Composite pane with electrically controllable optical properties

Abstract

The present invention relates to a composite pane with electrically controllable optical properties, which comprises an electrically controllable functional element (10) which comprises, in a specific order, a first carrier film (12), a first planar electrode (14), an active layer (11) or layer sequence with electrically controllable optical properties, a second planar electrode (15), and a second carrier film (13). In a first contact area, the second carrier film (13), the second planar electrode (15), and the active layer (11) or layer sequence are removed, and the first planar electrode (14) is electrically conductively connected to a current collecting rail (21). In a second contact area, the first carrier film (12), the first planar electrode (14), and the active layer (11) or layer sequence are removed, and the second planar electrode (15) is electrically conductively connected to at least one current collecting rail (21; 22.1, 22.2, 22.3). According to the invention, the first contact area and the second contact area are arranged on opposite sides of the functional element (10), and the current collecting rail (21) of the first planar electrode (14) extends from the first contact area to the opposite side of the functional element (10) in the connection area, with the second carrier film (13), the second planar electrode (15) and the active layer (11) or layer sequence being removed in the connection area.

Description

[Technical Field]

[0001] The present invention relates to composite panes having electrically controllable optical properties and uses thereof. [Background technology]

[0002] Composite panes with electrically controllable optical properties are known. They comprise a functional element having an active layer or layer sequence between two planar electrodes, the optical properties of which can be changed by applying an electric voltage to the planar electrodes. Examples of such functional elements include SPD (suspended particle device) functional elements, which are known, for example, from EP 0 876 608 A1 and WO 2011 / 033313 A1. By applying a voltage, the transmission of visible light can be controlled by the SPD functional element. Another example is PDLC (polymer-dispersed liquid crystal) functional elements, which are known, for example, from DE 10 2008 026 339 A1. The active layer contains liquid crystals embedded in a polymer matrix. When no voltage is applied, the liquid crystals align in a random manner, which results in strong scattering of light passing through the active layer. When a voltage is applied to the planar electrodes, the liquid crystals align in a common direction, increasing the transmittance of light through the active layer. PDLC functional elements operate primarily by increasing scattering rather than reducing total transmission, so that clear vision can be prevented or anti-glare protection can be achieved. Furthermore, electrochromic functional elements are known, for example from US 2012 / 0026573, WO 2010 / 147494, EP 1 862 849, and WO 2012 / 007334, in which the change in transmission is the result of an electrochemical process induced by an applied voltage.

[0003] Such composite panes can be used, for example, as vehicle window panes, and their light transmission behavior can be electrically controlled. They can also be used, for example, as roof panes to reduce direct sunlight or disturbing reflections. Such roof panes are known, for example, from German Patent Application Publication No. 10043141 and European Patent Application Publication No. 3456913. Windshields have also been proposed in which electrically controllable sunscreens are realized by switchable functional elements, thereby replacing conventional mechanically foldable sunscreens in automobiles. Windshields with electrically controllable sunscreens are known, for example, from German Patent Application Publication No. 102013001334, German Patent Application Publication No. 102005049081, German Patent Application Publication No. 102005007427, and German Patent Application Publication No. 102007027296. Such composite panes can be used not only in the automotive sector but also, for example, in building glazing or interior window panes.

[0004] The electrically controllable functional element is typically provided as a multilayer film and embedded in the middle layer of the composite pane. The multilayer film consists of two carrier films, typically based on PET, on which planar electrodes, typically based on ITO, are deposited, with an active layer or layer sequence between them. For electrical contact, a contact area is typically created for each planar electrode by removing the opposite carrier film along with the other planar electrode and the active layer or layer sequence. This exposes the planar electrode in the contact area and allows electrical contact via current collecting rails, typically copper foil strips. Electrical conductors are connected to the current collecting rails and extend beyond the side edges of the composite pane to connect the functional element to an external voltage source.

[0005] The contact areas of the two planar electrodes are typically formed on opposite sides of the functional element, which is advantageous for the optical behavior of the functional element, especially because it ensures relatively uniform and possibly relatively fast switching behavior. However, this fact leads to manufacturing drawbacks. Since the process steps for electrical contact are performed on opposite sides of the functional element, manufacturing costs increase. In particular, a relatively long electrical conductor is required, which is applied to the thermoplastic film of the intermediate layer of the composite pane, for example as a metal wire, using a plotter, which is time-consuming.

[0006] German Utility Model No. 202018102520 discloses a composite pane with electrically controllable functional elements, the contact areas of which are arranged on opposite sides of the functional element. The current collecting rails have an L-shape, so that the current collecting rails of a first planar electrode extend from the first contact area to the opposite side of the functional element in the connection area. This allows an electrical conductor to be connected to two current collecting rails on the same side of the functional element. The second carrier film, the second planar electrode, and the active layer or layer sequence must be removed in the connection area to place the current collecting rail on the first planar electrode. Since the second planar electrode is directly adjacent to the connection area where the first planar electrode is exposed, there is a risk that the second planar electrode will come into contact with the first planar electrode, the current collecting rail of the first planar electrode, or their electrical contacts and cause a short circuit. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention addresses the problem of providing an improved composite pane with electrically controllable optical properties, which is particularly relatively easy to fabricate, and in which short circuits are avoided. [Means for solving the problem]

[0008] This problem is solved according to the invention by a composite pane with electrically controllable optical properties according to independent claim 1. Advantageous embodiments result from the dependent claims.

[0009] The present invention is based on the approach of extending one current collecting rail and connecting it in the connection area to the opposite side of the functional element, on which the other current collecting rail is located. The electrical connections of both current collecting rails can then be made on the same side of the functional element, which reduces production costs. A relatively small number of long electrical conductors are required, which allows the design, for example using a plotter, to be implemented relatively quickly. These are major advantages of the present invention.

[0010] The composite pane of the present invention having electrically controllable optical properties comprises an outer pane and an inner pane connected to each other via a thermoplastic intermediate layer. The composite pane also comprises an electrically controllable functional element embedded within the intermediate layer. The functional element comprises, in a specific order, a first carrier film, a first planar electrode, an active layer or layer sequence having electrically controllable optical properties, a second planar electrode, and a second carrier film. The carrier film, planar electrode, and active layer / layer sequence are typically arranged substantially parallel to the surfaces of the outer pane and the inner pane.

[0011] The functional element has a first contact area provided for electrical connection of the first planar electrode. In the first contact area, the second carrier film, the second planar electrode, and the active layer or layer sequence are removed. The first carrier film and the first planar electrode remain in the first contact area, so that the first planar electrode is exposed and can be electrically contacted. In the first contact area, the first planar electrode is electrically connected to a current collecting rail. For this purpose, the current collecting rail is arranged on the first planar electrode in the first contact area.

[0012] The functional element also has a second contact area provided for the electrical connection of a second planar electrode. In the second contact area, the first carrier film, the first planar electrode, and the active layer or layer sequence are removed. The second carrier film and the second planar electrode remain in the second contact area, so that the second planar electrode is exposed and can be electrically contacted. In the second contact area, the second planar electrode is electrically connected to at least one current collecting rail. For this purpose, at least one current collecting rail is arranged on the second planar electrode in the second contact area.

[0013] According to the invention, the first and second contact areas are arranged on opposite sides of the functional element. The current collecting rails of the first planar electrode (i.e., the current collecting rails that are arranged in the first contact area on the first planar electrode and are connected to and electrically conductively connected thereto) extend from the first contact area to the opposite side of the functional element in the connection area. The connection area is formed identically to the first contact area in that the second carrier film, the second planar electrode, and the active layer or layer sequence are removed.

[0014] The width of the contact area is preferably 3 mm to 20 mm, particularly preferably 5 mm to 10 mm. The width of the connection area is preferably 3 mm to 20 mm, particularly preferably 5 mm to 10 mm. The width is the dimension perpendicular to the intended extension direction of the current collecting rail.

[0015] The functional elements of the present invention are divided into the following areas: at least one active region, in which both carrier films, both planar electrodes and an active layer or layer sequence are present, the optical properties of which can be electrically controlled; - first and second contact areas, and - Connection area.

[0016] The current collecting rail of the first planar electrode and at least one current collecting rail of the second planar electrode (i.e., one or more current collecting rails arranged in, connected to and electrically conductively connected to the second contact area on the second planar electrode) are connected to a voltage source via an electrical conductor, which preferably connects the current collecting rail of the first planar electrode and at least one current collecting rail of the second planar electrode on the same side of the functional element.

[0017] The contact areas are preferably formed immediately adjacent to the lateral edges of the functional element, the first and second contact areas being immediately adjacent to opposite portions of the lateral edges of the functional element.

[0018] In one embodiment, a connection region is also formed immediately adjacent to a side end portion of the functional element, the side end portion extending between the side end portion having the first and second contact regions, the connection region being connected to one end of the first contact region and extending therefrom to the opposite side of the functional element.

[0019] In a further embodiment, the connection region is not formed directly adjacent to the side edge of the functional element. It extends within a central region of the functional element, adjacent to both sides of the active area of ​​the functional element. The connection region is connected to a portion of the first contact region located between the terminal ends and extends from there to the opposite side of the functional element. The connection region divides the second planar electrode and the second contact region into two portions, each portion assigned to an active area of ​​the functional element.

[0020] The functional element is not limited to a particular shape. Typically, the functional element has an at least approximately quadrangular, particularly at least approximately rectangular, shape (relative to a plan view looking through the composite pane). The functional element has four corners and four sides, with adjacent sides connected to each other by a corner. The term "approximately" means that the shape can deviate from an ideal geometric square or rectangle in that the sides do not have to be straight and can, for example, be convexly or concavely curved or wavy, independently of each other. The contact areas are located on two opposite sides, particularly at the side edges or directly adjacent to said sides. The two other sides extend between the sides having the contact areas, particularly substantially perpendicular to them. The connection area preferably extends substantially parallel to these other sides, and can be adjacent to one of the two or extend within the area between these other sides.

[0021] The second contact area and the connection area can overlap, so to speak, in that a portion of the functional element is cut out, i.e., the carrier film on which the planar electrode is located is removed in the overlapping area, since the active layer or layer sequence alone would not be stable. Alternatively, the second contact area and the connection area can be directly adjacent to each other in the plan view of the functional element or composite pane, in that case the cutting lines for removing the first carrier film in the second contact area and the cutting lines for removing the second carrier film in the connection area are arranged in layers in the overlapping area in the plan view.

[0022] However, in a preferred embodiment, the second contact area and the connection area do not overlap. The second contact area and the connection area do not adjoin each other in the sense described above. Instead, when the functional element or composite pane is viewed from above, at least one intermediate area exists between the second contact area and the connection area. Therefore, the cutting line for removing the first carrier film in the second contact area is led to the side edge of the functional element before reaching the connection area. In this intermediate area, the first carrier film, the first planar electrode, and the active layer or layer sequence are not removed and extend, in particular, to the side edge of the functional element on which the electrical connection is to be made. The second carrier film and the second planar electrode also extend in the intermediate area to the side edge of the functional element on which the electrical connection is to be made.

[0023] In a preferred variant, within the intermediate region, a part of the second planar electrode adjacent to the connection region in plan view is electrically isolated from the rest of the second planar electrode by at least one isolation line. The at least one isolation line preferably extends from the side of the functional element with the second contact region to the opposite first contact region. The at least one isolation line divides the second planar electrode into at least one active region, which actually functions as a planar electrode and applies a voltage to the active layer / layer sequence, and at least one region electrically isolated therefrom and adjacent to the connection region in plan view. The electrical isolation of the part of the second planar electrode adjacent to the connection region particularly reduces the risk of short circuits. This is advantageous because this portion of the second planar electrode is directly adjacent to the connection area where the first planar electrode is exposed and where the current collecting rail runs, which means that there is a risk that this portion of the second planar electrode will come into contact with the first planar electrode, the current collecting rail of the first planar electrode, or their electrical contact points and cause a short circuit.

[0024] At least one interruption line for interrupting the area of ​​the second planar electrode adjacent to the connection area has a width (line width) of, for example, 5 μm to 500 μm, in particular 20 μm to 200 μm, and is preferably introduced into the second planar electrode by laser irradiation.

[0025] If the connection area is adjacent to a side edge of the functional element, a single interruption line is sufficient, which divides the second planar electrode into an active area and an electrically isolated area adjacent to the connection area. If the connection area is not adjacent to a side edge of the functional element, two interruption lines are used, which divide the second planar electrode into two active areas and two electrically isolated areas, each adjacent to the connection area on one side.

[0026] In one embodiment of the present invention, the second planar electrode (or each of its active areas, if it is divided into two parts by a connecting area not adjacent to the lateral edges of the functional element and / or if the area of ​​the second planar electrode adjacent to the connecting area is separated from at least one active area by at least one separating line in at least one intermediate area) is formed as a continuous, uninterrupted layer. It is not divided into a plurality of electrically separated segments by separating lines. The functional element (or its active area) may then be brought into a uniform optical state by an applied electrical voltage; there are no independently controllable switching areas. The second planar electrode is preferably electrically conductively connected to a single current collecting rail in the second contact area. If the second planar electrode is divided into two parts by a connecting area not adjacent to the lateral edges of the functional element, each section is preferably electrically conductively connected to a single current collecting rail. The second planar electrode and the first planar electrode are electrically connected to a voltage source, whereby an electrical voltage can be applied between the second planar electrode on the one hand and the first planar electrode on the other hand, thereby controlling the optical properties of the active layer / layer sequence located therebetween.

[0027] In a further embodiment of the invention, the second planar electrode (or at least one, preferably each, of its active areas, if the second planar electrode is divided into two parts by a connection area not adjacent to a lateral edge of the functional element and / or if the area of ​​the second planar electrode adjacent to the connection area is separated from at least one active area by at least one separation line in at least one intermediate region) is divided into at least two separate electrode segments by at least one separation line. Each electrode segment is electrically connected to a (separate or separate) current collecting rail. Each electrode segment of the second planar electrode and the first planar electrode (or its active area) are electrically connected to a voltage source, whereby an electric voltage can be applied independently between each electrode segment of the second planar electrode and the first planar electrode (or its active area), thereby controlling the optical properties of the part of the active layer / layer sequence located therebetween. In this way, multiple independent switching areas can be realized, whose optical properties can be electrically controlled independently of each other.

[0028] Thus, in this embodiment, the second planar electrode has at least two segments (electrode segments), which are separated from each other by a cut-off line. The second planar electrode may be subdivided into multiple segments by multiple cut-off lines. Each electrode segment forms a switching area of ​​the composite pane. The number of electrode segments may be freely selected by a person skilled in the art according to individual needs. In a preferred embodiment, the cut-off lines extend substantially parallel to each other and from one side edge of the planar electrode to the opposite side edge. However, any other geometric shape is also conceivable.

[0029] The separation lines between the segments of the second planar electrode have a width of, for example, 5 μm to 500 μm, particularly 20 μm to 200 μm. These are preferably introduced into the second planar electrode by laser irradiation. The width of the segments, i.e., the distance between adjacent separation lines, can be appropriately selected by those skilled in the art according to individual requirements.

[0030] The electrode segments of the second planar electrode are electrically connected independently to a voltage source, so that a second electrical potential (constant over time in the case of a DC voltage or variable over time in the case of an AC voltage) can be applied to each electrode segment (independently of the other electrode segments), which can also be referred to as a switching potential. The first planar electrode (or its active area) is also electrically connected to a voltage source, so that a first electrical potential, which can also be referred to as a reference potential ("ground"), can be applied to the entire first planar electrode (or its active area). If the first and second potentials are identical, no voltage is generated between the electrodes in the respective switching areas (0% switching state). On the other hand, if the first and second potentials are different, a voltage is applied between the electrodes in the respective switching areas to create a finite switching state (up to 100% switching state, corresponding to a maximum change in the optical properties of the active layer / layer sequence).

[0031] The first planar electrode is preferably formed as a continuous, uninterrupted layer, and therefore has no interrupted lines dividing it into separate segments. A uniform potential is preferably applied to the first planar electrode.

[0032] An interruption line is understood to mean a linear or linear area where the material of the planar electrode is absent, by which adjacent segments are materially separated from one another and are therefore electrically interrupted from one another. This means that there is no direct electrical connection between the segments, although the segments may to a certain extent be indirectly connected to one another in an electrically conductive manner via the active layers in contact with them.

[0033] The current collecting rails serve to distribute the electrical contact of each planar electrode with the voltage source over a relatively large contact area and to introduce or discharge current over as wide a width as possible. They are also called "bus bars." The current collecting rails preferably have a thickness of 2 mm to 20 mm, particularly preferably 4 mm to 9 mm. The width of the current collecting rails is preferably smaller than the width of the contact and connection areas, for example by about 1 mm. The current collecting rails are preferably formed from an electrically conductive foil (especially as a strip or part of an electrically conductive foil). The foil is particularly preferably a metal foil, in particular a copper foil. The copper foil can be coated with tin. The metal foil has a thickness of, for example, 0.02 mm to 0.2 mm, preferably 0.05 mm to 0.1 mm. However, polymer carrier films may also be used, which are provided with an electrically conductive coating, for example a silver coating.

[0034] The current collecting rails may be integrally formed (i.e., from a single strip or a single section of electrically conductive foil) independently of one another, or may be formed in multiple pieces (i.e., from a combination of multiple strips or sections of electrically conductive foil). In a preferred embodiment, the current collecting rail of the second planar electrode is integrally formed (especially as a strip of electrically conductive foil), and the current collecting rail of the first planar electrode is integrally formed or multiple pieces. In the case of a multiple piece design, the two parts of the current collecting rail on the contact area and the connection area are preferably integrally formed, respectively, and connected to each other, for example, placed one on top of the other, soldered, or glued in an electrically conductive manner. The current collecting rail of the first planar electrode typically has an L-shape (when the connection portion is adjacent to a side edge of the functional element) or a T-shape (when the connection portion is not adjacent to a side edge of the functional element). In an integral design, a T-shaped or L-shaped section of electrically conductive foil may be used, or a strip of electrically conductive foil may be folded into a T-shape or an L-shape.

[0035] The current collecting rails are electrically conductively connected to the associated planar electrodes. For example, the current collecting rails may simply be placed on the planar electrodes, soldered to the planar electrodes, or connected to the planar electrodes via an electrically conductive adhesive. In an advantageous embodiment, an electrical contact layer may be arranged between the planar electrodes and the current collecting rails, thereby improving the electrical contact. The contact layer may be formed, for example, as a silver-containing paste having a thickness of 0.01 mm to 0.2 mm, preferably 0.02 mm to 0.1 mm, in particular 0.02 mm to 0.05 mm.

[0036] Electrical conductors are connected to the current collecting rails of the first planar electrode and to the current collecting rails of the second planar electrode or to the current collecting rails of various segments of the second planar electrode, and extend beyond the side edges of the composite pane for connection to an external voltage source. The conductors may be unitary or multiple. The conductors may be, for example, metal wires, metal foils, and / or electrical cables extending from each planar electrode beyond the side edges of the composite pane.

[0037] In an advantageous embodiment of the invention, the conductor comprises a ribbon conductor extending beyond the side edge of the composite pane and connected to the current collecting rails of the planar electrodes via electrical conductors. The composite pane then comprises a ribbon conductor arranged laterally at a predetermined distance from the functional element, in particular on the side having the second contact area where the electrical connection is made, and extending beyond the side edge of the composite pane. The current collecting rails of the first planar electrode and at least one current collecting rail of the second planar electrode are connected to the ribbon conductor via electrical conductors. The ribbon conductor advantageously makes the electrical connection of the functional elements relatively easy, in particular by eliminating the need to lay multiple separate cables for each individual current collecting rail.

[0038] The ribbon conductor has a plurality of electrically conductive tracks, in particular each formed from a strip of metal foil (e.g. copper foil). Preferably, all electrically conductive tracks are connected by a polymer sheath or carrier layer to form a component. A first planar electrode is assigned a conductive track to which it is connected via an electrical conductor. A second planar electrode is - it is connected via an electrical conductor, a conductive track is assigned, or - a plurality of conductive tracks are allocated, where each segment of the second planar electrode is connected to a (separate) track via an electrical conductor, so that each electrode segment is connected to exactly one track and each track is connected to exactly one electrode segment. The ribbon conductor may of course have tracks ("blind tracks") that are not connected to any electrode or electrode segment and are not used for electrical connections.

[0039] In a preferred embodiment of the invention, an electrical contact element is connected to each current collecting rail. In other words, the current collecting rails are each provided with an electrical contact element, where the contact element is, for example, placed on the current collecting rail and soldered thereto or glued with an electrically conductive adhesive. The electrical contact element is preferably formed from an electrically conductive foil, in particular a copper foil. The copper foil can be coated with tin. The metal foil has a thickness of, for example, 0.02 mm to 0.2 mm, preferably 0.05 mm to 0.1 mm. Alternatively, the contact element can be designed as, for example, a carrier film with an electrically conductive coating, for example a silver coating. The contact element preferably has at least a portion extending from the current collecting rail beyond the side edge of the functional element, in particular substantially perpendicular to the extension direction of the current collecting rail. This portion is preferably connected to a ribbon conductor. The contact element can, for example, have a strip or T-shape.

[0040] The contact elements may be directly connected to the ribbon conductors, or alternatively, the contact elements may be indirectly connected to the ribbon conductors via electrical wires, which are preferably metal wires, electrical cables, or printed lines.

[0041] Contact elements may also be used when the electrical wires themselves extend beyond the side edges of the composite pane, ie, when there is no common ribbon conductor.

[0042] The electrically controllable functional element is a multilayer or functional film having the actual active layer or layer sequence and planar electrodes between two carrier films. Such multilayer films can be purchased commercially, cut to a certain size and shape, and laminated to a composite pane, where they are preferably connected to the outer and inner panes via respective thermoplastic connecting layers.

[0043] The first and second carrier films are formed, for example, based on polyethylene terephthalate (PET), polypropylene, polyvinyl chloride, fluorinated ethylene propylene, polyvinylidene fluoride, or ethylene tetrafluoroethylene, preferably based on PET. The thickness of the carrier films is preferably 10 μm to 200 μm.

[0044] The lateral edges of the functional element can be sealed, for example by fusing the carrier layer, with a (preferably polymeric) tape or polymer film, in this way the active layer can be protected, in particular from the diffusion of components of the intermediate layer (especially plasticizers) into the active layer, which diffusion could cause degradation of the functional element.

[0045] The first and second planar electrodes are preferably transparent, which in the context of the present invention means that they have a light transmittance of at least 50%, preferably at least 70%, particularly preferably at least 80% in the visible spectral range. The planar electrodes preferably contain at least one metal, metal alloy, or transparent conductive oxide (TCO). They may be based, for example, on silver, gold, copper, nickel, chromium, tungsten, indium tin oxide (ITO), gallium- or aluminum-doped zinc oxide, and / or fluorine- or antimony-doped tin oxide, and are preferably based on silver or ITO. The planar electrodes preferably have a thickness of 10 nm to 2 μm, particularly preferably 20 nm to 1 μm, and most preferably 30 nm to 500 nm.

[0046] The active layer or layer sequence has variable optical properties that can be controlled by applying a voltage to the active layer via planar electrodes. In the context of the present invention, an electrically controllable optical property is understood to mean, in particular, such a property that is continuously controllable. However, in principle, it is also conceivable that the electrically controllable optical property can only be switched between two discrete states (or between more than two discrete states). The optical property in particular relates to light transmittance and / or scattering behavior.

[0047] Depending on the type of functional element, there may be a single active layer or a sequence of active layers (i.e. several different layers which together provide variable optical properties). Various types of functional elements may be used, in preferred embodiments the functional elements are functional elements based on liquid crystal technology (in particular PDLC functional elements), SPD functional elements or electrochromic functional elements.

[0048] Functional elements based on liquid crystal technology comprise an active layer containing liquid crystals. The liquid crystals can be oriented by applying a voltage to planar electrodes, which is the basis for the electrical control of the optical properties. In particular, the following functional elements based on liquid crystal technology are common: - PDLC (Polymer Dispersed Liquid Crystal) functional element: the active layer contains liquid crystal droplets in a polymer matrix. When the liquid crystal is aligned in an electric field, the state is transparent and not light scattering; when the liquid crystal is not aligned without an electric field, the state is translucent and strongly light scattering. - PNLC (Polymer Network Liquid Crystal) functional element: the active layer contains liquid crystals embedded in a polymer network. With no voltage applied, the liquid crystals are oriented and the state is transparent and not light scattering. When an electric voltage is applied, structural changes occur, which lead to strong scattering in the liquid crystals, which makes the state translucent and strongly light scattering. - Guest-host functional element: The active layer contains dichroic dye molecules (guest) dispersed in a liquid crystal (host). The liquid crystal is oriented in an electric field, which affects the orientation of the dye molecules, resulting in a change in the transmission level (coloration level) and color.

[0049] SPD (Suspended Particle Device) functional elements have an active layer containing suspended particles. The absorption of light by the active layer can be changed by applying a voltage to planar electrodes, which results in a change in the orientation of the suspended particles.

[0050] An electrochromic functional element comprises a sequence of active layers (electrochromic layer sequence) between planar electrodes, arranged in the following order: ion storage layer, electrolyte layer and electrochromic layer. The electrochromic layer is the actual carrier of the electrically controllable optical properties. It is an electrochemically active layer, the degree of light transmittance of which depends on the degree of ion storage. Ions (e.g. H + , Li + , Na + , or K +The electrochromic layer (ions) is stored in and provided by the ion storage layer. The electrolyte layer serves to spatially separate the electrochromic layer from the ion storage layer and facilitate ion migration. When a DC voltage of appropriate polarity is applied to the planar electrodes, ions migrate from the ion storage layer through the electrolyte layer and into the electrochromic layer, causing the optical properties (color, light transmittance) of the electrochromic layer to change according to the amount of ions migrated into the layer. When a DC voltage of opposite polarity is applied to the planar electrodes, ions migrate from the electrochromic layer through the electrolyte layer and back into the ion storage layer, causing the optical properties of the electrochromic layer to change in an inverse manner. When no voltage is applied to the planar electrodes, the current state remains stable. Suitable electrochromic layers contain electrochromic materials, such as inorganic oxides (e.g., tungsten oxide or vanadium oxide), complex compounds (e.g., Prussian blue), or conductive polymers (e.g., 3,4-polyethylenedioxythiophene (PEDOT) or polyaniline). The electrolyte layer is typically designed as a film of an organic or inorganic, highly ionically conductive, electrical blocking material, such as one based on lithium phosphate nitride. The ion storage layer is either permanently transparent (pure ion storage) or has the opposite electrochromic behavior to the electrochromic layer. An example of a pure ion storage layer is a layer containing mixed oxides of titanium and cerium; an example of an anodic electrochromic ion storage layer is a layer containing iridium oxide or nickel oxide.

[0051] The voltage source for the functional element is preferably a control unit suitable for operating the functional element. The control unit is suitable for applying a voltage between the first planar electrode, on the one hand, and the second planar electrode or the electrode segments of the second planar electrode (respectively), on the other hand. Depending on the type of functional element, the voltage provided by the control unit can be a DC voltage (e.g., in the case of electrochromic functional elements) or an AC voltage (e.g., in the case of SPD functional elements, PDLC functional elements, or other functional elements based on liquid crystal technology). If the functional element operates with an AC voltage while the primary voltage source provides a DC voltage (e.g., as is common in vehicle electrical systems), the control unit can include an inverter. If the functional element operates with a DC voltage while the primary voltage source provides an AC voltage, the control unit can have a rectifier.

[0052] A control unit is provided and is suitable for controlling the optical properties of the functional element. The control unit is electrically and conductively connected to the planar electrodes of the functional element on the one hand and to a primary voltage source on the other hand. The control unit has the electrical and / or electronic components required to apply the required voltage to the planar electrodes depending on the switching state. The switching state may be predefined by a user (e.g., by operating a switch, a button, or a rotary or sliding controller), determined by a sensor, and / or sent from the vehicle's central control unit via a digital interface (typically a LIN bus or CAN bus if the composite pane is a vehicle window pane). The switch, button, rotary or sliding controller may be integrated, for example, into the vehicle's dashboard if the composite pane is a vehicle window pane. However, a touch sensor, e.g., a capacitive or resistive sensor, may also be integrated directly into the composite pane. Alternatively, the functional element may be controlled by a non-contact method, for example, by gesture recognition, or depending on the state of the pupil or eyelid determined by a camera and appropriate evaluation electronics. The control unit may include, for example, an electronic processor, a voltage converter, transistors, and other components.

[0053] The control unit may be mounted on the interior surface of the inner pane away from the intermediate layer, or, for example, if the composite pane is a vehicle window pane, may be integrated into the vehicle's electrical system or mounted to the vehicle body.

[0054] Composite panes are typically provided in window openings (e.g., window openings in vehicles, buildings, or rooms) to separate the interior space from the exterior environment. In the context of the present invention, the term "inner pane" is understood to mean the pane facing the interior space. By outer pane is meant the pane facing the exterior environment. The outer pane and the inner pane each have an outer surface and an inner surface, and a peripheral edge surface extending therebetween. By outer surface, in the sense of the present invention, is meant the major surface intended to face the exterior environment when installed. By inner surface, in the sense of the present invention, is meant the major surface intended to face the interior when installed. The inner surface of the outer pane and the outer surface of the inner pane face each other and are bonded to each other by a thermoplastic intermediate layer.

[0055] The outer and inner panes are preferably made of or formed from glass, particularly preferably soda-lime glass, as is customary for window glass. However, the panes can also be made from other types of glass, such as quartz glass, borosilicate glass, or aluminosilicate glass, or from hard, transparent plastics, such as polycarbonate or polymethylmethacrylate. The panes can be colorless or can be colored or tinted.

[0056] The thickness of the outer and inner panes may vary widely and thus be adapted to the requirements of each individual case. The thickness of the outer and inner panes is preferably 0.5 mm to 5 mm, particularly preferably 1 mm to 3 mm. The outer and inner panes may be flat, cylindrical, or spherically curved. Spherically curved composite panes are common, especially for vehicle glazing, while flat composite panes are common for building glazing.

[0057] The outer pane, inner pane, and / or intermediate layer may have any known suitable coating, such as an anti-reflective coating, a non-stick coating, a scratch-resistant coating, a photocatalytic coating, a UV absorbing or reflective coating, or an IR absorbing or reflective coating, such as a solar protection coating or a low-E coating.

[0058] The composite pane may be provided with an opaque cover print, particularly at least in the peripheral edge region, as is common practice in the vehicle field, especially for windshields, rear windows, and roof panes. The cover print is typically made of enamel containing glass frit and pigment, especially black pigment. The printing ink is typically applied by screen printing and then baked. Such a cover print is applied to at least one pane surface, preferably the inner surface of the outer pane and / or the inner pane. The cover print preferably surrounds a central see-through region in a frame-like manner. The cover print creates an opaque masking region on the composite pane. The contact and connection regions of the functional element are preferably arranged within this masking region.

[0059] A thermoplastic interlayer serves to connect the two panes, as is common practice in composite panes. A thermoplastic film is typically used, forming the interlayer. In a preferred embodiment, a functional element is disposed between two thermoplastic layers. Here, the interlayer is formed from at least a first thermoplastic layer and a second thermoplastic layer, with the functional element disposed therebetween. The functional element is then connected to the outer pane through a region of the first thermoplastic layer and to the inner pane through a region of the second thermoplastic layer. The thermoplastic layers preferably protrude circumferentially beyond the functional element. If the thermoplastic layers are in direct contact with each other and are not separated from each other by a functional element, they will fuse during lamination, such that the original layers may become indistinguishable and instead a uniform interlayer is present.

[0060] The thermoplastic layer can be formed, for example, by a single thermoplastic film. The thermoplastic layer can be formed from multiple sections of different thermoplastic films, the side edges of which are joined together.

[0061] In a preferred embodiment, the functional element, or more precisely, the side edges of the functional element, are circumferentially surrounded by a third thermoplastic layer. The third thermoplastic layer is frame-shaped and has a recess into which the functional element is inserted. The third thermoplastic layer can be formed by a thermoplastic film into which the recesses are cut. Alternatively, the third thermoplastic layer can be composed of multiple film sections arranged around the functional element. In this case, the intermediate layer is formed from a total of at least three thermoplastic layers arranged flatly one on top of the other, with the central layer having the recess in which the functional element is arranged. During production, the third thermoplastic layer is arranged between the first and second thermoplastic layers, with the side edges of all thermoplastic layers preferably coinciding. The third thermoplastic layer preferably has a thickness approximately equal to that of the functional element. This compensates for the local thickness difference introduced by the locally limited functional element, thereby avoiding glass breakage during lamination and resulting in an improved visual appearance.

[0062] Alternatively, however, the functional element may be located directly on the surface of the outer or inner pane facing the intermediate layer. Preferably, the lateral edges of the functional element are completely surrounded by the intermediate layer, so that the functional element does not extend to the lateral edges of the composite pane and is therefore not in contact with the surrounding atmosphere. In this case too, a frame-shaped thermoplastic layer may be used around the functional element.

[0063] The thermoplastic layers of the intermediate layer are preferably made of the same material, but in principle may be made of different materials. The layer or film of the intermediate layer is preferably made based on polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), or polyurethane (PU). This means that the layer or film contains mainly (more than 50% by weight) of the above material, and may optionally contain further components, such as plasticizers, stabilizers, UV or IR absorbers, etc. The thickness of each thermoplastic layer is preferably 0.2 mm to 2 mm, particularly preferably 0.3 mm to 1 mm. For example, films with a standard thickness of 0.38 mm or 0.76 mm can be used.

[0064] Composite panes can be made by stacking individual layers in the intended order to form a stack of layers, and then laminating the outer and inner panes together via an intermediate layer. Known methods can be used, such as autoclave, vacuum bag, vacuum ring, calendar, vacuum laminator, or combinations thereof. The outer and inner panes can be joined, typically under the influence of heat, vacuum, and / or pressure.

[0065] The layer stack preferably comprises, in a particular order: - outer pane, - a first thermoplastic film forming the first thermoplastic layer of the intermediate layer; - a functional element, preferably surrounded by a frame-shaped third thermoplastic film having a recess, - a second thermoplastic film forming the second thermoplastic layer of the intermediate layer; - Inner pane.

[0066] When the layers are stacked, the functional elements are provided with the necessary electrical connections, with electrical conductors extending beyond the side edges of the layer stack, after which an external voltage source can be provided.

[0067] In an advantageous embodiment, the functional elements are provided with current collecting rails, which are connected to planar electrodes, optionally via electrical contact layers. Electrical conductors are provided on the thermoplastic film and are appropriately positioned so that they come into contact with the current collecting rails without further measures when the layer stack is created. The electrical conductors preferably comprise ribbon conductors arranged laterally on the functional elements, electrical contact elements for direct connection to the current collecting rails, and electrical lines (e.g., wires or cables) between each contact element and the conductor tracks of the ribbon conductors. The electrical conductors are each attached to a thermoplastic film, to which the planar electrodes, which are in contact with the conductors, are exposed. For example, if a first carrier film with a first planar electrode faces the first thermoplastic film, the first planar electrode is exposed to the second thermoplastic film in the first contact area: in the first contact area, only the first carrier film and the first planar electrode are present, with the first planar electrode facing the second thermoplastic film.

[0068] The present invention also includes the use of a composite pane according to the present invention in a building or in land, air or water transport, for example as a vehicle window pane, as a window pane for a building or room (interior of a building), or as a component of furniture, electrical equipment or furnishings. The composite pane is preferably a window pane for a vehicle, in particular an automobile. The glazing unit may be used, for example, as a windshield, roof pane, rear wall pane or side pane, preferably as a windshield or roof pane.

[0069] In a particularly preferred embodiment, the composite pane is a vehicle windshield, where the functional element is preferably used as an electrically controlled sunscreen located in the upper region of the windshield, while the majority of the windshield is free of the functional element. Multiple switching regions may be provided, preferably arranged substantially parallel to the upper edge of the windshield at increasing distances from the upper edge. As a result of the independently switchable regions, the user may determine the extent of the region adjacent the upper edge that is shaded or provided with highly scattered light depending on the position of the sun, thereby avoiding sun glare.

[0070] In yet another preferred embodiment, the composite pane is a vehicle roof pane. The functional element is preferably disposed over the entire see-through region of the composite pane. In a typical embodiment, this see-through region includes the entire composite pane except for a peripheral edge region, which is provided with opaque cover printing on at least one surface of the pane. The functional element extends over the entire see-through region, with its side edges located within the opaque cover printing region and therefore invisible to an observer. The transition regions are preferably disposed substantially parallel to the front edge of the roof pane and at increasing distances from the front edge. The independently switchable transition regions allow a user to define which regions of the roof pane should be transparent and which regions should be shaded or provided with highly scattered light, for example, depending on the position of the sun to prevent overheating inside the vehicle. Each vehicle occupant, i.e., the driver, front passenger, left rear passenger, and right rear passenger, may also be assigned a transition region located above them.

[0071] The invention will now be explained in more detail with reference to the drawings and exemplary embodiments. The drawings are schematic representations and are not to scale. The drawings are not intended to limit the invention in any way. In the drawings: [Brief explanation of the drawings]

[0072] [Figure 1] FIG. 1 is a cross-sectional view of an embodiment of a composite pane according to the present invention.

[0073] [Figure 2] FIG. 2 is a cross-sectional view of the functional elements of the composite pane from FIG.

[0074] [Figure 3] FIG. 3 is a plan view of the functional elements from FIG.

[0075] [Figure 4] FIG. 4 is a plan view of the functional elements of a further embodiment of a composite pane according to the invention.

[0076] [Figure 5] FIG. 5 is a plan view of the functional elements of a further embodiment of a composite pane according to the invention.

[0077] [Figure 6] FIG. 6 is a plan view of the functional elements of a typical conventional composite pane. DETAILED DESCRIPTION OF THE INVENTION

[0078] FIG. 1 shows a cross-sectional view of a composite pane design according to the present invention with electrically controllable optical properties. The composite pane may be used, for example, as a roof pane for a passenger vehicle, and its light transmission may be electrically controlled. The composite pane comprises an outer pane 1 and an inner pane 2, which are connected to each other via an interlayer 3. The outer pane 1 and the inner pane 2 are made of soda-lime glass, which may optionally be tinted. The outer pane 1 may have a thickness of, for example, 2.1 mm, and the inner pane 2 may have a thickness of 1.6 mm.

[0079] The intermediate layer 3 comprises three thermoplastic layers 3a, 3b, and 3c, each formed by a PVB thermoplastic film having a thickness of 0.38 mm. The first thermoplastic layer 3a is connected to the outer pane 1, and the second thermoplastic layer 3b is connected to the inner pane 2. The third thermoplastic layer 3c in between has a cutout into which the functional element 10 with electrically controllable optical properties is inserted so that it fits essentially exactly, i.e., is nearly flush on all sides. In this way, the third thermoplastic layer 3c forms a sort of base or frame for the functional element 10, which is approximately 0.4 mm thick, and is encapsulated and protected by the thermoplastic material.

[0080] The composite pane has a peripheral edge region provided with an opaque cover print 4. Such cover print 4 is typically made of black enamel. It is transferred by a screen printing method as a printing ink containing black pigment and glass frit and baked into the glass surface. The cover print 4 is applied, for example, to the inner surface of the outer pane 1 and to the inner surface of the inner pane 2. The side edges of the functional element 10 are covered by this cover print 4.

[0081] For clarity, FIG. 2 shows a cross-sectional view of the functional element 10 of FIG. 1 alone. The functional element 10 is, for example, a PDLC multilayer film that can be switched from a colorless, transparent state to an opaque (colored), non-transparent (diffusive) state. The functional element 10 comprises an active layer 11 between a first planar electrode 14 and a second planar electrode 15. The first planar electrode 14 is applied to a first carrier film 12, and the second planar electrode 15 is applied to a second carrier film 13. The active layer 11 comprises a polymer matrix in which liquid crystals are dispersed, which orients in response to a voltage applied to the planar electrodes 14, 15, thereby controlling the optical properties. The carrier films 12, 13 are made of PET and have a thickness of, for example, 0.125 mm. Each of the carrier films 12, 13 is provided with an ITO coating facing the active layer 11 and having a thickness of approximately 100 nm, which forms the planar electrodes 14, 15.

[0082] The functional element 10 has a first contact area where the first planar electrode 14 is exposed, thereby connecting it to a voltage source. In the first contact area, the second carrier film 13, the second planar electrode 15 and the active layer 11 are removed. In the first contact area, a current collecting rail 21 is arranged on the first planar electrode 14 via an electrical contact layer 23.

[0083] The functional element 10 has a second contact area where the second planar electrode 15 is exposed, thereby connecting it to a voltage source. In the second contact area, the first carrier film 12, the first planar electrode 14 and the active layer 11 are removed. In the second contact area, a current collecting rail 22 is arranged on the second planar electrode 15 via an electrical contact layer 23.

[0084] Figure 3 shows a plan view of the functional element 10 of figure 2. The second carrier film 13 faces the viewer. The functional element is rectangular in shape with four straight side portions and four corners.

[0085] The first contact area extends along the left side portion and is immediately adjacent to the side edge of the functional element 10, where the second carrier film 13, the second planar electrode 15 and the active layer 11 have been removed, thereby revealing the first planar electrode 14 (shown in dotted lines) exposed on the first carrier layer 12.

[0086] The second contact area extends along the right side portion and is immediately adjacent to the side edge of the functional element 10, where the first carrier film 12, the first planar electrode 14 and the active layer 11 have been removed. The second planar electrode 15 is not visible here, since it is covered on top with the second carrier film 13. The left boundary (cut line) of the second contact area is indicated by a thin dashed line.

[0087] In the second contact area, a current collecting rail 22 is arranged on the second planar electrode 15. It is shown in dashed outline and in grey because it is located behind the second carrier film 13 and is therefore only visible when looking through. In the first contact area, a current collecting rail 21 is arranged on the first planar electrode 14.

[0088] Adjacent to the lower side edge, a connection region extends from the first contact region to the opposite right side portion of the functional element 10. In the connection region, as in the first contact region, the second carrier film 13, the second planar electrode 15 and the active layer 11 have been removed, thus exposing the first planar electrode 14.

[0089] A part of the current collecting rail 21 of the first planar electrode 14 is arranged in the first contact area, and a further part is arranged in a connection area starting from the first contact area to the opposite right side part of the functional element 10. This has the advantage that both current collecting rails 21, 22 can be electrically connected to the same side of the functional element 10, i.e. the right side part.

[0090] The dashed outline of the second contact area corresponds to the cutting line for removing the first carrier film 12. In the plan view shown, it is located below the second contact area relative to the lateral edge of the functional element, in the right side portion before reaching the connection area. As a result, an intermediate area is located between the second contact area and the connection area, in which the first carrier film 12, the first planar electrode 14 and the active layer 11 are not removed.

[0091] For electrical connection to an external voltage source, the composite pane is provided with ribbon conductors 27, which are arranged laterally of the functional element 10 and spaced apart from the right side portion. The ribbon conductors 27 extend beyond the side edges of the composite pane. T-shaped electrical contact elements 25 are arranged on the current collecting rails 22 of the second planar electrode 15 and are directly connected to the ribbon conductors 27. Most of the contact elements 25 are again shown with dashed outlines and in gray because they are located behind the second carrier film 13 and the current collecting rails 22. Strip-shaped electrical contact elements 24 are arranged on the current collecting rails 21 of the first planar electrode 14 in the connection area and are directly connected to the ribbon conductors 27. Each contact element 24, 25 is connected to one of two conductor tracks of the ribbon conductors 27, which are not shown for simplicity.

[0092] The current collecting rails have a width of, for example, 5 mm. They are made of, for example, copper foil having a thickness of 50 μm. The electrical contact layer 23 consists, for example, of silver paste having a thickness of 50 μm. The electrical contact elements 24, 25 are also made, for example, of copper foil having a thickness of 50 μm.

[0093] In the intermediate region between the second contact region and the connection region, part of the second planar electrode 15 is electrically isolated from the rest of the second planar electrode 15 by an isolation line 16. The isolation line 16 divides the second planar electrode 15 into an active region, which functions as the actual planar electrode, and an area isolated therefrom and adjacent to the connection region. This reduces the risk of short circuits, since the part of the second planar electrode 15 adjacent to the connection region could easily come into contact with the first planar electrode 14 or its current collecting rail 21. The isolation line 16 is introduced into the second planar electrode 15 by laser irradiation and has a line width of, for example, 100 μm.

[0094] Figure 4 shows a plan view of a functional element 10 in a further embodiment of a composite pane according to the invention. Functional element 10 is essentially configured similarly to the embodiment shown in Figures 2 and 3. In contrast, functional element 10 has three independent switching regions whose switching states can be set independently of one another. The switching regions allow the vehicle operator (e.g., depending on the position of the sun) to select a diffusive state for only one region of the composite pane, rather than the entire composite pane, while leaving the other regions transparent.

[0095] For this purpose, the second planar electrode 15 is divided into three electrode segments 15.1, 15.2, and 15.3 by two interruption lines 15'. The interruption lines 15' are introduced into the planar electrode 15 by laser irradiation and have a line width of, for example, 100 μm. Each electrode segment 15.1, 15.2, and 15.3 is connected independently to a voltage source. A control unit is adapted to apply an electric voltage independently between each of the electrode segments 15.1, 15.2, and 15.3 of the second planar electrode 15 on the one hand and the first planar electrode 14 on the other hand, thereby applying the required voltage to the portion of the active layer 11 located between them and thereby achieving the desired switching state.

[0096] Each electrode segment 15.1, 15.2, 15.3 is provided in the second contact region with a current collecting rail 22.1, 22.2, 22.3, which is further provided with an electrical contact element 25.1, 25.2, 25.3. In contrast to the designs of Figures 2 and 3, the contact elements 24, 25.1, 25.2, 25.3 are not directly connected to the ribbon conductor 27, but rather via electrical wiring 26 connected thereto. The ribbon conductor 27 has at least four conductor tracks, where each current collecting rail 21, 22.1, 22.2, 22.3 is connected to a separate conductor track. The electrical wires 26 are formed, for example, as tungsten wires with a diameter of 150 µm.

[0097] A further difference with the designs of Figures 2 and 3 is the shape of the dashed outline of the second contact area, which does not form a right angle below the second contact area and is therefore led to the right side portion, but instead is curved, which is technically easier to implement.

[0098] In this embodiment, too, a portion of the second planar electrode 15 is electrically isolated from the rest of the second planar electrode 15 by a blocking line 16 in the intermediate region between the second contact region and the connection region. The blocking line 16 divides the second planar electrode 15 into an active region, which functions as the actual planar electrode and is divided into three independent segments 15.1, 15.2, and 15.3, and an area adjacent to the connection region that is isolated from the active region. This reduces the risk of short circuits, since the portion of the second planar electrode 15 adjacent to the connection region could easily come into contact with the first planar electrode 14 or its current collecting rail 21. The blocking line 16 is introduced into the second planar electrode 15 by laser irradiation and has a line width of, for example, 100 μm. Since the functional element 10 has already been laser-treated to create the blocking line 15′, creating the blocking line 16 requires only minor additional costs.

[0099] Figure 5 shows a plan view of a functional element 10 in a further embodiment of a composite pane according to the invention. The functional element 10 is essentially constructed similarly to the embodiment shown in Figures 2 and 3. In contrast, the connection regions are arranged in a central region of the functional element 10, rather than adjacent to the lower side portions.

[0100] Because the second carrier film 13, the second planar electrode 15, and the active layer 11 are removed in the connection region, the connection region divides the functional element into two switching regions whose optical properties can be electrically controlled. The carrier films 12, 13, the planar electrodes 14, 15, and the active layer 11 are completely present in the switching region. The second planar electrode 15 is divided by the connection region into two electrode segments 15.1, 15.2. The second contact region is also divided into two parts. Each electrode segment 15.1, 15.2 is provided with a current collecting rail 22.1, 22.2 in the second contact region, which is further connected to a ribbon conductor 27 via electrical contact elements 25.1, 25.2 and electrical lines 26 connected to them. The ribbon conductor 27 has at least three conductor tracks, and each current collecting rail 21, 22.1, 22.2 is connected to a separate conductor track.

[0101] In the plan view shown, between each portion of the second contact area and the connection area, an intermediate area is again arranged, in which the first carrier film 12, the first planar electrode 14 and the active layer 11 have not been removed. Within each intermediate area, an interruption line 16 is arranged, which divides the respective portion of the second planar electrode 15 into an active part and a part that is interrupted therefrom and adjacent to the connection area, which serves to avoid short circuits within the connection area.

[0102] For comparison, Figure 6 shows a plan view of a functional element 10 in a conventional design of a typical composite pane. Similar to Figure 4, the functional element 10 is divided into three independent switching areas.

[0103] Electrical connections are made via electrical wires 26 extending from each current collecting rail beyond the side edges of the composite pane. The connection of current collecting rail 21 to first planar electrode 14 is made on the left side of functional element 10, and the connection of current collecting rails 22.1, 22.2, 22.3 is made on the right side of functional element 10. However, since wires 26 are intended to exit the composite pane at approximately the same point, typically combined with a common connector for connection to a voltage source, wires 26 of current collecting rail 21 are routed around functional element 10. Therefore, relatively longer cables 26 are required than in embodiments of the present invention, and their installation takes relatively more time. [Explanation of symbols]

[0104] (1) Outer pane (2) Inner pane (3) Thermoplastic intermediate layer (3a) First layer of middle layer 3 (3b) Second layer of middle layer 3 (3c) Third layer of middle layer 3 (4) Cover printing (10) Electrically controllable functional elements (11) an active layer of the layer sequence of the functional element 4 having electrically controllable optical properties; (12) Functional element 4 first carrier film (13) Second carrier film of functional element 4 (14) First planar electrode of functional element 4 (15) Second planar electrode of functional element 4 (15.1, 15.2, 15.3) Electrode segments of the second planar electrode 15 (15') Interruption line between two electrode segments 15.1, 15.2, and 15.3 (16) Breaking wire (21) Collector rail of first flat electrode 14 (22) Current collecting rail of second flat electrode 15 (22.1, 22.2, 22.3) First, second, and third current collecting rails of the second planar electrode 15 (23) Electrical contact layer (24) Electrical contact element of current collecting rail 21 (25) Electrical contact element of current collecting rail 22 (25.1, 25.2, 25.3) Electrical contact elements of the first, second and third current collecting rails of the second planar electrode 15 (26) Electrical wires (27) Ribbon conductor X-X' cutting line

Claims

1. 1. A composite pane having electrically controllable optical properties, comprising: an outer pane (1) and an inner pane (2) connected to each other via a thermoplastic intermediate layer (3); - electrically controllable functional elements (10) embedded in said intermediate layer (3), which are, in a specific order: a first carrier film (12), - first planar electrode (14), an active layer (11) or layer sequence with electrically controllable optical properties, a second planar electrode (15), and - second carrier film (13) a functional element (10) having and where: in the first contact area, the second carrier film (13), the second planar electrode (15) and the active layer (11) or layer sequence are removed and the first planar electrode (14) is electrically conductively connected to a current collecting rail (21); in a second contact area, the first carrier film (12), the first planar electrode (14) and the active layer (11) or layer sequence are removed and the second planar electrode (15) is electrically conductively connected to at least one current collecting rail (21; 22.1, 22.2, 22.3), wherein the first contact area and the second contact area are arranged on opposite sides of the functional element (10); wherein the current collecting rails (21) of the first planar electrode (14) extend in a connection area from the first contact area to the opposite side of the functional element (10), and wherein the second carrier film (13), the second planar electrode (15) and the active layer (11) or layer sequence are removed in the connection area, the composite pane is characterized in that, between the second contact area and the connection area, there is an intermediate area in which the first carrier film (12), the first planar electrode (14) and the active layer (11) or layer sequence are not removed, and in which, in the intermediate area, a part of the second planar electrode (15) adjacent to the connection area is electrically isolated from the rest of the second planar electrode (15) by an isolation line (16). Compound pane.

2. 2. A composite pane according to claim 1, wherein the current collecting rail (21) of the first planar electrode (14) and the at least one current collecting rail (21; 22.1, 22.2, 22.3) of the second planar electrode (15) are connected to a voltage source via electrical conductors (24, 25, 26, 27), the electrical conductors (24, 25, 26, 27) being connected to the current collecting rail (21) of the first planar electrode (14) and the at least one current collecting rail (21; 22.1, 22.2, 22.3) of the second planar electrode (15) on the same side of the functional element (10).

3. 3. A composite pane according to claim 1 or 2, wherein the second planar electrode (15) is divided by at least one interruption line (15') into at least two separate electrode segments (15.1, 15.2, 15.3), each electrode segment (15.1, 15.2, 15.3) electrically conductively connected to a respective current collecting rail (22.1, 22.2, 22.3).

4. A composite pane according to any one of claims 1 to 3, wherein the or each interruption line (16) (15', 16) has a width of between 5 μm and 500 μm.

5. Composite pane according to any one of claims 1 to 4, wherein the functional element (10) has an at least approximately quadrangular, in particular at least approximately rectangular, shape.

6. Composite pane according to any one of claims 1 to 5, wherein the functional element (10) is a functional element based on liquid crystal technology, in particular a PDLC functional element, an SPD functional element or an electrochromic functional element.

7. Composite pane according to any one of claims 1 to 6, wherein the current collecting rails (21, 22, 22.1, 22.2, 22.3) are made from an electrically conducting foil, in particular a copper foil.

8. Composite pane according to any one of the preceding claims, wherein the planar electrodes (14, 15) are made on the basis of indium tin oxide (ITO) or silver.

9. 9. A composite pane according to any one of claims 1 to 8, comprising ribbon conductors (27) arranged laterally of the functional element (10) and extending beyond the lateral edges of the composite pane, wherein the current collecting rail (21) of the first planar electrode (14) and the at least one current collecting rail (22; 22.1, 22.2, 22.3) of the second planar electrode (15) are electrically conductively connected to the ribbon conductors (27).

10. 10. A composite pane according to claim 9, wherein the current collecting rails (21, 22, 22.1, 22.2, 22.3) are provided with respective electrical contact elements (24, 25, 25.1, 25.2, 25.3), which are made from an electrically conductive foil, in particular a copper foil, and which are connected to the ribbon conductor (27) either directly or via respective electrical wires (26), which are made as metal wires, electrical cables or printed lines.

11. Composite pane according to any one of claims 1 to 10, wherein the carrier film (12, 13) is made on the basis of polyethylene terephthalate (PET) and preferably has a thickness of 10 μm to 200 μm.

12. Composite pane according to any one of claims 1 to 11, wherein said functional element (10) is arranged between two thermoplastic layers (3a, 3b), said thermoplastic layers (3a, 3b) being preferably based on polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) or polyurethane (PU) and preferably having a thickness of between 0.2 mm and 2 mm.

13. A composite pane according to any one of claims 1 to 12, wherein the outer pane (1) and the inner pane (2) are made of soda lime glass, preferably having a thickness of 0.5 mm to 5 mm.

14. 14. Use of a composite pane according to any one of claims 1 to 13 as a window pane, in particular as a windshield or roof panel, in a vehicle, as a window pane in a building or interior space, or as a component of furniture, electrical equipment or furnishings.

Images