Heated vehicle window

Abstract

A vehicle window pane provided with a first group of parallel conductor tracks (1) with spacings between adjacent conductor tracks (1) of less than 15 mm and with a second group of parallel conductor tracks (2) with spacings between adjacent conductor tracks (2) of less than 1 mm, wherein the conductor tracks (1) of the first group are arranged at a finite angle to the conductor tracks (2) of the second group, so that at intersection points (3) a conductor track (1) of the first group overlaps with a conductor track (2) of the second group, wherein in a heating region (H) of the vehicle window, the conductor tracks (1) of the first group are electrically conductively connected to the conductor tracks (2) of the second group at the intersection points (3) in such a way that the conductor tracks (1, 2) are suitable for heating the heating region (H) by an electric current conducted through the conductor tracks (1, 2).

Description

The invention relates to a vehicle window which can be heated at least locally.Heatable vehicle windows are known per se. For example, it is customary to provide rear panes of motor vehicles with printed-on heating conductors through which an electric current is conducted, if necessary, in order to heat the pane. These printed heating conductors are, however, very visually conspicuous, which restricts their possible uses.Furthermore, heatable windshields are known which place higher demands on transparency. The heating of windshields takes place either via a transparent coating, which generally contains silver, or via thin heating wires embedded in the windshield.There is still a need for vehicle windows with heating elements which can be integrated visually in an imperceptible and cost-effective manner.The object of the present invention is to provide such an improved heatable vehicle window.The invention is achieved by a vehicle window according to claim 1.The vehicle window according to the invention is provided with a first group of parallel conductor tracks and with a second group of parallel conductor tracks. The distances between adjacent conductor tracks within the first group or within the second group are less than 15 mm, preferably less than 1 mm. The conductor tracks of the first group are arranged at a finite angle to the conductor tracks of the second group, so that at so-called crossing points in each case one conductor track of the first group overlaps with a conductor track of the second group. Said angle is an angle not equal to 0° and 180°, in particular between 0° and 180°, preferably from 45° to 135°, particularly preferably 90°.The vehicle window has a heating region. The heating region is formed by at least a part of the crossing points. In this heating region, the conductor tracks of the first group are electrically conductively connected to the conductor tracks of the second group at the crossing points in such a way that the conductor tracks are suitable for heating the heating region by an electrical current conducted through the conductor tracks. The conductor tracks are accordingly electrically contacted for this purpose.The thin conductor tracks are hardly visible and only insignificantly restrict the view through the vehicle window. Conductor tracks of this type are common, in particular for the electrical supply of micro-LEDs. They can therefore be integrated into the vehicle window at low cost, for example in the form of a purchased film-like component. These are great advantages of the present invention.In principle, it is also conceivable for the two groups of parallel conductor tracks to be arranged at an angle of 0°, that is to say to be oriented parallel to one another. The electrical connection between conductor tracks of the first and second group in the heating region can then take place at any desired locations which then correspond to the crossing points in the sense of the invention.In an advantageous embodiment, the vehicle window is a side window, rear window or roof window of a motor vehicle. A side window is particularly preferred, while heating functions are already established on the market for rear windows and roof windows are rarely heated, there is a particular need for solutions for integrating a heating function for side windows. The vehicle window can in principle also be a windshield, wherein due to legal requirements with regard to transparency it may be necessary not to provide a central main see-through region with the conductor tracks. However, such legal requirements could become irrelevant, particularly with regard to autonomous driving.In an advantageous embodiment, the electrical connection between the conductor tracks of the first group and the conductor tracks of the second group is effected at the crossing points by direct contact, via an electrical conductor, via an electrical resistor or via an electrical load.In one embodiment of the invention, the entirety of the grid-like arranged conductor tracks forms the heating region. In an advantageous embodiment, on the other hand, the vehicle window has an illumination region in addition to the heating region. In the illumination area, the conductor tracks of the first group are connected to the conductor tracks of the second group at the crossing points via micro-LEDs, so that illumination can be realized in the illumination area. The invention is then particularly advantageous because the conductor tracks must be present in any case for feeding the micro-LEDs, which are then also used for local heating. The heating function can then be implemented particularly cost-effectively, because no additional heating element has to be integrated into the pane.In a further embodiment, the vehicle window has a non-functional region in addition to the heating region and optionally the illumination region. The non-functional region is not used either for heating or for illumination. The non-functional region is particularly transparent due to the absence of micro LEDs and heating resistors. In the inoperative region, the conductor tracks of the first group are not electrically conductively connected to the conductor tracks of the second group at the crossing points.It is also conceivable that only one of the two groups of parallel conductor tracks is present in the inoperative region and the other group is missing. Material can thus be saved.The vehicle window can be formed, for example, from a single, in particular thermally prestressed, glass pane. The thickness of the glass pane is, for example, from 3 mm to 5 mm.The vehicle pane can alternatively be designed as a composite pane, comprising two glass panes that are connected to one another via a thermoplastic intermediate layer. The thickness of the glass panes is, for example, from 0.5 mm to 3 mm, in particular from 1 mm to 2.5 mm.The glass pane(s) is / are preferably formed from soda-lime glass. The intermediate layer in the case of a composite pane is preferably formed on the basis of polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) or polyurethane (PU).The invention is explained in more detail below with reference to a drawing and exemplary embodiments. The drawing is a schematic representation and not to scale. The drawing does not limit the invention in any way.The following are shown: FIG. 1 shows a top view of a first embodiment of the vehicle window according to the invention, FIG. 2 shows a top view of a second embodiment of the vehicle window according to the invention, FIG. 3 shows a top view of a third embodiment of the vehicle window according to the invention.FIG. 1 shows a top view of a first embodiment of the vehicle window according to the invention. The vehicle window is provided as a raisable and lowerable side window for a passenger car which is provided to be fitted into one of the front doors of the passenger car (driver's or passenger's door). However, the invention can also be applied to other vehicle panes, for example rear windows or roof panes.The vehicle window has a see-through region D, which in the closed state closes the window opening and allows a see-through through the window. It also has a connection region A, which is always arranged inside the door body and serves for connecting the vehicle window to the mechanism for raising and lowering the same. For this purpose, in the connection region A, feedthroughs 11 are formed through the vehicle window, in which a component can be clamped or screwed tight for this purpose. Alternatively, fastening elements can be fastened, for example glued, to the lower edge of the vehicle window, which in turn serve for the connection to the mechanism for raising and lowering and for this purpose are provided, for example, with feedthroughs.The vehicle window is provided, at least in the feedthrough region D, with a first group of conductor tracks 1, which are arranged horizontally and parallel to one another, and with a second group of conductor tracks 2, which are arranged vertically and parallel to one another. The angle between the conductor tracks 1 of the first group and the conductor tracks 2 of the second group is 90°. Each conductor track 1 of the first group overlaps with several conductor tracks 2, in particular all conductor tracks 2, of the second group at different locations, which are referred to as crossing points 3 in the sense of the invention. Likewise, each conductor track 2 of the second group overlaps with a plurality of conductor tracks 1, in particular all conductor tracks 1, of the first group at different crossing points 3.In plan view, the conductor tracks 1, 2 form a type of grid of horizontal and vertical conductor tracks which cross at crossing points 3. The conductor tracks 1, 2 are electrically conductive and are formed from copper, for example. The distance between adjacent conductor tracks 1 of the first group is, for example, approximately 200 μm, as is the distance between adjacent conductor tracks 2 of the second group. In other words, the conductor tracks 1, 2 form a uniform rectangular grid with a grid constant of 200 μm in plan view.The conductor tracks 1 of the first group and the conductor tracks 2 of the second group are basically not in electrically conductive contact with one another at the crossing points. This can be realized in that the first group of conductor tracks 1 and the second group of conductor tracks 2 are arranged in different planes of the vehicle window and are separated from one another by a (for example polymeric) layer, or in that the conductor tracks 1, 2 are indeed directly on one another at the crossing points, but are each provided with an insulating sheathing.Such conductor tracks 1, 2 are known per se to the person skilled in the art. They are typically used to supply electric power to micro LEDs which are arranged at the crossing points 3 respectively between the conductor track 1 of the first group and the conductor track 2 of the second group and connect these to one another, so that an electric voltage can be applied to each micro LED via a horizontal conductor track 1 and a vertical conductor track 2. By means of a first electrical potential which is applied to the corresponding horizontal conductor track 1 and a second electrical potential which is applied to the corresponding vertical conductor track 2, each micro-LED can be controlled in a targeted manner and can be supplied with a voltage in order to activate it.The core of the present invention is to use the conductor tracks 1, 2 for (in particular local) heating of the vehicle window. In a heating region H, the horizontal conductor tracks 1 are electrically conductively connected to the vertical conductor tracks 2 at the crossing points 3. By applying an electric voltage, a heating current can be conducted through the horizontal wiring 1, the crossover point 3 and the vertical wiring 2. The totality of the crossing points 3 at which the said connection between the conductor tracks 1, 2 is present forms the heating region H. The heating zone H is thus characterized by the totality of the crossing points 3 which are located therein. The heating power can be suitably adjusted by the voltage, so that the heating region H of the vehicle window can be freed from icing or condensed moisture if required. Voltage and current flow typically differ significantly from the use of the grid for the electrical supply of micro-LEDs and are adapted accordingly.The electrical connection at the crossing points 3 can be realized in different ways. If the conductor tracks 1, 2 are provided with an insulating sheathing and are located on top of one another at the crossing points, they can be short-circuited by local removal of the sheathing (electrical connection by direct electrical contact). The heating effect is then caused by the heat development as a result of the effect of the conductor tracks 1, 2 as an electrical resistance (so-called "Joule effect" according to the first Joule law / current heating law). Alternatively, electrical conductors can be provided at the crossing points 3, which run between the two conductor tracks 1, 2 and connect these to one another. The two conductor tracks 1, 2 are preferably connected to one another at the crossing points 3 via an electrical load (for example a diode) or an electrical resistor, as a result of which the heating effect can be increased.In the embodiment shown, the see-through area D is divided into a heating area H which extends around the frame-like periphery and is arranged at the edge of the see-through area D and surrounds an illumination area L. In the heating region H, the grid of conductor tracks 5 is used for heating as described. The edge region of the see-through region is typically in contact with sealing lips in the closed state of the side window. Frosting can lead to the side window no longer being able to be lowered at low external temperatures and consequently the side window no longer being able to be opened. The edge region can be quickly defrosted by the heating region H, so that the side window can be opened again.In the illumination region L, the conductor tracks 1 of the first group are connected to the conductor tracks 2 of the second group at the crossing points 3 via micro-LEDs (one micro-LED at each crossing point). The conductor tracks 1, 2 are thus used in a conventional manner for operating the micro-LEDs. With the micro-LEDs, an illumination can be realized, for example for the purpose of displaying information outwards or for the purpose of producing an aesthetic illumination for the vehicle interior.FIG. 2 shows a top view of a second embodiment of the vehicle window according to the invention. It differs from the first embodiment in that the area surrounded by the heating area H is divided into the illumination area L and a non-functional area U. In the non-functional area U, the grid of conductor tracks 5 is neither used for heating nor are micro-LEDs present for illumination. Accordingly, the conductor tracks 1 of the first group are not electrically connected to the conductor tracks 2 of the second group at the crossing points 3. The region U has no function except for maintaining the integrity of the conductive tracks 5.FIG. 3 shows a top view of a third embodiment of the vehicle window according to the invention. Here, the heating region H is arranged in the front region of the side window, which is located between the driver and the side mirror. In the case of an icy pane, the rapid defrosting in this area is particularly necessary in order to enable the driver to look at the side mirror. The remaining see-through area D is a non-functional area U.The exemplary embodiments illustrated in FIGS. 1 to 3 can of course also be combined with one another. Thus, a side window can also be equipped both with a heating area H in a circumferential edge area as in FIGS. 1 and 2 and with a heating area H in a front area of the side mirror as in FIG. 3. The heating area H in a front portion of the side mirror as in FIG. 3 may also occur in conjunction with an illumination area L which is present instead of the entire inoperative area U or a part of the inoperative area U.In principle, the entire grid of conductor tracks 1, 2 can also be used for heating. Then, for example, the entire see-through area D would be configured as a heating area H.The end points of adjacent conductor tracks 1, 2, which are supplied with the same electrical potential, can be electrically contacted together via a busbar (busbar), in order to simplify the electrical connections. It is also possible to combine the end points of the horizontal conductor tracks 1 and the end points of the vertical conductor tracks 2 in the edge region of the vehicle window at one point in order to connect them there, for example by means of a plug, to the external voltage source.The conductor tracks 1, 2 are typically connected to the electrical loads (heating resistors and / or micro-LEDs) possibly located at the crossing points 3 as a separate foil-like component which is attached to the vehicle window or integrated into the vehicle window. Such a component typically contains at least one carrier film, for example made of a plastic or thin glass. All the conductor tracks 1, 2 can be arranged on a single carrier foil if they are provided with an insulating sheathing which prevents direct contact at the crossing points 3, or if an insulating lacquer layer is introduced between the first and the second group, for example. The component can contain two carrier foils, wherein the first group of conductor tracks 1 is arranged on one carrier foil and the second group of conductor tracks 2 on the other carrier foil. The two carrier foils can be connected to one another, for example, via an adhesive, in which any electrical consumers or connecting conductors are embedded at the crossing points 3.The film-like component can be attached, for example glued, to a glass pane which forms the vehicle pane or is a component thereof. If the vehicle pane is designed as a composite pane consisting of two glass panes joined via a thermoplastic intermediate layer, the component can also be incorporated into the intermediate layer, for example between two joining foils made of plasticized PVB.It is also conceivable for the conductor tracks to be applied directly to a glass pane. In the case of a composite pane, it is conceivable that the first group of conductor tracks 1 is applied to the first glass pane and the second group of conductor tracks 2 on the second glass pane, wherein any electrical consumers or connecting conductors run through the thermoplastic intermediate layer at the crossing points 3.The conductor tracks 5 can be printed on their substrate, for example, or can be formed from a full-surface coating by etching or laser ablation.Thermistors (NTC or PTC= can also be inserted between the conductor tracks 1, 2 at individual crossing points 3, by means of which thermistors the current temperature of the vehicle window can be determined at the corresponding point. This can be used, for example, to automatically activate the heating function when a certain temperature is undershot or to deactivate it when a certain temperature is exceeded.List of reference numbers:D see-through region A connection region 1 conductor track of the first group 2 conductor track of the second group 3 crossing point of the conductor tracks 1, 2 11 passage through the vehicle window H heating region of the vehicle window L illumination region of the vehicle window U inoperative region of the vehicle window

Claims

Vehicle window which is provided with a first group of parallel conductor tracks (1) with spacings of adjacent conductor tracks (1) of less than 15 mm and with a second group of parallel conductor tracks (2) with spacings of adjacent conductor tracks (2) of less than 1 mm, wherein the conductor tracks (1) of the first group are arranged at a finite angle to the conductor tracks (2) of the second group, so that at crossing points (3) in each case one conductor track (1) of the first group overlaps with a conductor track (2) of the second group, wherein in a heating region (H) of the vehicle window the conductor tracks (1) of the first group are electrically conductively connected at the crossing points (3) to the conductor tracks (2) of the second group in such a way that the conductor tracks (1, 2) are suitable for heating the heating region (H) by an electric current conducted through the conductor tracks (1, 2).Vehicle window according to claim 1, wherein said angle is from 45° to 135°, preferably 90°.Vehicle window according to Claim 1 or 2, which is a side window, rear window, windshield or roof window of a motor vehicle, preferably a side window.Vehicle window according to one of Claims 1 to 3, wherein, in the heating region (H), at the crossing points (3), the conductor tracks (1) of the first group are connected to the conductor tracks (2) of the second group by direct contact, via an electrical conductor, via an electrical resistor or via an electrical load.Vehicle window pane according to one of claims 1 to 4, which, in addition to the heating area (H), has an illumination area (L), in which the conductor tracks (1) of the first group are connected to the conductor tracks (2) of the second group at the crossing points (3) via micro-LEDs.Vehicle window according to one of Claims 1 to 5, which, in addition to the heating region (H) and optionally the illumination region (L), has a non-functional region (U), in which the conductor tracks (1) of the first group are not connected to the conductor tracks (2) of the second group at the crossing points (3).

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