Refrigerator glazing

Abstract

Refrigerator glazing (100), including - at least one optical waveguide (1) for guiding radiation (3) in the IR wavelength range with a first surface (I) and a second surface (II), - at least one radiation source (2) for radiation (3) in the IR wavelength range from λ = 1.3 µm to 3.5 µm, - an outer disc (11) and - a spacer (7) which is arranged between the optical waveguide (1) and the outer disk (11), wherein the radiation source (2) is arranged to the optical waveguide (1) in such a way that the radiation (3) emitted by the radiation source (2) can be coupled into the optical waveguide (1).

Description

[0001] The invention relates to a refrigerator glazing and a refrigerator with such glazing.

[0002] Refrigeration appliances such as refrigerators and freezers are frequently used to extend the shelf life of perishable foods or medications. The low temperatures inside these appliances slow down chemical reactions and biological processes that can otherwise render food inedible and medications unusable. Glass-fronted refrigeration appliances, particularly refrigerators and freezers, have become standard in retail stores. These appliances allow customers to see the contents without opening the unit. This saves energy, as opening the appliance results in energy loss, and also makes it easier to find the desired products.

[0003] A common problem with glass-fronted refrigerators is the condensation of the glass surfaces exposed to the interior. When these surfaces come into contact with warm air upon opening the refrigerator, the moisture in the ambient air condenses on them. This results in reduced visibility through the refrigerator's glass.

[0004] To prevent condensation on surfaces, coatings are frequently applied to the glass surfaces of refrigerators. For example, DE2454657A1 discloses a coating based on phosphorus pentoxide that counteracts condensation. EP1499218B1 discloses a coating based on various isocyanates for a refrigerator door, which partially prevents or inhibits fogging or clouding of the refrigerator door. Another particularly energy-intensive solution is the continuous heating of the glass surfaces using heating wires or heating layers.

[0005] These well-known solutions, however, have the problem that they usually do not completely prevent the glass from fogging up, but often only inhibit condensation. Furthermore, these coatings wear down over time; for example, they degrade due to the glass's exposure to UV radiation or are slowly worn away by contact with the glass. Continuous heating, on the other hand, has a high energy consumption.

[0006] Regardless of these solutions, DE102017201190A1 relates to a refrigeration appliance, for example a refrigerator, in which the condition of food is checked using an IR-conducting shelf. For this purpose, IR radiation in a wavelength range of 780 nm to 3000 nm is coupled into a light-conducting area of ​​the shelf. An IR radiation detector simultaneously measures the IR radiation that emerges from the shelf at another point. The condition of certain foods can be determined based on the difference between the emitted and emitted radiation.

[0007] WO2023073593A1 relates to a glazing unit comprising at least one optical fiber into which IR radiation in the range of 780 nm to 4000 nm can be coupled for the removal of condensation or frost. The glazing system is primarily designed for vehicle windows but can also be used in refrigeration equipment.

[0008] US2017013679A1 discloses a vehicle windshield arrangement in which IR radiation is directed onto an IR-absorbing pane. The absorption by the pane heats it, allowing water and frost to be removed. The pane is made of a material with high absorption of the emitted radiation. Similarly, WO2017137111A1 discloses a glazing system for a vehicle in which a radiation source is arranged in a recess of a light-guiding pane. The radiation emitted by the radiation source is at least partially coupled into the pane and serves to monitor elements within the pane or to heat the pane.

[0009] The present invention aims to provide a refrigerator glazing that overcomes the aforementioned disadvantages, is safe for users, and has lower energy consumption. The invention also aims to provide a refrigerator with such glazing.

[0010] The object of the present invention is achieved according to the invention by a cooling device glazing according to claim 1 and a cooling device according to claim 14. Preferred embodiments are described in the dependent claims.

[0011] The refrigerator glazing according to the invention comprises at least one optical waveguide for guiding radiation in the IR wavelength range and at least one radiation source for radiation in the IR wavelength range from λ = 1.3 µm to 3.5 µm, hereinafter also referred to as IR radiation. The radiation source is arranged relative to the optical waveguide such that the radiation emitted by the radiation source can be coupled into the optical waveguide. The wavelength λ (lambda) is defined as the smallest distance between two points of the same phase of a wave. The refrigerator glazing is designed as multiple glazing and also comprises an outer pane and a spacer arranged between the optical waveguide and the outer pane. The refrigerator glazing thus comprises at least the outer pane and a further pane. The further pane is, for example, an inner pane on which the optical waveguide is applied as a coating.Alternatively, the optical fiber can also be designed as a single disk, thus forming the other disk. The refrigerator glazing can also comprise more than two disks; preferably, it comprises at least three disks.

[0012] Preferably, the refrigerator glazing is an insulating glass unit with at least one inner pane and one outer pane connected by a spacer. The optical fiber is preferably the inner pane, i.e., the pane intended to be adjacent to the interior of the refrigerator. Alternatively, the optical fiber can also be a coating on the inner pane. The refrigerator glazing can also have more than two panes and, for example, be triple glazing. Refrigerator glazing refers to glazing for refrigeration appliances such as refrigerators and freezers. The refrigerator glazing is intended to separate the interior of the appliance from the external environment through an opening. It is particularly preferably the glazing of the refrigerator door, which can also refer to a refrigerator flap or sliding door.

[0013] According to the invention, the optical waveguide has a first surface and a second surface. The first surface is designed to face the external environment when installed in a cooling appliance. The second surface is designed to face the interior of the cooling appliance when installed in a cooling appliance. According to the invention, the first surface of a pane that forms part of the cooling appliance glazing is designed to face the external environment when installed in a cooling appliance. According to the invention, the second surface of a pane that forms part of the cooling appliance glazing is designed to face the interior of the cooling appliance when installed in a cooling appliance.

[0014] The radiation source couples infrared radiation in a wavelength range of λ = 1.3 µm to 3.5 µm into the optical waveguide. Due to the lower refractive index of water compared to glass, the coupled infrared radiation can be selectively coupled out by ice or water on the surface of the optical waveguide. This results in absorption of the infrared radiation and excitation of water molecules in ice crystals and water droplets, causing the ice to melt and the water to evaporate. Energy loss through convection is advantageously largely eliminated. The refrigerator's glass remains free of condensation or icing, and visibility through the glass is maintained even with frequent opening of the refrigerator.

[0015] Coupled IR radiation refers to the propagation of IR radiation within the optical waveguide by utilizing the effect of total internal reflection. This process takes advantage of the fact that the surfaces of the optical waveguide are either transparent to IR radiation or reflect it, depending on the angle of incidence of the radiation and the refractive index of the adjacent medium. A combination of reflection and transmission is also possible. As mentioned, whether the IR radiation is reflected or transmitted by the optical waveguide depends on the angle of incidence θ1 of the IR radiation on the surface of the optical waveguide, which forms the interface between the optical waveguide and the adjacent medium. Interfaces of the optical waveguide refer to the surfaces of the optical waveguide where it meets an adjacent medium. Examples of an adjacent medium include air or water.The angle at which IR radiation is reflected also depends on the refractive index of the optical waveguide n1 and the refractive index of the adjacent medium n2 (for example, optical waveguide = glass and adjacent medium = air). Whether the IR radiation is deflected or completely reflected at the interface (exit angle θ2) can be estimated using Snell's law of refraction. (n1n2sin(θ1)=sin(θ2)).

[0016] The reason why IR radiation can be coupled out at the wet glass surface, while it is reflected at the glass surface adjacent to air, is the change in the angle of total reflection θ. T IR radiation at the interface between water and glass (contact surface with water). The angle of total internal reflection indicates the angle at which the incident light is totally reflected: n2n1=sin(θT). Water has a refractive index of approximately 1.3, glass has a refractive index of approximately 1.5, and air has a refractive index of approximately 1.0. Therefore, the angle of total internal reflection is larger at the interface between glass and water than at the interface with air. In other words, there is a range of angles of incidence in which IR radiation is totally reflected at the glass-air interface, whereas at the glass-water interface it is at least partially reflected.

[0017] A major advantage of the invention is that it eliminates the need for large-area, electrically heated coatings, such as silver layers or anti-fog coatings. This leads to a simplified and more cost-effective manufacturing process for the refrigerator glazing. The selective heating of water using IR radiation also saves energy costs. The transmission of high-frequency radiation, for example, for receiving mobile phone signals, communicating with cloud servers ("Internet of Things"), and similar applications, is not affected by the IR radiant heating system according to the invention, resulting in further advantages. By coupling the IR radiation into the optical fiber, it is largely prevented from escaping into the external environment and therefore poses no health risk to users of the refrigerator.Those residual components of the IR radiation that are not coupled out at moist areas of the optical fiber according to the invention are instead coupled out to a large extent via the circumferential edge surface of the optical fiber. The technical effect of energy savings is further enhanced by the use of multiple glazing comprising an outer pane, since this reduces the amount of heat generated by the external environment on the optical fiber, thus saving energy for cooling the interior of the cooling unit.

[0018] The optical waveguide, particularly when designed as a disk, preferably a glass disk, has a circumferential edge surface. This circumferential edge surface comprises a top edge and a bottom edge, as well as two side edges connecting the top and bottom edges. In its installed position, the upward-facing edge is referred to as the top edge, and the downward-facing edge of the optical waveguide as the bottom edge. The edges running between them are referred to as side edges. If the optical waveguide is a coating on a disk, preferably a glass disk, the coated disk also has a circumferential edge surface with a top edge, a bottom edge, and side edges.

[0019] In a particularly preferred embodiment of the invention, the radiation source is arranged such that its position relative to the optical fiber does not change even when the refrigerator glazing is moved. This means that, for example, if the refrigerator glazing is part of a refrigerator door or flap that can be opened and closed, the radiation source is positioned in the same way relative to the optical fiber even during opening or closing and at the respective starting and ending points of the refrigerator door. In this case, the radiation source could, for example, be attached to an upper edge, lower edge, and / or side edge of the optical fiber or the pane coated with it. This also means that the relative position of the optical fiber to the radiation source is the same everywhere, regardless of location.This ensures efficient heating regardless of the refrigerator's position (e.g., open or closed). Preferably, the radiation source is permanently attached to the optical fiber, preferably by bonding. If the optical fiber is a coating on a disc, preferably a glass disc, the radiation source can also be permanently attached to this disc, preferably by bonding. The adhesive used for bonding is preferably an optically clear adhesive based on polyacrylic compounds.

[0020] In a further preferred embodiment, the radiation source is suitable for emitting IR radiation in the IR wavelength range from λ = 2.5 µm to λ = 3.3 µm, preferably from λ = 2.6 µm to λ = 3.1 µm, and particularly preferably from λ = 2.6 µm to λ = 2.9 µm. Absorption and excitation of water molecules, and thus the resulting heating and evaporation, are particularly high in this preferred wavelength range. Advantageously, it has been found that the transmission of glass in the wavelength range from λ = 2.9 µm to λ = 3.1 µm is particularly high at over 70%, and especially at approximately λ = 3.0 µm at approximately 85%, so that the energy can be used efficiently for de-icing and evaporating water.

[0021] In an alternative embodiment, the radiation source is suitable for emitting IR radiation in the IR wavelength range from λ = 1.45 µm to λ = 1.95 µm. In this range, the radiation is particularly energy-intensive and therefore very suitable for evaporating water. This wavelength range is especially preferred when the radiation source comprises or consists of an LED, since LEDs with radiation in higher wavelength ranges above 2 µm are difficult to manufacture and therefore incur high costs.

[0022] The radiation source used emits radiation in the infrared range from 1300 nm to 3500 nm, for example, radiation in the range from 1600 nm to 3100 nm, but particularly preferably in the range from 2900 nm to 3100 nm. It is not necessary for the emission band of the radiation source to completely cover these ranges. However, the emission band should lie (at least partially) within these ranges. When in use, the radiation source is expediently connected to a power supply.

[0023] The radiation source preferably comprises at least one LED, OLED, and / or a laser diode, preferably at least one LED. In particular, the radiation source comprises at least one LED, which can also be referred to as an "IR radiation-emitting diode." Furthermore, the radiation source can comprise laser diodes or lasers, which have the advantage of being particularly powerful and efficient. In addition to the aforementioned elements for generating IR radiation, the radiation source can also comprise other elements, for example, a housing in which the elements for generating IR radiation are mounted. Alternatively, the radiation source can be an LED, OLED, and / or a laser diode.

[0024] In a particularly preferred embodiment of the invention, the radiation source comprises or consists of an Er:YAG diode. The Er:YAG diode has a wavelength of approximately 2960 nm. This wavelength corresponds to the wavelength range in which water molecules exhibit the highest absorption coefficient. Other examples are InAs / GaSb and Er³⁺-doped sesquioxide diodes.

[0025] The refrigerator glazing can also incorporate more than one radiation source, for example, two, three, or four. The minimum radiation source can be, for instance, ribbon-shaped or spot-shaped. Other geometric shapes are also possible. Several individual radiation sources can be arranged side-by-side, spaced apart, or in a ribbon-like configuration (close together). In other words, if several spot-shaped LEDs are arranged next to each other, a multi-part, ribbon-shaped radiation source can be created. This allows for flexible adjustment of the number and intensity of the radiation sources to the specific requirements for heating the refrigerator glazing, such as the spatial and geometric conditions and the energy required for efficient heating.

[0026] The optical waveguide can, for example, be designed as a disk. Alternatively, the optical waveguide can be applied as a coating to one of the disk's surfaces (not the outer disk), particularly the surface facing the interior of the cooling unit. It is especially preferred that the optical waveguide be applied as a coating to both the second and first surfaces of the disk. Thus, the disk is coated with the optical waveguide on each of its main surfaces. Preferably, in this embodiment, the cooling unit glazing includes a further radiation source, such that the first radiation source couples IR radiation into the optical waveguide on the first surface of the disk, and the further radiation source couples IR radiation into the optical waveguide on the second surface of the disk.

[0027] In a preferred embodiment, the optical waveguide is formed as a disk, preferably a glass disk, particularly preferably made of soda-lime glass. However, the disk can also be made of other types of glass (for example, borosilicate glass, quartz glass, aluminosilicate glass). Alternatively, the disk can also be made of plastic, i.e., transparent polymers, for example, polycarbonate. The thickness of the disk can vary widely. Disks with a thickness in the range of 0.5 mm to 10 mm are preferred, more preferably from 1 mm to 5 mm. Preferably, the optical waveguide is a glass disk and particularly preferably has an iron oxide content of no more than 1%. This low iron oxide content of the glass disk makes it particularly suitable as an optical waveguide for IR radiation.

[0028] In an alternative embodiment, the optical waveguide is applied as a coating to a disk (not the outer disk), and the disk is preferably made of glass, particularly preferably of soda-lime glass. However, the disk can also be made of other types of glass (for example, borosilicate glass, quartz glass, aluminosilicate glass). Alternatively, the disk can also be made of plastic, i.e., transparent polymers, for example, polycarbonate. The thickness of the disk can vary widely. Disks with a thickness in the range of 0.5 mm to 10 mm are preferred, and preferably from 1 mm to 5 mm.

[0029] If a coating is formed on the basis of a material, it consists predominantly of that material, in particular essentially of that material, in addition to any impurities or dopants. For the purposes of this invention, "transparent" means a light transmission of visible light (according to ISO 9050:2003) of at least 70%, preferably at least 80%, and particularly preferably at least 90%. For the purposes of this invention, "semi-transparent" (according to ISO 9050:2003) means a light transmission of at most 70%, preferably at most 50%, and particularly preferably at most 30%. For the purposes of this invention, "opaque" means a light transmission (according to ISO 9050:2003) of less than 30%, preferably less than 20%, particularly preferably less than 5%, and particularly less than 0.1%.

[0030] According to the invention, the refrigerator glazing is a multi-pane unit, preferably an insulating glass unit, with at least one inner pane and one outer pane, which are connected to each other via a spacer. According to the invention, the spacer is arranged between the optical fiber and the outer pane. The optical fiber is particularly preferably the inner pane of the glazing or, alternatively, applied as a coating to the second surface of the inner pane. Particularly preferably, the optical fiber is designed as a single pane, and the spacer connects the outer pane and the optical fiber.

[0031] The refrigerator glazing is preferably an insulating glass unit with a maximum of one inner pane and one outer pane, such that the first surface of the outer pane is exposed to the external environment. However, the refrigerator glazing can also be an insulating glass unit with more than two panes. For example, the refrigerator glazing can be triple glazing comprising an inner pane, a middle pane, and an outer pane. In this case, the optical fiber is particularly preferably applied to the inner pane of the glazing or, alternatively, to the second surface of the inner pane as a coating. The inner pane is preferably connected to the middle pane via a spacer, and the middle pane is connected to the outer pane via another spacer.

[0032] The spacer is typically frame-shaped and positioned at the edge between the two discs to hold them (usually parallel) at a defined distance from each other. The spacer is typically made of a light metal (especially aluminum) or polymeric materials (for example, polypropylene or styrene-acrylonitrile). It is preferably in contact with the two discs via a sealant, particularly a butyl sealant. An outer sealant is preferably filled into the outermost gap between the discs, which is open to the outside. This outer sealant may be an organic sealant made of or based on polysulfides, silicones, room-temperature curing (RTV) silicone rubber, high-temperature curing (HTV) silicone rubber, peroxide-cured silicone rubber and / or addition-cured silicone rubber, polyurethanes, butyl rubber, and / or polyacrylates.The inner space between the panes, which is bounded and enclosed by the glass panes and the spacer, is preferably evacuated or filled with an inert gas, such as argon or krypton. The thermal conductivity is reduced by the space between the panes, thus enabling more energy-efficient temperature control within the refrigerator. The spacer typically has a cavity filled with a desiccant to protect the space between the panes from moisture ingress.

[0033] The inner pane, the outer pane, and any middle pane, as well as any additional panes, are preferably made of glass, particularly preferably of soda-lime glass. However, the panes can also be made of other types of glass (e.g., borosilicate glass, quartz glass, aluminosilicate glass). Alternatively, the panes can be made of plastic, i.e., transparent polymers, such as polycarbonate. The thickness of the panes can vary widely. Panes with a thickness in the range of 0.5 mm to 10 mm are preferred, and preferably from 1 mm to 5 mm.

[0034] The optical waveguide is preferably a transparent ceramic coating. The optical waveguide preferably has a layer thickness of at least 650 nm, particularly preferably from 700 nm to 5 µm, most preferably from 750 nm to 4 µm, and particularly preferably from 800 nm to 3 µm. The optical waveguide can contain or consist of titanium oxide, aluminum oxide, silicon nitride, particularly Si3N4, silicon zirconium nitride, silicon oxynitride, and / or silicon dioxide, particularly SiO2. The optical waveguide particularly preferably contains silicon nitride and / or titanium dioxide. In particular, the optical waveguide is based on a silicon nitride layer and / or a titanium dioxide layer. It can also consist of a silicon nitride layer and / or a titanium dioxide layer. These materials are particularly suitable as optical waveguides for IR radiation and additionally exhibit a high transmittance for visible light.

[0035] In a preferred embodiment of the invention, the refrigerator glazing also includes an IR-reflective coating. When the glazing is installed in a refrigerator, the IR-reflective coating is intended to prevent the emission of IR radiation into the external environment. The IR-reflective coating is preferably applied to the first or second surface of the outer pane or to the first surface of the inner pane. In the case of triple glazing, the IR-reflective coating can also be applied to the first or second surface of the middle pane. It is particularly preferred that the IR-reflective coating be applied to the first surface of the optical waveguide, especially if the optical waveguide is designed as a single pane.

[0036] The IR-reflective coating preferably extends over the entire visible area of ​​the refrigerator glazing. The IR-reflective coating preferably extends over at least 80% of the optical fiber's surface, and particularly preferably over at least 90%. Most preferably, the IR-reflective coating is arranged so that, when viewed through the refrigerator glazing, it is congruent with the optical fiber, i.e., extends over the entire surface of the optical fiber.

[0037] The IR-reflective coating can comprise metallic layers, for example, at least one metallic layer, or be metal-free. Particularly preferably, the IR-reflective coating comprises at least one silver layer and preferably several silver layers. Such silver layers exhibit particularly advantageous reflection properties combined with high transmission in the visible spectral range. The thickness of a silver layer is preferably from 1 nm to 50 nm, and particularly preferably from 5 nm to 25 nm. Within this range for the thickness of the silver layer, advantageously high transmission in the visible spectral range and particularly advantageous electrical conductivity are achieved.

[0038] Particularly preferably, the IR-reflecting coating comprises at least two silver layers, and more preferably at least three silver layers. Preferably, at least one dielectric layer is arranged between each pair of adjacent silver layers of the coating. A dielectric layer contains at least one layer of a dielectric material, for example, a nitride such as silicon nitride or an oxide such as aluminum oxide. Dielectric layers can also comprise several layers, for example, layers of a dielectric material, smoothing layers, matching layers, blocking layers, and / or antireflection layers. The thickness of a dielectric layer is, for example, from 10 nm to 200 nm. This achieves, for example, the technical advantage that infrared light can be effectively blocked.The blocking of infrared light is achieved particularly well when the infrared protective layer comprises at least two silver layers, more preferably three silver layers, and in particular exactly three silver layers.

[0039] In a particularly preferred embodiment of the invention, the IR-reflective coating is applied to the first surface of the optical waveguide, or, if the optical waveguide itself is a coating on a disk, arranged between the optical waveguide and the coated disk. The IR-reflective coating has a lower refractive index than the optical waveguide. The IR-reflective coating preferably has a refractive index of less than 1.5, more preferably less than 1.4. This effectively blocks the IR radiation and simultaneously enhances the effect of total internal reflection, causing the IR radiation to remain coupled within the optical waveguide for a longer period and to be more likely to strike a water-contaminated area on the second surface of the optical waveguide.

[0040] In a further preferred embodiment, the at least one radiation source can be functionally connected to at least one sensor, in particular a temperature and / or humidity detector. This can advantageously be used for automated defrosting or removal of condensed moisture. Additionally, it can also prevent the icing of the refrigerator glass or the formation of condensate and the associated obstruction of view. The sensor is preferably attached to the optical fiber or, if the optical fiber is a coating on a glass pane, to the glass pane itself.

[0041] In a further preferred embodiment of the invention, the at least one radiation source is arranged on at least one section of a circumferential edge surface of the optical waveguide or the edge surface of the disk on which the optical waveguide is mounted. The radiation source is, for example, associated with at least one side edge surface or attached to two opposite side edge surfaces and / or to the top edge and / or the bottom edge, for example, by being glued or arranged in a socket attached to the disk. The IR radiation is then coupled into the optical waveguide via one, two, three, or four, or more (for example, all) edge surfaces. It can be advantageous to irradiate the optical waveguide from one or more sides with several radiation sources in order to increase the heating effect accordingly. In particular, the radiation source is arranged at the bottom edge.This is a good option because this arrangement is usually the least visually obtrusive. The bottom edge of the refrigerator's glass is typically concealed by components of the refrigerator and is also not at eye level for the user.

[0042] In a further embodiment of the invention, the at least one radiation source is arranged in a recess of the optical waveguide. If the optical waveguide is a coating on a disk, the disk preferably also has a recess in which the radiation source is arranged. The radiation source is arranged in the recess such that it can couple IR radiation into the optical waveguide, which then serves either to remove condensed moisture or to defrost. The optical waveguide thus has a recess. This recess is preferably a hole, i.e., a feedthrough, which extends between the first and second surfaces of the optical waveguide.However, if the optical fiber is a disk, the recess can alternatively be a depression similar to a blind hole (a sack-like depression) extending into the disk from the second or first surface without reaching the opposite main surface, thus avoiding the formation of a through-hole. The recess can be created, for example, by mechanical drilling or laser processing in the optical fiber. The recess is preferably round, but can, in principle, have any desired shape, including polygonal shapes. This refers to the base of the recess, in the plane of the at least one surface of the optical fiber through which the recess is introduced. The recess as a whole has the shape of a cylinder, preferably a vertical cylinder.The cylinder is preferably a circular cylinder (circular base), but can also have any other base shape, for example an elliptical base (elliptical cylinder) or a polygonal base (prism).

[0043] The recess, whether a feedthrough or a depression, is bounded by a circumferential edge surface that extends between the main faces of the optical fiber. If the optical fiber is applied as a coating to a disk, and both the optical fiber and the disk have a recess, then the coated disk also has a circumferential edge surface. In the case of a feedthrough, this is the only boundary surface of the recess. In the case of a sac-like depression, there is an additional boundary surface that faces the main face of the optical fiber to which the depression does not extend, and which effectively forms the bottom of the sac.If the optical fiber is formed as a coating on a disk, a recess in the form of a sack-like depression means that the optical fiber has a passage through it, and the disk on which it is applied has a sack-like depression, which was created, for example, by means of a blind hole. The passage through the optical fiber and the sack-like depression in the disk are essentially congruent with each other.

[0044] The radiation source is arranged on the edge surface of the recess in the optical fiber / coated disk, preferably attached, in particular glued, or arranged in a socket fixed to the recess. The IR radiation is then coupled into the optical fiber via the inner edge surface and, due to the lower refractive index of water, selectively coupled out of the interior of the optical fiber in the presence of ice or at points of condensation.

[0045] In another embodiment, the optical waveguide is designed as a disk, and the at least one radiation source is preferably arranged in an edge region of the optical waveguide on the second surface. In particular, a further radiation source is preferably arranged in an edge region of the optical waveguide on the first surface. In the edge region, the radiation sources are less visually conspicuous and can be easily concealed by components of the cooling device. The use of two radiation sources can be advantageous to improve the radiation intensity.

[0046] In one embodiment, the radiation source is applied to the second surface of the optical fiber, while the first surface of the optical fiber has an IR mirror layer, i.e., a reflective coating for the infrared range, which is positioned overlapping the at least one radiation source when viewed through the refrigerator glazing. In this way, the optical fiber is irradiated with IR radiation via the second surface. The at least one radiation source is attached to the second surface of the optical fiber, for example, by bonding it with an optically clear adhesive (OCA). This couples the IR radiation into the optical fiber via reflection from the IR mirror layer. This reduces the complexity of the refrigerator glazing, as the radiation source does not need to be positioned on the edges of the optical fiber.The IR mirror layer can alternatively be applied to the second surface of the optical waveguide. In this case, the radiation source is then located on or applied to the first surface of the optical waveguide. When viewed through the refrigerator glazing, the IR mirror layer and the radiation source are preferably arranged overlapping each other. The IR mirror layer is preferably designed as an IR-radiation-reflecting prismatic film.

[0047] An optically clear adhesive is preferably a material containing or made from polyacrylate compounds (e.g., polyacrylate or polymethyl acrylate) or silicone. For the purposes of this invention, "clear" means that the adhesive is transparent.

[0048] When an IR mirror layer is used for coupling, the IR radiation from the radiation source is (at least partially) reflected back towards the optical fiber by the IR mirror layer, where it is coupled into the optical fiber via coupling using the principle of total internal reflection. This helps to distribute the IR radiation within the optical fiber and direct it to the areas to be heated, i.e., icy or condensation-covered areas of the refrigerator's glass.

[0049] IR mirror coatings are known per se and can be designed, for example, as a silver-containing coating or as a layer of an electrically conductive oxide (transparent conductive oxide, TCO), such as indium tin oxide (ITO). Alternatively, the IR mirror coating can also be arranged in the form of a coated thermoplastic film, for example made of polyethylene terephthalate (PET), on the optical fiber or between the optical fiber (which is designed as a coating) and a disk. In this embodiment, the radiation source(s) is / are preferably arranged in a region of the optical fiber that, in its installed position, cannot be seen from the external environment (for example, concealed by seals or other components of the cooling device).The IR mirror layer is preferably an IR-radiation-reflecting prism film, which is preferably additionally coated with an IR-reflective coating based on an electrically conductive oxide. In particular, the IR mirror layer is a microprism film, which may also be coated with an IR-reflective coating based on an electrically conductive oxide. If the prism film or microprism film is coated with an IR-radiation-reflecting coating, it can also be transparent to IR radiation, so that the IR radiation is only reflected by the IR-radiation-reflecting coating. The inclined surfaces of the prism film cause the IR rays to be reflected at a particularly advantageous angle by the IR mirror layer, so that they strike the optical waveguide at an angle of incidence at which a particularly high proportion of the IR radiation can be coupled in.

[0050] Mixtures and combinations of the aforementioned configurations are also possible. For example, the optical fiber can be irradiated and heated by a radiation source at its lower edge and additionally by another radiation source on its secondary surface. Similarly, a radiation source can be arranged in a recess of the optical fiber / coated disk, and an additional radiation source can be attached to an edge. These are only examples and are not exhaustive.

[0051] In a further embodiment of the invention, the refrigerator glazing comprises at least one additional radiation source, preferably at least two additional radiation sources, which are suitably arranged to couple IR radiation into the optical waveguide. The radiation sources are preferably switchable and operable independently of one another. Thus, the associated radiation sources can be controlled independently of one another, allowing the heating power or intensity to be selectively adjusted.

[0052] In a preferred embodiment, the radiation source is arranged in an opaque area, preferably an edge region, of the refrigerator glazing, which completely covers the radiation source when viewed through the glazing. This allows the radiation sources to be optically concealed from the outside. To prevent the coupling of the IR radiation into the optical waveguide by the opaque area, a small opening in the opaque area—i.e., a small, non-opaque region—can be provided in the IR beam path.

[0053] In the context of the invention, “complete occlusion / overlapping of an element A with an element B” means that the orthonormal projection of element A to the plane of element B is completely arranged within element B.

[0054] Refractive indices are generally specified within the scope of the present invention with reference to a wavelength of 1500 nm. Methods for determining refractive indices are known to those skilled in the art. The refractive indices specified within the scope of the invention can, for example, be determined by ellipsometry, using commercially available ellipsometers. Unless otherwise specified, the specification of layer thicknesses or thicknesses refers to the geometric thickness of a layer.

[0055] If the optical waveguide is designed as a disk, it can also be provided with an emissivity-reducing coating on its first or second surface. If the optical waveguide itself is designed as a coating and applied to a disk, the disk coated with the optical waveguide can have an emissivity-reducing coating. Preferably, such a disk has the emissivity-reducing coating on its first surface. The emissivity-reducing coating can also be applied to the inner disk, the outer disk, or any intermediate disk, and if applied to the intermediate or outer disk, it is preferably applied to their second surface. If the emissivity-reducing coating is applied to the inner disk, it is preferably applied to its first surface.

[0056] The emissivity-reducing coating is a heat-radiation-reflecting coating. Such a coating is also frequently referred to as a low-E coating or low-emissivity coating. Its function is to prevent heat radiation from entering the interior (thermal radiation from the pane itself) and also from radiating heat out of the interior. For the purposes of this invention, emissivity is understood to be the normal emissivity at 283 K according to standard EN 12898.

[0057] The emissivity-reducing coating is preferably a sequence of thin layers (layer structure, layer stack). One layer is an electrically conductive layer, whereas the optical properties (transmission and reflectivity) of the coating are largely determined by the other layers and can therefore be specifically adjusted through their design. So-called anti-reflective coatings, which have a low refractive index of preferably at most 1.8 and particularly preferably at most 1.6, have a particularly significant influence in this context. These anti-reflective coatings can increase the transmission through the disk and reduce the reflectivity, especially due to interference effects. The effect depends critically on the refractive index and the layer thickness.

[0058] The refrigerator glazing can be flat or curved in one or more directions; however, it is preferably not curved, i.e., essentially flat. Preferably, the refrigerator glazing also has a substantially rectangular shape in plan view, with the corners possibly being rounded. Thus, "essentially rectangular" excludes trapezoidal glazing.

[0059] The invention also extends to a cooling device comprising the cooling device glazing according to the invention as described above.

[0060] The cooling appliance can be, for example, a refrigerator, a freezer, a chest freezer, or a freezer box. Preferably, the cooling appliance is a refrigerator or a freezer box.

[0061] The refrigerator glazing is preferably arranged within the refrigerator in such a way that it separates the interior of the refrigerator from the external environment. The refrigerator glazing should allow a view into the refrigerator without having to open it. It is therefore preferably a component of the refrigerator that is visible from the external environment when the refrigerator is closed.

[0062] In a particularly preferred embodiment of the invention, the cooling appliance also comprises at least one cooling appliance door. For the purposes of this invention, a cooling appliance door is defined as a movable component designed for opening and closing the cooling appliance. The cooling appliance door can therefore be a hinged door, a pivot door, a sliding door, a swing-sliding door, etc. Different types of cooling appliance doors are known to those skilled in the art, so a detailed description is unnecessary here.

[0063] The refrigerator door preferably includes the refrigerator glazing according to the invention. The refrigerator glazing is thus a component of the refrigerator door. Particularly preferably, the refrigerator glazing is arranged as a component of the refrigerator door such that the second surface of the optical fiber is the surface exposed to the interior of the refrigerator. This is advantageous because, when the door is opened, the inside of the refrigerator door comes into contact with the external environment, and water subsequently forms on the cooled inside surface through condensation, which can then be removed according to the invention.

[0064] In a further preferred embodiment of the invention, the cooling device also comprises a humidity detector for detecting water on the first and / or second surface of the optical fiber and a control unit. The humidity detector is preferably configured to send a signal, referred to here for simplicity as signal A, to the control unit when water is present on the first and / or second surface of the optical fiber. In this case, the control unit is configured to electronically control the radiation source, at least upon receiving signal A, so that the radiation source emits IR radiation which is coupled into the optical fiber. This offers the advantage that the radiation source is only in operation when water is deposited on the optical fiber, thereby significantly reducing the energy consumption of the radiation source.The humidity detector is preferably attached to the refrigerator glazing so that it can effectively detect water condensed on the first surface and / or the second surface.

[0065] In a further particularly preferred embodiment of the invention, the cooling unit comprises at least one cooling unit door as described above, a motion sensor, and a control unit. The motion sensor is configured to send a signal, referred to here for simplicity as signal B, to the control unit when the cooling unit door is open. The control unit is configured to electronically control the radiation source, at least upon receiving signal B, so that the radiation source emits IR radiation, which is coupled into the optical fiber. This achieves the advantage that the radiation source always emits IR radiation when the door is open and thus typically comes into contact with the ambient humidity. Motion sensors are also significantly less expensive than humidity detectors and are less prone to failure.The motion sensor is preferably attached at least to the refrigerator door, for example, to the refrigerator glass. Particularly preferably, part of the motion sensor is attached to the refrigerator door stop and another part to the refrigerator door itself. The two parts of the motion sensor are in contact with each other when the refrigerator door is closed and are not in contact with each other when the refrigerator door is open. In the context of the invention, "in contact with each other" means, for example, that an electronic connection exists between the two parts or that the two parts of the motion sensor are in direct contact. "Not in contact" in this context means that the parts are not in contact with each other.

[0066] Preferably, the cooling device has both a humidity detector and a motion sensor, whereby signal A and signal B, which is emitted once by the humidity detector and once by the motion sensor, can also be identical.

[0067] The control unit and the humidity detector and / or the motion sensor can be connected via cables or wirelessly. Similarly, the control unit and the at least one radiation source can be connected via cables or wirelessly.

[0068] In the context of the invention, "closed state" means that the refrigerator door essentially completely separates the interior of the refrigerator from the external environment. "Open state" means that the refrigerator door does not completely close the refrigerator opening, i.e., the interior of the refrigerator is not completely separated from the external environment.

[0069] The refrigerator glazing, as described above in various embodiments, can be manufactured by a process that includes at least: (A) the radiation source is arranged in such a way as to the optical waveguide, (B) that the IR radiation is coupled into the optical waveguide.

[0070] In other words: Arrange the radiation source to the optical waveguide so that the IR radiation emitted by the radiation source can be coupled into the optical waveguide.

[0071] Furthermore, the cooling appliance glazing can be used in cooling appliances such as refrigerators, freezers, and / or chest freezers.

[0072] The various embodiments of the invention can be implemented individually or in any combination. In particular, the features mentioned above and to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, unless they are explicitly described as possible only as alternatives to one another without departing from the scope of the present invention.

[0073] The invention is explained in more detail below with reference to exemplary embodiments, with reference to the accompanying figures. These show, in a simplified representation not to scale: Fig. 1a An embodiment of the cooling device according to the invention in a side view, Fig. 1b Top view of an embodiment of the cooling unit glazing according to the invention of the cooling unit made of Fig. 1a, Fig. 1c a cross-sectional view of the refrigerator glazing made of Fig. 1b and a humidity detector of the cooling unit Fig. 1a, Fig. 2-5 further designs of the refrigerator glazing in cross-sectional view, Fig. 6. An absorption spectrum of water (liquid state).

[0074] The Fig. 1a, Fig. 1b and Fig. Figures 1c show different aspects of an embodiment of the cooling device 102 according to the invention and an embodiment of the cooling device glazing 100 according to the invention. Fig. Figure 1a shows the cooling unit 102 in a side view looking towards the cooling unit door 101. Fig. Figure 1b shows the refrigerator glazing 100 in a top view, the glazing 100 having an area moistened with water 10. Fig. 1c shows the refrigerator glazing 100 from Fig. 1b in cross-section and also the humidity detector 13 of the refrigerator door 101 in cross-section. The humidity detector 13 is electrically connected to a control unit 14 by means of a connecting element, for example a cable. The cross-section of the Fig. 1c is marked by a dashed line XX' in Fig. 1b indicated.

[0075] The refrigerator glazing 100 is part of the refrigerator door 101 and allows a view from an external environment 9 into the refrigerator interior 8. The refrigerator door 101 comprises a frame in the center of which the refrigerator glazing 100 is set. A humidity detector 13 is arranged centrally on the upper part of the frame of the refrigerator door 101, for example, by gluing or screwing it on. In its installed position, the upper part of the frame is directly adjacent to the top edge of the glazing. In the present embodiment, the refrigerator glazing 100 is flat, although it is also possible for it to be curved. Preferably, however, the refrigerator glazing 100 is flat.

[0076] The refrigerator glazing 100 comprises an optical fiber 1 and a radiation source 2. The optical fiber 1 is designed as a glass pane. The glass pane is made, for example, of soda-lime glass. The optical fiber 1 has, for example, a thickness of 3.5 mm. The refrigerator glazing 100 also comprises an outer pane and a spacer, wherein the optical fiber 1 and the outer pane are connected to each other via the spacer. The refrigerator glazing 100 according to the invention is therefore a multi-pane glazing with two panes. For the sake of simplicity, the outer pane and the spacer are not shown in Fig. Figure 1c shows the following. In the installed position, the upward-pointing edge is referred to as the top edge O. The upper part of the frame of the refrigerator door 101 is directly adjacent to the top edge O of the refrigerator glazing 100 in the installed position. The downward-pointing edge of the optical fiber 1 in the installed position is referred to as the bottom edge U. The edges running between these are referred to as side edges S1 and S2. The optical fiber 1 also has a first surface I, which faces the external environment 9, and a second surface II, which faces the interior of the refrigerator 8. A water stain 10 is arranged on the second surface II, for example, as water droplets that have condensed on the second surface II.

[0077] An IR radiation source 2, which, for example, comprises at least one LED with a wavelength in the wavelength range of λ = 1.3 µm to 3.5 µm, is arranged at the lower edge U of the optical waveguide 1. The radiation source 2 can, for example, comprise an Er:YAG diode with a wavelength of approximately 2960 nm. This wavelength corresponds to the frequency and wavelength range in which water molecules exhibit the highest absorption coefficient for IR radiation 3 (see Fig. 6) At the same time, the transmission of glass in this IR radiation range <3.5 µm is particularly high, with a transmittance of approximately 85%, and only a small portion is absorbed. The at least one LED can, for example, be glued on or arranged in a socket attached to the optical fiber 1. In this configuration, the radiation source 2 is ribbon-shaped and / or arranged in a ribbon-like form. The arrows indicate, by way of example and schematically, the direction of radiation of the IR radiation 3. The IR radiation 3 is coupled into the optical fiber 1 via the edge surface at the lower edge U. Furthermore, the radiation source 2 is functionally connected to a control unit 14, for example, by means of a cable.

[0078] Glass can conduct IR radiation 3 when it is coupled into the glass. In areas where moisture 10 has formed on the optical waveguide 1, i.e., where the optical waveguide 1 is covered with water droplets 10 or ice crystals, for example, the IR radiation 3 is selectively coupled out, since water has a lower refractive index and is therefore an optically less dense medium than the glass of the optical waveguide 1. The IR radiation 3 is absorbed by the water molecules, which are heated by the excitation of the radiation 3 and thus evaporate. A particular advantage of the invention is that IR radiation 3 is used, which is located in the frequency range in which water molecules have the highest absorption coefficients, thus enabling a very selective heating effect. This contributes to achieving a particularly energy-efficient heating effect.

[0079] Energy efficiency is an extremely important criterion for future product development. Advantageously, according to the invention, the heating effect does not depend on the heating of the refrigerator glazing 100 itself, but is achieved selectively by exciting the water molecules through IR radiation 3. In contrast, with conventional heating of refrigerator glazing, for example by means of heating layers, a particularly energy-intensive heating effort is required to counteract the cooling of the refrigerator 102. Therefore, with the glazing according to the invention, the heating effect occurs much faster than with conventional heating devices, and additionally, there is no heat loss due to convection and the large surface area of ​​the glazing 100.By firmly attaching the radiation source 2 to the lower edge U of the optical fiber 1, preferably by means of adhesive bonding, the refrigerator glazing 100 can also be movable, for example, opened and closed, without the IR radiation 3 being coupled into the optical fiber 1. The use of a humidity detector 13 can further increase energy efficiency.

[0080] The moisture detector 13 is connected to the radiation source 2 via a control unit 14. The moisture detector 13 is suitably configured and positioned to detect water 10 on the second surface II of the optical fiber 1. If the moisture detector 13 detects water 10 on the second surface II, it sends a signal to the control unit 14. The control unit 14 is electronically connected to the radiation source 2 and, when the control unit 14 receives a signal from the moisture detector 13, it instructs the radiation source 2 to emit IR radiation 3. It is understood that the control unit 14 does not instruct the radiation source 2 to emit IR radiation 3 if the moisture detector 13 does not detect water 10 and therefore does not send a signal to the control unit 14.The cooling unit 102 can additionally or alternatively be connected to a motion sensor, which, similar to the humidity detector 13, is connected to the control unit 14 (not shown here). The motion sensor can, for example, send a signal to the control unit 14 when the cooling unit door 101 is open, and no signal to the control unit 14 when the cooling unit door 101 is closed. Parallel to the variant with the humidity detector 13, the control unit 14, upon receiving a signal from the motion sensor, instructs the radiation source 2 to emit IR radiation 3.

[0081] The in the Fig. The variants of the refrigerator glazing shown in sections 2 to 5 essentially correspond to the variant of the Fig. 1a, Fig. 1b and Fig. 1c, so only the differences will be discussed here, and otherwise the description will be based on the Fig. 1a, Fig. 1b and Fig. 1c is referred to. Also the refrigerator glazing 100 in the Fig. 2 to 4 have an outer pane and a spacer arranged between the optical fiber 1 and the outer pane, so that the glazing units are 100 multiple glazing units (outer pane and spacer are not in the Fig. 2 to 4 shown). In the design according to Fig. 5 are the outer disc 11 and the spacer 7 in the Fig. 5 shown. In the Fig. Figures 2 to 5 do not show humidity detectors 13, motion sensors, or control units 14. However, these can optionally be part of the refrigerator glazing 100 or part of a refrigerator 102, which is one of the components shown in the Fig. The range of refrigerator glazing shown includes 2 to 5 variants.

[0082] In Fig. In addition to the radiation source 2 at the lower edge U of the optical waveguide 1, another radiation source 2 is arranged at the upper edge O of the optical waveguide 1, for example, bonded to the optical waveguide 1. The additional radiation source 2 couples IR radiation 3 into the optical waveguide 1 via the upper edge O. In this way, the IR radiation 3 is distributed more evenly over the entire surface of the optical waveguide 1 and is coupled out at water droplets 10 with higher intensity. An IR-reflective coating 4 is applied, for example, to the entire surface of the first surface I of the optical waveguide 1. The IR-reflective coating 4 comprises, for example, one or more silver layers. The coating 4 largely prevents IR radiation 3 from being coupled out at the first surface I of the optical waveguide 1 and thus from escaping into the external environment 9.

[0083] In Fig. In this case, the optical waveguide 1 is not formed as a glass pane, but as a layer based on silicon nitride. The optical waveguide 1 is applied as a coating to a (second) surface ii of a pane 6 facing the interior of the cooling unit 8. The silicon nitride coating is transparent and suitable for guiding IR radiation 3 by utilizing total internal reflection. The pane 6 is, for example, a soda-lime glass pane with a thickness of 3.5 mm. The optical waveguide 1 has, for example, a layer thickness of 1 µm. The radiation source 2 is arranged on the (first) surface i of the glass pane 6 facing the external environment 9. The radiation source 2 is located in an edge region of the pane 6 adjacent to the lower edge U of the pane 6. The outer pane is connected to the first surface i of the glass pane 6 via the spacer (not shown here).The first surface i of disk 6 is therefore not exposed to the external environment.

[0084] An IR mirror layer 5 is applied to the second surface II of the optical waveguide 1, the one facing away from the disk 6. The IR mirror layer 5 is, for example, a microprismatic film bonded to the optical waveguide 1 using an optically clear adhesive. During operation, the radiation source 2 emits IR radiation 3 perpendicular to the disk 6. The IR radiation 3 enters the disk 6 via the first surface i and transmits through it until it exits the disk 6 via the second surface ii and enters the optical waveguide 1 via the first surface I. The IR radiation 3 transmits through the optical waveguide 1 and exits at the second surface II of the optical waveguide 1. The IR radiation 3 then strikes the IR mirror layer 5 and is reflected back to the optical waveguide 1.Here, the IR radiation 3 strikes the optical waveguide 1 at such an angle that it can be at least partially coupled into the optical waveguide 1. Due to the inclined surfaces of the microprismatic film, the IR radiation 3 is reflected onto the optical waveguide 1 at a suitable angle.

[0085] In Fig. In the optical waveguide 1, a silicon nitride-based coating is applied to the second surface ii of a disk 6. The disk 6 has a recess 12 in the form of a hole. The hole is, for example, cylindrical. It can be created, for example, by drilling a hole in the glass. The radiation source 2 is arranged within the opening. The radiation source 2 is positioned such that it can couple the IR radiation 3 directly via the edge region of the optical waveguide 1. The recess 12 is located in an edge region of the disk 6 adjacent to the lower edge U. The outer disk is connected to the first surface i of the glass disk 6 via the spacer (not shown here). The first surface i of the disk 6 is therefore not exposed to the external environment.

[0086] In Fig. 5. The optical waveguide 1 has an IR-reflective coating 4 on its first surface I. The IR-reflective coating 4 extends over the entire first surface I of the optical waveguide 1, i.e., it is applied across the entire surface. The IR-reflective coating 4 comprises, for example, one or more silver layers. The coating 4 largely prevents IR radiation 3 from being coupled out at the first surface I of the optical waveguide 1 and thus from escaping into the external environment 9. The optical waveguide 1 is also connected to an outer disk 11 at its edge via a spacer 7. The spacer 7 is frame-shaped and arranged at the edge between the optical waveguide 1 and the outer disk 11 to keep them essentially plane-parallel at a defined distance from each other. The spacer is made of, for example, aluminum.It is preferably in contact with the optical waveguide 1, or the IR-reflective coating 4 applied to the optical waveguide 1, and the outer disk 11 via a sealant. For example, an outer sealant based on silicone is filled into the outer, externally open space between the disks. The inner space between the disks, which is bounded and enclosed by the optical waveguide 1, the outer disk 11, and the spacer, is filled with argon, for example. The outer disk 11 is, for example, a soda-lime glass disk with a thickness of 3.5 mm. The outer disk 11 has a second surface iv exposed to the external environment 9 and a first surface iii facing the space between the optical waveguide 1 and the outer disk 11.

[0087] Fig.Figure 6 shows an absorption spectrum of water in the liquid state. The diagram shows that water molecules, for example, exhibit a particularly high absorption coefficient at a wavelength of approximately 3 µm. In a preferred embodiment, a radiation source in the IR wavelength range of λ = 2.5 µm to λ = 3.3 µm, and particularly preferably from λ = 2.9 µm to λ = 3.1 µm, is therefore used for the refrigerator glazing, since in this preferred wavelength range the absorption and excitation of the water molecules, and thus the resulting heating and evaporation, are particularly high. Preferably, the optical waveguide simultaneously exhibits a transmission in the wavelength range from λ = 2.9 µm to λ = 3.1 µm of over 70%, particularly at approximately λ = 3.0 µm of approximately 85%, so that the radiant energy can be used efficiently for de-icing and evaporation of water in the corresponding areas. Reference symbol list: 1 optical fiber 2 radiation source 3 IR radiation 4 IR-reflective coating 5 IR mirror layer 6 discs 7 spacers 8 Refrigerator interior 9 external environment 10 Water 11 outer disc 12 Exclusion 13 Moisture detector 14 Control unit 100 Refrigerator glazing 101 Refrigerator door 102 Cooling unit i first surface of the disk 6 ii second surface of the disk 6 iii first surface of the outer disk 11 iv second surface of the outer disk 11 I first surface of the optical waveguide 1 II second surface of the optical waveguide 1 S1 first side edge S2 second side edge O top edge U lower edge XX' Intersection line QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 2454657A1

[0004] EP 1499218B1

[0004] DE 102017201190A1

[0006] WO 2023073593A1

[0007] US 2017013679A1

[0008] WO 2017137111A1

[0008]

Claims

[1] Refrigerator glazing (100), comprising - at least one optical waveguide (1) for guiding radiation (3) in the IR wavelength range with a first surface (I) and a second surface (II), - at least one radiation source (2) for radiation (3) in the IR wavelength range from λ = 1.3 µm to 3.5 µm, - an outer disc (11) and - a spacer (7) which is arranged between the optical waveguide (1) and the outer disk (11), wherein the radiation source (2) is arranged to the optical waveguide (1) in such a way that the radiation (3) emitted by the radiation source (2) can be coupled into the optical waveguide (1). [2] Refrigerator glazing (100) according to claim 1, wherein the radiation source (2) comprises at least one LED, OLED and / or a laser, preferably at least one LED. [3] Refrigerator glazing (100) according to claim 1 or 2, wherein the radiation source (2) can emit radiation (3) in the IR wavelength range from λ = 2.5 µm to λ = 3.3 µm, preferably from λ = 2.6 µm to λ = 2.9 µm. [4] Refrigerator glazing (100) according to one of claims 1 to 3, wherein the optical waveguide (1) is designed as a disk and the second surface (II) of the optical waveguide (1) is provided to be a surface exposed to the interior of the refrigerator (8), and the spacer (7) connects the outer disk (11) and the optical waveguide (1). [5] Refrigerator glazing (100) according to one of claims 1 to 4, wherein the optical waveguide (1) is a glass sheet made of soda-lime glass, borosilicate glass, quartz glass or aluminosilicate glass. [6] Refrigerator glazing (100) according to claim 4 or 5, wherein an IR-reflecting coating (4) is applied to the first surface (I) of the optical waveguide (1) and extends over at least 80% of the area of ​​the optical waveguide (1). [7] Refrigerator glazing (100) according to claim 6, wherein the IR-reflecting coating (4) comprises at least one metallic layer. [8] Refrigerator glazing (100) according to one of claims 1 to 3, wherein the optical waveguide (1) is applied as a coating to a surface (ii) of a disk (6) and contains, preferably consists of, silicon nitride and / or titanium dioxide. [9] Refrigerator glazing (100) according to one of claims 1 to 8, wherein the radiation source (2) is arranged on at least one section of a circumferential edge surface (S1, S2, O, U) of the optical waveguide (1). [10] Refrigerator glazing (100) according to one of claims 1 to 8, wherein an IR radiation-reflecting prism foil (5) is applied to the first surface (I) or the second surface (II) of the optical waveguide (1) and wherein the radiation source (2) is arranged to the IR radiation-reflecting prism foil (5) such that the emitted radiation (3) can be coupled into the optical waveguide (1) by means of reflection at the IR radiation-reflecting prism foil (5). [11] Refrigerator glazing (100) according to one of claims 1 to 8, wherein the radiation source (2) is arranged in a recess (12) of the optical waveguide (1). [12] Cooling appliance (102) comprising a cooling appliance glazing (100) according to any one of claims 1 to 11. [13] Cooling device (102) according to claim 12, further comprising - a refrigerator door (101) which has the refrigerator glazing (100). [14] Cooling device (102) according to claim 12 or 13, further comprising - a moisture detector (13) for detecting water (10) on the first surface (I) and / or the second surface (II) of the optical waveguide (1) and - a control unit (14), wherein the moisture detector (13) is configured to send a signal A to the control unit (14) when water (10) is present on the first surface (I) and / or the second surface (II) of the optical fiber (1), wherein the control unit (14) is configured such that, at least upon receipt of signal A, it electronically controls the radiation source (2) so that the radiation source (2) emits radiation (3) which is coupled into the optical waveguide (1). [15] Cooling device (102) according to claim 13 or 14, further comprising - a motion sensor and - a control unit (14), wherein the motion sensor is configured to send a signal B to the control unit (14) when the refrigerator door (101) is opened, wherein the control unit (14) is configured such that, at least upon receipt of signal B, it electronically controls the radiation source (2) so that the radiation source (2) emits radiation (3) which is coupled into the optical waveguide (1).

Images