Glazing unit and associated coating removal method

Abstract

The present invention discloses a glazing unit including a glass sheet having low reflectivity to RF radiation, a coating system having high reflectivity to RF radiation disposed on the glass sheet, and at least one frequency-selective uncoated grid portion on the coating system, the at least one frequency-selective uncoated grid portion including a first uncoated grid and a second uncoated grid, each of the first uncoated grid and the second uncoated grid having a uncoated area in the form of grid lines arranged in a mesh, the first uncoated grid being connected to the second uncoated grid at a connection region, at least in the connection region, the first uncoated grid including a rake design with at least one missing tooth, and the second uncoated grid including a rake design. The present invention also discloses related methods, related apparatus, and uses.

Description

[Technical Field]

[0001] The present invention relates generally to a glazing unit including a glass sheet having low reflectivity to RF radiation and a coating system having high reflectivity to RF radiation disposed on the glass sheet, and more specifically to a tempered glazing unit including at least a frequency-selective coating-removed grid portion on the coating system.

[0002] The invention therefore relates to a variety of areas in which glazing units are used, whether attached to stationary objects, for example buildings, or to mobile objects, for example vehicles, trains. [Background technology]

[0003] In recent years, in order to prevent global warming, it has become common to reduce power consumption, for example by using air conditioners sparingly for cooling purposes. Therefore, attempts have been made to impart a coating system function that reflects infrared rays (heat rays) to glazing units of vehicles, buildings, etc., thereby reducing the amount of heat absorbed into the interior of the vehicle or building from sunlight.

[0004] However, such coating systems are typically electrically conductive and highly reflective to RF radiation, making them efficient reflectors of broadband radio frequency signals. Furthermore, commercial buildings, automobiles, trains, and the like tend to use other materials that further block RF signals. Materials such as concrete, brick, mortar, steel, aluminum, roofing tar, gypsum wallboard, and some types of wood all offer varying degrees of RF absorption. As a result, many newer structures significantly impede RF signals from entering and exiting the building. This effect can impede reception or transmission by antennas and / or terminals.

[0005] As a method for imparting a heat ray reflecting function to a window or the like, for example, a method of forming a thin film (heat ray reflecting film) containing a metal having a heat ray reflecting function, such as silver, on a glass sheet or the like can be mentioned.

[0006] When a substrate having a heat ray reflecting function is applied to, for example, a window glass, high transparency to radio waves of a certain frequency is also required, but the coating system has high reflectivity to RF radiation.

[0007] Nevertheless, RF devices have become an important part of modern life, especially with the explosive proliferation of cellular smartphones, tablets, and Internet of Things (IoT) devices, which require electromagnetic fields to penetrate deep into buildings or automobiles for indoor coverage, even at high spectrum frequencies up to 110 GHz. Such devices may include cellular transceivers, wireless local area network ("Wi-Fi") transceivers, global positioning system (GPS) receivers, Bluetooth transceivers, and possibly other RF receivers (e.g., FM / AM radio, UHF, etc.). As these devices grow in popularity, it is increasingly important to be able to use RF-based functionality within the enclosed confines of modern commercial buildings.

[0008] In addition, in order to increase the speed and capacity of wireless communications, higher frequency bands are being used, such as the frequency band of the fifth generation mobile communication system (5G). Therefore, even if high-frequency electromagnetic waves with a wide frequency band are used for mobile communications, etc., it is necessary to have a wideband frequency selective surface so that waves of different frequencies can be reliably transmitted within the glazing unit.

[0009] The ITU's IMT-2020 specification calls for speeds of up to 20 Gbps achievable with wide channel bandwidths, and the Massive MIMO 3rd Generation Partnership Project (3GPP) plans to propose 5G New Radio (NR) as its proposed 5G communications standard. 5G NR may include lower frequencies below 6 GHz and millimeter wave above 15 GHz. However, early deployments using 5G NR software on 4G hardware (non-standalone) have only modest improvements in speed and latency compared to new 4G systems, estimated at 15% to 50%. Furthermore, IoT requires as wide indoor coverage as possible for critical machine-type communication (MTC), where robots and industrial equipment are remotely controlled over 5G wireless, rather than massive MTC.

[0010] For example, in recent years, one method for transmitting radio waves in the frequency band of several hundred MHz to several tens of GHz or more, which are used in fourth-generation mobile communication systems (4G) or fifth-generation mobile communication systems (5G), is to partially remove the heat ray reflective film used to coat the substrate by methods such as laser etching.

[0011] Among these, a known method for appropriately transmitting radio waves having a predetermined frequency while maintaining the functionality of the coating system is to remove the coating system and form a periodic pattern consisting of multiple lines in the area where there is no heat ray reflective film, for example, to form a grid shape that forms an FSS in the form of parallel lines or grid lines arranged in a mesh pattern.

[0012] When removing a heat-reflecting coating by laser etching, the size of the area that can be laser-processed in a single process is generally limited. For example, U.S. Patent Application Publication No. 2013 / 0295300 describes a method for relatively quickly laser-processing a relatively large area in a single process, but the size of the area that can be laser-processed in a single process may still be insufficient for the entire area to be processed. Therefore, when performing laser processing on an area larger than the area that can be processed in a single process, a pattern formed to a predetermined size that can be processed in a single process is formed multiple times and arranged consecutively. As a result, a continuous pattern can be formed across the entire desired area by connecting the tile-shaped portions from which the coating has been removed, like a so-called patchwork.

[0013] In this case, to avoid impairing radio wave transparency or aesthetic appearance, it is ideal that there be no interruptions or misalignments of the patterns at the joints between multiple patterns formed by different processes. However, it is difficult to completely control the pattern formation position, and it is necessary to consider the possibility of some error in the pattern formation position during laser processing. In particular, since interruptions in the pattern are likely to impair radio wave transparency, to prevent this, it is necessary to connect the patterns as reliably as possible.

[0014] On the other hand, when forming a grid pattern, for example, by arranging multiple grid patterns formed by different processes so that they partially overlap each other, it is possible to suppress pattern discontinuities that impair radio wave transparency. EP 2890655 describes that a first grid surface is connected to a closed comb structure of a second grid surface via an open comb structure, thereby preventing misalignment such as double lines and the occurrence of uncoated areas in the overlapping areas.

[0015] However, with the above-mentioned technology, for example, when forming a parallel line pattern, it is difficult to suppress the interruption between multiple patterns formed by different processes, which limits the degree of freedom of the pattern that can be selected. Moreover, with such a solution, the joints between adjacent tiles are visible because each connection point is aligned, and the laser passes through the joint twice, which causes the effect of the alignment part being too visible. Therefore, the user can see the tiles due to the connection points of these alignment parts. Summary of the Invention

[0016] An object of one embodiment of the present invention is to provide a glazing unit that can increase the transmission of radio waves of specific frequencies, for example lower frequencies below 6 GHz and / or millimeter waves above 15 GHz, through the glazing unit while making the connections between adjacent tiles nearly invisible.

[0017] In a first aspect, the present invention relates to a glazing unit including a glass sheet having low reflectivity to RF radiation, a coating system having high reflectivity to RF radiation disposed on the glass sheet, and at least one frequency-selective uncoated grid portion on the coating system, the at least one frequency-selective uncoated grid portion including a first uncoated grid and a second uncoated grid, each of the first uncoated grid and the second uncoated grid having an uncoated region in the form of grid lines arranged in a mesh, the first uncoated grid being connected to the second uncoated grid at a connection region.

[0018] The solution defined in a first aspect of the invention is based on the fact that, at least in the connection region, the first decoated grid comprises a rake design with at least one missing tooth.

[0019] The solution defined in the first aspect of the invention is also based on the fact that, at least in the connection region, the second decoated grid comprises a rake design. Preferably, at least in the connection region, the rake design of the second decoated grid has at least one missing tooth.

[0020] According to the present invention, at least a first decoated grid can be connected in the connection area with a rake design having at least one missing tooth to a second decoated grid with a rake design having at least one missing tooth by obscuring the connection between the decoated grids.

[0021] In a second aspect, the present invention relates to a method for removing a coating from a glazing unit including a glazing panel comprising a glass sheet (10) having low reflectivity to RF radiation and a coating system (20) having high reflectivity to RF radiation disposed on the glass sheet, the method comprising a step B of forming at least one frequency-selective, decoated grid portion (30) on the coating system, which comprises the following substeps: Substep B1, forming a first decoated grid having decoated regions in the form of grid lines arranged in a mesh; Substep B2 of forming a second decoated grid having decoated regions in the form of grid lines arranged in a mesh pattern.

[0022] The first uncoated grid is connected to a second uncoated grid at a connection region.

[0023] The solution defined in a second aspect of the invention is based on the fact that the first decoated grid comprises a rake design with at least one missing tooth, at least in the connection region, and that the second decoated grid comprises a rake design with at least one missing tooth, at least in the connection region. Preferably, the rake design of the second decoated grid comprises at least one missing tooth, at least in the connection region.

[0024] In a third aspect, the present invention relates to a coating removal apparatus for removing a coating from a glazing unit including a glazing panel including a glass sheet with low reflectivity to RF radiation and a coating system with high reflectivity to RF radiation disposed on the glass sheet, by the method according to the second aspect of the present invention.

[0025] It is to be noted that the present invention relates to all possible combinations of features recited in the claims or in the described embodiments.

[0026] Although the following description relates to building applications, it should be understood that the invention may also be applicable to other areas, such as transportation applications such as automobiles or trains.

[0027] This and other aspects of the invention will now be described in more detail with reference to the accompanying drawings, which show various exemplary embodiments of the invention, provided by way of example and not limitation. The drawings are schematic and not to scale. They do not limit the invention in any way. Many more advantages will be explained by way of example. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a schematic diagram of a glazing unit according to a first embodiment of the present invention;

[0029] [Figure 2] 1 is a schematic diagram of a decoated grid according to the present invention;

[0030] [Figure 3] 1 is a schematic diagram of another decoated grid according to the present invention. FIG.

[0031] [Figure 4] FIG. 1 is a schematic diagram of a first uncoated grid connected to a second uncoated grid in accordance with the present invention.

[0032] [Figure 5] FIG. 10 is an enlarged schematic view of the connection area of ​​a first decoated grid connected to a second decoated grid.

[0033] [Figure 6] FIG. 1 is a schematic diagram of a frequency selective decoated grid section including several decoated grids.

[0034] [Figure 7] FIG. 1 is a schematic diagram of several interconnected decoated grids.

[0035] [Figure 8] FIG. 2 is a schematic representation of step B of the method according to the second aspect of the invention.

[0036] [Figure 9] FIG. 2 is a schematic diagram of an embodiment of a method according to a second aspect of the present invention.

[0037] [Figure 10] FIG. 3 is a schematic diagram of another embodiment of the method according to the second aspect of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0038]

[0023] The specific embodiments herein include various modifications, equivalents, and / or alternatives of the corresponding embodiments. The same reference numerals are used throughout the drawings to refer to the same or similar parts.

[0039] As used herein, spatial or directional terms such as "inside," "outside," "upper," "lower," "above," and "below" refer to the present invention as shown in the drawings. However, it should be understood that the present invention can assume various alternative orientations, and therefore, such terms should not be considered limiting. Furthermore, all numbers used in the present specification and claims expressing dimensions, physical properties, processing parameters, amounts of ingredients, reaction conditions, and the like should always be understood to be modified by the term "about." Therefore, unless indicated to the contrary, the numerical values ​​set forth in the following description and claims are approximate and may vary depending on the desired properties sought to be obtained by the present invention. In the following description, unless otherwise specified, the term "substantially" means within 10%, preferably within 5%.

[0040] Furthermore, all ranges disclosed herein should be understood to include the starting and ending values ​​of the range, and to encompass all subranges subsumed therein. For example, a range specified as "1 to 10" should be considered to include all subranges between (and including) a minimum value of 1 and a maximum value of 10, i.e., any subrange beginning with a minimum value of 1 or greater, e.g., 1 to 6.1, and ending with a maximum value of 10 or less, e.g., 5.5 to 10. Furthermore, as used herein, the terms "deposited onto" or "provided onto" mean deposited or provided on, but not necessarily in surface contact with, a substrate. For example, a coating "deposited onto" a substrate does not exclude the presence of one or more other coating films of the same or different composition located between the deposited coating and the substrate.

[0041] Where the term "comprising" is used in the present specification and claims, it does not exclude other elements or steps. Where an indefinite or definite article is used when referring to a singular noun, such as "a," "an," or "the," this includes the plural of that noun unless specifically stated otherwise. As used herein, "configured to" may be used interchangeably with, for example, "suitable for," "capable of," "modified to," "made to," "capable of," or "designed to," in reference to hardware and software, depending on the context. In any context, the phrase "device configured to perform" may mean that the device, together with other devices or components, is "capable of performing."

[0042] Furthermore, terms such as "first," "second," etc. in this specification and claims are used to distinguish between similar elements and are not necessarily used to describe an order in time, space, ranking, or any other respect. It should be understood that terms so used are interchangeable under appropriate circumstances, and that the embodiments of the invention described herein may operate in orders other than those described or illustrated herein. When a component (e.g., a first component) is described as being "coupled (functionally or communicatively)" or "connected" to another component (e.g., a second component), it should be understood that the component may be directly connected to the other component or may be connected to the other component via another component (e.g., a third component).

[0043] It is an object of the present invention to alleviate the aforementioned problems associated with efficient, discrete, frequency selective, decoated grid sections on coating systems.

[0044] In particular, as shown in FIG. 1, the object of the first embodiment of the present invention is a glazing unit 100.

[0045] Glazing Unit The glazing unit according to the invention can be used as a window, in particular for closing an opening in a stationary object such as a building, or for closing an opening in a moving object such as a train, ship or car.

[0046] In Figure 1, the glazing unit has a height measured along the Z axis, a width measured along the X axis, and a thickness measured along the Y axis. The shape of the glazing panel in plan view (XZ plane) is not limited to a rectangle, but can also be a circle, etc. In this embodiment, a rectangle includes not only a rectangle or a square, but also a shape obtained by chamfering the corners of a rectangle or a square. The size and / or shape of the glazing unit depends on the desired application.

[0047] Glass sheet In accordance with the present invention, the glazing unit 100 includes a glazing panel that includes a glass sheet 1 that has low reflectivity to RF radiation.

[0048] A low reflectivity for RF radiation means that most of the RF radiation passes through the material, a high reflectivity for RF radiation means that most of the RF radiation is reflected from the surface of the material and / or absorbed by the material, resulting in attenuation of 20 decibels (dB) or more, and a low reflectivity means attenuation of 10 decibels (dB) or less.

[0049] The shape of the glazing panel in a plan view (XZ plane) is not limited to a rectangle, but may also be a circle, etc. In this embodiment, a rectangle includes not only a rectangle or a square, but also a shape obtained by chamfering the corners of a rectangle or a square.

[0050] In some embodiments, the glass sheet 2 is see-through and transparent to at least visible waves, meaning that the light transmittance is 1% or greater, in order to allow visible light to pass through.

[0051] In some embodiments, the glazing panel includes at least two glass sheets separated by a spacer, which creates a space that is filled with a gas such as argon, thereby improving the thermal insulation of the glazing unit and resulting in an insulated glazing unit.

[0052] In some embodiments, the glazing panel includes at least two glass sheets separated by a spacer, which creates a vacuum space, thereby improving the thermal insulation of the glazing unit and resulting in vacuum insulated glazing (VIG).

[0053] In some embodiments, the glazing panels can be laminated glazing panels for noise reduction and / or penetration safety. Laminated glazing includes glazing panels held together by one or more interlayers positioned between the glazing panels. The interlayers used are typically polyvinyl butyral (PVB) or ethylene-vinyl acetate (EVA), and their hardness can be adjusted. These interlayers keep the glazing panels connected to each other when broken, preventing the glass from shattering into large, sharp pieces.

[0054] Glazing panel materials may include, for example, soda-lime-silica glass, borosilicate glass, or aluminosilicate glass, or other materials such as thermoplastic polymers, particularly polycarbonate for automotive applications, are known, and references to glass throughout this application should not be considered limiting.

[0055] The glazing panel can be manufactured by known manufacturing methods such as the float method, fusion method, redraw, press molding, or stretching method. From the viewpoints of productivity and cost, it is preferable to use the float method as the manufacturing method for the glazing panel 2.

[0056] The glass sheets can be flat or curved according to requirements by known methods such as hot or cold bending.

[0057] Glass sheets can be annealed, tempered, etc. to meet specifications for security and anti-theft requirements.

[0058] The glass sheets can be clear glass or colored glass, which has been colored with a particular composition of glass or by applying, for example, a coating or a plastic layer.

[0059] In the case of several glass sheets, in some embodiments, each glass sheet can be independently processed and / or stained, etc., to improve aesthetics, thermal performance, safety, etc.

[0060] The thickness of the glazing panels is set according to the requirements of the application.

[0061] The glazing panel can be formed into a rectangular shape in plan view by using a known cutting method. For example, the glazing panel can be cut by irradiating the surface of the glazing panel with laser light and cutting the irradiated area on the surface of the glazing panel, or by mechanically cutting with a cutter wheel. The glazing panel can have any shape suitable for the application, such as an automobile windshield, a side window, a sunroof, a train side window, or a building window.

[0062] Additionally, the glazing unit can be assembled in a frame or attached to a double-skin facade, to the bodywork or any other means capable of holding the glazing unit. Some plastic elements can be fastened to the glazing panel to ensure gas and / or liquid tightness, to ensure the fixation of the glazing panel, or to add external elements to the glazing panel.

[0063] Coatings According to the present invention, the glazing unit 100 comprises a coating system 2 that is highly reflective to RF radiation. The coating system 2 is disposed on the glass sheet 1.

[0064] The coating system is highly reflective and has low transmission for RF radiation. Low transmission means transmission at a level of attenuation of 20 decibels (dB) or greater. Low reflection of the glass sheet is understood to mean attenuation at a level of 10 decibels (dB) or less.

[0065] According to the present invention, coating system 2 can be a functional coating, for example, to heat the surface of a glass sheet, to reduce heat buildup inside a building or vehicle, or to keep heat inside during cold weather, although the coating system is thin and primarily transparent to the eye in order to be see-through and allow visible light to pass through.

[0066] The coating system 2 can be made of layers of different materials, at least one of which is electrically conductive. The coating system is electrically conductive in the XZ plane over the majority of one major surface of the glass sheet.

[0067] The emissivity of the coating system 2 of the present invention is 0.4 or less, preferably less than 0.2, particularly less than 0.1, less than 0.05, or even less than 0.04. The coating system of the present invention may include a metal-based low-emissivity coating system, which is typically a thin-layer system comprising one or more, for example, two, three, or four, functional layers based on an infrared radiation-reflecting material and at least two dielectric coatings, each surrounded by a dielectric coating. The coating system of the present invention may particularly have an emissivity of at least 0.010. The functional layers are generally silver layers with a thickness of a few nanometers, most often about 5 to 20 nm. Regarding the dielectric layers, they are transparent, and conventionally, each dielectric layer is fabricated from one or more layers of metal oxides and / or nitrides. These different layers are deposited by vacuum deposition techniques, such as magnetic field-assisted cathode sputtering, more commonly known as "magnetron sputtering," or by chemical vapor deposition, such as CVD or PECVD, or any other known deposition method. In addition to the dielectric layer, each functional layer may be protected by a barrier layer or improved by deposition on it of a wetting layer.

[0068] In some embodiments, the coating system 2 is applied to a dielectric substrate 2, particularly a glazing panel, to transform it into a low-E glazing unit. This metal-based coating system, such as a low-E coating system or a heatable coating system.

[0069] In some embodiments, coating system 2 may be a heatable coating applied onto a dielectric substrate, particularly a glazing panel, for example, to add defrosting and / or demisting functionality.

[0070] The coating system may be, for example, a conductive film. The conductive film may be, for example, a laminated film obtained by sequentially laminating a transparent dielectric, a metal film, and a transparent dielectric, ITO, fluorine-doped tin oxide (FTO), etc. The metal film may be, for example, a film containing at least one selected from the group consisting of Ag, Au, Cu, and Al as a main component.

[0071] Preferably, the coating system is disposed in the XZ plane over a majority of one surface of the glazing unit, more preferably over the entire usable surface of the glazing panel.

[0072] In some embodiments, a masking element, such as an enamel layer, can be added to a portion of the periphery of the glazing unit to hide the transition between the coated and uncoated areas.

[0073] In some embodiments, a glazing unit can include several coating systems applied on the same or different surfaces of the glass sheet.

[0074] In some embodiments where the glazing panel includes several glass sheets, different or the same coating systems can be disposed on different surfaces of the glass sheets.

[0075] Frequency selective coating removed grid section According to the invention, the glazing unit comprises at least one frequency-selective de-coated grid portion 3 on the coating system 2 .

[0076] At least one frequency selective uncoated grid portion is located within the coating system and forms a communication window to allow RF radiation to pass through the coating system and glazing unit depending on grid parameters such as the distance between grid lines and the shape of the grid mesh.

[0077] In the context of the present invention, the term "removed grid portions" includes linearly removed portions of the coating, e.g., by a laser. The linearly removed portions form a mesh pattern. In other words, the removed grid is formed by non-conductive or substantially non-conductive line segments marked in the coating system. Some of the non-conductive or substantially non-conductive line segments intersect with other non-conductive or substantially non-conductive line segments to form the removed grids shown in Figures 1, 2, 3, 4, 5, and 7. Thus, the removed grid is formed by the non-conductive or substantially non-conductive line segments and the intersections of these non-conductive or substantially non-conductive line segments.

[0078] The linear ablation is visible due to the color difference between the ablation and the coating system at some angles of incidence.

[0079] The location of the at least one frequency selective coated removed grid portion depends on the application.

[0080] Decoated grid According to the invention, the at least one frequency selective uncoated grid portion 3 comprises a first uncoated grid 31 and a second uncoated grid 32 .

[0081] As shown in Figures 2-7, the decoated grid has decoated areas in the form of black, mesh-like grid lines, which leaves white zones where the coating system remains, thereby maximizing the surface area of ​​the coating system that remains intact, i.e., the surface area where the coating system is not removed, in order to maintain the properties of the coating system.

[0082] The grid mesh must have a distance between the lines that is significantly smaller than the wavelength of the desired electromagnetic radiation in question, and for this purpose, the metal-containing coating is removed in the form of lines, for example, using a suitable laser. Since only a small amount of the metal-containing coating needs to be removed, the infrared radiation absorption effect is largely maintained.

[0083] Preferably, the width of the section where the coating has been removed can be set to 15 μm to 150 μm, preferably 30 μm to 70 μm, and more preferably substantially 50 μm.

[0084] 4 and 5, the first decoated grid 31 is connected to the second decoated grid 32 at connection regions 51, 52, 53, 54. It should be understood that the first decoated grid and the second decoated grid are adjacent.

[0085] According to the present invention, the term "connection area" corresponds to the connection area between two adjacent decoated grids. Preferably, as shown in Figure 4, the connection area 51 corresponds to an edge of a decoated grid, i.e., the first decoated grid 31, that is connected to a corresponding edge of an adjacent decoated grid, i.e., the second decoated grid 32.

[0086] According to the present invention, at least in the connection region, the de-coated grid comprises a rake design in which the grid lines are not closed by the surrounding grid lines at least on one side, thus forming a rake structure with teeth 322. A rake design is understood to mean an open structure directed towards the outside of the de-coated grid. In the sense of the present invention, a rake design means a structure that includes teeth to form an open structure directed towards the outside of the de-coated grid. To be an open structure, the rake design includes several tooth structures directed towards the outside of the de-coated grid.

[0087] Preferably, the teeth 322 are a series of grid lines to optimize (minimize) the time of the coating removal step.

[0088] In some embodiments, the stripped grid can include a rake design on at least one side other than the connecting side, as shown in Figures 2 and 3. In the figures, the stripped grid has a generally rectangular shape with four edges, each of which has a rake design that can connect to other adjacent stripped grids to form a larger frequency-selective stripped grid section.

[0089] According to the present invention, the rake design of the decoated grids has at least one missing tooth 321, which means that, at least in the connection region, the first decoated grid comprises a rake design and the second decoated grid comprises a rake design with at least one missing tooth 321. Preferably, at least in the connection region, the rake design of the second decoated grid has at least one missing tooth.

[0090] Preferably, along the edge of one decoated grid where it will be connected to another decoated grid, the rake design has a series of teeth and missing teeth. In some embodiments, this series may include several teeth separated by missing teeth and / or several missing teeth separated by at least one tooth.

[0091] According to the invention, in the connection region, the connection between the first decoated grid and the second decoated grid is made via at least one tooth of the rake design of the first decoated grid and / or via at least one tooth of the rake design of the second decoated grid, facilitating the decoating process.

[0092] Preferably, the grid lines form squares and / or rectangles to optimize the coating removal process and reduce the time required to form the decoated grid.

[0093] In some embodiments, the square is substantially a 2x2 mm square. In other embodiments, the square is substantially a 4x4 mm square. The dimensions of the square depend on the desired EM frequencies to be passed through the glazing unit.

[0094] Preferably, the decoated grids that make up the patchwork for creating the frequency-selective decoated grid portions have the same dimensions and the grid lines form the same shapes with the same dimensions in order to optimize the decoating process and reduce the time required to form the frequency-selective decoated grid portions.

[0095] In some other embodiments, depending on the particular application, the dimensions of each decoated grid or the dimensions of the shape formed by the grid lines may vary.

[0096] In some preferred embodiments, the rake design of a first decoated grid can match the rake design of a second decoated grid in the connection region to form a closed grid. This means that, at least in the connection region, the rake design of the first decoated grid is positioned to minimize tooth overlap and maximize the continuity and completion of the grid pattern when engraved together with the second decoated grid. Overlap between corresponding edges is minimized by ensuring that, for corresponding edges, the rakes are complementary, i.e., the teeth of one rake do not overlap the corresponding teeth of the other rake design, and vice versa.

[0097] As shown in Figures 4, 5, and 6, along the edge of one decoated grid that will be connected to another decoated grid, the sequence of teeth and missing teeth of the rake design of the first decoated grid matches the sequence of missing teeth and teeth of the rake design of the second decoated grid.

[0098] More preferably, in some embodiments according to the present invention, the rake design of the first de-coated grid mates complementary to the rake design of the second de-coated grid in the connection region, forming a completely closed grid together, meaning that the rake design of the first de-coated grid has teeth only where the corresponding connection of the rake design of the second de-coated grid has missing teeth, and the rake design of the first de-coated grid has missing teeth only where the corresponding connection of the rake design of the second de-coated grid has teeth. In such embodiments, the de-coated grids formed by the connection of at least the first de-coated grid and the second de-coated grid form a completely closed, complementary grid. The term "complete" means that each mesh-shaped zone has the same dimensions and each edge is formed by a grid line of the first or second de-coated grid.

[0099] As shown in Figures 4, 5, or 7, along the edge of one decoated grid that will be connected to another decoated grid, the series of teeth and missing teeth of the rake design of the first decoated grid mates complementary to the series of missing teeth and teeth of the rake design of the second decoated grid. In such an embodiment, the first decoated grid and the second decoated grid are free of teeth at that edge if teeth extend at corresponding locations on the connected edge of the second decoated grid and the first decoated grid, respectively.

[0100] In the embodiment of Figure 5, the illustrated portion of the rake design of the first decoated grid 31 includes two teeth 322, the rake design of the second decoated grid 32 includes two teeth 322, and there are two missing teeth. Each tooth extends to connect the first decoated grid to the second decoated grid, and there is no overlap, meaning that a tooth is only in front of a missing tooth of the other decoated grid.

[0101] According to some embodiments, as shown in FIG. 5, at least one tooth of the rake design of the first decoated grid contacts or has an overlap O1 with the second decoated grid, and / or at least one tooth of the rake design of the second decoated grid contacts or has an overlap O2 with the first decoated grid.

[0102] The tooth lengths DT1, DT2 are 50% to 150% of the lengths Dh1 or Dv1, Dh2 or Dv2, respectively, depending on the orientation of the decoated wires 331, 332, 333. Preferably, the connecting tooth lengths DT1, DT2 are 100% to 150%, which means that the overlap portions O1, O2 are 0% to 50% of the lengths Dh1 or Dv1, Dh2 or Dv2, respectively.

[0103] In the terms of the present invention, a decoated grid connected to another decoated grid means that at least one decoated wire 331, 332, 333, preferably a tooth, is used to connect the decoated grid and interacts with the decoated wire of another decoated grid.

[0104] In some embodiments, the overlap portion O1 is 0 mm to 0.4 mm, preferably 0 mm to 0.2 mm, and more preferably 0 mm to 0.1 mm.

[0105] In some embodiments, the overlap portion O2 is 0 mm to 0.4 mm, preferably 0 mm to 0.2 mm, and more preferably 0 mm to 0.1 mm.

[0106] The overlap O1, O2 may depend on the dimensions of the grid.

[0107] In some embodiments, the coating removal process may cause adjacent decoated grids to shift, primarily due to misalignment and / or movement of the coating removal device during the coating removal step, resulting in a distance H. It should be appreciated that distance H is preferably minimized and close to 0 mm.

[0108] More preferably, to ensure good RF transparency, the first decoated grid is connected to the second decoated grid by more than 50% of the teeth of the rake design of the first decoated grid, preferably the first decoated grid is connected to the second decoated grid by more than 80% of the teeth of the rake design of the first decoated grid, and more preferably the first decoated grid is connected to the second decoated grid by more than 90% of the teeth of the rake design of the first decoated grid.

[0109] More preferably, to ensure good RF transparency, the first decoated grid is connected to the second decoated grid by more than 50% of the teeth of the rake design of the second decoated grid, preferably the first decoated grid is connected to the second decoated grid by more than 80% of the teeth of the rake design of the second decoated grid, and more preferably the first decoated grid is connected to the second decoated grid by more than 90% of the teeth of the rake design of the second decoated grid.

[0110] Preferably, the majority of the teeth of the connected, decoated grid are used for connection, and even more preferably, all of the teeth are used for connection.

[0111] According to some embodiments, at least one tooth of the rake design of the first decoated grid contacts or has an overlap O1 with the second decoated grid, and / or at least one tooth of the rake design of the second decoated grid contacts or has an overlap O2 with the first decoated grid.

[0112] As shown in FIG. 5, the decoated grid can be connected to two or more adjacent decoated grids at specific connection regions 51, 52, 53, 54 to form a patchwork of decoated grids and increase the surface area of ​​the frequency-selective decoated grid portion.

[0113] Returning to Figures 2 and 3, in some preferred embodiments, to facilitate the decoating step while simultaneously optimizing decoating time, the decoated grid has a general shape of 2x2 with several substantially parallel edges, preferably rectangular or square.

[0114] In such a preferred embodiment, each of the at least two parallel edges has a rake design with a sequence of teeth and missing teeth that matches complementary to the sequence of teeth and missing teeth on the other parallel edge, meaning that along the coating removal lines 331, 332, 333, teeth are present on only one edge and missing teeth on the other edge.

[0115] More preferably, all parallel edges have a rake design with a sequence of teeth and missing teeth that complements and matches the sequence of teeth and missing teeth on the other parallel edges. These specific embodiments allow for the construction of a single decoated grid and its replication as many times as necessary to form the frequency-selective decoated grid portion. Each decoated grid is connected edge-to-edge to adjacent decoated grids. Therefore, to facilitate the decoating process, the decoated grids that make up the patchwork have the same shape, meaning that the decoated lines, teeth, and missing teeth are identical. Because these decoated grids are connected to each other two by two and have the same shape, they fit together like a puzzle to form the frequency-selective decoated grid portion, while simultaneously obscuring the connection points. In fact, each connection between two decoated lines is visible because the coating is removed at least twice at the same point, and the human eye sees an overly bright area at these connection points.

[0116] It should be understood that the edges of the decoated grid that form the boundary of the frequency selective decoated grid portion 3 may not have teeth to form a closed frequency selective decoated grid portion. This means that at the boundary of the frequency selective decoated grid portion, the decoated grid may be different and not have teeth because it is not a connecting area, thereby minimizing the possibility of visible decoated portions and blending the frequency selective decoated grid portions.

[0117] With the present invention, this overly bright area is less visible or even invisible to the eye because the connection points are not aligned, so the eye only sees other points spread over a large area, and not a line made up of aligned connection points as in the prior art.

[0118] An embodiment according to the second aspect of the invention provides a method for removing a coating from a glazing unit according to the first aspect of the invention.

[0119] As shown in Figure 8, the method includes step B (800) of forming at least one frequency-selective uncoated grid portion (30) with a coating system. Step B includes the following substeps: Substep B1 (801) of forming a first decoated grid having, at least in connection regions, a decoated region in the form of grid lines arranged in a mesh, the first decoated grid including a rake design having at least one missing tooth. Substep B2 (802) of forming a second decoated grid having a decoated area in the form of grid lines arranged in a mesh pattern at least in a connection region, the second decoated grid including a rake design, and the first decoated grid being connected to the second decoated grid in the connection region. Preferably, the rake design of the second decoated grid has at least one missing tooth, at least in the connection region.

[0120] To accelerate the decoating step, especially for large frequency selective decoated grid portions, the decoated grid is formed using a laser beam directed with a galvo head, and then the laser head and / or glazing unit is moved so that the laser head is in front of the next area to be decoated.

[0121] Preferably, to optimize time while limiting displacement, a patchwork of frequency selective decoated grid portions is fabricated by fabricating the same row or column of decoated grid at a time, then the adjacent row or column, etc.

[0122] Depending on the size of the frequency selective decoated grid portions, the size of the decoated grid is adjusted, i.e. the decoated grid in the last and / or first row and / or last and / or first column has a different size from the other decoated grids, so that the size of the frequency selective decoated grid portions is less visible.

[0123] As shown in Figure 8, the coating removal step can occur in a factory. Step 700 involves providing a glazing panel, for example, by conveyor. Coating removal 800 is then performed in the factory to form a partially decoated glazing unit. The method can include step 900 of attaching the partially decoated glazing unit to a stationary object, for example, a building, or to a moving object, for example, a vehicle or train.

[0124] As shown in Figure 9, the coating removal step can be performed in-situ by using a mobile coating removal device. The term "in-situ" means that the glazing unit is already attached to a stationary object, such as a building, or a moving object, such as a vehicle or train. The coating removal device is moved to the front of the already attached glazing unit (701). The coating removal step 800 is performed in-situ, which means that the glazing unit remains attached during the coating removal step. The coating removal device is then moved to another glazing unit or for storage (901).

[0125] This method allows for the rapid fabrication of larger frequency selective ablated grid portions, and indeed, the patchwork arrangement of ablated grids connected end to edge allows for the fabrication of larger frequency selective ablated grid portions, particularly when the ablated grids are fabricated by a coating removal apparatus that uses a galvo head to direct a laser designed to remove the coating from the coating system.

[0126] In a third aspect, the present invention provides a coating removal apparatus for removing a coating from a glazing unit including a glazing panel including a glass sheet having low reflectivity to RF radiation and a coating system having high reflectivity to RF radiation disposed on the glass sheet, by the method according to the second aspect of the present invention.

[0127] Coating removal may be performed by laser ablation, with the spacing of the slits, such as the ablated lines, being selected to provide selectivity at the desired frequency, for which the coating removal device includes a laser head using a laser that is / will be focused on the coating system.

[0128] The coating removal device may be fixed on and / or around the glazing unit, for example to a frame, bodywork, wall, etc. that surrounds the glazing unit.

[0129] The coating removal device can be installed in front of the glazing unit for coating removal.

[0130] Such coating removal devices are described in WO2015050762, WO2022112532, WO2021165064, WO2021165065, WO2021239603, WO2022079225, WO2022112530, WO2022112529, and WO2022112521.

[0131] It should be understood that any other apparatus capable of removing a coating using the method according to the second aspect of the invention and / or providing a glazing unit according to the first aspect may be used.

[0132] The present invention makes it possible to use these different aspects to obtain a glazing unit comprising at least one frequency selective decoated grid portion, which is made up of a patchwork of decoated grids that is less visible and at the same time optimizes its decoating time.

Claims

1. a glazing panel comprising a glass sheet (1) with low reflectivity to RF radiation; - a coating system (2) that is highly reflective to RF radiation and placed on the glass sheet; at least one frequency-selective decoated grid portion (3) on said coating system, wherein said at least one frequency-selective decoated portion comprises a first decoated grid (31) and a second decoated grid (32), said first decoated grid and said second decoated grid each having a decoated area in the form of grid lines arranged in a mesh, said first decoated grid being connected to said second decoated grid at a connection area (51); A glazing unit (100) comprising: At least in the connection region, the first decoated grid includes a rake design having at least one missing tooth (321); and At least in the connection region, the second decoated grid includes a rake design. A glazing unit (100) characterized by:

2. 2. The glazing unit of claim 1, wherein at least in the connection region, the rake design of the second decoated grid has at least one missing tooth (321).

3. 3. A glazing unit according to claim 1, wherein in the connection region, the connection between the first de-coated grid and the second de-coated grid is made via at least one tooth of the rake design of the first de-coated grid and / or via at least one tooth of the rake design of the second de-coated grid, and wherein the at least one tooth of the rake design of the first de-coated grid is in contact with or has an overlapping portion O1 with the second de-coated grid and / or the at least one tooth of the rake design of the second de-coated grid is in contact with or has an overlapping portion O2 with the first de-coated grid.

4. A glazing unit as described in claim 3, wherein the overlap portion O1 is 0 mm to 0.4 mm, preferably 0 mm to 0.2 mm, more preferably 0 mm to 0.1 mm.

5. A glazing unit as described in claim 3 or 4, wherein the overlap portion O2 is 0 mm to 0.4 mm, preferably 0 mm to 0.2 mm, more preferably 0 mm to 0.1 mm.

6. A glazing unit according to any one of claims 1 to 5, wherein the grid lines form squares and / or rectangles.

7. 7. A glazing unit as described in any one of claims 1 to 6, wherein in the connection region, the rake design of the first de-coated grid matches the rake design of the second de-coated grid to form a closed grid.

8. 8. A glazing unit as described in any one of claims 1 to 7, wherein in the connection region, the rake design of the first de-coated grid is complementary to and matches opposite the rake design of the second de-coated grid, so that together they form a complete closed grid.

9. 9. A glazing unit as claimed in any one of claims 1 to 8, wherein the first decoated grid is connected to the second decoated grid by more than 50% of the teeth of the rake design of the first decoated grid, preferably the first decoated grid is connected to the second decoated grid by more than 80% of the teeth of the rake design of the first decoated grid, and more preferably the first decoated grid is connected to the second decoated grid by more than 90% of the teeth of the rake design of the first decoated grid.

10. 10. A glazing unit as claimed in any one of claims 1 to 9, wherein the first decoated grid is connected to the second decoated grid by more than 50% of the teeth of the rake design of the second decoated grid, preferably the first decoated grid is connected to the second decoated grid by more than 80% of the teeth of the rake design of the second decoated grid, and more preferably the first decoated grid is connected to the second decoated grid by more than 90% of the teeth of the rake design of the second decoated grid.

11. 11. A glazing unit according to any one of claims 1 to 10, wherein the at least one frequency selective decoated grid portion further comprises a third decoated grid having a decoated area in the form of grid lines arranged in a mesh, the third decoated grid being connected to the first decoated grid at a connection area (53), and at least in the connection area (53), the third decoated grid comprising a rake design with at least one missing tooth.

12. 12. The glazing unit of claim 11, wherein the at least one frequency-selective decoated grid portion further comprises a fourth decoated grid having a decoated region in the form of grid lines arranged in a mesh, the fourth decoated grid being connected to the second decoated grid at a connection region (53), and at least in the connection region (53), the third decoated grid comprising a rake design having at least one missing tooth, and the fourth decoated grid being connected to the third decoated grid at a connection region (53), and at least in the connection region (53), the fourth decoated grid comprising a rake design having at least one missing tooth.

13. A method for removing a coating from a glazing unit including a glazing panel including a glass sheet (10) having low reflectivity to RF radiation and a coating system (20) having high reflectivity to RF radiation disposed on the glass sheet, the method comprising a step B (800) of forming at least one frequency selective decoated grid portion (30) on the coating system, the step B comprising: Step B1 (801) of forming a first decoated grid having decoated regions in the form of grid lines arranged in a mesh; Step B2 (802) of forming a second decoated grid having decoated regions in the form of grid lines arranged in a mesh; Including, the first uncoated grid is connected to the second uncoated grid at a connection region; at least in the connection region, the first decoated grid includes a rake design having at least one missing tooth; and At least in the connection region, the second decoated grid includes a rake design. A method characterized by:

14. A coating removal device that removes a coating from a glazing unit that includes a glazing panel including a glass sheet (10) with low reflectivity to RF radiation and a coating system (20) with high reflectivity to RF radiation disposed on the glass sheet, using the method of claim 13.

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