Functional device having electrically controllable optical properties

Abstract

In a functional element (5) having electrically controllable optical properties having a plurality of side edges (4.1, 4.2, 4.3, 4.4), comprising a first carrier film (14) having at least a first planar electrode (12), a second carrier film (15) having a second planar electrode (13), and an active layer (11) arranged flatly between the first planar electrode (12) and the second planar electrode (13). - The first busbar (18) and the second busbar (19) are arranged on at least one first side edge (4.1), and - The first carrier film (14) has at least one first concave portion (10.1), and the second carrier film (15) has at least one second concave portion (10.2). Here - The first busbar (18) is arranged on the surface of the second carrier film (15) facing away from the second planar electrode (13), passes through at least one second concave area (10.2), and is electrically conductively in contact with the first planar electrode (12). - The second busbar (19) is arranged on the surface of the first carrier film (14) facing away from the first planar electrode (12), passes through at least one first concave area (10.1), and is electrically conductively in contact with the second planar electrode (13). - At least one first busbar (18) is divided into at least one first section (18.1) and at least one second section (18.2), which can be controlled independently of each other and / or at least one second busbar (19) is divided into at least one first section (19.1) and at least one second section (19.2), which can be controlled independently of each other, and - The first concave portion (10.1) and the second concave portion (10.2) are functional elements (5) arranged alternately with respect to each other.

Description

Technology Field

[0001] The present invention relates to a functional element having electrically controllable optical properties, a method for switching the functional element in stages, and a composite plate glass comprising such functional element. Background Technology

[0002] Conventional automobiles are equipped with mechanical sunshades to prevent glare for the driver or additional passengers. These devices are mounted on the vehicle roof in a hinged or movable manner and can be folded down or pulled out as needed to prevent or minimize glare for the driver or passengers.

[0003] Windshields and roof panels integrated with sunshades in the form of functional elements possessing electrically controllable optical properties, particularly electrically controllable transmission or scattering behavior, are also known. Consequently, drivers can control the transmission behavior of the glazing itself against solar radiation, potentially eliminating the need for conventional mechanical sunshades. This can reduce vehicle weight and free up space in the roof area. Furthermore, electrically controlling the sunshades offers greater convenience for the driver. Particularly when a large-area panoramic glass panel is present in the roof area, there is a need to variably control the transmittance of the glass panel. Depending on the position of the sun, it may be necessary to obscure only a portion of the glass panel or switch the entire surface to opaque mode to ensure the privacy of a parked vehicle.

[0004] Electrically switchable functional devices that can be considered for implementing controllable shading include electrochromic functional devices, PDLC (polymer dispersed liquid crystal) functional devices, SPD (suspended particle devices) functional devices, and electroluminescent functional devices. The operating principles of these functional devices are known to those skilled in the art. The aforementioned functional devices generally comprise two carrier films, each having a planar electrode arranged thereon, and an active layer is introduced between the carrier films directly adjacent to the planar electrode. The optical properties of the active layer vary depending on the voltage applied to the planar electrode. To gradually or partially change the optical properties, a voltage is applied locally or partially to the planar electrode. Thus, the electrical contact can be adjusted accordingly.

[0005] Electrical contact of an electrically controllable functional element is generally established through a conductor bar (also called a "bus bar") that is applied to a planar electrode located at the edge region of the functional element and electrically contacts the planar electrode. For example, by connecting the bus bar to an external voltage source through a planar conductor attached to the bus bar, voltage is applied to the planar electrode, and the active layer of the functional element is switched. As the area of ​​the individually electrically controllable region becomes smaller, the parts related to electrical contact become more complex and smaller.

[0006] EP 2416385 A1 relates to a multilayer back contact film and a method for connecting solar cells through the same.

[0007] EP 1840449 A1 describes a lighting panel comprising a glass substrate, an electrically conductive coating, and a plurality of LEDs, wherein the LEDs are electrically contacted through conductor tracks of the electrically conductive coating and two busbars are arranged on the same edge of the lighting panel.

[0008] WO 2020 / 083563 A1 and WO 2020 / 083562 A1 disclose a composite plate glass having an electrically controllable functional element that can be switched on a segment-by-segment basis, wherein a first group of busbars comprises a first group of busbars electrically in contact with a segment introduced into a first planar electrode and at least one second busbar electrically in contact with a second planar electrode. The problem to be solved

[0009] The present invention aims to provide a switchable functional element having electrically controllable optical characteristics, improved to enable stepwise switching of electrical control. means of solving the problem

[0010] The problem to be solved by the present invention is solved by a functional element having electrically controllable optical properties according to independent claim 1. Preferred embodiments are explicitly described in the dependent claims.

[0011] A functional element according to the present invention comprises an active layer between a first planar electrode and a second planar electrode. The active layer has controllable optical properties that can be controlled by a voltage applied to the planar electrode. The planar electrode is applied to a carrier film. The planar electrode, the active layer, and the carrier film are generally arranged substantially parallel to each other. The planar electrode is electrically conductively connected to a busbar to which the functional element can be connected to an external voltage source. The active layer is arranged flatly between the first planar electrode and the second planar electrode. The functional element comprises a plurality of side edges, and the first busbar and the second busbar are arranged on at least one first side edge. The first busbar is electrically conductively in contact with the first planar electrode, and the second busbar is electrically conductively in contact with the second planar electrode. The first carrier film comprises at least one first recess in which the material of the first carrier film is removed, with the first planar electrode located on top. A second busbar is attached to the surface of a first carrier film in a direction away from the active layer and the first planar electrode. The second busbar passes through a first recess and is electrically in contact with the second planar electrode in this region. In this case, no active layer exists in the first recess region, and the second busbar is electrically in direct contact with the second planar electrode. The first busbar extends over the surface of a second carrier film in a direction away from the active layer and the second planar electrode. The second carrier film includes at least one second recess from which the material of the second carrier film and the second planar electrode located thereon has been removed. The first busbar is coupled to the first planar electrode through the second carrier film in the second recess region and is electrically in contact with it. In this case, no active layer exists in the second recess region, and the first busbar is electrically in direct contact with the first planar electrode in this region. At least one of the busbars is divided into at least one first section and at least one second section.Accordingly, the first busbar is divided into at least one first section and at least one second section, and / or the second busbar is divided into at least one first section and at least one second section. The sections of the first busbar can be controlled independently of each other. The same applies to the sections of the second busbar.

[0012] It is desirable that adjacent sections of the busbar be separated from each other by a separator, and that electrical conductivity of the insulator exists in the region of the separator, and that no current flows between adjacent sections of the busbar. In this way, the region of the functional element can be targeted and controlled. The busbar is first attached along at least one side edge and can then be divided into at least two sections, so it is not required to apply the sections only once.

[0013] The functional element according to the present invention enables simple electrical contact of planar electrodes in edge regions. In order to make electrical contact with planar electrodes located far from each busbar, the busbar is applied to the surface of a carrier film located in a direction away from the planar electrode in each case and passes through the carrier film locally closest in the concave region. In this way, the first busbar and the second busbar can be applied together to the first side edge. This reduces the number of side edges that need to be contacted.

[0014] When one or two busbars are divided into electrically separated sections, the active layer can be selectively switched section by section, wherein the selectively switchable active layer region is located within the planar electrode region to which voltage is applied through the busbar. To control individual regions of the functional element by targeting them, the opposite poles of the voltage source are connected to each section of the busbars of the first planar electrode and the second planar electrode according to the desired active layer connection diagram. The first pole of the voltage source is connected to the section of the second busbar, and the opposite pole of the voltage source is connected to the section of the first busbar, thereby coming into contact with the region of the first planar electrode to be controlled. Therefore, the potential difference between the planar electrodes exists only in the region of the functional element where the first planar electrode corresponding to the region of the functional element is connected to the voltage source. Consequently, the active layer of the functional element is also switched only in these regions. Targeted control is performed, for example, through an external control unit, by targeting the sections of the first planar electrode to which voltage is to be applied.

[0015] The first concave portion and the second concave portion are arranged alternately with respect to one another. Thus, there exists at least one first concave portion and at least two second concave portions, or at least two first concave portions and at least one second concave portion, which are arranged alternately along the first side edge. Preferably, there exist at least two first concave portions and at least two second concave portions, which are arranged alternately with respect to one another along the first side edge. Alternately arranging the concave portions enables target control of all surface areas of the functional element, and as the number of first and second concave portions increases, the precision of the target control is improved.

[0016] The functional element has multiple side edges, particularly preferably four side edges. However, the functional element may include more than four side edges. In each case, at least two side edges of the functional element are essentially paired and positioned facing each other. In one embodiment having four side edges, there are two pairs of two side edges facing each other. Opposing side edges of the functional element may or may not be parallel to each other. Side edges do not need to be straight and are often curved. The lengths of opposing edges may differ. For example, the functional element may have a trapezoidal contour. In a preferred embodiment, the functional element has multiple side edges, for example, four side edges.

[0017] In a preferred embodiment of the functional element, at least one additional first busbar and / or second busbar is arranged on at least a second side edge. The at least one additional busbar creates a more uniform voltage distribution, thereby improving the switching operation of the functional element. For a uniform voltage distribution, the busbar is arranged particularly on the opposing edge of the functional element. Particularly preferably, the first busbar and the second busbar are arranged on at least one second side edge so that the busbar and the associated planar electrode are in contact through the first recess and the second recess. The first and second recesses are attached along the second side edge similar to the possible arrangement described on the first side edge, and the arrangement on the first side edge may differ from the arrangement on the second side edge within the functional element.

[0018] The present invention enables the attachment of a first busbar and a second busbar together to the side edges of a functional element. Consequently, if necessary, the other side edge of the functional element may remain without a busbar. This is advantageous, for example, when the functional element does not extend across the entire surface of the glazing and the edge of the functional element is located in a visually transparent glazing area. For an attractive appearance, the second busbar is omitted from this side edge.

[0019] The functional element preferably has a first busbar and a second busbar along a first side edge, a second side edge, a third side edge, and a fourth side edge. This allows for switching behavior to be as uniform as possible across all regions of the functional element when switching simultaneously. On the other hand, switching the functional element in stages makes it possible to control individual regions very precisely.

[0020] In one possible embodiment, the first planar electrode and / or the second planar electrode comprises at least one separating line that divides the functional elements into regions, also called segments, which can be switched independently of each other. The separating line, also called an isolation line, electrically separates individual parts of the planar electrode from each other. Within the meaning of the invention, the separating line should be understood as a linear region within the planar electrode that is not electrically conductive and extends over the entire thickness of the planar electrode. It is ensured that no current flows through the separating line between individual segments of the planar electrode except through a controlled portion of the coating. The segment width of the planar electrode is determined by the distance between one or more separating lines that limit the width of the segment. Here, the width of the segment is measured along the direction in which the shortest relevant section of the busbar follows.

[0021] At least one separation line is preferably connected in a straight, wavy, or serpentine manner between the side edges of two opposing functional elements. However, other patterns having one or more separation lines can also be considered.

[0022] The segments of the planar electrodes are preferably arranged essentially parallel to each other, and the segments extend continuously from one side edge of the functional element to the opposite side edge.

[0023] The number of segments within the planar electrode may vary depending on the application of the glazing, and is generally 2 to 20, preferably 3 to 10.

[0024] Electrical contact between the external power source and the busbar is realized by a suitable connecting cable, such as a foil conductor, for example. External control elements suitable for controlling individual segments are known to those skilled in the art.

[0025] Electrical control of the functional element is performed, for example, by switches or rotary or sliding control devices integrated into vehicle components. However, control buttons, for example, capacitive buttons, may also be integrated into the composite glass. Alternatively, the functional element may be controlled by a non-contact method (e.g., gesture recognition) or by the state of the pupil or eyelid determined by a camera and a suitable electronic evaluation device.

[0026] At least one separator is introduced into the planar electrode so that the segments of the planar electrode are electrically insulated from one another. Since individual segments are connected to a voltage source independently through individual sections of the busbar, they can be controlled separately. Thus, different areas of the functional element can be switched independently. Particularly preferably, the segments are arranged horizontally at the installation location. Thus, the height of the opaque area of ​​the functional element can be controlled by the user. Here, the term "horizontal" should be interpreted broadly and refers to the direction of propagation connecting the side edges of the composite glass, for example, the side edges of the windshield or roof glass. The separator does not necessarily have to be straight, but may be slightly curved, preferably adjusted to the possible curvature of the nearest glass edge, and particularly substantially parallel to the front roof edge of the windshield. Of course, a vertical separator can also be considered.

[0027] The width of the separation line is, for example, 5 μm to 500 μm, particularly 20 μm to 200 μm. The width of the segment, that is, the distance between adjacent separation lines, can be appropriately selected by a person skilled in the art according to the needs of the individual case.

[0028] Separation lines can be introduced by laser ablation, mechanical cutting, or etching during the production of functional devices. Already stacked multilayer films can also be subsequently separated by laser removal.

[0029] A conductor bar (bus bar) is connected to a planar electrode, for example, as a strip of electrically conductive material or an electrically conductive imprint. The bus bar is preferably designed with an electrically conductive imprint containing silver.

[0030] The functional device can be optionally designed as a PDLC device, an SPD device, an electrochromic or electroluminescent device, wherein the composition of the active layer varies depending on the type of functional device. The aforementioned functional device and its structure are known to those skilled in the art.

[0031] The functional element is preferably an electrochromic functional element, and the active layer is an electrochromic layer. The active layer of the electrochromic functional element is an electrochemically active layer. The transmittance of visible light depends on the ion storage rate of the active layer, and ions are provided, for example, by an ion storage layer between the active layer and the surface electrode. The transmittance may be affected by the voltage applied to the surface electrode, which induces ion migration. A suitable functional layer contains, for example, at least tungsten oxide or vanadium oxide. Electrochromic functional elements are known, for example, in WO 2012007334 A1, US 20120026573 A1, WO 2010147494 A1, and EP 1862849 A1.

[0032] In an additional embodiment, the functional element is a PDLC (polymer dispersed liquid crystal) functional element. The active layer of the PDLC functional element contains liquid crystals embedded in a polymer matrix. When no voltage is applied to the planar electrode, the liquid crystals are arranged in a disordered manner, causing light passing through the active layer to scatter strongly. When a voltage is applied to the planar electrode, the liquid crystals are aligned in a common direction, increasing the transmittance of light passing through the active layer. Such a functional element is known, for example, in DE 102008026339 A1.

[0033] In a further preferred embodiment, the functional element is a suspended partcile device (SPD) functional element. The active layer contains suspended particles, and the absorption of light through the active layer can be changed by applying a voltage to a planar electrode. The change in absorption is based on the alignment of rod-shaped particles in an electric field when an electric voltage is applied. SPD functional elements are known, for example, in EP 0876608 B1 and WO 2011033313 A1.

[0034] In the case of an electroluminescent functional device, the active layer contains an electroluminescent material, in particular an organic electroluminescent material that is excited to emit light by the application of voltage. Electroluminescent functional devices are known, for example, in US 2004227462 A1 and WO 2010112789 A2. Electroluminescent functional devices can be used as simple light sources or displayed as a display with a desired expression.

[0035] The first busbar and the second busbar include an electrically conductive structure, preferably containing silver, and have a thickness of 5 μm to 40 μm.

[0036] A potential difference is generated between the first planar electrode and the second planar electrode as the busbar is connected to an external voltage source.

[0037] Busbars can be attached, in particular, by placement, printing, soldering, or bonding.

[0038] In a preferred embodiment, the busbar is designed as a conductive structure that is printed on and baked in. The printed busbar contains at least one metal, preferably silver. Electrical conductivity is achieved preferably through metal particles contained in the busbar, particularly preferably through silver particles. The metal particles may be present within an organic and / or inorganic matrix, such as a paste or ink, preferably a baked screen printing paste containing glass frit. The layer thickness of the printed busbar is preferably 5 μm to 40 μm, particularly preferably 8 μm to 20 μm, and very particularly 10 μm to 15 μm. A printed busbar of this thickness is technically simple to implement and has an advantageous current carrying capacity.

[0039] Alternatively, the busbar is designed as a strip of electrically conductive film. The busbar contains, for example, at least aluminum, copper, tin-plated copper, gold, silver, zinc, tungsten and / or tin, or alloys thereof. The thickness of the strip is preferably 10 μm to 500 μm, particularly preferably 30 μm to 300 μm. A busbar made of an electrically conductive film of this thickness is technically simple to implement and has an advantageous current carrying capacity. The strip can be electrically connected to a planar electrode, for example, through a soldering compound, through an electrically conductive adhesive or electrically conductive adhesive tape, or by direct application. To improve the conductivity of the connection, a silver-containing paste can be placed between the planar electrode and the busbar, for example.

[0040] The first planar electrode and the second planar electrode are each formed by an electrically conductive layer. These electrically conductive layers contain at least one metal, metal alloy, or transparent conductive oxide, preferably a transparent conductive oxide, and have a thickness of 10 nm to 2 μm. The planar electrodes are preferably transparent. Here, "transparent" means to be transparent to electromagnetic radiation, preferably electromagnetic radiation with a wavelength of 300 nm to 1300 nm, particularly visible light. The electrically conductive layer according to the present invention is known, for example, in DE 20 2008 017 611 U1, EP 0 847 965 B1, or WO 2012 / 052315 A1. It generally comprises one or more, for example, two, three, or four electrically conductive individual functional layers. The functional individual layers preferably comprise at least one metal or metal alloy such as silver, gold, copper, nickel, and / or chromium. The individual functional layer preferably contains at least 90 weight percent of metal, particularly at least 99.9 weight percent of metal. The individual functional layer may be composed of a metal or a metal alloy. The individual functional layer particularly preferably contains silver or a silver-containing alloy. Such an individual functional layer has particularly advantageous electrical conductivity within the visible spectral range, and at the same time also has high transmittance. The thickness of the individual functional layer is preferably 5 nm to 50 nm, and particularly preferably 8 nm to 25 nm. In this thickness range, advantageously high transmittance and particularly advantageous electrical conductivity are achieved within the visible spectral range.

[0041] In principle, a planar electrode can be formed by any electrically conductive layer that can be electrically contacted.

[0042] The functional element is preferably provided as a multilayer film having two external carrier films. In such a multilayer film, a planar electrode and an active layer are arranged between the two carrier films. Here, the term "external carrier film" means that the carrier film forms two surfaces of the multilayer film. By this, the functional element can be provided as a laminated film that can be advantageously processed. The functional element is advantageously protected from damage, particularly corrosion, by the carrier films. The multilayer film comprises at least one first carrier film, a first planar electrode, an active layer, a second planar electrode, and a second carrier film in this order.

[0043] The first carrier film and / or the second carrier film preferably contain one or more polymers that are not completely melted in an autoclaving process, preferably polyethylene terephthalate (PET). Particularly preferably, the first carrier film and the second carrier film are composed of PET films. This is particularly advantageous with respect to the stability of the multilayer film. However, the carrier film may also contain, for example, ethylene vinyl acetate (EVA) and / or polyvinyl butyral (PVB), polypropylene, polycarbonate, polymethyl methacrylate, polyacrylate, polyvinyl chloride, polyacetate resin, casting resin, acrylate, fluorinated ethylene propylene, polyvinyl fluoride, and / or ethylene tetrafluoroethylene. The thickness of each carrier film is preferably 0.1 mm to 1 mm, particularly preferably 0.1 mm to 0.2 mm. The carrier film according to the present invention is preferably transparent. The planar electrode is preferably arranged on the surface of the carrier film, that is, on exactly one of the two sides of the carrier film (i.e., the front or back side). The carrier film is oriented within the layer stack of the multilayer film so that the planar electrode is arranged adjacent to the active layer.

[0044] In the context of the present invention, electrically controllable optical properties are understood to mean not only continuously controllable properties, but also properties that can be switched between two or more individual states.

[0045] In addition to the active layer and planar electrode, the functional element may have other layers known in themselves, such as a barrier layer, a blocking layer, an anti-reflection layer, a protective layer, and / or a planarization layer.

[0046] Functional elements as multilayer films are commercially available. Functional elements are generally cut from larger-dimensional multilayer films into desired shapes and sizes. For example, they can be cut mechanically using a knife. In advantageous embodiments, they can be cut by a laser. In this case, the side edges were found to be more stable than those from mechanical cutting. In the case of mechanically cut side edges, there may be a risk of material shrinkage, so to speak, which is visually noticeable and negatively affects the aesthetics of the glass plate.

[0047] In an advantageous embodiment, the functional element has an edge seal. The edge seal covers the side edges of the functional element and, in particular, prevents chemical components of the thermoplastic intermediate layer, such as plasticizers, from diffusing into the active layer. The edges are sealed with a clear, colorless adhesive or clear, colorless adhesive tape along at least the bottom edge of the functional element visible through the windshield, preferably along all side edges. For example, acrylic or silicone-based adhesive tape can be used as the edge seal. A colorless, clear edge seal has the advantage of not obstructing viewing through the functional element. Such an edge seal is preferably applied even to side edges that are not visible.

[0048] The present invention also relates to a composite plate glass comprising at least a functional element according to the present invention, a thermoplastic intermediate layer, a first plate glass, and a second plate glass, wherein the thermoplastic intermediate layer comprises a first thermoplastic composite film arranged between the functional element and the first plate glass and a second thermoplastic composite film arranged between the functional element and the second plate glass. By doing so, the functional element can be safely integrated into the composite plate glass by the thermoplastic intermediate layer.

[0049] In a state where composite plate glass is installed in a vehicle or building, the first plate glass and the second plate glass of the composite plate glass according to the present invention refer to an inner plate glass and an outer plate glass.

[0050] A functional element is integrated through an intermediate layer between a first glass plate and a second glass plate of composite glass. Here, the intermediate layer comprises a first thermoplastic composite film connecting the functional element to the first glass plate and a second thermoplastic composite film connecting the functional element to the second glass plate. Typically, the intermediate layer is formed by at least first and second thermoplastic composite films arranged flatly with respect to each other and laminated together, and the functional element is inserted between the two layers. The region of the composite film overlapping with the functional element forms a region connecting the functional element to the glass plate. In other regions of the glass plate where the thermoplastic composite films are in direct contact with each other, they may fuse during lamination so that the two original layers are no longer distinguishable and instead a homogeneous intermediate layer may exist.

[0051] The thermoplastic composite film may be formed, for example, by a single thermoplastic film. The thermoplastic composite film may also be formed from sections of various thermoplastic films with their side edges attached to each other. In addition to the first thermoplastic composite film or the second thermoplastic composite film, there may be additional thermoplastic composite films. If necessary, these films may also be used to embed additional films with functional layers, such as an infrared reflective layer or an acoustic damping layer.

[0052] Thermoplastic composite films may also contain colored or colored regions. Such films can be obtained, for example, by co-extrusion. Alternatively, a thermoplastic composite film can be formed by combining uncolored film portions with colored or colored film portions. The colored or colored regions may be uniformly colored or colored; that is, they may have position-independent transmittance. However, the hue or coloring may be non-uniform, and a transmission profile, in particular, may be realized.

[0053] In one possible embodiment, the composite plate glass is the windshield of a vehicle. The windshield includes an upper edge and a lower edge, and two side edges extending between the upper edge and the lower edge. The upper edge refers to the edge intended to face upward toward the vehicle roof at the installed position. The upper edge is generally referred to as the roof edge or front roof edge. The lower edge refers to the edge intended to face downward toward the vehicle engine hood at the installed position. The lower edge is generally referred to as the engine edge.

[0054] The windshield has a central field of view and has high specifications for optical quality. The central field of view must have high light transmittance (generally 70% or more). The said central field of view is the field of view specifically referred to by those skilled in the art as field of view B, field of view area B, or area B. Field of view B and its technical specifications are defined in United Nations / European Economic Commission (UN / ECE) Regulation No. 43 (ECE-R43, "Uniform provisions concerning the approval of safety glazing materials and their installation on vehicles"). Here, field of view B is defined in Appendix 18.

[0055] In one possible embodiment of the windshield, the functional element serves as a sunshade and is positioned over the central field of view (field of view B). This means that the functional element is placed in the area between the central field of view and the front roof edge of the windshield. The functional element does not need to cover the entire area but is located entirely within this area and is not projected onto the central field of view. That is, the functional element is located at a smaller distance from the top edge of the windshield than the central field of view area. Therefore, the transmittance of the central field of view is not compromised by the functional element positioned in a similar location to a conventional mechanical sunshade in a folded state.

[0056] The intermediate layer in the central field of view of the windshield is clear and transparent. This ensures that the field of view through the central field of view is not restricted, allowing plate glass to be used as the windshield. A transparent thermoplastic intermediate layer refers to a layer having a light transmittance of 70% or more, preferably 80% or more, in the visible light spectrum range. According to ECE-R43, the transparent intermediate layer is present at least in field of view A, and preferably in field of view B as well.

[0057] The windshield is preferably for automobiles, particularly preferably for passenger cars.

[0058] In one possible embodiment, the region of the thermoplastic intermediate layer to which the functional element is connected to the outer glass or inner glass is colored or tinted. Accordingly, the transmittance of this region in the visible spectrum range is reduced compared to the uncolored or uncolored layer. Thus, the tinted / colored region of the thermoplastic intermediate layer lowers the transmittance of the windshield in the shading area. In particular, since coloring produces a more neutral appearance, the aesthetic impression of the functional element is improved, which is a greater pleasure for the observer.

[0059] In a further preferred embodiment of the composite plate glass according to the present invention, the composite plate glass is used as a roof plate glass of a vehicle. The roof plate glass consists of a front roof edge adjacent to the windshield of the vehicle, a rear roof edge pointing toward the rear window, and two side edges extending along the vehicle door between the front roof edge and the rear. Functional elements are designed as large-area sunshades of the roof plate glass, and the functional elements are arranged in an area of ​​at least 80%, preferably at least 90%, for example 100%, of the entire visually transparent area of ​​the roof plate glass.

[0060] Busbars located at the edges of composite glass used as roof glass or windshields are typically laminated with an opaque cover imprint applied to the edge area of ​​the glass. When a functional element is used as a windshield sunshade, the edge of the functional element in contact with the visually transparent windshield area generally remains without a cover imprint.

[0061] In a preferred embodiment, the functional element, more precisely, the side edge of the functional element, is surrounded by a thermoplastic frame film. The frame film is a frame-shaped design with a groove into which the functional element is inserted. The thermoplastic frame film can be made by cutting a thermoplastic film to create a groove. Alternatively, the thermoplastic frame film may consist of multiple film sections surrounding the functional element. Thus, in a preferred embodiment, the intermediate layer is formed by a total of three or more thermoplastic composite films arranged flatly relative to each other, and the frame film serving as the intermediate layer has a groove into which the functional element is arranged. During the manufacturing process, the thermoplastic frame film is arranged between the first thermoplastic composite film and the second thermoplastic composite film, wherein the side edges of all thermoplastic films are preferably congruent. The thermoplastic frame film preferably has approximately the same thickness as the functional element. This can compensate for local thickness differences in the composite glass caused by locally separated functional elements, thereby preventing glass breakage during lamination. If functional elements are introduced over a large area of ​​composite glass, a frame film may not be necessary.

[0062] The side edge of the functional element visible when viewed through the composite glass is preferably aligned at the same height as the thermoplastic frame film so that there is no gap between the side edge of the functional element and the associated side edge of the thermoplastic frame film. This applies particularly to the lower edge of the functional element, such as the awning of the windshield, where this edge is typically visible. Thus, the boundary between the thermoplastic frame film and the functional element is visually less noticeable.

[0063] Automotive glazing, particularly windshields, rear windows, and roof glass, generally has a perimeter cover imprint made of opaque enamel, which serves to protect the adhesive used to install the glass from UV radiation and to optically shield it. This perimeter cover imprint is also preferably used to shield the edges of functional elements located in the edge regions of the glazing. Busbars and necessary electrical connections are also attached to the cover imprint area. In this way, functional elements are advantageously integrated into the appearance of the composite glass. Preferably, at least the glass used as the outer glass has such a cover imprint, and particularly preferably, both the first glass and the second glass (inner glass and outer glass) are printed so that they are transparent from both sides.

[0064] The functional element may have a groove or a hole in, for example, a sensor window or camera window area. In these areas, a sensor or camera whose function may be impaired by a controllable functional element of the beam path, such as a rain sensor, is to be mounted.

[0065] The functional element is preferably arranged across the entire width of the composite glass plate, excluding, for example, a double edge region having a width of 2 mm to 20 mm. The functional element is also preferably located at a distance, for example, of 2 mm to 20 mm from the upper edge. Thus, the functional element is encapsulated within the intermediate layer and protected from contact with the surrounding atmosphere and corrosion.

[0066] The first thermoplastic composite film and the second thermoplastic composite film and optionally also the thermoplastic frame film preferably contain at least polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) and / or polyurethane (PU), and particularly preferably contain PVB.

[0067] The thickness of each thermoplastic composite film and frame film is preferably 0.2 mm to 2 mm, particularly preferably 0.3 mm to 1 mm, particularly 0.3 mm to 0.5 mm, for example 0.38 mm.

[0068] The first and second glass panes are preferably made of glass, and particularly preferably, soda-lime glass, which is the standard for window panes. However, the panes may also be made of other types of glass, e.g., quartz glass, borosilicate glass, or aluminosilicate glass, or hard and clear plastic, e.g., polycarbonate or polymethyl methacrylate. The panes may be transparent, tinted, or colored. When the composite panes are used as windshields, they must have sufficient light transmittance in the central viewing area, and according to ECE-R43, at least 70% is preferred in the visually clear main area A.

[0069] The first glass plate, the second glass plate and / or the intermediate layer may additionally have a suitable coating known in itself, such as an anti-reflective coating, a non-stick coating, a scratch-resistant coating, a photocatalytic coating, a UV-blocking coating, or a low-e coating.

[0070] The thicknesses of the first glass plate and the second glass plate can vary widely and thus be adapted to the requirements of individual cases. The thicknesses of the first glass plate and the second glass plate are preferably 0.5 mm to 5 mm, particularly preferably 1 mm to 3 mm.

[0071] The present invention also includes a method for switching a functional element according to the present invention, wherein a first voltage (U1) is applied between at least a first section of a first busbar and a first section of a second busbar. The first voltage (U1) corresponds to the switching voltage of the functional element, that is, the voltage at which the functional element is completely switched to an active state. A complete switch to an active state can be understood from the fact that no further change occurs in the optical characteristics of the functional element even if the applied voltage is further increased. A second voltage U2, having an absolute value smaller than that of voltage U1, is applied between a second section of the first busbar and a second section of the second busbar. Therefore, a complete switch to an active state does not occur in the second region of the functional element associated with the second section of the first busbar and the second section of the second busbar. In contrast, a complete switch to an active state occurs in the first region of the functional element associated with the first section of the first busbar and the first section of the second busbar. Therefore, the first region of the active state is adjacent to the second region of the partially active state, and a visually attractive profile of the functional element for optically controllable characteristics is generated.

[0072] The third region of the functional element contacted by the third section of the first busbar and the third section of the second busbar is preferably adjacent to the second region of the functional element associated with the second section of the first busbar and the second section of the second busbar. When no voltage is applied to this third region, the second region in a partially activated state forms a visually attractive transition between the fully activated first region and the inactive third region.

[0073] In a preferred embodiment of the above method, the second voltage (U2) is increased to the absolute value of the first voltage (U1) after a variablely definable period, thereby fully activating the second region as well. It is particularly preferable that the third voltage (U3) is subsequently or simultaneously applied between the third section of the first busbar and the third section of the second busbar, wherein the absolute value of the third voltage is lower than the absolute value of the voltage U1. Thus, a partial switching process of the functional element also occurs in the third region of the functional element to which the voltage U3 is applied. To an observer of the functional element, the switching process appears as the active region of the functional element propagating like a wave.

[0074] Particularly preferably, the method according to the present invention for switching a functional element according to the present invention comprises the following steps:

[0075] a) Between the n-th section of the first busbar and the n-th section of the second busbar, a first voltage (U1) corresponding to the switching voltage of the functional element is applied, and

[0076] b) A second voltage (U2) is applied between the (n+1)th section of the first busbar and the (n+1)th section of the second busbar, and

[0077] c) Increase the voltage between the (n+1)th section of the first busbar and the (n+1)th section of the second busbar to the absolute value of the first voltage (U1), and

[0078] d) A second voltage (U2) is applied between the (n+2)th section of the first busbar and the (n+2)th section of the second busbar, and

[0079] e) Steps c) and d) are repeated until a first voltage (U1) is applied between all sections of the first busbar and the relevant sections of the second busbar.

[0080] The n-th section and the (n+1)-th section of the busbar may or may not be adjacent to each other. If the functional element includes one or more first busbars and / or one or more second busbars, the n-th section and the (n+1)-th section of the busbar may be placed on different side edges of the functional element. In this way, a gradual transition of the functional element may occur depending on the arrangement of the controlled sections and sequences, optionally a gradient may be provided, or the functional element may be transitioned stepwise from an inactive state to an active state.

[0081] In particular, the second voltage (U2) is 10% to 80% of the first voltage (U1), preferably 20% to 50%. Partial switching of the active layer is particularly preferred within these regions. Changes in optical properties are, on the one hand, clearly noticeable and clearly distinguishable from the inactive region of the functional element, and on the other hand, substantially weaker than in the region of the fully activated functional element.

[0082] Applying voltage to the region of the functional element and monitoring the voltage profile accordingly can be performed by a control device known to those skilled in the art. Here, excessive charging or discharging of the functional element is prevented to prevent damage to the active layer over the long term. To prevent damage, it is desirable not to apply a constant voltage, and the state of each region is monitored by measuring the open-circuit voltage between the busbar sections of the corresponding region. Here, the open-circuit voltage should be maintained at approximately constant levels. Brief explanation of the drawing

[0083] The present invention is described in more detail with reference to the drawings and exemplary embodiments. The drawings are schematic representations and are not to an exact scale. The drawings do not limit the invention in any way. The contents shown are as follows. FIGS. 1a to 1e are various drawings of a functional element according to the present invention, FIGS. 2a and 2b show a composite plate glass including a functional element according to the present invention, FIGS. 3a and 3b show a functional element according to the present invention of a composite plate glass according to FIGS. 2a and 2b, and FIGS. 4a to 4c schematically illustrate the switching process of a composite plate glass according to the present invention. Specific details for implementing the invention

[0084] FIGS. 1a to 1e illustrate a functional element (5) according to the present invention comprising four side edges (4.1, 4.2, 4.3, 4.4). The functional element (5) is a multilayer film having electro-optical properties, composed of an active layer (11) between two planar electrodes (12, 13) and two carrier films (14, 15). The active layer (11) is an electrochromic layer whose color changes as a function of the voltage applied to the planar electrodes, thereby allowing for control of optical properties. The carrier films (14, 15) are made of PET and have a thickness of, for example, 0.125 mm. The carrier films (14, 15) have a coating facing the active layer (11), made of ITO with a thickness of about 100 nm, which forms the first planar electrode (12) and the second planar electrode (13). Planar electrodes (12, 13) are connected to an onboard electrical system via busbars (18, 19) and a connecting cable (not shown). The busbars (18, 19) are divided into sections 18.n and 19.n by a separator (16), and these sections can be controlled individually via the connecting cable. FIG. 1a shows a top view of a first carrier film (14) of a functional element (5). A first recess (10.1) is introduced into the first carrier film (14) along the side edges (4.1, 4.2, 4.3, 4.4) of the functional element (5), and the first carrier film (14) and the first planar electrode (12) on it are removed in the area of ​​the first recess (10.1). In this area, the active layer (11) is also removed so that the second planar electrode (13) is exposed. A second busbar (19) is attached peripherically along side edges (4.1, 4.2, 4.3, 4.4) on the surface of a first carrier film (14) facing away from the first planar electrode (12), and the second busbar extends through the first concave area (10.1) and electrically contacts the second planar electrode (13). FIG. 1B illustrates a plan view of the second carrier film (15) of the functional element (5) according to FIG. 1A. The second carrier film (15) has side edges (4.1, 4.2, 4.4.The first carrier film (14) has a second recess (10.2) that is alternately attached to the first recess (10.1) along the periphery along 3, 4.4). The first bus bar (18) is attached peripherily along the side edges (4.1, 4.2, 4.3, 4.4) on the surface of the second carrier film (15) away from the second planar electrode (13), and the first bus bar extends through the second recess in the area of ​​the second recess (10.2) and electrically contacts the first planar electrode (12). FIG. 1c shows a cross-section of the functional film (5) along the cutting line AA' of FIG. 1a, and FIG. 1d shows a cross-section along the cutting line BB' of FIG. 1a. FIG. 1e shows the functional film (5) as a plan view of the side edge (4.3). A first bus bar (18) and a second bus bar (19) are provided around the functional element (5), so that a particularly uniform switching process of the functional element (5) can be created.

[0085] FIGS. 2a and 2b illustrate an example in which a composite plate glass (20) according to the present invention is implemented as a roof plate glass, wherein the plan view is shown in FIG. 2a and FIG. 2b is a cross-sectional view along the cutting line CC' of FIG. 2a. The roof plate glass includes a first plate glass (1) that serves as an outer plate glass and a second plate glass (2) that serves as an inner plate glass. In this case, the inner plate glass is a plate glass facing the interior of the vehicle, and the outer plate glass is a plate glass facing the external environment of the vehicle. The first plate glass (1) and the second plate glass (2) are connected to each other through an intermediate layer (3). The first plate glass (1) is made of transparent soda-lime glass and has a thickness of 2.1 mm. The second plate glass (2) is made of soda-lime glass with a thickness of 1.6 mm and is colored gray. The colored inner glass contributes to the attractive appearance of the window when viewed by a vehicle occupant through the roof panel. The composite glass as roof glass has a front roof edge (D) facing the front glass at the installed location and a rear roof panel (D') facing the rear window at the installed location.

[0086] A functional element (5) is mounted on the roof glass as a large-area sunshade, wherein the functional element (5) is an electrochromic functional element embedded in the intermediate layer (3). The intermediate layer (3) comprises a total of three thermoplastic composite films (6, 7, 8), each film being formed from a thermoplastic film made of PVB with a thickness of 0.38 mm. The first thermoplastic composite film (6) is connected to the first glass plate (1), and the second thermoplastic composite film (7) is connected to the second glass plate (2). The thermoplastic frame film (8) located between them has an incision into which the functional element (5) is inserted accurately, that is, at the same height, on all sides. Thus, the third thermoplastic layer forms a kind of frame for the functional element (5), thereby encapsulating and protecting the functional element (5) with a thermoplastic material. The thermoplastic composite films (6, 7, 8) are optionally colored, and one or more of the films may be completely or partially colored. Depending on the thickness difference that appears in relation to the thickness of the functional element (5) and the area without the functional element (5), the frame film (8) may be omitted. This is further dependent on the complexity of the curvature of the composite glass plate. Generally, the frame film may be omitted when the thickness difference between the area with the functional element and the area without the functional element is small and the complexity of the curvature is low.

[0087] Optionally, an additional thermoplastic composite film (not shown) may be introduced adjacent to the outer glass plate (first glass plate 1). For example, a carrier film having a functional layer may be incorporated through an additional thermoplastic composite film, for example, a carrier film having an infrared reflective coating. The infrared reflective coating is oriented here toward the first glass plate (1) (outer glass plate) to serve to reduce heating of the passenger compartment by solar radiation.

[0088] The roof glass has a peripheral cover imprint (9) that covers both the composite glass bonded to itself and the planar electrode of the functional element (5) electrically contacting. The peripheral cover imprint (9) is formed with opaque enamel on the inner surface (facing the interior of the vehicle at the installation location) of the first glass (1) and the second glass (2). The distance from the front roof edge (D), the rear roof edge (D'), and the side edge of the roof glass to the functional element (5) is shorter than the width of the cover imprint (9), so that the side edges (4.1, 4.2, 4.3, 4.4) of the functional element (5) are covered by the cover imprint (9). In this case, the electrical connection is also conveniently applied to the area of ​​the cover imprint (9) and advantageously laminated.

[0089] In the thermoplastic composite film (6, 7) and the thermoplastic frame film (8), a so-called "high-flow PVB" having a stronger flow behavior than a standard PVB film may be used. Thus, the layer flows more strongly around the functional element (5), and as a result, a more uniform visual impression is produced and the transition from the functional element (5) to the frame film (8) becomes less distinct. The "high-flow PVB" may be used for only or for all of the one or more thermoplastic films (6, 7, 8) that are in direct contact with the functional element (5).

[0090] FIGS. 3a and 3b illustrate the functional element (5) of the composite plate glass (20) according to FIGS. 2a and 2b before the functional element (5) is integrated into the composite plate glass (20), where electrical contact between the functional element (5) and the busbars (18, 19) can also be seen. FIG. 3a illustrates a plan view of the functional element (5) on the first carrier film (14), and FIG. 3b illustrates a plan view of the second carrier film (15). The functional element (5) substantially corresponds to that depicted in FIGS. 1a through 1e. In contrast, at least the first planar electrode (12) is introduced with a separating line. Two of these separating lines (16) extend continuously between the first side edge (4.1) and the fourth side edge (4.4) and divide the first planar electrode (12) into several regions (17) that are opposite each other and can switch independently. The first planar electrode (12) has a separation line (16) having a width of 200 μm each, introduced, for example, by a laser method. The separation line (16) electrically separates regions (17) from each other. The number of regions (17) can be freely selected according to the application field or customer request. Preferably, the separation line (16) is introduced to divide the regions (17) into the first planar electrode (12), the second planar electrode (14), and the active layer (11). The first busbar (18) and the second busbar (19) are divided by the separation line (16) into a section (18.n) of the first busbar (18) and a section (19.n) of the second busbar (19). In this case, the separation line (16) is introduced into the busbar (19) between each adjacent first recess (10.1) to divide the second busbar (19). A separator line (16) is introduced into the first busbar (18) between adjacent second recesses (10.2). Thus, electrically independently controllable sections (18.n, 19.n) of the busbars (18, 19) are placed within each recess (10). Thus, individual partial regions can be controlled independently of each other even within the region (17).A distinct distinction is made between regions (17), and a flow path between the active region and the inactive region of the functional element appears within the region.

[0091] Individual partial regions can be controlled independently of each other even within region (17), where a distinct distinction between regions (17) occurs and a flow path exists within the region between the active region and the inactive region of the functional element.

[0092] FIGS. 4a, 4b, and 4c illustrate exemplary schematic diagrams of the respective switching processes of the functional element (5), wherein region (17) is continuously switched from an inactive state to an active state by applying voltage to the corresponding section of the busbar. FIGS. 4a and 4b show the flow profiles of adjacent regions (17) for electrically controllable optical properties between adjacent regions (17). According to FIG. 4c, a separation line (16) is applied between regions (17), so that a sharp separation of regions is seen. Explanation of the symbols

[0093] 1. First plate glass 2 Second plate glass 3 middle layer 4.1, 4.2, 4.3, 4.4 Side edge of functional element 5 Functional element having electrically controllable optical properties 6. First thermoplastic composite film 7. Second thermoplastic composite film 8 Thermoplastic Frame Film 9 Cover Imprint 10. Concave part 10.1 First depression 10.2 Second depression 11 Active layer of the functional element (5) 12 The first planar electrode of the functional element (5) 13 The second planar electrode of the functional element (5) 14 First carrier film 15 Second carrier film 16 Separator line Area 17 18 1st Busbar 19 2nd Busbar 20 Composite Plate Glass D front roof edge of composite plate glass D' rear roof edge of composite plate glass Side edge of S composite plate glass A-A', B-B', CC' cutting lines

Claims

Claim 1 In a functional element (5) having electrically controllable optical properties having a plurality of side edges (4.1, 4.2, 4.3, 4.4), comprising a first carrier film (14) having at least a first planar electrode (12), a second carrier film (15) having a second planar electrode (13), and an active layer (11) arranged flatly between the first planar electrode (12) and the second planar electrode (13), - a first busbar (18) and a second busbar (19) are arranged on at least one first side edge (4.1), - the first carrier film (14) has at least one first concave portion (10.1), and the second carrier film (15) has at least one second concave portion (10.2), wherein - the first busbar (18) is arranged on the surface of the second carrier film (15) facing away from the second planar electrode (13) and at least one second A functional element (5) that passes through a concave portion (10.2) region and electrically contacts a first planar electrode (12), - a second bus bar (19) is arranged on the surface of a first carrier film (14) facing away from the first planar electrode (12) and passes through at least one first concave portion (10.1) region and electrically contacts a second planar electrode (13), - at least one first bus bar (18) is divided into at least one first section (18.1) and at least one second section (18.2) so that they can be controlled independently of each other and / or at least one second bus bar (19) is divided into at least one first section (19.1) and at least one second section (19.2) so that they can be controlled independently of each other, and - the first concave portion (10.1) and the second concave portion (10.2) are arranged alternately with respect to each other. Claim 2 In claim 1, at least one additional first busbar (18) and / or second busbar (19) is arranged on the second side edge (4.2) of the functional element (5). Claim 3 In claim 1 or 2, the first busbar (18) and the second busbar (19) are functional elements (5) arranged on the first side edge (4.1), the second side edge (4.2), the third side edge (4.3), and the fourth side edge (4.4), respectively. Claim 4 In claim 1 or 2, the first planar electrode (12) and / or the second planar electrode (13) comprises at least one dividing line (16) that divides the functional element (5) into regions (17) that can be switched independently of each other. Claim 5 In paragraph 1 or 2, the active layer (11) is a functional element (5) that is an electrochromic layer. Claim 6 In claim 1 or 2, the first busbar (18) and the second busbar (19) comprise an electrically conductive structure containing silver and a functional element (5) having a thickness of 5㎛ to 40㎛. Claim 7 In claim 1 or 2, the first planar electrode (12) and the second planar electrode (13) comprise at least one metal, metal alloy or transparent conductive oxide and have a thickness of 10 nm to 2 μm, forming a functional element (5). Claim 8 A composite plate glass (20) comprising a functional element (5) according to claim 1 or 2, a thermoplastic intermediate layer (3), a first plate glass (1), and a second plate glass (2), wherein the thermoplastic intermediate layer (3) has a first thermoplastic composite film (6) arranged between the functional element (5) and the first plate glass (1) and a second thermoplastic composite film (7) arranged between the functional element (5) and the second plate glass (2). Claim 9 A switching method for a functional element (5) according to claim 1 or 2, wherein a first voltage (U1) corresponding to the switching voltage of the functional element (5) is applied to at least a first section (18.1) of a first bus bar (18) and a first section (19.1) of a second bus bar (19), and a second voltage (U2) having an absolute value smaller than the absolute value of the first voltage (U1) is applied between a second section (18.2) of the first bus bar (18) and a second section (19.2) of the second bus bar (19). Claim 10 A switching method according to claim 9, wherein the second voltage (U2) is increased to the absolute value of the first voltage (U1), and the third voltage (U3), whose absolute value is smaller than the absolute value of the first voltage (U1), is applied between the third section (18.3) of the first bus bar (18) and the third section (19.3) of the second bus bar (19). Claim 11 In claim 9, a switching method comprising the following steps: a) a first voltage (U1) corresponding to the switching voltage of a functional element (5) is applied between the n-th section (18.n) of the first busbar (18) and the n-th section (19.n) of the second busbar (19); b) a second voltage (U2) is applied between the (n+1)-th section (18.n+1) of the first busbar (18) and the (n+1)-th section (19.n+1) of the second busbar (19); c) the voltage between the (n+1)-th section (18.n+1) of the first busbar (18) and the (n+1)-th section (19.n+1) of the second busbar (19) is increased to the absolute value of the first voltage (U1); and d) the (n+2)-th section (18.n+2) of the first busbar (18) and the second busbar (19) A switching method in which a second voltage (U2) is applied between the (n+2)th section (19.n+2), and c) and d) are repeated until a first voltage (U1) is applied between all sections of the first busbar (18) and the associated section of the second busbar (19). Claim 12 A switching method according to claim 9, wherein the second voltage (U2) is 10% to 80% of the first voltage (U1) or 20% to 50% of the first voltage (U1).

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