Electrochromic functional element, glazing unit, and method for electrically controlling an electrochromic functional element

Abstract

The invention relates to an electrochromic functional element (2), comprising: - an active layer (9) with electrically controllable optical properties between a first flat electrode (10a) and a second flat electrode (10b), wherein - the electrochromic functional element (2) is electrically divided into a central region (Z) and four surrounding regions (P, P',P'',P''') by at least three coating-free separating lines (4a,4a',4a'') in the first flat electrode (10a) and at least three coating-free separating lines (4b,4b',4b'') in the second flat electrode (10b) so that the central region (Z) and the surrounding regions (P,P',P'',P''') can be electrically actuated or are electrically actuated independently.

Description

[0001] Electrochromic functional element, glazing unit and method for electrically controlling an electrochromic functional element

[0002] The invention relates to an electrochromic functional element with electrically controllable optical properties, preferably an electrochromic functional element in a glazing unit, a method for controlling the electrochromic functional element and a use of the electrochromic functional element.

[0003] Functional elements with electrically controllable optical properties are used in the industrial production of glazing units. Such glazing units are often laminated panes or insulating glazing units into which a functional element is embedded. The laminated panes consist of at least one outer pane, one inner pane, and an adhesive interlayer that connects the outer pane to the inner pane. Typical interlayers are polyvinyl butyral films, which, in addition to their adhesive properties, exhibit high toughness and high acoustic damping. The interlayer prevents the laminated glass pane from disintegrating in the event of damage. The laminated pane merely cracks but remains dimensionally stable.

[0004] Electrochromic functional elements have attracted considerable interest due to their potential applications in improving the functionality of homes and vehicles. Based on the use of electrolytes, electrochromic functional elements can be divided into several types, including gel, liquid, and solid electrochromic functional elements. When assembling electrochromic functional elements with liquid or gel electrolytes, the working electrode and counter electrode must be separated by a spacer, with the electrolyte filled into a gap between them. The cavity is then sealed, for example, with epoxy resin. To prevent the electrolytes from leaking out of the liquid or gel-based electrochromic functional elements, complicated sealing and edge designs are required. Although the addition of polymer thickeners (such as PVA, PMMA, PVDF-HFP, etc.)) to form gel electrolytes can minimize leakage problems, the total amount of polymer matrix is ​​generally less than 20 wt.% to maintain appropriate ionic conductivity. The majority of the electrolyte layer still contains liquid or gel, and mechanical robustness remains an issue.

[0005] Solid-based electrochromic functional elements (also called solid-state electrochromic functional elements) are desirable for many applications because they offer numerous advantages over liquid / gel-based electrochromic functional elements, such as higher safety, longer service life, and the possibility of roll-to-roll processing. Examples of solid-based electrochromic functional elements are known, for example, from WO 2020056326 A1.

[0006] Electrochromic functional elements are commercially available as multilayer films. The surface electrodes required for applying a voltage are arranged, for example, between two PET carrier films. During the production of the glazing unit, the electrochromic functional element is cut out of the multilayer film in the desired size and shape and inserted, for example, between two films made of an adhesive interlayer. The surface electrodes are usually electrically contacted with busbars and electrically connected to an electrical control unit (ECU) via flat conductors outside the laminated pane. The control unit is designed to apply an electrical control voltage between the surface electrodes.

[0007] Surface electrodes for contacting in electrochromic functional elements can be divided into separate segments, as is known, for example, from US 2013 / 0057939 A1 or CN 109 031 836 B.

[0008] Due to the high sheet resistance of the surface electrodes, the change in optical properties with changing electrical voltage is significantly delayed in areas farther away from the electrical connections (especially the bus bars), i.e., especially in the interior. This leads to an inhomogeneous change in transparency, also known as the halo effect.

[0009] The object of the present invention is to provide an improved electrochromic functional element and an improved method in which electrochromic functional elements can be switched faster and more homogeneously across their surface.

[0010] The object of the present invention is achieved by an electrochromic functional element according to independent claim 1. Preferred embodiments of the invention emerge from the subclaims.

[0011] The object is achieved according to the invention by an electrochromic functional element, comprising: an active layer with electrically controllable optical properties between a first surface electrode and a second surface electrode, wherein the electrochromic functional element is electrically and preferably galvanically divided into a central region and four surrounding regions by at least three coating-free separating lines in the first surface electrode and at least three coating-free separating lines in the second surface electrode, so that the central region and the surrounding regions can be or are electrically controlled independently.

[0012] The coating-free separating lines electrically insulate the adjacent areas of the surface electrodes from one another, in particular galvanically (i.e., for direct currents). The coating-free separating lines can be produced by locally removing the surface electrodes, for example, by mechanical structuring or laser structuring. The separating lines preferably have a width of a few micrometers, preferably from 1 pm to 100 pm, and in particular from 30 pm to 100 pm. Within the scope of the present invention, a linear change in the chemical properties and, in particular, in the surface resistance, for example, due to local oxidation, is also understood as a coating-free separating line.

[0013] In an advantageous embodiment of an electrochromic functional element according to the invention, a first measuring line is formed between a first coating-free separating line and a further, fourth coating-free separating line in the first surface electrode, and a second measuring line is formed between a first coating-free separating line and a further, fourth coating-free separating line in the second surface electrode, with which a measuring voltage (sense) of the central region can be measured or is measured. The measuring voltage is the voltage that is present at the central region of the electrochromic functional element and controls the optical properties, in particular the transparency, there. The measuring lines and the currentless voltage measurement determine the applied voltage without the voltage drop due to the finite resistance of the surface electrodes.The voltage applied to the central region can therefore be compensated by the value of the voltage drop and the changes in the optical properties can be homogenized.

[0014] In a further advantageous embodiment of an electrochromic functional element according to the invention, the first and / or the second measuring line has a width of less than 1 cm, preferably from 0.5 mm to 5 mm and particularly preferably from 0.5 mm to 1 mm.

[0015] In a further advantageous embodiment of an electrochromic functional element according to the invention, the three coating-free separating lines in the first surface electrode completely insulate a section of the first surface electrode from the surrounding first surface electrode, and the three coating-free separating lines in the second surface electrode completely insulate a section of the second surface electrode electrically, preferably galvanically, from the surrounding second surface electrode. In this case, the overlapping sections form the central region according to the invention in an orthogonal projection through one of the main planes of the electrochromic functional element. The three coating-free separating lines in the first and second surface electrodes are preferably arranged directly next to one another.Particularly preferably, the first dividing line begins at a (lower or upper) side edge of the electrochromic functional element, wherein the end of the first dividing line facing away from the side edge is connected to (or merges into) a first end of the second dividing line, wherein the second end of the second dividing line is connected to (or merges into) a first end of the third dividing line and the second end of the third dividing line ends at the same side edge at which the first dividing line began. In particular, for this purpose, the first dividing line runs from the side edge into the interior of the electrochromic functional element (i.e. into the interior with respect to a plan view of or through the electrochromic functional element), the second dividing line essentially parallel to the side edge and the third dividing line back again from the interior of the electrochromic functional element to the side edge.

[0016] For example, the three dividing lines, together with the margin between the first and third dividing lines, enclose a rectangle. The resulting central area is then also rectangular. Alternatively, the second dividing line can be curved or bent, for example, in the shape of a semicircle or half an ellipse, so that the central area is correspondingly circular, elliptical, or otherwise curvilinear.

[0017] In a further advantageous embodiment of an electrochromic functional element according to the invention, the first surface electrode is electrically connected, preferably galvanically, to first collecting electrodes for electrical contact, and the second surface electrode is electrically connected, preferably galvanically, to second collecting electrodes, wherein the first collecting electrodes and second collecting electrodes are arranged on opposite sides of the electrochromic functional element. The collecting electrodes are typically arranged in the immediate vicinity of the side edge of the electrochromic functional element and are therefore easily concealed, for example, by a frame or a cover print—but at the same time, they are easily electrically connected to the outside, for example, by foil conductors.

[0018] In a further advantageous embodiment of an electrochromic functional element according to the invention, the coating-free dividing lines in the first surface electrode and the coating-free dividing lines in the second surface electrode are arranged in the central region so as to be substantially congruent with one another with respect to an orthogonal projection through a main plane of the electrochromic functional element. The main planes are formed by the two opposite surfaces of the electrochromic functional element, which run parallel to the surface electrodes.In a further advantageous embodiment of an electrochromic functional element according to the invention, a third bus bar is arranged between the first dividing line and the fourth dividing line of the second surface electrode, on the side of the electrochromic functional element opposite the first bus bars, and is electrically, preferably galvanically, connected to the first surface electrode; furthermore, a fourth bus bar is arranged between the first dividing line and the fourth dividing line of the first surface electrode, on the side of the electrochromic functional element opposite the second bus bars, and is electrically, preferably galvanically, connected to the second surface electrode.

[0019] By suitable contacting and wiring of the fourth bus bars, the surrounding areas between the central area and the first and second bus bars (at the upper and lower side edges of the electrochromic functional element) can be accelerated in their optical switching behavior and homogenized via the electrochromic functional element.

[0020] A further aspect of the invention relates to glazing with an electrochromic functional element according to the invention, preferably a laminated pane or an insulating glazing, comprising:

[0021] - a first slice, and

[0022] - an electrochromic functional element according to the invention, which is connected to the first pane in a planar manner, preferably via a thermoplastic intermediate layer or an optically transparent adhesive.

[0023] An alternative glazing according to the invention comprises an electrochromic functional element according to the invention, which is deposited on a solid carrier layer, for example a glass pane, and in particular on the first pane, for example by thin-film deposition processes such as sputtering or magnetron sputtering. Preferably, the first surface electrode, followed by a first electrochemically active layer, an electrolyte layer, optionally a further electrochemically active layer, and a second surface electrode are deposited one on top of the other on the first pane. The resulting layer stack can then be bonded to a second pane, preferably as a composite pane via a thermoplastic intermediate layer or an optically transparent adhesive, or as insulating glazing via a circumferential frame-shaped spacer.

[0024] The invention further relates to a composite pane with an electrochromic functional element, at least comprising: a first pane (for example an outer pane) and a second pane (for example an inner pane), which are firmly connected to one another via a thermoplastic intermediate layer (also called an adhesive layer) or an optically transparent adhesive, for example by lamination in the case of the thermoplastic intermediate layer, and an electrochromic functional element according to the invention, which is arranged between the first pane and the second pane.

[0025] The invention further relates to an insulating glazing with an electrochromic functional element, at least comprising: a first pane (for example an outer pane) and a second pane (for example an inner pane), which are connected to one another via a frame-shaped spacer, and an electrochromic functional element according to the invention, wherein the electrochromic functional element, which is arranged between the first pane and the second pane and is firmly connected to the first pane or the second pane via a thermoplastic intermediate layer or an optically transparent adhesive.

[0026] The invention also includes a glazing unit.

[0027] The glazing, the laminated pane, the insulating glazing, the glazing unit, and the method are presented together, with explanations and preferred embodiments referring equally to the glazing unit and the method. If preferred features are described in connection with the method, it follows that the glazing unit is preferably designed and suitable accordingly. Conversely, if preferred features are described in connection with the glazing unit, it follows that the method is preferably carried out accordingly.

[0028] A further aspect of the invention relates to a method for controlling an electrochromic functional element according to the invention, preferably a glazing according to the invention such as a composite pane according to the invention or an insulating glazing according to the invention, or a glazing unit according to the invention, wherein

[0029] A) a first control voltage U_Z is applied by a control unit to the central region of an electrochromic functional element according to the invention at least until a first measurement voltage Sense_Z is reached; B) a second control voltage U_P is applied by the control unit to the surrounding regions of the electrochromic functional element at least until a second measurement voltage Sense_P is reached, wherein the first control voltage U_Z is selected to be greater than the second control voltage U_P.

[0030] In an advantageous development of the method according to the invention, steps A) and B) are carried out repeatedly, preferably at a frequency of 0.01 Hz to 1 kHz, particularly preferably from 1 Hz to 100 Hz.

[0031] In a further advantageous development of the method according to the invention, one method step (A) or B) is carried out for a longer time, the same length of time, or a shorter time than the other method step (B) or A)). This allows for a more uniform lightening or darkening to be specifically adjusted.

[0032] In a further advantageous development of the method according to the invention, the first measurement voltage Sense_Z and the second measurement voltage Sense_P are selected to be equal to the maximum operating voltage of the electrochromic functional unit. This allows for particularly precise switching without damaging the electrochromic functional element.

[0033] A further aspect of the invention relates to a glazing unit with an electrochromic functional element according to the invention, comprising

[0034] • an electrochromic functional element according to the invention, a glazing according to the invention, for example a composite pane according to the invention or an insulating glazing according to the invention; and

[0035] • a control unit for electrically controlling the optical properties of the electrochromic functional element, wherein the control unit is intended to carry out the method according to the invention.

[0036] In an advantageous development of a glazing unit according to the invention, the control unit is designed to determine a temperature T of the electrochromic functional element, preferably via a temperature sensor, an electrical resistance of the surface electrodes or an impedance of the electrochromic functional element and is provided for determining the first electrical control voltage U_Z and / or the second electrical control voltage U_P as a function of the temperature T.

[0037] The glazing unit according to the invention with an electrochromic functional element comprises the composite pane according to the invention and a control unit for electrically controlling the optical properties of the electrochromic functional element, wherein the control unit is preferably provided to carry out the method according to the invention. The glazing unit preferably comprises the composite pane according to the invention consisting of at least a first pane (for example, an outer pane) and a second pane (for example, an inner pane), which are connected to one another via at least one thermoplastic intermediate layer. The electrochromic functional element is typically embedded in the thermoplastic intermediate layer.

[0038] Alternatively, the glazing unit preferably comprises insulating glazing according to the invention.

[0039] The glazing unit is advantageously designed to separate the interior from the exterior in a window or roof opening, for example, in a vehicle, a building, or a room. For the purposes of the invention, the "inner pane" refers to the pane facing the interior. The "outer pane" refers to the pane facing the exterior. The thermoplastic intermediate layer or the optically transparent adhesive serves to connect the two panes or one of the panes to the electrochromic functional element according to the invention.

[0040] The thermoplastic intermediate layer contains at least one thermoplastic polymer, preferably ethylene-vinyl acetate (EVA), polyvinyl butyral (PVB), polyurethane (PU), thermoplastic polyurethane (TPU), or aliphatic thermoplastic polyurethane (TPU), or mixtures or copolymers or derivatives thereof, particularly preferably PVB. The intermediate layer is typically formed from a thermoplastic film. The thickness of the intermediate layer is preferably from 0.2 mm to 2 mm, particularly preferably from 0.3 mm to 1 mm.

[0041] The first pane (e.g. the outer pane) and the second pane (e.g. the inner pane) are preferably made of glass, in particular soda-lime glass, which is common for window panes. In principle, however, the panes can also be made of other types of glass (e.g. borosilicate glass, quartz glass, aluminosilicate glass, or sapphire glass) or transparent plastics (e.g. polymethyl methacrylate or polycarbonate). The thickness of the outer pane and the inner pane can vary widely. Preferably, panes with a thickness in the range of 0.8 mm to 5 mm, more preferably from 1.4 mm to 2.5 mm, for example those with the standard thicknesses of 1.6 mm or 2.1 mm, are used.

[0042] The first pane (e.g., the outer pane), the second pane (e.g., the inner pane), and, if applicable, the thermoplastic interlayer(s) can be clear and colorless, but also tinted or colored. A corresponding glazing unit used as a windshield must provide sufficient light transmission in the central viewing area, preferably at least 70% in the main viewing area A according to ECE-R43. The outer pane and the inner panes can independently be non-tempered, semi-tempered, or toughened. If at least one of the panes is to be toughened, this can be thermally or chemically toughened.

[0043] The first pane (e.g. the outer pane), the second pane (e.g. the inner pane) and / or the intermediate layer may have further suitable coatings known per se, for example anti-reflective coatings, non-stick coatings, anti-scratch coatings, photocatalytic coatings or sun protection coatings or low-E coatings.

[0044] The first pane (e.g., the outer pane) and the second pane (e.g., the inner pane) are laminated together via the intermediate layer, for example, using autoclave processes, vacuum bag processes, vacuum ring processes, calender processes, vacuum laminators, or combinations thereof. The bonding of the outer pane and inner pane is typically achieved under the influence of heat, vacuum, and / or pressure.

[0045] The electrochromic functional element according to the invention can comprise all common electrochromic multilayer systems, for example organic electrochromic systems or inorganic electrochromic systems.

[0046] The electrochromic functional element according to the invention comprises two surface electrodes, hereinafter also referred to as electrode layers, and preferably two electrochemically active layers located between the two surface electrodes, wherein the electrochemically active layers are separated from one another by an electrolyte layer. The two active layers are each capable of reversibly incorporating small ions, wherein at least one of the two layers consists of an electrochromic material that has different oxidation states that correspond to the incorporation or decorporation state of the ions and have a different color. By applying electrical voltages of different polarity to the surface electrodes, the incorporation or decorporation of the ions can be controlled in order to specifically influence the optical transmission of the electrochromic functional element.

[0047] The layer of electrochemically active layers and the electrolyte layer in between exhibits variable optical properties that can be controlled by an applied electrical voltage.

[0048] For the purposes of the invention, electrically controllable optical properties are understood to mean those properties that can be continuously controlled, but equally also those that can be switched between two or more discrete states. The optical properties relate in particular to light transmission and / or scattering behavior.

[0049] An advantageous electrochromic functional element according to the invention comprises at least one active layer arranged between a first carrier layer and a second carrier layer.

[0050] The electrochromic functional element, consisting of surface electrodes, electrochemically active layers, and interposed electrolyte layers, is preferably arranged on a solid carrier layer (e.g., a rigid disk) or between two flexible carrier layers or foils. The control voltage for electrically controlling the optical properties is applied via the surface electrodes to the electrochemically active layer(s) and the interposed electrolyte layer. In an advantageous embodiment of the invention, the electrochromic functional element is a solid-based electrochromic functional element. Such solid-based electrochromic functional elements require only a low control voltage of a few volts and have long service lives of several hours without self-discharge.

[0051] The surface electrodes and the active layer are arranged essentially parallel to the surfaces of the first pane (e.g., the outer pane) and the second pane (e.g., the inner pane). The surface electrodes are connected or connectable to the control unit. Electrical contact, as well as the connection to the power source of the active layer, is realized by suitable connecting cables, such as flat conductors or foil conductors, which are optionally connected to the surface electrodes via so-called bus bars, such as strips of an electrically conductive material or electrically conductive prints. The thickness of the functional element is, for example, from 0.04 mm to 1 mm.

[0052] The surface electrodes are preferably configured as transparent, electrically conductive layers. The surface electrodes preferably contain at least one metal, a metal alloy, or a transparent conducting oxide (TCO). The surface electrodes can contain, for example, silver, gold, copper, nickel, chromium, tungsten, indium tin oxide (ITO), gallium-doped or aluminum-doped zinc oxide, and / or fluorine-doped or antimony-doped tin oxide. The surface electrodes preferably have a thickness of 10 nm (nanometers) to 2 pm (micrometers), more preferably 20 nm to 1 pm, and most preferably 30 nm to 500 nm.

[0053] The glazing unit according to the invention comprises an electrochromic functional element, which is preferably embedded in the intermediate layer. The functional element is typically arranged between at least two layers of thermoplastic material of the intermediate layer, being connected to the first pane (e.g., the outer pane) by the first layer and to the second pane (e.g., the inner pane) by the second layer.

[0054] A further aspect of the invention relates to a vehicle, in particular a passenger car, with the glazing unit according to the invention.

[0055] A further aspect of the invention comprises the use of the glazing unit according to the invention in means of transport for traffic on land, in the air or on water, in particular in motor vehicles, for example as a windshield, rear window, side window and / or roof window as well as architectural or facade glazing, as a functional individual piece, and as a built-in component in furniture, appliances and buildings.

[0056] The invention is explained in more detail below with reference to figures and exemplary embodiments. The figures are schematic representations and not to scale. The figures do not limit the invention in any way.

[0057] They show:

[0058] Figure 1 is a schematic representation of a glazing unit according to the invention,

[0059] Figure 2A shows a schematic representation of a further glazing unit according to the invention corresponding to a switching configuration according to method step A) of the method according to the invention;

[0060] Figure 2B schematic representation of the glazing unit from Figure 2A according to process step B) of the process according to the invention;

[0061] Figure 3A shows a schematic representation of a further glazing unit according to the invention corresponding to a switching configuration according to method step A) of the method according to the invention; and

[0062] Figure 3B schematic representation of the glazing unit from Figure 3A according to process step B) of the process according to the invention.

[0063] In the exemplary embodiments, the components described represent features of the invention that are to be considered independently of one another and which can also be regarded as part of the invention individually or in a combination other than that shown.

[0064] Numerical values ​​are generally not to be understood as exact values, but also include a tolerance of + / - 1% up to + / - 10%. Figure 1 (Fig. 1) shows a schematic representation of a glazing unit 100, which can be installed, for example, in a motor vehicle or in a building. The glazing unit 100 comprises a composite pane T, which comprises glazing 1 with an electrochromic functional element 2 according to the invention. The composite pane 1 comprises a first pane 1a, which is also referred to, for example, as the outer pane 1a, and a second pane 1b, which is also referred to, for example, as the inner pane 1b. The first pane 1a and the second pane 1b are each connected to the electrochromic functional element 2 via two thermoplastic intermediate layers 3a, 3b. The first pane 1a has a thickness of 2.1 mm and is made of soda-lime glass.The second pane 1 b has a thickness of 1.6 mm and is made of clear soda-lime glass.

[0065] The composite pane 1 is equipped in one area with the electrochromic functional element 2, which is embedded in the intermediate layer 3. The intermediate layer 3 comprises a total of three thermoplastic layers, each formed by a thermoplastic film made of PVB with a thickness of 0.38 mm. The first thermoplastic layer 3a is bonded to the outer pane 1a, the second thermoplastic layer 3b to the inner pane 1b. The intermediate third thermoplastic layer surrounds the cut-to-size electrochromic functional element 2, essentially flush on all sides (not shown here). The electrochromic functional element 2 is thus embedded all around in thermoplastic material and thus protected.

[0066] The electrochromic functional element 2 is a multilayer film, for example, consisting of a flexible, transparent plastic carrier film 8, a (first) surface electrode 10a, an active layer 9, and a (second) surface electrode 10b. The active layer 9 preferably consists of an electrolyte layer, for example, an organic solid electrolyte, and at least one ion storage layer (not shown in detail here). The plastic carrier film 8 is, for example, a PET film. The thickness of the multilayer film is, for example, 0.3 mm. The surface electrodes 10 consist, for example, of an indium tin oxide (ITO) layer with a sheet resistance between 1 ohm / square and 100 ohm / square.

[0067] In the dark state, the electrochromic functional element 2 is colored blue to gray / violet, preferably blue, gray, or violet. The transmission TL in the dark switching state is 1.3% to 9% and in the clear (transparent) state 32% to 63%, with a contrast between 7 and 24.

[0068] It is understood that other electrochemical systems, for example, those with inorganic electrolytes, can also be used as the multilayer film of the electrochromic functional element 2. Advantageously, a UV filter is arranged between the electrochromic functional element 2 and the outer surface of the laminated pane 1, for example, a PVB intermediate layer 3a or 3b with UV-filtering properties. This protects the electrochromic functional element 2 from premature aging.

[0069] The glazing unit 100 also comprises a control unit 11 (often called ECU in a motor vehicle), which is electrically connected to the surface electrodes 10 of the electrochromic functional element 2, so that an electrical (control) voltage U can be applied to the functional element 2.

[0070] The electrical (control) voltage U applied between two surface electrodes 10a, 10b of the electrochromic functional element 2 is typically a direct voltage or a pulsed direct voltage. The control unit 11 is equipped, for example, with a DC-DC converter that converts an on-board voltage (primary voltage) into a suitable direct voltage (secondary voltage).

[0071] The optical properties of the glazing unit 100 are controlled by the control unit 11. For this purpose, the control unit 11 is electrically connected to the two transparent surface electrodes 10a, 10b of the electrochromic functional element 2, for example via bus bars not shown here.

[0072] Figure 2A (Fig. 2A) and Figure 2B (Fig. 2B) show an embodiment of a glazing unit 100 according to the invention. The electrochromic functional element 2 according to the invention corresponds, for example, to that in Figure 1, so that for details reference is made to the description there. Figures 2A and 2B show the supply lines to the control electronics 11 together with the associated switches Sa, Sa', Sa", Sb, Sb' and Sb". The switches Sa, Sa', Sa", Sb, Sb' and Sb" serve for the controlled connection of the respective bus bars 5a, 5a", 5a'", 5b, 5b", 5b'" to the control electronics 11. The control electronics 11 is designed to switch the switches Sa, Sa', Sa", Sb, Sb' and Sb" accordingly.

[0073] The electrochromic functional element 2 has several separating lines: First separating lines 4a, 4a', 4a", 4a"' (drawn with dash-dot lines) are introduced into the first surface electrode 10a and electrically and in particular galvanically insulate the adjacent surface electrode regions of the first surface electrode 10a from one another. Second separating lines 4b, 4b', 4b", 4b"' (drawn with dashed lines) are introduced into the second surface electrode 10b and electrically and in particular galvanically insulate the adjacent surface electrode regions of the second surface electrode 10b from one another. The separating lines 4a, 4a', 4a", 4a"', 4b, 4b', 4b", 4b"' can be introduced into the surface electrodes 10a, 10b, for example, by laser structuring and have a width of a few micrometers, preferably from 1 pm to 100 pm and in particular from 30 pm to 100 pm, which is barely visible to the human eye.

[0074] A first measuring line 6a is formed by the dividing lines 4a"' and a section of the dividing line 4a, with which a first measuring voltage Sense+ of the central region Z can be measured. A first second measuring line 6b is formed by the dividing lines 4b"' and a section of the dividing line 4b', with which a measuring voltage Sense- of the central region Z can be measured.

[0075] The control voltages U+ and U- as well as the measuring voltages Sense+ and Sense- are connected to the respective areas of the surface electrodes 10a, 10b via supply lines, if necessary switches Sa, Sa', Sa", Sb, Sb' and Sb" and bus bars 5a, 5a', 5a", 5a'", 5b, 5b', 5b", 5b"'.

[0076] The control voltage U+ of the control unit 11 is electrically connected to the central region Z of the first surface electrode 10a via the busbar 5a'. Furthermore, the control voltage U+ of the control unit 11 is electrically connected to the surrounding regions P, P' of the first surface electrode 10a via the switches Sa, Sa' and via the busbars 5a, 5a'.

[0077] The control voltage U- of the control unit 11 is permanently electrically connected to the central region Z of the second surface electrode 10b via the busbar 5b'. Furthermore, the control voltage U- of the control unit 11 is electrically connected to the surrounding regions P, P' of the second surface electrode 10b via the switches Sb, Sb' and via the busbars 5b, 5b'.

[0078] The measuring voltage input Sense+ of the control unit 11 is electrically connected to the first measuring line 6a of the central region Z of the first surface electrode 10a in a switching state of the switch Sa" and to the control voltage line of the control voltage U+ in an alternative switching state. The measuring voltage input Sense- of the control unit 11 is electrically connected to the second measuring line 6b of the central region Z of the second surface electrode 10b in a switching state of the switch Sb" and to the control voltage line of the control voltage U- in an alternative switching state.

[0079] Figure 2A shows the switching state of method step A) according to the invention. The control voltage U+ is applied directly to the first surface electrode 10a of the central region Z, but not to the surrounding regions P, P' of the first surface electrode 10a because of the open switches Sa, Sa'. The control voltage U- is applied directly to the second surface electrode 10b of the central region Z, but not to the surrounding regions P, P' of the second surface electrode 10b because of the open switches Sb, Sb'.

[0080] The measuring voltage input Sense+ of the control unit 11 is electrically connected to the first measuring line 6a of the first surface electrode 10a and the measuring voltage input Sense- of the control unit 11 is electrically connected to the second measuring line 6b of the second surface electrode 10b, so that the sense measuring voltage Sense_Z (=Sense+ - Sense-) applied to the central area Z can be detected.

[0081] The control voltage U_Z (=U+ - U-) is now applied and increased if necessary until the sense measuring voltage in the central area Z is greater than or equal to a first measuring voltage Sense_Z.

[0082] Subsequently, in a process step B), the switching states of the switches Sa, Sa', Sa", Sb, Sb", Sb"' are changed and a control voltage U_P is applied to the surrounding areas P, P' and the central area Z.

[0083] Figure 2B shows the switching state of method step B) according to the invention. The control voltage U+ is applied directly to the first surface electrode 10a of the central region Z, and, because of the closed switches Sa, Sa', also directly to the surrounding regions P, P' of the first surface electrode 10a. The control voltage U- is applied directly to the second surface electrode 10b of the central region Z, and, because of the closed switches Sb, Sb', also directly to the surrounding regions P, P' of the second surface electrode 10b.

[0084] The switches Sa"' and Sb"' are now also closed, so that the measurement voltage input Sense+ of the control unit 11 is electrically connected to the first surface electrode 10a in the surrounding area P, P', and the measurement voltage input Sense- of the control unit 11 is electrically connected to the second surface electrode 10b in the surrounding area P, P'. This allows the sense measurement voltage (=Sense+ - Sense-) present at the surrounding area P, P' to be detected.

[0085] The second control voltage U_P (=U+ - U-) is now applied and increased if necessary until the sense measuring voltage in the central area Z is greater than or equal to a second measuring voltage Sense_P.

[0086] In an advantageous development of the method according to the invention, method step A) is then repeated, i.e. the switching configuration according to Figure 2A is adopted, and then method step B) is repeated again, i.e. the switching configuration according to Figure 2B is adopted, etc. The repetition frequency of method steps A) and B) is, for example, 1 Hz. In the method according to the invention, the first control voltage U_Z is selected to be greater than the second control voltage U_P. This also applies if the second control voltage U_P already corresponds to the maximum operating voltage of the active layer 9. The control voltage in the central region Z is reduced by the voltage drop in the surface electrodes 10a, 10b in the surrounding regions P" and P"'. By measuring the respective voltage at the central region Z via the measuring lines 6a and 6b, the voltage present in the central region Z can be precisely monitored.In particular, the first control voltage U_Z is selected such that, after the voltage drop in the surface electrodes 10a, 10b in the surrounding areas P" and P"', it is essentially equal to the maximum operating voltage of the active layer 9. This leads to a significantly accelerated switching behavior and, due to the change between the switching configurations of process steps A) and B), to an optically more homogeneous switching behavior of the electrochromic functional element 2.

[0087] Figure 3A (Fig. 3A) and Figure 3B (Fig. 3B) show a further development of the embodiment example according to the invention of a glazing unit 100 according to the invention according to Figures 2A and 2B, so that only the differences are discussed here and otherwise reference is made to the description according to Figures 2A and 2B.

[0088] Figure 3A essentially corresponds to Figure 2A and Figure 3B essentially corresponds to Figure 2B, wherein a third bus bar 5c is arranged between the first dividing line 4b and the fourth dividing line 4b"' of the second surface electrode 10b, which delimits the measuring line 6b, on the side of the electrochromic functional element 2 opposite the first bus bars 5a, 5a', 5a", 5a"' and is electrically, preferably galvanically, connected to the first surface electrode 10a.

[0089] Furthermore, a fourth bus conductor 5d is arranged between the first separating line 4a and the fourth separating line 4a"' of the first surface electrode 10a, which delimits the measuring line 6a, on the side of the electrochromic functional element 2 opposite the second bus conductors 5b, 5b', 5b", 5b"' and is electrically, preferably galvanically, connected to the second surface electrode 10b.

[0090] The third bus conductor 5c is electrically conductively, preferably galvanically, connected to the first bus conductor 5a of the first surface electrode 10a via a first additional line 7a, so that the same electrical potential is present at the third bus conductor 5c (and thus at the surrounding area P") as at the first bus conductor 5a of the first surface electrode 10a. It is understood that the third bus conductor 5c can also be connected to the bus conductor 5a" or to both bus conductors 5a and 5a". Furthermore, the fourth bus conductor 5d is electrically conductively, preferably galvanically connected to the first bus conductor 5b of the second surface electrode 10b via a second additional line 7b, so that the same electrical potential is present at the fourth bus conductor 5d (and thus at the surrounding area P") as at the second bus conductor 5b of the second surface electrode 10b.It is understood that the fourth bus bar 5d can also be connected to the bus bar 5b" or to both bus bars 5b and 5b".

[0091] In this embodiment, the switching behavior of the surrounding areas P" and P"' is accelerated and the optical impression of the electrochromic functional element 2 is further homogenized.

[0092] List of reference symbols:

[0093] 1 Glazing

[0094] T composite pane

[0095] 1a outer pane

[0096] 1b inner pane

[0097] 2 electrochromic functional element

[0098] 3 Intermediate layer

[0099] 3a first thermoplastic layer

[0100] 3b second thermoplastic layer

[0101] 4a, 4a', 4a", 4a"', 4b, 4b', 4b", 4b"' coating-free dividing line

[0102] 5a, 5a', 5a", 5a"', 5b, 5b', 5b", 5b"', 5c, 5d busbar

[0103] 6a, 6b measuring line

[0104] 7a, 7b additional line

[0105] 8 plastic carrier film

[0106] 9 active layer

[0107] 10, 10a, 10b Surface electrodes

[0108] 11 Control unit, ECU (electronic control unit)

[0109] 100 glazing units

[0110] P, P', P“, P“' surrounding area

[0111] Sat, Sb counter

[0112] Sense+, Sense- measuring voltage

[0113] U+, U- control voltage

[0114] U_P Control voltage for the ambient areas P,P',P“,P“'

[0115] U_Z Control voltage for the central area Z

[0116] T Temperature

[0117] Z Central area

Claims

Patent claims 1. An electrochromic functional element (2) comprising at least one active layer (9) with electrically controllable optical properties between a first surface electrode (10a) and a second surface electrode (10b), wherein the electrochromic functional element (2) is electrically divided into a central region (Z) and four surrounding regions (P, P', P", P"') by at least three coating-free separating lines (4a, 4a', 4a") in the first surface electrode (10a) and at least three coating-free separating lines (4b, 4b', 4b") in the second surface electrode (10b), such that the central region (Z) and the surrounding regions (P, P', P", P"') are or are electrically controllable independently of one another.

2. Electrochromic functional element (2) according to claim 1, wherein a first measuring line (6a) is formed between a first coating-free separating line (4a) and a fourth coating-free separating line (4a") in the first surface electrode (10a) and a second measuring line (6b) is formed between a first coating-free separating line (4b) and a fourth coating-free separating line (4b") in the second surface electrode (10b), with which a measuring voltage (sense) of the central region (Z) can be measured or is measured.

3. Electrochromic functional element (2) according to claim 1 or claim 2, wherein the three coating-free separating lines (4a, 4a', 4a") completely insulate a section of the first surface electrode (10a) from the surrounding first surface electrode (10a) and the three coating-free separating lines (4b, 4b', 4b") completely insulate electrically, preferably galvanically, a section of the second surface electrode (10b) from the surrounding second surface electrode (10b), the overlapping sections forming the central region (Z) in an orthogonal projection through one of the main planes of the electrochromic functional element (2).

4. Electrochromic functional element (2) according to one of claims 1 to 3, wherein for electrical contacting the first surface electrode (10a) is connected to first collecting electrodes (5a, 5a', 5a", 5a"') and the second surface electrode (10b) is connected to second collecting electrodes (5b, 5b', 5b", 5b"') are electrically conductively, preferably galvanically, connected, wherein the first collecting electrodes (5a, 5a', 5a", 5a"') and the second collecting electrodes (5b, 5b', 5b", 5b"') are preferably arranged on opposite sides of the electrochromic functional element (2).

5. Electrochromic functional element (2) according to one of claims 1 to 4, wherein the coating-free separating lines (4a, 4a') in the first surface electrode (10a) and the coating-free separating lines (4b, 4b') in the second surface electrode (10b) in the central region (Z) are arranged substantially congruent with one another with respect to the orthogonal projection through a main plane of the electrochromic functional element (2).

6. Electrochromic functional element (2) according to one of claims 1 to 5, wherein a third bus bar (5c) is arranged between the first separating line (4b) and the fourth separating line (4b") of the second surface electrode (10b), on the side of the electrochromic functional element (2) opposite the first bus bars (5a, 5a', 5a", 5a'") and is electrically, preferably galvanically, connected to the first surface electrode (10a), and a fourth bus bar (5d) is arranged between the first separating line (4a) and the fourth separating line (4a") of the first surface electrode (10a), on the side of the electrochromic functional element (2) opposite the second bus bars (5b, 5b', 5b", 5b'") and is electrically, preferably galvanically, connected to the second surface electrode (10b).

7. Glazing (1) with an electrochromic functional element (2), preferably a composite pane (T) or an insulating glazing, comprising a first pane (1a), and an electrochromic functional element (2) according to one of claims 1 to 6, which is connected to the first pane (1a) in a planar manner, preferably via a thermoplastic intermediate layer (3, 3a) or an optically transparent adhesive or by direct deposition on the first pane (1a), for example by thin-film deposition processes.

8. Composite pane (T) with an electrochromic functional element (2), wherein a first pane (1a) is connected via at least one first thermoplastic intermediate layer (3a) with an electrochromic functional element (2) according to one of claims 1 to 6 and the electrochromic functional element (2) is connected via at least one second thermoplastic intermediate layer (3, 3a, 3b) with a second pane (1b) are connected over a large area, preferably by lamination.

9. Insulating glazing with an electrochromic functional element (2), wherein a first pane (1a) is connected to an electrochromic functional element (2) according to one of claims 1 to 6 via at least one first thermoplastic intermediate layer (3a) and at least one second pane (1b) is connected to the first pane (1a) via a frame-shaped spacer.

10. Method for controlling an electrochromic functional element (2) according to one of claims 1 to 6, a glazing (1) according to claim 7, a composite pane (1') according to claim 8 or an insulating glazing according to claim 9, wherein A) a first control voltage (U_Z) is applied by a control unit (11) to the central region (Z) of the electrochromic functional element (2) at least until a first measuring voltage (Sense_Z) is reached; B) a second control voltage (U_P) is applied by the control unit (11) to the surrounding areas (P, P', P", P"') of the electrochromic functional element (2) at least until a second measuring voltage (Sense_P) is reached, wherein the first control voltage (U_Z) is selected to be greater than the second control voltage (U_P).

11. The method according to claim 10, wherein steps A) and B) are carried out repeatedly, preferably at a frequency of 0.01 Hz to 1 kHz, particularly preferably from 1 Hz to 100 Hz.

12. The method according to claim 10 or claim 11, wherein the first measuring voltage (Sense_Z) and the second measuring voltage (Sense_P) are selected to be equal to the maximum operating voltage of the electrochromic functional unit (2).

13. Glazing unit (100) with electrochromic functional element (2), comprising • an electrochromic functional element (2) according to one of claims 1 to 6, a glazing (1) according to claim 7, a composite pane (T) according to claim 8 or an insulating glazing according to claim 9; and • a control unit (11) for electrically controlling the optical properties of the electrochromic functional element (2), wherein the control unit (11) is provided to carry out the method according to one of claims 10 to 12.

14. Glazing unit (100) according to claim 13, wherein the control unit (11) is provided for determining a temperature T of the electrochromic functional element (2), preferably via a temperature sensor, via an electrical resistance of the surface electrodes (10a, 10b) or via the impedance of the electrochromic functional element (2) and as a function of the temperature T for determining the first electrical control voltage (U_Z) and / or the second electrical control voltage (U_P).

15. Use of an electrochromic functional element (2) according to one of claims 1 to 6, a glazing (1) according to claim 7, a composite pane (T) according to Claim 8, an insulating glazing according to Claim 9 or a glazing unit (100) according to Claim 13 or Claim 14 in means of transport for traffic on land, in the air or on water, in particular in motor vehicles, for example as a windscreen, rear window, side window and / or roof window and as architectural or facade glazing, as a functional Individual pieces and as built-in components in furniture, appliances and buildings.

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