WO2022200239A1

WO2022200239A1 - Air disinfection via solid state light sources arranged to emit violet and/or ultraviolet light

Info

Publication number: WO2022200239A1
Application number: PCT/EP2022/057263
Authority: WO
Inventors: Matthias Wendt; Peter Deixler
Original assignee: Signify Holding B.V.
Priority date: 2021-03-26
Filing date: 2022-03-21
Publication date: 2022-09-29

Abstract

:A ceiling fan (610) arranged to be suspended from a ceiling (600), comprising a shaft (613) arranged to extend perpendicular from the ceiling, a motor (614), and at least one fan blade (611) extending from the shaft, wherein the at least one fan blade is arranged to be rotated by the motor upon operation for generating a flow of air, wherein the ceiling fan further comprises a solid state light source (620) arranged on at least one outer portion of an upper part of the at least one fan blade arranged to face the ceiling, wherein the solid state light source is arranged to emit light (621) of violet light and/or ultraviolet, UV, light in a wavelength range from 100 to 420 nm, and wherein the solid state light source is arranged to emit the light towards the ceiling.

Description

Air disinfection via solid state light sources arranged to emit violet and/or ultraviolet light

FIELD OF THE INVENTION

The present invention generally relates to techniques for disinfection of air. More specifically, the present invention relates to air disinfection via solid state light sources arranged to emit violet and/or ultraviolet (UV) light.

BACKGROUND OF THE INVENTION

There is a general need to increase the efficiency of air disinfection in many indoor spaces such as e.g. hospitals, emergency rooms, waiting rooms, offices, restaurants, industries, bams, etc. Notably, the recent COVID-19 pandemic has emphasized the importance of clean indoor air.

Prior art teaches that there are substantially three different transmission paths of pathogens such as COVID-19, namely the so called “fomite” path, the “large droplet” path (or “ballistic droplet” path) and the “aerosol” path. By the “fomite” path, a surface that contains a virus, such as a light switch, a door handle, or someone else’s hand, can transfer the virus onto a person’s hand, and the person may thereafter infect himself/herself by touching e.g. his/her mouth, nostrils, eyes, etc. The “large droplet” path or “ballistic droplet” path means that droplets of saliva or respiratory fluid (larger than approximately 100 pm) may be expelled from infected individuals when coughing, sneezing, and, to a lesser extent, talking. The droplets fly ballistically (like projectiles) through the air and may infect a person by impacting on the person’s mouth, nostrils and/or eyes. Droplets which do not impact may fall to the ground in 1-2 m. The “aerosol” path describes the case of aerosols, which are also particles of saliva or respiratory fluid, but of smaller size (smaller than approximately 100 pm). For this reason, aerosols can linger more in the air, from tens of seconds to hours, and can travel relatively long distances. Aerosols infect by being inhaled through a person’s nose or mouth, or (less likely) by deposition on the eyes. The linger time and/or the travel distance of the aerosols depend on their size, and they also reach different parts of the human respiratory tract.

In order to reduce the risk of pathogen infection in a room or space, the prior art discloses upper-air disinfection systems, i.e. disinfection systems arranged in the vicinity of a ceiling or relatively high up on a wall in a space or room. Such disinfection systems are mostly addressing upper air disinfection by means of wall-mounted or ceiling-mounted germicidal ultra-violet (UV) devices. For these prior art upper air systems, all wavelengths of UV, including also frequencies not safe for humans for prolonged eye/skin exposure, can be applied as the UV is contained in that upper room volume and will not reach room/space occupants. Any stray light into the lower air space due to reflection needs to be strongly managed. Upper air purification systems also treat pathogens in the whole room due to air movement.

The prior art teaches that proper designed upper-air ultra-violet germicidal irradiation (UVGI) systems deliver sufficient UVC radiation to inactivate a wide array of pathogens in the disinfection zone. It is well established that vertical air mixing is important for the efficiency of upper-air disinfection systems of this kind. An insufficient mixing can occur in rooms where the circulation is driven only by buoyancy due to heat sources in the room, wherein the mechanical system supplies limited volumes of air and/or wherein the air distribution of the mechanical system is not designed to provide a well-mixed space. Ideally, the mixing effectiveness of the mechanical ventilation/HVAC system should be measured in the room/space. However, measurement methods of this kind can be relatively costly.

It has been empirically found that a HVAC system present in the space/room may be ill suited for pairing to the upper-air UVGI. For instance, stratified air distribution systems typically mix the air between upper air and lower air satisfactory in cooling mode, but are not typically paired with upper air UVGI systems due to their lack of sufficient air mixing between the upper and lower room that is necessary for these types of systems to function from an occupant thermal comfort standpoint.

US2009/129974A1 discloses a ceiling paddle fan fixture for improving the quality of the air in the room and various methods of enhancing room air quality, with particular application in public spaces such as hospitals, health care institutions, dormitories, schools and offices. A UV-C source and an air mover are combined in a single fixture which uses a low intensity UV-C source and a paddle ceiling fan to significantly increase the mixing of the treated with the untreated room air. Sterilization of room air is achieved by the passage of a high volume of air at a relatively slow speed through a relatively low intensity UV-C field.

Hence, it is desired to provide alternative arrangements for disinfection of air which furthermore may meet demands of air mixing and comfort whilst being (cost) efficient. SUMMARY OF THE INVENTION

It is an object of the present invention to provide an arrangement or device for disinfection of air which may meet demands of air mixing and comfort whilst being (cost) efficient.

This and other objects are achieved by providing a ceiling fan having the features in the independent claim. Preferred embodiments are defined in the dependent claims.

Hence, according to a first aspect of the present invention, there is provided a ceiling fan arranged to be suspended from a ceiling. The ceiling fan comprises, at least, a shaft arranged to extend perpendicular from the ceiling, a motor, and at least one fan blade extending from the shaft and arranged to extend in a plane parallel to the ceiling. The at least one fan blade is arranged to be rotated by the motor upon operation for generating a flow of air. The ceiling fan further comprises at least one first solid state light source arranged on at least one outer portion of an upper part of the at least one fan blade arranged to face the ceiling. The at least one solid state light source is arranged to emit light of at least one of violet light and ultraviolet, UV, light in a wavelength range from 100 to 420 nm, and wherein the at least one solid state light source is arranged to emit the light towards the ceiling.

Thus, the present invention is based on the idea of providing an efficient upper air disinfection in a professional and/or residential room or space by the germicidal effect of violet and/or UV light emission, wherein the first state light sources are arranged on one or more outer portions of an upper part of the fan blades of a ceiling fan.

The present invention is advantageous in that the direction of the violet and/or UV light emission from the first solid state light source(s) of the ceiling fan is optimized for achieving an upper air disinfection effect while minimizing the stray (UV) light into the lower air volume of the room or space.

The ceiling fan comprising the first state light sources is advantageous in that ceiling fans often are perfectly placed or positioned to host a system or arrangement for (ultra) violet light disinfection. Hence, as ceiling fans often are positioned in the upper portion of a room or space, it is convenient and efficient that they are combined with an air disinfection function as provided by the present invention.

The present invention is further advantageous in that ceiling fans are often already installed in professional and/or residential places (in particular in countries having a warm climate), as well as in industries and/or agricultural facilities (e.g. bams). Therefore, the present invention is very convenient and (cost) efficient as the first state light sources may be arranged on the ceiling fan blade(s) in a retrofitting matter. It should be noted that the present invention is particularly advantageous with respect to ceiling fans in forms of industrial ventilation fans that have relatively large blades in order to move large volumes of air in(to) a bam or factory. Furthermore, the provision of UV disinfection light by the present invention may be highly desired in bams and/or stables to limit transmission of viruses between animals and/or from humans to animals and/or animals to humans.

The present invention is further advantageous in that the power supply to the first state light sources is versatile, in that the power supply to the first state light sources may be provided by the mains voltage to the ceiling fan or by power scavenging from the rotational energy of the ceiling fan.

The present invention is further advantageous in that the benefits of air circulation by the rotating fan blade(s) of the ceiling fan may be conveniently combined with the air disinfection properties of the light emitted by the first state light sources during operation.

A ceiling fan arranged to be suspended from a ceiling is provided. The ceiling fan comprises, at least, a shaft arranged to extend perpendicular from the ceiling, a motor, and at least one fan blade extending from the shaft. It will be appreciated that the fan blade(s) may extend perpendicular to the shaft, such that the fan blade(s) are arranged to extend in a plane parallel to the ceiling. Alternatively, the fan blade(s) may extend non-perpendicularly from the shaft. The ceiling fan may comprise an arbitrary number of fan blades, for example, two, three of four fan blades. The at least one fan blade is arranged to be rotated by the motor upon operation for generating a flow of air. Hence, in case of the fan blade(s) extending perpendicular to the shaft, the fan blade(s) is (are) arranged to rotate in a plane parallel to the ceiling. The ceiling fan further comprises at least one first solid state light source. By the term “solid state light source” (SSL source), it is here meant a light source which uses one or more semiconductor diodes. For example, the first state light source may comprise light- emitting diodes, LEDs, organic light-emitting diodes, OLEDs, polymer light-emitting diodes, PLEDs, laser diodes, superluminescent diodes, etc., as sources of illumination. The at least one solid state light source is arranged on at least one outer portion of an upper part of the at least one fan blade arranged to face the ceiling. In other words, the fan blade(s) comprise(s) an upper part which, at least partially, is parallel to the ceiling, and solid state light source(s) is (are) arranged on (an) outer portion(s) of this upper part. The at least one solid state light source is arranged to emit light of at least one of violet light and ultraviolet, UV, light in a wavelength range from 100 to 420 nm. For example, the at least one solid state light source may be configured to output UV light of one or more of the Ultra Deep UV range of 100 to 190 nm, the Deep UV light range of 190 to 220 nm, the UV-C range of 220 to 280 nm, the UV-B range of 280 to 315 nm and/or the UV-A light of 315 to 400 nm. In case the at least one solid state light source is a narrowband UV light source, it may be configured output UV light with a narrow wavelength distribution around e.g. 254 nm or 255 nm. Hence, the first state light source(s) is (are) arranged to emit violet light and/or UV light in a wavelength range from 100 to 420 nm. The at least one solid state light source is arranged to emit the light towards the ceiling. Hence, the first state light source(s) which is (are) arranged on one or more outer portions of the upper part of the fan blade(s) arranged to face the ceiling are arranged or configured to emit its violet and/or UV light towards the ceiling.

According to an embodiment of the present invention, the ceiling fan may further comprise at least one foil on which the at least one first solid state light source is arranged, wherein the at least one foil is arranged to be fastened to the at least one outer portion of the at least one fan blade. By the term “foil”, it is here meant a (carrier) foil, lamination, or the like. Hence, the foil(s) on which the one or more first solid state light sources are arranged may be fastened to the outer portion(s) of the fan blade(s), e.g. by (manual) lamination. The present embodiment is advantageous in that the retrofitting of the first solid state light sources on (existing) ceiling fans may be achieved even more efficiently and conveniently. The present embodiment is advantageous in that the foil with the first solid state light sources arranged thereon may be relatively thin, thereby not (at least substantially) interfering with the air-circulation properties of the fan blade(s) of the ceiling fan.

According to an embodiment of the present invention, the at least one first solid state light source may be integrated on the at least one outer portion of the at least one fan blade. The present embodiment is advantageous e.g. in case of a replacement of the fan blade(s) due to e.g. a malfunctioning and/or damage of the fan blade(s) and/or first solid state light source(s).

According to an embodiment of the present invention, the ceiling fan may comprise an electric generator coupled to the at least one solid state light source, the electric generator comprising a circular-shaped stator comprising at least one magnet, and at least one rotor unit comprising at least one coil, wherein the at least one rotor unit is arranged on the at least one fan blade and in close proximity to the perimeter of the stator, whereby upon operation of the ceiling fan and rotation of the at least one fan blade, the generator is arranged to generate electric power to the at least one first solid state light source via the resulting rotation of the at least one rotor unit with respect to the stator. Hence, the ceiling fan may supply the first solid state light source(s) with electric power scavenged from the rotation of the fan blade(s) with respect to the ceiling fan. The present embodiment is advantageous in that the first solid state light source(s) may be operated without batteries and/or power from the ceiling fan’s mains voltage, which may lead to an even more convenient arrangement of power supply to the first solid state light source(s).

According to an embodiment of the present invention, the at least one fan blade may be warped such that a normal of a first outer portion of the at least one outer portion of the at least one fan blade is different from a normal of a second outer portion of the at least one portion of the at least one fan blade, and wherein a density of the number of the at least one first solid state light source per unit area of a respective outer portion of the at least one fan blade is dependent on a direction of the normal of the respective outer portion. By the term “warped”, it is here meant twisted around the elongated axis (of the fan blade). The present embodiment is advantageous in that the light emitted by the first solid state light sources for air disinfection may be customized. For example, one or more portions of the fan blade(s) being parallel, or substantially parallel, with the ceiling may have a relatively high density of concentration of first solid state light sources per unit area, wherein these first solid state light sources are arranged to disinfect a relatively high portion of the upper air close to the ceiling of the room or space. Analogously, one or more portions of the fan blade(s) having normal pointing obliquely towards the ceiling, may have a relatively low density of concentration of first solid state light sources per unit area, wherein these first solid state light sources are arranged to disinfect a relatively low portion of the upper air of the room or space.

According to an embodiment of the present invention, the ceiling fan may further comprise at least one first sensor arranged on the at least one outer portion of the at least one fan blade, wherein the at least one first sensor is screened from direct impingement of the light emitted from the at least one first solid state light source and configured to sense the light emitted from the at least one first solid state light source as reflected. In other words, the first sensor(s) is (are) configured to sense the violet and/or the UV light as reflected by the ceiling and/or wall(s) of the room or space, whilst being screened (i.e. shielded and/or protected) from direct impingement of the light emitted from the first solid state light source(s). The present embodiment is advantageous in that the first sensor(s) may sense or register that the amount of reflected violet light and/or UV light exceeds a threshold (limit) value, and one or more actions may be taken as a result hereof. For example, the ceiling fan may be configured to send an alarm to persons present in the room or space of the exceeding of their threshold/limit. Additionally, or independently of the alarm, the ceiling fan may be configured to a reduce the intensity of the violet and/or UV light.

According to an embodiment of the present invention, at least one property of the at least one first solid state light source is set as a function of at least one dimensional property of the ceiling fan. In other words, one or more properties of the first solid state light source(s) may be set or determined as a function (based on) one or more dimensions of the ceiling fan. For example, the intensity of the violet and/or UV light emitted by the first solid state light sources may be set dependently on the installation metrics (e.g. fan blade height with respect to the ceiling, fan blade rotation speed, etc.). The present embodiment is advantageous in that the disinfection properties of the ceiling fan with respect to the safety properties of the ceiling fan may be balanced/optimized.

According to an embodiment of the present invention, the at least one first solid state light source may comprise at least one light-emitting diode, LED. The present embodiment is advantageous in that LEDs provide numerous advantages compared to incandescent lamps, fluorescent lamps, neon tube lamps, etc., such as a longer operational life, a reduced power consumption, and an increased efficiency related to the ratio between light energy and heat energy.

According to an embodiment of the present invention, the ceiling fan may further comprise at least one second solid state light source arranged on at least one outer portion of a lower part of the at least one fan blade arranged to face a floor. The present embodiment is advantageous in that an upper air disinfection as well as a lower air disinfection is achieved in a very cost-efficient way.

According to an example of the present invention, the ceiling fan may be configured to operate the at least one first solid state light source as a function of the rotation of the at least one fan blade. For example, the operation of the at least one first solid state light source and the rotation of the fan blade(s) may be interlocked in order to ensure simultaneous operation. The ceiling fan may for example utilize an accelerometer or a rotation activity signal for this purpose. According to another example, the operation of the at least one first solid state light source may be regulated depending on the speed of the fan blade(s). It will be appreciated that the pathogen deactivation efficacy of the UV light depends on the integral administered dose of UV. A first volume of air directly above the first solid state light sources on the fan blades receives a higher UV dose than a second volume of air further away. As for faster fan blade speeds, the air relatively close to the fan blades is subjected for a shorter period by UV light before it is blown further away by the fan blades. Hence, it is advantageous for the ceiling fan to determine the current fan speed (e.g. via accelerometer or alternatively by counting magnets per minute for the energy-scavenging embodiment proposed) and adjust the UV intensity of the first solid state light sources based thereupon. Furthermore, one or more sensors of the ceiling fan may allow determining space occupancy and or air quality to influence the intensity and/or timing of the first solid state light sources.

According to an example of the present invention, the ceiling fan may be configured to initiate a rotation of the at least one fan blade at a first time point, ti, and to initiate an operation of the at least one first solid state light source at a second time point, t2, subsequent to the first time point, ti. Hence, according to this example, ceiling fan may be configured to operate the first solid state light sources after a waiting time or time interval after the initiated operation of the fan blade(s). In this way, the ceiling fan may, for example, blow away dust and thereby increase effectiveness of the disinfection provided by the ceiling fan via the first solid state light sources. Alternatively, or in combination herewith, the ceiling fan may also deactivate the operation of the first solid state light source after a predetermined time in order to reduce power consumption, preserve battery life and/or increase lifetime of the first solid state light sources.

According to an example of the present invention, the ceiling fan may further comprise at least one infrared, IR, light source. For example, the IR light source(s) may be used to dry surfaces in humid areas and/or to produce a natural warmth from above.

According to an example of the present invention, the at least one fan blade may extend from the shaft by an angle, a, and the ceiling fan may be configured to operate the at least one solid state light source as a function of the angle, a. For example, the fan blade(s) may extend perpendicularly from the shaft, i.e. by an angle a=90°, or alternatively, the fan blade(s) may extend from the shaft by an angle, a, in the interval 90°<a<135°, and the ceiling fan may be configured to operate the first solid state light source(s) accordingly.

According to an embodiment of the present invention, there is provided a ceiling fan system. The ceiling fan system may comprise a ceiling fan according to any one of the preceding embodiments and a control unit coupled to at least one of the motor and the at least one first solid state light source. The control unit is configured to control at least one of an operation of the at least one fan blade via the motor and an operation of the at least one first solid state light source. Hence, the control unit is coupled to the motor and/or the first solid state light source(s) and configured to control the fan blade operation via the motor and/or the operation of the first solid state light source(s). The present embodiment is advantageous in that the operation of the disinfection functionality of the ceiling fan via the first solid state light sources and the air mixing functionality of the ceiling fan may be customized/ optimized.

According to an embodiment of the present invention, the control unit may be configured to control the operation of the at least one fan blade via the motor and to control the operation of the at least one first solid state light source as a function of a rotation rate of the at least one fan blade. For example, the control unit may be configured to increase the intensity of the violet light and/or the UV light of the first solid state light source(s) upon an increase of the fan blade speed which improves the disinfection functionality of the ceiling fan system as well as the level of disinfection in a room. In addition, the level of safety of the disinfection may be improved.

According to an embodiment of the present invention, the control unit may be configured to control a direction of rotation of the at least one fan blade and to control the operation of the at least one first solid state light source as a function of the direction of rotation of the at least one fan blade. It should be noted that the control unit may be configured to operate the fan blade(s) in different directions e.g. dependent on the climate and/or season (winter/summer), and the control unit may control the operation of the first solid state light source(s) accordingly. The present embodiment is advantageous in that the operation of the disinfection functionality of the ceiling fan via the first solid state light sources and the air mixing functionality of the ceiling fan may be conveniently adapted by the control unit. Hence, the disinfection functionality of the ceiling fan system is improved.

In addition, the level of safety of the disinfection may be improved.

According to an embodiment of the present invention, the control unit may be configured to control the operation of the at least one first solid state light source as a function of an ambient temperature. It will be appreciated that when temperatures in a space are relatively high, occupants will very likely run the ceiling fan at higher speeds to increase occupant thermal comfort. Analogously, when temperatures in a space are relatively low, occupants are less likely to operate the ceiling fan at high speed to avoid draft (unwanted cooling). Dependent on the ambient (i.e. room) temperature, the control unit may efficiently and conveniently control the operation of the first solid state light source(s).

According to an embodiment of the present invention, the ceiling fan may comprise at least one second sensor arranged to register at least one information, wherein the at least one second sensor is communicatively coupled to the control unit and configured to send the at least one information to the control unit. The control unit is configured to control at least one of the operation of the at least one fan blade via the motor and the operation of the at least one first solid state light source, based on the at least one information received from the at least one second sensor. By the term “information”, it is here meant substantially any kind of information or data such as e.g. occupancy and/or temperature in the room or space, etc. Hence, the ceiling fan may obtain information via the second sensor(s) and transmit the information to the control unit, which in turn may control the fan blade operation and/or the operation of the first solid state light source(s) based on this information. The present embodiment is advantageous in that an even further improved operation of the ceiling fan with respect to air disinfection and/or air mixing is provided. Hence, the disinfection functionality of the ceiling fan system is improved. In addition, the level of disinfection in a room may be improved. In addition, the level of safety of the disinfection may be improved.

According to an embodiment of the present invention, the control unit may be arranged physically separate from the ceiling fan, and wherein the control unit is communicatively coupled to the ceiling fan. For example, the control unit may be operated by a user. The present embodiment is advantageous in that the versatility of the control of the ceiling fan is increased.

Further objectives of, features of, and advantages with, the present invention will become apparent when studying the following detailed disclosure, the drawings and the appended claims. Those skilled in the art will realize that different features of the present invention can be combined to create embodiments other than those described in the following.

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 embodiment(s) of the invention.

Fig. 1 schematically shows a ceiling fan according to an exemplifying embodiment of the present invention,

Figs. 2 and 3 schematically show portions of a ceiling fan according to exemplifying embodiments of the present invention,

Fig. 4 schematically shows a portion of a fan blade of a ceiling fan according to an exemplifying embodiment of the present invention, and

Fig. 5 schematically shows a ceiling fan system according to an exemplifying embodiment of the present invention. DETAILED DESCRIPTION

Fig. 1 schematically shows a ceiling fan 610 according to an exemplifying embodiment of the present invention. The ceiling fan 610 is arranged to be suspended from a ceiling 600 in substantially any residential, professional and/or industrial room or space, such as an emergency room, a waiting room, an office, a restaurant, an industry plant space, a farm bam, etc. The ceiling fan 610 comprises a shaft 613 arranged to extend perpendicular from the ceiling 600. The ceiling fan 610 further comprises a motor 614 arranged at the lower end portion of the shaft 613. The ceiling fan 610 further comprises two fan blades 611 extending from the shaft 613. In this example, the fan blades 611 extend perpendicular to the shaft 613 and extend in a plane parallel to the ceiling 600, i.e. the fan blades 611 extend from the shaft 613 by an angle, a=90°. Alternatively, the fan blades 611 may extend non-perpendicularly from the shaft 613, i.e. at an angle ¹ 90° from the shaft 613. For example, the fan blades 611 may extend from the shaft 613 by an angle, a, which is larger than 90°, e.g. that the angle, a, is in the interval 90°<a<135°. The fan blades 611 are arranged to be rotated by the motor 614 upon operation for generating a flow of air. Hence, in case of the fan blades 611 extending perpendicular to the shaft 613, the fan blades 611 are arranged to rotate in a plane parallel to the ceiling 600. The fan blades 611 are generally warped (e.g. like a propeller) in order to generate the flow of air. The ceiling fan 610 further comprises a plurality of first solid state light sources 620, such as LEDs, organic light-emitting diodes, OLEDs, polymer light- emitting diodes, PLEDs, laser diodes, superluminescent diodes, etc. The first solid state light sources 620 are arranged on one or more outer portions of an upper part of the fan blades 611 arranged to face the ceiling 600. The first solid state light sources 620 may be arranged in series or in parallel with respect to the elongation of the fan blades 611. The first solid state light sources 620 are arranged to emit light 621 of violet light and/or UV light in a wavelength range from 100 to 420 nm such as e.g. 100 to 190 nm (Ultra Deep UV range),

190 to 220 nm (Deep UV light range), 220 to 280 nm (UV-C range), 280 to 315 nm (UV-B range) and/or 315 to 400 nm (UV-A light). The first solid state light sources 620 may be arranged to emit light 621 of violet light and/or UV light with wavelengths such as 222 nm (so called far-UV(C)). Hence, the first solid state light sources 620 may comprise or constitute 222 nm far-UV(C) light sources for the upper air purification of the ceiling fan 610. It is known that stray UV light from the area in the vicinity of the ceiling can lead to UV exposure in lower parts of the room or space, wherein the UV exposure may be above the threshold limit values of eye and/or skink safety. However, it should be noted that stray light from 222 nm far-UV(C) light sources generally has less safety issues. In Fig. 1, the first solid state light sources 620 are arranged to emit the light 621 towards the ceiling 600. The ceiling fan 610 may further comprise one or more second solid state light sources (not shown) arranged on at least one outer portion of a lower part of the fan blade 611 arranged to face a floor, i.e. oppositely arranged the first solid state light sources 620. It should be noted that the ceiling 600 and/or the ceiling fan 610 may comprise a non-UV-reflecting die as a precaution for avoiding reflections of the light 621 into the room below the ceiling 600.

Fig. 2 schematically shows a portion of a ceiling fan 610 according to an exemplifying embodiment of the present invention. It will be appreciated that the ceiling fan 610 in Fig. 2 corresponds to the ceiling fan 610 as exemplified in Fig. 1 and the associated text, and it is referred to this figure and/or text for an increased understanding of the feature and/or the functioning of the ceiling fan 610. In Fig. 2, the ceiling fan 610 comprises a foil 630 (e.g. a lamination) on which the plurality of first solid state light sources 620 are arranged, wherein the first solid state light sources 620 are configured to emit light 621 of violet light and/or UV light. The foil 630 is arranged to be fastened to the outer portion of the upper part of the fan blades 611 arranged to face the ceiling. Alternatively, the first solid state light sources 620 may be integrated on the outer portion of the fan blades 611.

Fig. 3 schematically shows a portion of a ceiling fan 610 according to an exemplifying embodiment of the present invention. It will be appreciated that the ceiling fan 610 in Fig. 3 corresponds to the ceiling fan 610 as exemplified in Fig. 1 and the associated text, and it is referred to this figure and/or text for an increased understanding of the feature and/or the functioning of the ceiling fan 610. In Fig. 3, the ceiling fan 610 comprises an electric generator for supplying the first solid state light sources 620, which are configured to emit light 621 of violet light and/or UV light, with electric power scavenged from the rotation of the fan blades 611 with respect to the ceiling fan 610. The electric generator, which is coupled to the first solid state light sources 620, comprises a ring-shaped stator 640 comprising a plurality of magnets 642. The stator 640 is fastened to the shaft 613 by a holder 641. The electric generator further comprises a rotor unit 651 comprising at least one coil 650. The rotor unit 651 is arranged on the respective fan blade 611 and is arranged in close proximity to the perimeter of the stator 640, such that upon operation of the ceiling fan 610 and rotation of the fan blades 611, the generator is arranged to generate electric power to first solid state light sources 620 via the resulting rotation of the rotor unit 651 with respect to the stator 640. The stator 640, in the exemplified form of a magnet ring, is causing a change of electric field directions when the coil(s) 650 is (are) put in motion due to operation of the fan blades 611. According to an example, the first solid state light sources 620 may flash at every electromagnetic field change. It should be noted that in case a relatively small number of flux changes are generated over one revolution of the fan blades 611, the flashing may possibly not be sufficient for a satisfactory disinfection of the air. In such a case, the electric generator of the ceiling fan 610 may comprise a local energy storage, such as a Li-ion battery, an electrolytic capacitor or a gold capacitor, for storing the energy generated upon rotation of the fan blades 611. Consequently, the local energy storage may supply the first solid state light source 620 with energy for a (more) continuous light emission, thereby achieving a desired disinfection of the air by the ceiling fan 610. In the case as exemplified in Fig. 3, the stator 640 and coil(s) 650 are directed vertically to make the general function better visible. Alternatively, the coil(s) 650 may be mounted horizontally on the fan blades 611 and be laminated. In this latter case, the stator 640 has to generate a vertical field in order to induce flux changes in the plane of the fan blades 611. It will be appreciated that many alternative ways to construct the latter embodiment are possible. For example, the coil(s) 650 may be integrated in a flexible sticky foil which, as an example, may extend near to the shaft 613. In that case the magnet assembly as described may be arranged directly above the motor housing on the shaft 613. Alternatively, other energy scavenging techniques can be applied in the ceiling fan 610 like photovoltaic cells, thermo generators and/or generators which are configured to generate electric power from the vibrations in the fan blades 611 due to air turbulences. As yet another example, the ceiling fan 610 may comprise a windmill arrangement for generating the required energy for the first state light sources 620.

Fig. 4 schematically shows a portion of a fan blade 611 of a ceiling fan 610 according to an exemplifying embodiment of the present invention. The fan blade 611 is warped such that a normal of a first outer portion 680 of the fan blade 611 is different from a normal of a second outer portion 682 of the fan blade 611. A density (concentration) of the number of the first solid state light sources 620 per unit area of a respective outer portion 680, 682 of the fan blade 611 is dependent on a direction of the normal of the respective outer portion 680, 682. According to the example of Fig. 4, the first outer portion 680 of the fan blade 611 is parallel, or substantially parallel, with the ceiling, and has a relatively high density of concentration of first solid state light sources 620 per unit area, wherein these first solid state light sources 620 are arranged to disinfect a relatively high portion of the upper air close to the ceiling of the room or space. Analogously, the second outer portion 682 of the fan blade 611 having a normal pointing obliquely towards the ceiling, has a relatively low density of concentration of first solid state light sources 620 per unit area, and these first solid state light sources 620 are arranged to disinfect a relatively low portion of the upper air of the room or space.

Fig. 5 schematically shows a ceiling fan system 100 according to an exemplifying embodiment of the present invention. The ceiling fan system 100 comprises a ceiling fan 610 according to any one of the preceding examples as described. The ceiling fan 610 further comprises a control unit 110. Here, it is exemplified that the control unit 110 is arranged in a holder 612 of the ceiling fan 610, but it should be noted that the control unit 110 may be placed substantially anywhere in the ceiling fan 610. Alternatively, the control unit 110 may be arranged remotely from, i.e. at a distance from, the ceiling fan 610. In this example of the control unit 110 being arranged physically separate from the ceiling fan 610, the control unit 110 may be communicatively coupled to the ceiling fan 610 via any kind of wired or wireless communication arrangement. In Fig. 5, the control unit 110 is coupled to the motor 614 and/or the first solid state light sources 620. The control unit 110 is configured to control an operation of the fan blades 611 via the motor 614 and/or an operation of the first solid state light sources 620. The control unit 110 may be configured to control the operation of the fan blades 611 via the motor 614 and to control the operation of the first solid state light sources 620 as a function of a rotation rate of the fan blades 611. For example, the control unit 110 may be configured to increase the intensity of the violet light and/or the UV light 621 of the first solid state light sources 620 upon an increase of the fan blade 611 speed. According to another example, the control unit 110 may be configured to control a direction of rotation of the fan blades 611 and to control the operation of the first solid state light sources 620 as a function of the direction of rotation of the fan blades 611. Furthermore, the control unit 110 may be configured to control the operation of the first solid state light sources 620 as a function of an ambient temperature. For example, the control unit 110 may be configured to operate the fan blades 611 at higher speeds when temperatures in a space are relatively high. Analogously, when temperatures in a space are relatively low, the control unit 110 may be configured to operate the fan blades 611 at lower speeds. According to yet another example, a ceiling fan 610 in form of a ventilation fan in a bam may typically rotate at a speed/rate of 30 rpm to maintain a basic air flow and may increase to 500 rpm when the bam needs cooling. Hence, the control unit 100 may be configured to operate a ceiling fan 610 of this kind throughout a day as a function of external temperature and/or the amount of sunshine impinging on the bam.

Optionally, and as exemplified in Fig. 5, the ceiling fan 610 may further comprise a first sensor 115 arranged on the outer portion of the fan blade 611. The first sensor 115 is screened from direct impingement of the light 621 emitted from the first solid state light sources 620. The first sensor 115 is configured to sense the light emitted from the first solid state light sources 620 as reflected. In other words, the first sensor 115 is configured to sense the violet and/or the UV light as reflected by the ceiling and/or wall(s) of the room or space, whilst being screened (i.e. shielded and/or protected) from direct impingement of the light emitted from the first solid state light sources 620. According to the example in Fig. 5, the ceiling fan 610 optionally comprises a second sensor 120 arranged to register at least one information such as occupancy and/or temperature in the room or space, etc. The first and/or second sensors 115, 120 is (are) communicatively coupled to the control unit 110 and configured to send information to the control unit 110. The control unit 110 is configured to control the operation of the fan blades 611 via the motor 614 and/or the operation of the first solid state light sources 620, based on the information received from the first and/or second sensor 120. Here, it is exemplified that the second sensor 120 is arranged on the holder 612 of the ceiling fan 610, but it should be noted that the second sensor 120 may be placed substantially anywhere on the ceiling fan 610. Alternatively, the second sensor 120 may be arranged remotely from, i.e. at a distance from, the ceiling fan 610. In this example of the second sensor 120 being arranged physically separate from the ceiling fan 610, the second sensor 120 may be communicatively coupled to the control unit 110 via any kind of wired or wireless communication arrangement. The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the size, number, positioning, etc., of the fan blade(s) 611, the first solid state light source(s) 620, etc., may be different than that shown.

Claims

CLAIMS:

1. A ceiling fan system (100), comprising: a ceiling fan (610) arranged to be suspended from a ceiling (600), the ceiling fan at least comprising a shaft (613) arranged to extend perpendicular from the ceiling, a motor, and at least one fan blade (611) extending from the shaft, wherein the at least one fan blade is arranged to be rotated by the motor upon operation for generating a flow of air, wherein the ceiling fan further comprises: at least one first solid state light source (620) arranged on at least one outer portion of an upper part of the at least one fan blade arranged to face the ceiling, wherein the at least one first solid state light source is arranged to emit light (621) of at least one of violet light and ultraviolet, UV, light in a wavelength range from 100 to 420 nm, and wherein the at least one first solid state light source is arranged to emit the light towards the ceiling, the ceiling fan system (100) further comprising: a control unit (110) coupled to at least one of the motor and the at least one first solid state light source (620), wherein the control unit (110) is configured to control at least one of an operation of the at least one fan blade (611) via the motor and an operation of the at least one first solid state light source (620), wherein the control unit is configured to:

(i) control the operation of the at least one fan blade via the motor and to control the operation of the at least one first solid state light source as a function of a rotation rate of the at least one fan blade, and/or,

(ii) to control a direction of rotation of the at least one fan blade and to control the operation of the at least one first solid state light source as a function of the direction of rotation of the at least one fan blade, and/or

(iii) to control at least one of the operation of the at least one fan blade via the motor and the operation of the at least one first solid state light source, based on at least one information received from at least one second sensor, wherein the ceiling fan comprises the at least one second sensor (120) arranged to register the at least one information, wherein the at least one second sensor is communicatively coupled to the control unit and configured to send the at least one information to the control unit (110).

2. The ceiling fan system (100) according to claim 1, further comprising at least one foil (630) on which the at least one first solid state light source is arranged, wherein the at least one foil is arranged to be fastened to the at least one outer portion of the at least one fan blade.

3. The ceiling fan system (100) according to claim 1, wherein the at least one first solid state light source is integrated on the at least one outer portion of the at least one fan blade.

4. The ceiling fan system (100) according to any one of the preceding claims, further comprising an electric generator coupled to the at least one first solid state light source, the electric generator comprising a circular-shaped stator (640) comprising at least one magnet (642), and at least one rotor unit (650) comprising at least one coil, wherein the at least one rotor unit is arranged on the at least one fan blade and in close proximity to the perimeter of the stator, whereby upon operation of the ceiling fan and rotation of the at least one fan blade, the generator is arranged to generate electric power to the at least one first solid state light source via the resulting rotation of the at least one rotor unit with respect to the stator.

5. The ceiling fan system (100) according to any one of the preceding claims, wherein the at least one fan blade is warped such that a normal of a first outer portion of the at least one outer portion of the at least one fan blade is different from a normal of a second outer portion of the at least one portion of the at least one fan blade, and wherein a density of the number of the at least one first solid state light source per unit area of a respective outer portion of the at least one fan blade is dependent on a direction of the normal of the respective outer portion.

6. The ceiling fan system (100) according to any one of the preceding claims, further comprising at least one first sensor (115) arranged on the at least one outer portion of the at least one fan blade, wherein the at least one first sensor is screened from direct impingement of the light emitted from the at least one first solid state light source and configured to sense the light emitted from the at least one first solid state light source as reflected.

7. The ceiling fan system (100) according to any one of the preceding claims, wherein at least one property of the at least one first solid state light source is set as a function of at least one dimensional property of the ceiling fan.

8. The ceiling fan system (100) according to any one of the preceding claims, wherein the at least one first solid state light source comprises at least one light-emitting diode, LED.

9. The ceiling fan system (100) according to any one of the preceding claims, further comprising at least one second solid state light source arranged on at least one outer portion of a lower part of the at least one fan blade arranged to face a floor.

10. The ceiling fan system (100) according to any one of the preceding claims, wherein the ceiling fan comprises the controller.

11. The ceiling fan system (100) according to any one of the preceding claims, wherein the at least one solid state light source is configured to output UV light of one or more of the Ultra Deep UV range of 100 to 190 nm, the Deep UV light range of 190 to 220 nm, the UV-C range of 220 to 280 nm, the UV-B range of 280 to 315 nm and/or the UV-A light of 315 to 400 nm..

12. The ceiling fan system (100) according to any one of the preceding claims, wherein the at least one first solid state light source is arranged to emit light (621) of both violet light and ultraviolet, UV, light in a wavelength range from 100 to 420 nm.

13. The ceiling fan system (100) according to any one of the preceding claims, wherein the control unit is configured to control the operation of the at least one first solid state light source as a function of an ambient temperature.

14. The ceiling fan system (100) according to any one of preceding claims, wherein the control unit is arranged physically separate from the ceiling fan, and wherein the control unit is communicatively coupled to the ceiling fan.