Glass unit with electrically controllable optical properties with multiple independent switching zones

Abstract

The invention relates to a glass unit with electrically controllable optical properties with a plurality of independent switching regions (S1, S2, S3, S4), comprising a composite pane with electrically controllable functional elements (4) and a control unit (10) which is adapted to control the optical properties of the functional elements (4). The functional elements (4) have an active layer (5) with electrically controllable optical properties between a first planar electrode (8) and a second planar electrode (9). The first planar electrode (8) is divided into at least two separate electrode sections (8.1, 8.2, 8.3, 8.4) by at least one insulating line (8'), wherein a voltage can be applied between each electrode section (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and the second planar electrode (9) independently of one another in order to control the optical properties of the section of the active layer (5) located therebetween. The second planar electrode (9) is not segmented or segmented to a lesser extent than the first planar electrode (8). According to the invention, the control unit (10) is adapted to determine the temperature of the composite pane and to apply a voltage between the electrode sections (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) on the one hand and the second planar electrode (9) on the other hand, the value of which is related to the temperature of the composite pane.

Description

Technical Field

[0001] The present invention relates to a glass unit having electrically controllable optical properties, its use, and a method for controlling said glass unit. Background Technology

[0002] Glass units with electrically controllable optical properties are known. These glass units comprise a composite plate equipped with functional elements whose optical properties can be altered by an applied voltage. A voltage is applied by a control unit connected to two planar electrodes of the functional element, with an active layer of the functional element located between the planar electrodes. An example of such a functional element is an SPD (suspended particle device), known for example from EP 0876608 B1 and WO 2011033313 A1. The transmission of visible light through the SPD functional element can be controlled by the applied voltage. Another example is a PDLC (polymer dispersed liquid crystal) functional element, known for example from DE102008026339 A1. Here, the active layer comprises liquid crystal embedded in a polymer matrix. Without an applied voltage, the liquid crystal aligns in a disordered manner, resulting in strong scattering of light through the active layer. When a voltage is applied to the planar electrodes, the liquid crystals align in a common direction, and the transmission of light through the active layer is increased. PDLC functional elements function by reducing the total transmittance through increased scattering, thereby preventing free-viewing or ensuring anti-glare. Furthermore, electrochromic functional elements are known, for example, from US 20120026573 A1, WO 2010147494 A1, EP1862849 A1, and WO 2012007334 A1, in which a change in transmission occurs due to an electrochemical process induced by the applied voltage.

[0003] Such a glass unit can be used, for example, as a vehicle dashboard, the light transmission characteristics of which can then be electrically controlled. For instance, the glass unit can be used as a sunroof panel to reduce solar radiation or minimize disruptive reflections. Such sunroof panels are known, for example, from DE 10043141 A1 and EP 3456913 A1. Similarly, windshields are proposed, wherein electrically controllable sun visors are implemented by switchable functional elements to replace conventional mechanically foldable sun visors in motor vehicles. Windshields with electrically controllable sun visors are known, for example, from DE 102013001334 A1, DE 102005049081 B3, DE102005007427 A1, and DE 102007027296 A1.

[0004] It is also known that such a glass unit or switchable functional element is equipped with multiple switching regions, the optical properties of which can be switched independently of each other. Thus, one region of the functional element can be selectively darkened or equipped with high light scattering, while other regions remain transparent. For example, a glass unit with independent switching regions and a method for manufacturing said glass unit are known from WO 2014072137 A1. Furthermore, reference should be made to WO 2017157626A1.

[0005] Independent switching regions are typically constructed such that one planar electrode is divided into separate regions (segments) by insulating wires, each region being independently connected to the control unit and thus independently operable, while the other planar electrode lacks insulating wires. The insulating wires are typically introduced into the planar electrodes via laser processing. Because the planar electrodes must be transparent to ensure visibility through the composite plate, they cannot be selected based on optimal conductivity. Typically, an ITO layer with low conductivity or high resistance is used as the planar electrode. This leads to a problem when only some of the switching regions are voltaged. This voltage causes current to flow through the active layer in each switching region, and this current flow (Stromfluss) causes a potential displacement of the non-segmented planar electrode due to its resistance. This effect is also known as "ground shift." Consequently, a certain voltage is now generated in those switching regions that should not actually be switched, thus altering their optical properties to some extent, which is undesirable. This effect is also known as crosstalk between switching regions. Because switching regions that should not be activated and therefore should be voltage-free are typically switched to the connection potential (reference potential, "ground") of the non-segmented planar electrodes, in order to ensure rapid discharge of each segment when it is off and to avoid the effects of so-called "dirt resistance" (undesired electrical connections due to dust or moisture), crosstalk occurs primarily as interference. This creates a closed current loop through all switching regions.

[0006] In principle, it would be possible to avoid "crosstalk" by segmenting the second planar electrode according to the switching region using insulating wires. However, if the two planar electrodes should be segmented in one processing step, this requires strong laser radiation, which, for example, reduces the aesthetic appearance of the composite board due to combustion effects. Alternatively, if the two planar electrodes are segmented separately, it is difficult to ensure that the insulating wires of the two planar electrodes are precisely overlapped. Furthermore, even if the "double" insulating wires in the two planar electrodes are perfectly overlapped, the "double" insulating wires in the two planar electrodes are always more visually noticeable than the insulating wires in a single planar electrode.

[0007] WO 2019011891 A1 discloses a glass unit with electrically controllable optical properties, wherein the temperature of the composite plate is determined and the voltage applied to the planar electrodes of the electrically controllable functional element is selected according to the temperature. This should resist damage to the functional element due to localized overheating. The functional element can optionally be segmented into multiple independent switching regions, and WO 2019011891 A1 suggests dividing the two planar electrodes into electrode segments by insulating wires. In this case, the problem of "crosstalk" does not occur.

[0008] As is known from US 2014300945 A1, the temperature of a window panel can be determined by measuring the impedance of the active layer of the electrochromic functional element. Summary of the Invention

[0009] Therefore, there is a need for an improved glass unit with electrically controllable optical properties having multiple independent switching regions, wherein the effects of "crosstalk" between active and inactive switching regions are avoided or at least significantly reduced. The objective of this invention is to provide such an improved glass unit and a method for controlling said glass unit.

[0010] According to the invention, this task is accomplished by a glass unit having electrically controllable optical properties and having multiple independent switching regions, the glass unit comprising a composite plate and a control unit. The composite plate comprises an outer plate and an inner plate interconnected via a thermoplastic interlayer, and an electrically controllable functional element disposed between the outer plate and the inner plate. The functional element has an active layer having electrically controllable optical properties between a first planar electrode and a second planar electrode. The control unit is adapted to control the optical properties of the functional element. The first planar electrode is divided into at least two separate electrode segments by at least one insulating wire. Each electrode segment of the first planar electrode and the second planar electrode are electrically connected to the control unit such that a voltage can be applied independently between each electrode segment of the first planar electrode and the second planar electrode to control the optical properties of the section of the active layer located therebetween.

[0011] According to the present invention, the control unit is adapted to determine the temperature of the composite plate and apply a voltage between an electrode segment of a first planar electrode on one side and a second planar electrode on the other side, the value of which is related to the temperature of the composite plate.

[0012] This task is further solved by a method for controlling a glass unit with electrically controllable optical properties having multiple independent switching regions according to the invention. The method according to the invention is characterized by determining the temperature of the composite plate and applying a voltage, the value of which is related to the determined temperature, between at least one electrode segment of a first planar electrode on one side and a second planar electrode on the other side, by means of a control unit.

[0013] The glass unit and the method are described together below, wherein the explanation and preferred design schemes also relate to the glass unit and the method. If preferred features are described in conjunction with the method, it is deduced that the glass unit is also preferably designed and applied accordingly. Conversely, if preferred features are described in conjunction with the glass unit, it is deduced that the method is also preferably performed accordingly.

[0014] The present invention is based on the understanding that the switching characteristics of typical electrically switchable functional elements are temperature-dependent. Higher temperatures result in a stronger change in optical properties from a given voltage applied to the planar electrodes. On the one hand, this has the consequence that the interfering effect of "crosstalk" is more pronounced at higher temperatures because the voltage in the switching region, which should actually be voltage-free, caused by "ground drift," leads to a stronger change in optical properties, i.e., a more pronounced switching state. However, on the other hand, lower voltages are also required at higher temperatures to achieve the desired switching state in the switching region. If the temperature of the composite board is considered when determining the voltage to be applied, the desired switching state is accurately set, and interfering "crosstalk" (i.e., unintentional switching in regions that should actually be voltage-free) is minimized, especially by selecting a voltage that is just high enough to achieve the desired switching state at a given temperature. This is a major advantage of the present invention.

[0015] The composite panel according to the invention comprises at least one outer panel and an inner panel, which are interconnected via a thermoplastic interlayer. The composite panel is configured to separate interior space from the external environment in window openings (particularly vehicle window openings, but alternatively building or room window openings). In the context of the invention, the panel facing the interior space is referred to as the inner panel. The panel facing the external environment is referred to as the outer panel. The outer panel and the inner panel each have an outer surface and an interior space side surface, and a surrounding side surface extending therebetween. In the context of the invention, the outer surface is referred to as the main surface configured to face the external environment in the installation position. In the context of the invention, the interior space side surface is referred to as the main surface configured to face the interior space in the installation position. The interior space side surface of the outer panel and the outer surface of the inner panel face each other and are interconnected via a thermoplastic interlayer.

[0016] The composite panel according to the invention comprises functional elements having electrically controllable optical properties, said functional elements being disposed between an outer panel and an inner panel, i.e., embedded in an intermediate layer. The functional elements are preferably disposed between at least two layers of thermoplastic material in the intermediate layer, wherein said functional elements are connected to the outer panel via a first layer and to the inner panel via a second layer. Alternatively, however, the functional elements may be disposed directly on the surface of the outer or inner panel facing the intermediate layer. The sides of the functional elements are preferably completely surrounded by the intermediate layer, such that the functional elements do not extend to the sides of the composite panel and therefore do not come into contact with the surrounding atmosphere.

[0017] The functional element includes at least one active layer and two planar electrodes disposed on either side of the active layer, such that the active layer is disposed between the planar electrodes. The planar electrodes and the active layer are typically arranged substantially parallel to the surfaces of the outer and inner plates. The active layer has variable optical properties, which can be controlled by a voltage applied to the active layer via the planar electrodes. In the context of this invention, electrically controllable optical properties are understood in particular as properties that can be continuously controlled. Here, in the context of this invention, the switching state of the functional element is represented by the degree to which the optical properties are changed compared to the no-voltage state. A 0% switching state corresponds to the no-voltage state, and a 100% switching state corresponds to the maximum change in optical properties. By appropriately selecting the voltage, all switching states can be continuously achieved therebetween. A 20% switching state, for example, corresponds to a 20% change in optical properties, representing the maximum change. The aforementioned optical properties relate in particular to light transmission and / or scattering characteristics.

[0018] However, it is also conceivable in principle that electrically controllable optical properties can only be switched between two discrete states. Thus, there are only two switching states: 0% and 100%. Similarly, it is conceivable that electrically controllable optical properties can be switched between more than two discrete states.

[0019] The planar electrode is preferably transparent, which in the sense of the invention means that the planar electrode has a light transmittance of at least 50%, preferably at least 70%, and particularly preferably at least 80% in the visible spectrum. The planar electrode preferably comprises at least one metal, metal alloy, or transparent conducting oxide (TCO). The planar electrode can be constructed, for example, based on 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, preferably based on silver or ITO. The planar electrode preferably has a thickness of 10 nm to 2 μm, particularly preferably 20 nm to 1 μm, and very preferably 30 nm to 500 nm.

[0020] According to the invention, the first planar electrode has at least two segments (electrode segments) separated from each other by insulating lines. An insulating line is understood as a linear region in which the material of the planar electrode is absent, such that adjacent segments are materially separated from each other and therefore electrically insulated from each other. This means that there is no direct electrical connection between the electrode segments, although the electrode segments may be indirectly electrically connected to each other to some extent via an active layer in contact with them. The first planar electrode can be divided into multiple segments by multiple insulating lines. Each electrode segment forms a switching region of the glass device. The number of electrode segments can be freely selected by those skilled in the art according to the requirements of individual cases. In a preferred design, the insulating lines extend substantially parallel to each other and from one side of the planar electrode to the opposite side. However, any other geometry is conceivable.

[0021] The insulating wires have a width, for example, from 5 μm to 500 μm, particularly from 20 μm to 200 μm. Preferably, the insulating wires are introduced into the planar electrode by means of laser radiation. The width of the segments, i.e., the distance between adjacent insulating wires, can be appropriately selected by those skilled in the art according to the requirements of individual cases.

[0022] The second planar electrode and the active layer preferably constitute a continuous, complete layer, which is not segmented by insulating wires. However, it is also conceivable in principle that the second planar electrode is segmented to a lesser extent than the first planar electrode, i.e., having fewer insulating wires and electrode segments, such that at least one electrode segment of the second planar electrode is assigned to multiple electrode segments of the first planar electrode. In this case, the problem of "crosstalk" also arises, which can be reduced by the method according to the invention. Each insulating wire of the second planar electrode is arranged overlapping the insulating wire of the first planar electrode in the perspective direction through the composite plate.

[0023] The electrode segments of the first planar electrode are independently electrically connected to the control unit, such that a first potential (time-variable in the case of AC voltage) (independent of the other electrode segments) can be applied to each electrode segment; this first potential is referred to as the switching potential in the context of this invention. The second planar electrode is also electrically connected to the control unit, such that a second potential can be applied to the second planar electrode overall; this second potential is referred to as the reference potential (“Ground”) in the context of this invention. If the first and second potentials are the same, no voltage is applied between the electrodes in their respective switching regions (switching state 0%). If the first and second potentials are different, a voltage is applied between the electrodes in their respective switching regions, thereby producing the final switching state.

[0024] In one variant of the invention, the second planar electrode is also segmented, however to a lesser extent than the first planar electrode, such that at least one electrode segment of the second planar electrode is assigned to multiple electrode segments of the first planar electrode. In this case, the electrode segments of the second planar electrode are also electrically connected to the control unit independently of each other, allowing a second potential (reference potential, "ground") to be applied (independent of the other electrode segments) to each electrode segment. However, at least one electrode segment of the second planar electrode provides a reference potential for multiple switching regions. The relevant switching regions can be controlled independently of each other such that switching potentials can be applied independently to the electrode segments of the first planar electrode, while a single reference potential is applied collectively to the assigned electrode segments of the second planar electrode.

[0025] A control unit is configured and adapted to control the optical characteristics of the functional element. The control unit is electrically connected on one side to the planar electrode of the functional element and on the other side to a power source. The control unit contains the necessary electrical and / or electronic components to apply the required voltage to the planar electrode according to the switching state. Here, the switching state can be pre-given by the user (e.g., via an operating switch, button, or rotary or sliding adjuster), determined by a sensor, and / or transmitted via a digital interface of the vehicle's central control unit (typically a LIN or CAN bus if the composite board is a vehicle board). If the composite board is a vehicle board, the switch, button, rotary, or sliding adjuster can be integrated, for example, into an accessory of the vehicle. However, contact switching surfaces, such as capacitive or resistive switching surfaces, can also be directly integrated into the composite board. Alternatively, the functional element can also be controlled by a contactless method, such as by recognizing gestures or based on the state of the pupil or eyelid determined by a camera and suitable evaluation electronics. The control unit may include, for example, an electronic processor, transformer, transistor, and other components.

[0026] The voltage applied to the planar electrode is preferably an alternating current (AC) voltage. In a preferred design, the power source is a direct current (DC) power source that provides a DC voltage and supplies it to the control unit. This occurs, for example, in a vehicle if the composite board is a vehicle board connected to an onboard voltage. Here, the control unit is preferably connected to the onboard electrical system, from which it obtains voltage and optionally information about the switching state. The control unit is then equipped with at least one inverter to convert the DC voltage to an AC voltage. In a first design, the control unit has a single inverter. To individually operate the electrode segments of the first planar electrode, the inverter's output pole has multiple independent output terminals, with each electrode segment connected to one of these output terminals. Thus, the inverter's output terminals are assigned to each switching region and connected to the corresponding electrode segment of the first planar electrode. Each output terminal is typically implemented via a switch, where the inverter generates a voltage that is subsequently switched. These switches can be directly integrated into the inverter. However, alternatively, the inverter itself may have only a single output terminal, to which an external switch is connected to distribute voltage across the switching regions. In the context of this invention, this externally connected switch is also considered an output terminal of the inverter. The second planar electrode is also connected to the inverter. In the second design, the control unit has multiple inverters, each electrode segment connected to its own inverter for individually controlling the electrode segment of the first planar electrode. Therefore, an inverter is assigned to each switching region, and said inverter is connected to the corresponding electrode segment of the first planar electrode. The first design has the advantages of being less expensive and more space-efficient. However, the first design has the disadvantage that the switching regions can only be digitally switched between a 0% switching state and a final switching state, the final switching state corresponding to the exact output voltage applied by the inverter. Different final switching states (which can be described as independently "dimmable") cannot be provided to the switching regions, which is possible without issue in the second design.

[0027] The one or more inverters can be operated to generate a real AC voltage (including its negative component). This is possible not only for cases where only a single inverter with an independent output exists, but also for cases where each switching region is assigned its own inverter. However, this solution is technically complex because negative potentials are not available in the case of DC power supplies, such as in vehicles. Alternatively, it is possible and often preferred to simulate AC voltages. Here, the control unit is equipped with multiple inverters, where each electrode segment of the first planar electrode is connected to a separate inverter, and the second planar electrode is connected to another inverter. Thus, each electrode segment of the first planar electrode and the second planar electrode are assigned their own inverters. The potentials of the inverters are modulated with a variable function, such as a sine function, where the potentials of the inverters of the electrode segments of the first planar electrode are in phase, and the potentials of the inverters of the second planar electrode are phase-shifted relative to this, particularly by a 180° phase shift. The signal for the second planar electrode is then out of phase relative to the signal for the first planar electrode. This results in a time-varying periodic potential difference with alternating relatively positive and relatively negative values, which corresponds to alternating current voltage.

[0028] Since the onboard voltage of a vehicle (e.g., 12 to 14 V) is typically insufficient to fully switch functional elements, the control unit is preferably also equipped with a DC transformer suitable for increasing the supplied feed voltage (primary voltage), i.e., converting it to a higher secondary voltage (e.g., 65 V). The application of the DC transformer is not limited to the situation in vehicles, but may be necessary or advantageous in other situations. The control unit is connected to a DC power supply and is supplied with a primary voltage by the DC power supply. The primary voltage is converted to a higher secondary voltage by the DC transformer. The secondary voltage is converted to an AC voltage (e.g., 48 V) by an inverter, for which the inverter is suitable. The AC voltage is then applied on one side to the electrode segment of the first planar electrode and on the other side to the second planar electrode.

[0029] In a favorable design, the secondary voltage is 5 V to 70 V, and the AC voltage is 5 V to 50 V.

[0030] The functional elements are preferably operated by the control unit such that in those switching regions where a 0% switching state should be present, the electrode segments of the first planar electrode are equipped with a potential corresponding to the nominal potential of the second planar electrode. Undesirable crosstalk occurs due to the described potential displacement (“ground drift”) of the second planar electrode. In this type of circuit, all switching regions form a closed loop with all electrode segments of the first planar electrode and the second planar electrode participating. The circuit is advantageous in terms of fast switching characteristics due to the rapid discharge of each switching region. Furthermore, the interfering effects of so-called “dirt resistance” (undesirable electrical connections due to dust or moisture) are avoided.

[0031] According to the invention, the temperature of the composite plate is determined such that the voltage to be applied is adapted to that temperature. It is assumed here that the composite plate has a uniform temperature overall, i.e., the temperature of the functional elements is consistent with the temperature of other areas of the composite plate, which is typically, at least approximately, the case. The determination of the temperature of the composite plate therefore corresponds at least approximately to the determination of the temperature of the functional elements.

[0032] In an advantageous design, the composite panel is equipped with a temperature sensor. The temperature sensor is connected to a control unit, allowing the control unit to determine the temperature of the composite panel using the sensor. The measurement signal from the temperature sensor is thus transmitted to and evaluated by the control unit, enabling the control unit to determine the temperature of the composite panel using the temperature sensor. The temperature sensor can be integrated into the composite panel, such that it is embedded in an intermediate layer. Alternatively, the temperature sensor can be externally fastened to the composite panel or distributed within the composite panel. Here, the temperature sensor is preferably fastened to the inner space side surface of the inner panel. The temperature sensor can also be arranged in the control unit itself or in a fastening element, which the control unit uses to fasten it to the composite panel. In principle, a temperature sensor can also be used that is not directly fastened to or integrated into the composite panel, but rather measures the temperature remotely, for example, using an IR sensor positioned in the environment of the composite panel and aligned with the composite panel.

[0033] In another advantageous design, the control unit is suited to determine the impedance of the active layer and, from there, the temperature of the composite plate, more precisely, the temperature of the functional elements. This is possible because impedance (the equivalent of classical ohmic resistance in the case of AC voltage) is temperature-dependent. In particular, there is an injective relationship between the real part of the impedance and the temperature of the functional elements. In this way, a temperature can be assigned to each impedance. In particular, the real part of the impedance decreases strictly monotonically as a function of temperature. This design has the advantage that a temperature sensor is not required, which must be integrated as another component, thus complicating the structure and increasing production costs. The method is implemented such that the control unit determines the impedance of the active layer and, from there, determines or estimates the temperature of the composite plate. For this purpose, in particular, a voltage is applied and the resulting current flow is determined. Impedance can be calculated as the quotient of voltage and current. Calibration data, such as calibration curves or tables, is stored in the control unit, which describes the temperature dependence of the impedance (more precisely, the real part of the impedance) (impedance as a function of temperature or temperature as a function of impedance). The control unit can approximate the temperature by comparing the measured impedance value with the calibration data.

[0034] Different implementations are possible when determining impedance, especially in the measurement of power consumption. If the control unit includes at least one inverter that converts the incoming DC voltage into the outgoing AC voltage, the inverter's output current can be measured. The problem here is that the current thus determined ("apparent current" or "total current") consists of two components: reactive current (figuratively speaking, caused by the "reciprocating movement" of electrons due to AC voltage and capacitance in the functional elements) and active current (caused by parasitic losses in the leads and functional elements). However, only the active current is decisive for determining impedance (more precisely, its real part). Therefore, the active component (active current) of the measured current must be calculated from the total current by the control unit, for example, by determining the phase shift between the voltage and the apparent current.

[0035] Alternatively, in a particularly preferred variant, the impedance can be determined from measurements of the inverter's current consumption. A control unit is suited for this determination. Since only DC voltage exists here, the reactive current disappears over time, provided that each reactive current was not originally intercepted by the intermediate circuit capacitors in the inverter. Taking into account the loss factors in the inverter, the measured current can be directly used as a basis for determining the impedance. Another advantage is that such current measurements for fault identification (short circuits and overloads) are often already present and do not require additional component costs.

[0036] If the control unit is equipped with an inverter that converts a DC voltage (directly or indirectly) supplied by a DC power supply into an AC voltage, then the possibilities described above for determining the impedance and, consequently the temperature, by measuring the output current or, preferably, the current consumption of the inverter, are always applicable. The converted DC voltage (the inverter's input signal) can be a primary voltage supplied by a DC power supply (direct conversion). However, the converted DC voltage can also be a (especially higher) secondary voltage, which has previously been converted to the secondary voltage by a DC transformer (indirect conversion).

[0037] If the temperature of the composite board or functional element is known, the voltage (especially AC voltage) required to achieve a specific switching state can be determined by the control unit. In particular, the higher the temperature, the lower the voltage required. For this purpose, calibration data, such as calibration curves or tables, is stored in the control unit, containing voltage values ​​as a function of both temperature and switching state. Therefore, the required voltage value can be determined by the control unit based on the desired switching state (e.g., 50%) and the determined temperature (e.g., 60°C) and applied to the planar electrodes of the respective switching regions.

[0038] The calibration data is preferably present as a continuous calibration curve, such that voltage values ​​are assigned to each pair of values ​​consisting of temperature and switching state. For example, a calibration curve can be created such that the individual points are known by measurement, and interpolation is performed between said points (e.g., linearly). However, it is also possible, in principle, that the calibration data is present in a tabular format, where a common voltage value is assigned to a specific range of temperature. A common voltage value is less preferred because abrupt changes in switching characteristics may occur when transitioning from one temperature range to another, which is annoying to the user.

[0039] Typically, the temperature dependence of switching characteristics is strong above a certain limiting temperature, while the temperature-dependent changes are relatively small below the limiting temperature. In the case of commonly used functional elements, the limiting temperature is typically around 60°C. Higher temperatures occur, especially under strong solar radiation. Therefore, in an improvement of the invention, the method may be implemented such that a temperature is determined, and for temperatures below a predetermined limiting temperature (e.g., 50°C or 60°C), a temperature-independent voltage is applied to the planar electrode, while for temperatures above the limiting temperature, a temperature-dependent voltage according to the invention is applied.

[0040] In a preferred design, the functional element is a PDLC (polymer-dispersed liquid crystal) functional element. The active layer of the PDLC functional element contains liquid crystal embedded in a polymer matrix. If no voltage is applied to the planar electrodes, the liquid crystal aligns in a disordered manner, resulting in strong scattering of light through the active layer. If a voltage is applied to the planar electrodes, the liquid crystal aligns in a common direction, and the transmission of light through the active layer is increased. However, other functional elements whose optical properties are variable based on liquid crystals can also be used, such as PNLC (polymer-networked liquid crystal) functional elements.

[0041] In another preferred design, the functional element is an SPD (suspended particle device). Here, the active layer contains suspended particles, wherein the absorption of light through the active layer can be altered by applying a voltage to the planar electrodes.

[0042] In another preferred design, the active layer of the functional element is an electrochemically active layer. Such a functional element is called an electrochromic functional element. The transmission of visible light is related to the degree of ion embedding in the active layer, where ions are provided, for example, by an ion storage layer between the active layer and the planar electrode. Transmission can be affected by a voltage applied to the planar electrode, which induces ion migration. Suitable functional layers, for example, contain at least tungsten oxide or vanadium oxide.

[0043] The adjustable functional elements mentioned and their operation are known to those skilled in the art, and therefore a detailed description is not necessary at this point.

[0044] In an advantageous design, the functional element comprises two carrier films in addition to the active layer and the planar electrode, wherein the active layer and the planar electrode are preferably arranged between the carrier films. The carrier films are preferably constructed of thermoplastic materials, such as those based on polyethylene terephthalate (PET), polypropylene, polyvinyl chloride, fluorinated ethylene-propylene, polyvinyl fluoride, or ethylene-tetrafluoroethylene, particularly preferably based on PET. The thickness of the carrier films is preferably from 10 μm to 200 μm. Such functional elements can advantageously be provided as multilayer films, especially in a commercially available manner, cut to the desired size and shape and then laminated into a composite board, preferably laminated with the outer and inner boards respectively via thermoplastic connecting layers. It is possible that even if the first planar electrode is embedded in such a multilayer film, it can be segmented by laser radiation. Laser processing can produce fine, visually inconspicuous insulating lines without damaging the carrier film typically located above them.

[0045] The sides of the functional element can be sealed, for example, by a melt carrier layer or by a (preferably polymer) tape. This protects the active layer, and in particular prevents components of the intermediate layer (especially plasticizers) from diffusing into the active layer, which could lead to the degradation of the functional element.

[0046] For electrical contact with the planar electrodes or electrode segments, these electrodes or segments are preferably connected to so-called flat or thin-film conductors that extend from the intermediate layer beyond the sides of the composite plate. The flat conductors have a strip of metal as a conductive core, typically surrounded by a polymer insulating sheath except for the contact surfaces. Alternatively, so-called bus bars, strips of conductive films (e.g., copper films), or conductive embossed patterns can be arranged on the planar electrodes, with the flat or thin-film conductors connected to these bus bars. The flat or thin-film conductors are connected directly or via other conductors to the control unit.

[0047] In an advantageous design, the control unit is secured to the inner panel's interior space side surface, away from the intermediate layer. The control unit can be, for example, directly adhered to the surface of the inner panel. In another advantageous design, the control unit is inserted into a fastening element, which in turn is secured to the interior space side surface of the inner panel, preferably via an adhesive layer. This fastening element is also known in the vehicle industry as a "bracket" and is typically made of plastic. Electrically connecting the control unit is facilitated by placing it directly on the composite panel. In particular, long cables are not required between the control unit and the functional components.

[0048] However, alternatively, the control unit may not be fixed to the composite panel, but rather integrated, for example, into the vehicle's electrical system, or, if the composite panel is a vehicle body panel, fixed to the vehicle body. The control unit is preferably arranged within the vehicle's interior space, making it invisible, for example, in the dashboard or behind a back panel.

[0049] Composite panels can be equipped with opaque masking prints, particularly in the surrounding edge areas, as is common in the automotive industry, especially for windshields, rear window panels, and sunroof panels. The masking prints are typically made of enamel containing glass frit and pigments, particularly black pigment. The printing ink is typically applied by screen printing and then fired. This masking print is applied to at least one of the panel surfaces, preferably to the interior space side surface of the outer and / or inner panels. The masking prints preferably frame the central transparent area and, particularly, protect the adhesive used to attach the composite panel to the vehicle body via said adhesive. If the control unit is located on the interior space side surface of the inner panel, it is preferably located in the opaque area of ​​the masking print.

[0050] A thermoplastic interlayer is used to connect two panels, as is common in composite panels. Typically, a thermoplastic film is used and the interlayer is constructed from said thermoplastic film. In a preferred design, the interlayer consists of at least a first thermoplastic layer and a second thermoplastic layer, with functional elements arranged between the first and second thermoplastic layers. Thus, the functional elements are connected to the outer panel via a region of the first thermoplastic layer and to the inner panel via a region of the second thermoplastic layer. The thermoplastic layers preferably protrude around the functional elements. Where the thermoplastic layers are in direct contact with each other and are not separated by functional elements, the thermoplastic layers can be melted during lamination so that the original layers become unrecognizable in some cases, and instead, a homogeneous interlayer exists.

[0051] The thermoplastic layer can be constructed, for example, from a single thermoplastic film. The thermoplastic layer can also be composed of segments of different thermoplastic films, with the sides of the segments placed together.

[0052] In a preferred design, the functional element, more specifically, the sides of the functional element, is surrounded by a third thermoplastic layer. The third thermoplastic layer is framed with recesses in which the functional element is placed. The third thermoplastic layer can be formed from a thermoplastic film, into which the recesses have been incorporated by cutting. Alternatively, the third thermoplastic layer can also consist of multiple film segments surrounding the functional element. The intermediate layer is then composed of at least three planarly stacked thermoplastic layers, with the intermediate layer having a recess in which the functional element is disposed. During manufacturing, the third thermoplastic layer is disposed between the first and second thermoplastic layers, wherein the sides of all thermoplastic layers are preferably overlapped. The third thermoplastic layer preferably has approximately the same thickness as the functional element. This compensates for local thickness differences introduced by the positionally constrained functional element, allowing glass breakage to be avoided during lamination and resulting in an improved visual appearance.

[0053] The intermediate layers are preferably constructed from the same material, but in principle they can also be constructed from different materials. The intermediate layer layers or films are preferably based on polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), or polyurethane (PU). This means that the layer or film contains, in majority, the aforementioned materials (greater than 50% by weight) and may optionally contain other components, such as plasticizers, stabilizers, UV or IR absorbers. The thickness of each thermoplastic layer is preferably from 0.2 mm to 2 mm, particularly preferably from 0.3 mm to 1 mm. For example, films with standard thicknesses of 0.38 mm or 0.76 mm can be used.

[0054] The outer and inner panels are preferably made of glass, particularly soda-lime glass, as is common for window panels. However, these panels can also be made of other types of glass, such as quartz, borosilicate, or aluminosilicate glass, or of rigid, clear plastics, such as polycarbonate or polymethyl methacrylate. The panels can be clear or colored or stained. Depending on the application, limits can be set for the degree of coloring or staining: thus sometimes it is necessary to guarantee a specified light transmittance, for example, at least 70% light transmittance in the main perspective area A, according to Regulation 43 of the United Nations Economic Commission for Europe (UN / ECE).

[0055] The outer panel, inner panel, and / or intermediate layer may have suitable coatings known in themselves, such as anti-reflective coatings, anti-stick coatings, anti-scratch coatings, photocatalytic coatings, UV absorbing or reflective coatings, or IR absorbing or reflective coatings, such as sun-protective coatings or low-emissivity coatings.

[0056] The thickness of the outer and inner panels can vary widely and can therefore be adapted to the requirements of individual cases. The outer and inner panels preferably have a thickness of 0.5 mm to 5 mm, and particularly preferably 1 mm to 3 mm.

[0057] The invention further includes the use of glass units according to the invention, and in particular composite panels of glass units according to the invention, in buildings or vehicles used for land, air or water transportation, preferably as window panels of vehicles, especially motor vehicles. For example, glass units can be used as wind deflectors, skylight panels, rear partitions, or side window panels.

[0058] In a particularly preferred design, the glass unit or composite panel serves as a windshield for the vehicle. Here, the functional element is preferably used as an electrically controllable sunshade, arranged in the upper region of the windshield, while the majority of the windshield is unequipped with the functional element. The switching area is preferably arranged substantially parallel to the upper edge of the windshield, with increasing distances from said upper edge. Through the independently switchable switching area, the user can determine the size of the area adjacent to the upper edge based on the solar altitude; this area should be darkened or equipped with high light-scattering properties to avoid glare caused by the sun.

[0059] In another preferred design, the glass unit or composite panel is the sunroof panel of a vehicle. Here, the functional elements are preferably arranged throughout the entire transparent area of ​​the composite panel. In a typical design, the transparent area comprises the entire composite panel minus a surrounding edge region, which is equipped with an opaque shading print on at least one surface of the panel. The functional elements extend throughout the transparent area, with their sides arranged within the area of ​​the opaque shading print and thus invisible to the observer. The switching area is preferably arranged substantially parallel to the front edge of the sunroof panel at an increasing distance from said front edge. With independently switchable switching areas, the user can, for example, specify which areas of the sunroof panel should be transparent and which areas should be darkened or equipped with high light scattering, based on the solar altitude, to avoid excessive heating of the vehicle's interior space. It is also possible to assign a switching area above each vehicle occupant, i.e., the driver, front passenger, and left and right rear passengers. Attached Figure Description

[0060] The invention is described in more detail with reference to the accompanying drawings and embodiments. The drawings are schematic and not to scale. The drawings do not limit the invention in any way. Wherein:

[0061] Figure 1 A top view of one design of the glass unit according to the present invention is shown.

[0062] Figure 2 Showing through Figure 1 The cross-section of the glass unit,

[0063] Figure 3 Show Figure 2 A magnified view of region Z.

[0064] Figure 4 Equivalent circuit diagram shown Figure 1 The functional components of the glass unit,

[0065] Figure 5 Three schematic design schemes of the control unit for the glass unit according to the present invention are shown, and

[0066] Figure 6 A graph showing power consumption is displayed based on the temperature of the electrically controllable functional element 4. Detailed Implementation

[0067] Figure 1 , Figure 2 , Figure 3 and Figure 4 Details of a glass unit with electrically controllable optical properties according to the present invention are shown separately. The glass unit includes a composite panel, which is exemplarily configured as a sunroof panel of a passenger vehicle, the light transmission of which can be electrically controlled region by region. The composite panel includes an outer panel 1 and an inner panel 2, which are interconnected via an intermediate layer 3. The outer panel 1 and the inner panel 2 are composed of soda-lime glass, which may optionally be colored. For example, the outer panel 1 has a thickness of 2.1 mm, and the inner panel 2 has a thickness of 1.6 mm.

[0068] The intermediate layer 3 comprises three thermoplastic layers 3a, 3b, and 3c, each constructed from a 0.38 mm thick PVB thermoplastic film. The first thermoplastic layer 3a is connected to the outer plate 1, and the second thermoplastic layer 3b is connected to the inner plate 2. The third thermoplastic layer 3c, located in between, has a notch into which the functional element 4, with electrically controllable optical properties, fits substantially precisely, i.e., roughly flush on all sides. The third thermoplastic layer 3c thus constitutes a type of passepartout or frame for the approximately 0.4 mm thick functional element 4, which is therefore encapsulated and protected by the thermoplastic material. The functional element 4 is, for example, a PDLC multilayer film that can be switched from a clear transparent state to a cloudy (diffuse) state. The functional element 4 is a multilayer film consisting of an active layer 5 located between two planar electrodes 8 and 9 and two carrier films 6 and 7. The active layer 5 comprises a polymer matrix with liquid crystal dispersed therein, which is aligned according to a voltage applied to the planar electrodes 8 and 9, thereby allowing optical properties to be tuned. The carrier films 6 and 7 are composed of PET and have a thickness of, for example, 0.125 mm. The carrier films 6 and 7 are equipped with a coating made of ITO having a thickness of approximately 100 nm, pointing towards the active layer 5, which forms the planar electrodes 8 and 9. The planar electrodes 8 and 9 are connected to a cable 14 via a bus conductor (not shown, for example, constructed from strips of copper film), which establishes an electrical connection to the control unit 10.

[0069] The control unit 10 is exemplarily positioned on the surface of the inner panel 2 facing away from the interior space of the intermediate layer 3. For this purpose, for example, a fastening element (not shown) is attached to the inner panel 2, and the control unit 10 is inserted into said fastening element. However, the control unit 10 is not necessarily required to be directly mounted on the composite panel. Alternatively, the control unit may be mounted, for example, on the dashboard or vehicle body, or integrated into the vehicle's onboard electrical system.

[0070] The composite panel has a surrounding edge region equipped with an opaque masking print 13. This masking print 13 is typically constructed of black enamel. The masking print is screen-printed as a printing ink containing black pigment and glass frit and then fired into the panel surface. The masking print 13 is exemplarily imprinted on the inner space side surface of the outer panel 1 and also on the inner space side surface of the inner panel 2. The sides of the functional element 4 are covered by this masking print 13. The control unit 10 is arranged in this opaque edge region, i.e., adhered to the masking print 13 on the inner panel 2. There, the control unit 10 does not interfere with the view through the composite panel and is visually inconspicuous. Furthermore, the control unit is positioned at a small distance from the sides of the composite panel, thus requiring only a short cable 14 for electrical connection of the functional element 14.

[0071] On the other hand, the control unit 10 is connected to the vehicle's onboard electrical system, which in Figure 1 and 2 For simplicity, the figures are not shown. The control unit 10 is adapted to apply a voltage to the planar electrodes 8, 9 of the functional element 4 according to a pre-given switching signal, for example, by the driver pressing a button, the voltage being required for the desired optical state (switching state) of the functional element 4.

[0072] The composite panel exemplarily has four independent switching zones S1, S2, S3, and S4, wherein the switching state of the functional element 4 can be adjusted independently of each other by the control unit 10. The switching zones S1, S2, S3, and S4 are arranged sequentially from the front to the rear of the sunroof panel, where the terms front and rear refer to the direction of travel of the vehicle. By using the switching zones S1, S2, S3, and S4, the driver of the vehicle can (e.g., based on the sun's altitude) select to equip only one zone of the composite panel with a diffused state, rather than equipping the entire composite panel, while other zones remain transparent.

[0073] To construct the switching regions S1, S2, S3, and S4, the first planar electrode 8 is interrupted by three insulating lines 8', which are arranged substantially parallel to each other and extend from one side of the functional element 4 to the opposite side. The insulating lines 8' are typically introduced into the first planar electrode 8 by laser processing and divide the first planar electrode into four materially separate electrode segments 8.1, 8.2, 8.3, and 8.4. Each electrode segment 8.1, 8.2, 8.3, and 8.4 is connected to the control unit 10 independently of the other electrode segments. The control unit is adapted to independently apply voltages between each electrode segment 8.1, 8.2, 8.3, and 8.4 of the first planar electrode 8 on one side and the second planar electrode 9 on the other side, thereby applying the required voltage to the section of the active layer 5 located therebetween to achieve the desired switching state.

[0074] like Figure 4 As illustrated in the equivalent circuit diagram, control unit 10 is connected to power supply 15 via the vehicle's onboard electrical system. In the vehicle domain, power supply 15 typically provides a DC voltage in the range of 12 V to 14 V (vehicle onboard voltage). Control unit 10 is equipped with a DC transformer 11 that converts the onboard voltage (primary voltage) into a DC voltage with a higher value, such as 65 V (secondary voltage). The secondary voltage must be high enough to achieve 100% switching of functional element 4. Control unit 10 is further equipped with an inverter 12 that converts the secondary voltage into AC voltage. One pole of inverter 12 is connected to the second planar electrode 9. For the other pole, inverter 12 has multiple independent outputs, each of which is connected to electrode segments 8.1, 8.2, 8.3, and 8.4, each having one of the independent outputs, such that the switching state of the corresponding switching regions S1, S2, S3, and S4 can be adjusted independently of other switching regions.

[0075] In the 0% switching state, electrode segments 8.1, 8.2, 8.3, 8.4 and the second planar electrode 9 always have the same potential, so no voltage is applied. In the switching states greater than 0% in switching regions S1, S2, S3, S4, a voltage is applied between the corresponding electrode segments 8.1, 8.2, 8.3, 8.4 and the second planar electrode 9. Due to the voltage, current flows through the corresponding segment of the active layer 5. Since the ITO layer used as the planar electrodes 8, 9 has a high resistance, this current flow causes a potential shift in the second planar electrode 9. This now causes a certain voltage to be generated in the switching regions S1, S2, S3, S4, which should actually have a 0% voltage-free switching state, resulting in a final switching state greater than 0% in the relevant switching regions, which is actually undesirable. In this case, communication (crosstalk) between switching regions S1, S2, S3, S4 is discussed.

[0076] The effect of crosstalk becomes more pronounced at higher temperatures because, on the one hand, the sensitivity of functional element 4 to small voltages increases, and on the other hand, the conductivity of planar electrodes 8 and 9 decreases (its resistance increases), resulting in a larger voltage drop. Typically, crosstalk is particularly noticeable at temperatures above 60°C. Furthermore, it is readily understood that the more switching regions S1, S2, S3, and S4 are activated—that is, intentionally voltaged to produce the final switching state—the more disruptive the crosstalk becomes, because the current flows through multiple switching regions and is thus stronger, causing a more pronounced potential shift in the second planar electrode 9. Similarly, the higher the switching state of one or more activated switching regions, the more pronounced the crosstalk becomes.

[0077] However, the higher temperature also necessitates a lower voltage to achieve the desired switching state. This effect is fully utilized according to the present invention by applying a voltage to the planar electrodes 8 and 9, the value of which is temperature-dependent. For this purpose, the temperature of the composite plate or functional element 4 is first determined. Based on calibration data, the control unit 10 then determines the voltage required at a given temperature to achieve the user-defined switching state. This voltage is then applied to the relevant switching area. The advantage is that the switching state, less than 100%, can be set very accurately, and since the applied voltage is selected to be minimal for the switching state, the interference effect of "crosstalk" is also minimized. The control unit is equipped with necessary components (not shown), particularly a data storage device for storing calibration data and a processor for performing the necessary calculations and controlling the various outputs of the inverter, using these outputs to manipulate different electrode segments 8.1, 8.2, 8.3, and 8.4.

[0078] To determine the temperature, the composite board can, for example, be equipped with a temperature sensor that transmits the measured temperature to the control unit. If the temperature of the functional element 4 is approximately estimated based on the impedance of the active layer 5, a temperature sensor may not be necessary. The applied voltage causes a current to flow through the active layer 5, the magnitude of which depends on the temperature-dependent impedance. If the current consumption is determined under the applied voltage, the current flow or the impedance of the active layer 5 can be determined, and the temperature can be approximately determined from this. For this purpose, calibration data is stored in the control unit 10, which correlates the impedance of the active layer 5 with the temperature.

[0079] Figure 5 Schematic equivalent circuit diagrams of the control unit 10 connected to the DC power supply 15 are shown with three design options. For simplicity, the connections to the electrode segments 8.1, 8.2, 8.3, 8.4 and to the second planar electrode 9 are symbolically indicated by arrows, and the functional element 4 itself is not shown.

[0080] exist Figure 5 In design scheme a, the control unit 10 has a single inverter 12, which is connected on one side to the second planar electrode 9 and on the other side via separate output terminals to electrode segments 8.1, 8.2, 8.3, and 8.4. This design scheme corresponds to... Figure 4 The design scheme is as follows. The output terminal is typically constructed as a switch, through which signals are distributed to electrode segments 8.1, 8.2, 8.3, and 8.4. As shown in the figure, the switch does not necessarily have to be integrated into the inverter 12, but can also be connected to the inverter as an external component. With a single inverter 12, the control unit is technically simple to construct, low in cost, and space-saving. Therefore, the switching regions S1, S2, S3, and S4 cannot be controlled completely independently of each other. Instead, each switching region S1, S2, S3, and S4 can only be switched between a 0% switching state and a switching state X, where X is the same for all switching regions S1, S2, S3, and S4.

[0081] exist Figure 5 In design scheme b, the control unit 10 has four inverters 12. Each inverter 12 is connected to the second planar electrode 9 on one side and to one of the electrode segments 8.1, 8.2, 8.3, and 8.4 on the other side. Here, the switching regions S1, S2, S3, and S4 can be controlled completely independently of each other, such that, for example, switching region S1 can have a 100% switching state, switching region S2 can have a 50% switching state, and switching regions S3 and S4 can have a 0% switching state.

[0082] exist Figure 5The design schemes a and 5b require that the one or more inverters 12 generate a real AC voltage, including negative components, which is technically quite complex. Figure 5 c illustrates a design scheme that can be described as simulating AC voltage. The control unit 10 has five inverters 12, four of which are connected to one of the electrode segments 8.1, 8.2, 8.3, and 8.4 respectively, and a fifth inverter 12 is connected to the second planar electrode 9. The potential of the inverters 12 is modulated using a variable function, for example, a sine function, wherein the potentials of the inverters 12 assigned to electrode segments 8.1, 8.2, 8.3, and 8.4 are in phase, while the potential of the inverter 12 assigned to the second planar electrode 9 is shifted 180° relative to this. This generates a time-variable periodic potential difference with alternating relatively positive and relatively negative values, corresponding to AC voltage.

[0083] Figure 6 A graph showing power consumption plotted for temperature of exemplary PDLC functional element 4 is presented. Power consumption is used here as a measure of current consumption. Not only apparent power (derived from apparent current) but also active power (derived from active current) is plotted. Apparent power consists of active power and reactive power. It can be seen that apparent power (or apparent current) is not suitable for determining temperature because the temperature-dependent curve of the apparent power does not correspond to a one-to-one function: the same power value (or current value) may appear at more than one temperature. Active power (or active current), on the other hand, is described by a one-to-one function. Therefore, the active power can be well used to determine temperature.

[0084] The apparent current (expressed here as apparent power) is derived from the measurement of the output current of inverter 12. This measurement can also be used to determine the temperature if the reactive current is subsequently calculated from the apparent current to determine the active current. However, it is more advantageous to measure the current consumption of inverter 12. After correcting for the loss current in the inverter, which is to be assumed to be linear, this current consumption directly corresponds to the active current (expressed here as active power).

[0085] Furthermore, it can be seen from the graph that current consumption (expressed here as power consumption) and thus impedance are strongly temperature-dependent only from a specific limiting temperature of approximately 60°C, while temperature-dependent changes are relatively small below this limiting temperature. Therefore, it is conceivable that the method according to the invention is performed such that a temperature is determined, and for temperatures below the predetermined limiting temperature, a temperature-independent voltage is applied to the planar electrodes 8, 9, while for temperatures above the limiting temperature, a temperature-dependent voltage according to the invention is applied. The limiting temperature may, for example, be 40°C, 50°C, or 60°C.

[0086] List of reference numerals

[0087] (S1, S2, S3, S4) Independent switching areas for the glass unit

[0088] (1) Outer panel

[0089] (2) Inner plate

[0090] (3) Thermoplastic interlayer

[0091] (3a) The first layer of intermediate layer 3

[0092] (3b) The second layer of intermediate layer 3

[0093] (3c) The third layer of intermediate layer 3

[0094] (4) Functional elements with electrically controllable optical characteristics

[0095] (5) The active layer of functional element 4

[0096] (6) The first carrier film of functional element 4

[0097] (7) The second carrier film of functional element 4

[0098] (8) The first planar electrode of functional element 4

[0099] (8.1, 8.2, 8.3, 8.4) Electrode segments of the first planar electrode 8

[0100] (8') Insulation wire between the two electrode segments 8.1, 8.2, 8.3, and 8.4

[0101] (9) The second planar electrode of functional element 4

[0102] (10) Control Unit

[0103] (11) DC transformer

[0104] (12) Inverter

[0105] (13) Covering up printed materials

[0106] (14) Cable

[0107] (15) Power supply / DC power supply

[0108] XX' Cutting Line

[0109] Y is the magnified area.

Claims

1. A glass unit with electrically controllable optical properties, the glass unit having multiple independent switching regions (S1, S2, S3, S4), the glass unit comprising... - Composite panel, the composite panel comprising -Outer panel (1) and inner panel (2), the outer panel and the inner panel are connected to each other via a thermoplastic interlayer (3), - Electrically controllable functional element (4), the electrically controllable functional element is arranged between the outer plate (1) and the inner plate (2) and has an active layer (5) with electrically controllable optical properties between the first planar electrode (8) and the second planar electrode (9). - Control unit (10), the control unit being adapted to control the optical characteristics of the functional element (4), The first planar electrode (8) is divided into at least two separate electrode segments (8.1, 8.2, 8.3, 8.4) by at least one insulating wire (8'). Each electrode segment (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and the second planar electrode (9) are electrically connected to the control unit (10), so that a voltage can be applied independently between each electrode segment (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and the second planar electrode (9) to control the optical properties of the section of the active layer (5) located therebetween. The second planar electrode (9) has no insulating wire (8') or has fewer insulating wires (8') than the first planar electrode (8) and therefore fewer electrode segments, such that at least one electrode segment of the second planar electrode (9) is assigned to multiple electrode segments (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8). characterized in that The control unit (10) is adapted to determine the temperature of the composite plate and apply a voltage between the electrode segments (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and the second planar electrode (9) on the other hand, the value of the voltage being related to the temperature of the composite plate, wherein the desired switching state is accurately set on the one hand, and interference "crosstalk" is minimized on the other hand.

2. The glass unit according to claim 1, wherein the functional element (4) is a PDLC functional element, an SPD functional element, or an electrochromic functional element.

3. The glass unit according to claim 1 or 2, wherein the control unit (10) is wherein... - Connect to DC power supply (15), and - Equipped with at least one inverter (12) adapted to convert DC voltage into AC voltage, which is applied on one hand to the electrode segments (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and on the other hand to the second planar electrode (9).

4. The glass unit according to claim 3, wherein the control unit (10) is wherein... - Connect to the DC power supply (15), - is equipped with a DC voltage transformer (11) which is suitable for converting a primary voltage of the DC voltage source (15) into a higher secondary voltage, and - is equipped with at least one inverter (12) which is suitable for converting the secondary voltage into the AC voltage which is applied to the electrode segments (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and to the second planar electrode (9).

5. Glass unit according to claim 1 or 2, wherein the composite pane is equipped with a temperature sensor which is connected with the control unit (10) so that the control unit (10) can determine the temperature of the composite pane by means of the temperature sensor.

6. Glass unit according to claim 1 or 2, wherein the control unit (10) is suitable for determining the impedance of the active layer (5) and from this the temperature of the composite pane.

7. Glass unit according to claim 3, wherein the control unit (10) is suitable for determining the impedance of the active layer (5) and from this the temperature of the composite pane.

8. Glass unit according to claim 7, wherein the control unit (10) is suitable for determining the impedance of the active layer (5) from a measurement of the current consumption of the inverter (12).

9. Glass unit according to claim 1 or 2, wherein the at least one insulating wire (8') has a width of 5 μm to 500 μm.

10. Method for controlling a glass unit with electrically controllable optical properties having a plurality of independent switching regions (S1, S2, S3, S4), wherein the glass unit comprises - a composite pane which comprises - an outer pane (1) and an inner pane (2) which are connected to one another via a thermoplastic intermediate layer (3), - an electrically controllable functional element (4) which is arranged between the outer pane (1) and the inner pane (2) and has an active layer (5) with electrically controllable optical properties between a first planar electrode (8) and a second planar electrode (9), and - a control unit (10) which is suitable for controlling the optical properties of the functional element (4), wherein the first planar electrode (8) is divided into at least two separate electrode segments (8.1, 8.2, 8.3, 8.4) by at least one insulating wire (8'), wherein each electrode segment (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and the second planar electrode (9) are electrically connected with the control unit (10) so that a voltage can be applied between each electrode segment (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and the second planar electrode (9) independently of one another in order to control the optical properties of the section of the active layer (5) located therebetween, wherein the control unit (10) is suitable for determining the impedance of the active layer (5) and from this the temperature of the composite pane. wherein the second planar electrode (9) has no insulation lines (8') or a smaller number of insulation lines (8') and thus a smaller number of electrode segments than the first planar electrode (8), such that at least one electrode segment of the second planar electrode (9) is assigned a plurality of electrode segments (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8), characterized in that (a) the temperature of the composite pane is determined, (b) a voltage is applied between, on the one hand, at least one electrode segment (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and, on the other hand, the second planar electrode (9) by means of the control unit (10), the value of the voltage being related to the determined temperature.

11. The method according to claim 10, wherein the composite pane is equipped with a temperature sensor, which is connected to the control unit (10), and wherein the control unit (10) determines the temperature of the composite pane by means of the temperature sensor.

12. The method according to claim 10, wherein the control unit (10) determines the impedance of the active layer (5) and from this determines the temperature of the composite pane.

13. The method according to claim 12, wherein the control unit (10) is connected to a direct-current voltage source (15) and is equipped with an inverter (12), which converts the direct-current voltage into an alternating-current voltage, which is applied to the electrode segments (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) on the one hand and to the second planar electrode (9) on the other hand, and wherein the control unit (10) determines the impedance of the active layer (5) from a measurement of the current consumption of the inverter (12).

14. The method according to claim 13, wherein the control unit (10) is furthermore equipped with a direct-current voltage transformer (11), which converts a primary voltage of the direct-current voltage source (15) into a higher secondary voltage, wherein the inverter (12) converts the secondary voltage into the alternating-current voltage.

15. The method according to any one of claims 10 to 14, wherein the control unit (10) determines the value of the voltage, which is applied between at least one electrode segment (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and the second planar electrode (9), as a function of temperature and switching state from calibration data.

16. Use of a glass unit according to any one of claims 1 to 9 as a window pane of a vehicle.

17. The use according to claim 16, wherein the glass unit is used as a windshield pane or a sunroof pane.

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