DE102016205402A1 - vehicle window - Google Patents

Abstract

Disclosed is a vehicle window (SA), in particular for a motor vehicle, having a first transparent pane (TS1) and a second transparent pane (TS2). Furthermore, the vehicle window has an optical component (OB) for controlling a light transmittance comprising an optically active layer (OAS) whose light transmittance is reversibly changeable by applying a voltage, a first electrically conductive layer (ELS1) on a first side of the optically active Layer is disposed, and a second electrically conductive layer (ELS2), which is arranged on a second side of the optically active layer, wherein by the first and the second electrically conductive layer, a voltage to the optically active layer can be applied. Finally, the vehicle window has a heater (HE) for heating the optically active layer to ensure its proper operation even at low temperatures.

Description

The present invention relates to a vehicle window, in particular for a motor vehicle whose light transmittance is variable. Furthermore, the present invention relates to an optical component, in particular for a vehicle window, for controlling the light transmittance. Finally, a method for operating a transparent pane arrangement, in particular a vehicle window is disclosed.

Today's motor vehicles have a passenger compartment, the u. a. is limited by transparent slices. These windows are translucent, so that the driver or other passengers can observe the surroundings of the vehicle. In modern vehicles is sometimes also a transparent window in the vehicle roof, through which sunlight can enter from above into the passenger compartment, to give the vehicle occupants a more natural driving experience. In order to reduce or prevent the solar radiation via the transparent pane in the vehicle roof, mechanical screens are generally provided, which are displaceable for the partial or complete overlapping of the transparent pane in the vehicle roof.

However, it is also conceivable to use switchable glazings instead of mechanically displaceable devices for effecting glare protection (also known as smart glass = intelligent glass in English). In this case, the light transmittance of such a switchable glazing by applying a voltage to a corresponding functional layer in the glazing effect a change in the light transmission, and thus also a glare protection. A disadvantage of such switchable glazing is that it has a long switching time or reaction time at low temperatures, in particular below 0 ° C., or does not even function below certain temperatures.

Thus, the object of the present invention to provide a way to ensure the operation of an electrically switchable transparent pane, in particular for a motor vehicle.

This object is solved by the subject matters of the independent claims. Advantageous embodiments are the subject of the dependent claims.

According to a first aspect of the invention, a vehicle window is provided, in particular for a motor vehicle. This may in particular be a vehicle window for limiting a passenger compartment, including a window in the roof of the vehicle. This vehicle window has a first transparent pane and a second transparent pane. In addition, it has an optical component arranged between the first and the second transparent pane for controlling a light transmission of the vehicle window. This optical component comprises an optically active layer whose light transmittance is reversibly changeable by applying a voltage. Further, it has a first electrically conductive layer as the first electrode disposed on a first side of the optically active layer. In addition, it has a second electrically conductive layer as a second electrode which is arranged on a second side of the optically active layer, wherein a voltage can be applied to the optically active layer through the first and the second electrically conductive layer. Finally, the windowpane has a heater for heating the optically active layer. In this way it is possible for the optically active layer to be supplied with heat even at low ambient temperatures of the window pane in order to ensure reliable operation of the vehicle window, and in particular the optically active layer, ie. h., To ensure a desired change in the light transmittance of the optically active layers and thus the window pane.

According to one embodiment of the vehicle window or of the optical component, only the first or only the second electrically conductive layer or both layers each have a respective first electrical connection at a first layer boundary and a respective second electrical connection at a second layer boundary, for an electric current to conduct the first or the second electrically conductive layer or through both electrically conductive layers in the layer plane. In this way, the ohmic resistance of a respective electrically conductive layer is used, so that caused by this conditional heat loss when passing the electric current, so as to realize the heater and to heat the optically active layer. In this embodiment, at least one of the first or second electrically conductive layers thus receives a dual function, namely for providing an electrical voltage for changing the light transmittance of the optically active layer, and as a heating device for heating the optically active layer when an electric current in the Layer plane flows. In this way, only by the provision of a first and second electrical connection to an electrically conductive layer, a cost-effective and space-saving heating device can be realized by which neither the dimensions of the optical component or the vehicle window are increased.

According to one embodiment of the vehicle window just mentioned, a first low-resistance element which is connected to the first electrical connection and expands at least over a certain subregion of the layer boundary is provided on the first layer boundary of the first or the second or both electrically conductive layers. Accordingly, a second low-resistance element which is connected to the second electrical connection and expands at least over a certain subregion of the layer boundaries is provided on the respective second layer boundary of the first or the second or both electrically conductive layers. The first or second low-resistance element has a lower resistance than the respective electrically conductive layers. For example, a low-resistance element may be realized by a copper layer or a copper element which is in electrical contact with a layer boundary of a respective electrically conductive layer. Between a respective first and second low-resistance element can be generated in this way, a surface current within a corresponding electrically conductive layer, by the loss of heat, the optically active layer is heated. As already mentioned, a respective low-resistance element can extend over a specific subregion of a layer boundary or along the entire layer boundary.

According to a further refinement of the vehicle window or of the optical component, the first electrically conductive layer or the second electrically conductive layer or both layers has a further electrically conductive layer or further electrode on a side remote from the optically active layer. In this further electrically conductive layer, a further first electrical connection is provided on a further first layer boundary and a further second electrical connection on a further second layer boundary, so that in this way an electric current can flow through the further electrically conductive layer in the layer plane. Thus, the heating device for heating the optically active layer can be realized in this way by a heat loss caused by the ohmic resistance of the further electrically conductive layer. In this way, a very space-saving possibility for heating the optically active layer can be realized.

It is possible that the further electrically conductive layer may be formed as a layer or a layer system for reflection or blocking of infrared (IR) or ultraviolet (UV) radiation. The blocking against IR radiation can serve in particular for vehicles to prevent the heating of the passenger compartment, while the blocking of the UV radiation in particular for the vehicle occupants for health reasons can be beneficial. In this way, the further electrically conductive layer not only has the function of a heater, but can also fulfill other protective functions.

It is also conceivable to form the further electrically conductive layer in the visible spectral range of light as transparent. In addition, it is conceivable to introduce a filling material, for example of an electrically insulating material, between the further electrically conductive layer and the first electrically conductive layer and / or the second electrically conductive layer. The filler may be an adhesive. It is also conceivable for the further electrically conductive layer to be vapor-deposited on a side of the first transparent pane and / or the second transparent pane facing the optically active layer, so that the further electrically conductive layer projects through the first and / or second transparent pane protected from external environmental influences. It is also conceivable, as with the first and second electrically conductive layers, to provide a further low-resistance element at the further electrically conductive layer at its layer boundaries, which is contacted with a respective further electrical connection in order to also provide a surface current to the further electrically conductive layer , In this case, the respective further low-resistance element can extend partially or completely over the corresponding layer boundary.

According to a further embodiment of the vehicle window pane or of the optical element, the first electrically conductive layer has a third electrical connection and the second electrically conductive layer has a fourth electrical connection, wherein an electrical alternating field into the optically active layer via the third and fourth electrical connection can be introduced in order to realize in this way by a caused by dielectric heating of the optically active layer loss heat the heater. In this way, it is thus also possible to generate heat directly in the optically active layer by dielectric losses when the alternating field is applied. In this way, in turn, a space-saving possibility for realizing a heater for the optically active layer can be achieved, in particular because the electrically conductive layers for providing a voltage for the optically active layer for a change in light transmission exert a further function, namely as a heater for the optically active layer.

According to a further embodiment of the invention, the optically active layer comprises particles suspended in a liquid or a film which can be aligned by an applied voltage, thereby changing the light transmittance of the optically active layer. In particular, such optically active layers with moving particles have a reduced function at low temperatures, since at such low temperatures, the particles are difficult or impossible to move and align with respect to their environment. Thus, the provision of a heater according to a present invention is particularly useful and advantageous here.

According to one embodiment of the optically active layer, the particles can disperse disperse in the optically active layer in a first state in which no voltage is applied, and thus prevent light transmission through the optically active layer, while in a second state in which a voltage is applied, aligning in rows between which the light can pass.

As electrically conductive layers or electrodes, in particular transparent (transparent in the visible spectral range of light) electrically conductive layers or transparent electrodes are used, which have a comparatively low absorption of electromagnetic waves in the visible light range. They may consist of special materials such as transparent electrically conductive oxides, in particular indium tin oxide (ITO).

The first and the second transparent pane, which effectively serve as carrier layers, can be produced as transparent carrier layers, for example of glass, or else of plastic materials, such as polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET) or the like.

According to a further aspect of the invention, an optical component, in particular for a vehicle window, is provided for controlling a light transmission. This optical component comprises an optically active layer whose light transmittance is reversibly changeable by applying a voltage or an electrical potential. In addition, the optical component has a first electrically conductive layer disposed on a first side of the optically active layer, and has a second electrically conductive layer disposed on a second side of the optically active layer, wherein the first and second electrically conductive layer, a voltage to the optically active layer can be applied. Furthermore, a heating device for heating the optical layer is realized in the optical component, namely by a heat loss of the at least one of the electrically conductive layers due to the ohmic resistance, or by a dielectric heating of the optically active layer by means of an alternating electric field between the first and the second second electrically conductive layer. In this way, an optical component is created, in particular for use with a carrier layer of glass or plastic (as mentioned above). The scope of application extends to vehicle windows, windows or other transparent panes whose light transmittance should be changeable. In particular, by the use of the electrically conductive layers not only for changing the light transmittance of the optically active layer, but also as heaters, leads to a particularly space-saving, simple and inexpensive realization of an optical component.

According to a further aspect of the invention, a method is provided for operating a transparent pane arrangement, in particular a vehicle window, which consists of a first transparent pane and a second transparent pane, and an optical component arranged between these panes for controlling a light transmission, wherein the optical component an optically active layer whose light transmittance is reversibly changeable by applying a voltage, having a first electrically conductive layer which is arranged on a first side of the optically active layer and has a second electrically conductive layer on a second side of the optically active Layer is arranged, wherein by the first and the second electrically conductive layer, a voltage to the optically active layer can be applied. The method comprises the following steps: In a first step, an ambient temperature of the transparent pane arrangement is determined. In a second step, the optically active layer is then heated when the determined ambient temperature is less than a predetermined temperature value. Then, particularly when a certain amount of heat has been introduced into the optical layer or has reached a certain temperature (for example, after heating for a predetermined time interval), a voltage can be applied to the optically active layer to change the light transmittance thereof. In this way, a safe operation of a transparent pane arrangement is thus ensured even at low ambient temperatures.

According to one embodiment of the method, the step of heating the optically active layer is carried out by: generating an electrical current through the first and / or second electrically conductive layer, or through a dielectric Heating the optically active layer by means of an alternating electric field between the first and the second electrically conductive layer. Thus, by using the electrodes further as a heating device, a cost-effective and device-technically simple way of heating the optically active layer can be achieved.

Advantageous embodiments of the vehicle window are, insofar as applicable to the optical component and the method, also to be regarded as advantageous embodiments of the optical component and the method, and vice versa.

In the following, exemplary embodiments of the present invention will now be explained in more detail with reference to the accompanying drawings. Show it:

1 a schematic cross-sectional view of a vehicle window for a motor vehicle to illustrate the essential components according to an embodiment of the invention;

2 a schematic representation of a motor vehicle with a vehicle window according to an embodiment of the invention (in particular 1 ), which is realized here as a transparent pane in the vehicle roof;

3 a schematic representation of an optical component for changing the light transmission with a heater according to a first embodiment of the invention;

4 an optical component for changing the light transmittance with a heater according to a second embodiment of the invention;

5 a schematic cross-sectional view of a vehicle window for a motor vehicle according to another embodiment of the invention.

It's on first 1 reference is made, in which a schematic cross-sectional view of a transparent disc assembly SA with an optical component OB for changing the light transmittance of the transparent disc arrangement is shown. Such a transparent pane arrangement can be embodied, for example, as a vehicle window or a vehicle window. As will be understood from the following explanation of the structure, the transparent pane assembly is formed as a so-called smart glass or smart window. Viewed from outside to inside, the pane arrangement SA has a first transparent pane TS1 and a second transparent pane TS2, which serve as carrier layers due to their thickness or strength. The first and second transparent disks may be formed, for example, of glass or of a plastic material. In this case, a first filling material in the form of an adhesive is provided on the first transparent pane TS1 and a second filling material FM2 is likewise provided on the second transparent pane TS2 as an adhesive. A first electrically conducting layer ELS1 is then connected to the first filling material FM1, while a second electrically conducting layer ELS2 is connected to the second filling material FM2. These two electrically conductive layers ELS1 and ELS2 serve as electrodes, and are transparent, for example, formed as a transparent, electrically conductive oxide, such as indium tin oxide. Between the two electrically conductive layers ELS1 and ELS2 then an optically active layer OAS is formed, which is reversibly changeable by applying a voltage in their light transmittance. This voltage or electrical potential for influencing the optically active layer OAS is provided by the electrically conductive layers ELS1 and ELS2, which are connected to respective electrical terminals (as shown in FIG 3 and 4 shown) are connected.

The optically active layer OAS can hereby be designed as an SPD (SPD = suspended particulate device) layer. If no voltage is present in a first state of this SPD layer, freely movable particles randomly and randomly arrange themselves in a film or a liquid of the layer. In this way, a light passage perpendicular to the optically active layer OAS, d. H. from top to bottom in the figure, largely or severely prevented or completely prevented. As shown in the figure for explanatory purposes, light LIE entering from the top to the bottom of the first transparent panel TS1 of high intensity is shown. It is assumed that the optically active layer is in the first state in which no voltage is applied. Accordingly, most of the incident light is absorbed by the optically active layer OAS, so that light LIA emerges from the second transparent disk TS2 with low intensity (i.e., reduced intensity) compared to the incident light LIE. The difference between the respective entering light intensity to be exited should be symbolized by the respective size of the arrows LIE to the smaller arrows LIA.

In a second state of the optically active layer OAS, in which a voltage is applied to the optically active layer OAS through the electrically conductive layers ELS1 and ELS2, the particles located in the optical layer are directed according to the applied voltage or the electrical current generated thereby Field out and form quasi rows, between which light perpendicular to optically active layer OAS can pass. In such a case, the light beams entering the first transparent disk TS1 would be approximately equal in intensity to the light beams emerging from the second transparent layer TS2, so that the disk arrangement SA at least shines transparent.

The optically active layer OAS with the surrounding electrically conductive layers ELS1 and ELS2 thus serve as an optical component OB for controlling the light transmission.

Due to the nature of the optically active layer OAS as a layer with movable or orientable particles, the problem here is that the mobility of these particles at low temperatures greatly decreases and thus a reaction time to a voltage applied to the optically active layer OAS at low temperatures is greatly extended. For this purpose, according to this embodiment of the invention, a heating device is integrated into the optical component, which serves to heat the optically active layer OAS, and to increase the mobility of the particles. As it is in the 3 and 4 is still shown, thereby forming the electrically conductive layers ELS1 and ELS2 together with the corresponding electrical connections respective heaters HE according to various embodiments of the invention.

It is now up 2 referenced, in which a motor vehicle FZ is shown. This motor vehicle has a passenger compartment covered with a roof DA, in which a roof window DF is provided. This roof window DF can, for example, a pane arrangement SA (see 1 ) as a vehicle window, in order to control in this way sunlight, which radiates from above through the roof window DF in the passenger compartment, in its intensity. While the roof window DF in the transparent state (in which, for example, a voltage is applied to the optically active layer OAS) allows light to penetrate virtually unhindered into the passenger compartment so as to give the user a natural feel, this sunlight also heats up the passenger compartment. If the vehicle occupants are too warm, by switching off the voltage on the optically active layer OAS, they can bring the particles provided in this layer into a disordered state, so that the light transmittance of the optically active layer is reduced or completely prevented. In this way, sunlight that hits the vehicle FZ from above is prevented from entering the passenger compartment.

It is now up 3 See, in which a first embodiment of the invention for heating the optically active layer OAS is shown. In order to identify that the optical component is a first embodiment of the intended heating device, see FIG 1 designated optical component OB in 3 designated OB1. As already in 1 The optical component OB1 comprises an optically active layer OAS with corresponding particles P. For aligning these particles P, the optical component OB1 further has a first electrically conductive layer ELS1 and a second electrically conductive layer ELS2, by means of which a voltage is applied to the optically active layer OAS can be applied. The application of this electrical voltage can take place, for example, via a first terminal A11 of the first electrically conductive layer ELS1 and via a first electrical terminal A21 of the second electrically conductive layer ELS2. In this case, the electrical connection A11 is connected via a line L11 to a control device STG and the electrical connection A21 is connected via a further line L21 to the control device STG.

According to this embodiment, the two electrically conductive layers ELS1 and ELS2 should not only have the function of aligning the particles P of the optically active layer OAS, but also serve a heating device for the optically active layer OAS. For this purpose, the first electrically conductive layer ELS1 has a second electrical connection A12, which is connected via a line L12 to the control device STG. Accordingly, the second electrically conductive layer ELS2 has a second electrical connection A22, which is connected via a line L22 to the control device STG.

If one now considers the first electrically conductive layer ELS1 closer, since the viewing direction of the figure is directed to this layer for a better explanation, then one recognizes that at a first boundary BG1 this layer, ie the boundary line running from left to right in the image, enters first low-resistance element NO1 is arranged, which is connected to the first electrical terminal A11 of the electrically conductive layer ELS1. A second low-resistance element NO2, which is connected to the second terminal A12 of the first electrically conductive layer ELS1, is provided on a second layer boundary, a boundary BG2 opposite the first layer boundary BG1. In this case, the ohmic resistance of the low-resistance elements NO1 and NO2 is less than the ohmic resistance of the electrically conductive layer ELS1. In particular, metallic materials such as copper, etc. can be used as low-resistance elements. By providing the low-resistance elements, as shown in the figure along the entire extent of the respective first and second layer boundary BG1 and BG2 is achieved that an electric current ES, in the form of a surface current through the first electrically conductive layer ELS1 flows between the low-resistance elements NO1 within the first electrically conductive layer ELS1. As a result of the heat loss due to the ohmic resistance at the first electrically conductive layer ELS1, the underlying optically active layer OAS is heated in this way so as to ensure that the particles P therein can move and align properly.

As it is in 3 is shown, it is conceivable to provide not only by the first electrically conductive layer ELS1 a surface current for heating the optically active layer OAS, but also to use the second electrically conductive layer ELS2 for heating the optically active layer OAS2. For this purpose, a corresponding structure can be used, as has just been explained with respect to the first electrically conductive layer ELS1. As it is further in 3 can be seen, terminals A21 and A22 are already provided for such a structure, which provide a power supply via corresponding lines L21 and L22.

The corresponding control of the terminals A11 and A12 or A21 and A22 via the control unit STG. This may receive instructions from a user (not shown) to cause a change in translucency. Accordingly, the controller may perform heating of the optical layer OAS before or during a change in the light transmittance, to surely ensure that a change in the light transmittance is feasible.

It is also conceivable that the control unit STG determines the ambient temperature of the optical component OB1 or a disc assembly associated therewith by means of temperature sensors connected thereto, and accordingly performs heating of the optically active layer OAS at a temperature below a predetermined temperature value , If the control device STG has heated the optically active layer OAS for a predefined time interval with a heating current via one or both electrically conductive layers ELS1 or ELS2 and thus introduced a defined amount of heat into the optically active layer OAS), then it now has the corresponding one Change the light transmission of the optical component perform.

It is now up 4 in which a second embodiment of an optical element OB2 is shown in a second possibility for realizing a heating device. This optical component OB2 in turn has an optically active layer OAS and associated electrically conductive layers ELS1 and ELS2, which are arranged in the figure above and below the optical layer OAS.

Since the structure of the optical component OB2 corresponds to that of the optical component of OB1, for a more detailed explanation of the individual components, refer to the explanation of FIG 3 directed.

The control unit STG is now designed such that it has an electrical alternating field between the two via the respective lines L11 and / or L12 with respect to the first electrically conductive layer ELS1 and the lines L21 and / or L22 with respect to the second electrically conductive layer electrically conductive layers ELS1 and ELS2 can produce. The alternating field can have a frequency in the MHz or GHz range. Since the optically active layer OAS is quasi a nonconductor in which no currents can flow, but charge carriers in the molecules or particles P of the optically active layer OAS with some delay of the direction changes of the high frequency alternating field follow, the temperature rises inside the active layer and thus there is a dielectric heating.

In particular, at low temperatures, in this way, in turn, energy can be introduced to the optically active layer by means of the electrically conductive layers ELS1 and ELS2 in order to ensure the mobility of the particles P.

As it is in 1 has been explained, it is conceivable that the control unit, for example, after receiving a user instruction first determines the temperature of the environment of the optical component OB2 and accordingly at a temperature below a predetermined minimum temperature, first the optically active layer OAS, as just described, heated and then a Performs voltage change over the electrically conductive layers, for example, over a longer period permanently applies voltage across the first and the second electrically conductive layers ELS1 and ELS2, to effect a change in the light transmission.

Since the optically active layer of the optical components OB1 and OB2 is only one layer in the region of approximately 100 μm, only a small energy input through one of the layers is sufficient for heating this layer 3 and 4 illustrated method.

It is now up 5 in which a schematic cross-sectional view of a transparent pane arrangement SA5 with an optical component OB for changing the light transmittance of the transparent pane arrangement, as in FIG 1 is shown. This in 5 illustrated Embodiment of a transparent disc assembly SA5 substantially corresponds to the disc assembly SA of 1 , Mark is another electrically conductive layer WE1 and WE2 each on the inside of a transparent plate TS1 and TS2.

Such a transparent pane arrangement SA5 can again be designed as a vehicle window or a vehicle window, for example. As will be understood from the following explanation of the structure, the transparent pane assembly is formed as a so-called smart glass or smart window. Viewed from outside to inside, the pane arrangement SA5 has a first transparent pane TS1 and a second transparent pane TS2, which serve as carrier layers due to their thickness or strength. The first and second transparent disks may be formed, for example, of glass or of a plastic material.

On the inside of the respective transparent panes TS1 and TS2, an electrically conductive layer WE1 or WE2 is now formed, in particular vapor-deposited, as a layer for reflection or blocking of infrared (IR) or ultraviolet (UV) radiation. It is conceivable that according to an embodiment hereof only one of the layers WE1 or WE2 is formed. The layers WE1 and WE2 should be transparent in the visible spectral range of light.

Furthermore, a first filling material FM1 in the form of an adhesive is provided on the first transparent pane TS1 or the layer WE1, and a second filling material FM2 is likewise provided on the second transparent pane TS2 or the layer WE2 as an adhesive. A first electrically conducting layer ELS1 is then connected to the first filling material FM1, while a second electrically conducting layer ELS2 is connected to the second filling material FM2. These two electrically conductive layers ELS1 and ELS2 serve as electrodes, and are transparent, for example, formed as a transparent, electrically conductive oxide, such as indium tin oxide. Between the two electrically conductive layers ELS1 and ELS2 then an optically active layer OAS is formed, which is reversibly changeable by applying a voltage in their light transmittance. This voltage or electrical potential for influencing the optically active layer OAS is provided by the electrically conductive layers ELS1 and ELS2, which are connected to respective electrical terminals (for example as shown in FIG 3 and 4 shown) are connected.

The optically active layer OAS can hereby be designed as an SPD (SPD = suspended particulate device) layer. If no voltage is present in a first state of this SPD layer, freely movable particles randomly and randomly arrange themselves in a film or a liquid of the layer. In this way, a light passage perpendicular to the optically active layer OAS, d. H. from top to bottom in the figure, largely or severely prevented or completely prevented. As shown in the figure for explanatory purposes, light LIE entering from the top to the bottom of the first transparent panel TS1 of high intensity is shown. It is assumed that the optically active layer is in the first state in which no voltage is applied. Accordingly, most of the incident light is absorbed by the optically active layer OAS, so that light LIA emerges from the second transparent disk TS2 with low intensity (i.e., reduced intensity) compared to the incident light LIE. The difference between the respective entering light intensity to be exited should be symbolized by the respective size of the arrows LIE to the smaller arrows LIA.

In a second state of the optically active layer OAS, in which a voltage is applied to the optically active layer OAS through the electrically conductive layers ELS1 and ELS2, the particles located in the optical layer are directed according to the applied voltage or the electrical current generated thereby Field and form quasi rows, between which light can pass perpendicular to the optically active layer OAS. In such a case, the light beams entering the first transparent disk TS1 would be approximately equal in intensity to the light beams emerging from the second transparent layer TS2, so that the disk arrangement SA at least shines transparent.

The optically active layer OAS with the surrounding electrically conductive layers ELS1 and ELS2 thus serve as an optical component OB for controlling the light transmission.

Due to the nature of the optically active layer OAS as a layer with movable or orientable particles, the problem here is that the mobility of these particles at low temperatures greatly decreases and thus a reaction time to a voltage applied to the optically active layer OAS at low temperatures is greatly extended.

For this purpose, according to this embodiment of the invention, it is possible to integrate a heating device in the optical component, which serves to heat the optically active layer OAS, and to increase the mobility of the particles. As it is in the 3 and 4 is still shown, thereby forming the electrically conductive layers ELS1 and ELS2 together with the corresponding electrical connections respective heaters HE according to various embodiments of the invention.

However, it is also possible, in addition to or instead of a heating device in the optical component, on at least one of the electrically conductive layers WE1 or WE2 (or in both layers WE1 and WE2) a further first electrical connection to a first respective layer boundary and a further second electrical Connection to provide a further second respective layer boundary (the layers WE1 and / or WE2), so that in this way an electric current can flow through the layer WE1 and / or WE2 in the layer plane. Thus, in this way, by a loss due to the ohmic resistance of the layer WE1 and / or WE2 heat, the heater for heating the disc assembly SA5 and thus also the optically active layer can be realized.

Furthermore, it is conceivable to form the electrical connections in such a way that they extend at least over a certain subregion of the layer boundaries, so that in this way a surface current can be generated within a corresponding layer WE1 and / or WE2, through the heat loss of which the pane arrangement SA5 and Thus, the optically active layer is heated.

In summary shows 5 a vehicle windshield or disk arrangement SA5, in particular for a motor vehicle with a first transparent disk TS1 and a second transparent disk TS2, an optical component OB arranged between the first and the second transparent disk for controlling a light transmission, comprising an optical active layer OAS whose Light transmittance is reversibly changeable by applying a voltage, a first electrically conductive layer ELS1, which is arranged on a first side of the optically active layer OAS and a second electrically conductive layer ELS2, which is arranged on a second side of the optically active layer OAS, wherein a voltage can be applied to the optically active layer by the first and the second electrically conductive layer. Furthermore, the disk arrangement comprises a heating device HE for heating the optically active layer OAS, which is realized either by the first and / or second electrically conductive layer (by generating an electric current through the first and / or second electrically conductive layer or by a dielectric heating the optically active layer by means of an alternating electric field between the first and the second electrically conductive layer). However, the heating device may additionally or alternatively be realized by a further electrically conductive layer WE1, WE2, the on one of the optically active layer OAS side facing away from the first ELS1 and / or second ELS2 electrically conductive layer (or on the inside of a respective transparent disc TS1 and / or TS2) is arranged. This further electrically conductive layer has a corresponding first electrical connection at a first layer boundary and a corresponding second electrical connection at a second layer boundary for conducting an electrical current through the further electrically conductive layer WE1, WE2, in order in this way to pass through the resistive layer Resistance conditional heat loss to realize the heater. The further electrically conductive layer may be formed as a layer or a layer system for reflection or blocking of infrared (IR) or ultraviolet (UV) radiation. In addition, it is conceivable to introduce a filling material, for example of an electrically insulating material, between the further electrically conductive layer and the first electrically conductive layer and / or the second electrically conductive layer. The filler may be an adhesive.

Claims (10)

 Vehicle window (SA, DF), in particular for a motor vehicle (FZ), having the following features: A first transparent disk (TS1) and a second transparent disk (TS2); An optical component (OB, OB1, OB2) arranged between the first and the second transparent pane for controlling a light transmission, comprising: An optical active layer (OAS) whose light transmittance is reversibly changeable by applying a voltage, - A first electrically conductive layer (ELS1), which is arranged on a first side of the optically active layer (OAS) and - A second electrically conductive layer (ELS2), which is arranged on a second side of the optically active layer (OAS), wherein by the first and the second electrically conductive layer, a voltage to the optically active layer can be applied; A heater (HE) for heating the optically active layer (OAS). The vehicle window according to claim 1, wherein the first (ELS1) and / or the second (ELS2) electrically conductive layer has a respective first electrical terminal (A11, A21) at a first layer boundary (BG1) and a respective second terminal (A12, A22). at a second layer boundary for conducting an electric current (ES) through the respective electrically conductive layer (ELS1, ELS2), in order in this way by a through the Ohmic resistance heat loss to realize the heater. Vehicle window according to claim 2, wherein the first (ELS1) and / or the second (ELS2) electrically conductive layer at the respective first layer boundary (BG1) connected to the first electrical connection (A11) and at least over a certain portion of the layer boundary (BG1) extending first low-resistance element (NO1), and at the respective second layer boundary (BG2) connected to the second electrical connection (A12) and at least over a certain portion of the layer boundary expands second low-resistance element (NO2), so to generate a surface current (ES) between the first and the second low-resistance element (NO1, NO2). Vehicle windscreen according to claim 1, wherein the first (ELS1) and / or the second (ELS2) electrically conductive layer on a side facing away from the optically active layer (OAS) has a further electrically conductive layer on which a further first electrical connection to another the first layer boundary and a further second electrical connection are provided on a further second layer boundary for conducting an electrical current through the further electrically conductive layer, in order in this way to realize the heating device by means of a heat loss caused by the ohmic resistance. The vehicle window according to claim 1, wherein the first electrically conductive layer has a third electrical connection (A11, A12) and the second electrically conductive layer has a fourth electrical connection (A21, A22), wherein an alternating electric field in FIG the optical active layer can be introduced in order to realize in this way by a caused by dielectric heating of the optically active layer (OAS) loss heat the heater. A vehicle windshield according to any one of claims 1 to 5, wherein the optically active layer (OAS) comprises particles (P) suspended in a liquid or film which can be aligned by an applied voltage to thereby increase the light transmittance of the optically active layer (OAS ) to change. Vehicle windscreen according to claim 6, wherein in a first state in which no voltage is applied, the particles disperse in the optically active layer (OAS) and thus prevent a light transmission through the active layer, while a second state in which a voltage is applied, aligning in rows between which the light (LIE) can pass. Optical component (OB, OB1, OB2), in particular for a vehicle window (SA), comprising: - An optical active layer (OAS), the light transmittance is reversibly changeable by applying a voltage; A first electrically conductive layer (ELS1) disposed on a first side of the optically active layer (OAS), and A second electrically conductive layer (ELS2) arranged on a second side of the optically active layer (OAS), wherein a voltage to the optically active layer (OAS) can be applied by the first and the second electrically conductive layer; Wherein a heating device (HE) for heating the optically active layer (OAS) By a loss heat due to the ohmic resistance in at least one of the electrically conductive layers (ELS1, ELS2) or - Is realized by a dielectric heating of the optical active layer (OAS) by means of an alternating electric field between the first and the second electrically conductive layer. Method for operating a transparent pane arrangement (SA), in particular a vehicle window, comprising a first transparent pane (TS1) and a second transparent pane (TS2) and an optical component (OB, OB1, OB2) arranged between these for controlling a light transmission, comprising an optically active layer (OAS) whose light transmittance is reversibly changeable by applying a voltage, a first electrically conductive layer (ELS1) disposed on a first side of the optically active layer and a second electrically conductive layer (ELS2) is arranged on a second side of the optically active layer, wherein a voltage can be applied to the optically active layer (OAS) through the first and the second electrically conductive layer (ELS1, ELS2), the method comprising the following steps: Determining an ambient temperature of the transparent pane arrangement (SA), - Heating the optically active layer (OAS), when the determined ambient temperature is less than a predetermined temperature. The method of claim 9, wherein the step of heating the optically active layer (OAS) is performed: - by generating an electric current (ES) through the first and / or second electrically conductive layer (ELS1) or - by a dielectric heating of the optically active layer (OAS) by means of an electrical Alternating field between the first and the second electrically conductive layer (ELS1, ELS2).

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