Glazing unit with electrically controllable optical properties and temperature-dependent switching behavior

Abstract

The present invention relates to a glazing unit with electrically controllable optical properties, which comprises: - a laminated pane (100) comprising a functional element (4) with electrically controllable optical properties, and - a control unit (10) electrically connected to the functional element (4), Here, the control unit (10) has a data set or programmed function that assigns a lamp voltage to each temperature within a predefined temperature range, where the control unit (10) is adapted to: - Check the temperature, - selecting the lamp voltage from the data set based on the ascertained temperature or calculating it by a programmed function; and - applying the selected or calculated lamp voltage to the functional element (4).

Description

[Technical Field]

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

[0002] Glazing units with electrically controllable optical properties are known. They comprise laminated panes equipped with a functional element whose optical properties can be changed by applying a voltage. The voltage is applied via a control unit, which is connected to two planar electrodes of the functional element, between which the active layer of the functional element is located. An example of such a functional element is an SPD functional element (suspended particle device), which is known, for example, from EP 0 876 608 A1 and WO 2011 / 033313 A1. By applying a voltage, the transmission of visible light can be controlled by the SPD functional element. Another example is a PDLC functional element (polymer dispersed liquid crystal), which is known, for example, from DE 10 2008 026 339 A1. The active layer contains liquid crystals embedded in a polymer matrix. When no voltage is applied, the liquid crystals will be aligned in a disordered manner. As a result, light passing through the active layer is strongly scattered. When a voltage is applied to the planar electrodes, the liquid crystals will align in a common direction, increasing the light transmittance through the active layer. PDLC functional elements operate primarily by increasing scattering rather than by reducing the total transmittance, thereby preventing clear vision or providing anti-glare protection. Electrochromic functional elements are also known, for example from U.S. Patent Application Publication No. 20120026573, WO 2010 / 147494, EP 1 862 849, and WO 2012 / 007334, in which the change in transmittance is the result of an electrochemical process induced by an applied voltage.

[0003] Such glazing units may be used, for example, as window panes in vehicles, and their light transmission behavior may be electrically controlled. They may also be used, for example, as roof panels to reduce exposure to direct sunlight or problematic reflections. Such roof panels are known, for example, from German Patent Application Publication No. 10043141 and European Patent Application Publication No. 3456913. Windshields have also been proposed in which an electrically controllable sunscreen is realized by a switchable functional element, thereby replacing conventional mechanically foldable sunscreens in automobiles. Windshields with electrically controllable sunscreens are known, for example, from German Patent Application Publication No. 102013001334, German Patent Application Publication No. 102005049081, German Patent Application Publication No. 102005007427, and German Patent Application Publication No. 102007027296.

[0004] It is also known to provide such glazing units or switchable functional elements with multiple segments whose optical properties can be switched independently of one another. For example, one region of the functional element can be selectively darkened or provided with a high level of light scattering, while other regions remain transparent. Glazing units with independent segments and methods for their production are known, for example, from WO 2014 / 072137. Reference is also made to WO 2017 / 157626.

[0005] By applying a voltage to individual segments, the optical properties can be controlled. In this way, the segments can be animated, for example, to darken or switch between opaque and transparent sequentially, randomly in any order, or from the outer segments to the inner segments. However, the optical properties of the functional element are temperature-dependent. For example, at high temperatures, e.g., above 50°C, the electrical resistance of the planar electrodes can increase significantly. When a voltage is applied to a particular segment at high temperatures, this results in the generation of an electric field in the vicinity of the segment that is actually switched off. The segments then change their optical state not through the application of a target voltage, but rather through the electric field.

[0006] Another optical problem occurs when the functional element operates at low temperatures, especially below 0°C. In this case, the switching time of the functional element can increase significantly. While the time between two optical states is typically less than one second, at low temperatures the time can be several minutes before the change from one optical state to another is complete. As a result, an unfamiliar user of the functional element may assume that the functional element is not working properly. One solution to this problem is disclosed in WO 2019 / 111235. A heating coating can be used to heat the functional element when the temperature is too low. However, this solution requires the use of a heating coating that must be electrically activated. Therefore, additional space must be available, and an electrical supply must be ensured. WO 9837453 discloses an electrochromic element in which a temperature-dependent voltage is applied to the electrochromic element, thereby enabling the fastest possible color change. The temperature is determined by a temperature-sensing device, which preferably measures directly within the electrochromic functional element. A temperature dependent voltage is applied to the electrochromic functional element by means of a temperature independent, preferably linear, ramp voltage, thereby achieving a color change of the functional element. Summary of the Invention [Problem to be solved by the invention]

[0007] There is a need for glazing units with improved switching behavior of electrically controllable optical properties. It is an object of the present invention to provide such an improved glazing unit and a method for controlling same. [Means for solving the problem]

[0008] This object is achieved according to the invention by a glazing unit with electrically controllable optical properties, the glazing unit comprising: a laminated pane comprising a functional element with electrically controllable optical properties, and - a control unit electrically connected to the functional element.

[0009] The control unit has a data set or programmed function that assigns a lamp voltage to each temperature within a predefined temperature range. The control unit is also suitable for: - checking the temperature of the functional element; - selecting the lamp voltage from the data set or calculating it by a programmed function based on the ascertained temperature; and Apply a voltage to the functional element with the selected or calculated ramp voltage.

[0010] This object is also achieved by a method for controlling a glazing unit having electrically controllable optical properties, characterized in that the control unit: (a) checking the temperature of the functional element; (b) selecting a lamp voltage from the data set based on the ascertained temperature or calculating it by a programmed function; and (c) Applying a voltage to the functional element at the selected or calculated ramp voltage.

[0011] The glazing unit and the method are described together below, but the explanations and preferred embodiments relate equally to the glazing unit and the method. When preferred features are described in relation to the method, this means that the glazing unit is preferably designed and suitable accordingly. On the other hand, when preferred features are described in relation to the glazing unit, this means that the method is also preferably performed accordingly. The glazing unit is intended to be used in a vehicle or building. The laminated pane is provided to separate the interior space from the exterior environment when the window is opened (particularly when a vehicle window is opened, but alternatively also when a building or room window is opened).

[0012] The present invention is based on the knowledge that the switching behavior of a typical electrically controllable functional element is temperature-dependent. The switching behavior can be adapted to the temperature by determining the temperature and selecting a ramp voltage from a data set or calculating it according to a preprogrammed function. Because the time to change between two switching states is temperature-dependent, depending on the temperature of the functional element, several minutes may pass before the change between the two switching states occurs, but it could also take less than a second. According to the present invention, a voltage is applied to the functional element in stages. The ramp voltage can be calculated or selected by the glazing unit as a function of the temperature of the functional element, thereby accelerating or slowing down the time for the change between the two switching states.

[0013] A "defined temperature range" is a temperature interval that is stored in a data set or that constitutes the starting domain of a programmed function and must be defined before the functional element is used.

[0014] The defined temperature range preferably extends from −30° C. to 120° C., particularly preferably from −25° C. to 100° C., in particular from −20° C. to 100° C. In these temperature ranges, the time required to change between the two switching states varies, in particular at different temperatures. These temperature ranges are also typical temperature ranges that occur in natural environments (i.e., not merely in laboratory or exceptional conditions).

[0015] In the sense of the present invention, "applying a voltage" also means that a change can occur from a switching state in which a voltage is applied by a control unit to a switching state in which there is no voltage. The no-voltage state also refers to a state of equilibrium voltage, for example, in an electrochromic functional element. Therefore, no voltage rather means that no voltage is applied by a voltage source.

[0016] In a preferred embodiment of the present invention, the functional element has at least two switching states with different optical properties, and a temperature-dependent switching time is required for the change between the two switching states. As a result, a time t max There is a temperature within any temperature range where

[0017] Here, each lamp voltage, selected or calculated based on the temperature ascertained by the control unit, is t max The switching time t Switch thereby reducing the switching time t Switch occurs when a voltage is applied to the functional element.

[0018] In other words, the temperature-dependent switching speed v min The control unit determines whether a temperature having v exists within a predetermined temperature range. min A switching speed v Switch In this case, the control unit: (a) checking the temperature of the functional element; (b) Based on the ascertained temperature, select the lamp voltage from the data set or calculate the lamp voltage by a programmed function, thereby determining the switching rate v Switch occurs when a voltage is applied to the functional element; and (c) applying a voltage to the functional element with a ramp voltage, thereby causing a change between at least two switching states; [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a plan view of an embodiment of a glazing unit according to the present invention. [Figure 2] FIG. 2 is a cross-sectional view through the glazing unit of FIG. [Figure 3] FIG. 3 is an enlarged representation of region Z of FIG. [Figure 4] FIG. 4 shows the functional elements of FIG. 1 in a circuit diagram. [Figure 5A] FIG. 5A is a diagram of the "switching on" of a typical electrically controllable functional element at 23° C. according to the switching time; [Figure 5B] FIG. 5B is a diagram of the "switching off" of a typical electrically controllable functional element at 23° C. according to the switching time; [Figure 6A] FIG. 6A is a diagram of the "switching on" of a typical electrically controllable functional element at -20° C. according to switching time. [Figure 6B] FIG. 6B is a diagram of the "switching off" of a typical electrically controllable functional element at -20° C. according to switching time. [Figure 7] FIG. 7 is a representation of the method according to the invention in an animated manner. DETAILED DESCRIPTION OF THE INVENTION

[0020] In the context of the present invention, the expression "any temperature range" preferably means, for each temperature interval considered, at least one temperature, the change between two switching states of which is within a time t under other constant conditions (lamp voltage, pressure, humidity, etc.). max This means that there is at least one temperature that requires t. Therefore, in any temperature range, it does not matter whether we consider temperatures from, for example, -20°C to 50°C or temperatures from 0°C to 100°C. Each of these two temperature ranges has t max "Any temperature range" also means a temperature range spanning at least 1°C, preferably at least 2°C, in particular at least 5°C. Any temperature range therefore has a width of at least 1°C. Thus, a temperature range spanning at least 1°C can be, for example, 150°C to 151°C, or, for example, -51°C to -50°C. It is not limited to the range of 0°C to 1°C.

[0021] "Temperature" ("temperature value") may also mean a non-integer number. Preferably, a temperature (temperature value) within a temperature range may be a real number with up to 10 decimal places, particularly preferably with up to 5 decimal places, and especially with up to 2 decimal places.

[0022] As a function of the temperature of the functional element, the required switching time between two switching states can be from less than a second to several minutes. Such variable switching behavior is undesirable for users of glazing units having such functional elements. Such temperature-dependent switching times of the functional element quickly give a non-expert user the impression that the glazing unit is not working properly. This impression can worsen the user experience. This problem can be solved by the control unit having a data set or a programmed function, and the temperature is ascertained by the control unit. The data set assigns a ramp voltage to each temperature within a predefined temperature range. The programmed function has at least an initial range represented by the defined temperature range and calculates the ramp voltage (or ramp voltage in the final range) depending on the temperature. When changing between two switching states, the voltage required for switching is applied by a ramp voltage selected from the data set or calculated by the programmed function. The ramp voltage is selected depending on the ascertained temperature, whereby the change between the two switching states is accelerated by a switching speed v Switch The time it takes to change from one of the two switching states to the other is t max It goes without saying that the change time between the two switching states corresponds to at least most of the switching operation, i.e., t max For all switching operations which have a switching time less than the technically required one, it is artificially extended.

[0023] In the context of the present invention, an electrically controllable optical property is understood to mean, in particular, such a property that is continuously controllable. In the context of the present invention, the term "switching states through which the functional element can be changed" refers to possible switching states on a scale from a switching state with minimal change in the optical property (0% switching state or minimum switching state) to a switching state with maximal change in the optical property (100% switching state or maximum switching state). All switching states between the aforementioned two states can be continuously realized by appropriately selecting the voltage. A 20% switching state, for example, corresponds to a change by 20% of the maximum change in the optical property. The optical property relates in particular to light transmission and / or scattering behavior. The switching time for changing between switching states can depend on the rate of change in the optical property. The difference in change is preferably directly proportional to the switching time, so that, for example, a change from a 0% switching state to an 80% switching state preferably takes four times as long as a change from a 0% switching state to a 20% switching state. However, the switching time for changing between switching states can also be independent of the rate of change in the optical property.

[0024] However, it is conceivable in principle that the electrically controllable optical property can be switched between only two discrete switching states, in which case there are only two switching states, namely 0% and 100%, and it is also conceivable that the electrically controllable optical property can be switched between more than two discrete switching states.

[0025] An AC voltage (alternating current voltage) or a DC voltage (direct current voltage) is applied to the functional element. If the functional element is a PDLC functional element or an SPD functional element, an AC voltage is applied to the functional element. If the functional element is an electrochromic functional element, a DC voltage is applied to the functional element.

[0026] When the functional element is an electrochromic functional element, the "lamp voltage" in the context of the present invention is expressed in units of Vs -1 This means a linear voltage change over time.

[0027] However, if the functional element is a PDLC or SPD functional element, the ramp voltage will not be linear and will be determined by an inverse function resulting from the optical characteristics of the desired switching state. Because nonlinear coherence exists between the voltage, i.e., the RMS value of the AC voltage, and the optical characteristics of the functional element, an inverse function is used to determine the ramp voltage. The inverse function may, in particular, be an inverse function of the characteristics of the switching state setting of the functional element. In other words, to reach a specific switching state, a voltage (the RMS value of the AC voltage) is applied to the functional element in steps, where the voltage either decreases or increases in each step as a function of the type of functional element and as a function of achieving either a transparent switching state or a relatively less transparent switching state. The voltage step increase is preferably performed nonlinearly by the inverse function. The inverse function is temperature-dependent, so that if the ramp voltage is nonlinear, the ramp voltage will preferably be part of the program function. Alternatively, all voltage values ​​applied in steps up to the final voltage are stored in a data set for all temperatures within a defined temperature range. Each voltage change occurs within a specific time period, preferably up to 1 second.

[0028] The programmed function includes the lamp voltage as a function of temperature, the current switching state, and the desired switching state. Switch or t Switch The lamp voltage required for can be ascertained by the control unit as a function of the ascertained temperature (for example 60° C.) and applied to the functional element.

[0029] In the data set, if the lamp voltage is linear, a lamp voltage will be assigned to each temperature value. The data set can be created, for example, so that individual points are known by measured values ​​and interpolation (e.g., linear interpolation) is performed between them. However, in principle, the data set can also exist in a table-like format, where each lamp voltage is assigned to a specific temperature zone (e.g., 1°C to 2°C) or a discrete temperature value (e.g., exactly 1.0°C). The latter is less preferred because it is much more complicated to ascertain the measured values ​​for all temperatures.

[0030] The temperature-dependent switching time may be longer when switching from a switching state with a relatively high transparency or light transmittance to a switching state with a relatively low transparency or light transmittance (a down-switching state) than when switching from a switching state with a relatively low transparency or light transmittance to a switching state with a relatively high transparency or light transmittance (an up-switching state). This means, for example, that switching from a switching state with 40% transparency to a switching state with 70% transparency requires a shorter switching time than switching in the opposite direction. Thus, the switching time depends on the direction of the desired switching state. Therefore, the ramp voltage is preferably set so that when the voltage is applied to the functional element, the switching time t Switch occurs for both a change to a lower switching state and a change to an upper switching state. The data set thus preferably has a different lamp voltage assigned to each temperature within the predefined temperature range. If the control unit has programmed functions, the programmed functions preferably have a function for a change to an upper switching state and a function for a change to a lower switching state.

[0031] The required switching time t, which is typically temperature dependent, maxis significantly extended at temperatures below 10°C compared to the switching time at temperatures above 10°C. For common functional elements, the limit temperature is typically around 10°C. Temperatures below 10°C occur especially for seasonal and weather reasons. The time t at a temperature of 20°C max is typically less than 0.5 seconds. In contrast, at a temperature of -10°C, the time t max is typically 5 seconds or more. This time difference at different temperatures may increase as the temperature decreases and depending on the functional element. Therefore, preferably, the at least two switching states have a time required for changing between the two switching states that is longer at a relatively low temperature than at a relatively high temperature.

[0032] Preferably, the functional element is divided into at least two separate segments, each electrically connected to a control unit, so that a voltage at the lamp voltage can be applied to each segment independently. The functional element can also be divided into more than two separate segments. Particularly preferably, the functional element is divided into three or more separate segments, very particularly preferably into five or more, especially ten or more separate segments. The division into different segments allows the functional element to be controlled on demand. By means of the independently controllable segments, the user can define which areas of the glazing unit are transparent and which areas are darkened, opaque, or provided with high light scattering (semi-transparency). If the glazing unit is used, for example, as a roof pane in a vehicle, excessive heating of the interior of the vehicle can be avoided by selectively controlling the individual segments depending on the position of the sun. It is also possible to assign each occupant, ie, for example, the driver, the front seat passenger, the left rear seat passenger, and the right rear seat passenger, a respective segment located above them.

[0033] In a particular embodiment of the invention, the functional element is controlled in an animated manner, in which a voltage is initially applied to a first segment of at least two separate segments, and a switching time t SwitchOnly after the first segment has been switched to another switching state, the voltage is applied to the second segment. Thus, the second segment changes only after the first segment has been switched to another switching state. The voltage is preferably applied to the second segment immediately after the first segment has been switched to another switching state. In this context, "immediately" preferably means a time of 1 second or less, particularly preferably 0.5 seconds or less, and especially 0.1 seconds or less. In this case, the at least two second segments preferably change to the same switching state. Other animation methods are also possible. If the functional element is divided into more than two segments, adjacent segments may be switched consecutively in the manner described above. However, it is also possible to switch the outer segments first, and then the adjacent inner segments consecutively. Naturally, the reverse order is also possible.

[0034] In a further preferred embodiment of the invention, the functional element is used with another animation method, in which a voltage is applied to all of the at least two segments simultaneously, so that all of the at least two segments change to the desired switching state simultaneously. Alternatively, the voltage for changing the switching state is applied to all of the at least two segments consecutively with a small time delay, preferably a maximum of 5 seconds, particularly preferably a maximum of 1 second.

[0035] A control unit is provided, suitable for controlling the optical properties of the functional element. The control unit is conductively connected to the functional element or optionally individual segments of the functional element on the one hand, and to a voltage source on the other hand. The control unit includes the electrical and / or electronic components necessary to apply the required voltage to the planar electrodes as a function of their switching states. The switching states can be predefined by a user (e.g., by operating a switch, a button, or a rotary or sliding controller), determined by a sensor, and / or sent via a digital interface from the vehicle's central control device (which, if the laminated pane is a vehicle window pane, is typically a LIN bus or a CAN bus). The switch, button, rotary or sliding controller can be integrated, for example, into the vehicle dashboard if the laminated pane is a vehicle window pane. However, touch sensors can also be integrated directly into the laminated pane, e.g., capacitive or resistive sensors. Alternatively, the functional elements may also be controlled in a contactless manner, for example by recognizing gestures or as a function of the state of the pupils or eyelids determined by a camera and suitable evaluation electronics. The control unit may, for example, comprise an electronic processor, voltage converters, transistors, capacitors, diodes, and other components.

[0036] The voltage applied to the functional element is an AC voltage when the functional element is an SPD functional element or a PDLC functional element, and a DC voltage when the functional element is an electrochromic functional element.

[0037] Even if the functional element is a PDLC or SPD functional element, the voltage source may still be a DC voltage source. This situation occurs, for example, in vehicles when the laminated pane is a vehicle pane and is connected to the vehicle voltage. The control unit is preferably connected to the vehicle electrical system, from which it receives information about the voltage and, optionally, the switching state to be set. The control unit then comprises at least one inverter to convert the DC voltage to an AC voltage. In a first embodiment, the control unit comprises a single inverter, which optionally has multiple independent outputs for separately operating segments of the functional element, each segment being connected to one of the outputs. In this way, each segment or the entire functional element is assigned to an output of the inverter and is thereby electrically connected. The individual outputs are typically realized by switches, where the inverter generates a voltage that is then switched. These switches can be integrated directly into the inverter. Alternatively, however, the inverter itself may, strictly speaking, have only a single output to which an external switch is connected, thereby distributing the voltage to the segments of the functional element. In the sense of the present invention, such an externally connected switch is also considered an output of the inverter. In a second embodiment, if the functional element has at least two segments, the control unit has multiple inverters, where each segment is connected to a separate inverter for separate segment operation. Thus, each segment is electrically connected to the inverter. The first embodiment has the advantage of being relatively cost-effective and space-saving. However, it has the disadvantage that, if the functional element is divided into at least two segments, the segments can only be digitally controlled, so to speak, optically. It is not possible to provide the segments with a limited number of different switching states (so to say, to make them independently "dimmable"), which is possible without problems in the second embodiment.

[0038] One or more inverters can be operated to generate a real AC voltage, including its negative voltage component relative to the control device's supply voltage. However, this solution is technically relatively complex, since a negative potential is not available in the case of a DC voltage source, such as in a vehicle. Alternatively, it is possible, and often preferred, to simply simulate the AC voltage. In this case, the control unit includes two inverters, and the functional element is electrically connected to both inverters. The potentials of the inverters are adjusted according to various functions, for example, sinusoidal functions, with the potentials of the first inverter being in phase and the potentials of the second inverter being out of phase, particularly with a 180° phase shift. The signal of the first inverter is then inverted relative to the signal of the second inverter. In this way, a time-varying, periodic potential difference is generated, alternating between a relatively positive contribution and a relatively negative contribution, which corresponds to an AC voltage. If the functional element is divided into at least two segments, each segment is electrically connected to two different inverters, thereby adjusting the AC voltage for each segment. "Different inverters" does not mean that each inverter cannot also be connected to multiple segments.

[0039] The on-board voltage of a vehicle (e.g., 12-14 V) is typically not sufficient to fully optically control the functional element. For this reason, regardless of whether the functional element is a PDLC functional element, an SPD functional element, or an electrochromic functional element, the control unit further preferably comprises a DC-DC converter, which is suitable for increasing the supplied supply voltage (primary voltage), i.e., converting it to a relatively high secondary voltage (e.g., 65 V). The control unit is connected to a DC voltage source, which supplies the primary voltage. The DC-DC converter converts the primary voltage to a relatively high secondary voltage. In an advantageous embodiment, the secondary voltage is 5 V to 70 V, and the AC voltage is 5 V to 50 V. If the functional element is not an electrochromic functional element, the secondary voltage is converted to an AC voltage (e.g., 48 V) by an inverter.

[0040] According to the present invention, the temperature of the functional element is ascertained, whereby a lamp voltage is selected or calculated based on this temperature, and thereby applied. It is assumed here that the laminated pane has a uniform temperature throughout, i.e., the temperature of the functional element coincides with the temperature of other areas of the laminated pane, which is typically at least approximately the case. Thus, ascertaining the temperature of the laminated pane corresponds at least approximately to ascertaining the temperature of the functional element.

[0041] In an advantageous embodiment, the laminated pane comprises a temperature sensor. The temperature sensor is connected to the control unit so that the control unit can determine the temperature of the laminated pane, and thus the temperature of the functional element, by means of the temperature sensor. In this way, the measurement signal of the temperature sensor is sent to the control unit and evaluated there, so that the control unit can determine the temperature of the laminated pane by means of the temperature sensor. The temperature sensor can be integrated into the laminated pane. Alternatively, the temperature sensor can be fixed to the exterior of the laminated pane or assigned to it. Preferably, the temperature sensor is fixed to the surface of the laminated pane facing the interior (e.g., the interior of the vehicle). The temperature sensor can also be arranged in the control unit itself or in a fixing element, whereby the control unit is fixed to the laminated pane. In principle, a temperature sensor can also be used that is not directly fixed to the laminated pane or integrated therein, but measures the temperature at a distance, for example, an IR sensor arranged near and directed towards the laminated pane.

[0042] In a further advantageous embodiment, the control unit is adapted to determine the electrical impedance of the functional element and, therefrom, determine the temperature of the functional element. This is possible because the impedance (which, in the case of an AC voltage, corresponds to a conventional ohmic resistance) depends on the temperature. In particular, an injective relationship exists between the real part of the electrical impedance and the temperature of the functional element. In this way, a temperature can be assigned to each impedance. In particular, the real part of the impedance as a function of temperature strictly monotonically decreases as the temperature increases. This embodiment has the advantage that a temperature sensor can be omitted, which would have to be incorporated as an additional component, thus complicating the structure and increasing manufacturing costs. The method is implemented so that the control unit determines the impedance of the functional element and, therefrom, determines or estimates the temperature. For this purpose, a voltage is applied, in particular, and the resulting current is determined. The impedance can be calculated as the quotient of the voltage and the current. Impedance data, e.g., an impedance curve or an impedance table, describing 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), are stored in the control unit. By comparing the magnitude of the measured impedance against the impedance data, the control unit can approximately ascertain the temperature.

[0043] To determine the impedance, various embodiments are possible, in particular with regard to the measurement of power consumption. If the control unit has at least one inverter, this converts the input DC voltage into an output AC voltage, whereby the inverter's output current is measured. The problem here is that the current thus determined ("apparent current" or "total current") consists of two components: a reactive current (metaphorically speaking, resulting from the "pushing back and forth" of electrons as a result of the AC voltage and capacitively acting functional elements) and an active current (resulting from parasitic losses in the supply lines and functional elements). However, only the active current is decisive for determining the impedance (more precisely, its real part). The active component of the measured current (active current) then needs to be calculated by the control unit from the total current, for example by determining the phase shift between the voltage and the apparent current.

[0044] If the functional element is a PDLC or SPD functional element, the impedance can be determined in a particularly preferred variant from a measurement of the inverter's current consumption. A control unit is suitable for this determination. Since only a DC voltage is present, any reactive current will disappear over time on average unless it is absorbed by a capacitor in the inverter's intermediate circuit. Taking into account the loss factors in the inverter, the measured current can thus be used directly as the basis for determining the impedance. A further advantage is that this current measurement is often performed for fault detection (short circuits and overloads), which can avoid additional component costs.

[0045] A further possibility for determining the temperature of the functional element is to use an estimation algorithm. The estimation algorithm is preferably installed in the control unit and executed there. The temperature of the functional element is estimated based on one or more measurement signals. The signals for temperature estimation can be measurement data, preferably internal temperature, external temperature, thermal radiation (infrared, secondary heat, and / or ultraviolet), and / or measurement data related to the driving speed when the laminated pane is used as a vehicle pane in a vehicle. The signals are measured via sensors, typically installed in the vehicle, and sent to the control unit. Alternatively, sensors can be placed near the laminated pane, especially for the purpose of temperature estimation. In any case, the sensors are connected to the control unit. The estimation algorithm can estimate the temperature based on the measured signals. The temperature is a function of one or more signals; thus, the signal is the initial range and the temperature is the final range. The temperature of the functional element can be determined by the estimation algorithm whether the functional element is a PDLC functional element, an SPD functional element, or an electrochromic functional element.

[0046] In a preferred embodiment, the functional element is a PDLC (polymer-dispersed liquid crystal) functional element. PDLC functional elements contain liquid crystals embedded in a polymer matrix. When no voltage is applied to a PDLC functional element, the liquid crystals are aligned in a disordered manner, resulting in a strong scattering of light passing through the active layer (semitransparent). When a voltage is applied to the functional element, the liquid crystals are aligned in a common direction, resulting in a high light transmittance through the functional element (transparent). However, it is also possible for the liquid crystals to be ordered when no voltage is applied and to be accordingly disordered when a voltage is applied. However, other functional elements may also be used, the variability of whose optical properties is based on liquid crystals, for example, PNLC (polymer-networked liquid crystal) functional elements. When the application of a voltage is mentioned in connection with a functional element such as a PDLC functional element, it is always an AC voltage within the meaning of the present invention (not the instantaneous voltage, but the RMS value of the AC voltage).

[0047] In a further preferred embodiment, the functional element is an SPD (Suspended Particle Device) functional element. In this case, the SPD functional element contains suspended particles. The suspended particles change the optical state of the functional element by absorbing light as a result of the application of a voltage. In this way, the SPD functional element has switching states with transparent and opaque optical properties, as well as intermediate stages between transparent and opaque. When the application of a voltage is mentioned in connection with a functional element such as an SPD functional element, an AC voltage in the sense of the present invention (not the instantaneous voltage, but the RMS value of the AC voltage) is always meant.

[0048] In a further preferred embodiment, the functional element is an electrochromic functional element. In this case, the transmittance of visible light through the functional element depends on the degree of ion embedding. The ions are, for example, released by an ion storage layer and embedded in the electrochromic layer. The transmittance can be influenced by a voltage applied to the functional element, which causes the ions to migrate. A suitable electrochromic layer contains, for example, at least tungsten oxide or vanadium oxide. When the functional element is an electrochromic functional element, the control unit preferably does not include an inverter, and a DC voltage is applied to the functional element. However, a DC-DC converter for reaching a voltage in the range of 1 V to 50 V, preferably 10 V to 42 V, can be a component of the control unit, if necessary.

[0049] In a further preferred embodiment, the functional element is an SPD functional element or a PDLC functional element. The switching speed of the functional element can be significantly and relatively favorably influenced by the lamp voltage when the functional element is operated by an AC voltage. In particular, the functional element is a PDLC functional element. Experiments have shown that the technical effect of the present invention is particularly advantageously developed for PDLC functional elements.

[0050] The aforementioned controllable functional elements and their modes of operation are known per se to those skilled in the art and therefore may not be described in detail at this point.

[0051] The laminated pane preferably has at least one outer pane and one inner pane connected to one another via a thermoplastic interlayer.

[0052] In the context of the present invention, an "inner pane" refers to a pane facing the interior. An "outer pane" refers to a pane facing the exterior environment. The outer pane and the inner pane each have an exterior side surface and an interior side surface, and circumferential side edge surfaces extending therebetween. In the context of the present invention, the "exterior surfaces of the inner pane and the outer pane" refer to the major surfaces that are provided to face the exterior environment in the installed position. In the context of the present invention, the "inner surfaces of the inner pane and the outer pane" refer to the major surfaces that are provided to face the interior in the installed position. Thus, the interior surfaces of the outer pane and the exterior surfaces of the inner pane face each other and are connected to each other by a thermoplastic intermediate layer.

[0053] The thermoplastic intermediate layer serves to connect the inner and outer panes, as is common in laminated panes. A thermoplastic film is typically used, from which the intermediate layer is formed. In a preferred embodiment, the intermediate layer is formed from at least a first thermoplastic layer and a second thermoplastic layer, with a functional element disposed therebetween. The functional element is then connected to the outer pane through an area of ​​the first thermoplastic layer and to the inner pane through an area of ​​the second thermoplastic layer. The thermoplastic layers preferably protrude circumferentially beyond the functional element. When the thermoplastic layers are in direct contact with each other and are not separated from each other by a functional element, the thermoplastic layers may be joined together during lamination such that the original layers are no longer distinguishable, and instead a homogeneous intermediate layer is present.

[0054] The thermoplastic layer may be formed, for example, by a single thermoplastic film. The thermoplastic layer may also be formed from pieces of different thermoplastic films, the side edges of which are attached to one another.

[0055] In a preferred embodiment, the functional element, or more precisely, the side edges of the functional element, are circumferentially surrounded by a third thermoplastic layer. The third thermoplastic layer is frame-like, having a recess into which the functional element is inserted. The third thermoplastic layer can be formed by a thermoplastic film into which the recess is introduced by cutting. Alternatively, the third thermoplastic layer can also be composed of multiple film pieces around the functional element. The intermediate layer is formed from at least three thermoplastic layers arranged flat on top of each other, each having a recess into which the functional element is placed. During production, the third thermoplastic layer is arranged between the first and second thermoplastic layers, and the side edges of all thermoplastic layers preferably coincide. The third thermoplastic layer preferably has approximately the same thickness as the functional element. This compensates for local thickness differences introduced by the locally limited functional element, thereby avoiding glass breakage during lamination and providing an improved appearance.

[0056] The layers of the interlayer are preferably made of the same material, but in principle can also be made of different materials. The interlayer layer or film is preferably based on polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), or polyurethane (PU). This means that the layer or film mainly contains (more than 50% by weight) the above material and can optionally contain further components, such as plasticizers, stabilizers, UV absorbers, or IR absorbers. The thickness of each thermoplastic layer is preferably 0.2 mm to 2 mm, particularly preferably 0.3 mm to 1 mm. For example, films with standard thicknesses of 0.38 mm or 0.76 mm can be used.

[0057] The outer and inner panes are preferably made of glass, particularly preferably soda-lime glass, as is customary for window panes. However, the panes can also be made of other types of glass, such as quartz glass, borosilicate glass, or aluminosilicate glass, or hard clear plastics, such as polycarbonate or polymethyl methacrylate. The panes can be clear, or they can be tinted or colored. Depending on the application, there may be limitations on the degree of coloring or coloring: for example, it may be necessary to ensure a certain light transmittance, such as at least 70% light transmittance in the main field of view A, according to Regulation No. 43 of the United Nations Economic Commission for Europe (UN / ECE) (ECE-R43, "Uniform provisions concerning the approval of safety glazing materials and their installation in vehicles").

[0058] The outer pane, inner pane, and / or intermediate layer may have a suitable coating known per se, such as an anti-reflective coating, a non-stick coating, an anti-scratch coating, a photocatalytic coating, an ultraviolet absorbing or reflective coating, or an infrared absorbing or reflective coating, such as a sun protection coating, or a Low-E coating.

[0059] The thickness of the outer and inner panes can vary widely and can therefore be adapted to the requirements of each individual case. The outer and inner panes preferably have a thickness of 0.5 mm to 5 mm, particularly preferably 1 mm to 3 mm.

[0060] The laminated pane may be provided with an opaque cover print, particularly in the peripheral region, as is common in the vehicle field, particularly for windshields, rear windows, and roof panes. The cover print is typically made of enamel containing glass frit and pigment, particularly black pigment. The printing ink is typically applied by screen printing and then baked. Such a cover print is applied to at least one of the pane surfaces, preferably the inner surface of the outer pane and / or inner pane. The cover print preferably surrounds the central see-through region in a frame-like manner and serves to protect, in particular from ultraviolet light, the adhesive by which the laminated pane is connected to the vehicle body. If a control unit is attached to the inner surface of the inner pane, it will preferably be attached within the opaque region of the cover print.

[0061] The laminated pane according to the present invention includes a functional element with electrically controllable optical properties, which is preferably disposed between the outer and inner panes, i.e., embedded in the intermediate layer. The functional element is particularly preferably disposed between at least two intermediate layers of thermoplastic material, with the first layer connecting the outer pane and the second layer connecting the inner pane. However, alternatively, the functional element can also be disposed directly on the surface of the outer or inner pane facing the intermediate layer. Preferably, the side edges of the functional element are completely surrounded by the intermediate layer, so that the functional element does not extend to the side edges of the laminated pane and therefore does not come into contact with the ambient atmosphere.

[0062] If the temperature sensor is integrated into the laminated pane, this means that the temperature sensor is laminated between the outer and inner panes. The temperature sensor is preferably embedded in an intermediate layer, particularly preferably between at least two intermediate layers of thermoplastic material. Preferably, the temperature sensor is positioned adjacent to the functional element so that the temperature sensor is at a distance of no more than 2 cm, particularly preferably no more than 1 cm, from the functional element.

[0063] In a particularly preferred embodiment, the functional element comprises at least one active layer and first and second planar electrodes disposed on both sides of the active layer, such that the active layer is disposed between the first and second planar electrodes. The planar electrodes and the active layer are typically disposed essentially parallel to the surfaces of the outer and inner panes. The active layer has various optical properties that can be controlled by applying a voltage to the active layer via the planar electrodes. Thus, the active layer preferably comprises at least liquid crystals in a polymer matrix in the case of a PDLC functional element, at least suspended particles in the case of an SPD functional element, or at least an ion storage layer and an electrochromic layer in the case of an electrochromic functional element.

[0064] The first planar electrode preferably has at least two electrode segments separated from each other by an insulating line. The term "insulating line" is understood to mean a linear region where the material of the planar electrode is absent, thereby physically separating adjacent segments and thus electrically isolating them from each other. This means that there is no direct electrical connection between the electrode segments, but the electrode segments may be indirectly connected to each other in a somewhat conductive manner via the active layer in contact with them. The first planar electrode may be subdivided into multiple segments by multiple insulating lines. Each electrode segment represents a segment of a functional element. The number of electrode segments can be freely selected depending on the desired number of segments of the functional element. In a preferred embodiment, the insulating lines extend substantially parallel to each other and extend from one side edge of the planar electrode to the opposite side edge. However, any other geometric shape is also conceivable. Using insulating lines to form the electrode segments of the functional element is a cost-effective and simple method for creating the segments of the functional element. The second planar electrode and the active layer preferably form integral layers that are joined together.

[0065] The interruption lines have a width of, for example, 5 μm to 500 μm, in particular 20 μm to 200 μm. They are preferably introduced into the planar electrode by laser radiation. The width of the segments, i.e., the distance between adjacent interruption lines, can be appropriately selected by those skilled in the art according to the requirements of each individual case.

[0066] In a particularly preferred embodiment, the second planar electrode has at least two electrode segments that have interruption lines extending parallel to the first planar electrode, so that both the first and second planar electrodes are aligned when viewed through the laminated pane. This arrangement prevents so-called crosstalk effects between the segments of the functional element. Crosstalk effects refer to changes in the switching state of segments that are actually voltage-free but whose switching state is changed by an adjacent segment to which a voltage is applied. However, in principle, it is conceivable for the second planar electrode to be segmented to a lesser extent than the first planar electrode, i.e., to have fewer interruption lines and electrode segments, so that multiple electrode segments of the first planar electrode are assigned to at least one electrode segment of the second planar electrode. This can result in cost savings.

[0067] The electrode segments of the first planar electrode are electrically connected independently to a control unit, thereby applying a first potential (which, in the case of an AC voltage, varies over time) to each electrode segment (independently of the other electrode segments). The second planar electrode is similarly electrically connected to the control unit, thereby applying a second potential to the second planar electrode as a whole. In this manner, a ramp voltage is applied between each electrode segment and the second planar electrode. If the second planar electrode is similarly divided into electrode segments, each electrode segment of the second planar electrode is also electrically connected independently to the control unit. When the first and second potentials are the same, no voltage is applied between the electrodes within each segment (0% switching state). When the first and second potentials are different, a voltage is applied between the electrodes within each segment, thereby creating a finite switching state. For electrochromic functional elements, the first and second potentials are not the same because an equilibrium voltage can occur even at the 0% switching state. However, very little current flows at this equilibrium voltage, so the switching state only changes when a voltage from a voltage source is applied.

[0068] The planar electrodes are preferably transparent, which in the context of the present invention means that they have a light transmittance in the visible spectrum of at least 50%, preferably at least 70%, particularly preferably at least 80%. The planar electrodes preferably contain at least one metal, one metal alloy, or one transparent conductive oxide (TCO). Planar electrodes may be based on, for example, silver, gold, copper, nickel, chromium, tungsten, indium tin oxide (ITO), gallium- or aluminum-doped zinc oxide, and / or fluorine- or antimony-doped tin oxide, preferably silver or ITO. The planar electrodes preferably have a thickness of 10 nm to 2 μm, particularly preferably 20 nm to 1 μm, and very particularly preferably 30 nm to 500 nm.

[0069] In an advantageous embodiment, the functional element comprises two carrier films in addition to the active layer and the first and second planar electrodes, with the active layer and the planar electrodes preferably being arranged between the carrier films. The carrier film is preferably based on a thermoplastic material, such as polyethylene terephthalate (PET), polypropylene, polyvinyl chloride, fluorinated ethylene propylene, polyvinyl fluoride, or ethylene tetrafluoroethylene, and particularly preferably based on PET. The thickness of the carrier film is preferably 10 μm to 200 μm. Such functional elements may advantageously be provided as multilayer films, especially commercially available multilayer films, which may be cut to the desired size and shape and then laminated into a laminate pane, preferably via a thermoplastic layer having an outer pane and an inner pane in each case. The first and / or second planar electrodes, even when embedded in such a multilayer film, may be segmented by laser irradiation. Thin, visually inconspicuous interruption lines may be created by laser processing, typically without damaging the overlying carrier film.

[0070] The peripheral side edges of the functional element may be partially or completely sealed, for example by melting the carrier layer or by means of a (preferably polymeric) tape. The optionally present active layer may be protected in this way, and in particular components of the intermediate layer (especially plasticizers) may be protected from diffusing into the functional element, which may lead to degradation of the functional element.

[0071] For electrical contact of the functional elements or segments, the functional elements are preferably connected to so-called flat or foil conductors, which emerge from the intermediate layer and extend beyond the side edges of the laminated pane. Flat conductors have a strip-shaped metallic layer as their conductive core, which, except for the contact surface, is typically surrounded by a polymeric insulating sheath. Optionally, so-called bus bars, such as strips of conductive foil (e.g., copper foil) or conductive printing, may be arranged on the planar electrodes, and the flat or foil conductors are connected to the bus bars. The flat or foil conductors are connected to the control unit directly or via further conductors.

[0072] In an advantageous embodiment, the control unit is fixed to the inner surface of the laminated pane, preferably the surface of the inner pane facing away from the intermediate layer. The control unit can, for example, be glued directly onto the surface of the laminated pane. In an advantageous embodiment, the control unit is inserted into a fixing element, which is then fixed to the inner surface of the laminated pane, preferably via an adhesive layer. Such fixing elements are also known as brackets in the vehicle industry and are typically made of plastic. The electrical connection of the laminated pane is facilitated by directly attaching the control unit to the laminated pane. In particular, long cables are not required between the control unit and the functional elements.

[0073] However, alternatively, the control unit could be unsecured to the laminated pane, for example, if the laminated pane is a vehicle pane, integrated into the vehicle's electrical system or secured to the vehicle body. The control unit is preferably located within the vehicle interior, out of sight, such as in the dashboard or behind paneling.

[0074] The invention also extends to a computer program product, which is installed in a control unit of a glazing unit according to the invention and which is suitable for: - instructing the control unit to check the temperature of the functional element, the control unit then checking the temperature of the functional element; - selecting the lamp voltage from the data set based on the ascertained temperature or calculating it by a programmed function; and - instructing the control unit to energize the functional element with the ramp voltage, the control unit then energizing the functional element with the ramp voltage.

[0075] The present invention also extends to a method for controlling a glazing unit having electrically controllable optical properties, in which a glazing unit according to the invention is provided, which comprises: (a) the control unit is instructed by the computer program article to ascertain the temperature of the functional element, and thereafter ascertains the temperature; (b) the computer program article selects the lamp voltage from the data set based on the ascertained temperature or calculates it by a programmed function; and (c) the control unit is instructed by the computer program article to apply a voltage to the functional element at the ramp voltage, and thereafter applies a voltage at the ramp voltage;

[0076] The present invention also relates to the use of a glazing unit according to the invention, in particular a laminated pane of a glazing unit according to the invention, in a building or in a means of transport on land, air or water, preferably as a vehicle window pane, in particular as an automobile window pane. The glazing unit or laminated pane can be used, for example, as a windshield, roof pane, rear wall pane or side pane.

[0077] In a particularly preferred embodiment, the glazing unit or laminated pane is a vehicle windshield. The functional element is preferably an electrically controllable sunscreen, which is arranged in the upper region of the windshield, while the majority of the windshield is not provided with the functional element. The optional segments are preferably arranged substantially parallel to the upper edge of the windshield at increasing distances from it. As a result of the independently controllable segments, the user can determine the extent of the area adjacent to the upper edge that is darkened or provided with high light scattering depending on the position of the sun, thereby preventing sun glare.

[0078] In yet another preferred embodiment, the glazing unit or laminated pane is a vehicle roof panel. The functional element is preferably disposed throughout the entire see-through region of the laminated pane. In a typical embodiment, this see-through region comprises the entire laminated pane, excluding a peripheral edge region where an opaque cover print is provided on at least one surface of the laminated pane. The functional element extends throughout the entire see-through region, with its side edges disposed within the opaque cover print and thus invisible to the observer. The optional segments are preferably disposed substantially parallel to the roof pane's forward edge (the edge facing the windshield) at increasing distances from it. The independently controllable segments allow a user to define which areas of the roof pane should be transparent and which areas should be dark or highly light-scattering, for example, depending on the sun's position, thereby avoiding excessive heating inside the vehicle. Additionally, each vehicle occupant, ie, for example, the driver, front seat passenger, left rear seat passenger, and right rear seat passenger, may be assigned a respective segment located above them.

[0079] The invention will now be explained in more detail with reference to the drawings and exemplary embodiments, which are schematic representations and are not drawn to scale. The drawings are not intended to limit the invention in any way, as shown below: FIG. 1 is a plan view of an embodiment of a glazing unit according to the present invention. FIG. 2 is a cross-sectional view through the glazing unit of FIG. FIG. 3 is an enlarged representation of region Z of FIG. FIG. 4 shows the functional elements of FIG. 1 in a circuit diagram. FIG. 5A is a diagram of the "switching on" of a typical electrically controllable functional element at 23° C. according to the switching time; FIG. 5B is a diagram of the "switching off" of a typical electrically controllable functional element at 23° C. according to the switching time; FIG. 6A is a diagram of the "switching on" of a typical electrically controllable functional element at -20° C. according to switching time. FIG. 6B is a diagram of the "switching off" of a typical electrically controllable functional element at -20° C. according to switching time. FIG. 7 is a representation of the method according to the invention in an animated manner.

[0080] FIGS. 1, 2, 3, and 4 each show details of a laminated pane 100 according to the present invention having electrically controllable optical properties. FIG. 1 shows a plan view of the laminated pane 100 according to the present invention, while FIG. 2 shows a cross-sectional view of the laminated pane shown in FIG. 1 along section line X-X'. FIG. 3 shows an enlarged area Z of the cross-sectional view of FIG. 2. The laminated pane 100 is provided, by way of example, as a roof pane for a passenger vehicle, and its light transmittance can be electrically controlled within a region. The laminated pane 100 has an outer pane 1 and an inner pane 2, which are connected to each other via an interlayer 3. The outer pane 1 and the inner pane 2 are made of soda-lime glass and can be optionally tinted. For example, the outer pane 1 has a thickness of 2.1 mm, and the inner pane 2 has a thickness of 1.6 mm.

[0081] The intermediate layer 3 has three thermoplastic layers 3a, 3b, and 3c, each formed by a 0.38 mm thick thermoplastic film made of PVB. The first thermoplastic layer 3a is connected to the outer pane 1, and the second thermoplastic layer 3b is connected to the inner pane 2. The third thermoplastic layer 3c, located between them, has a cutout into which the functional element 4 with electrically controllable optical properties is inserted so that it fits precisely, i.e., is flush with the entire surface. In this way, the third thermoplastic layer 3c forms a kind of mount 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, which can be switched from an opaque, non-transparent (semi-transparent) 0% switching state to a clear, transparent 100% switching state. The functional element 4 is a multilayer film consisting of an active layer 5 between a first planar electrode 8 and a second planar electrode 9, and two carrier films 6 and 7. The first carrier film 6 is in planar contact with the first planar electrode 8, and the second carrier film 7 is in planar contact with the second planar electrode 9. The active layer 5 contains a polymer matrix in which liquid crystals are dispersed, which align depending on the voltage (AC voltage) applied to the planar electrodes 8 and 9, thereby controlling the optical properties. The carrier films 6 and 7 are made of PET and have a thickness of, for example, 0.125 mm. Facing the active layer 5, the carrier films 6 and 7 are provided with a coating made of ITO with a thickness of approximately 100 nm, forming the planar electrodes 8 and 9. The planar electrodes 8 and 9 are connected to an electrical cable 14 via a busbar (not shown) (e.g., formed from a strip of copper foil), which creates an electrical connection to the control unit 10.

[0082] This control unit 10 is attached, for example, to the inner surface of the inner pane 2, facing away from the intermediate layer 3. For this purpose, for example, a fastening element (not shown) is glued to the inner pane 2, into which the control unit 10 is inserted. However, the control unit 10 does not necessarily have to be attached directly to the laminated pane 100. Alternatively, it may be attached, for example, to the dashboard or the vehicle body, or integrated into the vehicle's on-board electrical system.

[0083] The laminated pane 100 has a peripheral edge region provided with an opaque cover print 13. The cover print 13 is typically made of black enamel. It is imprinted in a screen printing process as a printing ink containing black pigment and glass frit and baked into the pane surface. The cover print 13 is applied, for example, to the inner surface of the outer pane 1 and also to the inner surface of the inner pane 2. The side edges of the functional elements 4 are covered by this cover print 13. The control unit 10 is located within this opaque edge region, i.e., glued onto the cover print 13 of the inner pane 2. The control unit 10 does not obstruct visibility through the laminated pane 100 and is visually unobtrusive. Furthermore, because it is located a short distance from the side edges of the laminated pane 100, only short cables 14 are advantageously required to electrically connect the functional elements 4.

[0084] The control unit 10 is in turn connected to the vehicle's on-board electrical system, which for simplicity's sake is not shown in Figures 1 and 2. The control unit 10 is suitable for applying a voltage according to a ramp voltage to the planar electrodes 8, 9 of the functional element 4, which is required for the desired optical state (switching state) of the functional element 4 as a function of a control signal specified by the driver, for example by pressing a button.

[0085] The functional element 4 includes, by way of example, four independent segments S1, S2, S3, and S4, whose switching states can be set independently of one another by the control unit 10. The segments S1, S2, S3, and S4 are arranged next to one another in a direction from the front edge of the roof pane toward the rear edge. The "front edge" refers to the edge of the roof pane that is closest to the front of the vehicle in the installed position, and the "rear edge" refers to the edge that is closest to the rear of the vehicle in the installed position. The segments S1, S2, S3, and S4 allow the vehicle driver to select (e.g., depending on the position of the sun) to provide a translucent state to only one region of the laminated pane 100, rather than the entire laminated pane 100, while leaving other regions transparent.

[0086] To form the segments S1, S2, S3, and S4, the first planar electrode 8 is interrupted by three interruption lines 8', which are arranged substantially parallel to one another and extend from one side edge to the opposite side edge of the functional element 4. The interruption lines 8' are typically introduced into the first planar electrode 8 by laser machining, dividing it into four electrode segments 8.1, 8.2, 8.3, and 8.4 that are materially separated from one another. Each electrode segment 8.1, 8.2, 8.3, and 8.4 is independently connected to a control unit 10. The control unit 10 is adapted to apply voltages independently between each of the electrode segments 8.1, 8.2, 8.3, and 8.4 of the first planar electrode 8 on the one hand and the second planar electrode 9 on the other hand, so that the portion of the active layer 5 located therebetween receives the voltage required to reach the desired switching state.

[0087] As shown in the equivalent circuit diagram of FIG. 4, the control unit 10 is connected to a voltage source 15 via the vehicle's on-board electrical system. In the vehicle field, the voltage source 15 typically provides a DC voltage (the vehicle's on-board voltage) in the range of 12 V to 14 V. The control unit 10 includes a DC-DC converter 11, which converts the on-board voltage (primary voltage) into a relatively high DC voltage, e.g., 65 V (secondary voltage). The secondary voltage must be high enough to realize 100% switching states of the functional element 4. The control unit 10 also includes an inverter 12, which converts the secondary voltage into an AC voltage. One pole of the inverter 12 is connected to the second planar electrode 9. For the other poles, the inverter 12 has several independent outputs, each connected to a respective electrode segment 8.1, 8.2, 8.3, 8.4, thereby allowing the switching states of the associated segments S1, S2, S3, S4 to be set independently of the others. When the switching state is 0%, no voltage is applied, since the electrode segments 8.1, 8.2, 8.3, 8.4 and the second planar electrode 9 always have the same potential. When the switching state of a segment S1, S2, S3, S4 is greater than 0%, a voltage is applied between the associated electrode segment 8.1, 8.2, 8.3, 8.4 and the second planar electrode 9. The voltage results in a current flowing through the associated part of the active layer 5.

[0088] The switching speed, and therefore the switching time, is temperature dependent. Temperatures below 10°C result in, in particular, the functional element 4 or segments S1, S2, S3, S4 having a relatively slow switching speed for changing between switching states. At temperatures above 10°C, such delays are generally non-existent or relatively insignificant. Thus, in any temperature range, for example from -20°C to 120°C, the required switching time t max There is always at least one temperature at which the switching time is longest. In this exemplary embodiment, this temperature is -20°C. Therefore, the switching time required to change between the two switching states is longest when the functional element 4 has a temperature of -20°C.

[0089] In addition to the temperature, the switching speed is also defined via a ramp voltage, by which a voltage is applied to the segments S1, S2, S3, S4 of the functional element 4. According to the present invention, this dependence of the switching speed is utilized in that a voltage due to the ramp voltage is applied to the planar electrodes 8, 9, the ramp voltage being selected as a function of the temperature of the functional element 4. For this purpose, a computer program stored in the control unit 10 first instructs the control unit 10 to check the temperature of the laminated pane 100 or the functional element 4. The control unit 10 checks the temperature, and as a function of the checked temperature, the computer program selects a ramp voltage from a data set stored in the control unit 10 or calculates it by a function programmed in the control unit 10, and instructs the control unit 10 to apply the selected or calculated ramp voltage to one or more segments S1, S2, S3, S4 of the functional element 4. The voltage is selected to achieve the desired switching state. Depending on the ascertained temperature, the lamp voltage selected from the data set or calculated by a programmed function may have one or more different values ​​(linear lamp voltage or non-linear lamp voltage), so that the switching speed at which the switching state changes is relatively large or relatively small depending on the lamp voltage. The lamp voltage is proportional to the switching time t Switch is selected so that a change in switching state occurs for all temperatures identified within the temperature range. Switch For example, the longest switching time t max , which is necessary in this example when the temperature of the functional element 4 is −20° C. In other words, the switching speed v Switch is the same for all temperatures and is artificially extended for all temperatures except -20°C.

[0090] However, for some functional elements 4 and temperatures, the time for increasing and decreasing the voltage may be of different lengths. Thus, the temperature-dependent time for switching may be longer when switching from a switching state with a relatively high transparency or a relatively high transmittance to a switching state with a relatively low transparency or a relatively low transmittance (down switching state) than when switching from a switching state with a relatively low transparency or a relatively low transmittance to a switching state with a relatively high transparency or a relatively high transmittance (up switching state). Thus, the ramp voltage may, for example, be selected or calculated in each case so that when a voltage is applied to the functional element 4, the switching time t Switch occurs for both a transition to a down switching state and a transition to an up switching state. In other words, the magnitude of the ramp voltage is different depending on whether a transition to a down switching state or a transition to an up switching state is occurring. This is because the switching rate v Switch has the consequence that {overscore (V)} is the same for both a change to an up switching state and a change to a down switching state.

[0091] To ascertain the temperature, the laminated pane 100 may, for example, be equipped with a temperature sensor, which transmits the measured temperature to the control unit 10. The temperature sensor may be omitted if the temperature of the functional element 4 is estimated, for example based on the impedance of the active layer 5. When a voltage is applied, a current flows through the active layer 5, the extent of which depends on the temperature-dependent electrical impedance. Once the current consumption due to the applied voltage is ascertained, the current or the impedance of the active layer 5 can be ascertained therefrom and can then be used to approximately ascertain the temperature. For this purpose, impedance data relating the impedance of the active layer 5 to the temperature are stored in the control unit 10.

[0092] Figures 5A, 5B, 6A, and 6B show graphs of transmittance as a function of time for a generic glazing unit. Figures 5A and 6A show the change from a switching state with a relatively low transmittance to a switching state with a relatively high transmittance (switching on). Figures 5B and 6B show the change from a switching state with a relatively high transmittance to a switching state with a relatively low transmittance (switching off). Transmittance indicates the percentage of light transmitted through the laminated pane. The laminated pane or functional element has a temperature of 23°C in Figures 5A and 5B and -20°C in Figures 6A and 6B. The signal to change the switching state occurs after 5 seconds for all curves (labeled "switching" in Figures 5A, 5B, 6A, and 6B). At 23°C, the change to the other switching state (switching on and switching off), respectively, is completed after less than 1 second. The switching behavior at -20°C in Figures 6A and 6B is different from that at 23°C. Switching on the functional element, i.e., changing from a switching state with a transmittance of about 20% to a switching state with a transmittance of about 47%, requires a switching time of about 5 seconds. Thus, the switching time is more than five times longer than in FIG. 5A at 23°C. This effect can be observed even more clearly during switching off. In this case, the transmittance decreases by only about 25% over 100 seconds, reaching a transmittance of about 32% within this time. Because the measurement was terminated after 105 seconds, the target switching state of 20% is not reached in FIG. 6B.

[0093] Temperature-dependent switching behavior with switching times lasting from less than one second to several minutes would be annoying to an unprofessional user of the glazing unit and could lead the user to reasonably assume that the glazing unit is not functioning properly.

[0094] FIG. 7 shows a flowchart illustrating an exemplary method according to the present invention. After the desired switching state of the functional element 4 having four segments S1, S2, S3, and S4 is set, a computer program product, for example, instructs the control unit 10 in a first method step to check the temperature of the functional element 4. The desired switching state is, for example, the switching state with the greatest change in optical properties, i.e., the switching state with, for example, a change from a minimum transparent switching state to a maximum transparent switching state. The temperature is checked, for example, by the control unit 10, based on the temperature-dependent impedance behavior of the functional element 4. In a second method step, a ramp voltage is selected, for example, by the computer program product, from a data set stored in the control unit 10, based on the checked temperature. In a third method step, the control unit 10 is instructed, for example, by the computer program product, to apply the required voltage using the selected ramp voltage in order to bring the first segment S1 of the four segments S1, S2, S3, and S4 to the desired switching state. These three method steps are performed in such a way that the switching time for changing the segment S1 to the desired switching state is determined as a switching time t Switch or the switching speed for changing from the minimum switching state to the maximum switching state is equal to the switching speed v Switch The result is that the switching time t Switch After the desired switching state is reached, the selected ramp voltage is applied to the second segment S2 of the four segments S1, S2, S3, S4. The switching time t Switch After this time, the procedure is repeated for the third segment S3, and then for the fourth segment S4 of the four segments S1, S2, S3, and S4. The second, third, and fourth segments S2, S3, and S4 also have switching times t to change their respective segments S2, S3, and S4 to the desired switching state. Switchapplies. Depending on the functional element 4, the voltage is either maintained after the desired switching state has been reached or a change occurs to a state in which no voltage is applied by the control unit. In the method shown here for a glazing unit with a PDLC functional element, as shown in Figures 1 to 4, a voltage is, for example, applied to each segment S1, S2, S3, S4 even after the desired switching state has been reached. In the case of an electrochromic functional element, a change occurs after the desired switching state has been reached to a state in which no voltage is applied by the control unit, i.e., no external voltage is applied.

[0095] In a first embodiment of the method according to the invention, at least the following steps are carried out after initiation: Start: [Enter desired switching states for segments S1, S2, S3, S4] The method begins by selecting the desired switching states for the four segments S1, S2, S3, S4; (a): [Checking the temperature of functional element 4] The temperature of the functional element 4 of the glazing unit is ascertained by the control unit 10 after being instructed by the computer program article; (b): [Select lamp voltage based on confirmed temperature] The lamp voltage is selected from a data set stored in the control unit 10 or calculated by a programmed function based on the temperature ascertained from (a); (c1): [Applying a ramp voltage to segment S1 until the desired switching state is reached] The voltage required to reach the desired switching state is applied to a first segment S1 of the four segments S1, S2, S3, S4 at the ramp voltage selected in (b), and further voltage is applied after the desired switching state is reached, so that the first segment S1 remains in the desired switching state; (c2): [Applying a ramp voltage to segment S2 until the desired switching state is reached] Switching time t of the first segment S1 Switch After the lapse of (a), a voltage is applied to the second segment S2 of the four segments S1, S2, S3, S4 at the ramp voltage selected in (b), and a voltage is further applied after the desired switching state is reached, so that the second segment S2 remains in the desired switching state; (c3): [Applying a ramp voltage to segment S2 until the desired switching state is reached] Switching time t of the second segment S2 Switch After the lapse of time, a voltage is applied to the third segment S3 of the four segments S1, S2, S3, S4 at the ramp voltage selected in (b), and a voltage is further applied after the desired switching state is reached, so that the third segment S3 remains in the desired switching state; (c4): [Applying a ramp voltage to segment S2 until the desired switching state is reached] The switching time t of the third segment S3 Switch After the lapse of time, a voltage is applied to the fourth segment S4 of the four segments S1, S2, S3, S4 at the ramp voltage selected in (b), and a voltage is further applied after the desired switching state is reached, so that the fourth segment S4 remains in the desired switching state; End: The method is complete and terminates.

[0096] In this way, the desired switching state is brought to the four segments S1, S2, S3, S4 sequentially, starting from the first segment S1 through the fourth segment S4. The desired switching state is reached over the course of the switching time tSwitch. The order may also be different; for example, the desired switching state may be brought to the fourth segment S4 first, then the third segment S3, then the second segment S2, and finally the first segment S1. There may also be fewer or more segments than the four segments S1, S2, S3, S4 shown here. Therefore, this method may be implemented similarly using a different number of segments. The segments may also be switched to different switching states. The present disclosure includes the following aspects. <Aspect 1> 1. A glazing unit with electrically controllable optical properties, comprising: a laminated pane (100) comprising a functional element (4) with electrically controllable optical properties, and a control unit (10) electrically connected to the functional element (4); wherein the control unit (10) has a data set or programmed function that assigns a lamp voltage to each temperature within a predefined temperature range; wherein the control unit (10): - Check the temperature, - selecting a lamp voltage from the data set based on the determined temperature or calculating a lamp voltage according to the programmed function; and - applying a voltage to the functional element (4) at the selected ramp voltage or the calculated ramp voltage. Suitable for glazing units. <Aspect 2> the functional element (4) has at least two switching states with different optical properties, and a temperature-dependent switching time is required for the change between the two switching states, so that in any temperature range there exists a temperature with a time tmax that corresponds to the longest possible required switching time, wherein, based on the ascertained temperature, the selected or calculated lamp voltage, respectively, results in a switching time tSwitch greater than or equal to tmax, whereby the switching time tSwitch occurs when a voltage is applied to the functional element (4); Here, "any temperature range" means a temperature range spanning at least 1°C, preferably at least 2°C, in particular at least 5°C, in a glazing unit according to embodiment 1. <Aspect 3> A glazing unit according to aspect 1 or aspect 2, wherein the functional element (4) is divided into at least two separate segments (S1, S2, S3, S4), and each segment (S1, S2, S3, S4) is electrically connected to the control unit (10), whereby the voltage according to the selected lamp voltage or the calculated lamp voltage can be applied to each segment (S1, S2, S3, S4) independently of each other. <Aspect 4> the control unit (10) is adapted to initially apply the voltage to a first segment (S1) of the at least two separate segments (S1, S2, S3, S4) and to apply the voltage to a further segment (S2) of the at least two separate segments (S1, S2, S3, S4) only after the switching time tSwitch, A glazing unit according to aspect 3, wherein the at least two separate segments (S1, S2, S3, S4) preferably change to the same switching state. <Aspect 5> A glazing unit according to any one of aspects 2 to 4, wherein the change between the two switching states requires a longer time tmax at a relatively low temperature than at a relatively high temperature. <Aspect 6> A glazing unit according to any one of aspects 1 to 5, wherein the functional element (4) is a PDLC functional element or an SPD functional element. <Aspect 7> A glazing unit according to any one of aspects 1 to 5, wherein the laminated pane (100) has an outer pane (1) and an inner pane (2), and the functional element (4) is arranged between the outer pane (1) and the inner pane (2). <Aspect 8> A glazing unit according to any one of aspects 1 to 7, wherein the functional element (4) has an active layer (5) between a first planar electrode (8) and a second planar electrode (9), and the electrically controllable optical properties of the functional element (4) are determined by the active layer (5). <Aspect 9> A glazing unit according to aspect 8, wherein the first and / or the second planar electrodes (8, 9) are formed on the basis of indium tin oxide (ITO). <Aspect 10> A method of controlling a glazing unit having electrically controllable optical properties, wherein the glazing unit according to any of aspects 1 to 9 is provided, wherein the control unit (10) (a) Checking the temperature; (b) selecting a lamp voltage from the data set based on the determined temperature or calculating a lamp voltage according to the programmed function; and (c) applying a voltage to the functional element (4) at the selected ramp voltage or the calculated ramp voltage; <Aspect 11> 11. The method of embodiment 10, wherein the temperature of the functional element (4) is measured using a temperature sensor attached to the laminated pane (100). <Aspect 12> 11. The method of claim 10, wherein the impedance of the functional element (4) is ascertained by the control unit (10), and the temperature of the functional element (4) is calculated by the impedance. <Aspect 13> 13. The method of claim 12, wherein the control unit (10) comprises a DC voltage converter (11) connected to a DC voltage source (15) and configured to convert a primary voltage of the DC voltage source (15) to a relatively high secondary voltage, and an inverter (12) configured to convert the secondary voltage to an AC voltage applied to the functional element (4), wherein the control unit (10) determines the impedance of the functional element (4) from a measurement of a current consumption of the inverter (12). <Aspect 14> A computer program product installed in a control unit (10) of a glazing unit according to any one of aspects 1 to 9 and adapted to carry out a method according to any one of aspects 10 to 13. <Aspect 15> Use of a glazing unit according to any one of aspects 1 to 9 as a window pane, in particular as a side pane, windshield, rear pane, or roof pane, of a vehicle. [Explanation of symbols]

[0097] S1, S2, S3, S4 Segments of functional element 4

[0098] 1 outer pane 2 inner panes 3 Thermoplastic Interlayer 3a First layer of middle layer 3 3b Second layer of middle layer 3 3c Third layer of middle layer 3 4 Functional elements 5 Active layer 6. First Carrier Film 7 Second Carrier Film 8 1st plane electrode 8.1, 8.2, 8.3, 8.4 Electrode segments of the first planar electrode 8 8' Interruption line between any two of the electrode segments 8.1, 8.2, 8.3, and 8.4 9 Second plane electrode 10. Control Unit 11 DC-DC converter 12 inverters 13 Cover printing 14 Electrical Cables 15 Voltage Source / DC Voltage Source

[0099] 100 stacked panes

[0100] X-X' section line Z expansion area

Claims

1. 1. A glazing unit with electrically controllable optical properties, comprising: a laminated pane (100) comprising a functional element (4) with electrically controllable optical properties, and a control unit (10) electrically connected to said functional element (4), wherein the control unit (10) has a data set or programmed function that assigns a lamp voltage to each temperature within a predefined temperature range; wherein said control unit (10) is: - Check the temperature, - selecting a lamp voltage from said data set based on said ascertained temperature or calculating a lamp voltage by said programmed function; and - applying a voltage to the functional element (4) with the selected ramp voltage or the calculated ramp voltage; Suitable for the functional element (4) has at least two switching states with different optical properties, and a temperature-dependent switching time is required for the change between the two switching states, so that in any temperature range there exists a temperature with a time t max that corresponds to the longest possible required switching time, wherein, based on said ascertained temperature, the selected or calculated lamp voltage, respectively, results in a switching time t Switch that is greater than or equal to t max , whereby said switching time t Switch occurs when a voltage is applied to said functional element (4); Here, "any temperature range" means a temperature range spanning at least 1°C, preferably at least 2°C, in particular at least 5°C of the glazing unit.

2. 2. A glazing unit as claimed in claim 1, wherein the functional element (4) is divided into at least two separate segments (S1, S2, S3, S4), each segment (S1, S2, S3, S4) being electrically connected to the control unit (10), whereby the voltage according to the selected lamp voltage or the calculated lamp voltage can be applied to each segment (S1, S2, S3, S4) independently of one another.

3. The control unit (10) is adapted to initially apply the voltage to a first segment (S1) of the at least two separate segments (S1, S2, S3, S4) and to apply the voltage to the first segment (S1) at a switching time t Ｓｗｉｔｃｈ 3. The glazing unit according to claim 2, which is suitable for application to a further segment (S2) of the at least two separate segments (S1, S2, S3, S4) only after

4. The transition between the two switching states takes a longer time t at a relatively low temperature than at a relatively high temperature. ｍａｘ The glazing unit of claim 1 , wherein the glazing unit is

5. 2. A glazing unit according to claim 1, wherein the functional element (4) is a PDLC functional element or an SPD functional element.

6. 2. The glazing unit according to claim 1, wherein the laminated pane (100) has an outer pane (1) and an inner pane (2), and the functional element (4) is arranged between the outer pane (1) and the inner pane (2).

7. 2. The glazing unit according to claim 1, wherein the functional element (4) has an active layer (5) between a first planar electrode (8) and a second planar electrode (9), and the electrically controllable optical properties of the functional element (4) are determined by the active layer (5).

8. 8. A glazing unit according to claim 7, wherein the first and / or the second planar electrode (8, 9) is made on the basis of indium tin oxide (ITO).

9. 10. A method for controlling a glazing unit having electrically controllable optical properties, in which the glazing unit according to claim 1 is provided, wherein the control unit (10) performs the following: (a) Checking the temperature; (b) selecting a lamp voltage from the data set based on the determined temperature or calculating a lamp voltage according to the programmed function; and (c) applying a voltage to the functional element (4) at the selected ramp voltage or the calculated ramp voltage.

10. 10. The method of claim 9, wherein the temperature of the functional element (4) is measured using a temperature sensor attached to the laminated pane (100).

11. 10. The method according to claim 9, wherein the impedance of the functional element (4) is ascertained by the control unit (10) and the temperature of the functional element (4) is calculated by means of said impedance.

12. 12. The method of claim 11, wherein the control unit (10) comprises a DC voltage converter (11) connected to a DC voltage source (15) and converting a primary voltage of the DC voltage source (15) into a relatively high secondary voltage, and an inverter (12) converting the secondary voltage into an AC voltage applied to the functional element (4), wherein the control unit (10) determines the impedance of the functional element (4) from measurements of the current consumption of the inverter (12).

13. A computer program product installed in a control unit (10) of a glazing unit according to claim 1 and suitable for carrying out the method according to any one of claims 9 to 12.

14. 10. Use of a glazing unit according to claim 1 as a window pane, in particular as a side pane, windshield, rear pane or roof pane, of a vehicle.

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