Illumination device using microwave radiation

Abstract

The present invention relates to an illumination device comprising a microwave generator for generating microwaves into a volume, the microwaves for sterilizing the volume, a lighting load for emitting light for illuminating an external object, and a housing, the housing surrounding the volume and configured to prevent microwaves from passing through the housing and to allow light to pass through.

Description

Technical Field

[0001] The present invention relates to lighting devices. The present invention further relates to an array of lighting devices.

Background Art

[0002] Recent pathogen outbreaks have shown an increasing need for more powerful, efficient, fast, inexpensive, and accessible ways to combat infectious diseases. Pathogens such as viruses can infect through short - range particle transmission between humans, for example, when coughing or sneezing, but also have a high potential to infect through aerosols containing virus particles. Aerosols are generated by humans during normal human functions such as breathing and conversation. Aerosol droplets containing virus particles can remain in the air for a fairly long time, posing a danger to people present in the space. As a mitigation method, sterilization devices are often installed in air - circulation systems. These devices filter the air, inactivate the virus particles in the aerosol droplets, and then return the air to the space, thus sterilizing the air.

[0003] Recent sterilization methods mainly involve the introduction of UV - C (ultraviolet - C: deep ultraviolet) light - based sterilization systems based on conventional UV - C light tubes, excimer lamps, or xenon lamps. In such systems, air (and the aerosol droplets it contains) is treated by UV - C radiation. However, exposure to UV - C sterilization light beyond the threshold dose limit is very harmful to humans and can cause eye and / or skin damage. Therefore, even when UV - C light is hidden within an air - conditioning / circulation system, there is a risk of leakage, which can harm people's health. Even when such a system is designed with the most safety measures and the lowest risk of UV - C light leakage, it may still be perceived as dangerous by potential customers.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a lighting device that provides a safer means as an alternative to a UV-C sterilization system.

Means for Solving the Problems

[0005] To overcome this problem, in a first aspect of the present invention, a lighting device is provided. The lighting device includes a microwave generator for generating microwaves to a volume, the microwaves being for sterilizing the volume, a lighting load for emitting light for illuminating an external object, a housing, and the housing surrounds the volume and is configured to prevent microwaves from passing through the housing and to allow light to pass through.

[0006] The lighting device is used to generate microwaves and at least general illumination light. The microwaves are emitted to the volume. The volume will be disinfected by the microwaves. Since the volume is surrounded by a housing configured to prevent microwaves from passing through the housing, the microwaves are contained in the volume. The housing may be interpreted as a Faraday cage. Since the lighting device also has a lighting load for emitting light for illuminating an external object, the housing needs to be adapted to allow light to pass through. This may be done by providing the housing with at least one opening that allows light to pass through but prevents microwaves from exiting the volume.

[0007] In a further example, the housing has a plurality of openings, and each of the plurality of openings has an effective diameter smaller than 1 / 10 of the wavelength of the microwave.

[0008] By providing an opening in the housing, light can easily pass through the housing. When the effective diameter of the opening is smaller than 1 / 10 of the wavelength of the microwave, the microwave cannot escape from the housing, and the opening provides a surface large enough to optimally allow light to pass through the housing.

[0009] In a further example, the housing has a surface, and at least a part of the surface includes a coating for reflecting microwaves. The surface faces the microwave generator, and the microwave is reflected into the volume.

[0010] When the housing is provided with a coating for reflecting microwaves, the efficiency of generating microwaves in the lighting device can be improved. To prevent the microwave from passing through the housing, the housing may absorb the microwave. The absorption characteristics of the housing may depend on the thickness of the material. The thickness of the material can be various. For example, the lower material can be made thick to prevent the microwave from going downward, and the side material can be made thin to allow the microwave to escape and sterilize the air near the lamp without interacting with people. When at least a part of the microwave is reflected back into the volume, the microwave can be reused to sterilize the volume instead of being absorbed by the housing.

[0011] An example of a housing with a coating is a thin layer of metal that is transparent to visible light but reflects microwaves, for example, a gold layer with a thickness of nm. Another example is a closed transparent polymer or glass cover with a fine pattern of metal wires. Another example is a cover material made of a conductive polymer that is visible light transmissive and may also be conductive.

[0012] In a further example, the housing comprises a conductive material, and the conductive material is configured to prevent microwaves from passing through the housing.

[0013] When the housing comprises a conductive material, microwaves can be blocked most efficiently. Conductive materials are widely available and are easy to form into a desired housing. Further, the conductive material has very good microwave reflection capability, for example, by reflecting microwaves back into the volume.

[0014] In a further example, the conductive material is a metal.

[0015] In a further example, the microwave generator is adapted to generate microwaves having a frequency between 300 MHz and 300 GHz.

[0016] When microwaves are generated in the range of 300 MHz and 300 GHz, pathogens will be damaged or destroyed by microwaves having these wavelengths and thus can be used for disinfection.

[0017] In a further example, the microwave generator is adapted to be controllable independently of a light source.

[0018] It may be desirable to control the microwave generator independently of the light source. For example, when the light is off, it may be desirable to keep the microwave generator on, and vice versa.

[0019] In a further example, the lighting device an air entry and an air exit that respectively enable air to enter and exit the volume, An air flow generator for allowing air to flow from an air inlet to an air outlet, is included.

[0020] When an air flow generator, for example, a fan, is used to provide an air flow flowing through a volume, an air inlet and an air outlet may be desirable. This allows the air flow flowing through the volume to be regulated. The regulation of the air flow may be linked to the amount of disinfection required. Additionally, or alternatively, the regulation of the air flow may be linked to the amount of microwaves generated.

[0021] In a further example, the air inlet and the air outlet are arranged such that air flows over a light source so as to provide cooling of the lighting load.

[0022] In the case of an air flow where air flows over a light source, the air flow can provide active cooling of the light source, effectively cooling the light source and extending its lifespan.

[0023] In a further example, the housing includes a non-conductive transparent cover.

[0024] To prevent unwanted elements from entering the volume, the non-conductive transparent cover can be arranged inside or outside the housing. The housing prevents microwaves from exiting the volume, and the cover prevents other things from entering the volume. Preferably, in this case, dedicated air inlets and air outlets are provided.

[0025] In a further example, the microwave generator is adapted to generate microwaves having a frequency of 8.2 GHz.

[0026] The pathogens that need to be damaged or destroyed are most vulnerable to microwaves having a wavelength of 8.2 GHz. In this example, 8.2 GHz is the most effective frequency for destroying the influenza virus. The microwave generator may provide multiple microwaves at multiple frequencies so that multiple pathogens can be damaged or destroyed.

[0027] In a further example, air is supplied to the volume through the housing at a first location, and the apparatus further includes an ionizer coupled to the first location for ionizing the air entering the volume to a first potential, and the housing is adapted to be set to the first potential.

[0028] In addition to the microwave generator, an ionizer can be used. The ionizer generates ions in the air flow. These ions can damage or destroy at least a portion of the pathogens and / or the carrier molecules carrying the pathogens. Further, the particles in the air that may carry the pathogens are charged to the same potential as the housing, and thus, the occurrence of collisions between the particles and the housing is reduced.

[0029] In a further example, the lighting load includes a light emitting diode (LED).

[0030] Preferably, the LED is used as the lighting load. This is because the LED converts electrical energy into visible light very efficiently.

[0031] In a further example, the lighting device further includes a presence sensor for detecting the presence within the space, and when the presence is detected, the microwave generator is activated.

[0032] A presence sensor may be used to turn on a microwave generator when it detects a person entering a room. The room may be a dedicated location within a building, but it should also be understood that any type of environment or volume may also be defined as a room. It may be desirable to sterilize the air entering the volume only when a presence is detected. When no one is present in the room, the microwave generator may be turned off as sterilization may not be necessary. Alternatively, or additionally, a lighting load may also respond to the presence detection.

[0033] In another example, an array of lighting devices is provided. The array of lighting devices is arranged in a grid pattern.

[0034] When a plurality of lighting devices are used and arranged in a grid pattern, a larger volume of air is effectively sterilized.

Brief Description of the Drawings

[0035] Here, examples of the present invention will be described with reference to the accompanying drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0036] The present invention will be described with reference to the figures.

[0037] The detailed description and specific examples are illustrative of exemplary embodiments of the apparatus, system, and method, but are for illustrative purposes only and are not intended to limit the scope of the invention. It should be understood that these and other features, aspects, and advantages of the apparatus, system, and method of the present invention will be better understood from the following description, the appended claims, and the accompanying drawings. It should also be understood that the drawings are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the drawings to indicate the same or similar parts.

[0038] FIG. 1 shows an example of a lighting device. The lighting device has a microwave generator 1 used to generate microwave radiation. The lighting device also has a lighting load 2 that emits light for illuminating an external object. Therefore, the lighting device can be used for general lighting, such as illuminating at least a part of a room. The lighting device has a housing 3 that surrounds a volume 4. The housing 3 can be part of a lighting fixture that contains all components of the lighting fixture. In the example of the lighting fixture, this means that the housing 3 surrounds the microwave generator 1 and the lighting load 2. The microwave generator 1 and the lighting load 2 may be controlled by a control unit 7. The control unit 7 may also be surrounded by the housing 3. The control unit 7 may control the power supplied to the microwave generator 1 and the lighting load 2. The control unit 7 may perform independent power control to the microwave generator 1 and the lighting load 2 so that the microwave generator 1 and the lighting load 2 can be controlled independently of each other. A major advantage of arranging the microwave generator 1 in the lighting device with the lighting load 2 is that the microwave generator 1 will be located near the place where sterilization needs to be performed, that is, near people. People need room lighting, and the addition of the microwave generator 1 enables sterilization of the air in this room. This makes it possible to provide good lighting and good air quality to the people in the room. The housing 3 is preferably configured to prevent the microwave radiation generated by the microwave generator 1 from exiting the volume 4 so that people located near the lighting device are not exposed to the microwave radiation. It should be noted that even if some microwave radiation leaks into the room, this is not harmful to the people present in the room. In contrast, UV-C leaking into the room is harmful to people. Therefore, it should be noted that sterilization using microwave radiation is significantly safer than sterilization using UV-C. Although the present invention is advantageous for people, it may be applied mutatis mutandis to animals in the context of agriculture and provide the same advantages. The housing 3 may act like a Faraday cage.Furthermore, the housing 3 is configured to provide illumination by the illumination load 2 to external objects inside the room. Preferably, the housing 3 has a plurality of openings that allow the light generated by the illumination load 2 to exit the housing 3. In order to prevent the microwaves generated by the microwave generator 1 from exiting the housing 3, the maximum size of the openings may be such that it does not exceed the wavelength of the microwaves. Preferably, the maximum size of the openings of the housing 3 is 1 / 10 or less of the wavelength of the microwaves. This enables optimal blocking of microwaves by the housing 3 while allowing for good openings for light to pass through. The housing 3 having the openings can be configured in a mesh shape such that an even distribution of light is provided to the surroundings, for example, external objects. The mesh may function as a Faraday cage. The mesh may look like a lampshade, and the openings of the mesh may be selected such that microwave leakage is intentionally created, for example, there is more lateral leakage and less downward leakage of the ceiling lighting fixture. In the case of a wall-mounted lighting fixture, leakage may be created such that only upward or wall-shearing external microwaves are created.

[0039] The microwave generator 1 provides microwaves that are used to sterilize volume 4. Volume 4 is surrounded by the housing 3. In volume 4, there are particles and pathogens that need to be sterilized or destroyed. The particles can be, for example, aerosol droplets containing virus particles. The microwave generator 1 generates microwaves in volume 4 such that the particles are exposed to the microwaves. The particles absorb the energy present in the microwaves. By absorbing energy from the microwaves, the virus or pathogen within the particles is inactivated. The microwave energy is transferred to the virion by a process called structure resonant energy transfer (SRET). The virion can be considered as a homogenous ball. This ball has mechanical vibration modes. These modes include the zeroth mode where the virion expands and contracts equally in all directions (also called the "breathing" mode), the dipole mode where the core and shell of the virion vibrate relative to their initial positions, the quadrupole mode where the virion gets squeezed alternately along two perpendicular directions, etc. Among these modes, the dipole mode is the one that couples to the incident microwave electromagnetic radiation. The coupling is quite strong, and in many cases, the energy transfer from the microwaves to the mechanical vibrations is 100%. The frequency of the microwaves is preferably between 300 MHz and 300 GHz. Preferably, a microwave frequency of 8.2 GHz is used. At this frequency, the virus particles resonate best and absorb most of the power. Therefore, at this frequency, the power required by the microwave generator 1 to inactivate the virus is minimized.

[0040] To prevent the housing 3 from allowing microwaves to escape from the volume 4, the housing 3 may be adapted to absorb microwaves. This may be done using a non-conductive material such as plastic. Also, the thickness of the non-conductive material may determine to what extent microwave radiation can leak through the housing 3. Under the definition of preventing microwaves from escaping from the housing 3, it should be understood that although most of the microwave radiation does not escape from the housing 3, leakage of microwave radiation outside the housing 3 may still occur. Conductive materials are very well suited to reflecting microwaves and preventing them from passing through the housing 3. Preferably, the conductive material is metal. Metals can very well absorb microwaves and are also very well suited to forming the housing 3. Examples of preferred metals are iron, copper, and aluminum.

[0041] The housing 3 may include a non-conductive and visible light transmissive cover that covers at least a portion of the openings present in the housing 3. This may be done to prevent unwanted substances from being (accidentally) introduced into the volume 4. Further, it may prevent a person from inserting a finger into the volume 4. Therefore, it may be desirable to cover at least the openings that can be reached by hand after at least the lighting device is attached with a non-conductive and transparent cover.

[0042] Figure 2 shows an improved example of the lighting device in Figure 1. The lighting device shown in Figure 2 may have all the technical features provided in Figure 1. Preferably, the lighting device has a microwave generator 1, a lighting load 2, a housing 3, and a volume 4. Further, the lighting device may have a presence sensor 5. The presence sensor 5 may be used to detect the presence of people indoors. The lighting device may be arranged in this room. When the presence of people is detected, the lighting device may respond accordingly. For example, upon detection of presence, the lighting device may turn on the lighting load 2. Additionally, or alternatively, the lighting device may turn on the microwave generator 1. It is preferable to perform sterilization only when people are in the room. Since people are spreaders of pathogens, it makes sense to perform sterilization only when people are present. A person entering the room may also prefer that the room is illuminated. In this case, both the microwave generator 1 and the lighting load 2 may be activated upon detection of presence. Non-limiting examples of the presence sensor 5 may include a passive infra-red (PIR) sensor, a radio detection and ranging (RADAR) sensor, a thermopile sensor, or a camera, etc.

[0043] Figure 3 shows another improved example of the lighting device of Figure 1. The lighting device shown in Figure 3 may have all the technical features provided in Figure 1. Preferably, the lighting device has a microwave generator 1, a lighting load 2, a housing 3, and a volume 4. Further, the lighting device may have a presence sensor 5 as shown in Figure 2. The housing may be provided with an air inlet 8 and an air outlet 9. The use of the air inlet 8 and the air outlet 9 may be desirable when a specific air flow is preferred or required. This is the case, for example, when the lighting device is part of an air flow system in a building. The air flow system may supply an air flow to the lighting device through the air inlet 8. This may be done, for example, using a hose coupled to the air inlet 8. In this case, the air outlet 9 may supply, for example, sterilized air to a room where people may be present. More generally, the air inlet 8 may be an opening for receiving air that needs to be sterilized. In this case, the air outlet 9 may be used to supply sterilized air to the room. An air flow generator may be used to enable air to flow effectively from the air inlet 8 to the air outlet 9 and pass through the volume 4. Non-limiting examples of the air flow generator may include a fan, an ion wind generator, etc.

[0044] Similar to the example provided in FIG. 1, the lighting device may have a non-conductive and transparent cover disposed in the housing 3. In this example, the non-conductive and transparent cover may be used to enable the air flow to be regulated from the air inlet 8 to the air outlet 9. The non-conductive and transparent cover may block the air from passing through, leaving the air inlet 8 and the air outlet 9 as optimal air inlets and outlets for the volume 4. In the example provided, the air inlet 8 and the air outlet 9 are positioned such that the air flow is directed towards the lighting load 2. This enables the lighting load 2 to be cooled by the air flow. The air inlet 8 and the air outlet 9 may be disposed at both ends of the volume 4.

[0045] FIG. 4 shows another improved example of the lighting device of FIG. 1. The lighting device shown in FIG. 4 may have all the technical features provided in FIG. 1. Preferably, the lighting device has a microwave generator 1, a lighting load 2, a housing 3, and a volume 4. Further, the lighting device may have a presence sensor 5 as shown in FIG. 2. The housing 3 may be provided with an air inlet 8 and an air outlet 9. The air inlet 8 may be provided with an ionizer 6. The ionizer can be used to supply ions to the air flow. The ions interact with the pathogens and weaken the pathogens before they enter the volume 4. In this case, the weakened pathogens can be more easily inactivated by the microwave radiation in the volume 4. The ions are generated with a predetermined polarity. Positive ions or negative ions can be generated. Preferably, the housing 3 is set to the same polarity as the ions so that the collision between the housing 3 and the ions is avoided without the ions being attracted to the housing 3. In this example, it may be desirable to provide a non-conductive and transparent cover on the outside of the housing 3 so that contact with the housing 3 from the outside, for example by a person, can be avoided.

[0046] In the example provided, the lighting load 2 is used to emit light. Non-limiting examples of lighting loads include incandescent lamps, fluorescent lamps, high-intensity discharge lamps, or light-emitting diodes, etc. Preferably, the lighting load has a light-emitting diode (LED). LEDs are very energy-efficient and can operate well even in an environment where microwave radiation exists.

[0047] The example provided in the figure shows some embodiments of the lighting device. The lighting device can be arranged in an array so that a larger surface can be illuminated. At the same time, a larger volume can be sterilized.

[0048] Upon consideration of the drawings, the present disclosure, and the appended claims, other variations to the disclosed embodiments can be understood by those skilled in the art and can also be implemented when practicing the claimed invention. In the claims, the word "comprising" does not exclude other components or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain means are recited in mutually different dependent claims does not indicate that a combination of these means cannot be used advantageously. No reference signs in the claims should be construed as limiting the scope.

Claims

1. a microwave generator for generating microwaves into a volume, the microwaves for sterilizing the volume; and a lighting load for emitting light for illuminating an external object; Housing and 1. A lighting device comprising: Air outside the lighting device is introduced into the housing, and the air irradiated with the microwaves is discharged, the housing is configured to enclose the volume and to prevent the microwaves from passing through the housing and to be transparent to the light; The lighting device includes a presence sensor for detecting the presence of a person or animal in a space, and upon detection of presence, the microwave generator is activated.

2. The lighting device of claim 1 , wherein the housing has a plurality of openings, each opening of the plurality of openings having an effective diameter of less than or equal to 1 / 10 of a wavelength of the microwaves.

3. The housing has a surface. at least a portion of the surface includes a coating for reflecting the microwaves; The lighting device of claim 1 , wherein the surface faces the microwave generator and the microwaves are reflected into the volume.

4. The lighting device of claim 1 , wherein the housing comprises a conductive material, the conductive material configured to prevent the microwaves from passing through the housing.

5. 5. The lighting device of claim 4, wherein the conductive material is a metal.

6. 10. The lighting device of claim 1, wherein the microwave generator generates microwaves having a frequency between 300 MHZ and 300 GHz.

7. 10. The lighting device of claim 1, wherein the microwave generator is controllable independently of the light source.

8. The lighting device comprises: an air inlet and an air outlet for respectively allowing air to enter and exit the volume; an airflow generator for enabling the air to flow from the air inlet to the air outlet; The lighting device of claim 1 , comprising:

9. 10. The lighting device according to claim 8, wherein the air inlet and the air outlet are arranged such that air flows over the light source to provide cooling for the lighting load.

10. The lighting device of claim 9 , wherein the housing comprises a non-conductive transparent cover.

11. 10. The lighting device of claim 1, wherein the microwave generator generates microwaves having a frequency of 8.2 GHz.

12. 2. The lighting device of claim 1, wherein air is supplied to the volume through the housing at a first location, and the apparatus includes an ionizer coupled to the first location for ionizing air entering the volume to a first potential, the housing being set to the first potential.

13. The lighting device of claim 1 , wherein the lighting load comprises a light emitting diode.

14. 14. An array of lighting devices, each of said lighting devices being according to any one of claims 1 to 13, said array of lighting devices being arranged in a grid.

Images