WO2021209433A1

WO2021209433A1 - Pane having electrically heatable communication window for sensors and camera systems

Info

Publication number: WO2021209433A1
Application number: PCT/EP2021/059530
Authority: WO
Inventors: Stephan GILLESSEN; Andreas NOSITSCHKA; Stefan Droste; Klaus WEISSBORN
Original assignee: Saint-Gobain Glass France
Priority date: 2020-04-15
Filing date: 2021-04-13
Publication date: 2021-10-21
Also published as: CN114271026A

Abstract

The present invention relates to a pane (100) having an electrically heatable communication window (80), at least comprising: - a first pane (1) having a surface (III), - at least one electrically conductive, transparent coating (3), which is applied at least to part of the surface (III) and has at least two coating-free zones (8.1, 8.2), wherein in each case a heating conductor (12) from the coating (3) is disposed between two coating-free zones (8, 8.1, 8.2), and wherein at least two bus bars (5.1, 5.2) for connecting to a voltage source (14) are connected to the heating conductor (3) such that a current path (11) for a heating current is formed between the bus bars (5.1, 5.2).

Description

Disc with electrically heated communication window for sensors and

Camera systems

The invention is in the field of panes with communication windows, in particular for sensors and camera systems, a method for their production and their use.

Vehicles, airplanes, helicopters and ships are increasingly equipped with various sensors or camera systems. Examples are camera systems such as video cameras, night vision cameras, residual light amplifiers, laser range finders or passive infrared detectors. Vehicle identification systems are also increasingly being used for toll collection, for example.

Camera systems can use light in the ultraviolet (UV), visible (VIS) and infrared wavelength range (IR). This means that objects, vehicles and people can be precisely identified even in poor weather conditions, such as darkness and fog. These camera systems can be placed in motor vehicles behind the windshield in the passenger compartment. In this way, they also offer the possibility of recognizing dangerous situations and obstacles in good time, even in traffic.

Because of their sensitivity to the effects of the weather or winds, such sensors must in all cases be protected by panes that are transparent to radiation. To ensure that the optical sensors function optimally, clean and fog-free windows are essential. Fogging and icing significantly hinder the functionality, as they significantly reduce the transmission of electromagnetic radiation. While wiping systems can be used for water droplets and dirt particles, these are usually not sufficient in the case of icing. This requires systems that, if necessary, heat up the pane segment assigned to the sensor at least for a short time and thus enable uninterrupted use.

Panes increasingly have full-surface, electrically conductive coatings that are transparent to visible light, which, for example, protect interiors from overheating due to sunlight or cooling down or cause the pane to be heated in a targeted manner when an electrical voltage is applied. The discs with electric However, conductive, transparent coatings are not suitable as transparent protective panes for sensors or camera systems, since information-carrying radiation is not sufficiently transmitted through the coating. The panes are therefore usually stripped of localized coating and form a communication window for the sensors and camera systems. Such disks are known, for example, from WO 2011/069901 A1, WO 2015/071673 A1, US 2016/0374150 A1 or WO 2019/137674 A1.

In addition, the pane can have an electrical heating function. Composite panes are known which have a transparent, electrically conductive coating on an inside surface of one of the individual panes. An external voltage source can be used to conduct an electrical current through the electrically conductive coating, which heats the coating and thus the pane. WO2012 / 052315 A1 or EP 2 947957 A1 disclose, for example, such a heatable, electrically conductive metal-based coating.

The electrical contacting of the electrical heating layer is typically made via bus bars, as is known from US 2007/0020465 A1. The bus bars consist, for example, of a printed and burned-in silver paste. The bus bars typically run along the top and bottom edges of the disk. The bus bars collect the current that flows through the electrically conductive coating and direct it to external supply lines that are connected to a voltage source.

Since no direct heating can take place in the coating-free area of the communication window, this area must be made heatable by additional heating conductors, for example made of thin metal wires or thin conductors made of printed and burnt-in silver paste. Such opaque heating conductors impair the transmission through the window and are unsuitable for high-quality sensors and sophisticated camera systems, such as those required for modern traffic sign recognition or autonomous driving (so-called vision-based driver assistance systems, FAS or Advanced Driver Assistance Systems, ADAS). Alternatively, a transparent, electrically conductive coating can be used as the heating area, as is known from DE 102012 018001 A1 or US 2012/0103961 A1. The object of the present invention is to provide an improved pane with an electrically heatable communication window, which can be heated quickly and has little adverse effect on the optical properties of sensors and camera systems.

The object of the present invention is achieved according to the invention by a disk according to claim 1. Preferred embodiments emerge from the subclaims.

The pane according to the invention with an electrically heatable communication window comprises at least the following features:

- a first disc with a surface,

- At least one electrically conductive, transparent coating which is applied to at least part of the surface and has at least two coating-free zones, wherein

- There is a heating conductor between the coating-free zones, which consists of the coating, and

- At least two busbars provided for connection to a voltage source, which are connected to the heating conductor in such a way that a current path for a heating current is formed between the busbars.

The current path is in particular led through the areas of the heating conductors provided with the electrically conductive, transparent coating.

The heating conductor advantageously consists of an area of the coating, i.e. it consists of a section of the coating between the coating-free zones.

The communication window contains at least two coating-free zones. This means that the coating-free zone is completely or partially surrounded by the coating. The coating-free zone can in particular border on an edge region of the communication window which is formed by a coating-free dividing line. Panes with electrically heatable communication windows usually have opaque heating structures, for example made of thin metal wires or thin conductors made of printed and burnt-in silver paste. Such opaque heating conductors worsen the transmission through the pane and are unsuitable for high-quality sensors and sophisticated camera systems.

The invention is based on the knowledge that a sufficient heating power can be achieved by heating conductors from narrow areas of an electrically conductive, transparent coating and at the same time the transparent heating conductors only insignificantly impair the optical view of the optical sensors or camera systems. This is due in particular to the fact that the depth of field of the optical sensors or camera systems is optimized for longer distances and the thin and transparent heating conductors in the camera window are at a different distance from them. In combination with the transparent properties of the heating conductors, this only leads to a very slight impairment of the view in the spectral range used by the camera systems and optical sensors.

The invention is all the more effective, the larger the coating-free zones and the smaller the width of the heating conductors, with an optimization between the narrow width of the heating conductors and sufficient conductivity and thus sufficient heating power being achieved.

In an advantageous embodiment, the communication window according to the invention has at least two, preferably at least three, particularly preferably at least four and even more preferably at least five coating-free zones. In particular, the communication window according to the invention has exactly two, exactly three, exactly four, exactly five, exactly six, exactly seven, exactly eight, exactly nine or exactly ten coating-free zones. A heating conductor, which consists of the coating, is advantageously arranged between two coating-free zones in each case.

The heating conductors are advantageously designed in an electrical parallel circuit, ie the coating from which the heating conductors consist is arranged and provided with coating-free areas that the heating conductors are connected in electrical parallel circuit and when a voltage is applied to the busbars, current flows through them in parallel. In a further advantageous embodiment of the invention, the heating conductors have a constant width b. They are preferably web-shaped and in particular rectangular. The heating conductors must be made sufficiently thin in order to impair the view of the pane as little as possible. In a further advantageous embodiment of the pane according to the invention, the width of the width b of the heating conductors is from 0.1 mm to 1.5 mm, preferably from 0.1 mm to 0.6 mm and particularly preferably from 0.20 mm to 0.45 mm . Such heating conductors made of a transparent coating have the particular advantage that they do not or only very slightly impair the view through the pane.

In a further advantageous embodiment of the pane according to the invention, the coating-free zones are designed to be rectangular. The coating-free zones advantageously have a width B of 5 mm to 25 mm, preferably 10 mm to 20 mm and / or a length L of 1 cm to 20 cm, preferably 3 cm to 7 cm. This makes it possible to achieve a particularly advantageous improvement in the view through the communication window.

In an advantageous embodiment of a pane according to the invention, the area of the communication window (and thus the electrically conductive, transparent coating and the busbars) is partially and preferably completely separated galvanically and / or materially from the surrounding coating by a coating-free separating line. The width d of the dividing line is preferably from 30 μm to 200 μm and particularly preferably from 70 μm to 140 μm. Such a dividing line allows the electrical structures within the communication window to be isolated from the electrically conductive, transparent coating in the vicinity of the communication window without short circuits.

Regardless of an IR-reflecting effect of the electrically conductive, transparent coating, the coating, which is galvanically separated from the communication window, can also be used in the vicinity to heat the rest of the pane. For this purpose, at least two further bus bars provided for connection to the voltage source or to a further voltage source are preferably connected to the coating surrounding the communication window in such a way that a current path for a heating current is formed between the further bus bars. In a particularly preferred embodiment, the electrical current of the current path between the bus bars, which connect the heating conductors to one another, and the electrical current of the current path between the bus bars, which connect the coating surrounding the communication window, can be controlled independently of one another.

The width of the bus bars inside and, if appropriate, outside the communication window is preferably from 2 mm to 30 mm, particularly preferably from 4 mm to 20 mm and in particular from 10 mm to 20 mm. Thinner busbars lead to an electrical resistance that is too high and thus to excessive heating of the busbar during operation. Furthermore, thinner bus bars are difficult to manufacture using printing techniques such as screen printing. Thicker bus bars require an undesirably high amount of material. Furthermore, they lead to excessive and unaesthetic restriction of the viewing area of the pane. The length of the busbar depends on the expansion of the heating conductor or the area to be heated. In the case of a busbar, which is typically in the form of a strip, the longer of its dimensions is referred to as the length and the shorter of its dimensions is referred to as the width.

If the coating is also used for heating outside the communication window, typically further (third and fourth) busbars are preferably arranged along a side edge on the electrically conductive, transparent coating and in particular run approximately parallel to one another. The length of the busbar is typically essentially the same as the length of the side edge of the electrically conductive, transparent coating, but it can also be slightly larger or smaller. It is also possible for more than two bus bars to be arranged on the electrically conductive coating, preferably in the edge region along two opposite side edges of the electrically conductive, transparent coating. It is also possible for more than two bus bars to be arranged on the electrically conductive, transparent coating, for example around two or more independent heating fields.

In an advantageous embodiment, the bus bars according to the invention are designed as a printed and burned-in conductive structure. The printed busbars preferably contain at least one metal, a metal alloy, a Metal compound and / or carbon, particularly preferably a noble metal and in particular silver. The printing paste preferably contains metallic particles, metal particles and / or carbon and in particular noble metal particles such as silver particles. The electrical conductivity is preferably achieved by the electrically conductive particles. The particles can be in an organic and / or inorganic matrix such as pastes or inks, preferably as a printing paste with glass frits.

The layer thickness of the printed busbars is preferably from 5 pm to 40 pm, particularly preferably from 8 pm to 20 pm and very particularly preferably from 8 pm to 12 pm. Printed busbars with these thicknesses are technically easy to implement and have an advantageous current-carrying capacity.

The specific resistance p _{a of} the busbars is preferably from 0.8 pOhnvcm to 7.0 pOhnvcm and particularly preferably from 1.0 pOhnvcm to 2.5 pOhnvcm. Bus bars with specific resistances in this area are technically easy to implement and have an advantageous current-carrying capacity.

Alternatively, the busbar can also be designed as a strip of an electrically conductive film. The busbar then contains, for example, at least aluminum, copper, tinned copper, gold, silver, zinc, tungsten and / or tin or alloys thereof. The strip preferably has a thickness of 10 μm to 500 μm, particularly preferably 30 μm to 300 μm. Bus bars made of electrically conductive foils with these thicknesses are technically easy to implement and have an advantageous current-carrying capacity. The strip can be connected in an electrically conductive manner to the electrically conductive structure, for example via a solder mass, via an electrically conductive adhesive or by direct application.

The pane according to the invention comprises a first pane on which an electrically conductive, transparent coating is arranged. Depending on the material of the coating, it can be advantageous to protect the coating with a protective layer, for example a lacquer, a polymer film and / or a second pane.

In an advantageous embodiment of the pane according to the invention, the surface of the first pane is on which the electrically conductive, transparent coating is arranged, is flatly connected to a second pane via a thermoplastic intermediate layer

In principle, all electrically insulating substrates which are thermally and chemically stable and dimensionally stable under the conditions of manufacture and use of the pane according to the invention are suitable as the first and optionally the second pane.

The first pane and / or the second pane preferably contain glass, particularly preferably flat glass, float glass, quartz glass, borosilicate glass, soda-lime glass, or clear plastics, preferably rigid clear plastics, in particular polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, polystyrene, polyamide , Polyester, polyvinyl chloride and / or mixtures thereof. The first pane and / or the second pane are preferably transparent, in particular for the use of the pane as a windshield or rear pane of a vehicle or other uses in which a high level of light transmission is desired. Transparent in the context of the invention is then understood to mean a pane that has a transmission in the visible spectral range of greater than 70%. For windows that are not in the driver's field of vision relevant to traffic, for example for roof windows, the transmission can also be much lower, for example greater than 5%.

The thickness of the pane can vary widely and thus be perfectly adapted to the requirements of the individual case. Panes with the standard thicknesses of 1.0 mm to 25 mm, preferably 1.4 mm to 2.5 mm for vehicle glass and preferably 4 mm to 25 mm for furniture, appliances and buildings, in particular for electric radiators, are preferably used. The size of the disk can vary widely and depends on the size of the use according to the invention. The first pane and optionally the second pane have areas of 200 cm ² to 20 m ^{2, which are} common in vehicle construction and architecture, for example.

The disk can have any three-dimensional shape. The three-dimensional shape preferably has no shadow zones, so that it can be coated, for example, by cathode sputtering. The substrates are preferably planar or slightly or strongly curved in one direction or in several directions of space. In particular, planar substrates are used. The discs can be colorless or colored. Several panes are connected to one another by at least one intermediate layer. The intermediate layer preferably contains at least one thermoplastic, preferably polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) and / or polyethylene terephthalate (PET). The thermoplastic intermediate layer can also, for example, polyurethane (PU), polypropylene (PP), polyacrylate, polyethylene (PE), polycarbonate (PC), polymethyl methacrylate, polyvinyl chloride, polyacetate resin, casting resins, acrylates, fluorinated ethylene propylenes, polyvinyl fluoride and / or ethylene Tetrafluoroethylene, or copolymers or mixtures thereof. The thermoplastic intermediate layer can be formed by one or also by several thermoplastic films arranged one above the other, the thickness of a thermoplastic film preferably being from 0.25 mm to 1 mm, typically 0.38 mm or 0.76 mm.

In a composite pane according to the invention comprising a first pane, an intermediate layer and a second pane, the electrically conductive, transparent coating can be applied directly to the first pane or can be applied to a carrier film or to the intermediate layer itself. The first disk and the second disk each have an inside surface and an outside surface. The inside surfaces of the first and second panes face one another and are connected to one another via the thermoplastic intermediate layer. The outside surfaces of the first and second panes face away from each other and from the thermoplastic intermediate layer. The electrically conductive coating is applied to the inside surface of the first pane. Of course, a further electrically conductive coating can also be applied to the inside surface of the second pane. The outside surfaces of the panes can also have coatings. The terms “first pane” and “second pane” are chosen to distinguish the two panes in a composite pane according to the invention. The terms do not make any statements about the geometric arrangement. If the pane according to the invention is intended, for example, to separate the interior from the external environment in an opening, for example of a vehicle or a building, then the first pane can face the interior or the external environment. Electrically conductive, transparent coatings according to the invention are known, for example, from DE 202008017611 U1, EP 0847 965 B1 or WO20 12/052315 A1. They typically contain one or more, for example two, three or four, electrically conductive, functional layers. The functional layers preferably contain at least one metal, for example silver, gold, copper, nickel and / or chromium or a metal alloy. The functional layers particularly preferably contain at least 90% by weight of the metal, in particular at least 99.9% by weight of the metal. The functional layers can consist of the metal or the metal alloy. The functional layers particularly preferably contain silver or an alloy containing silver. Such functional layers have a particularly advantageous electrical conductivity with a simultaneous high transmission in the visible spectral range. The thickness of a functional layer is preferably from 5 nm to 50 nm, particularly preferably from 8 nm to 25 nm. In this range for the thickness of the functional layer, an advantageously high transmission in the visible spectral range and a particularly advantageous electrical conductivity are achieved.

At least one dielectric layer is typically arranged between two adjacent functional layers of the coating. A further dielectric layer is preferably arranged below the first and / or above the last functional layer. A dielectric layer contains at least one single layer made 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 a plurality of individual layers, for example individual layers of a dielectric material, smoothing layers, adaptation layers, blocker layers and / or antireflection layers. The thickness of a dielectric layer is, for example, from 10 nm to 200 nm.

This layer structure is generally obtained through a sequence of deposition processes that are carried out using a vacuum process such as magnetic field-assisted cathode sputtering.

Further suitable electrically conductive coatings preferably contain indium tin oxide (ITO), fluorine-doped tin oxide (Sn0 ₂ : F) or aluminum-doped zinc oxide (ZnO: Al). The electrically conductive, transparent coating can in principle be any coating that is to be electrically contacted and has sufficient transparency. If the pane according to the invention is intended to enable transparency, as is the case, for example, with panes in the window area, the electrically conductive coating is preferably transparent. The electrically conductive coating according to the invention is preferably transparent for electromagnetic radiation, particularly preferably for electromagnetic radiation with a wavelength of 300 to 1,300 nm and in particular for visible light.

In an advantageous embodiment, the electrically conductive coating is a layer or a layer structure of several individual layers with a total thickness of less than or equal to 2 μm, particularly preferably less than or equal to 1 μm.

An advantageous electrically conductive coating according to the invention has a sheet resistance of 0.4 ohm / square to 10 ohm / square. In a particularly preferred embodiment, the electrically conductive coating according to the invention has a sheet resistance of 0.5 ohm / square to 1 ohm / square. Coatings with such surface resistances are particularly suitable for heating vehicle windows with typical on-board voltages of 12 V to 48 V or for electric vehicles with typical on-board voltages of up to 500 V.

The electrically conductive, transparent coating can extend over the entire surface of the first pane. Alternatively, however, the electrically conductive, transparent coating can also extend only over part of the surface of the first pane. The electrically conductive, transparent coating extends preferably over at least 50%, particularly preferably over at least 70% and very particularly preferably over at least 90% of the inside surface of the first pane. In addition to the coating-free zones, the electrically conductive, transparent coating can also have one or more coating-free areas.

In an advantageous embodiment of a pane according to the invention as a composite pane, the inside surface of the first pane has a circumferential edge area with a width of 2 mm to 50 mm, preferably 5 mm to 20 mm, which is not provided with the electrically conductive, transparent coating. The electrically conductive, transparent coating then has none Contact with the atmosphere and is advantageously protected from damage and corrosion inside the pane by the thermoplastic intermediate layer.

The bus bars are electrically contacted by one or more supply lines. The supply line is preferably designed as a flexible foil conductor (flat conductor, flat strip conductor). This is understood to mean an electrical conductor whose width is significantly greater than its thickness. Such a foil conductor is, for example, a strip or tape containing or consisting of copper, tinned copper, aluminum, silver, gold or alloys thereof. The foil conductor has, for example, a width of 2 mm to 16 mm and a thickness of 0.03 mm to 0.1 mm. The film conductor can have an insulating, preferably polymeric sheathing, for example based on polyimide. Foil conductors, which are suitable for contacting electrically conductive coatings in panes, only have a total thickness of, for example, 0.3 mm. Such thin film conductors can be embedded between the individual panes in the thermoplastic intermediate layer without difficulty. Several conductive layers that are electrically isolated from one another can be located in a foil conductor strip.

Alternatively, thin metal wires can also be used as an electrical lead. The metal wires contain in particular copper, tungsten, gold, silver or aluminum or alloys of at least two of these metals. The alloys can also contain molybdenum, rhenium, osmium, iridium, palladium or platinum.

In an advantageous embodiment of the invention, the electrical lead is connected to a contact strip, for example by means of a solder compound or an electrically conductive adhesive. The contact strip is then connected to the busbar. In the context of the invention, the contact strip is an extension of the supply line, so that the connecting surface between the contact strip and the bus bar is to be understood as the contact area according to the invention, from which the distance a runs in the direction of extent of the bus bar. The contact strip preferably contains at least one metal, particularly preferably copper, tinned copper, silver, gold, aluminum, zinc, tungsten and / or tin. This is particularly advantageous with regard to the electrical conductivity of the contact strip. The contact strip can also contain alloys, which preferably contain one or more of the elements mentioned and optionally further elements, for example brass or bronze. The contact strip is preferably designed as a strip of a thin, electrically conductive film. The thickness of the contact strip is preferably from 10 μm to 500 μm, particularly preferably from 15 μm to 200 μm, very particularly preferably from 50 μm to 100 μm. Films with these thicknesses are technically simple to manufacture and readily available and also have an advantageously low electrical resistance.

The invention further comprises a method for producing a pane according to the invention, at least comprising:

(a) applying an electrically conductive, transparent coating to a surface of a pane with at least two coating-free zones and a heating conductor arranged between them, which is formed from a region of the coating, and

(b) Application of at least two bus bars provided for connection to a voltage source, which bus bars are connected to the heating lead in such a way that a current path for a heating current is formed between the bus bars.

The application of the electrically conductive coating of the electrically conductive, transparent coating in method step (a) can be carried out by methods known per se, preferably by magnetic field-assisted cathode sputtering. This is particularly advantageous with regard to a simple, fast, inexpensive and uniform coating of the first pane. The electrically conductive coating can, however, also be applied, for example, by vapor deposition, chemical vapor deposition (CVD), plasma-assisted gas phase deposition (PECVD) or by wet-chemical processes.

The first pane can be subjected to a temperature treatment during or after process step (a). The first pane with the electrically conductive coating is heated to a temperature of at least 200.degree. C., preferably at least 300.degree. The temperature treatment can serve to increase the transmission and / or to reduce the sheet resistance of the electrically conductive coating.

The first pane can be bent according to process step (a), typically at a temperature of 500 ° C to 700 ° C. Since it is technically easier to coat a flat pane, this procedure is advantageous if the first pane should be bent. Alternatively, however, the first pane can also be bent before or during method step (a), for example if the electrically conductive coating is not suitable for withstanding a bending process without damage.

The busbar is preferably applied in process step (b) by printing and baking an electrically conductive paste in a screen printing process or in an inkjet process. Alternatively, the busbar can be applied to the electrically conductive coating as a strip of an electrically conductive film, preferably placed, soldered on or glued on.

In screen printing processes, the lateral shaping takes place by masking the fabric through which the printing paste with the metal particles is pressed. By suitably shaping the masking, for example, the width of the bus bar can be predefined and varied in a particularly simple manner.

The production (decoating) of individual coating-free zones in the electrically conductive coating is preferably carried out by a laser beam. Methods for structuring thin metal films are known, for example, from EP 2 200 097 A1 or EP 2 139049 A1. The width of the stripping is preferably 10 pm to 1000 pm, particularly preferably 30 pm to 200 pm and in particular 70 pm to 140 pm. In this area, a particularly clean and residue-free stripping takes place using the laser beam. The stripping by means of a laser beam is particularly advantageous, since the stripped lines are optically very inconspicuous and only slightly impair the appearance and transparency. The stripping of a line with a width that is wider than the width of a laser cut is carried out by repeatedly tracing the line with the laser beam. The process duration and the process costs therefore increase as the line width increases. Alternatively, the stripping can be carried out by mechanical removal as well as by chemical or physical etching.

An advantageous development of the method according to the invention comprises at least the following further steps:

(c) placing a thermoplastic intermediate layer on the coated surface of the first pane and placing a second pane on the thermoplastic intermediate layer and (d) joining the first pane and the second pane via the thermoplastic intermediate layer.

In method step (c), the first pane is arranged in such a way that that of its surfaces which is provided with the electrically conductive, transparent coating faces the thermoplastic intermediate layer. The surface thereby becomes the inside surface of the first pane.

The thermoplastic intermediate layer can be formed by a single or also by two or more thermoplastic films which are arranged one above the other in terms of area.

The joining of the first and second panes in process step (d) is preferably carried out under the action of heat, vacuum and / or pressure. Methods known per se for producing a disk can be used.

For example, so-called autoclave processes can be carried out at an elevated pressure of about 10 bar to 15 bar and temperatures of 130 ° C. to 145 ° C. for about 2 hours. Vacuum bag or vacuum ring processes known per se work, for example, at around 200 mbar and 80 ° C to 110 ° C. The first disk, the thermoplastic intermediate layer and the second disk can also be pressed into a disk in a calender between at least one pair of rollers. Systems of this type are known for the production of panes and normally have at least one heating tunnel in front of a press shop. The temperature during the pressing process is, for example, from 40 ° C to 150 ° C. Combinations of calender and autoclave processes have proven particularly useful in practice. Alternatively, vacuum laminators can be used. These consist of one or more heatable and evacuable chambers in which the first pane and the second pane are laminated within, for example, about 60 minutes at reduced pressures of 0.01 mbar to 800 mbar and temperatures of 80 ° C to 170 ° C.

The invention further includes the use of the pane according to the invention with electrical contact in buildings, in particular in the access area, window area, roof area or facade area, as a built-in part in furniture and equipment, in means of transport for traffic in the country, in the air or to Water, especially in trains, ships and motor vehicles, for example as a windshield, rear window, side window and / or roof window. The use includes optical sensors and camera systems, in particular for vision-based driver assistance systems, FAS or Advanced Driver Assistance Systems, ADAS, the beam path of which runs through the communication window.

The invention is explained in more detail below with reference to a drawing and exemplary embodiments. The drawing is a schematic representation and is not true to scale. The drawing does not restrict the invention in any way.

Show it:

FIG. 1A shows a plan view of an embodiment of the pane according to the invention with an electrically heatable communication window,

FIG. 1B shows an enlarged illustration of the communication window from FIG. 1A,

Figure 1C is a cross-sectional view along the section line A-A 'through the pane of Figure 1A,

Figure 2 is a plan view of a further embodiment of the disc according to the invention and

FIG. 3 shows a flow diagram of an embodiment of the method according to the invention.

FIG. 1A shows a top view of an exemplary embodiment of a pane 100 according to the invention with an electrically heatable communication window 80. FIG. 1B shows an enlarged illustration of the communication window from FIG. 1A and FIG. 1C shows a cross section through the pane 100 according to the invention from FIG. 1A along the section line A-A '.

The pane 100 comprises a first pane 1 and a second pane 2, which are connected to one another via a thermoplastic intermediate layer 4. The window 100 is, for example, a vehicle window and in particular the windshield of a passenger car. The first pane 1 is provided, for example, to face the interior in the installed position. The first disk 1 and the second disk 2 are made of soda-lime glass. The thickness of the first disk 1 is, for example, 1.6 mm and the thickness of the second disk 2 is 2.1 mm. The thermoplastic intermediate layer 4 consists of polyvinyl butyral (PVB) and has a thickness of 0.76 mm. On the inside surface III of the first disc 1 is an electrically conductive, transparent coating 3 is applied. The electrically conductive, transparent coating 3 is a layer system which contains, for example, three electrically conductive silver layers which are separated from one another by dielectric layers. If a current flows through the electrically conductive, transparent coating 3, it is heated as a result of its electrical resistance and Joule heat generation. The electrically conductive, transparent coating 3 can therefore be used for active heating of the communication window 80.

The electrically conductive, transparent coating 3, 3 ‘extends, for example, over the entire surface III of the first pane 1 minus a circumferential, frame-shaped uncoated area with a width of 8 mm. The uncoated area is used for electrical insulation between the electrically conductive, transparent coating 3 and the vehicle body. The uncoated area is hermetically sealed by gluing with the intermediate layer 4 in order to protect the electrically conductive, transparent coating 3, 3 'from damage and corrosion.

The electrically conductive, transparent coating 3, 3 ‘is in this

Embodiment not used for the complete heating of the entire pane 100, but rather the IR-reflecting properties of the coating 3, 3 'are used, for example to protect the interior of the vehicle against solar radiation and to keep it cool. (For an embodiment of a completely heatable pane 100 see Figure 2.)

The communication window 80 is here, for example, surrounded by a coating-free separating line 9, which separates the coating 3 in the interior of the communication window 80 from a surrounding coating 3 materially and galvanically (that is, for direct currents). The dividing line 9 has, for example, a width d of 100 μm in which the coating 3 has been completely removed. The dividing line 9 is produced, for example, by laser structuring (laser ablation).

The electrically conductive, transparent coating 3 within the communication window 80 has six coating-free zones 8 in this example. Coated areas in the form of heating conductors 12 are arranged between the coating-free zones 8. The width b of the heating conductor 12 is here for example constant along the heating conductor 12 and constant in all intermediate areas. The width b here is preferably from 0.1 mm to 1.5 mm, particularly preferably from 0.1 mm to 0.6 mm, in particular from 0.20 mm to 0.45 mm and, for example, 0.25 mm or 0, 4 mm.

The coating-free zones 8 are produced, for example, by laser stripping (laser ablation) or other mechanical, physical or chemical structuring and removal processes.

The coating-free zones 8 in this example have a width B of 1 cm and a length L of 7 cm. Only the uppermost coating-free zone 8.3 is extended in sections to the dividing line 9 on its right-hand side in order to galvanically separate the coating 3 in the vicinity of the busbar 5.1 from the coating 3 in the vicinity of the busbar 5.2 and to create a short circuit between the busbars 5.1, 5.2 impede. Likewise, the lower, coating-free zone 8.4 is widened and, on its lower side, extends as far as the dividing line 9. This is also used for galvanic isolation and to avoid an undesired short circuit between the busbars 5.1, 5.2.

The communication window 80 is suitable for ensuring that a camera system 20 or other optical sensors can see through it. For this purpose, the camera window 10, that is to say the area of the optical beam path of the camera system 20 through the pane 100, is arranged completely within the electrically heatable area of coating-free zones 8 and heating conductors 12. Such an arrangement of coating-free zones 8 and narrow, transparent heating conductors 12 is visually barely noticeable for the camera system 20 and only slightly disturbs the view through the pane 100, which is particularly important for use in vehicles and camera systems 20 with high optical requirements.

For electrical contacting, a first busbar 5.1 is arranged on the left edge area and a further, second busbar 5.2 is arranged on the right edge area of the coating-free zones 8 or the heating conductor 12 on the electrically conductive, transparent coating 3. The bus bars 5.1, 5.2 contain, for example, silver particles and were applied using the screen printing process and then burned in. The length of the busbars 5.1, 5.2 corresponds approximately to the extent of the coating-free zones 8 including the heating conductor 12. If an electrical voltage is applied to the busbars 5.1 and 5.2, a uniform current flows through the heating conductors 12 between the busbars 5.1, 5.2, whereby the communication window 80 and in particular the sensor or camera window 10 is heated.

Each busbar 5.1, 5.2 is led to a connection area which is each provided with a connection or connecting conductor 7.1, 7.2 which connects the busbars 5.1, 5.2 to a voltage source 14. The connection lines 7.1, 7.2 can be designed as known foil conductors, which are electrically conductively connected to the busbar 5.1, 5.2 via a contact surface, for example by means of a solder, an electrically conductive adhesive or by simply resting and pressing inside the pane 100. The foil conductor contains, for example, a tinned copper foil with a width of 10 mm and a thickness of 0.3 mm. Connection cables connected to the voltage source 14 can pass over the foil conductors. The voltage source 14 provides, for example, an on-board voltage customary for motor vehicles, preferably from 12 V to 15 V and, for example, approximately 14 V. Alternatively, the voltage source 14 V can also have higher voltages, for example from 35 V to 45 V and in particular 42 V.

In the example shown, the busbars 5.1, 5.2 have a constant thickness of, for example, approximately 10 μm and a constant specific resistance of, for example, 2.3 pOhnvcm.

When a voltage is applied to the busbars 5.1, 5.2, an electric current flows through the heating conductors 12. By way of example, a current path 11 is shown here between the coating-free zones 8.1, 8.2. It goes without saying that a corresponding current path 11 is also established in the other heating conductors 12.

As is customary in glazing technology, the busbars 5.1, 5.2 and the connections as well as the connecting lines 7.1, 7.2 can be covered by an opaque paint layer known per se as a masking print (not shown here).

FIG. 2 shows a plan view of a further embodiment of a disk 100 according to the invention. The first disk 1, the second disk 2, the electrically conductive, The transparent coating 3 and the communication window 80 and the thermoplastic intermediate layer 4 are configured as in FIG. 1A.

In addition, the pane 100 according to FIG. 2 can also be electrically heated in the coating area 3 ', that is to say also outside the communication window 80. To make electrical contact with the coating 3 outside the communication window 80, a first bus bar 50.1 is arranged in the lower edge area and a further, second bus bar 50.2 is arranged in the upper edge area on the electrically conductive, transparent coating 3 ‘. The bus bars 50.1, 50.2 contain, for example, silver particles and were applied using the screen printing process and then burned in. The length of the busbars 50.1, 50.2 corresponds approximately to the extent of the electrically conductive, transparent coating 3 ‘.

If an electrical voltage is applied to the busbars 50.1 and 50.2, a uniform current flows (for example along the current path 110) through the electrically conductive, transparent coating 3 'between the busbars 50.1, 50.2. On each busbar 50.1, 50.2 there is a connection with a supply line approximately in the middle

70.1, 70.2 arranged. The connection 70.1, 70.2 is, for example, a film conductor known per se, which merges into a round cable. The connection 70.1, 70.2 is electrically conductively connected to the busbar 50.1, 50.2 via a contact surface, for example by means of a solder, an electrically conductive adhesive or by simply resting and pressing inside the pane 100. The foil conductor contains, for example, a tinned copper foil with a width of 10 mm and a thickness of 0.3 mm. The bus bars are via the electrical connections 70.1, 70.2

50.1, 50.2, for example, connected to the voltage source 14, which - as already stated - provides an on-board voltage customary for motor vehicles, preferably from 12 V to 15 V and, for example, approximately 14 V. Alternatively, the voltage source 14 V can also have higher voltages, for example from 35 V to 45 V and in particular 42 V. Alternatively, a further voltage source with the same or a different voltage than the voltage source 14 can be connected to the connections 70.1, 70.2.

In Table 1, simulation results on panes 100 according to the invention for different widths b of the heating conductors 12 are summarized.

Table 1

The windows 100 according to the invention simulated here according to FIGS. 1A, 1B and 1C with widths of the heating conductors 12 of 0.25 mm and 0.4 mm all show complete de-icing of the window 100 in the area of the camera window 10 within the required 10 minutes.

FIG. 3 shows a flow diagram of an exemplary embodiment of the method according to the invention for producing an electrically heatable pane 100.

The method according to the invention comprises the following steps:

S1: applying an electrically conductive, transparent coating 3 to a surface III of a pane 1 with at least two coating-free zones 8 and heating conductor 12 arranged between them, which is formed from a region of the coating 3, and

S2: Application of at least two bus bars 5.1, 5.2 provided for connection to a voltage source 14, which are connected to the heating conductor 12 in such a way that a current path 11 for a heating current is formed between the bus bars 5.1, 5.2. List of reference symbols:

1 first slice

2 second disc

3, 3 ‘(electrically conductive, transparent) coating

4 thermoplastic intermediate layer

5.1, 5.2, 50.1, 50.2 busbars

7.1, 7.2, 70.1, 70.2 connection 8, 8.1, 8.2, 8.3, 8.4 coating-free zone

9 dividing line

10 camera windows

11, 110 current path 12 heating conductor 14 voltage source 20 camera system 80 (electrically heatable) communication window 100 pane

Surface of the second disc 2

III surface of the first pane 1 b width of the heating conductor 12 d width of the dividing line 9

B Width of the coating-free zone 8

L Length of the coating-free zone 8

S1, S2 process step

Pa resistivity of the busbar 5, 50

A-A 'cutting line

Claims

1. Disc (100) with electrically heatable communication window (80), at least comprising:

- a first disc (1) with a surface (III),

- At least one electrically conductive, transparent coating (3) which is applied to at least part of the surface (III) and has at least two coating-free zones (8, 8.1, 8.2), wherein

- A heating conductor (12) from the coating (3) is present between the coating-free zones (8, 8.1, 8.2) and

- At least two busbars (5.1, 5.2) provided for connection to a voltage source (14), which are connected to the heating conductor (12) in such a way that a current path (11) for a heating current is formed between the busbars (5.1, 5.2).

2. pane (100) according to claim 1, wherein the communication window (80) has at least three, preferably at least four, particularly preferably at least five and in particular exactly three, four, five, six, seven, eight, nine or ten coating-free zones (8, 8.1, 8.2), between each of which a heating conductor (12) is arranged.

3. disc (100) according to claim 2, wherein the heating conductors (12) are formed in electrical parallel connection to one another.

4. disc (100) according to one of claims 1 to 3, wherein the heating conductor (12) has a constant width b and / or is web-shaped and preferably rectangular.

5. disc (100) according to one of claims 1 to 4, wherein the width b of the heating conductor (12) from 0.1 mm to 1.5 mm, preferably from 0.1 mm to 0.6 mm and particularly preferably from 0 , 20 mm to 0.45 mm.

6. Disc (100) according to one of claims 1 to 5, wherein the coating-free zones (8) are rectangular and preferably have a width B of 5 mm to 25 mm, preferably from 10 mm to 20 mm and / or a length L from 1 cm to 20 cm, preferably from 3 cm to 7 cm.

7. pane (100) according to one of claims 1 to 6, wherein the communication window (80) is completely separated galvanically and / or materially from the surrounding coating (3 ') by a coating-free dividing line (9) and the width d of the dividing line ( 9) is preferably from 30 pm to 200 pm and particularly preferably from 70 pm to 140 pm.

8. Disc (100) according to one of claims 1 to 7, wherein at least two busbars (50.1, 50.2) provided for connection to the voltage source (14) or to a further voltage source with the coating (3 ') surrounding the communication window (80) are connected in such a way that a current path (110) for a heating current is formed between the busbars (50.1, 50.2) and an electric current is preferably formed along the current path (11) between the busbars (5.1, 5.2) which the heating conductors (12) interconnect, and an electric current along the current path (110) between the busbars (50.1, 50.2), which connect the coating (3 ') surrounding the communication window (80), can be controlled independently of one another.

9. disc (100) according to any one of claims 1 to 8, wherein the busbars (5.1, 5.2, 50.1, 50.2) are designed as fired printing paste, which preferably contain metallic particles, metal particles and / or carbon particles and in particular silver particles and preferably have a specific resistance p _a of 0.8 pOhnvcm to 7.0 pOhnvcm and particularly preferably from 1.0 pOhnvcm to 2.5 pOhnvcm.

10. Disc (100) according to one of claims 1 to 9, wherein the surface (III) of the first disc (1) is connected flatly to a second disc (2) via a thermoplastic intermediate layer (4).

11. pane (100) according to one of claims 1 to 10, wherein the first pane (1) and / or the second pane (2) glass, preferably flat glass, float glass, quartz glass, borosilicate glass, soda-lime glass, or polymers, preferably polyethylene, Contains polypropylene, polycarbonate, polymethyl methacrylate and / or mixtures thereof.

12. Disc (100) according to one of claims 1 to 11, wherein the transparent, electrically conductive coating (3) has a sheet resistance of 0.4 ohms / square to 10 ohms / square and preferably from 0.5 ohms / square to 1 ohm / Square and / or silver (Ag), indium tin oxide (ITO), fluorine-doped tin oxide (SnC> 2: F) or aluminum-doped zinc oxide (ZnO: AI).

13. A method for producing a disk (100) according to any one of claims 1 to 12, at least comprising:

(a) Applying an electrically conductive, transparent coating (3) to a surface (III) of a pane (1) with at least two coating-free zones (8) and heating conductor (12) arranged between them, which is formed from a region of the coating (3) will, and

(b) Application of at least two busbars (5.1, 5.2) provided for connection to a voltage source (14), which are connected to the heating conductor (12) in such a way that a current path (11) for a Heating current is formed.

14. The method according to claim 13, wherein the coating-free zones (9) and / or the dividing line (9) are produced by laser structuring and in particular by laser ablation of the coating (3).

15. Use of the disc (100) according to one of claims 1 to 12 as a functional individual piece, as a built-in part in furniture, appliances and buildings, or as a disc in means of transport for traffic on land, in the air or on water, preferably as a windshield , Rear window, side windows or roof window of a motor vehicle, with optical sensors and camera systems (20), in particular for vision-based driver assistance systems, FAS or Advanced Driver Assistance Systems, ADAS, the beam path of which runs through the communication window.