Vehicle with exterior device, vehicle pane and IR radiation source

Abstract

The invention relates to a vehicle (100) comprising at least one vehicle pane (1) with an exterior-side surface (I), which is exposed to the external environment (9), and at least one exterior device (2) mounted outside of the vehicle interior (8). At least one radiation source (3) for IR radiation (4) in the IR wavelength range of 1.3 µm to 3.5 µm is mounted on the exterior device (2), the radiation source (3) is positioned relative to the vehicle pane (1) in such a way that the radiation source (3) irradiates the entire exterior-side surface (I) of the vehicle pane (1) or a region (P) thereof during operation, and between the radiation source (3) and the vehicle pane (1) is a scattering element (13) for scattering the IR radiation (4).

Description

[0001] Vehicle with external device, vehicle window and IR radiation source

[0002] The invention relates to a vehicle with an exterior device, a vehicle window and an IR radiation source, as well as a method for removing moisture from the vehicle window of the vehicle.

[0003] One challenge when driving is heating vehicle windows to prevent icing or fogging, which obstructs visibility. The window is typically heated using heated air that is blown onto the window via inlets. This type of heating is collectively referred to as the Heating, Ventilation, and Air Conditioning (HVAC) method. In addition to the enormous energy consumption, the inlets through which the hot air is transported and blown onto the window require a lot of space. Furthermore, the outlet nozzles must be mounted in a specific geometric relationship to the window, which in turn significantly limits the design and construction freedom.

[0004] Heated vehicle windows are well known. They are used primarily as heated windshields in motor vehicles and offer the possibility of conveniently removing ice or condensed moisture from the windshield by heating it. They feature transparent, electrically conductive coatings, particularly silver coatings. The coatings are electrically connected so that a current can be passed through them. This heats up the coating, which is responsible for the heating effect. For example, see WO2013 / 104438A1.

[0005] One problem with electrically conductive coatings is their often high sheet resistance, which, especially for large-sized windows or long current paths, requires a high operating voltage, which is certainly higher than the usual on-board voltages in vehicles. WO 2013 / 104439 A1 and EP 2803246 B1 disclose an electrically conductive coating for heating a window. It consists of different layers that can be used to slightly reduce the sheet resistance. Furthermore, the heat and thus energy loss due to convection across the usually large window surfaces is very high.

[0006] Another disadvantage of heatable coatings is that silver coatings, for example, are impermeable to high-frequency radiation. This impairs, for example, the reception of mobile phone signals, communication with cloud servers (the "Internet of Things"), and similar functions. This can cause problems, especially in the case of electric vehicles. Some vehicle manufacturers, especially electric vehicle manufacturers, therefore reject the use of silver-containing coatings.

[0007] A further challenge for electrically conductive coatings, which are often multi-layered, for heating laminated panes is compliance with required standards, for example with regard to light transmission and color neutrality.

[0008] If the vehicle window is constructed as a laminated pane, as is the case with windshields, for example, thermal radiation can also be used to prevent fogging or icing. JP2013001611A discloses a laminated pane with an intermediate layer that absorbs IR radiation. Irradiating the laminated pane with IR radiation heats it up, thereby reducing fogging or icing.

[0009] Another major disadvantage of these solutions for removing moisture from a vehicle's windshield is that heating by convection or conduction requires the windshield to reach its temperature. The windshield must be heated until a suitable temperature is reached to remove fog and frost. This process is time-consuming and energy-inefficient.

[0010] FR960125A and US20110067726A1 show composite panes designed as windshields with IR radiation sources. If water droplets or frost are on the windshield, they can be irradiated by the IR radiation source located in the vehicle interior, causing any watery films on the windshield to evaporate. A disadvantage of this solution is that the panes absorb some of the IR radiation, reducing efficiency. Further disadvantages are that the radiation sources must be mounted in a specific geometric relationship to the pane, which in turn significantly limits the design and construction freedom in the vehicle interior. Finally, there is a risk that vehicle occupants could enter the radiation path of the radiation source, which can lead to irritation and, in the worst case, burns.DE202023103844U1 discloses a heatable composite pane comprising an outer pane and an inner pane, which are connected to one another via a thermoplastic intermediate layer, and at least one heating device. The heating device is a transparent heating layer made of photothermal material having an absorption of greater than 70%, preferably greater than 85%, in the IR wavelength range > 0.8 pm, preferably > 0.9 pm, particularly preferably > 1.0 pm. The wavelength range of the radiation source is expediently matched to the photothermal material used for the heating device, i.e., the wavelength range of the photothermal material for the maximum possible IR absorption.

[0011] There is a need for vehicles whose windows can be efficiently and quickly freed of moisture without compromising the safety of the vehicle occupants or restricting the space required in the vehicle interior. The present invention is based on the object of providing such a vehicle and a method for removing moisture in such a vehicle.

[0012] The object of the present invention is achieved by a vehicle according to claim 1 and a method according to claim 13. Preferred embodiments are evident from the subclaims.

[0013] According to the invention, the vehicle comprises at least one vehicle window (also called the first vehicle window) with an outer surface exposed to the external environment, and at least one external device mounted outside the vehicle interior. "Exposed to the external environment" in the sense of the invention means that the surface is directly adjacent to the external environment, so that the moisture contained in the air can condense on the surface of the vehicle. The outer surface of the vehicle window can have a functional coating or be coating-free. In other words, the outer surface can be formed by the uncoated surface of the vehicle window or a coating applied to the surface of the vehicle window.For the purposes of the invention, "external device outside the vehicle interior" refers to a device located on the outside of the vehicle, for example, on the body or outer skin of the vehicle, and thus also exposed to the external environment. The external device may well form an interior space separated from the external environment. The external device is preferably a side mirror or a side camera of a vehicle. It is also possible for the external device to have both a side mirror and a side camera.

[0014] According to the invention, at least one radiation source is attached to the external device. The radiation source is designed such that it can emit IR radiation in the IR wavelength range from 1.3 pm to 3.5 pm. The radiation source is arranged relative to the vehicle window such that, during operation, it irradiates at least the outer surface of the vehicle window completely or in regions, i.e. in one region. The radiation source is preferably arranged such that it irradiates at least 30%, particularly preferably 50%, very particularly preferably at least 70% of the outer surface. In particular, the radiation source is arranged such that it irradiates at least the region of the outer surface through which at least one vehicle occupant, in particular the driver, has to look in order to be able to see the external device. This is particularly advantageous when the external device is a side mirror.

[0015] The invention is based on the fact that the water molecules of the water deposited on the exposed surface are caused to vibrate by IR radiation, which consequently heats the water. The heating of the water condensed or frozen on the exposed surface occurs largely selectively, since the panes themselves typically absorb IR radiation much less strongly, and therefore only negligible heating of the vehicle window occurs. A resulting advantage is that large-area, electrically heatable layers as part of the vehicle window, such as silver layers, can be dispensed with. This leads to simplified, more cost-effective production of the glazing.The permeability of high-frequency radiation, for example, for receiving mobile phone signals, communicating with cloud servers (“Internet of Things”), and the like, is not impaired by the radiant heating system according to the invention, thus resulting in further advantages. The inventors have also discovered that evaporation using IR radiation can be many times faster than with the HVAC / coating variant. By placing the radiation source outside the vehicle interior, occupants can be better protected from heat irritation and potentially burns. Furthermore, the IR radiation is not reduced by the low, but nevertheless present, IR radiation absorption of the vehicle window. The absorption of IR radiation is particularly problematic when the vehicle window is designed as a laminated pane. Laminated panes often have an IR radiation-absorbing lamination interlayer.By mounting the radiation source on the exterior device, the space in the vehicle interior is not restricted, which allows for greater design freedom in the interior.

[0016] The vehicle window can be a monolithic pane, as is often the case with rear windows or side windows. If the vehicle window is a monolithic pane, it has not only an outside surface but also an inside surface facing the vehicle interior. A monolithic pane refers to single glazing, which can, however, also be provided with functional coatings such as an IR-reflective coating and / or a LowE coating (emissivity-reducing coating). Such coatings are advantageously applied to the inside surface of the vehicle window. However, the vehicle window as a monolithic pane does not have more than one pane and also does not have a thermoplastic polymer layer. Alternatively, the vehicle window can also be a laminated pane, as is usually the case with windshields.However, the rear window or the side window(s) of a vehicle can also be designed as a composite pane. If the vehicle window is a composite pane, it comprises an inner pane and an outer pane, as well as a thermoplastic intermediate layer arranged between the inner and outer panes. The outer pane has an outer surface facing away from the thermoplastic intermediate layer, which is also the outer surface of the vehicle window (but which may have coatings). The outer pane also has an interior surface facing the thermoplastic intermediate layer. The inner pane has an interior surface facing away from the thermoplastic intermediate layer, which surface may be coated or uncoated.The coated or uncoated interior-side surface of the inner pane is also the surface of the vehicle pane exposed to the vehicle interior. It is understood that the thermoplastic interlayer is arranged flat between the inner pane and the outer pane. In other words, the main surfaces of the thermoplastic interlayer are arranged essentially parallel to the surfaces of the outer pane and the inner pane. The main surface of an element describes the area of ​​the element with the greatest extent.

[0017] In a preferred embodiment, the vehicle window is a monolithic pane and the outer surface of the vehicle window is uncoated. The vehicle window can be, for example, a windshield, rear window or a side window of the vehicle. Preferably, the vehicle window is a side window of the vehicle. The vehicle window can be permanently installed in the vehicle so that it is not movable. However, the vehicle window can also be movable, for example, it can be wound up and closed as is usual with side windows. The vehicle window can therefore be converted from an open state to a closed state and vice versa during use of the vehicle. By “closed state” is meant in the sense of the invention that the vehicle window essentially completely separates the vehicle interior from the external environment.In the case of a vehicle side window in a car, this would mean the case in which the vehicle side window is wound up, i.e. the window opening is completely closed by the vehicle side window. "Opened state" in the sense of the invention means that the vehicle side window does not completely close the window opening, i.e. the vehicle interior is not completely separated from the outside environment. It is understood that the vehicle side window can also be "partially open", i.e. the window is not opened to its maximum. It is understood that the irradiation of the outer surface of the vehicle window described in the sense of the invention refers to the irradiation of the vehicle window when it is closed, although it is not excluded that areas of the vehicle window can also be irradiated when it is partially open.

[0018] The vehicle windshield has a circumferential edge with an edge surface, which particularly preferably comprises an upper edge and a lower edge, as well as two side edges running between them. The upper edge refers to the edge that faces upwards when installed in the vehicle. The lower edge refers to the edge that faces downwards when installed in the vehicle. The upper edge is often referred to as the roof edge, and the lower edge as the engine edge. The vehicle windshield can have any suitable geometric shape and / or curvature.

[0019] In a preferred embodiment of the vehicle according to the invention, the radiation source is designed such that it can emit IR radiation in the IR wavelength range from 1.8 pm to 3.4 pm, preferably from 1.9 pm to 3.3 pm, particularly preferably from 1.9 pm to 3.0 pm. It is not necessary for the emission band of the radiation source to completely cover the aforementioned ranges. However, the emission band should lie (at least partially) within these ranges. The radiation source is expediently connected to a power supply device. It is precisely in this preferred wavelength range that the absorption and excitation of the water molecules and thus the resulting heating and evaporation are particularly high. Advantageously, it has been shown that with glass the transmission in the wavelength range from 2.9 pm to 3.1 pm is over 70%, in particular at approx. 3.0 pm with approx.85% is particularly large, so that the energy can be used efficiently for defrosting and evaporating water.

[0020] In an alternative embodiment, the radiation source is configured such that it can emit IR radiation in the IR wavelength range from 1.4 pm to 2 pm, preferably from 1.45 pm to 1.95 pm. In this range, IR radiation is particularly energy-intensive and thus very suitable for evaporating water. This wavelength range is particularly preferred if the radiation source comprises or consists of an LED, since LEDs with IR radiation in higher wavelength ranges above 2 pm are difficult to manufacture and can thus be expensive.

[0021] The radiation source preferably comprises an LED, OLED, a laser, and / or a laser diode. The radiation source preferably comprises an 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 radiation sources for generating IR radiation, the radiation source can also comprise a housing in which the radiation sources for generating IR radiation are mounted. Alternatively, the radiation source can be an LED, OLED, a laser, and / or a laser diode.

[0022] 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.

[0023] In a particularly preferred embodiment of the invention, the radiation source is a fiber-bulk hybrid laser. The laser preferably comprises the laser medium Cr:ZnSe / S. The laser is, for example, dimmable, preferably in a range from 1.9 pm to 3.0 pm, so that the wavelength or a wavelength range of the emitted IR radiation can be selected as required. The radiation source or sources can, for example, be band-shaped or spot-shaped. Other geometric shapes are also possible. Several individual radiation sources can also be arranged next to one another at a distance from one another or in band-shaped arrangement (close to one another). In other words, if several spot-shaped LEDs are arranged next to one another, a multi-part, band-shaped radiation source can be formed.This makes it possible to flexibly adapt the number and intensity of the radiation sources to the requirements needed for heating the vehicle window, for example with regard to the spatial-geometric conditions and the required energy demand for an efficient heating effect.

[0024] Regardless of the wavelength range in which the at least one radiation source emits IR radiation and whether the radiation source comprises or consists of an LED, OLED, a laser and / or a laser diode of the aforementioned types, according to the invention a scattering element is arranged between the radiation source and the vehicle window. This means that a scattering element is arranged between the radiation source and the outer surface of the vehicle window. The scattering element is preferably an optical concave lens (also called a scattering lens), a micro-lens array or a holographic lens. The scattering element serves to scatter the IR radiation. Parallel incident IR rays are refracted by the scattering element in such a way that the IR rays are scattered in space.The radiation source is therefore preferably aligned in such a way that the IR radiation emitted by it is scattered at the scattering element, whereby, for example, the IR radiation of a laser can irradiate a larger area of ​​the outer surface of the vehicle window.

[0025] The pane or panes (outer pane and inner pane) of the vehicle window are preferably made of transparent glass, in particular soda-lime glass, which is common for window panes. The panes can, however, in principle also be made of other types of glass (e.g. borosilicate glass, quartz glass, aluminosilicate glass) or transparent plastics (e.g. polymethyl methacrylate or polycarbonate). The thickness of the at least one pane can vary widely. Preferably, panes with a thickness in the range of 0.8 mm to 5 mm, more preferably 1.4 mm to 2.5 mm, for example those with the standard thicknesses of 1.6 mm or 2.1 mm, are used. The at least one pane can be toughened, partially toughened or prestressed. If at least one of the panes is to be toughened, this can be thermal or chemical prestressing.For the purposes of the invention, “at least one pane” means the inner pane and / or the outer pane if the vehicle pane is designed as a composite pane, or the individual pane of the vehicle pane if it is designed as a monolithic pane.

[0026] The vehicle window can have any three-dimensional shape. Preferably, the at least one pane of the vehicle window has no shadow zones, allowing it to be efficiently coated by cathode sputtering. Preferably, the vehicle window is flat or slightly or strongly curved in one or more directions of space.

[0027] If the vehicle window is designed as a composite window, the thermoplastic intermediate layer is preferably formed as at least one thermoplastic composite film and is based on ethylene-vinyl acetate (EVA), polyvinyl butyral (PVB), or polyurethane (PU), or mixtures or copolymers or derivatives thereof, particularly preferably based on polyvinyl butyral (PVB), and additionally contains additives known to those skilled in the art, such as plasticizers. The thermoplastic film preferably contains at least one plasticizer.

[0028] The thermoplastic intermediate layer can be formed by a single film or by more than one film. The thermoplastic intermediate layer can be formed by one or more thermoplastic films arranged one above the other, wherein the thickness of the thermoplastic intermediate layer after lamination of the layer stack is preferably from 0.25 mm to 1 mm, typically 0.38 mm or 0.76 mm. The thermoplastic intermediate layer can also be formed from a film that is colored in some areas and is thus opaque. The intermediate layer can also be formed from more than one film, i.e. at least two films, and the at least two films extend over different regions of the surface of the composite pane.

[0029] The thermoplastic intermediate layer is preferably a thermoplastic film without functional properties, i.e., a thermoplastic film without functional properties other than thermoplastic properties. Alternatively, the thermoplastic intermediate layer can be a thermoplastic film with acoustically dampening properties, an IR-reflecting thermoplastic film, and / or a UV-absorbing thermoplastic film. If something is "based" on a polymeric material, it consists predominantly of this material, i.e., at least 50%, preferably at least 60%, and in particular at least 70%. It can therefore also contain other materials such as stabilizers or plasticizers.

[0030] In a further preferred embodiment of the invention, which can be combined with the aforementioned embodiments, the external device is a side camera of the vehicle. The side camera preferably comprises a housing and a camera arranged in the housing. The camera preferably serves as a replacement for a side mirror and is intended to film the traffic behind. Alternatively or additionally, the camera can also be intended to film the traffic to the side or the traffic ahead. The camera is therefore a video camera that records images and preferably transmits them to an on-board computer (wirelessly or via cable). The on-board computer can display the images recorded by the camera, for example, on a display in the vehicle interior, so that the driver has an overview of the (rear) traffic.This makes it easier to avoid blind spots and, depending on the position of the display, the driver hardly or not at all needs to look away from the road. The images recorded by the camera can also be saved on the on-board computer or another data storage device if necessary, which can be particularly helpful in investigating traffic accidents. However, the images are preferably transmitted to the display in the vehicle interior and shown there, at least in real time. Mounting the radiation source on the side camera is particularly suitable because it eliminates the need for an external device specifically designed to illuminate the vehicle window; instead, a device already designed for a different function can be used.

[0031] The side-facing camera preferably also comprises a pane that is inserted into an opening in the housing. The pane is intended to separate the interior of the housing from the outside environment. The pane is preferably at least transparent enough for the camera to film the traffic through it. The pane is preferably transparent with a light transmittance of at least 50%, preferably at least 70%. The pane is preferably made of glass, such as soda-lime glass, borosilicate glass, quartz glass, or aluminosilicate glass, or transparent plastics, such as polymethyl methacrylate or polycarbonate. The pane of the side-facing camera is particularly preferably arranged between the interior of the housing and the outside surface of the vehicle window. The pane protects the camera from mechanical damage.

[0032] Particularly preferably, in addition to the camera, the at least one radiation source is also arranged in the housing of the side-view camera. The radiation source is arranged in the housing such that it can irradiate the outer surface of the vehicle window. The housing therefore has an opening into which a pane as described above is preferably inserted. The pane is preferably arranged between the vehicle window and the radiation source such that a portion of the IR radiation emitted by the radiation source initially transmits through the pane before striking the outer surface of the vehicle window. The radiation source therefore irradiates at least a region of the pane of the side-view camera, preferably at least 50%, particularly preferably at least 70%, in particular at least 90% of the main surface of the pane.This has the significant advantage that, in addition to the vehicle window, the side camera window can also be kept free of water, providing better protection for the radiation source from external mechanical damage. The IR radiation transmittance of the window positioned between the vehicle window and the radiation source can be determined by spectrophotometric testing in accordance with ISO 9050.

[0033] In a preferred embodiment of the invention that is an alternative to the aforementioned further preferred embodiment, the exterior device of the vehicle is designed as a side mirror. The side mirror preferably comprises a housing and a reflective element. By reflective element, it is meant that the element has at least one surface that reflects sufficient visible light so that a vehicle occupant, in particular the driver, can visually perceive the traffic behind through the reflection on the reflective element. The reflective surface of the reflective element faces the external environment. The reflective element can, for example, be a substrate coated with a metal coating (preferably aluminum) or a dichroic dielectric mirror. The reflective element is preferably arranged in an opening of the housing, such that the reflective element separates a housing interior from the external environment.The reflective element is preferably arranged in the housing so that it can be moved manually or electronically, so that the element can be positioned at an angle suitable for the user (as is common for side mirrors in vehicles). Particularly preferably, the radiation source is arranged inside the housing of the side mirror. The radiation source is arranged in the housing such that it can irradiate the outer surface of the vehicle window. The reflective element is preferably arranged between the vehicle window and the radiation source, wherein the reflective element is provided with a recess through which the IR radiation from the radiation source can be emitted. The recess is preferably arranged in an edge region of the reflective element. The reflective element can also have no recess and be arranged outside the beam path of the radiation source.For example, the radiation source can be located in an edge area of ​​the housing opening, with the reflective element not extending beyond this edge area. To protect the radiation source from external damage, the recess or edge area can be provided with a protective screen positioned between the radiation source and the vehicle window.

[0034] The reflective surface of the reflective element preferably reflects visible light by at least 30%, particularly preferably by at least 50%, most particularly preferably by at least 70%, in particular by at least 90%. Reflection in a specific percentage range, within the meaning of the invention, means an average reflection factor at a defined angle of incidence (65°).

[0035] For the purposes of the invention, "opaque" means a light transmittance (according to ISO 9050:2003) for visible light (380 nm to 780 nm) of less than 30%, preferably less than 20%, particularly preferably less than 5%, and especially less than 0.1%. "Transparent" for the purposes of the invention means a light transmittance (according to ISO 9050:2003) for visible light of at least 50%, preferably at least 60%, and particularly preferably at least 70%. For the determination of the light transmittance according to ISO 9050:2003 (see section 3.3 of the standard), the relative spectral distribution of illuminant D65 (see, for example, ISO 11664-2:2007) and / or the relative spectral distribution of illuminant A (see, for example, ISO 11664-2:2007) can be used for the determination. In other words: the described light transmittance ranges apply to the determination using illuminant A and / or illuminant D65.

[0036] The reflectance is measured at an angle of incidence of 65° to the surface normal of the reflective surface (the surface normal is the vector perpendicular to the reflective surface of the reflective element). The reflectance describes the proportion of the total incident visible radiation that is reflected. It is expressed as a percentage (relative to 100% incident radiation) or as a unitless number from 0 to 1 (normalized to the incident radiation). Plotted as a function of wavelength, it forms the reflection spectrum. The information on the reflectance or reflection spectrum refers to a reflection measurement with a light source that radiates uniformly in the considered spectral range with a normalized radiation intensity of 100%.

[0037] In a further preferred embodiment of the vehicle according to the invention, the vehicle window is provided with an IR-reflecting coating that overlaps at least the area irradiated with IR radiation by the radiation source. The IR-reflecting coating is preferably arranged at least congruent with the area irradiated with IR radiation by the radiation source. The IR-reflecting coating particularly preferably extends over at least 50% of the surface, particularly preferably over at least 70% of the surface, and in particular completely over the surface of the vehicle window. The IR-reflecting coating is preferably applied to the interior-side surface of the vehicle window. If the vehicle window is designed as a composite window, the coating can also be applied to the exterior surface of the inner window or the interior-side surface of the outer window.Alternatively, the IR-reflective coating can also be applied to a transparent film (e.g., a PET film) and positioned in the thermoplastic interlayer, i.e., between the outer and inner panes. The IR-reflective coating protects the vehicle interior from the IR radiation from the radiation source and enhances the de-icing and evaporating effect of the water or frost deposits adhering to the vehicle window, as the IR radiation is reflected back to the exposed outer surface of the vehicle window.

[0038] The IR-reflecting coating can comprise metallic layers or be metal-free. Particularly preferably, the IR-reflecting coating comprises at least one silver layer and preferably a plurality of silver layers. Such silver layers have particularly advantageous reflection properties while simultaneously achieving high transmission in the visible spectral range. The thickness of a silver layer is preferably from 1 nm to 50 nm, particularly preferably from 5 nm to 25 nm. In this range for the thickness of the silver layer, an advantageously high transmission in the visible spectral range and a particularly advantageous electrical conductivity are achieved. Most preferably, the IR-reflecting coating comprises at least two silver layers, in particular at least three silver layers. Preferably, at least one dielectric layer is arranged between each two adjacent silver layers of the coating.A dielectric layer contains at least one individual layer of a dielectric material, for example containing a nitride such as silicon nitride or an oxide such as aluminum oxide. However, dielectric layers can also comprise multiple individual layers, for example individual layers of a dielectric material, smoothing layers, matching layers, blocking layers, and / or anti-reflection layers. The thickness of a dielectric layer is, for example, from 10 nm to 200 nm. This achieves the technical advantage, for example, that infrared light can be effectively blocked. The blocking of infrared light is particularly well achieved when the infrared protective layer comprises at least two silver layers, particularly preferably three silver layers, and in particular exactly three silver layers.

[0039] The IR-reflective coating has a lower refractive index than the window to which it is applied. The IR-reflective coating preferably has a refractive index of less than 1.5, preferably less than 1.4. This effectively reflects the IR radiation, increasing the probability that the IR radiation will hit a water-covered area on the exterior surface of the vehicle window.

[0040] Refractive indices in the context of the present invention are generally given relative to a wavelength of 1500 nm. Methods for determining refractive indices are known to those skilled in the art. The refractive indices specified in the context of the invention can be determined, for example, by ellipsometry, using commercially available ellipsometers. Unless otherwise stated, the specification of layer thicknesses or thicknesses refers to the geometric thickness of a layer.

[0041] In a further preferred embodiment of the invention, the vehicle further comprises a moisture detector, for example an IR sensor, for detecting water on the outside surface of the vehicle window, and a control unit. The moisture detector is preferably configured to send a signal to the control unit when water is present on an area of ​​the outside surface of the vehicle window that is irradiated by the radiation source during operation. In this case, the control unit is configured to electronically control the radiation source, at least upon receipt of the signal, so that the radiation source radiates IR radiation onto the outside surface of the vehicle window. This offers the advantage that the radiation source is only in operation when water is deposited on the vehicle window, thereby significantly reducing the energy consumption of the radiation source.The moisture detector is preferably mounted on the vehicle window or the exterior device, such as the side mirror or the side camera, so that it can effectively detect water condensed on the outside surface of the vehicle window.

[0042] In a preferred embodiment of the invention, the vehicle additionally comprises at least one further exterior device according to the invention with a radiation source attached to it, as well as at least one further vehicle window (also called a second vehicle window). The radiation device is arranged relative to the second vehicle window of the vehicle such that, during operation, the radiation source irradiates at least one outer surface of the second vehicle window, which is exposed to the external environment, in whole or in part. Preferably, the two exterior devices are each a side camera or a side mirror of the vehicle according to the embodiments of the invention described above. Preferably, the vehicle window according to the invention and the second vehicle window are each side windows of the vehicle.If the exterior device for the first vehicle window is a side mirror, the exterior device for the second vehicle window is preferably also a side mirror. If the exterior device for the first vehicle window is a side camera, the exterior device for the second vehicle window is preferably also a side camera. The vehicle according to the invention can also have more than two exterior devices and two vehicle windows, each of which is irradiated by a radiation source attached to the exterior device.

[0043] The vehicle can be, for example, a passenger car, a truck, a motor vehicle, a tractor, or a bus. The vehicle is preferably a passenger car. The vehicle can be equipped with an internal combustion engine, comprising, for example, a gasoline engine or a diesel engine, an electric drive comprising a fuel cell and / or an accumulator, or a hybrid drive. Hybrid drives and electric drives are particularly suitable because the radiation source is electrically operated. Such drive types must be energy-efficient, since otherwise the range of the vehicle can be significantly reduced, whereby the advantages of removing moisture using the vehicle according to the invention become particularly clear. Furthermore, the invention extends to a method for removing moisture using the vehicle according to the invention.For the purposes of the invention, "moisture" refers to water in a liquid or frozen state. The process comprises the following steps in the order mentioned:

[0044] (A) Activation of the radiation source and

[0045] (B) Emitting IR radiation by the radiation source onto at least a portion of the exterior surface of the vehicle window to remove water adhering thereto.

[0046] In a preferred embodiment of the method according to the invention, the radiation source is activated at least upon detection of water on at least one region of the outer surface of the vehicle window by a moisture detector. The vehicle preferably comprises a moisture detector and a control unit as described above, such that upon detection of water by the moisture detector, a signal is sent to the control unit and the control unit controls the radiation source such that it is activated according to the method and then step B of the method is carried out. Particularly preferably, step B of the method according to the invention is ended and the radiation source deactivated when the moisture detector no longer detects water on the outer surface of the vehicle window. The radiation source therefore only irradiates the vehicle window when the moisture detector detects water.In addition to or independently of this embodiment, the method can also be started and ended manually, for example by a vehicle occupant.

[0047] The various embodiments of the invention can be implemented individually or in any combination. In particular, the aforementioned features can be used not only in the specified combinations, but also in other combinations or on their own, unless they are explicitly described and described as alternatives to one another, without departing from the scope of the present invention.

[0048] The invention is explained in more detail below using exemplary embodiments, with reference to the accompanying figures. They show, in simplified form and not to scale:

[0049] Figure 1 The rear of an embodiment of the vehicle according to the invention, Figure 2 Vehicle door with vehicle window and external device of the vehicle according to the invention

[0050] Vehicle from Figure 1 ,

[0051] Figures 3-5 show various embodiments of the external device with radiation source of the vehicle according to the invention and

[0052] Figure 6 shows an absorption spectrum of water (liquid state).

[0053] Figure 1 shows an embodiment of the vehicle 100 according to the invention, wherein the rear of the vehicle 100 is shown with a view of the trunk and rear window. The vehicle 100 is a passenger car of the sedan type, wherein the invention is not restricted to specific types and models of vehicles. Figure 2 shows a further aspect of the vehicle 100 according to the invention from Figure 1, wherein a vehicle door 101 of the vehicle 100 with an exterior device 2 and a vehicle window 1 is shown. The vehicle window 1 is shown in a plan view with a view of the outer surface I. The exterior device 2 in this example is a side mirror as shown in Figure 3; however, it can also be, for example, a side mirror as shown in Figure 4 or a side camera as shown in Figure 5. The exterior device 2 is shown in a side view in Figure 2, so only the radiation source 3 and the housing 6 of the exterior device 2 can be seen.

[0054] In addition to a first exterior device 2, the vehicle 100 also comprises a further, second exterior device 11, which is fastened to the opposite vehicle door and also represents a side mirror as shown in Figure 3; here, too, this exterior device 11 can, for example, also be a side mirror as shown in Figure 4 or a side camera as shown in Figure 5. Each of the exterior devices 2, 11 comprises a radiation source 3, which is designed such that it can emit IR radiation 4 in the wavelength range from 1.3 pm to 3.5 pm. The radiation sources 3 are arranged relative to the vehicle window 1, 12 of the respective vehicle door 101, to which the exterior devices 2, 11 are fastened, such that they can irradiate, in particular, the area P of the vehicle window 1, 12, which allows the driver a view of the exterior device 2, 11.However, the radiation sources 3 can also be arranged and configured such that they can irradiate a different area or additional areas of the vehicle window 1, 12. The irradiation 4 can effectively remove watery coating 5 on the vehicle window 1, 12. A major advantage here is that the radiation sources 3 are arranged outside the vehicle interior 8 and thus do not reduce the space in the interior 8. A further advantage is that vehicle occupants cannot inadvertently enter the beam path of the radiation source 3, which could lead to irritation or, in the worst case, burns for the occupants.

[0055] Reference is now made to Figures 2 and 3, which describe the first vehicle door 101 and the first exterior device 2 attached thereto. The facts described there also apply analogously to the second vehicle door (this is, for example, the driver's door) and the second exterior device 11 attached thereto. The vehicle door 101 in Figure 2 is, for example, the vehicle passenger door, and the exterior device 2, as a side mirror, is attached to a door position typical for vehicles. Attached to the vehicle door 101 above the vehicle window 1 is a moisture detector 10, which is connected to a control unit (not shown). The moisture detector 10 is, for example, an IR sensor. The moisture detector 10 detects watery coating and / or frost 5 on the outer surface I of the vehicle window 1 in the area P.As soon as the detector 10 detects water 5, it transmits a signal to the control unit, which then controls the radiation source 3 so that the radiation source 3 emits IR radiation 4 onto the area P of the vehicle window 1.

[0056] The radiation source 3 is attached to the housing 6 of the external device 2, for example by means of an adhesive. In addition to the housing 6, the external device 2 also comprises a reflective element 7, which is, for example, a substrate with a reflective coating. The reflective element 7 is inserted into an opening in the housing 6 so that a housing interior (not shown) is separated from the external environment 9. The reflective coating is applied to a surface of the substrate facing the external environment 9 and serves as a mirror that the driver can use to monitor rear traffic. The surface of the reflective element 7, which is made reflective by means of the coating, reflects, for example, at least 70% of the incident visible light. The substrate is made of glass, for example, and the reflective coating is, for example, an aluminum coating.The radiation source 3 is equipped with a scattering element 13 for scattering the IR radiation 4. A scattering element 13 for scattering the IR radiation 4 is thus arranged between the radiation source 3 and the vehicle window 1. The scattering element 13 is, for example, an optical concave lens.

[0057] Figure 4 shows an alternative exterior device 2 as a side mirror. In this embodiment, the radiation source 3 is not attached to the outside of the housing 6 of the exterior device 2, but rather inside the housing interior. The radiation source 3 is arranged in a top view in an edge region of the side mirror, so that the reflective element 7 remains clearly visible and usable. The radiation source 3 comprises, for example, several lasers arranged in a band-like manner, preferably dimmable lasers such as fiber-bulk hybrid lasers with a Cr:ZnSe / S medium. The reflective element 7 is arranged between the radiation source 3 and the vehicle window 1, wherein the reflective element 7 has a recess in the region of the radiation source 3 so that the beam path of the radiation source 3 is not blocked. Each laser of the radiation source 3 is equipped with a scattering element 13 at a suitable distance from the emission surface of the laser.The scattering element 13 serves to scatter the light from the laser beam, allowing a larger area of ​​the vehicle window 1 to be irradiated. The scattering elements 13 are thus arranged in the beam path of the individual lasers of the radiation source 3. The scattering element 13 is, for example, an optical concave lens. A major advantage of this invention is that the radiation source 3 can be arranged with better protection against external damage.

[0058] Figure 5 shows a further alternative embodiment of the external device 2, wherein the external device 2 in this embodiment is not designed as a side mirror of the vehicle 100, but as a side camera. In addition to a housing 6, the external device 2 also comprises a camera 15, which is intended to film the rear traffic. Furthermore, the external device 2 comprises a pane 14, which is inserted into an opening in the housing 6 and separates the housing interior from the external environment 9. The camera 15 is arranged in the housing interior. The camera 15 films through the pane 14, wherein the pane 14 protects the camera 15 from external damage. The pane 14 is transparent to visible light and consists, for example, of mineral glass or plastic glass.The pane 14 is arranged between the radiation source 3 and the vehicle window 1, so that the IR radiation 4 emitted by the radiation source 3 must first be transmitted through the pane 14 before it can strike the outer surface I of the vehicle window 1. The pane 14 is therefore designed such that it is at least partially permeable to IR radiation 4. In addition to the camera 15, the radiation source 3 is also arranged in the interior of the housing and comprises several lasers and scattering elements 13 analogously to that described for Figure 4. Side-view cameras are a popular replacement for side mirrors, particularly in electric vehicles. A major advantage of this design is that the radiation source 3 can also clear the pane 14 of the side-view camera of water 5 in addition to the vehicle window 1. Figure 6 shows an absorption spectrum of water in the liquid state. The diagram shows that water molecules, for example, at a wavelength of approx.3 pm have a particularly high absorption coefficient. In a preferred embodiment, a radiation source in the IR wavelength range from A = 2.5 pm to A = 3.3, particularly preferably from A = 2.9 to A = 3.1 pm, is used for the vehicle window, since in this preferred range.

[0059] Wavelength range, the absorption and excitation of the water molecules and thus the resulting heating and evaporation is particularly great. In the event that a pane or a reflective element is arranged between the radiation source and the vehicle window, the pane 14 or the reflective element 7 (see, for example, Figures 4 and 5) preferably has a transmission in the wavelength range from A = 2.9 to A = 3.1 pm of over 70%, in particular at approximately A 3.0 pm of approximately 85%, so that the radiation energy can be used efficiently for de-icing and evaporating water in the corresponding areas.

[0060] List of reference symbols

[0061] 1 vehicle window

[0062] 2 external device

[0063] 3 Radiation source

[0064] 4 IR radiation

[0065] 5 Water

[0066] 6 housings

[0067] 7 reflective element

[0068] 8 Vehicle interior

[0069] 9 external environment

[0070] 10 Moisture detector

[0071] 11 additional outdoor devices

[0072] 12 additional vehicle windows

[0073] 13 Dispersal element

[0074] 14 slices

[0075] 15 Camera

[0076] 100 vehicles

[0077] 101 Vehicle door

[0078] P area

[0079] I outside surface of the vehicle window 1

Claims

Patent claims 1. Vehicle (100), comprising at least one vehicle window (1) with an outer surface (I) exposed to the external environment (9), at least one external device (2) mounted outside the vehicle interior (8), wherein at least one radiation source (3) for IR radiation (4) in the IR wavelength range from 1.3 pm to 3.5 pm is mounted on the external device (2), the radiation source (3) is arranged relative to the vehicle window (1) such that the radiation source (3) irradiates at least the outer surface (I) of the vehicle window (1) entirely or in a region (P) with IR radiation (4) during operation, and wherein a scattering element (13) for scattering the IR radiation (4) is arranged between the radiation source (3) and the vehicle window (1).

2. Vehicle (100) according to claim 1, wherein the vehicle window (1) is provided with an IR-reflecting coating which overlaps at least with the region (P).

3. Vehicle according to claim 1 or 2, wherein the vehicle window (1) is a monolithic window and the outer surface (I) of the vehicle window (1) is free of coating.

4. Vehicle (100) according to one of claims 1 to 3, wherein the radiation source (3) comprises at least one LED, a laser and / or a laser diode, preferably at least one fiber-bulk hybrid laser, particularly preferably with the laser medium Cr:ZnSe / S.

5. Vehicle (100) according to one of claims 1 to 4, wherein the radiation source (3) can emit IR radiation (4) in the IR wavelength range from 1.8 pm to 3.4 pm, preferably from 1.9 pm to 3 pm.

6. Vehicle (100) according to one of claims 1 to 5, wherein the external device (2) is a side camera of the vehicle (100), the side camera comprising a housing (6) and a camera (15) arranged in the housing (6).

7. Vehicle (100) according to claim 6, wherein the side camera further comprises a pane (14) arranged between the camera (15) and the vehicle pane (1) and in an opening of the housing (6).

8. Vehicle (100) according to claim 7, wherein the radiation source (3) is arranged in the housing (6) in such a way that the IR radiation (4) emitted by the radiation source (3) must first be transmitted through the window (14) before it can strike the outer surface (I) of the vehicle window (1).

9. Vehicle (100) according to one of claims 1 to 5, wherein the exterior device (2) is a side mirror of the vehicle (100), the side mirror comprising a housing (6) and a reflective element (7) arranged in an opening of the housing (6), the reflective element (7) having a surface which is reflective for visible light and which faces the external environment (9).

10. Vehicle (100) according to one of claims 1 to 9, further comprising a moisture detector (10) and a control unit, wherein the moisture detector (10) is arranged and configured such that it sends a signal to the control unit when water (5) is located on the area (P) of the outside surface (I) of the vehicle window (1), wherein the control unit is configured such that, at least upon receipt of the signal, it electronically controls the radiation source (4) so ​​that the radiation source (4) irradiates the outside surface (I).

11. Vehicle (100) according to one of claims 1 to 10, wherein the vehicle window (1) is a side window of the vehicle (100).

12. Vehicle (100) according to one of claims 1 to 11, further comprising at least one further external device (11) with a radiation source (4) attached to it, wherein the radiation source (4) is arranged relative to a further vehicle window (12) of the vehicle (100) such that the radiation source (4) irradiates, in operation, at least one outer surface (I) of the further vehicle window (12) exposed to the external environment (9), entirely or in regions, wherein the further vehicle window (12) is preferably a side window of the vehicle (100).

13. A method for removing moisture using a vehicle (100) according to any one of claims 1 to 12, comprising the steps of: (A) activating the radiation source (3) and (B) emitting IR radiation (4) from the radiation source (3) to at least one Area (P) of the outer surface (I) of the vehicle window (1) for removing water (5) adhering thereto.

14. The method according to claim 13, wherein the method steps (A) and (B) are carried out as a result of the detection of water (5) on the region (P) of the outside surface (I) by a moisture detector (10).

15. The method according to claim 14, wherein the radiation source (3) is deactivated and the method is terminated when the moisture detector (10) detects no water (5) on the area (P) of the outside surface (I).

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