CN114271026A

CN114271026A - Glass pane with an electrically heatable communication window for a sensor and a camera system

Info

Publication number: CN114271026A
Application number: CN202180001865.8A
Authority: CN
Inventors: S·吉莱森; A·诺西奇卡; S·德罗斯特; K·魏斯博恩
Original assignee: Saint Gobain Glass France SAS
Current assignee: Saint Gobain Glass France SAS
Priority date: 2020-04-15
Filing date: 2021-04-13
Publication date: 2022-04-01
Also published as: WO2021209433A1

Abstract

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

Description

Glass pane with an electrically heatable communication window for a sensor and a camera system

Technical Field

The invention is in the field of glass sheets with communication windows, in particular for sensors and camera systems, methods for manufacturing said glass sheets and uses thereof.

Background

Vehicles, aircraft, helicopters and ships are increasingly equipped with different sensors or camera systems. Examples are camera systems such as video cameras, night vision cameras, afterglow amplifiers, laser rangefinders or passive infrared detectors. For example, vehicle identification systems are also increasingly used for charging.

The camera system may use light in the Ultraviolet (UV), Visible (VIS) and infrared wavelength ranges (IR). So that objects, vehicles and persons can be accurately identified even under severe weather conditions such as darkness and smoke. These camera systems may be placed behind a windshield in the passenger compartment in a motor vehicle. The camera system thus also offers the possibility of timely recognition of dangerous situations and obstacles in road traffic.

However, due to their sensitivity to weather influences or to the flow of air in relation to driving, such sensors must in all cases be protected by a radiation-transparent glass plate. In order to ensure optimum functioning of the optical sensor, a clean and moisture-free glass plate is imperatively necessary. Moisture and ice formation significantly hinder the functional mode, since they significantly reduce the transmission of electromagnetic radiation. Wiping systems can be used for water droplets and dirt particles, which are often not sufficient in the case of ice formation. In this case, it is necessary to heat the glass sheet section assigned to the sensor at least temporarily when required and thus to be able to realize a system which can be used without interruption.

Glass panes increasingly have an overall electrically conductive and visible light-transparent coating which, for example, protects the interior from overheating or cooling by sunlight or causes a targeted heating of the glass pane when a voltage is applied. However, glass plates with an electrically conductive transparent cover are not suitable as transparent protective glass plates for sensors or camera systems, since the information-bearing radiation is not sufficiently transmitted through the cover. The glass plate is therefore usually de-coated locally to a limited extent and constitutes a communication window for the sensor and the camera system. Such glass sheets are known, for example, from WO 2011/069901 a1, WO 2015/071673 a1, US 2016/0374150 a1 or WO 2019/137674 a 1.

Further, the glass plate may have an electric heating function. Thus, composite glass sheets are known which have a transparent conductive coating on the inside surface of one of the individual glass sheets. An electric current can be conducted through the electrically conductive coating by an external voltage source, which heats the coating and thus the glass pane. For example, WO2012/052315 a1 or EP 2947957 a1 discloses such heatable electrically conductive metal-based coatings.

The electrical contacting of the electrical heating layer is typically done via a bus conductor as known from US 2007/0020465 a 1. For example, the bus conductor is composed of printed and fired silver paste. The bus conductors typically run along the upper and lower edges of the glass sheets. The bus conductors collect the current flowing through the conductive coating and conduct the current to external leads that are connected to a voltage source.

Since no direct heating can take place in the uncoated region of the communication window, this region must be heatable by means of additional heating conductors, which are, for example, composed of thin metal wires or of printed and calcined silver paste. Such opaque heating conductors deteriorate the transmission through the glass pane and are not suitable for Advanced sensors and demanding camera Systems (so-called vision-based Driver Assistance Systems, FAS or Advanced Driver Assistance Systems, ADAS) as are required, for example, for modern traffic sign recognition or autonomous driving. Alternatively, as is known from DE 102012018001 a1 or US 2012/0103961 a1, a transparent conductive coating may be used as the heating area.

Disclosure of Invention

The object of the present invention is to provide an improved glass pane having an electrically heatable communication window which can be heated rapidly and has little influence on the optical properties of the sensor and the camera system.

According to the invention, the object of the invention is achieved by a glass pane according to claim 1. Preferred embodiments emerge from the dependent claims.

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

-a first glass plate having a surface,

at least one electrically conductive transparent coating which is applied at least on a part of the surface and has at least two coating-free regions, wherein

Between the uncoated regions, in each case a heating conductor is present, which consists of a coating, and

at least two bus conductors provided for connection to a voltage source, which bus conductors are connected to the heating conductors such that a current path for the heating current is formed between the bus conductors.

The current path is in particular guided through the region of the heating conductor provided with the electrically conductive transparent coating.

Advantageously, the heating conductor is formed by a coated region, i.e. the heating conductor is formed by a coated section between the uncoated regions.

The communication window comprises at least two uncoated regions. This means that the uncoated zone is completely or partially surrounded by the coating. The uncoated region can in particular adjoin an edge region of the communication window, which is formed by an uncoated parting line.

Glass panes with electrically heatable communication windows usually have an opaque heating structure, which is composed, for example, of thin metal wires or of thin conductors made of printed and calcined silver paste. Such opaque heating conductors degrade transmission through the glass and are not suitable for advanced sensors and demanding camera systems.

The invention is based on the following recognition: that is, sufficient heating power can be achieved by the heating conductor consisting of a narrow region of the electrically conductive transparent coating, and at the same time the transparent heating conductor only insignificantly influences the optical transmission of the optical sensor or the camera system. This is dependent, in particular, on the fact that the depth of field of the optical sensor or the imaging system is optimized in view of the greater distance (auf weiter entrfnungen) and the thin, transparent heating conductor in the imaging window is at a different distance (dazu) from this. In combination with the transparent properties of the heating conductor, this results in only a very small influence on the transmission in the spectral range used by the camera system and the optical sensor.

The invention is more efficient, the larger the uncoated area and the smaller the width of the heating conductor, wherein an optimization is achieved between a small width of the heating conductor and a sufficient electrical conductivity and thus a sufficient heating power.

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 cladding-free regions. 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 cladding-free regions. The heating conductor formed by the coating is advantageously arranged between two respective uncoated regions.

The heating conductors are advantageously designed in an electrically parallel manner, i.e. the cladding arrangement forming the heating conductors is provided with a cladding-free region such that the heating conductors are connected in an electrically parallel manner and, when a voltage is applied to the busbar, flow in parallel with a current.

In a further advantageous embodiment of the invention, the heating conductor has a constant width b. The heating conductor is preferably designed as a bridge (foster mini) and is especially rectangular. The heating conductor must be made sufficiently thin to influence the perspective of the glass plate as little as possible. In a further advantageous embodiment of the glass pane according to the invention, the width b of the heating conductor is 0.1 mm to 1.5 mm, preferably 0.1 mm to 0.6 mm and particularly preferably 0.20 mm to 0.45 mm. Such a heating conductor consisting of a transparent coating has the particular advantage that it does not or only very slightly influence the transmission through the glass pane.

In a further advantageous embodiment of the glass pane according to the invention, the cladding-free region is rectangular. The uncoated zone advantageously has 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. A particularly advantageous improvement of the perspective through the communication window can thereby be achieved.

In an advantageous embodiment of the glass pane according to the invention, the region of the communication window (and thus the electrically conductive transparent coating and the bus conductor) is partially and preferably completely separated from the surrounding coating galvanic separation and/or material by a coating-free separation line. The width d of the separation line is preferably 30 μm to 200 μm and particularly preferably 70 μm to 140 μm. By means of such a separation line, the electrical structure within the communication window can be insulated from the conductive transparent coating in the environment of the communication window (sich) by itself and without short circuits.

Despite the IR-reflecting effect of the conductive transparent coating, the coating in the environment that is galvanically isolated from the communication window can also be used to heat the remaining glass plate. For this purpose, preferably at least two further bus conductors, which are provided for connection to the voltage source or to a further voltage source, are connected to the cladding surrounding the communication window, so that a current path for the heating current is formed between the further bus conductors.

In a particularly preferred embodiment, the current of the current path between the bus conductors connecting the heating conductors to one another and the current of the current path between the bus conductors connecting the cladding surrounding the communication window can be controlled independently of one another.

The width of the bus conductors within and, if appropriate, outside the communication window is preferably 2 mm to 30 mm, particularly preferably 4 mm to 20 mm and in particular 10 mm to 20 mm. The thinner bus conductors lead to an excessively high electrical resistance and thus to an excessively high warming of the bus conductors during operation. Further, it is difficult to manufacture a thinner bus conductor by a printing technique such as screen printing. Thicker bus conductors require an undesirably high material usage. Furthermore, the bus conductors lead to an excessively large and unsightly limitation of the see-through area of the glass plate. The length of the bus conductor depends on the extent of the heating conductor or the surface to be heated. In the case of a bus conductor typically configured in the form of a strip, the longer of its dimensions is referred to as the length, while the less-long of its dimensions is referred to as the width.

If the cladding is also used outside the communication window for heating, the other (third and fourth) bus conductors are typically preferably arranged on the electrically conductive transparent cladding along the side edges and in particular run approximately parallel to one another. The length of the bus conductors is typically substantially the same as the length of the side edges of the conductive transparent coating, but may also be slightly larger or smaller. Preferably, in the edge regions along two opposite side edges of the electrically conductive transparent coating, more than two bus conductors can also be arranged on the electrically conductive coating. For example, around two or more separate heating fields, it is also possible to arrange more than two bus conductors on the electrically conductive transparent coating.

In an advantageous embodiment, the bus conductor according to the invention is designed as a printed and calcined electrically conductive structure. The printed busbar preferably contains at least one metal, metal alloy, 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, for example silver particles. The electrical conductivity is preferably achieved by conductive particles. The particles can be in an organic and/or inorganic matrix, for example a paste or ink, preferably as a printing paste with glass frit.

The layer thickness of the printed busbar is preferably 5 μm to 40 μm, particularly preferably 8 μm to 20 μm and very particularly preferably 8 μm to 12 μm. Printed bus conductors with these thicknesses are technically simple to implement and have an advantageous current-carrying capacity.

Specific resistance ρ of the bus conductor_aPreferably 0.8 to 7.0 μ Ohm cm and particularly preferably 1.0 to 2.5 μ Ohm cm. A bus conductor with a specific resistance in this range is technically simple to implement and has an advantageous current-carrying capacity.

Alternatively, however, the bus conductors can also be configured as strips of a conductive film. The busbar conductor then comprises, for example, at least aluminum, copper, tin-plated copper, gold, silver, zinc, tungsten and/or tin or alloys thereof. The strips preferably have a thickness of 10 μm to 500 μm, particularly preferably 30 μm to 300 μm. Bus conductors made of conductive films having these thicknesses can be realized technically simply and have an advantageous current-carrying capacity. The strip may be conductively connected with the conductive structure, for example via solder, via a conductive adhesive or by direct mounting.

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

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

Essentially all electrically insulating substrates which are thermally and chemically stable and dimensionally stable under the conditions of manufacture and use of the glass sheets according to the invention are suitable as first glass sheet and, if appropriate, second glass sheet.

The first glass plate and/or the second glass plate preferably comprise glass, particularly preferably flat glass, float glass, quartz glass, borosilicate glass, soda-lime glass; or comprise a clear plastic, preferably a rigid clear plastic, in particular polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, polystyrene, polyamide, polyester, polyvinyl chloride and/or mixtures thereof. The first glass pane and/or the second glass pane are preferably transparent, in particular for the use of the glass pane as a windshield pane or rear side pane (rackscheibe) of a vehicle or for other applications in which a high light transmission is desired. Transparent in the sense of the present invention is then understood to be a glass plate having a transmission in the visible spectral range of more than 70%. But for glass panels which are not located in the driver's traffic-related field of view, for example for roof glass panels, the transmission can also be much lower, for example greater than 5%.

The thickness of the glass plate can vary widely and can therefore be excellently adapted to the requirements of the individual case. Glass sheets having a standard thickness of 1.0 mm to 25 mm, preferably 1.4 mm to 2.5 mm, are preferably used for vehicle glazing and glass sheets having a standard thickness of preferably 4 mm to 25 mm are used for furniture, equipment and buildings, in particular for electrical heaters. The size of the glass sheet can vary widely and depends on the size of the use according to the invention. For example, the first glass sheet and, if necessary, the second glass sheet have the common areas of 200 cm up to 20 m in the vehicle manufacturing and building fields.

The glass sheet may 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 substrate is preferably flat or slightly or strongly curved in one or more directions in space. In particular, a flat substrate is used. The glass plate may be colorless or colored.

The glass sheets are connected to one another by at least one intermediate layer. The intermediate layer preferably comprises at least one thermoplastic, preferably polyvinyl butyral (PVB), Ethylene Vinyl Acetate (EVA) and/or polyethylene terephthalate (PET). However, the thermoplastic intermediate layer may also for example comprise Polyurethane (PU), polypropylene (PP), polyacrylate, Polyethylene (PE), Polycarbonate (PC), polymethyl methacrylate, polyvinyl chloride, polyacetate resins, casting resins, acrylates, fluorinated ethylene propylene, polyvinyl fluoride and/or ethylene tetrafluoroethylene or copolymers or mixtures thereof. The thermoplastic intermediate layer can be formed by a thermoplastic film or by a plurality of thermoplastic films arranged one above the other, the thickness of the thermoplastic film preferably being 0.25 mm to 1mm, typically 0.38 mm or 0.76 mm.

In the case of the composite glass pane according to the invention, which consists of the first glass pane, the intermediate layer and the second glass pane, the electrically conductive transparent coating can be applied directly to the first glass pane or can be applied to the carrier film or to the intermediate layer itself. The first and second glass plates have inner and outer side surfaces, respectively. The inner side surfaces of the first and second glass sheets face each other and are connected to each other via a thermoplastic interlayer. The outside surfaces of the first and second glass sheets face away from each other and from the thermoplastic interlayer. A conductive coating is applied to the inside surface of the first glass sheet. Of course, other conductive coatings may be applied to the inside surface of the second glass sheet. The outer side surfaces of the glass sheets may also have a coating. The terms "first glass sheet" and "second glass sheet" are chosen to distinguish the two glass sheets in the case of a composite glass sheet according to the invention. Statements about the geometric arrangement are not associated with these terms. If the glass pane according to the invention is provided, for example, for separating an interior space from an exterior environment in an opening of, for example, a vehicle or a building, the first glass pane can be directed towards the interior space or towards the exterior environment.

The electrically conductive transparent coating according to the invention is known, for example, from DE 202008017611U 1, EP 0847965B 1 or WO2012/052315 a 1. The transparent conductive coating typically comprises one or more, for example two, three or four, conductive functional layers. The functional layer preferably comprises at least one metal, for example silver, gold, copper, nickel and/or chromium or a metal alloy. The functional layer particularly preferably comprises at least 90 wt.% (Gew.%) metal, in particular at least 99.9 wt.% metal. The functional layer may be composed of a metal or a metal alloy. The functional layer particularly preferably comprises silver or a silver-containing alloy. Such functional layers have a particularly advantageous electrical conductivity at the same time in the high transmission in the visible spectral range. The thickness of the functional layer is preferably from 5 nm to 50 nm, particularly preferably from 8 nm to 25 nm. In this range of 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, respectively. Further dielectric layers are preferably arranged below the first functional layer and/or above the last functional layer. The dielectric layer comprises at least one single layer made of a dielectric material, for example comprising a nitride such as silicon nitride or an oxide such as aluminum oxide. However, the dielectric layer may also comprise a plurality of monolayers, such as a monolayer of a dielectric material, a smoothing layer, an adaptation layer, a barrier layer (Blockerschichten), and/or an antireflective layer. The thickness of the dielectric layer is, for example, 10 nm to 200 nm.

This layer structure is usually obtained by a series of deposition processes, which are carried out by vacuum methods, such as magnetic field assisted cathode sputtering.

Other suitable conductive coatings preferably comprise Indium Tin Oxide (ITO), fluorine-doped tin oxide (SnO)₂F) or aluminum-doped zinc oxide (ZnO: Al).

The electrically conductive transparent coating can in principle be any coating which should be electrically contacted and which has sufficient transparency. If the glass pane according to the invention should be transparent, as is the case, for example, with glass panes in the window area, the electrically conductive coating is preferably transparent. The electrically conductive coating according to the invention is preferably transparent to electromagnetic radiation, particularly preferably to electromagnetic radiation of a wavelength of 300 to 1300 nm and in particular to visible light.

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

The electrically conductive coating according to the invention advantageously has a surface resistance of 0.4 to 10 ohms/square. In a particularly preferred embodiment, the electrically conductive coating according to the invention has a surface resistance of 0.5 to 1 ohm/square. Coatings with such surface resistances are particularly suitable for heating vehicle glass panes at typical vehicle voltages of 12V to 48V or in the case of electric vehicles with typical vehicle voltages up to 500V.

The conductive transparent coating may extend over the entire surface of the first glass plate. Alternatively, however, the electrically conductive transparent coating may also extend over only a part of the surface of the first glass plate. The electrically conductive transparent coating preferably extends over at least 50%, particularly preferably at least 70% and very particularly preferably at least 90% of the inner side surface of the first glass pane. The conductive transparent coating may have one or more uncoated regions in addition to the uncoated region.

In an advantageous embodiment of the glass pane according to the invention as a composite glass pane, the inner surface of the first glass pane has a circumferential edge region with a width of 2 mm to 50 mm, preferably 5 mm to 20 mm, which is not provided with an electrically conductive transparent coating. The electrically conductive transparent coating then has no contact with the atmosphere and is advantageously protected from damage and corrosion in the interior of the glass pane by the thermoplastic intermediate layer.

The bus conductors are electrically contacted by one or more leads. The lead is preferably designed as a flexible foil conductor (flat conductor, flat ribbon conductor). This is understood to be an electrical conductor whose width is significantly greater than its thickness. Such thin-film conductors are, for example, strips or ribbons comprising or consisting of copper, tin-plated copper, aluminum, silver, gold or alloys thereof. The thin-film 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, coating, for example based on polyimide. Thin-film conductors suitable for contacting the electrically conductive coating in the glass pane have a total thickness of, for example, only 0.3 mm. Such thin film conductors can be embedded without difficulty in the thermoplastic intermediate layer between the individual glass panes. A plurality of conductive layers electrically insulated from each other may be located in the thin film conductor strip.

Alternatively, thin wires may also be used as electrical leads. The metal wire is in particular copper, tungsten, gold, silver or aluminum or an alloy of at least two of these metals. The alloy may also comprise molybdenum, rhenium, osmium, iridium, palladium, or platinum.

In an advantageous embodiment of the invention, the electrical leads are connected to the contact strips, for example by means of solder or an electrically conductive adhesive. The contact strip is then connected to the busbar. In the sense of the present invention, a contact strip is an extension of a lead, so that a connection surface between the contact strip and a busbar can be understood as a contact surface according to the present invention, from which the distance a extends in the direction of extension of the busbar. The contact strip preferably comprises at least one metal, particularly preferably copper, tin-plated copper, silver, gold, aluminum, zinc, tungsten and/or tin. This is particularly advantageous in terms of the conductivity of the contact strip. The contact strip may also comprise an alloy, which preferably comprises one or more of the elements mentioned and, if appropriate, 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 having these thicknesses are technically simple to produce and readily usable and, furthermore, have a advantageously low electrical resistance.

The invention furthermore comprises a method for manufacturing a glass sheet according to the invention, the method comprising at least:

(a) applying an electrically conductive transparent coating to the surface of a glass pane having at least two coating-free regions and a heating conductor arranged therebetween, which consists of a region of the coating, and

(b) at least two bus conductors, which are provided for connection to a voltage source, are applied, the bus conductors being connected to the heating conductors, so that a current path for the heating current is formed between the bus conductors.

The application of the electrically conductive coating of the electrically conductive transparent coating in process step (a) can be carried out by methods known per se, preferably by magnetic field-assisted cathode sputtering. This is particularly advantageous in terms of a simple, fast, cost-effective and uniform coating of the first glass plate. However, the conductive coating can also be applied, for example, by evaporation, Chemical Vapor Deposition (CVD), plasma-assisted vapor deposition (PECVD) or by wet-chemical methods.

The first glass plate can be subjected to a heat treatment during process step (a) or after process step (a). The first glass plate with the electrically conductive coating is heated to a temperature of at least 200 ℃, preferably at least 300 ℃. The heat treatment may be used to increase transmission and/or reduce the surface resistance of the conductive coating.

The first glass sheet can be bent after method step (a), typically at a temperature of 500 ℃ to 700 ℃. This action is advantageous if the first glass plate should be bent, since coating a flat glass plate is technically simpler. Alternatively, however, it is also possible to bend the first glass plate before or during method step (a), for example when the electrically conductive coating is not suitable for being subjected to a bending process without damage.

The busbar is preferably applied in method step (b) by printing and firing a conductive paste in a screen printing method or in an inkjet method. Alternatively, the bus conductors may be applied, preferably mounted, welded or glued, as strips of conductive film onto the conductive coating.

In the case of the screen printing method, the transverse shaping is carried out by a masking fabric, through which the printing paste with the metal particles is pressed. For example, the width of the bus conductors can be predetermined and varied in a particularly simple manner by suitable shaping of the screen.

The respective coating-free region in the (de) coating of the electrically conductive coating is preferably produced by means of a laser beam. Methods for structuring thin metal films are known, for example, from EP 2200097 a1 or EP 2139049 a 1. The width of the stripping layer is preferably from 10 μm to 1000 μm, particularly preferably from 30 μm to 200 μm and in particular from 70 μm to 140 μm. In this region, a particularly clean and residue-free removal of the coating is carried out by the laser beam. The coating by means of a laser beam is particularly advantageous, since the coated lines are optically very inconspicuous and only have a very low influence on the appearance and the perspective. Lines having a width wider than that of the laser kerf (Laserschnitt) are decoated by abrading the lines with a laser beam multiple times. Process duration and process cost therefore increase as line widths increase. Alternatively, the de-coating may be performed by mechanical ablation 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) disposing a thermoplastic interlayer on the coated surface of the first glass sheet and a second glass sheet on the thermoplastic interlayer, and

(d) the first glass sheet and the second glass sheet are connected via a thermoplastic interlayer.

In method step (c), the first glass plate is arranged such that the one of its surfaces which is provided with the electrically conductive transparent coating faces the thermoplastic intermediate layer. This surface thus becomes the inner surface of the first glass plate.

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

The first and second glass plates are preferably joined in method step (d) under the action of heat, vacuum and/or pressure. Methods known per se for manufacturing glass sheets can be used.

For example, the so-called autoclave process may be performed at an elevated pressure of about 10 to 15 bar and a temperature of 130 to 145 ℃ over about 2 hours. The vacuum bag or vacuum ring method known per se works, for example, at approximately 200 mbar and 80 ℃ to 110 ℃. The first glass sheet, the thermoplastic interlayer and the second glass sheet may also be pressed into a glass sheet in a calender between at least one pair of rolls. For the manufacture of glass sheets, apparatuses of this type are known and usually have at least one heating tunnel before the press. The temperature during the pressing process is, for example, 40 ℃ to 150 ℃. The combination of the calender process and the autoclave process has proven to be particularly effective in practice. Alternatively, a vacuum laminator may be used. The vacuum laminator consists of one or more heatable and evacuable chambers, wherein the first glass plate and the second glass plate are laminated at a reduced pressure of 0.01mbar to 800 mbar and a temperature of 80 ℃ to 170 ℃ within e.g. about 60 minutes.

The invention furthermore comprises the use of the glass pane according to the invention with electrical contact in buildings, in particular in the area of entrance, window, roof or house facade, as a built-in part in furniture and installations, in means of transport for land, air or water traffic, in particular in trains, ships and motor vehicles, for example as a windshield pane, rear window pane, side window pane and/or roof window pane. Applications include optical sensors and camera systems, in particular for vision-based driver assistance systems FAS or advanced driver assistance systems ADAS, the light path of which extends through the communication window.

Drawings

The invention is explained in more detail below with reference to the figures and examples. The figures are schematic and not drawn to scale. The drawings do not limit the invention in any way.

Figure 1A shows a top view of one configuration of a glass sheet having an electrically heatable communication window according to the present invention,

figure 1B shows an enlarged view of the communication window of figure 1A,

figure 1C shows a cross-sectional view through the glass sheet according to figure 1A along cutting line a-a',

FIG. 2 shows a top view of another configuration of a glass sheet according to the invention, an

Fig. 3 shows a flow chart of an embodiment of the method according to the invention.

Detailed Description

Fig. 1A shows a top view of one exemplary configuration of a glass sheet 100 having an electrically heatable communication window 80 in accordance with the present invention. FIG. 1B shows an enlarged view of the communication window of FIG. 1A and FIG. 1C shows a cross-section through the glass sheet 100 of FIG. 1A according to the present invention along cut line A-A'.

The glass pane 100 comprises a first glass pane 1 and a second glass pane 2 which are connected to one another via a thermoplastic interlayer 4. The glass pane 100 is, for example, a vehicle glass pane and in particular a windscreen of a passenger car. For example, the first glass pane 1 is arranged for being directed towards the interior space in the mounted position. The first glass plate 1 and the second glass plate 2 are made of soda lime glass. The thickness of the first glass plate 1 is, for example, 1.6 mm and the thickness of the second glass plate 2 is 2.1 mm. The thermoplastic interlayer 4 is made of polyvinyl butyral (PVB) and has a thickness of 0.76 mm. A conductive transparent coating 3 is applied on the inner side surface III of the first glass plate 1. The electrically conductive transparent coating 3 is a layer system comprising, for example, three electrically conductive silver layers, which are separated from one another by dielectric layers. If an electric current flows through the conductive transparent cover layer 3, it is warmed up due to its resistance and joule heat release. Thus, the conductive transparent overlay 3 may be used to actively heat the communication window 80.

The conductive transparent coating 3, 3' extends, for example, over the entire surface III of the first glass plate 1 minus the surrounding frame-shaped uncoated area with a width of 8 mm. The uncoated regions serve for electrical insulation between the electrically conductive transparent coating 3' and the vehicle body. The uncoated areas are hermetically sealed by bonding with the intermediate layer 4 in order to protect the conductive transparent cover layer 3, 3' from damage and corrosion.

The electrically conductive transparent cladding 3, 3 'is not used in this embodiment to heat the entire glass sheet 100 completely, but instead uses the IR-reflective properties of the cladding 3, 3', for example in order to protect the interior of the vehicle from solar radiation and to keep it cool. (see FIG. 2 for an example of a fully heatable glass sheet 100.)

The communication window 80 is surrounded here, for example, by an uncoated separation line 9, which separates the coating 3 in the interior of the communication window 80 from the surrounding coating 3' material and is galvanically isolated (i.e. for direct current). The separation line 9 has, for example, a width d of 100 μm, wherein the coating 3 is completely removed. The separation lines 9 are produced, for example, by laser structuring (laser ablation).

In this example, the conductive transparent cladding 3 within the communication window 80 has six cladding-free regions 8. A coated region in the form of a heating conductor 12 is arranged between the uncoated regions 8. The width b of the heating conductor 12 is constant here, for example, along the heating conductor 12 and is constant in all intermediate regions. The width b here is preferably 0.1 mm to 1.5 mm, particularly preferably 0.1 mm to 0.6 mm, in particular 0.20 mm to 0.45 mm and is, for example, 0.25 mm or 0.4 mm.

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

In this example, the uncoated region 8 has a width B of 1 cm and a length L of 7 cm. Only the uppermost uncoated region 8.3 extends in sections to the right of the separating line 9, in order to isolate the coating 3 in the environment of the bus bar conductor 5.1 from the coating 3 in the environment of the bus bar conductor 5.2 and to prevent short circuits between the bus bar conductors 5.1, 5.2. Likewise, the lower uncoated zone 8.4 is widened and guided on its underside as far as the parting line 9. This also serves for current isolation and for avoiding undesired short-circuits between the busbar conductors 5.1, 5.2.

The communication window 80 is adapted to ensure perspective to the camera system 20 or other optical sensor. For this purpose, the imaging window 10, i.e. the region of the beam path of the imaging system 20 through the glass pane 100, is arranged completely within the electrically heatable region formed by the uncoated region 8 and the heating conductor 12. This arrangement of the uncoated region 8 and the narrow transparent heating conductor 12 is optically hardly perceptible for the camera system 20 and only minimally disturbs the transmission through the glass pane 100, which is particularly important for use in camera systems 20 and vehicles with high optical requirements.

For the electrical contacting, the first bus conductor 5.1 is arranged on the electrically conductive transparent coating 3 in each case at the left edge region of the uncoated region 8 or the heating conductor 12 and the other second bus conductor 5.2 is arranged on the right edge region. The bus conductors 5.1, 5.2 contain, for example, silver particles and are applied in a screen printing method and subsequently calcined. The length of the busbar conductors 5.1, 5.2 corresponds approximately to the extent of the cladding-free region 8 together with the heating conductor 12 (ausdehnnung).

If a voltage is applied to the bus conductors 5.1 and 5.2, a uniform current flows through the heating conductor 12 between the bus conductors 5.1, 5.2, as a result of which the communication window 80 and in particular the sensor or camera window 10 is heated.

Each bus conductor 5.1, 5.2 can be led to a connection region, which is equipped with a terminal or connection conductor 7.1, 7.2, respectively, which connects the bus conductor 5.1, 5.2 with the voltage source 14. The connecting lines 7.1, 7.2 can be formed as film conductors known per se, which are connected to the busbar conductors 5.1, 5.2 in an electrically conductive manner via contact surfaces, for example by means of solder, conductive adhesive or by simple laying and pressing within the glass pane 100. The thin-film conductor comprises, for example, a tin-plated copper thin film having a width of 10 mm and a thickness of 0.3 mm. Via the film conductor, it can be transferred into a connecting cable, which is connected to the voltage source 14. The voltage source 14 supplies, for example, a vehicle voltage which is customary for motor vehicles, preferably 12V to 15V and, for example, approximately 14V. Alternatively, the voltage source 14V may also have a higher voltage of, for example, 35V to 45V and in particular 42V.

In the example shown, the busbar 5.1, 5.2 has a constant thickness of, for example, approximately 10 μm and a constant specific resistance of, for example, 2.3 μ Ohm cm.

When a voltage is applied to the busbar 5.1, 5.2, a current flows through the heating conductor 12. The current path 11 between the uncoated regions 8.1, 8.2 is drawn here by way of example. It goes without saying that corresponding current paths 11 are also present in the other heating conductors 12.

As is usual in the vitrification technology, the bus conductors 5.1, 5.2 and the terminals and the connecting lines 7.1, 7.2 can be screened off by means of an opaque color layer known per se as a masking print (not shown here).

Fig. 2 shows a top view of another configuration of a glass sheet 100 according to the invention. The first glass plate 1, the second glass plate 2, the conductive transparent cover 3 and the communication window 80 and the thermoplastic interlayer 4 are configured as shown in fig. 1A.

Additionally, the glass pane 100 according to fig. 2 is also electrically heatable in the cladding region 3', i.e. also outside the communication window 80. In order to electrically contact the coating 3 'outside the communication window 80, the first bus conductor 50.1 is arranged in the lower edge region and the further second bus conductors 50.2 are arranged in the upper edge region on the electrically conductive transparent coating 3', respectively. The bus conductors 50.1, 50.2 contain silver particles, for example, and are applied in a screen printing method and subsequently calcined. The length of the bus conductors 50.1, 50.2 corresponds approximately to the extent of the conductive transparent coating 3'.

If a voltage is applied to the bus conductors 50.1 and 50.2, a uniform current flows (for example along the current path 110) through the conductive transparent coating 3' between the bus conductors 50.1, 50.2. A terminal with a lead 70.1, 70.2 is arranged approximately centrally on each busbar 50.1, 50.2. The terminals 70.1, 70.2 are, for example, film conductors known per se, which are turned into round cables. The terminals 70.1, 70.2 are connected in an electrically conductive manner to the bus conductors 50.1, 50.2 via contact surfaces, for example by means of solder, electrically conductive adhesive or by simple laying and pressing within the glass pane 100. The thin-film conductor comprises, for example, a tin-plated copper thin film having a width of 10 mm and a thickness of 0.3 mm. Via the electrical connections 70.1, 70.2, the bus conductors 50.1, 50.2 are connected, for example, to a voltage source 14, which (as already stated) supplies an onboard voltage, which is preferably 12V to 15V and is, for example, approximately 14V, as is customary for motor vehicles. Alternatively, the voltage source 14V may also have a higher voltage of, for example, 35V to 45V and in particular 42V. Alternatively, other voltage sources having the same or different voltages as the voltage source 14 may be connected to the terminals 70.1, 70.2.

In table 1, the simulation results for the glass plate 100 according to the invention for different widths b of the heating conductor 12 are summarized.

Table 1

。

The glass pane 100 according to the invention simulated here according to fig. 1A, 1B and 1C with a width of the heating conductor 12 of 0.25 mm or 0.4 mm all shows a complete de-icing of the glass pane 100 within the required 10 min in the region of the camera window 10.

Fig. 3 shows a flow chart of an embodiment of the method according to the invention for producing an electrically heatable glass 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 glass pane 1 having at least two coating-free regions 8 and a heating conductor 12 arranged therebetween, which consists of a region of the coating 3, and

s2: at least two bus conductors 5.1, 5.2 are applied, which are provided for connection to a voltage source 14 and are connected to the heating conductor 12, so that a current path 11 for the heating current is formed between the bus conductors 5.1, 5.2.

List of reference numerals:

1 first glass plate

2 second glass plate

3. 3' (conductive, transparent) coating

4 thermoplastic interlayer

5.1, 5.2, 50.1, 50.2 bus conductors

7.1, 7.2, 70.1, 70.2 terminal

8. 8.1, 8.2, 8.3, 8.4 uncoated areas

9 parting line

10 Camera Window

11. 110 current path

12 heating conductor

14 Voltage Source

20 image pickup system

80 (electrically heatable) communication window

100 glass plate

II surface of the second glass plate 2

III surface of the first glass plate 1

b width of heating conductor 12

d width of the separation line 9

Width of the B cladding-free zone 8

L length of the cladding-free zone 8

Method steps S1, S2

ρ_aSpecific resistance of the bus conductors 5, 50

A-A' cutting line.

Claims

1. A glass pane (100) having an electrically heatable communication window (80), the glass pane comprising at least:

-a first glass plate (1) having a surface (III),

-at least one electrically conductive transparent coating (3) applied at least on a portion of the surface (III) and having at least two coating-free regions (8, 8.1, 8.2), wherein

Between the regions (8, 8.1, 8.2) without coating, a heating conductor (12) consisting of a coating (3) is present, and

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

2. Glass 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 regions (8, 8.1, 8.2) between which in each case a heating conductor (12) is arranged.

3. Glass pane (100) according to claim 2, wherein the heating conductors (12) are configured in an electrically parallel manner with respect to each other.

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

5. Glass pane (100) according to any one of claims 1 to 4, wherein the width b of the heating conductor (12) is 0.1 to 1.5 mm, preferably 0.1 to 0.6 mm and particularly preferably 0.20 to 0.45 mm.

6. Glass sheet (100) according to any one of claims 1 to 5, wherein the non-cladding region (8) is rectangular and preferably has 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.

7. The glazing (100) according to any of claims 1 to 6, wherein the communication window (80) is completely galvanically separated and/or materially separated from the surrounding cladding (3') by a non-clad separation line (9), and the width d of the separation line (9) is preferably 30 to 200 μm and particularly preferably 70 to 140 μm.

8. Glass pane (100) according to one of claims 1 to 7, wherein at least two bus conductors (50.1, 50.2) provided for connection to the voltage source (14) or to a further voltage source are connected with the cladding (3 ') surrounding the communication window (80) such that a current path (110) for the heating current is formed between the bus conductors (50.1, 50.2), and wherein the current along the current path (11) between the bus conductors (5.1, 5.2) connecting the heating conductors (12) to each other and the current along the current path (110) between the bus conductors (50.1, 50.2) connecting the cladding (3') surrounding the communication window (80) can preferably be controlled independently of each other.

9. Glass pane (100) according to one of claims 1 to 8, wherein the busbar (5.1, 5.2, 50.1, 50.2) is configured as a fired printing paste,the printing paste preferably contains particles of metal, metal particles and/or carbon particles and in particular silver particles and preferably has a specific resistance ρ of 0.8 μ ohm-cm to 7.0 μ ohm-cm and particularly preferably 1.0 μ ohm-cm to 2.5 μ ohm-cm_a。

10. Glass pane (100) according to any one of claims 1 to 9, wherein the surface (III) of the first glass pane (1) is connected in a planar manner to the second glass pane (2) via a thermoplastic interlayer (4).

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

12. Glass pane (100) according to any one of claims 1 to 11, wherein the transparent conductive coating (3) has a surface resistance of 0.4 to 10 ohm/square and preferably of 0.5 to 1 ohm/square and/or comprises silver (Ag), Indium Tin Oxide (ITO), fluorine-doped tin oxide (SnO)₂F) or aluminum-doped zinc oxide (ZnO: Al).

13. A method for manufacturing a glass sheet (100) according to any of claims 1 to 12, the method comprising at least:

(a) applying an electrically conductive transparent coating (3) to a surface (III) of a glass pane (1) having at least two coating-free regions (8) and a heating conductor (12) arranged therebetween, which consists of a region of the coating (3), and

(b) at least two bus conductors (5.1, 5.2) which are provided for connection to a voltage source (14) are applied and connected to the heating conductor (12) in such a way that a current path (11) for a heating current is formed between the bus conductors (5.1, 5.2).

14. The method according to claim 13, wherein the cladding-free region (9) and/or the separation line (9) is produced by laser structuring and in particular by laser ablation of the cladding (3).

15. Use of a glass pane (100) according to any one of claims 1 to 12 as a functional single piece, as a built-in part of furniture, equipment and buildings, or as a glass pane in a means of transport for road, air or water traffic, preferably as a windscreen pane, rear window pane, side window pane or roof window pane of a motor vehicle, with an optical sensor and a camera system (20), in particular for a vision-based driver assistance system FAS or an advanced driver assistance system ADAS, the light path of which extends through the communication window.