Method for controlling PDLC functional element having several independently switchable switching zones

Abstract

The invention relates to a method for controlling a PDLC functional element (4) having at least two adjacent, independently switchable switching zones (Sn, Sn + 1, n = 1... 8), in which a switching state (on, off) can be applied to the switching zones (Sn, Sn + 1) by means of a control unit (10), in which A) different switching states (on, off) are applied to the at least two adjacent switching zones (Sn, Sn + 1); b) sending a signal to the control unit (10) by a user or an automatic control device in order to change the switching state (on, off) in each switching zone (Sn, Sn + 1); c) firstly setting all the switching areas (S1, S2, S3, S4, S5, S6, S7, S8 and S9) to be in an'on 'switching state; and D) then applying the changed switching state to the switching zone (S1, S2, S3, S4, S5, S6, S7, S8, S9).

Description

[0001] The invention relates to a method for controlling a PDLC functional element having several independently switchable switching zones, a glazing unit and the use thereof.

[0002] Glazing units with electrically controllable optical properties are known per se. They comprise a laminated pane equipped with a functional element, the optical properties of which can be changed by an applied voltage. A voltage is applied via a control unit 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 (suspended particle device) functional element, which is known, for example, from EP0876608B1 and WO 2011033313A1. By applying a voltage, the transmission of visible light can be controlled by the SPD functional element. Another example is a standard PDLC (polymer dispersed liquid crystal) functional element, which is known, for example, from DE 102008026339 A1. The active layer comprises liquid crystals embedded in a polymer matrix. If no voltage is applied in the "off" switching state, the liquid crystals are aligned in a disordered manner, which results in a strong scattering of light passing through the active layer. In the "on" switching state, a voltage is applied to the planar electrodes to align the liquid crystals in a common direction and increase the transmittance of light passing through the active layer. PDLC functional elements thus work primarily by increasing scattering rather than by reducing total transmission, and thus can prevent clear view or can ensure anti-glare protection. Electrochromic functional elements are also known, for example from US20120026573A1, WO 2010147494A1 and EP 1862849 A1 and WO 2012007334 A1, in which the change in transmission is the result of an electrochemical process triggered by an applied voltage.

[0003] Such glazing units can be used, for example, as window panes, so that their optical properties can be electrically controlled. They can be used, for example, as roof panes to reduce exposure to direct sunlight or disturbing reflections. Such roof panes are known, for example, from DE 10043141 A1 and EP 3456913 A1. Windshields have also been proposed in which electrically controllable sun visors are implemented by switchable functional elements to replace conventional mechanically foldable sun visors in motor vehicles. Windshields with electrically controllable sun visors are known, for example, from DE 102013001334 A1, DE 102005049081 B3, DE 102005007427 A1 and DE 102007027296 A1.

[0004] It is also known to provide such glazing units or switchable functional elements in glazing units with a plurality of switching zones, the optical properties of which can be switched independently of one another. For example, one zone of the functional element can be selectively darkened or provided with a high level of light scattering, while other zones remain clear or transparent. Glazing units with independent switching zones and methods for their production are known, for example, from DE 202021105089 U1, WO 2014072137 A1 or WO 2017157626 A1.

[0005] The independent switching regions are usually formed by one of the planar electrodes subdivided into switching regions ((electrode) segments) by isolation lines, which are separated from each other and each independently connected to a control unit and can therefore be independently controlled, while the other planar electrode does not have any isolation lines, for example. The insulating lines are usually introduced into the planar electrodes by laser processing. The planar electrodes cannot be selected according to the best conductivity, because they must be transparent to ensure the transparency of the laminated glass sheet. An ITO layer with low conductivity or high resistance is usually used as the planar electrode.

[0006] An electrical control unit for controlling a functional element having electrically controllable optical properties is known, for example, from EP 3 910 412 A1.

[0007] It is an object of the present invention to provide an improved method for controlling a PDLC functional element having at least two adjacent, independently switchable switching zones.

[0008] This object is achieved according to the invention by a method for controlling a PDLC functional element having at least two adjacent, independently switchable switching zones, wherein a switching state (on, off) can be applied to the switching zones by a control unit, wherein

[0009] A) applying different switching states (on, off) to at least two adjacent switching zones;

[0010] B) The user or the automatic control device sends a signal to the control unit to change the switching state (on, off) in each switching area;

[0011] C) first setting all switching zones to the "on" switching state; and

[0012] D) The changed switching state is then applied to the switching region.

[0013] It should be understood that in step D), the switching zone to be set to "ON" may remain "ON".

[0014] The method according to the invention is characterized in that, in an (intermediate) step C, all switching zones are set to a uniform "on" switching state before applying a new switching state distribution to the switching zones. This restores the original memory state of the different switching states in the switching zones, and all switching zones exhibit the same optical properties again.

[0015] In an advantageous embodiment of the method according to the invention, in step C the “on” switching state is applied simultaneously in all switching zones.

[0016] In an advantageous embodiment of the method according to the invention, the "on" switching state is applied in the switching zone at different times in step C. Preferably, the "on" switching state is applied in the switching zone in a rolling function, i.e., for example, by switching on ("on" switching state) from one side of the PDLC functional element to the opposite side in a continuous sequence of individual switching zones, and particularly preferably back again. It should be understood that the method can be carried out several times in succession.

[0017] Alternatively, the switching zones can be switched in an alternating sequence. For example, in the case of a glazing having nine switching zones, the first, third, fifth, seventh and ninth switching zones can first be switched to "on", then these zones can be switched to "off", and the second, fourth, sixth and eighth switching zones can be switched alternately.

[0018] It should be understood that other sequences can be switched, for example switching continuously from opposite sides to the middle, that is, in the above example with 9 switching zones, starting from switching zones 1 and 9, then 2 and 8, then 3 and 7, then 4 and 6, and finally the middle switching zone 5.

[0019] In an advantageous embodiment of the method according to the invention, step D is only carried out after each switching zone has been set to the “on” switching state at least once.

[0020] In a further advantageous embodiment of the method according to the invention, the “on” switching state is maintained in the switching region for a time t greater than or equal to 1 / 60 s, preferably greater than or equal to 0.5 s, in particular 0.5 s to 10 s, in step C. This ensures an almost completely restored memory state and therefore a sufficient homogenization of the optical properties of the switching region.

[0021] This object is further achieved according to the invention by a glazing unit with a PDLC functional element, the glazing unit comprising

[0022] A laminated glass panel comprising:

[0023] - an outer pane and an inner pane, which are connected to one another via at least one thermoplastic intermediate layer;

[0024] - a PDLC functional element having at least two adjacent, independently switchable switching zones, which is arranged between an outer pane and an inner pane, wherein

[0025] - the PDLC functional element has at least two adjacent switching zones that can be switched independently,

[0026] and

[0027] a control unit for electrically controlling the optical properties of the switching zones of the PDLC functional element,

[0028] The control unit is provided to carry out the method according to the invention.

[0029] In an advantageous embodiment, the glazing unit according to the invention comprises a laminated glass pane, wherein the laminated glass pane comprises an outer glass pane and an inner glass pane connected to each other via a thermoplastic interlayer, and an electrically controllable functional element arranged between the outer glass pane and the inner glass pane. The functional element has an active layer with electrically controllable optical properties between a first planar electrode and a second planar electrode. The control unit is configured to control the optical properties of the functional element.

[0030] In another advantageous embodiment, the PDLC functional element comprises an active layer having electrically controllable optical properties and is arranged between a first planar electrode and a second planar electrode. Advantageously, the first planar electrode is divided into at least two separate electrode segments by at least one isolation line, wherein each electrode segment forms an independently switchable switching zone.

[0031] In another advantageous embodiment, the electrode segments of the first planar electrode and the second planar electrode are electrically connected to a control unit so that voltages can be applied independently between the electrode segments of the first planar electrode and the second planar electrode to control the optical properties of the active layer segment located therebetween.

[0032] In a further advantageous embodiment, the second planar electrode has no isolating lines or has a smaller number of isolating lines and thus a smaller number of electrode segments than the first planar electrode to assign several electrode segments of the first planar electrode to at least one electrode segment of the second planar electrode.

[0033] The invention is based on the finding that the switching behavior and optical properties of a typical PDLC functional element, such as diffusivity and transmission, depend on its wiring. The method according to the invention and the glazing unit according to the invention prevent the PDLC functional element from experiencing deviations in its optical properties in the switched-off state (“off” switching state) caused by the so-called “memory effect” of the PDLC functional element. This memory effect is a visible effect in that a switching zone (electrode segment) which was recently switched on (“on” switching state) has a different opacity and / or a different scattering behavior in the subsequent switched-off state (“off” switching state) than an adjacent PDLC switching zone which was switched off for a longer time (“off” switching state) and / or has a different switching history.

[0034] This can be remedied by briefly switching on ("on" switching state) all switching regions, which results in restoration of the original memory state and homogenization of the optical properties.

[0035] For example: in a standard PDLC functional element, if all odd-numbered switching zones of a glazing unit, for example, designed as a top glass plate with nine switching zones, are switched on for 5 minutes and then the entire top is switched off (made opaque), the passengers in the car can clearly see the difference in opacity between the odd-numbered and even-numbered switching zones. In order to prevent this unsatisfactory experience for customers, various countermeasures can be introduced at the system level, such as introducing a homogenization sequence after a certain switching operation (for example, switching all switching zones in a scrolling function); starting and ending the sequence or switching all switching zones on and off simultaneously. In other words, in order to achieve uniform optical properties, each switching zone must be switched regularly to keep all switching zones in a similar opacity or transmission state.

[0036] In the following, the glazing unit and the method are described together, wherein the explanations and preferred embodiments relate equally to the glazing unit and the method. If preferred features are described in conjunction with the method, this means that the glazing unit is preferably designed accordingly and is adapted accordingly. On the other hand, if preferred features are described in conjunction with the glazing unit, this means that the method is also preferably carried out accordingly.

[0037] The laminated glass panel according to the invention, in particular as part of a glazing unit according to the invention, comprises at least one outer glass panel and one inner glass panel, which are connected to each other via at least one thermoplastic interlayer. The laminated glass panel is used to separate an interior space from the external environment in a window opening, in particular a window opening or a roof opening of a vehicle, but alternatively also a window opening of a building or a room. In the present invention, the term "inner glass panel" is understood to mean a glass panel facing the interior space. The outer glass panel refers to a glass panel facing the external environment. The outer glass panel and the inner glass panel each have an outer side surface and an inner side surface and a circumferential side surface extending between them. In the sense of the present invention, the outer side surface refers to the main surface intended to face the external environment when installed. In the sense of the present invention, the inner side surface refers to the main surface intended to face the inside when installed. The inner side surface of the outer glass panel and the outer side surface of the inner glass panel face each other and are connected to each other via a thermoplastic interlayer.

[0038] The laminated glazing according to the invention contains a PDLC functional element with electrically controllable optical properties, which is arranged between the outer glass pane and the inner glass pane, i.e. embedded in the interlayer. The functional element is preferably arranged between at least two layers of thermoplastic material of the interlayer, wherein it is connected to the outer glass pane via a first layer and to the inner glass pane via a second layer. Alternatively, however, the functional element can also be arranged directly on the surface of the outer glass pane or the inner glass pane facing the interlayer. Preferably, the side edges of the functional element are completely surrounded by the interlayer, so that the functional element does not extend all the way to the side edges of the laminated glazing and is therefore not in contact with the surrounding atmosphere.

[0039] The PDLC functional element comprises at least one active layer and two planar electrodes arranged on both sides of the active layer, so that the active layer is arranged between the planar electrodes. The planar electrodes and the active layer are usually arranged substantially parallel to the surface of the outer glass plate and the inner glass plate. The active layer has variable optical properties, which can be controlled by the voltage applied to the active layer via the planar electrodes. In the present invention, electrically controllable optical properties are particularly understood to refer to such properties that are continuously controllable. In the present invention, the switching state of the functional element refers to the degree of change of the optical property compared to the no-voltage state. The 0% switching state corresponds to the no-voltage state, and the 100% switching state corresponds to the maximum change of the optical property. Between the above two states, all switching states can be continuously realized by selecting the voltage accordingly. For example, the 20% switching state corresponds to a change of the optical property to 20% of the maximum change. The optical property is particularly related to light transmission and / or scattering behavior.

[0040] In principle, however, it is also conceivable that the electrically controllable optical property can be switched between only two discrete states. In this case, there are only two switching states, for example 0% (off) and for example 100% (on). It is also conceivable that the electrically controllable optical property can be switched between more than two discrete states.

[0041] The planar electrodes are preferably transparent, which means in the present invention that they have a light transmission of at least 50%, preferably at least 70%, particularly preferably at least 80% in the visible spectral range. The planar electrodes preferably contain at least one metal, metal alloy or transparent conductive oxide (TCO). The planar electrodes can be formed, for example, based on silver, gold, copper, nickel, chromium, tungsten, indium tin oxide (ITO), gallium-doped or aluminum-doped zinc oxide and / or fluorine-doped or antimony-doped tin oxide, preferably based on silver or ITO. The surface electrode preferably has a thickness of 10 nm to 2 μm, particularly preferably 20 nm to 1 μm, very particularly preferably 30 nm to 500 nm.

[0042] According to the present invention, the first planar electrode has at least two segments (electrode segments) separated from each other by insulating lines. Insulating lines are understood to mean linear areas in which the material of the planar electrode is not present, so that adjacent segments are substantially separated from each other and are therefore electrically insulated from each other. This means that there is no direct electrical connection between the electrode segments, but the electrode segments can be indirectly connected to each other in a conductive manner to a certain extent via the active layer in contact with them. The first planar electrode can be subdivided into several segments by several insulating lines. Each electrode segment forms a switching zone for the glazing arrangement. Those skilled in the art can freely select the number of electrode segments on an individual basis as required. In a preferred embodiment, the isolating lines extend substantially parallel to each other and extend from one side of the planar electrode to the opposite side. However, any other geometry is also conceivable.

[0043] In the sense of the invention, two electrode segments which are separated only by an isolating line form adjacent switching regions, which can also be referred to as directly adjacent switching regions.

[0044] The isolating 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 means of laser radiation. A person skilled in the art can appropriately select the width of the segments, ie the distance between adjacent insulating lines, according to the requirements of the individual case.

[0045] The second planar electrode and the active layer preferably each form a coherent, complete layer that is not subdivided into segments by insulating lines. In principle, however, it is also conceivable that the second planar electrode is segmented to a lesser extent than the first planar electrode, i.e., has fewer insulating lines and electrode segments, so that a plurality of electrode segments of the first planar electrode are assigned to at least one electrode segment of the second planar electrode. In this case, crosstalk problems also occur, but they can be reduced by the method according to the invention. Each insulating line of the second planar electrode is arranged to coincide with an insulating line of the first planar electrode in the viewing direction through the laminated glass pane.

[0046] The electrode segments of the first planar electrode are electrically connected to a control unit independently of one another so that a first potential (which varies over time in the case of an AC voltage) can be applied to each electrode segment (independently of the other electrode segments), which potential is referred to as a switching potential in the present invention. The second planar electrode is also electrically connected to the control unit so that a second potential can be applied to the second planar electrode as a whole, which is referred to as a reference potential (ground) in the present invention. If the first and second potentials are the same, there is no voltage between the electrodes in the corresponding switching region ("off" switching state, 0%). If the first and second potentials are different, there is a voltage between the electrodes in the corresponding switching region, thereby producing a finite switching state.

[0047] In a variant of the invention, the second planar electrode is also segmented, but to a lesser extent than the first planar electrode, so that several electrode segments of the first planar electrode are assigned to at least one electrode segment of the second planar electrode. In this case, the electrode segments of the second planar electrode are also electrically connected to the control unit independently of each other, so that a second potential (reference potential, "ground") can be applied to each electrode segment (independently of the other electrode segments). However, the second planar electrode has at least one electrode segment that provides a reference potential for several switching zones. The affected switching zones can be controlled independently of each other, because switching potentials can be applied to the electrode segments of the first planar electrode independently of each other, while a single reference potential is applied to the relevant electrode segments of the second planar electrode.

[0048] A control unit is provided and is suitable for controlling the optical properties of a PDLC functional element. The control unit is conductively connected to the planar electrode of the functional element on the one hand and conductively connected to a voltage source on the other hand. The control unit contains electrical and / or electronic components required for applying a desired voltage to the planar electrode according to the switching state. The switching state can be predefined by the user (e.g., by operating a switch, button, or rotating or sliding controller), can be determined by a sensor and / or can be transmitted from a central control device of the vehicle (if the laminated glass plate is a window glass plate, usually a LIN bus or a CAN bus) through a digital interface. If the laminated glass plate is a window glass plate, a switch, button, rotating or sliding controller can be integrated in, for example, a dashboard of the vehicle. However, a touch sensor can also be directly integrated into the laminated glass plate, such as a capacitive or resistive sensor. Alternatively, the functional element can also be controlled by a non-contact method, such as by identifying a gesture, or according to the state of the pupil or eyelid determined by a camera and a suitable evaluation electronic device. The control unit can include, for example, an electronic processor, a voltage converter, a transistor and other components.

[0049] The voltage applied to the planar electrode is preferably an AC voltage. In a preferred embodiment, the voltage source is a DC voltage source that provides a DC voltage and supplies the DC voltage to the control unit. For example, if the laminated glass pane is a vehicle glass pane and is connected to the vehicle voltage, this situation will occur in the vehicle. The control unit is preferably connected to the vehicle electrical system, from which the voltage and, optionally, information about the switching state are obtained. The control unit is then equipped with at least one inverter to convert the DC voltage into an AC voltage. In a first embodiment, the control unit has a single inverter. In order to separately control the electrode segments of the first planar electrode, the output of the inverter has several independent outputs, wherein each electrode segment is connected to one of the outputs. An output of the inverter is therefore associated with each switching zone and connected to the corresponding electrode segment of the first planar electrode. Each output is usually implemented by a switch, wherein the inverter generates a voltage that is subsequently switched. These switches can be directly integrated in the inverter. However, alternatively, the inverter itself can also have strictly only a single output, and then an external switch is connected to it in order to distribute the voltage to the switching zone. In the sense of the present invention, such an externally connected switch is also regarded as the output of the inverter. The second planar electrode is also connected to the inverter. In a second embodiment, the control unit has several inverters, wherein each electrode segment is connected to its own inverter to separately control the electrode segments of the first planar electrode. One output of the inverter is therefore associated with each switching zone and connected to the corresponding electrode segment of the first planar electrode. The first embodiment has the advantage of being more cost-effective and more space-saving. However, its disadvantage is that the switching zone can only be digitally switched between a 0% switching state and a limited switching state, which corresponds to the output voltage of the inverter currently applied. Different limited switching states cannot be provided for the switching zones (as if they were independently "dimmable"), which can be achieved without problems in the second embodiment.

[0050] The inverter can be operated in a manner that generates a real AC voltage (including its negative component). This is possible both in the case of only a single inverter with independent outputs and in the case of allocating its own inverter to each switching zone. Since in the case of a DC voltage source, such as in the case of a vehicle, a negative potential cannot be provided anyway, this solution is technically complex. Alternatively, it is possible and often preferred to simulate an AC voltage. The control unit is equipped with several inverters, wherein each electrode segment of the first planar electrode is connected to a separate inverter and the second planar electrode is connected to another inverter. Therefore, each electrode segment of the first planar electrode and the second planar electrode is allocated its own inverter. The potential of the inverter is modulated with a variable function, such as a sine function, wherein the potential of the inverter of the electrode segment of the first planar electrode is in phase, while the potential of the inverter of the second planar electrode is phase-shifted, in particular with a phase shift of 180°. The signal of the second planar electrode is then inverted compared to the signal of the first planar electrode. A periodic potential difference variable in time is thereby generated, which has alternating relatively positive and relatively negative contributions, which correspond to an AC voltage.

[0051] The control unit is preferably equipped with a DC-DC converter in addition, which is suitable for improving the supplied feed voltage (primary voltage), that is, converting it into a higher secondary voltage (for example 65V). The use of the DC-DC converter is not limited to the situation in the vehicle, but may also be necessary or advantageous in other cases. The control unit is connected to a DC voltage source, and the primary voltage is provided by the DC voltage source. The DC-DC converter converts the primary voltage into a higher secondary voltage. The inverter converts the secondary voltage into its suitable AC voltage (for example 48V). Then the AC voltage is applied to the electrode segment of the first planar electrode on the one hand, and is applied to the second planar electrode on the other hand.

[0052] In an advantageous embodiment, the secondary voltage is 5V to 70V and the AC voltage is 5V to 50V.

[0053] In an advantageous development of the glazing unit according to the invention, the temperature of the laminated glass pane is determined.

[0054] In an advantageous development of the method according to the invention, the temperature T of the PDLC functional element is determined and steps AD of the method according to the invention are carried out only when the temperature T is greater than 50° C., preferably greater than 60° C.

[0055] In an alternative or combined development of the method according to the invention, the temperature T of the PDLC functional element is determined and steps A to D are carried out only if, after the last application of the "on" switching state to the PDLC functional element, a temperature distribution is passed at a certain point in time in which the temperature T is greater than 40° C., preferably greater than 50° C., particularly preferably greater than 60° C.

[0056] Alternatively or in combination, the voltage to be applied or the corresponding duration t of the “on” switching state can be adapted to the determined temperature.

[0057] It is assumed that the laminated glass pane has a uniform temperature overall, ie the temperature of the functional element matches the temperature of other regions of the laminated glass pane, which is usually the case at least approximately. Therefore, determining the temperature of the laminated glass pane corresponds at least approximately to determining the temperature of the functional element.

[0058] In an advantageous embodiment, the laminated glass pane is equipped with a temperature sensor. The temperature sensor is connected to the control unit so that the control unit can determine the temperature of the laminated glass pane with the aid of the temperature sensor. The measurement signal of the temperature sensor is therefore transmitted to the control unit and evaluated there so that the control unit determines the temperature of the laminated glass pane with the aid of the temperature sensor. The temperature sensor can be integrated into the laminated glass pane by embedding it in the interlayer. Alternatively, the temperature sensor can be fastened to the laminated glass pane from the outside or assigned to the laminated glass pane. Preferably, the temperature sensor is attached to the inside surface of the inner glass pane. The temperature sensor can also be arranged in the control unit itself or in a fastening element for fastening the control unit to the laminated glass pane. In principle, it is also possible to use a temperature sensor which is neither directly fastened to the laminated glass pane nor integrated therein but measures the temperature at a distance, for example an IR sensor which is arranged near the laminated glass pane and pointed toward the laminated glass pane.

[0059] In another advantageous embodiment, the control unit is adapted to determine the electrical impedance of the active layer and to determine therefrom the temperature of the laminated glass pane or, more precisely, of the functional element. This is possible because the impedance (equivalent to the conventional ohmic resistance in the case of AC voltage) is temperature-dependent. In particular, there is a monospatial relationship between the real part of the electrical impedance of the functional element and the temperature. In this way, a temperature can be assigned to each impedance. In particular, the real part of the impedance vs. temperature is strictly monotonically decreasing. The advantage of this embodiment is that a temperature sensor can be omitted, which must be integrated as an additional component and thus complicates the structure and increases the production costs.

[0060] Typically, above a certain limit temperature, memory effects and the temperature dependence of the switching behavior are very pronounced, while below this limit temperature, the temperature dependence changes less significantly. The limit temperature of ordinary functional elements is usually about 60° C. Higher temperatures occur in particular in strong sunlight. Therefore, in one development of the invention, the method can be carried out to determine the temperature and the method according to the invention is carried out only after a temperature above a previously defined limit temperature (e.g. 50° C. or 60° C.) has been reached.

[0061] The functional element according to the present invention is a PDLC (Polymer Dispersed Liquid Crystal) functional element. The active layer of the PDLC functional element contains liquid crystals embedded in a polymer matrix.

[0062] The functional element according to the present invention is preferably a standard PDLC functional element, which has maximum transmission and minimum opacity (clear transparent state) in the "on" switching state of applying voltage, and has minimum transmission and maximum opacity (opaque, non-transparent (diffuse) state) in the "off" switching state of cutting off the voltage. This means that if no voltage is applied to the planar electrodes, the liquid crystal will be aligned in a disordered manner, which leads to strong scattering of light passing through the active layer. If a voltage is applied to the planar electrodes, the liquid crystal will be aligned in a common direction and increase the transmittance of light passing through the active layer. However, other functional elements can also be used, the variability of its optical properties is based on liquid crystals, such as PNLC (polymer network liquid crystal) functional elements.

[0063] Alternatively, the functional element according to the invention is preferably an inverse PDLC functional element (also called reverse mode PDLC), which has maximum transmission and minimum opacity in the "off" switching state with the voltage turned off (clear transparent state) and has minimum transmission and maximum opacity in the "on" switching state with the voltage applied (opaque, non-transparent (diffuse) state). The teaching according to the invention applies accordingly.

[0064] The above-mentioned controllable PDLC functional elements and their operation modes are known per se to those skilled in the art, so a detailed description may be omitted at this point.

[0065] In an advantageous embodiment, the PDLC functional element comprises two carrier films in addition to the active layer and the planar electrodes, wherein the active layer and the planar electrodes are preferably arranged between the carrier films. The carrier film is preferably made of a thermoplastic material, for example based on polyethylene terephthalate (PET), polypropylene, polyvinyl chloride, fluorinated ethylene propylene, polyvinyl fluoride or ethylene tetrafluoroethylene, particularly preferably based on PET. The thickness of the carrier film is preferably 10 μm to 200 μm. Such a functional element can advantageously be provided as a multilayer film cut to size and shape, in particular purchased commercially, and then laminated into a laminated glass sheet, preferably via respective thermoplastic connecting layers with an outer glass sheet and an inner glass sheet. Even when the first planar electrode is incorporated into such a multilayer film, it can be segmented by laser radiation. Thin, visually inconspicuous insulating lines can be produced by laser processing without damaging the carrier film usually located above it.

[0066] The functional element can be sealed at its sides, for example by incorporating a carrier layer or by a (preferably polymeric) adhesive tape. The active layer can thus be protected, in particular from diffusion of components of the intermediate layer (in particular plasticizers) into the active layer, which could lead to degradation of the functional element.

[0067] For electrical contact, the planar electrodes or electrode segments are preferably connected to so-called flat conductors or foil conductors, which extend from the intermediate layer beyond the side edges of the laminated glass pane. The flat conductor has a strip-shaped metal layer as its conductive core, which, apart from the contact surface, is usually surrounded by a polymer insulating sheath. Optionally, so-called busbars, such as strips of conductive foil (e.g. copper foil) or conductive imprints, can be arranged on the planar electrodes, wherein the flat conductors or foil conductors are connected to the busbars. The flat conductors or foil conductors are connected to the control unit directly or via further conductors.

[0068] In an advantageous embodiment, the control unit is fastened to the inside surface of the inner glass pane facing away from the interlayer. The control unit can, for example, be attached directly to the surface of the inner glass pane. In an advantageous embodiment, the control unit is embedded in a fastening element, which is in turn fastened to the inside surface of the inner glass pane, preferably by means of an adhesive layer. Such fastening elements are also referred to as brackets in the automotive sector and are usually made of plastic. By attaching the control unit directly to the laminated glass pane, the electrical connection of the laminated glass pane is facilitated. In particular, no long cables are required between the control unit and the functional elements.

[0069] Alternatively, however, if the laminated glazing is a window glazing, the control unit may also not be attached to the laminated glazing but may, for example, be integrated in the electrical system of the vehicle or fastened to the vehicle body. The control unit is preferably arranged in the interior of the vehicle so that it is not visible, for example in the dashboard or behind a panelling.

[0070] Laminated glass panels can be provided with an opaque cover print, in particular in the peripheral edge region, which is common practice in the automotive sector, in particular for windshields, rear windows and roof panels. The cover print is usually made of an enamel containing glass frit and a pigment, in particular a black pigment. The printing ink is usually applied by screen printing and then fired. Such a cover print is applied to at least one glass panel surface, preferably the inner side surface of the outer glass panel and / or the inner glass panel. The cover print preferably surrounds the central perspective area in a frame-like manner and is particularly used to protect the adhesive that connects the laminated glass panel to the vehicle body from ultraviolet radiation. If a control unit is attached to the inner side surface of the inner glass panel, it is preferably attached in the opaque area of ​​the cover print.

[0071] Thermoplastic interlayers are used to connect two glass panes, which is common practice for laminating glass panes. Usually a thermoplastic film is used and the interlayer is formed from it. In a preferred embodiment, the interlayer is formed from at least a first thermoplastic layer and a second thermoplastic layer, between which the functional element is arranged. The functional element is then connected to the outer glass pane via the region of the first thermoplastic layer and to the inner glass pane via the region of the second thermoplastic layer. The thermoplastic layer preferably extends circumferentially beyond the functional element. Where the thermoplastic layers are in direct contact with each other without being separated from each other by the functional element, they can merge together during the lamination process so that the original layers can no longer be discerned but a homogeneous interlayer is present.

[0072] The thermoplastic layer can be formed, for example, from a single thermoplastic film. The thermoplastic layer can also be formed from sections of different thermoplastic films which are laterally connected to one another.

[0073] In a preferred embodiment, the functional element, more precisely, the side of the functional element, is surrounded circumferentially by the third thermoplastic layer. The third thermoplastic layer is frame-shaped with a groove, into which the functional element is inserted. The third thermoplastic layer can be formed by a thermoplastic film into which the groove has been introduced by cutting. Alternatively, the third thermoplastic layer can also be composed of a plurality of film segments surrounding the functional element. The intermediate layer is then formed by a total of at least three thermoplastic layers arranged flat on top of each other, wherein the central layer has a groove in which the functional element is arranged. During production, the third thermoplastic layer is arranged between the first and second thermoplastic layers, wherein the sides of all thermoplastic layers are preferably congruent. The third thermoplastic layer preferably has approximately the same thickness as the functional element. This compensates for the local thickness difference introduced by the locally limited functional element, so that glass breakage during the lamination process can be avoided and an improved visual appearance can be obtained.

[0074] The layers of the intermediate layer are preferably formed from the same material, but in principle can also be formed from different materials. The layers or films of the intermediate layer are preferably based on polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) or polyurethane (PU). This means that the layer or film mainly contains the material (greater than 50% by weight) and can optionally contain other ingredients, such as plasticizers, stabilizers, ultraviolet or infrared 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, a film with a standard thickness of 0.38 mm or 0.76 mm can be used.

[0075] As is common with window panes, the outer pane and the inner pane are preferably made of glass, particularly preferably soda-lime glass. However, the glass panes can also be made of other types of glass, for example quartz glass, borosilicate glass or aluminosilicate glass, or of hard transparent plastics, for example polycarbonate or polymethyl methacrylate. The glass panes can be transparent or also tinted or colored. Depending on the application, limits can be set to the degree of tinting or coloring: for example, it is sometimes necessary to ensure a specified light transmittance, for example a light transmittance of at least 70% in the main viewing area A in accordance with 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 on vehicles").

[0076] The outer pane, the inner pane and / or the intermediate layer may have suitable coatings known per se, such as anti-reflective coatings, non-stick coatings, scratch-resistant coatings, photocatalytic coatings, UV-absorbing or reflecting coatings or IR-absorbing or reflecting coatings, such as sunscreen coatings or low-E coatings.

[0077] The thickness of the outer pane and the inner pane can vary within a wide range and thus be adapted to the requirements of the individual case. The outer pane and the inner pane preferably have a thickness of 0.5 mm to 5 mm, particularly preferably 1 mm to 3 mm.

[0078] The invention also relates to the use of a glazing unit according to the invention, in particular a laminated glass pane of a glazing unit according to the invention, in a building or in a land, air or water vehicle, preferably as a window pane for a vehicle, in particular a motor vehicle. The glazing unit can be used, for example, as a windshield, roof, rear wall pane or side pane.

[0079] In a particularly preferred embodiment, the glazing unit or the laminated glass panel is a windshield of a vehicle. The functional element is preferably then used as an electrically controllable sun visor, which is arranged in the upper region of the windshield, while the majority of the windshield is not provided with the functional element. The switching zones are preferably arranged substantially parallel to the upper edge of the windshield and at increasing distances therefrom. Due to the independently switchable switching zones, the user can determine, depending on the position of the sun, the extent of the upper edge adjacent region to be shaded or to provide a high light scattering in order to avoid sun glare.

[0080] In another preferred embodiment, the glazing unit or the laminated glass sheet is a roof panel of a vehicle. The functional element is preferably arranged in the entire perspective area of ​​the laminated glass sheet. In a typical embodiment, the perspective area includes the laminated glass sheet minus a peripheral edge area, which is provided with an opaque covering mark on at least one surface of the glass sheet. The functional element extends over the entire perspective area, wherein its side is arranged in the area of ​​the opaque covering mark and is therefore invisible to the observer. The switching zone is preferably arranged substantially parallel to the leading edge of the roof panel and at an increasing distance therefrom. The user can define which area of ​​the roof panel is transparent, which area should be shaded or provide high light scattering, for example, according to the position of the sun, to avoid overheating in the interior of the vehicle by means of independently switchable switching zones. It is also possible to assign a switching zone located above it to each vehicle occupant, i.e., for example, the driver, the front occupant, the left rear occupant, and the right rear occupant.

[0081] The invention is explained in more detail with reference to the accompanying drawings and exemplary embodiments. The drawings are schematic representations and are not drawn to scale. The drawings do not limit the invention in any way. In the drawings:

[0082] Figure 1 A plan view showing an embodiment of a glazing unit according to the invention;

[0083] Figure 2 Show Through Figure 1 cross-section of a glazing unit;

[0084] Figure 3 show Figure 2 A magnified view of the Z region;

[0085] Figure 4 Display as an equivalent circuit diagram Figure 1 PDLC functional components of the glazed units;

[0086] Figure 5 a), b) Schematic diagrams showing the switching behavior of a PDLC functional element in a method according to the prior art;

[0087] Figure 6a)-c) Schematic diagrams showing the switching behavior of a PDLC functional element in the method according to the present invention;

[0088] Figure 7 a)-c) schematic diagrams showing a typical application example; and

[0089] Figure 8 a), b) Schematic diagram showing another typical application example.

[0090] Figure 1 , Figure 2 , Figure 3 and Figure 4 Each shows a detail of a glazing unit 100 according to the invention, which contains a PDLC functional element 4 with electrically controllable optical properties. The glazing unit 100 comprises a laminated glass pane, which is provided, for example, as a roof pane of a passenger car, whose optical properties in certain areas, such as light transmission or light scattering, can be electrically controlled. The laminated glass pane comprises an outer glass pane 1 and an inner glass pane 2, which are connected to each other via an intermediate layer 3. The outer glass pane 1 and the inner glass pane 2 consist, for example, of soda-lime glass, which may be optionally tinted. The outer glass pane 1 has, for example, a thickness of 2.1 mm, while the inner glass pane 2 has a thickness of 1.6 mm.

[0091] The intermediate layer 3 comprises, for example, a total of three thermoplastic layers 3a, 3b, 3c, each of which is formed by a PVB thermoplastic film having a thickness of 0.38 mm. The first thermoplastic layer 3a is connected to the outer glass plate 1, and the second thermoplastic layer 3b is connected to the inner glass plate 2. The third thermoplastic layer 3c located between them has a cutout, and the PDLC functional element 4 is embedded therein with a substantially accurate fit, i.e., roughly flush on all sides. The third thermoplastic layer 3c thus forms a kind of base or frame for the functional element 4 of approximately 0.4 mm thickness, and the functional element 4 is thus encapsulated by the thermoplastic material and thus protected. The PDLC functional element 4 is, for example, a PDLC multilayer film that can be switched from a clear and transparent state to a non-transparent (diffuse) state that is opaque.

[0092] Here, the PDLC multilayer film is, for example, a standard PDLC multilayer film, which has maximum transmittance and minimum opacity (clear transparent state) in the "on" switching state with applied voltage, and has minimum transmittance and maximum opacity (opaque, non-transparent (diffuse) state) in the "off" switching state with cut off voltage.

[0093] The PDLC functional element 4 is a multilayer film consisting of an active layer 5 and two carrier films 6, 7 between two planar electrodes 8, 9. The active layer 5 contains a polymer matrix in which liquid crystals are dispersed, and the liquid crystals are aligned according to the voltage applied to the planar electrodes 8, 9, thereby adjusting the optical properties. The carrier films 6, 7 are made of PET and have a thickness of, for example, 0.125 mm. The carrier films 6, 7 are provided with an ITO coating facing the active layer 5 and having a thickness of about 100 nm, the coating forming the planar electrodes 8, 9. The planar electrodes 8, 9 are connected to the cable 14 via a bus bar (not shown) (for example, formed by a copper foil tape), which produces an electrical connection with the control unit 10.

[0094] The control unit 10 is attached, for example, to the inner side surface of the inner glass pane 2 facing away from the interlayer 3. For this purpose, for example, a fastening element (not shown) is glued to the inner glass pane 2, in which the control unit 10 is embedded. However, the control unit 10 does not necessarily have to be attached directly to the laminated glass pane. Alternatively, it can be attached, for example, to the dashboard or the body, or can be integrated into the on-board electrical system of the vehicle.

[0095] The laminated glass pane has a circumferential edge region with an opaque cover mark 13. Such a cover mark 13 is usually formed by a black enamel. It is printed as a printing ink with black pigment and glass frit in a screen printing method and is fired into the glass pane surface. The cover mark 13 is applied, for example, to the inner side surface of the outer glass pane 1 and to the inner side surface of the inner glass pane 2. The side edges of the functional element 4 are covered by this cover mark 13. The control unit 10 is arranged in this opaque edge region, i.e., is glued to the cover mark 13 of the inner glass pane 2. The control unit 10 does not interfere with the view through the laminated glass pane and is visually inconspicuous. In addition, it is at a short distance from the side edge of the laminated glass pane, so that advantageously only a short cable 14 is required for the electrical connection of the functional element 14.

[0096] On the other hand, the control unit 10 is connected to the vehicle's onboard electrical system and, for simplicity, is described in Figure 1 and Figure 2 The control unit 10 is adapted to apply the voltage required for the desired optical state ("on" / "off" switching state) of the PDLC functional element 4 to the planar electrodes 8, 9 of the PDLC functional element 4 according to a switching signal specified by the driver, for example by pressing a button.

[0097] The laminated glass pane has, for example, four independent switching zones S1, S2, S3, S4, in which the switching states of the PDLC functional elements 4 can be set independently of each other by the control unit 10. The switching zones S1, S2, S3, S4 are arranged one after another in the direction from the leading edge to the trailing edge of the top plate, wherein the terms "leading edge" and "trailing edge" relate to the driving direction of the vehicle. With the aid of the switching zones S1, S2, S3, S4, the vehicle driver can choose (for example, depending on the position of the sun) to provide a diffuse state only to one area of ​​the laminated glass pane instead of the entire laminated glass pane, while other areas remain transparent.

[0098] In order to form the switching zones S1, S2, S3, S4, the first planar electrode 8 is interrupted by three insulating 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 insulating lines 8' are usually introduced into the first planar electrode 8 by laser processing and the first planar electrode 8 is subdivided into four electrode segments 8.1, 8.2, 8.3 and 8.4 which are substantially separated from one another. The respective electrode segments 8.1, 8.2, 8.3 and 8.4 are connected to a control unit 10 independently of one another. The control unit is suitable for applying voltages independently of one another between the respective 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 section of the active layer 5 located therebetween is subjected to the required voltage to achieve the desired switching state.

[0099] like Figure 4 As shown in the equivalent circuit diagram of , the control unit 10 is connected to a voltage source 15 via the on-board electrical system of the vehicle. In the field of vehicles, the voltage source 15 generally provides a DC voltage in the range of 12V to 14V (the on-board voltage of the vehicle). The control unit 10 is, for example, equipped with a DC-DC converter 11, which converts the on-board voltage (primary voltage) into a DC voltage of a higher magnitude, such as 65V (secondary voltage). The secondary voltage must be high enough to achieve 100% of the switching states of the PDLC functional element 4. The control unit 10 is also equipped with an inverter 12 that 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 pole, the inverter 12 has several independent outputs, each of which is connected to the electrode segments 8.1, 8.2, 8.3 and 8.4 in each case with one of the independent outputs, so that the switching states of the relevant switching zones S1, S2, S3, S4 can be set independently of each other.

[0100] In the case of a switching state of 0% ("off"), the electrode segments 8.1, 8.2, 8.3, 8.4 and the second planar electrode 9 always have the same potential, so that no voltage is applied. In the case of a switching state of the switching zones S1, S2, S3, S4 greater than 0% ("on"), a voltage is applied between the relevant electrode segments 8.1, 8.2, 8.3, 8.4 and the second planar electrode 9. Due to the voltage, a current flows through the relevant segment of the active layer 5.

[0101] Figure 5 a) and b) show schematic diagrams of the switching behavior of the PDLC functional element 4 in a method according to the prior art. In this comparative example according to the prior art, the glazing unit 100 has nine adjacent and independently switchable switching zones (S1-S9), which are connected to a control unit 10 (not shown here) (e.g. according to Figure 1-4 principle).

[0102] Figure 5 a) Display of alternating switching states, i.e. adjacent switching zones (electrode segments) have different switching states. For example, the switching zones S1, S3, S5, S7 and S9 have an "off" switching state, which corresponds, for example, to the maximum diffusivity (opacity or scattering) of the line of sight through the PDLC functional element 4 in the respective switching zones S1, S3, S5, S7 and S9. The immediately adjacent switching zones S2, S4, S6 and S8, which are separated from each other only by a separation line 8' (not shown in detail here) between the electrode segments 8.1-8.9, have an "on" switching state, which corresponds, for example, to the minimum diffuse transparency (i.e., maximum clarity).

[0103] Figure 5 b): If now all switching zones S1-S9 are switched directly to the "off" switching state by changing the "on" switching state of the switching zones S2, S4, S6 and S8, it is obvious that the switching zones S2, S4, S6 and S8, which have changed their switching state from "on" to "off", achieve a lower diffusivity than the switching zones S1, S3, S5, S7 and S9, which have been in the "off" switching state for some time and can therefore have a different switching history and a different temperature history. This effect can be referred to as the above-mentioned memory effect and increases in severity as the temperature of the PDLC functional element 4 increases. The resulting difference is not very aesthetic and can, for example, lead to glare for the driver or other passengers in vehicle glazing.

[0104] In other words, the teaching of the present invention can be described as follows: If a switching zone of a PDLC functional element 4, for example a switching zone in the "off" switching state, is heated from room temperature to a temperature of, for example, 60° C. and then cooled again, the transparency of the "new" "off" switching state is different from the "old" "off" switching state before passing through this temperature distribution. If this switching zone of the PDLC functional element 4 is subsequently switched on ("on") and switched off ("off") again, the first "off" switching state is restored, which corresponds to the "fresh" memory state. It is therefore always desirable to ensure this "fresh" memory state ("off" switching state) as soon as adjacent switching zones are switched on and switched off again, because they are inevitably in said "fresh" memory state after having been switched off.

[0105] Figure 6 a) and b) are schematic diagrams showing the switching behavior of the PDLC functional element 4 when the method according to the invention is applied. The glazing unit 100 according to this example of the invention corresponds in its basic structure to the glazing unit according to the invention. Figure 5 The glazing unit of the comparative example of the prior art is therefore referred to Figure 5 The following description.

[0106] Figure 6 a), similar to Figure 5 a), showing alternating switching states, i.e. adjacent switching zones have different switching states. For example, the switching zones S1, S3, S5, S7 and S9 have an "off" switching state, which corresponds, for example, to a maximum diffusivity (opacity or scattering) of the line of sight through the PDLC functional element 4 in the respective switching zones S1, S3, S5, S7 and S9. The immediately adjacent switching zones S2, S4, S6 and S8, which are separated from each other only by a separation line 8' (not shown in detail here) between the electrode segments 8.1-8.9, have an "on" switching state, which corresponds, for example, to a minimum diffuse transparency (i.e., maximum clarity).

[0107] Different from Figure 5 In the comparative example of the prior art in a) and b), when changing the switching state of each switching zone, all the switching states of the switching zones S1-S9 are initially set to the "on" switching state, for example, for a time t of 0.5 seconds (see Figure 6 b)). Subsequently, all switching zones S1 - S9 are set to the “off” switching state, for example by applying suitable control voltages via the control unit 10 .

[0108] like Figure 6 As can be seen in c), all switching zones S1-S9 have the same optical properties, especially the same diffusion rate, regardless of whether they are initially in the "on" switching state (such as switching zones S2, S4, S6, S8) or already in the "off" switching state (such as switching zones S1, S3, S5, S7, S9).

[0109] This creates a uniform line of sight with little glare for the driver or other passengers. Regardless of the temperature T of the PDLC functional element 4, this can be effectively avoided. Figure 5 The memory effect described in a) and b).

[0110] As mentioned above, the memory effect always occurs to some extent, especially at temperatures above, for example, 50°C.

[0111] Without limiting the invention, this effect is particularly evident in the following constellation:

[0112] Depending on the varying temperature of the glazing unit 100 in different application scenarios, the optical properties in the switched-off state may change during operation or between two uses (morning / evening, next day). Figure 7 a)-c) show the scenes during vehicle operation. Figure 8 a)-b) show the scene between two uses.

[0113] Figure 7 a)-c) schematically show the initial situation of a vehicle parked in a garage. Figure 7 In a), the vehicle is parked in a (relatively cool) garage; the glazing unit 100 with the PDLC functional element 4 is in the "off" switching state, ie it is de-energized and therefore in the diffusing state.

[0114] Figure 7 b) shows a glazing unit 100 with alternating "on" / "off" switching zones. The glazing unit 100 is subsequently heated to more than 60° C., for example under the influence of sunlight and with only a slight breeze in city traffic, for a period of, for example, approximately 2 hours.

[0115] Figure 7 c) Shows the glazing unit under the influence of temperature, where the diffuse transparency of the switching zone, which has now been “switched off” for a long time, is higher than at Figure 7 b) after a short switch-on time and a colder state. Figure 7 c) Now for example corresponding to the comparative example according to the prior art Figure 5 a) or according to an example of the present invention Figure 6 a) Initial state.

[0116] By applying the method according to the invention, homogeneous optical properties are obtained over the entire surface of the switching zone.

[0117] Figure 8 a) and b) schematically show another initial situation using an example of a vehicle parked in the sun. Figure 8In a), the glazing unit 100 is cool and in the "off" switching state, ie it is de-energized and therefore in a diffuse state.

[0118] Figure 8 b) shows the glazing unit 100 after a standing time of approximately 2 hours and after being heated by sunlight to, for example, more than 60° C. Figure 8 b) shows the glazing unit 100 after it has been subjected to a temperature change. The diffuse transparency of the switching zone, which has now been "switched off" for a long time, is higher than Figure 8 The temperature in a) affects the previous state.

[0119] If now a glazing unit 100 is applied with Figure 5 a) or 6a), and if it were immediately switched back to completely "off" (without an intermediate "on" switching state) according to the prior art, a switching mode according to Figure 5 b). The switching zones S1, S3, S5, S7, S9 which are not "switched on" remain more diffuse than the switching zones S2, S4, S6, S8 which are "switched on" and then "switched off" again, because the memory state is now restored in these latter switching zones.

[0120] All switching zones are switched “on” according to the invention (e.g. Figure 6 b) restores the memory state of the PDLC functional element, resulting in a uniform optical diffuseness across the entire surface of the switching zone when all switching zones are subsequently "switched off" (see Figure 6 c).

[0121] Reference numerals:

[0122] 1 Outer glass panel

[0123] 2 Inner glass panels

[0124] 3 Thermoplastic middle layer

[0125] 3a The first layer of the middle layer 3

[0126] 3b The second layer of the middle layer 3

[0127] 3c The third layer of the middle layer 3

[0128] 4 PDLC functional elements, functional elements with electrically controllable optical properties

[0129] 5 Active layer of functional element 4

[0130] 6 First carrier film of functional element 4

[0131] 7 Second carrier film of functional element 4

[0132] 8 First planar electrode of functional element 4

[0133] 8.1, 8.2, 8.3, 8.4 Electrode segments of the first planar electrode 8

[0134] 8' Isolation line between two electrode segments 8.1, 8.2, 8.3, 8.4

[0135] 9 Second planar electrode of functional element 4

[0136] 10 Control unit

[0137] 11 DC-DC Converter

[0138] 12 Inverter

[0139] 13 Covering the mark

[0140] 14 Cable

[0141] 15 Voltage source / DC voltage source

[0142] 100 glazing units

[0143] S1, S2, S3, S4, S5, S6, S7, S8, S9, Sn, Sn+1 switching area n is a natural number

[0144] t Duration

[0145] T Temperature

[0146] X-X' hatch line

[0147] Z magnified area

[0148] On / off switching state

Claims

1. A method for controlling a PDLC functional element (4) having at least two adjacent, independently switchable switching zones (Sn, Sn+1, where n=1 . . . 8), wherein a switching state (on, off) can be applied to the switching zones (Sn, Sn+1) by means of a control unit (10), wherein A) applying different switching states (on, off) to at least two adjacent switching regions (Sn, Sn+1); B) a user or an automatic control device sends a signal to a control unit (10) to change the switching state (on, off) in each switching area (Sn, Sn+1); C) first setting all switching zones (S1, S2, S3, S4, S5, S6, S7, S8, S9) to the "on" switching state; and D) The changed switching state is then applied to the switching zones ( S1 , S2 , S3 , S4 , S5 , S6 , S7 , S8 , S9 ).

2. The method according to claim 1, wherein in step C the “on” switching state is applied simultaneously in all switching zones (S1, S2, S3, S4, S5, S6, S7, S8, S9).

3. A method according to claim 1, wherein in step C the "on" switching state is applied in the switching zones (S1, S2, S3, S4, S5, S6, S7, S8, S9) at different times, preferably in a rolling function or an alternating sequence, and in particular, step D is performed only after each switching zone (S1, S2, S3, S4, S5, S6, S7, S8, S9) has been set to the "on" switching state at least once.

4. The method according to any one of claims 1 to 3, wherein in step C the "on" switching state is maintained in the switching zone (S1, S2, S3, S4, S5, S6, S7, S8, S9) for a time t greater than or equal to 1 / 60s, preferably greater than or equal to 0.5s, in particular 0.5s to 10s. 5 . The method according to claim 1 , wherein the method is performed again if, in step D, different switching states (on, off) are applied to at least two adjacent switching zones (Sn, Sn+1).

6. The method according to any one of claims 1 to 5, wherein the temperature T of the PDLC functional element (4) is determined and steps AD are performed only when the temperature T is greater than 40°C, preferably greater than 50°C, and particularly preferably greater than 60°C, and / or the temperature T of the PDLC functional element (4) is determined and steps A to D are performed only when a temperature distribution is passed in which the temperature T is greater than 40°C, preferably greater than 50°C, and particularly preferably greater than 60°C at a certain point in time after the "on" switching state is last applied to the PDLC functional element (4).

7. A glazing unit (100) having a PDLC functional element (4), the glazing unit comprising A laminated glass panel (101) comprising: - an outer pane (1) and an inner pane (2), which are connected to one another via at least one thermoplastic intermediate layer (3); - a PDLC functional element (4) having at least two adjacent, independently switchable switching zones (Sn, Sn+1, where n=1 . . . 8), which is arranged between an outer glass pane (1) and an inner glass pane (2), wherein - the PDLC functional element (4) has at least two adjacent, independently switchable switching zones (Sn, Sn+1, where n=1...8), and a control unit (10) for electrically controlling the optical properties of the switching zones (S1, S2, S3, S4, S5, S6, S7, S8, S9) of the PDLC functional element (4), The control unit (10) is provided to carry out the method according to one of claims 1 to 6.

8. The glazing unit (100) according to claim 7, wherein the PDLC functional element (4) has an active layer (5) with electrically controllable optical properties between a first planar electrode (8) and a second planar electrode (9), and the first planar electrode (8) is divided into at least two separate electrode segments (8.1, 8.2, 8.3, 8.4) by at least one isolating line (8'), wherein each electrode segment (8.1, 8.2, 8.3, 8.4) forms an independently switchable switching zone (Sn, Sn+1, where n=1...8).

9. An assembled glazing unit (100) according to claim 8, wherein the electrode segments (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and the second planar electrode (9) are electrically connected to a control unit (10) so that voltages can be applied independently between the electrode segments (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and the second planar electrode (9) to control the optical properties of the active layer (5) segment located therebetween.

10. The glazing unit (100) according to claim 8, wherein the second planar electrode (9) has no isolating lines (8') or has a smaller number of isolating lines (8') and thus a smaller number of electrode segments than the first planar electrode (8) to assign several electrode segments (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) to at least one electrode segment of the second planar electrode (9).

11. The glazing unit according to claim 7 , wherein the laminated glass pane is equipped with a temperature sensor which is connected to a control unit ( 10 ) such that the control unit ( 10 ) can determine the temperature of the laminated glass pane with the aid of the temperature sensor, or the control unit ( 10 ) is adapted to determine the electrical impedance of the active layer ( 5 ) and to determine the temperature of the laminated glass pane therefrom. 12 . The glazing unit according to claim 7 , wherein the at least one separating line ( 8 ′) has a width of 5 μm to 500 μm, in particular a width of 20 μm to 200 μm.

13. A vehicle, in particular a passenger vehicle, comprising a laminated glass pane (100) according to one of claims 7 to 12.

14. Use of the method according to one of claims 1 to 6 for controlling a PDLC functional element (4) in a glazing unit (100), preferably as a window pane of a vehicle, in particular as a windshield or roof pane.

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