Technical field

The present disclosure relates to a liquid purifying drink container device and in particular to sterilize liquid in a liquid purifying drink container by irradiating the liquid with ultraviolet light.

Background

Using ultraviolet (UV) light is an environmentally friendly way of sterilizing liquids, surfaces and air. By using short- wavelength ultraviolet (UV-C) light, microorganisms are killed or inactivated by destroying nucleic acids and disrupting their DNA, leaving them unable to perform vital cellular functions. Ultraviolet disinfection is a purely physical, chemical-free process, and thus is highly suitable for drinking water.

Numerous water containers for ultraviolet light treatment have been described. As an example, US Patent Application 2011/174993 and US Patent 8975596 both describe water purifying drink containers including a liquid container, a cap assembly removably coupled to the liquid container, and a purification assembly using a mercury lamp that emits ultraviolet light in the germicidal spectrum to purify a volume of drink liquid held in the liquid container. US-2006/0231476 relates to a portable, refillable water dispenser serving batches of water purified of organic and inorganic pollutants that includes a portable, refillable and hand-holdable vessel for holding and pouring water. The lower part, referred to as a "still water processing module", comprises a UV-light source that is intended to provide UV radiation that is omnipresent to every region in the lower part. The UV-light source is a cold cathode fluorescent lamp.

US Patent 4755292 describes a portable ultraviolet water sterilizer comprising a mercury ultraviolet lamp. US Patent 6042720 discloses an apparatus for storing and disinfecting a fluid using a UV source arranged in a lid.

Traditional water purifying assemblies often use mercury-vapor lamps. Such lamps emit light at 254 nm, which is within the range of wavelengths that demonstrate a strong disinfecting effect. The optimal wavelengths for disinfection are close to 260 nm.

However, the use of mercury is not suitable in consumer products, due to the toxicity of mercury to the environment as well as the user. In US-7300634 is a photocatalytic cleaner for air or water disclosed. A UV light source is required to activate Titanium dioxide to create free radicals and charged particles that will react with bio and viral contaminants, thus decomposing these contaminants into harmless compounds. In order to avoid UV light sources that contains mercury it is suggested to use a field emission lamp. Various phosphor materials are applied to achieve emission of wavelengths within the absorption band of the Ti02 (approx. 350 nm).

Safety is important when using ultraviolet light, as exposure can cause damage to e.g. skin and eyes, such as sunburn, increased cancer risk, and temporary or permanent vision impairment. Thus an object of the invention is to provide a liquid purifying container device that is easy to use and with a high user and environmental safety.

Summary

The above-mentioned object is achieved by the present invention according to the independent claim. Preferred embodiments are set forth in the dependent claims.

An environment-friendly water purifier container device (e.g. a pitcher or flask) is provided to treat water or other drinking liquid by UV-radiation emitted by a UV-source unit using field emission technology. The container device is designed to be used by the end user immediately before consuming the liquid, e.g. water. Thereby, it is possible to provide a quick and safe way of purifying drinking water just before consumption.

The UV emitting field emission lamp can be mounted in a lid of the container or within the container itself, e.g. protruding into the liquid from the bottom or side wall, or at one or several sides of the inside of the container. In the simplest form, the lamp is activated by pushing a button or the like. However, as an alternative the lamp may be activated by e.g. closing of the lid. The lamp typically needs about 30 seconds to kill off any harmful organisms in a liter of water. Preferably the water within the container cannot be accessed before enough time has passed, to ensure drinkable water after treatment. Various safety arrangements are provided to ensure that no UV-light may escape from the container during UV-light emission. These arrangements include a UV-light non- transmissive container wall, and mechanisms to turn off the UV-light if the lid not is in a closed position, only allowing activation of the UV-light source unit when predefined rules are fulfilled.

In some embodiments the container further comprises a UV light sensor arranged such that it can detect and monitor the amount of UV radiation that has passed through the volume of liquid, to ensure adequate purification. In such an embodiment, the time of radiation can be adjusted and/or controlled according to the amount of radiation detected by the UV sensor. This is particularly applicable if the liquid contains particles that hinder the UV light to some degree, which might then necessitate a longer time of UV radiation for effective purification.

The intended use of the disclosed liquid purifier container device is for purifying water or other liquids, such as sports beverages, fruit juices or other beverages, including beverages prepared by mixing e.g. powder or a concentrate with water, such that they are fit for consumption without the risk of a user becoming ill due to any bactericidal or microbial infection.

For consumer products it is important that only environmentally acceptable materials are used. For example, using UV-light sources that include mercury is not environmentally acceptable, due to risk for non-acceptable disposals. Using a field emission lamp has the advantage of avoiding any harmful mercury in the product, which is especially important as the UV-light source is in close proximity to the liquid to be treated, and that the container is used directly by an end user in a variety of settings. Thus, there is no risk of mercury contamination of either the user or the environment when using a field emission lamp in the product.

Using a field emission light source also has the advantage of instant turning on and off of the light, which saves time and energy. Brief description of the drawings

Figure la and lb show schematic cross-sectional views of a liquid purifying drink container device according to an embodiment of the present invention.

Figure 2 shows a schematic cross-sectional view of another liquid purifying drink container device according to an embodiment of the present invention.

Figure 3 shows a schematic cross-sectional view of yet another liquid purifying drink container device according to an embodiment of the present invention.

Figure 4 shows a schematic cross-sectional view of still another liquid purifying drink container device according to an embodiment of the present invention.

Figures 5-12 show schematic cross-sectional views of still other embodiments of the liquid purifying drink container device according to the present invention.

Figure 13 illustrates a field emission ultraviolet light source unit, applicable to be used in the container device according the present invention.

Figure 14 shows a schematic cross-sectional view of a liquid purifying drink container device according to a further embodiment of the present invention.

Detailed description

The liquid purifying drink container device will now be described in detail with references to the appended figures. Throughout the figures the same, or similar, items will have the same reference signs. Moreover, the items and the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.

Field emission light sources are based on two physical phenomena: field emission and cathode luminescence. A high voltage, typically approximately 10 kV, is applied over a cathode and corresponding anode structure. The anode structure can comprise a luminescent layer and a thin transparent conducting layer, coated on the inside of e.g. a lamp glass. A lamp glass can be part of a bulb-shaped arrangement, a cylindrical light source or a flat display. When the voltage is applied, electrons are emitted from the cathode and strike the luminescent layer of the anode, creating light. This light passes through the transparent conductive layer and out of the lamp glass. Two important advantages of this technology are the almost instant activation time, which is advantageous with regard to energy consumption, and the lack of environmentally- hazardous substances.

Examples of field emission light sources are described in US20020070648A1,

US7134761 , WO2005074006A1 and US20110018427A1. Specifically, in US20110018427A1 a field emission display is disclosed having a flat surface.

Figure 13 is a schematic illustration of an ultraviolet field emission light source unit 12 applicable in the container device according to the present invention. As mentioned, a liquid purifier container device as will be described herein comprises a field emission lighting arrangement for producing UV light within an internal liquid compartment 4 of the liquid purifier container device. The produced UV light has a wavelength being in the germicidal spectrum, which will be discussed in detail below. An exemplary field emission lighting arrangement is shown schematically in figure 13 in a cross-sectional side view, and comprises at least one field emission cathode structure 16 and at least one anode structure 18. The anode structure 18 is in this variation configured as a layered structure on the inside of an enclosing sleeve 20, e.g. a lamp glass. The anode structure 18 comprises a conductive material configured to receive electrons from the field emission cathode structure 16, and a light emitting material configured to be activated by the electrons and thereby emit ultraviolet light having a wavelength within the range of 240- 300 nm, and more particularly within the range of 240-270 nm.

Thus, the ultraviolet light source unit may further comprise an envelope structure, i.e. the enclosing sleeve 20, configured to enclose the cathode and the anode structure, wherein the envelope structure is made from a material which is transparent to ultraviolet light. The enclosing sleeve may be made from natural or synthetic quarts glass, UV-transparent glass, or borosilicate glass.

Several examples of liquid purifier container devices 2 are shown in figures la, lb, 2-12, 14, having a volume of up to 3 liters, and preferably 0.75-1 liters, where the container device 2 comprises an ultraviolet light source unit 2 in the form of a field emission lighting arrangement or lamp. A liquid purifier container device 2 comprises a liquid compartment 4 for holding liquid enclosed by a liquid compartment wall 10, and the ultraviolet light source unit 2 is arranged within or adjacent to the liquid compartment.

The liquid purifier container device 2 may have any suitable outer shape, such as cylindrical, spherical, cone-shaped, cubical, bottle shaped or any regular or irregular shape, e.g. a shape and design suitable for use at home or a shape that enables easy carrying by a user. The liquid purifier container device 2 may also comprise a handle 9 of any suitable shape for easy transport, as shown in figures 2 and 3, for instance on a side, as shown, or on top of the container device.

The internal liquid compartment 4 may also have any suitable shape, preferably a shape that matches the outer shape of the container device 2 and/or maximizes the liquid volume to be treated in relation to the overall shape of the container device 2.

The ultraviolet light source unit 12 can be arranged in a variety of configurations in relation to the liquid compartment 4 as is illustrated in the figures. As shown in figures la and lb, the ultraviolet light source unit 12 may be arranged on an inner side wall of the liquid compartment. As shown in figures 2 and 3, the ultraviolet light source unit 2 may be arranged at the bottom of, or at the top of, respectively, the liquid compartment along a longitudinal axis of the device. In figure 4 the UV light source unit 12 is an integral part of the compartment wall 6. Figure 5 illustrates a configuration similar to the one illustrated in figure 2 but provided with a removable power source unit 26. In figure 6 a removable combined power source and UV-light source unit 32 is illustrated, where a UV light transparent window 34 is provided in the compartment wall 6. Figures 7-12 illustrate other variations of embodiments comprising a removable combined power source and UV-light source unit 32, and finally, figure 14 illustrates an embodiment comprising an integrated combined power source and UV-light source unit 50.

The ultraviolet light source unit 12 is configured as a generally elongated shape in figures 1-3, 5, 7-12, and 14, but may also have any suitable outer shape, such as elliptical, spherical, flat, bulb-shaped etc., as long as, when in use, the emitted UV light can reach essentially the full volume of the liquid compartment 4, such that the entire volume of liquid is treated efficiently. This will be discussed in detail below. In one embodiment, which is illustrated in figure 4, the UV light source unit 12 is an integral part of at least a part of the liquid compartment wall 6. Thus, the UV light source unit 12 then has a generally curved layered structure where a cathode layer structure 16 is positioned outside an anode layer structure 18. The outside of the cathode layer structure is covered by a protective layer, e.g. plastic, and the inside of the anode layer structure is covered by a UV-light transmissive material, e.g. glass or plastic, that is environmentally accepted with regard to the liquid in the liquid compartment. In figure 4 a cross-sectional view along the longitudinal axis of the container is illustrated. In the figure is illustrated a variation of the embodiment where a part of the wall 12, e.g. half of the circumference of the container, includes the UV light source unit embodied by the cathode layer structure 16 and the anode layer structure 18. Thus, in this embodiment the field emission light source unit is an integral part of the wall and thereby achieves two purposes, both as a UV light source but also forming a structural part of the container device.

The liquid purifier container device 2 also comprises an opening 8 (fig. lb) for filling and emptying of liquid in the liquid compartment 4, and a lid 10 adapted to close the opening and being in a closed position where liquid is prevented from leaking out from the compartment, and UV-light during the treatment period is prevented from escaping from the compartment. The lid 10 may be attached by an attachment member 5 in any suitable way, wherein the attachment member 5 can be, for instance, a hinge, anchoring member or a cord. As an alternative the lid 10 can be fully removable from the container device 2, i.e. not be provided with an attachment member.

The lid 10 may be provided with threads, a friction attachment component or any other suitable attachment component for attaching the lid 10 in position to close the opening 6. When the lid 10 is in a closed position, the liquid compartment 4 is effectively sealed such that liquid and UV-light cannot leak out of the compartment. Figure la and figure 2 illustrate a container device 2 with a closed liquid compartment 4, and figure lb illustrates the same container device as in figure la with the lid 10 in an open position, wherein an opening 8 for accessing the liquid is provided. Figure 3 shows a similar lid 10, where the only difference from the previous figures is that the lid 10 does not cover the entire top of the container device 2. The dotted lines show the lid when in an open position. The sealing function of the lid 10 can be provided in a number of ways, including any suitable manner as is known in the art. The attachment and sealing function may be combined in one solution, or be effected by two separate components. For example a seal 7, in the form of a sealing material such as rubber or silicone, may be arranged on the lid or adjacent to the opening 8. This seal may be provided such that effective attachment and an effective seal are achieved, or a seal can be combined with e.g. threads for attachment.

A purifier container device 2 may also be provided with a spout 11 (figure 3).

In the embodiments illustrated in figures 1-4 the field emission light source unit is preferably energized by a power source unit being integrated in the container device, e.g. a battery or batteries, or a rechargeable battery. When a rechargeable battery is used a charging input may be provided for connecting the battery to a charging device, or the rechargeable battery may be removed and charged by a dedicated device. This applies naturally also to the embodiments described in the following with respect to the power source unit 26, to the combined power source and ultraviolet light source unit 32, and also to the integrated combined power source and ultraviolet light source unit 50. The capacity of the power source unit 26 or the combined units 32, 50, being a rechargeable battery, is typically such that at least 20-30 UV-light doses may be generated. As an alternative, a connection may be arranged for connection to an external energy source.

The specific range of ultraviolet light to be emitted from the light source unit can be customized by using different light emitting materials, where each light emitting material produces light of specific wavelengths, e.g. a single wavelength or a range of wavelengths. One example of such a material is e.g. a phosphor layer. The light emitting materials emitting light of different wavelengths can be used individually in the light source, or combined, by e.g. mixing different materials in powder form and coating the anode structure with such mixtures.

It has been found that an optimal wavelength range for killing biological material is 240- 300 nm.

The shape of the field emission lamp can be adapted to any suitable and desired shape, e.g. such that the UV radiation emitted can reach all parts of the liquid volume within the container. In addition, this also means that the container itself can be adapted to a variety of shapes, while still ensuring adequate UV radiation throughout the volume of liquid within the container.

As mentioned above, the object is to achieve a consumer product where water is purified at the point of use - just prior the water is to be consumed, with the intention to optimize the effectiveness of the treatment while ensuring ease of use for the consumer.

Preferably, in an active mode, the container cannot be opened. During active mode the UV-source emits UV-light in the germicidal range for killing off bacteria and other organisms that might be present in the water. A lid may be arranged to prevent access through the opening when in the active mode to prevent that liquid is poured out from the pitcher prior the treatment is completed.

The field emission UV-light source may have different shapes as mentioned above, and in one embodiment the UV-light source has a circular cylindrical shape and is placed along a symmetrical axis of the container device. Thereby the entire volume of water is effectively treated.

The treatment time may be in the range of 30-120 seconds for a container of 0.75-3 liters. The energy consumption is very low, e.g. 10-20 Watts per treatment.

Now, the liquid purifying drink container device will be disclosed in detail with references to the drawings.

Thus, a liquid purifying drink container device 2 is provided, comprising a liquid compartment 4 for holding a liquid, e.g. water, and being enclosed by a liquid

compartment wall 6, an opening 8 is provided for filling and emptying of liquid in the liquid compartment 4. It is further provided with an openable lid 10 structured to close the opening and hinder access to the liquid compartment when the lid is in a closed position. The container device further comprises an ultraviolet (UV) light source unit 12 adapted to emit ultraviolet light in the germicidal spectrum, and being arranged such that the ultraviolet light is emitted inside the liquid compartment 4. The ultraviolet light source unit 12 comprises a field emission lighting arrangement 14 comprising at least one field emission cathode structure 16 and at least one anode structure 18. The anode structure comprises a conductive material configured to receive electrons from the field emission cathode structure, and the anode structure further comprises a light emitting material configured to be activated by the electrons and thereby emit ultraviolet light.

The ultraviolet light source unit preferably comprises a sleeve 20 configured to enclose the cathode structure and the anode structure, and that the sleeve 20 is made from a material which is transparent to ultraviolet light. Furthermore, the conductive material is transparent to ultraviolet light and arranged as a layer on the inside of said sleeve.

The sleeve has an outer shape that is adapted to the specific design of the container device, and may e.g. have a bulb shape, or a cylindrical shape, e.g. a cylindrical shape having a circular cross-section.

In one embodiment, illustrated in figure 4, the ultraviolet light source unit 12 is an integral part of at least a part of the liquid compartment wall 6.

To ensure that no UV-light may escape from the container device the compartment wall 6 is structured to prevent UV-light from being transmitted through the compartment wall - that is applicable to all embodiments and variations disclosed herein.

In order to further increase the efficiency of the UV-light treatment and to reduce the treatment time period at least a part of the inner surface of the compartment wall 6 is preferably structured to reflect UV-light by covering the inner surface with a UV-light reflective layer, e.g. smooth aluminum or stainless steel.

The ensure that the container device remains closed during UV-light treatment to prevent that UV-light escapes from the device a locking arrangement 22 (see figure 5) is provided for locking the lid 10 during a specified time period related to the activation time of the UV light source unit 12.

In order to further optimize the treatment of the liquid an ultraviolet light sensor 24 may be arranged within said liquid compartment 4 for measuring exposure of the liquid within the liquid compartment to ultraviolet light. This feature is illustrated in figure 5 but is applicable to all embodiments disclosed herein.

In one embodiment the time period for locking the lid 10 is based on an obtained measurement of the ultraviolet light sensor 24, i.e. when the measured UV-light dose exceeds a predetermined threshold, e.g. related to the liquid, a control signal is applied to the locking arrangement 22 to unlock the lid. This procedure is performed by a control unit 40 which is shown in figure 5 but is applicable to all embodiments disclosed herein.

With reference to figure 5, the container device comprises, according to one embodiment a removable power source unit 26. The liquid compartment 4 is structured to be removably attached to the power source unit 26 and is provided with mechanical and electrical members 28 to cooperate with corresponding mechanical and electrical members 30 at the power source unit 26 such that the liquid compartment 4 is mechanically steered into a correct position where an electrical connection is establish in order to energize the UV light source unit 12. These mechanical and electrical members 28, 30 are only

schematically illustrated, but may have a similar construction as in commonly used electric kettles.

In the illustrated container device the UV light source unit 12 has a cylindrical shape extending from the bottom of the liquid compartment. However, the removable power source unit 26 may be applied to all embodiments illustrated herein where the UV light source unit 12 is arranged within the liquid compartment, or where it is an integral part of the compartment wall.

In another embodiment the ultraviolet light source instead is an integral part of the removable power source unit. Various examples of this embodiment are illustrated in figures 6-12. Thus, the liquid purifying drink container device then comprises a removable combined power source and ultraviolet light source unit 32. The combined unit 32 may be provided with one or many batteries, e.g. rechargeable batteries, or being connectable to mains voltage. The ultraviolet light source unit is configured to be activated only when the liquid compartment 4 has been correctly removably attached to, or docked to, the combined unit 32. The compartment wall 6 of the liquid compartment 4 is provided with a UV transparent window 34 through which UV-light emitted by the ultraviolet light source unit of the combined unit 32 may reach the liquid within the compartment 4.

In the variation illustrated in figure 6 the UV light source unit 12 has an essentially flat upper surface to be arranged such that the emitted UV light reaches the liquid in the compartment via the UV transparent window 34, which is arranged at the bottom of the container wall. As an alternative, the combined unit including the UV light source unit may be arranged outside the liquid compartment at other positions than the bottom, e.g. at a side wall, which then is provided with a UV transparent window. Attachment members are then provided, not shown in the figures, to easily attach the combined unit and position it correctly.

Another variation is illustrated in figures 7-12. In figures 7 and 10 two variations of the container device 2 are illustrated in an assembled state ready for liquid treatment, during treatment or after treatment. In figures 8 and 11 the two variations of the combined unit are illustrated, and in figures 9 and 12 two variations the liquid compartment 4 removed from the combined unit are illustrated. The only difference between the two variations is the size of the UV light source unit, where the length is considerably shorter in the variation illustrated in figures 10-12. Thus, in this embodiment the UV light source unit 12 is structured as an extending member 36 having a UV-transparent sleeve 20. The liquid compartment 4 is provided with a mating receiving cavity 38 having a UV transparent wall into which cavity 38 the UV-transparent sleeve may be inserted when the liquid compartment 4 is docked to the combined unit 32, which is illustrated in figures 7 and 10.

When using the container device 2 at home it is often practical to have it at the table or at the kitchen worktop in order to have it available when needed. Therefore, the container device described herein and in particular the embodiments including the power source unit 26 or the combined power source and UV light source unit 32 is structured to be arranged at a flat surface, e.g. a table, such that the device is in a fixed upright position during use. The container device 2 is preferably provided with a control unit 40 configured to control the activation of the UV light source unit 12 by applying a set of activation rules. The activation rules include that the UV light source unit only is activated when the liquid compartment is correctly docked to the power source unit or to the combined power and light source unit, and that a presumption for activation of the UV light source unit is that the lid of the liquid compartment is in a closed position. Furthermore, the control unit 40 comprises activation rules such that it is configured to control the activation time of the UV light source based upon the measured UV-light dose. In the daily use of the container device it is an important aspect for the user to know if the liquid in the container device has been treated. To provide an indication to the user the device comprises an indication member 42 configured to indicate when a purifying procedure has been performed, and being controlled by the control unit 40. The indication member 42 is illustrated in figure 5 but may be applied in all embodiments disclosed herein. The indication member may e.g. comprise a light emitting diode (LED) or a display.

In a further embodiment the liquid purifying drink container device 2 comprises a cleaning member structured to clean surfaces subjected to UV-light from fouling or scaling which may aggregate on the surfaces. The cleaning member is preferably a mechanical cleaning member, e.g. a ring that may be moved along the sleeve enclosing the UV-light source in order to mechanically remove any aggregated material. Furthermore, the cleaning member may be accomplished by providing a thin anti-fouling layer at the sleeve. Thus, the cleaning members are provided to clean off the lamp surface to prevent fouling/scaling from deteriorating the UV-light emission. The cleaning members may be mechanically coupled to the lid such that when closing/opening the lid, cleaning is inevitably performed.

In still another embodiment the container device 2 comprises at least one stirring member 46 (schematically illustrated in figure 5) arranged within the liquid compartment to provide a flow of the liquid within the compartment, during UV-light activation. Using a stirring member for the liquid to be purified results in a more efficient purification in that the induced liquid flow will result in that the entire liquid volume more rapidly will be subjected to the UV-light, i.e. a mixing flow condition is achieved during UV-light activation. The liquid flow is schematically indicated by arrows. Examples of such arrangements are e.g. a magnetic stirrer, a rotating propeller. The stirring member may be intermittently or continuously activated prior the activation of the UV-light, or during the UV-light activation. The stirring member is preferably controlled by the control unit 40 according to a dedicated activation rule.

With references to the schematic block diagram in figure 14 a further embodiment of the container device will now be described. Generally, this embodiment relates to an integrated container device where the liquid compartment wall encloses an integrated combined power source and UV-light source unit 50. Preferably, the UV light source 12, comprising the field emission lighting arrangement, is mounted along the longitudinal axis of the device as illustrated in the figure. However, any other position within the container device as previously described is possible. With regard to the other features illustrated in figure 14, it is referred to the above description, e.g. in relation to figure 5. An integrated container device is in particular advantageous during outdoor use.

The present invention is not limited to the above-described preferred embodiments.

Various alternatives, modifications and equivalents may be used. Therefore, the above embodiments should not be taken as limiting the scope of the invention, which is defined by the appending claims.