% of the total amount of the first light. Further, the first portion may preferably be less than 35%, more preferably less than 30%, most preferably less than 25% of the total amount of the first light.

At least one of the plurality of light absorbing structures comprises an anodized metal part which comprises a porous metal oxide layer, the pores of which are at least partially filled with a compound capable of absorbing UV light. The anodized metal part can comprise or substantially consist of aluminium, zinc, titanium, an alloy comprising aluminium, an alloy comprising zinc, an alloy comprising titanium, or combinations of two or more thereof. Alloys comprising aluminium, zinc or titanium can further comprise silicon (e.g. an aluminium-silicon alloy), chromium and manganese.

When two or more of the plurality of light absorbing structures comprises an anodized metal part, it can be the same or a different anodized metal part. Advantageously, the light absorbing structures comprise or substantially consist of the same anodized metal. In a particular embodiment, they can all comprise or substantially consist of aluminium. Advantageously, all of the plurality of light absorbing structures comprises an anodized metal part which comprises a porous metal oxide layer, the pores of which are at least partially filled with a compound capable of absorbing UV light.

Advantageously, when the louver comprises N substantially parallel light absorbing structures, 1 to N light absorbing structures comprises an anodized part which comprises a porous metal oxide layer, the pores of which are at least partially filled with a compound capable of absorbing UV light. Advantageously, at least 10 %, preferably at least 20 %, more preferably at least 50 %, for example at least 75 %, at least 80 %, more preferably at least 90 % of the light absorbing structures comprises an anodized part which comprises a porous metal oxide layer, the pores of which are at least partially filled with a compound capable of absorbing UV light. For example, when N is 10, preferably at least 2, at least 5, more preferably at least 8, or at least 9, or at least 10 of the light absorbing structures comprises an anodized part which comprises a porous metal oxide layer, the pores of which are at least partially filled with a compound capable of absorbing UV light.

In a particular embodiment, all of the plurality of (substantially parallel) light absorbing structures comprise an anodized metal part, which comprises or substantially consists of aluminium, comprising a porous metal oxide layer, which comprises or substantially consists of aluminium oxide.

The porous metal oxide layer can be provided on at least part of the first surface and/or at least part of the second surface of the light absorbing structure. For example, the porous metal oxide layer can be provided onto the entire first surface only, or on both the entire first surface and the entire second surface. Advantageously, and preferably, the porous metal oxide layer is provided on the entire first surface and the entire second surface of the light absorbing structure.

Advantageously, the compound capable of absorbing UV light is present on at least part of the first surface and/or at least part of the second surface of the light absorbing structure. With “at least part” is meant in the light of the present invention at least 5 % of the surface area, preferably at least 10 %, such as at least 20 %, at least 25 %, at least 30 %, at least 40 %, at least 50 %, at least 60 %, at least 70 %, at least 75 %, at least 80 %, more preferably at least 90%, such as 92 %, 95 % or 98 %. Advantageously, the compound is present on substantially the entire first surface and/or of substantially the entire second surface comprising an anodized metal part comprising a porous metal oxide layer.

The compound capable of absorbing UV light can be capable of absorbing a portion of the wavelength range of UV light. For example, the compound can be chosen so that it absorbs UV light in the wavelength range of UV-A only. For example, when the light source emits UV-C light having a wavelength between 100 nm and 280 nm, the compound is advantageously capable of absorbing said UV-C light.

Preferably, the metal surface is cleaned, and a next step is to build up a layer of metal oxide on the metal surface. Advantageously, at least the metal surface of the substrate is suspended (e.g. immersed or submersed) in a tank of electrolyte (for example comprising sulfuric acid) and an electric current is applied so as to produce (micro)pores in the metal surface of the substrate. It is known in the art that the size and shape of the pores depends on the metal or metal alloy of the metal surface. The formed pores are filled with free oxygen ions in the electrolyte, thereby creating a strong yet porous oxide layer.

The pores of the porous metal oxide layer can be filled with the compound by any method or combination of methods known in the art. Examples of such methods include, without being limited thereto, mineral pigmentation, immersion of the porous metal oxide layer in a solution comprising the compound (i.e. dip colouring), spraying the compound on the metal oxide layer, electrolysis of the porous metal oxide layer in a solution comprising one or more metal salts (i.e. electrolytic coloring). Electrolytic coloring comprises immersion of the porous metal oxide layer (e.g. by immersing the substrate) in a solution comprising at least one metal salt. The metal salt typically fills the pores. The resulting coating is typically very strong and is capable of resisting UV fading. However, but the colors that can be realised by electrolytic coloring are usually limited to a bronze or a black color. Dip coloring comprises placing the porous metal oxide layer (e.g. the substrate) in a tank of dye. The dye is absorbed into the pores. The surface is then boiled in de-ionized water to halt any further reactions. There are many color choices with this method, however the colors are typically not UV resistant, causing them to fade over time.

The compound capable of absorbing UV light can be any type of compound suitable, for example an organic compound, an inorganic compound, or combinations thereof. Advantageously, the compound capable of absorbing UV light is an inorganic compound. Examples of suitable compounds include, without being limited thereto, barium sulphate, lead chromate, cobalt sulphide, ferric ferrocyanide, ferric ammonium oxalate, or combinations thereof.

When two or more of the plurality of light absorbing structures comprises a porous metal oxide layer at least partially filled with such a compound, the compound can be the same or can be different.

Advantageously, the compound capable of absorbing UV light is also capable of absorbing a part of the visible light. In the present context, visible light comprises any electromagnetic radiation with a wavelength between 380 nm and 750 nm. Advantageously, or additionally, the compound is also capable of reflecting a part of the visible light. Advantageously, the compound capable of absorbing UV light is capable of absorbing a part of the visible light and reflecting another part of the visible light. Consequently, according to the human eye, the light absorbing structure will have a colour. The colour is a combination of the colour of the porous metal oxide and the compound used to at least partially fill the pores thereof. By varying the metal of the porous metal oxide and the compound, a wide range of colours can be obtained, thereby providing an aesthetically attractive disinfecting device.

For example, when the compound substantially consists of barium sulphate, the colour as seen by the human eye will be white or close to white (e.g. so-called off-white). When the compound substantially consists of lead chromate, the colour will be yellowish. When the compound substantially consists of cobalt sulphide, the colour will be blackish. When the compound substantially consists of ferric ferrocyanide, the colour will be blueish. When the compound substantially consists of ferric ammonium oxalate, the colour will be a metallic gold.

When two or more of the plurality of light absorbing structures comprise a different compound, each compound being capable of absorbing a part and reflecting another part of the visible light, the light absorbing structures will, to the human eye, have a different colour, i.e. the louver will be seen as having multiple colours. When all light absorbing structures comprise the same compound, each compound being capable of absorbing a part and reflecting another part of the visible light, the light absorbing structures will, to the human eye, have the same colour, i.e. the louver is seen as having a single colour. This allows to obtain aesthetically attractive disinfecting devices, having a variety of colours.

The porous metal oxide layer which is at least partially filled with a compound as described above can further comprise a sealing arranged for sealing, i.e. closing off, said at least partially compound filled porous metal oxide layer. Sealing is advantageously performed by boiling the metal surface with its porous oxide layer in pure distilled or demineralised water for between 5 minutes and 60 minutes, such as between 15 minutes and 45 minutes, preferably about 30 minutes, for producing metal hydrate nanoparticles (e.g. aluminium hydrate nanoparticles when the metal surface comprises aluminium) which cover the top surface. It is also possible to apply an organic or inorganic top layer for covering the top of the porous structure using known techniques such as physical vapour deposition and applying a coating.

The disinfecting device according to the present invention further comprises at least one optical element arranged to collimate at least part of the UV light emitted from the light source. Advantageously, the optical element is a collimator. The collimator may comprise or may be, without being limited thereto, a lens, an array of lenses, a reflector, or a total internal reflection optical element (TIR optic).

Advantageously, the collimated UV light is collimated towards the louver. In other words, the part of the UV light emitted by the light source that interacts with the at least one optical means, e.g. collimator, is collimated, while the remaining part of the UV light emitted towards the louver will not be collimated. Thus, the UV light emitted by the at least one light source and collimated by the optical element (collimator) will be directed towards the plurality of light absorbing structures as a collimated beam comprising predominantly parallel rays of the UV light.

Advantageously, the collimated beam of UV light is substantially parallel to the longitudinal extension of the plurality of light absorbing structures, for example a plurality of lamellae, and therefore will spread minimally as it propagates, thus minimizing dispersion with distance. As intuitively understood, and consequently, a substantial portion of the UV light will be transmitted through said louver without impinging on one or more of the light absorbing structures. Hence, this portion of the UV light will be emitted by the disinfecting device in a direction being substantially in plane with the longitudinal extension of the light absorbing structure in the case of lamellae.

However, since a perfect collimation is prevented by diffraction, the beam of the UV light collimated by the at least one optical element will comprise rays being nonparallel to the longitudinal extension of the plurality of light absorbing structures. Advantageously, and consequently, the plurality of light absorbing structures are provided so that at least part, and preferably substantially all, of the nonparallel rays will interact with the first and/or the second surface of one or more light absorbing structures. Consequently, at least a first portion of these rays of the UV light will be absorbed by the plurality of the light absorbing structures according to the invention. The louver is thus capable to remove harmful UV light emitted at higher angles and to allow only predominantly horizontally arranged rays of UV light to be emitted.

The optical element can collimate the part of the UV light emitted by the light source that interacts with the optical element by absorbing part thereof and/or by reflecting another part thereof. For example, the optical element can be arranged to absorb incident UV rays having an angle making it difficult to collimate well the UV rays, and to reflect UV rays having an incident angle allowing for collimation of good quality. By doing so, the amount of the collimated UV light collimated towards the louver that is absorbed by the plurality of light absorbing elements can be reduced.

Such an embodiment can be realized by providing the optical element with one or more areas capable for absorbing UV light. For example, the optical element can comprise one or more portions comprising an anodized metal part comprising a porous metal oxide layer, wherein the pores of said porous metal oxide layer are at least partially filled with a compound capable of absorbing UV light. Advantageously, such anodized metal parts are as described hereinbefore.

The disinfecting device may further comprise a housing comprising a light exit window. In the context of the invention a light exit window is to be interpreted as any area, volume, or material which allow light to pass through it. The housing may be a hermetic housing. The at least one light source, the at least one louver and the at least one optical element (collimator) may be arranged inside the housing. The housing may have any geometrical shape. The housing may be formed as a cuboid, where at least one face of the cuboid may act as a light exit window from where light can be emitted. The housing may further comprise an attachment surface arranged to be positioned on the surface to which the housing is to be attached, such as a ceiling, a floor, a wall, a table, or another suitable surface in a room.

The disinfecting device may further comprise a UV light sensor arranged for determining the intensity of output UV light and its distribution within the room. This should not be considered as excluding other sensor types as presented in this disclosure.

According to a second aspect of the present invention, a luminaire is provided. The luminaire comprises or substantially consists of a disinfecting device according to the first aspect of the invention. For example, the disinfecting device according to the present invention may be a luminaire. The luminaire can further comprise mounting means for mounting the luminaire to a mounting surface. The luminaire is advantageously used for upper air disinfection. As mentioned above, when the mounting surface is a wall or a ceiling, the longitudinal extension of the plurality of light absorbing structures will be substantially parallel to the mounting surface. When the disinfecting device in the form of a luminaire is mounted on a wall, the light exiting the disinfecting device shall be directed upwards towards the ceiling of the room in order to avoid accidental exposure of a subject to the harmful UV light. The disinfecting device may be configured to suspend from a ceiling of a room by a suspension arrangement or may be attached to the ceiling.

Alternatively, the mounting surface may be the floor or a piece of furniture, such as a tabletop, a shelf, or the like. In such an embodiment, the longitudinal extension of the light absorbing structure will be substantially perpendicular to the mounting surface. Even in this case, the light exiting the disinfecting device will be directed upwards towards the ceiling of the room.

Finally, a plurality of disinfecting devices may be arranged at different locations within the same room in order to increase disinfection rate and capacity.

According to the present invention, the safety of the disinfecting device is increased. Like already available disinfecting devices, the potentially harmful UV light, in particular UV-C light, is prevented from exiting the disinfecting device at undesired angles, thus minimizing the risk of unintentional exposure of humans and/or animals to damaging irradiation. Further, the light absorbing structures as described above increase the safety of the louver, and of the disinfecting device, because the compounds capable of absorbing UV light are stable and do not degrade easily. This prolongs the reliability and the lifetime of the device and reduces the downtime. This also maintains the efficiency of absorbing UV light that would exit the disinfecting device at undesired angles, thereby maintaining a high level of safety for an increased period of time.

BRIEF DESCRIPTION OF THE DRAWINGS

This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing non-limiting embodiment(s) of the invention.

Fig. 1 shows a cross-sectional view of a disinfecting device according to the present invention.

Fig. 2 shows a cross-sectional view of a light absorbing structure of a disinfecting device according to the present invention. Fig. 3 shows a cross-sectional view of a further embodiment of a light absorbing structure according to the present invention.

Fig. 4 shows a cross-sectional view of a further embodiment of the disinfecting device according to the invention.

All the figures are schematic, not necessarily to scale, and generally only show parts which are necessary in order to elucidate embodiments of the present invention, wherein other parts may be omitted or merely suggested.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention will now be described hereinafter with reference to the accompanying drawings, in which exemplifying embodiments of the present invention are shown. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments of the present invention set forth herein; rather, these embodiments of the present invention are provided by way of example so that this disclosure will convey the scope of the invention to those skilled in the art. In the drawings, identical or similar reference numerals denote the same or similar components having a same or similar function, unless specifically stated otherwise.

Fig. 1 illustrates a cross-sectional view of a disinfecting device 1 The disinfecting device 1 comprises one light source 2 arranged for, in operation, to emit a UV light. The disinfecting device 1 further comprises a louver 4 comprising six light absorbing structures 5 each having a first surface 6 and a second surface 7 being opposite to the first surface 6. The light absorbing structures 5 further have a proximal end 8 being arranged adjacent to the light source 2, and a distal end 9 being arranged opposite to the proximal end 8. The light absorbing structures 5 further have a longitudinal extension (not shown) between the proximal end 8 and the distal end 9, and a transversal extension being substantially perpendicular to the longitudinal extension. The light absorbing structures 5 are in the form of stacked plates which are arranged in a substantially parallel way.

The light absorbing structure 5, and preferably all light absorbing structures 5, may have a high aspect ratio, e.g. an aspect ratio of at least 2, preferably at least 3, more preferably at least 4, most preferably at least 5. By the term “aspect ratio” in the context of the present invention is understood the ratio between the longitudinal extension and the transversal extension of the light absorbing structure 5.

The disinfecting device 1 further comprises a collimator 3 arranged to collimate a part of the UV light emitted from the light source 2 towards the louver 4. The collimator 3 as shown is a reflector. The UV light emitted by the light source 2 will be directed towards the light absorbing structures 5 as a collimated beam comprising predominantly parallel rays of the UV light. The collimated beam of UV light is substantially in plane with the longitudinal extension of the light absorbing structures 5.

As mentioned above, the plurality of substantially parallel light absorbing structures 5 are arranged to absorb a portion of the (collimated) UV light. In particular, the portion of the UV light comprising not predominantly parallel rays of UV light is advantageously absorbed by the light absorbing structures 5.

To this end, and referring to Fig. 2, at least one of the light absorbing structures 5 comprises an anodized metal part 20 comprising a porous metal oxide layer 21. The pores 22 of the porous metal oxide layer 21 are at least partially filled with a compound 23 capable of absorbing UV light. The compound 23 capable of absorbing UV light is as described above.

Such an anodized metal part 20 comprising a porous metal oxide layer 21 having pores 22 which are at least partially filled with a compound 23 capable of absorbing UV light can be obtained by methods known in the art. A particularly preferred method comprises first a pre-treatment of a metal part. The pre-treatment can include one or more of cleaning, etching or desmutting the metal part, such as a metal plate. The pre-treated metal part is then anodized, thereby obtaining an anodized metal part 20 comprising a porous metal oxide layer 21. In a next step, the pores 22 of the porous metal oxide layer 21 are at least partially filled with the compound 23.

Further, and referring to Fig. 3, the light absorbing structure 50 can further comprise a sealing 24. The sealing 24 closes off, i.e. seals, the pores 22 of the porous metal oxide layer 21. Advantageously, the sealing 24 protects the compound 23, and thereby the porous metal oxide layer 21 and the part of the light absorbing structure 50 comprising the compound 23 against humidity, dirt, dust, and the like. Further, the sealing 24 allows for easier cleaning of the light absorbing structures 50.

The sealing can be done by boiling the metal oxide layer in pure distilled water for about 30 minutes to produce hydrated metal nanoparticles sealing the top surface. Sealing can also comprise materials known in the art which are resistant against the UV light emitted by the light source, such as one or more of UV-A light, UV-B light and UV-C light. The sealing is further advantageously resistant against visible light, having a wavelength in the range as defined above. The sealing is advantageously at least partially transparent to the UV light emitted by the light source, preferably at least 75 % transparent, more preferably at least 90 % transparent, most preferably substantially entirely (100 %) transparent to the UV light emitted by the light source. This allows the collimated UV light which needs to be absorbed, e.g. because of an unfavourable angle, to be efficiently absorbed by the compound 23, and thus by the light absorbing structure 50, thereby ensuring the safe, efficient and proper functioning of the disinfecting device 1.

Referring back to Fig. 1, the compound capable of absorbing UV light is present on substantially the entire first surface 6 and substantially the entire second surface 7 of the light absorbing structure 5. Further, all of the plurality of substantially parallel light absorbing structures 5 comprise the anodized metal part 20 comprising a porous metal oxide layer 21, wherein the pores 22 of the porous metal oxide layer 21 are at least partially filled with the compound 23.

Fig. 4 shows a further embodiment of the disinfecting device 100. The disinfecting device 100 comprises one light source 2, a collimator 3, and a louver 4 comprising a plurality of substantially parallel light absorbing structures 5 having a first surface 6, a second surface 7, a proximal end 8 and a distal end 9 as the disinfecting device 1 of Fig. 1.

The disinfecting device 100 further comprises at least one, and as shown in Fig. 4, a plurality of light converting elements 10 arranged for converting a further portion of the UV light emitted by the light source 2 into a second light having a second wavelength range comprising different wavelengths than the wavelength range of the UV light emitted by the light source 2. Advantageously, the light converting element 10 is arranged for converting a further portion of the UV light emitted by the light source 2 into a second light having a second wavelength range comprising longer wavelengths than the wavelength range of the UV light emitted by the light source 2. The second portion of the first light may preferably be at least 10%, more preferably at least 15%, most preferably at least 20% of the total amount of the first light. Further, the second portion of the first light may preferably be less than 35%, more preferably less than 30%, most preferably less 25% of the total amount of the first light. It must be noted that the second portion of the first light is different from the first portion of the UV light that is absorbed by the plurality of light absorbing structures 5.

In other words, the portion of the first light consisting of rays of the first light being non-parallel to the longitudinal extension of the light absorbing structure comprises a first portion and a second portion, wherein the first portion is absorbed by the plurality of light absorbing structures, and the second portion is converted into a second light having a second wavelength range comprising different, preferably longer, wavelengths than the first UV wavelength range. In particular, the second light may have a major wavelength peak in the second wavelength range.

As the result, the light emitted by the disinfecting device of the present invention will comprise the first light having a first UV wavelength range, and a second light having a second wavelength range comprising different, preferably longer, wavelengths than the first wavelength range.

Hence, the light converting element 10 allows to convert a portion of the UV light emitted by the light source 2 into a less harmful second light, such as UV-A light, UV-B light, visible light, or a combination of two or more thereof. UVA and/or UV-B light are less damaging compared to the UV-C light and may be used for disinfection purposes at wider angles. The visible light may be used for alerting the user that the disinfection device is operating. Alternatively, or additionally the visible light may be used for general illumination, and may thus provide an aesthetically appealing effect.

As shown in Fig. 4, all of the plurality of light absorbing structures 5 comprises a light converting element 10 at the first surface 6 and at the second surface 7, wherein the light converting elements 10 are arranged at the distal end 9 of the light absorbing structures 5. As will be understood, it is possible to provide light converting elements 10 on one or more of the light absorbing structures 5, as well as at different locations of the first surface 6 and/or the second surface 7 (not shown).

Although the present invention has been described with reference to various embodiments, those skilled in the art will recognize that changes may be made without departing from the scope of the invention. It is intended that the detailed description be regarded as illustrative and that the appended claims including all the equivalents are intended to define the scope of the invention. While the present invention has been illustrated in the appended drawings and the foregoing description, such illustration is to be considered illustrative or exemplifying and not restrictive; the present invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

In the appended claims, the word “comprising” does not exclude other elements or steps, and the indefinite article ”a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.