WO2015116987A1

WO2015116987A1 - Mobile, fixed reflector ultraviolet disinfection device

Info

Publication number: WO2015116987A1
Application number: PCT/US2015/013887
Authority: WO
Inventors: Todd A. PRINGLE
Original assignee: Twilight Labs, Inc.
Priority date: 2014-01-30
Filing date: 2015-01-30
Publication date: 2015-08-06
Also published as: WO2015116982A1; WO2015116876A1; WO2015116996A1

Abstract

A mobile ultraviolet disinfection device comprising a plurality of ultraviolet lamps, a plurality of reflectors, and a support structure, wherein the plurality of reflectors are attached to the support structure such that they reflect a field of light emitted by the plurality of ultraviolet lights into a surrounding space to be disinfected, and wherein the shape of the reflectors and the spatial relationship between the reflectors and the ultraviolet lamps is such that the field of light is a substantially uniform radial field.

Description

MOBILE, FIXED REFLECTOR ULTRAVIOLET DISINFECTION DEVICE

CLAIM OF PRIORITY

[0001] This patent document claims the benefit of priority of Pringle, U.S. Provisional Patent Application Serial Number 61/933,568 entitled "MOBILE ULTRAVIOLET DISINFECTION DEVICE", filed on January 30, 2014, and of Pringle, U.S. Provisional Patent Application Serial Number 61/933,539 entitled "PREDICTION AND OPTIMIZATION OF ULTRAVIOLET LIGHT IN AN ENCLOSED SPACE", filed on January 30, 2014. The entire contents of both provisional applications are hereby incorporated by reference.

TECHNICAL FIELD

[0002] The present invention relates generally to the disinfection of an enclosed space using a mobile device emitting ultraviolet light, including ultraviolet-C (UVC), and more particularly, to a mobile device emitting UVC utilizing reflectors.

BACKGROUND

[0003] Mobile UV disinfection devices can be used to disinfect enclosed spaces such as hospital rooms, locker rooms, food processing facilities, and other locations where surface disinfection is desired. [0004] U.S. Patent 8,841,634 teaches an Ultraviolet Germicidal Irradiation (UVGI) disinfection process utilizing a ring of cylinder shaped housings containing a UVC lamp mounted to a rotatable assembly containing a substantially flat aluminum reflector. U.S. Patent 8,841,634 also teaches a configurable UVC emission field by increasing or decreasing individual lamps based information from corresponding UVC radiometric sensors. [0005] U.S. Patents 6,656,424 and 6,911,177 teach a plurality of vertical UVC lamps in a ring with a plurality of UVC radiometric sensors on the top of the lamp assembly. The device continues to power all lamps until all of the sensors have received a desired amount of only reflected UVC light.

[0006] U.S. Patent 8,816,301 teaches a ring of slanted lamps with and without reflectors, and a mechanism to move lamps and reflectors in order to focus UV within a vertical band. [0007] U.S. Patent 8,105,532 teaches a UV light sterilizing wand utilizing a distance sensor to calculate accumulated direct UV light irradiance, including an indicator to the user when said accumulated irradiance, or dosage of UV light, has been achieved.

[0008] U.S. Patent 7,459,694 teaches non-vertical (slanted) ring of lamps in a cone

configuration.

[0009] U.S. Patent 4,843,521 teaches a double involute shaped reflector.

[0010] U.S. Patent 5,008,593 teaches a UV lamp reflector that can be of a group consisting of elliptical, parabolic, involute, and spherical.

[0011] U.S. Patent D684,671 shows and describes a four-bulb UVC mobile disinfection device with a central reflector mast consisting of four reflecting, substantially semicircular concavities.

SUMMARY OF THE INVENTION

[0012] The present inventors have recognized, among other things, that a problem to be solved includes the high expense of mobile UVC devices. UVC lamps and lamp drivers are expensive. Mobile UVC devices utilizing fewer lamps, but with added reflectors, can reduce costs of both materials and manufacturing labor, but a device utilizing reflectors and fewer lamps can have increased non-uniformity of the UVC emission field. Prior art mobile UVC devices with reflectors generate non-uniform radial UVC emission fields. It can be desirable that a mobile UVC disinfection device have a uniform radial UVC emission field when UVC disinfecting an enclosed space. A non-uniform radial field can result in some areas of the enclosed space receiving less UVC energy than others, requiring disinfection treatment times be calculated based on the radial zones with the least UVC output, or requiring that the operator carefully place the device in a specific location at a specific radial orientation. In an example, the present subject matter can provide a solution to this problem, such as by a reflector and lamp assembly configured to produce a uniform, or nearly uniform, radial UVC emission field.

[0013] The present inventors have recognized, among other things, that a problem to be solved includes the inefficiency of mobile UVC devices. Mobile UVC devices are limited by their electrical power which can be limited to 1800 watts for a 120 VAC 15 amp breaker. UVC lamps can also be susceptible to efficiency loss when not operated at the proper temperature.

Furthermore the present inventors have recognized, among other things, that another problem, regarding mobile UVC device inefficacy, to be solved includes avoiding photon losses from UVC devices resulting from photons leaving one lamp and being absorbed by the reflector, or passing through another lamp, or reflecting off the device reflector and passing through a lamp, including the same lamp that created the photon. Lamp walls consisting of inorganic materials such as quartz can absorb a fraction of the UVC photons that pass through the lamp wall. UVC lamps can have Teflon or other polymer encapsulating sleeves to contain broken fragments and protect the lamps. These sleeves can absorb about 10% or more of the UVC photons that pass through the sleeves. Photons entering or re-entering a sleeved UVC lamp can be absorbed, and therefore lost, from at least five events: the sleeve, the lamp wall, the plasma within the lamp, the lamp wall again on the back side of the lamp relative to where the passing photon entered, and the sleeve again on the back side. In an example the present subject matter can provide a solution to this problem, such as by incorporating heat sinks into the reflectors of the mobile UVC device. In another example, the present subject matter can provide a solution to this problem, such as by a reflector and lamp assembly configured to prevent all, or nearly all, photons from passing through another lamp or re-passing through the lamp that generated the photon.

[0014] The present inventors have recognized, among other things, that a problem to be solved includes the hazards and regulations of broken UVC lamps containing sharp fragments and mercury. The risk of breakage is highest with mobile UVC devices when moving or when people or equipment is moving around the devices. UVC lamps can be encapsulated in polymer sleeves to contain broken fragments, the UVC lamps can be protected by thick quartz shields, but these protections can reduce the efficiency of the UVC device by absorption of UV photons. UVC lamp assemblies can be mechanically enveloped by a non-transparent shield when being moved or stored but these protection require removal by operators which is time consuming and laborious. In an example the present subject matter can provide a solution to this problem, such as by a reflector assembly of a mobile UVC device consisting of at least two segments which can open and close.

[0015] The present inventors have recognized, among other things, that a problem to be solved includes the hazards of exposure to UVC light by human eyes and skin. This hazard makes it necessary to have administrative and engineering controls in place to prevent mobile UVC device from accidentally exposing people to harmful UVC light. Mobile UVC devices must be turned off when unprotected people are present, such as when the device must be moved to a new location. Turning off and on a mobile UVC device can results in lost time because of the necessary time for UVC lamps to warm up and come up to full output. In an example the present subject matter can provide a solution to this problem, such as by a reflector assembly of a mobile UVC device consisting of at least two segments which can open and close, where the mobile UVC device can maintain power to the UVC lamps, even with the reflector in the close position.

[0016] The present inventors have recognized, among other things, that a problem to be solved includes ineffectively disinfecting an enclosed space. Mobile UVC devices do not disinfect every surface of an enclosed space to the same level of disinfection. It can be desirable that a mobile UVC disinfection device have a configurable non-uniform radial UVC emission field when UVC disinfecting an enclosed space. It can be desirable, for example, to configure a UVC emission field to apply more UVC photons to the bed in a hospital patient room because a hospital bed has many more occlusions, recesses, or shadowed areas, requiring more photons, than typical hospital patient room walls. To create a configurable radial emission field, one can utilize a large array of vertical lamps, and electrically drive the output to each lamp individually, which can increase cost and complexity, and which can also decrease the efficiency of the device if the lamps are electrically driven outside of their most efficient operating zone. Another approach is to have multiple devices placed in the room, each device having a parabolic reflector to concentrate UVC light at a desired area, which increases cost and complexity as more devices must be utilized. In an example the present subject matter can provide a solution to this problem, such as by a mobile UV device with a plurality of lamps, and a reflector assembly of at least two segments, or plurality of reflector assemblies of at least two segments, configured to change shape and to open and close, and a rotation mechanism to rotate at least one reflector assembly.

BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A shows a typical device of the prior art utilizing a four-lamp design with semicircular or roughly parabolic reflectors.

[0018] Figure IB shows a typical device of the prior art utilizing a ring of lamps and no reflectors.

[0019] Figure 2 shows one embodiment of the invention utilizing a four-lamp design with reflectors consistent with the teachings of this invention. [0020] Figure 2a is provided for illustrative purposes and provides background information on the creation of an involute shape.

[0021] Figure 2B is provided for illustrative purposes and provides background information on the design of a double involute shape for a reflector. [0022] Figure 3 is a cross-sectional view of a double involute reflector design illustrating how the reflector directs reflected photons away from being reabsorbed by the lamp.

[0023] Figure 4 shows an alternate embodiment of the invention utilizing a three-lamp design consistent with the teachings of this invention.

[0024] Figure 5 shows an alternate embodiment of the invention utilizing reflectors consistent with the teachings of this invention designed such that each half of the reflector is rotatably mounted on a hinge mechanism such that the two halves can be collapsed together to form a protective enclosure for the lamps.

[0025] Figure 6 shows the alternate embodiment of the invention of Figure 5 showing the hinged reflector halves in the closed position, creating a protective enclosure for the lamps. [0026] Figure 7 shows an alternate embodiment of the invention wherein the hinged reflector mechanism can be rotated around the lamp to create alternate configurations of the invention.

[0027] Figure 8 shows the alternate embodiment of the invention of Figure 7, showing the reflector mechanisms rotated into a non-uniform reflectance pattern.

[0028] Figure 9 shows a single, hinged, rotating reflector mechanism in nine separate configurations, wherein each configuration is created by varying either the degree to which the reflector halves are closed or open or the angle of rotation of the entire reflector mechanism, or both.

[0029] Figure 10 illustrates how the configurable reflectance field embodiment could be used in a hospital room to concentrate ultraviolet light on items more likely to host germs, such as the railings on a hospital bed.

[0030] Figure 11 shows an embodiment with integrated heat sinking.

[0031] Figure 12 shows the lack of uniformity of the radial UVC emission field of the prior art. [0032] Figure 13 shows a comparison between the prior art and an embodiment of the invention.

DETAILED DESCRIPTION

[0033] It should be apparent by one skilled in the art that several mechanical and electromechanical mechanisms could enable the described embodiments.

[0034] Reference will now be made in detail to certain claims of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the enumerated claims, it will be understood that they are not intended to limit those claims. On the contrary, the invention is intended to cover all alternatives, modifications, and equivalents, which can be included within the scope of the invention as defined by the claims.

[0035] References in the specification to "one embodiment," "an embodiment," "an example embodiment," and the like, indicate that the embodiment described can include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one of ordinary skill in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0036] Values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of "about 0.1% to about 5%" or "about 0.1% to 5%" should be interpreted to include not just about 0.1 % to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range.

[0037] In this document, the terms "a," "an," or "the" are used to include one or more than one unless the context clearly dictates otherwise. The term "or" is used to refer to a nonexclusive "or" unless otherwise indicated. In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section. Furthermore, all publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference should be considered supplementary to that of this document; for irreconcilable inconsistencies, the usage in this document controls.

[0038] The term "about" as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range. When a range or a list of sequential values is given, unless otherwise specified any value within the range or any value between the given sequential values is also disclosed.

[0039] The term "substantially" as used herein refers to a majority of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999%) or more. [0040] The term "multiple" refers to two or more (e.g., 2, 3, 4, 5, 6, etc.).

[0041] The term "UVGI" refers to Ultraviolet Germicidal Irradiation, such as a common process used to control the spread of dangerous microbes.

[0042] The term "ultraviolet light" refers to electromagnetic radiation with a wavelength shorter than human- visible light, such as about 10 nm to about 400 nm. [0043] The term "UVC" (e.g., ultraviolet C, short-wave ultraviolet, FAR-UV, deep UV) refers to the band of UV light between about 100 nm and about 300 nm. Further, a subset of UVC includes, UV light lying between the wavelengths of about 200 and about 300 nm, commonly referred to as the "germicidal region" because UV light in this region can be lethal to

microorganisms including, but not limited to, bacteria, protozoa, viruses, molds, yeasts, fungi, nematode eggs, or algae. An especially destructive wavelength of UV light is about 260 nm.

Germicidal UV lamps typically emit light with a wavelength that is substantially close to 260 nm for its destructive purposes, such as around typically around 254 nm.

[0044] The terms "lamp" and "bulb" will refer to a source of UVC light used in an ultraviolet disinfection device. [0045] The term "absorbing" refers to the process by which a photon is prevented from transmitting through, refracting, or reflecting from a material.

[0046] The term "specular reflection" and "specularity" refers to mirror-like reflection of light from a surface, in which light from a single incoming direction is reflected into a single outgoing direction.

[0047] The term "light scattering", "diffusively reflect", or "diffuse reflection" refers to reflection of light from a surface or sub-surface such that an incident ray is reflected or scattered at many angles rather than at just one angle as in the case of specular reflection.

[0048] Figure 1 A shows a typical ultraviolet disinfection device of the prior art utilizing a four- lamp design with semi-circular reflectors. The view in Figure 1 A is cross-sectional, showing the arrangement of components as seen from above as they appear in a cross-section.

[0049] In a typical prior art device 100, a plurality of lamps 10 are placed around a central mast structure 20, such that they radiate outward for the purposes of disinfecting a room by emitting ultraviolet light in the form of UVC photons 15. The lamps 10 are housed inside of semi- circular reflectors 30, the purpose of which are to reflect most of the UVC photons 15 that strike the surface of the reflectors 30, distributing them ideally out into a room or area needing to be disinfected. In Fig. 1 A, UVC photons 15 are shown as dashed arrows, which represent the path from the lamp 10 out into the room, or into the surface of the reflectors 30, where they are redirected or absorbed depending on the reflectivity of the reflector. Dashed lines shown as 15a are also UVC photons, but are labeled separately to indicate they re-enter a lamp where they can pass through or be absorbed by the lamp 10. For the purposes of this specification, both reference designators, 15 and 15a, will represent UVC photons, with 15a indicating photons that are subject to reabsorption by a lamp.

[0050] The reflectors 30 are shaped to take the UVC photons 15 that are emitted from parts of the lamp 10 facing away from the room to be disinfected and reflect them back out into the room. By using reflectors 30, the UVC photons 15 can be focused out into the room, and the number of UVC lamps 10 can be reduced while still delivering UVC photons into the room. Unfortunately, the semi-circular design of the reflectors 30 is flawed, in that it often reflects UVC photons 15a back into the lamps 10 where they are absorbed and lost, reducing the effectiveness of the ultraviolet disinfection device 100. Additionally, the shape of the reflectors 30 creates a non-uniform field, further illustrated in figure 12 below. [0051] Figure IB shows another type of ultraviolet disinfection device typical in the prior art, utilizing a ring of lamps and no reflectors. Figure IB is cross-sectional, showing a ring of lamps as they would appear when viewed from above.

[0052] In this style of prior art device 105, a ring of UVC lamps 10 is arranged to emit UVC photons 15 (and 15a) out into an area to be disinfected. As there are no reflectors, or there may only be a minimally reflective support structure, to focus the light back out into the area, a higher number of lamps 10 is typically required to adequately cover the area to be disinfected by creating a suitably wide emissive area. Although a ring of lamps 10 is able to provide a fairly uniform field of UVC light, it is costly and inefficient. Many of the photons 15a emitted by the lamps 10 travel through the device 105 and strike other lamps 10, where they can be absorbed and lost. A fairly significant portion of the UVC photons 15/15a emitted by each lamp 10 can be lost to reabsorption by other lamps 10.

[0053] Figure 2 shows one embodiment of the invention utilizing a four-lamp design with reflectors consistent with the teachings of this invention. The figure is cross-sectional, showing the view from above of a horizontal cross section of this embodiment of the ultraviolent disinfection device 110.

[0054] In the embodiment shown in Figure 2, the invention is an ultraviolet disinfection device 110 comprising UVC lamps 10 with reflectors 35 built around a central mast structure 20 consisting of a novel modification of a double involute shape. It should be noted that the term "central mast structure", as used herein, refers to any appropriate means of supporting the surrounding lamps 10 and reflectors 35, and may be solid, a support framework, a center post, a housing containing control electronics, or any other appropriate structure. The exact nature of the central mast structure 20, in this embodiment, is not important to the fulfillment of the invention. The overall shape of the reflectors 35 and their relationship to the lamps 10 are key inventive concepts shown in Figure 2.

[0055] Referring temporarily to Figures 2a and 2b, we will discuss the involute shape used as the partial basis for reflectors 38 of the embodiment illustrated in Figure 2. Figure 2a illustrates the geometric definition of an involute curve 37 as it is created around a circle 47. The involute curve 37 for the circle 47 in Figure 2 A can be visualized as the curve traced by the free end of a string that is attached to a point on the circle and then wound around the circle 47, such that the normals of the curve are tangential to the circle 47. The dashed lines 42 in Figure 2 A represent various positions in time of such a string as it is wrapped around the circle 47 clockwise from its initial attachment point 48 to create the involute 37 of the circle 47. It is important to note that an involute curve can be created for curved shapes other than circles. The initial curve (such as the circle 47 in Figure 2A in this example) used to create an involute is known as an "evolute." That is, for every involute created, there is a corresponding evolute. [0056] Figure 2B provides background information on the design of a double involute shape for a reflector. If we imagine the circle 47 in Figure 2A is the UVC lamp 10 of the present invention, we can create one involute curve 37a around the lamp 10 in one direction and a second involute curve 37b of the same size in the other direction. We can now base the curve of the double involute reflector 38 on the shape created by superimposing involute 37a on top of involute 37b. The amount each involute 37a and 37b that is incorporated into the double involute shape 38 can vary depending on the points on the evolute where each involutes terminate. Figure 2B illustrates an example double involute with involute terminations roughly on opposite sides of the evolute.

[0057] Among the benefits for using a double involute reflector design is because the double involute reflector shape will reflect photons around the lamp, eliminating or virtually eliminating the photon loss due to reabsorption by the lamp. Figure 3 is a cross-sectional view of a double involute reflector design 38 illustrating how the double involute reflector 38 directs reflected photons 15 away from being reabsorbed by the lamp 10. The nature of the double involute curve 38 and its spatial relationship to the evolute curve of the lamp 10 ensures that most if not all of the photons 15 are passed around the lamp 10 and into the area to be disinfected.

[0058] As stated previously, the evolute curve does not have to be circular. If the ultraviolet disinfection device of the present invention utilizes lamps with an oval cross section instead of a circular one, the shape of the novel modification of the double involute reflector would be different than that shown in the example embodiments shown herein, although in an embodiment the starting involutes can be created in the same manner. The circular lamp cross section used in the examples in this specification are not intended to be limiting in any way. Any appropriate cross-sectional shape for a lamp could be utilized, along with the corresponding modified involute shape for the reflector, or other reflector shape consistent with the teaching of this invention. [0059] Using a pure double involute for the reflector shape will solve the problem of photon losses from photons re-entering lamps and being absorbed, but a pure double involute design will not produce a uniform radial field. To solve the problem of a non-uniform field, in one embodiment, the far wall of the involute shape is bent, similar to a winding action or unwinding action of the involute if it were a spiral spring. In another embodiment, the location of the involute terminations on the evolute are selected based on the effect on the emission field. In the example of a 4 bulb reflector the involute is bent inward in a manner that would shift the emission field of the double involute in the direction of the emission field of a parabola a small amount. How far, in what manner, and how much the double involute is modified can depend on the number of bulbs in the assembly, and other factors. The modified double involute shape of figure 2 is just one example embodiment. Starting with a double involute shape and modifying can have advantages because it starts with a shape that has zero photons that re-enter the lamp in a perfectly specular or mirror-like reflector. But it is not required that the double involute be the starting point of the design. A key inventive concept embodied in figure 2 is that the radial field, which combines direct light from the lamps and reflected light of the reflectors, be equal or nearly equal or substantially equal regardless of viewing angle around a cross sectional plain centered on the center of the reflector and bulb assembly. This equal or nearly equal field strength means that a measurement device traveling in a circle, centered around the assembly of lamps and reflectors, facing the assembly, will measure the same, or nearly the same, or substantially the same UV irradiance as it travels around the circle. During the travel around the circle the measurement device, as an example, a UV sensitive photodiode sensor, will be illuminated by light from different lamps, reflectors, and combinations of reflectors as it rotates around the circle, all while measuring the same, or nearly the same, or substantially the same irradiance. During some of the travel around the circle around an embodiment with three or four lamps, the sensor at times will be illuminated by just one lamp and its reflector, and at times by two lamps and their corresponding reflectors, and at times by unequal amounts of one lamp and reflector over a second lamp or reflector, all while measuring the same, or nearly the same, or substantially the same irradiance. Starting with a double involute and modifying the angles of the curvature, or modifying the involute termination points on the evolute, depending on the number of reflectors needed is but one method to achieve a uniform radial field. Other factors affecting the field shape include the consistency, UV photon absorbance, UV photon diffuse reflection or scatter, and UV photon specular reflection or mirror-like qualities of the reflector material. The best design tradeoffs for a mobile UVC device for a uniform field is affected by the reflection properties of the reflector material as well as the transmission and absorbance properties of the lamp, including any protective sleeves for the lamp. Another factor in the design consideration that can drive adjustments to the reflector shape and can impose tradeoffs is whether the concavity of the reflector is desired to be deep enough to protect the lamp from impacts. Determining the best reflector shape to produce a uniform field, or a substantially uniform field somewhat compromised by other design tradeoffs, can be obtained with mathematical modeling, computer modeling, iterative design with radiometric measurement, and other methods and combinations of methods. [0060] Figure 4 shows an alternate embodiment of the ultraviolet disinfection device 115 of the present invention utilizing a three-lamp design with reflectors consistent with the teachings of this invention, instead of a four-lamp design. The concepts described previously in this specification regarding the use and design of novel modification of the double involute reflectors, or other reflector shape consistent with the teachings of this invention, for a four-lamp design are applicable here and need not be repeated. Figure 4 is a cross-sectional representation of the three-lamp ultraviolet disinfection device 1 15, as seen from above. It has three UVC lamps 10, and three modified double involute reflectors 35, arranged around a central mast structure 20.

[0061] Figure 4 is included to demonstrate that the present invention is not limited to the use of four UVC lamps, and that any other appropriate number of UVC lamps can be used without varying from the inventive concept of the present invention. More than four lamps can be used as well as fewer lamps. One skilled in the art will know that the number of lamps and reflectors can be scaled up or down to meet the needs of an application or the specific requirements of a product. Configurable Field Device

[0062] The examples shown in Figures 2 through 4 show embodiments of an ultraviolet disinfection device utilizing a novel modification of a double involute reflector design and creating a uniform field of germicidal UVC light. That is, while the intensity of the lamps might be varied to change the overall power of the UVC light field generated, the position and shape of the reflectors are fixed. In the next examples, the inventors will show embodiments of the ultraviolet disinfection device of the present invention which will allow for a dynamic UVC field shape. That is, these examples will demonstrate embodiments of the ultraviolet disinfection device with a configurable UVC field.

[0063] Figure 5 shows an alternate embodiment of the ultraviolet disinfection device invention utilizing a novel modification of double involute reflectors designed such that each half of the reflector is rotatably mounted on a hinge mechanism such that the two halves can be collapsed together to form a protective enclosure for the lamps, or to shape the UVC light field emitted.

[0064] Figure 5 is again a cross-sectional representation, showing the view of a horizontal cross section of this embodiment of the invention, highlighting the shape and arrangement of the lamps and reflectors.

[0065] In this four-lamp embodiment 120, four UVC lamps 10 are placed with four configurable reflectors 35 a, and arranged around a central mast structure 20. In this embodiment of the device 120, the reflectors 35a are comprised of two halves connected together by a hinge 40, such that each half can be swiveled, via an actuating mechanism, on an axis parallel to the lamp 10 independently.

[0066] In the embodiment 120 of Figure 5, the two halves of the reflector 35 a are shown open and positioned such that they form a modified double involute shape, such as the uniform field embodiment 110 of Figure 2. When in this configuration, the configurable field embodiment 120 should perform identically, or nearly identically, to the uniform field embodiment 110 of Figure 2, as the open reflector halves 35a match the shape of the modified double involute reflectors in Figure 2.

[0067] Figure 6 shows the alternate embodiment of the ultraviolet disinfection device invention 120 of Figure 5, but now with the hinged reflector halves 35a in the fully closed, or nearly fully closed, position, creating a protective enclosure for the lamps 10 for storage and transport. In this fully closed position, the hinged reflector halves 35a may also be used as a protective barrier, allowing an operator to be in the room with the device and to turn the lamps on to warm them up before operation, or to move the device, without risk of UVC harming the operator or other people.

[0068] Figure 5 shows the configurable field embodiment of the invention 120 with the reflectors open to the "uniform field" position, and Figure 6 shows embodiment 120 with the reflectors closed around the lamps 10. It should be noted that the two halves of the reflector 35a can be moved independently of one another, and that they can be in positions ranging from fully open to fully closed. An operator can take advantage of this feature and adjust the reflector halves 35a to modify the shape of the UVC emission field of the device. This feature could be used to create specially-shaped UVC fields that concentrate more light in some areas and less in other. For instance, if the ultraviolet disinfection device 120 were placed in a doorway of a room to be disinfected, the lamps 10 facing the hallway outside the room could be completely closed off, while the reflectors 35a facing inside the room could be opened completely.

[0069] Figure 7 shows an alternate embodiment of the ultraviolet disinfection device invention 125 wherein the hinged reflector mechanism 35a can also be rotated around the lamp 10 to create additional alternate configurations of the invention. In embodiment 125, the hinged reflector 35a is mounted on a circular track or path 50, such that it can be rotated up to 360 degrees around the axis of lamp 10 without substantially occluding light from the lamp 10. In Figure 7, an embodiment ultraviolet disinfection device 125 is shown with the hinged reflectors 35a open in the shape of a modified double involute curve, and the reflectors 35a are rotated on circular track 50 such that embodiment 125 duplicates the performance of the uniform field embodiment 110 shown in Figure 2.

[0070] Figure 8 shows the alternate embodiment of the ultraviolet disinfection device invention of Figure 7, but this time with the hinged reflectors 35a rotated into new positions, independently of each other, to create a non-uniform, specifically configured UVC radial field. In Figure 8, some of the hinged reflectors 35a are closed partially, reshaping the reflector to focus the emitted UVC light, and some of the reflectors 35a are opened wide to distribute the emitted UVC reflectance field more broadly. Some of the reflectors 35a are also rotated about a circular track 50 to cast more UVC light in one direction.

[0071] Figure 9 shows a single, hinged, rotating reflector mechanism in nine separate configurations, wherein each configuration is created by varying either the degree to which the reflector haves 35 a are closed or open or the angle of rotation of the entire reflector mechanism 35a, or both. The three configurations on the far left column show the reflectors 35a completely closed, encasing and protecting the lamp 10, but rotated along circular track 50 to point in different directions. The three configurations shown in the middle column of Figure 9 show reflectors 35a about halfway open, but in different rotation angles. The three remaining configurations in the far right column of Figure 9 show the reflectors 35a open to the widely open curve shape. It should be obvious to one skilled in the art that each reflector-lamp mechanism on the ultraviolet disinfection device embodiment 125 of Figures 7 and 8 can be opened and rotated independently, to create a large number of UVC field shapes.

[0072] Figure 10 illustrates how the configurable reflectance field embodiment 125 could be used in a hospital room 300 (or similar environment) to concentrate ultraviolet light on items more likely to host germs, such as the railings on a hospital bed 200. In the example shown in Figure 10, two configurable reflectance field devices 125 are positioned on either side of a hospital bed 200 in a hospital room 300. On each device 125, three of the reflectors are rotated such that they focus their UVC light emissions on the bed 200 and especially on the sides of the bed 200 where the railings are located. The remaining reflector on each device is opened wide and facing away from the bed, to cast a broad, unfocused field of UVC light on the exterior walls of room 300.

Integrated Heat Management

[0073] Figure 11 shows an example of integrated heat sinking 310 attached or co-extruded with the reflector material. This allows for improved temperature control allowing for higher output lamps and can eliminate the need for cooling fans used in the prior art. In one embodiment, the four lamp uniform field reflector mast is an aluminum extrusion with integral heat sinking.

Experimental Results of Uniform Field Embodiments and Prior Art

[0074] Figure 12 shows results of radiometric sensor measurements of the prior art. The inventors measured, using calibrated UVC sensors, the radial emissive field at a fixed point from a mobile UVC device with a reflector mast and lamp configuration consistent with figure 1 A. Two levels of refiectivity were used in the experiment. A highly reflective and predominantly specularly reflective aluminum reflector 320 was measured which resulted in a very non-uniform field in an "X" or four pointed star pattern. The specularity was then reduced be using an anodized aluminum surface with some diffuse characteristic 330 which resulted in significant loss in total output, about 20% reduction in output, and still resulted in a non-uniform field of square-like configuration, though the filed non-uniformity was reduced by the increased diffuse reflections. Because a non-uniform radial field can result in the problem of some areas of the enclosed space receiving less UVC energy than others, requiring disinfection treatment times be calculated based on the radial zones with the least UVC output, or requiring that the operator carefully place the device in a specific location at a specific radial orientation, neither field output of the prior art in Figure 12 provides a solution. Note that the lowest measured irradiance point of each field 340 is at the same level of output for both the higher reflectivity and specular reflector 320 and the more anodized and somewhat diffuse reflector 330, meaning that in terms of their lowest region of radial output, there is no benefited from the change in diffuse to specular reflection, even though the more specular reflector 320 has less photon losses. [0075] Figure 13 shows the results of radiometric sensor measurements comparing the prior art to an embodiment of the invention. The inventors measured, using calibrated UVC sensors, the radial field at a fixed distance from a mobile UVC device with a reflector mast and lamp configuration consistent with figure 1 A in the prior art 330 compared to a reflector mast and lamp configuration embodiment 350 consistent with Figure 2 following the teachings of this invention. Note that we compare the more uniform field example of the prior art 330 from figure

12 to the embodiment 350. Note that the embodiment 350 is nearly circular compared to significantly much less uniform and square-like field of the prior art 330. Note also the lowest measured irradiance point of the prior art field 340 is much lower than the lowest measured irradiance point of the embodiment field 360. In this example, the embodiment 350 consisted of the same aluminum of high reflectivity and specularity as 320 in Figure 12 but the shape of the reflector of the embodiment 350 is consistent with the teachings of this invention. Note that the shape of the reflector in the embodiment 350 allows for highly reflective and specular material without the field the non-uniformity in the prior art. The embodiment's lowest measured irradiance point 360 measured 42% more output than the lowest measured irradiance point 340 of the prior art. The embodiment 350 in figure 13 solves the problem of lack of efficiency and lack of uniformity in the radial fields of mobile UVC devices utilizing reflectors.

[0076] A key inventive concept embodied in Figure 2 and Figure 4 and demonstrated in Figure

13 is a uniform radial field of maximum output for a given lamp output. With a circular or nearly circular uniform radial field, the lowest irradiance point for surfaces illuminated by the

UVC device is also the highest point, eliminating the need to take into account the radial orientation of the device when disinfecting a room, and eliminating the need to discount the output of the device to its lowest point for circumstances where careful radial orientation placement is not practical. The teachings of this invention enables UVC devices to be more effective, have more output, take less time for treatment, cost less, accurate in targeting surfaces for disinfection, and the achievement of other benefits.

EXAMPLE 1

[0077] A mobile UVC device consisting of four vertical 64-inch 350W high output amalgam UVC lamps, lamp driver and control circuits, a base with casters, a user interface, a high reflectivity and highly specular aluminum extruded reflector mast with a reflector for each bulb concavity of a modified double involute shape, modified to the teachings of this invention, configured to produce a uniform emissive field. EXAMPLE 2

[0078] A mobile UVC device consisting four vertical 64" 300W high output amalgam UVC lamps, lamp driver and control circuits, a base with casters, a user interface, a high reflectivity and highly specular aluminum reflector of a modified double involute shape for each bulb consisting of two substantially similar reflector pieces hinged at a central point at the trough point of the concavity for each bulb and electro-mechanical actuators to open and close or open to specific angles.

[0079] A mobile UVC device consisting four vertical 64" 325W high output amalgam UVC lamps, lamp driver and control circuits, a base with casters, a user interface, a high reflectivity and highly specular aluminum reflector of a modified double involute shape for each bulb consisting of two substantially similar reflector pieces hinged at a central point at the trough point of the concavity for each bulb and electro-mechanical actuators to open and close or open to specific angles, with each reflector assembly for each lamp mounted to a rotating mechanism with electro-mechanical rotatory actuators to orient the reflector assembly.

Claims

1. A mobile ultraviolet disinfection device comprising

a plurality of ultraviolet lamps;

a plurality of reflectors; and

a support structure;

wherein the plurality of reflectors are attached to the support structure such that they reflect a field of light emitted by the plurality of ultraviolet lights into a surrounding space to be disinfected; and

wherein a shape of the reflectors and a spatial relationship between the plurality of reflectors and the plurality of ultraviolet lamps is such that the field of light is a substantially uniform radial field.

2. The mobile ultraviolet disinfection device of claim 1, further comprising control

electronics.

3. The mobile ultraviolet disinfection device of claim 1, wherein the quantity of ultraviolet lamps is equal to the quantity of reflectors, and wherein the reflectors are arranged radially around the support structure, and each ultraviolet lamp is placed within a reflector.

4. The mobile ultraviolet disinfection device of claim 1, wherein the shape of the reflectors is a modified double involute curve.

5. A method of disinfecting an enclosed space, comprising the steps of

placing a mobile ultraviolet disinfection device with a substantially uniform radial field in the enclosed space; and

irradiating the enclosed space with the mobile ultraviolet disinfection device.