Method for controlling a PDLC functional element having multiple independently switchable switching regions

Abstract

An improved method for controlling PDLC functional elements is provided. The present invention relates to a method for controlling a PDLC functional element having at least two adjacent, independently switchable switching areas (Sn, Sn+1, n=1 to 8), in which a switching state (on, off) can be applied to the switching areas (Sn, Sn+1) by a control unit, A) applying different switching states (on, off) to at least two adjacent switching areas (Sn, Sn+1), B) sending signals to the control unit by a user or automatic control to change the switching states (on, off) in the individual switching areas (Sn, Sn+1), C) first setting all switching areas (S1, S2, S3, S4, S5, S6, S7, S8, S9) to an "on" switching state, and D) then applying the changed switching states to the switching areas (S1, S2, S3, S4, S5, S6, S7, S8, S9).

Description

[Technical Field]

[0001] The present invention relates to a method for controlling a PDLC functional element having multiple independently switchable switching areas, a glazing unit and uses thereof. [Background technology]

[0002] Glazing units with electrically controllable optical properties are known. They comprise laminated panes with functional elements whose optical properties can be changed by applying a voltage. The voltage is applied through 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 EP 0 876 608 A1 and WO 2011 033 313 A1. 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 10 2008 026 339 A1. The active layer contains liquid crystals embedded in a polymer matrix. In the "off" switching state, when no voltage is applied, the liquid crystals are disordered, resulting in strong scattering of light passing through the active layer. In the "on" switching state, applying a voltage to the planar electrodes causes the liquid crystals to align in a common direction, increasing the transmittance of light through the active layer. In this way, PDLC functional elements operate primarily by increasing scattering rather than reducing total transmittance, thereby preventing clear vision and ensuring anti-glare. Electrochromic functional elements are also known from, for example, U.S. Patent Application Publication No. 20120026573, WO 2010147494, EP 1862849, and WO 2012007334, in which the change in transmittance occurs as a result of an electrochemical process induced by an applied voltage.

[0003] Such glazing units can be used, for example, as windowpanes for vehicles, and their optical properties can be electrically controlled. They can also be used, for example, as roofpanes to reduce exposure to direct sunlight and annoying reflections. Such roofpanes are known, for example, from German Patent Application Publication No. 10043141 and European Patent Application Publication No. 3456913. Windshields in which electrically controllable sunscreens are realized by switchable functional elements have also been proposed to replace conventional mechanically foldable sunscreens in motorized vehicles. 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 glazing units with multiple switching areas or switchable functional elements within the glazing unit, whose optical properties can be switched independently of one another. For example, one area of ​​the functional element can be selectively darkened or provided with a high level of light scattering, while other areas remain clear or transparent. Glazing units with independent switching areas and methods for their manufacture are known, for example, from German Utility Model No. 202021105089, WO 2014072137, or WO 2017157626.

[0005] Independent switching regions are typically formed by further dividing one of the planar electrodes into individual switching regions (electrode segments) by separation lines. These switching regions (electrode segments) are isolated from each other and connected to a control unit independently, allowing for independent control, while the other planar electrode, for example, does not have any separation lines. Separation lines are typically introduced into the planar electrode by laser machining. Since the planar electrode must be transparent to ensure the transparency of the laminated pane, it is not possible to select the planar electrode in terms of optimal electrical conductivity. ITO layers, which have low electrical conductivity or high electrical resistance, are commonly used as planar electrodes.

[0006] An electrical control unit for controlling a functional element having electrically controllable optical properties is known, for example, from EP 3910412 A1. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] European Patent No. 0876608 [Patent Document 2] International Publication No. 2011033313 [Patent Document 3] German Patent Application Publication No. 102008026339 [Patent Document 4] US Patent Application Publication No. 20120026573 [Patent Document 5] International Publication No. 2010147494 [Patent Document 6] European Patent Application Publication No. 1862849 [Patent Document 7] International Publication No. 2012007334 [Patent Document 8] DE 10043141 A1 [Patent Document 9] German Patent Application Publication No. 102013001334 [Patent Document 10] German patent number 102005049081 [Patent Document 11] German Patent Application Publication No. 102005007427 [Patent Document 12] German Patent Application Publication No. 102007027296 [Patent Document 13] German Utility Model No. 202021105089 [Patent Document 14] International Publication No. 2014072137 [Patent Document 15] International Publication No. 2017157626 [Patent Document 16] European Patent Application Publication No. 3910412 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention is based on the object of providing an improved method for controlling a PDLC functional element having at least two adjacent, independently switchable switching areas. [Means for solving the problem]

[0009] This object is, according to the invention, a method for controlling a PDLC functional element having at least two adjacent independently switchable switching areas, the method comprising the steps of: applying a switching state (on, off) to the switching areas by a control unit; A) applying different switching states (on, off) to at least two adjacent switching regions; B) sending a signal to the control unit by the user or by automatic control to change the switching state (on, off) of the individual switching areas; C) First, set all switching regions to the "ON" switching state, D) then applying the changed switching state to the switching region; This is achieved by the method.

[0010] It should be understood that in step D) the switching regions that are set to "on" can remain "on".

[0011] The method according to the invention is characterized in that in an (intermediate) step C all switching regions are set to a uniform "on" switching state and then a new distribution of switching states is applied to the switching regions, which restores the original memory state of the different switching states in the switching regions and causes all switching regions to once again exhibit the same optical properties.

[0012] In an advantageous embodiment of the method according to the invention, in step C, the "on" switching state is applied simultaneously to all switching regions.

[0013] In one advantageous embodiment of the method according to the invention, in step C, the "on" switching state is applied to the switching regions at different times. Preferably, the "on" switching state is applied to the switching regions in a rolling manner, i.e., by switching on ("on" switching state) for example from one side of the PDLC functional element to the other side, and particularly preferably back again, in a succession of individual switching regions. It should be understood that this process can be carried out several times in succession.

[0014] Alternatively, the switching regions can be switched in an alternating sequence. For example, in a glazing with nine switching regions, the first, third, fifth, seventh, and ninth switching regions can be switched "on" first, then switched "off" alternately with the second, fourth, sixth, and eighth switching regions.

[0015] It should be understood that further sequences can be switched, for example, successively from opposite sides towards the centre, i.e., in the example with nine switching regions described above, starting with the first and ninth switching regions, then the second and eighth switching regions, then the third and seventh switching regions, then the fourth and sixth switching regions, and finally the fifth switching region in the centre.

[0016] In an advantageous embodiment of the method according to the invention, step D is carried out only after each switching region has been set to the "on" switching state at least once.

[0017] In another advantageous embodiment of the method according to the invention, in step C, the "on" switching state is maintained in the switching region for a period t of at least 1 / 60 s, preferably at least 0.5 s, in particular 0.5 s to 10 s, which ensures an almost complete restoration of the memory state and thus a sufficient homogenization of the optical properties of the switching region.

[0018] This object is furthermore provided, according to the invention, by a glazing unit comprising a PDLC functional element, the glazing unit comprising: ·below: - an outer pane and an inner pane connected to each other by at least one thermoplastic intermediate layer; a PDLC functional element having at least two adjacent independently switchable switching regions, the PDLC functional element being disposed between an outer pane and an inner pane, wherein: - a PDLC functional element having at least two adjacent independently switchable switching regions; Laminated panes with and a control unit for electrically controlling the optical properties of the switching areas of a PDLC functional element, the control unit being provided for carrying out the method according to the invention; This is achieved by a glazing unit comprising:

[0019] In one advantageous embodiment, the glazing unit according to the invention comprises a laminated pane, the laminated pane comprising an outer pane and an inner pane connected to each other by a thermoplastic interlayer, and an electrically controllable functional element arranged between the outer pane and the inner pane, the functional element comprising an active layer having electrically controllable optical properties between a first planar electrode and a second planar electrode, and a control unit configured to control the optical properties of the functional element.

[0020] 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, the first planar electrode being advantageously divided by at least one separating line into at least two separate electrode segments, each electrode segment forming an independently switchable switching region.

[0021] In another advantageous embodiment, each electrode segment of the first planar electrode and the second planar electrode are electrically connected to a control unit, making it possible to apply voltages between each electrode segment of the first planar electrode and the second planar electrode independently of one another, thereby controlling the optical properties of the section of the active layer located therebetween.

[0022] In another advantageous embodiment, the second planar electrode has no separating lines or has fewer separating lines and therefore fewer electrode segments than the first planar electrode, so that at least one electrode segment of the second planar electrode is assigned to multiple electrode segments of the first planar electrode.

[0023] The present invention is based on the finding that the switching behavior and optical properties, such as diffusivity and transmittance, of a typical PDLC functional element depend on its switching. The method and glazing unit prevent deviations in the optical properties of a PDLC functional element in its switched-off state ("off" switching state). These deviations are caused by the so-called "memory effect" of the PDLC functional element. This memory effect is the visual effect of a switching region (electrode segment) that has recently been switched on ("on" switching state) having a different opacity and / or scattering behavior in its subsequently switched-off state ("off" switching state) from an adjacent PDLC switching region that has been switched off for a very long time ("off" switching state) and / or has a different switching history.

[0024] This can be remedied by briefly switching all switching regions on ("on" switching state), which restores the original memory state and uniformizes the optical properties.

[0025] For example, in a standard PDLC functional element, if all odd-numbered switching areas of a glazing unit designed as a roof pane with nine switching areas are switched on for five minutes and then the entire roof is switched off (opaque), passengers inside the vehicle will clearly notice a difference in opacity between the odd-numbered and even-numbered switching areas. To prevent this unsatisfactory experience for customers, various measures can be implemented at the system level, such as introducing a uniforming sequence after a given switching operation (e.g., switching all switching areas in a rolling manner); introducing a start and end sequence; or simultaneously switching all switching areas on and off. In other words, to achieve uniform optical properties, each switching area must be periodically switched to maintain all switching areas in an equally opaque or equally transparent state.

[0026] The glazing unit and the method are described together below, but the descriptions 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 also 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 implemented accordingly.

[0027] The laminated pane according to the invention, in particular as part of a glazing unit according to the invention, comprises at least one outer pane and one inner pane connected to each other by at least one thermoplastic interlayer. The laminated pane is installed in a window opening (in particular a window opening or roof opening of a vehicle, or also a window opening of a building or room) for the purpose of separating the interior space from the exterior environment. In the context of the present invention, the term "inner pane" is understood to mean the pane facing the interior space. The outer pane means the pane facing the exterior environment. The outer pane and the inner pane each have an outer surface, an interior surface, and peripheral side edge surfaces extending therebetween. In the sense of the present invention, the outer surface means the major surface intended to face the exterior environment when installed. In the sense of the present invention, the interior surface means the major surface intended to face the interior of the room when installed. The interior surface of the outer pane and the outer surface of the inner pane face each other and are connected to each other by a thermoplastic interlayer.

[0028] The laminated pane according to the present invention comprises a PDLC functional element with electrically controllable optical properties, which is disposed between the outer and inner panes, i.e., embedded in the intermediate layer. The functional element is preferably disposed between at least two layers of thermoplastic material in the intermediate layer, with the functional element connected to the outer pane via a first layer and to the inner pane via a second layer. However, it is also possible to dispose the functional element 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 completely to the side edges of the laminated pane and therefore does not come into contact with the ambient atmosphere.

[0029] A PDLC functional element comprises at least one active layer and two planar electrodes arranged on either side of the active layer, such that the active layer is disposed between the planar electrodes. The planar electrodes and the active layer are typically arranged substantially parallel to the surfaces of the outer and inner panes. The active layer has variable optical properties that can be controlled by applying a voltage to the active layer through the planar electrodes. In the context of the present invention, an electrically controllable optical property is understood to mean, in particular, a continuously controllable property. In the context of the present invention, the switching state of the functional element refers to the degree to which the optical property is changed compared to a voltage-free state. A 0% switching state corresponds to a voltage-free state, while a 100% switching state corresponds to the maximum change in the optical property. By appropriately selecting the voltage between the two states, all switching states can be continuously realized. A 20% switching state corresponds, for example, to a change in the optical property by 20% of the maximum change. The optical property particularly relates to light transmittance and / or scattering behavior.

[0030] However, in principle, it is conceivable that the electrically controllable optical property can be switched between only two clearly distinct states, where there are only two switching states, say 0% (off) and say 100% (on).It is also conceivable that the electrically controllable optical property can be switched between three or more clearly distinct states.

[0031] The planar electrode is preferably transparent, which in the context of the present invention means that the planar electrode has a light transmittance of at least 50%, preferably at least 70%, and particularly preferably at least 80% in the visible spectral range. The planar electrode preferably comprises at least one metal, metal alloy, or transparent conductive oxide (TCO). The planar electrode can 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 electrode preferably has a thickness of 10 nm to 2 μm, particularly preferably 20 nm to 1 μm, and very particularly preferably 30 nm to 500 nm.

[0032] According to the present invention, the first planar electrode has at least two segments (electrode segments) separated from each other by a separating line. A separating line is understood to mean a linear region within which the material of the planar electrode is absent, resulting in physical separation and therefore electrical isolation between adjacent segments. That is, there is no direct electrical connection between the electrode segments, but the electrode segments can be indirectly connected to each other, to some extent, electrically conductively, through the active layer adjacent to the electrode segments. The first planar electrode can be further divided into multiple segments by separating lines. Each electrode segment forms a switching region of the glazing device. The number of electrode segments can be freely selected by those skilled in the art according to individual needs. In a preferred embodiment, the separating lines extend substantially parallel to each other and from one side edge of the planar electrode to the opposite side edge. However, any other geometric shape is also conceivable.

[0033] Two electrode segments separated by only one separation line form adjacent switching regions within the meaning of the present invention, and may also be referred to as immediately adjacent switching regions.

[0034] The separating lines have a width of, for example, 5 μm to 500 μm, in particular 20 μm to 200 μm. The separating lines are preferably introduced into the planar electrode by laser irradiation. Those skilled in the art can appropriately select the width of the segments, i.e., the distance between adjacent separating lines, depending on the requirements of each individual case.

[0035] The second planar electrode and the active layer preferably each form a single, integral layer that is not further divided into segments by separating lines. However, in principle, the second planar electrode may be less segmented than the first planar electrode, i.e., have fewer separating 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. Crosstalk problems still occur in this case, but can be reduced by the approach according to the present invention. The separating lines of the second planar electrode are aligned with the separating lines of the first planar electrode in the line of sight through the laminated pane.

[0036] Because the electrode segments of the first planar electrode are electrically connected to the control unit independently of one another, a first potential (which is variable over time in the case of an AC voltage) can be applied to each electrode segment (regardless of the other electrode segments), which is referred to as a switching potential in the context of the present invention. Because the second planar electrode is also electrically connected to the control unit, 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 context of the present invention. If the first and second potentials are identical, no voltage is applied between the electrodes in the respective switching regions (off switching state, 0%). If the first and second potentials are different, a voltage is applied between the electrodes in the respective switching regions, thereby resulting in a finite switching state.

[0037] In one variant of the invention, the second planar electrode is also segmented, but to a lesser extent than the first, 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 independently to the control unit, so that a second potential (reference potential, "ground") can be applied to each electrode segment (independently of the other electrode segments). However, there is at least one electrode segment of the second planar electrode, which provides a reference potential for several switching areas. These switching areas can be controlled independently of one another, such that switching potentials can be applied independently to the electrode segments of the first planar electrode, while a single reference potential is applied to these electrode segments of the second planar electrode.

[0038] A control unit is provided and suitable for controlling the optical properties of the PDLC functional element. The control unit is conductively connected to the planar electrodes of the functional element on the one hand and to a power supply on the other hand. The control unit includes the electrical and / or electronic components necessary to apply the required voltage to the planar electrodes depending on the switching state. The switching state can be predetermined by a user (e.g., by operating a switch, button, or rotary or sliding controller), detected by a sensor, and / or transmitted via a digital interface from a central control device of the vehicle (if the laminated pane is a vehicle window, typically a LIN bus or CAN bus window). The switch, button, rotary or sliding controller can be integrated into the vehicle dashboard, for example, if the laminated pane is a vehicle window pane. However, touch sensors, such as capacitive or resistive sensors, can also be integrated directly into the laminated pane. Alternatively, the functional element can be controlled by non-contact methods, for example, by gesture recognition or depending on the state of the pupil or eyelid, as determined by a camera and appropriate evaluation electronics. The control unit may include, for example, an electronic processor, a voltage converter, transistors, and other components.

[0039] The voltage applied to the planar electrode is preferably an AC voltage. In a preferred embodiment, the power source is a DC power source, which generates a DC voltage and supplies the DC voltage to the control unit. This situation occurs, for example, in a vehicle when the laminated glass pane is a vehicle pane and is connected to the on-board voltage. The control unit is preferably connected to the on-board electrical system, from which it obtains information about the voltage and, optionally, the switching state. In this case, the control unit includes at least one inverter to convert the DC voltage to an AC voltage. In a first embodiment, the control unit includes a single inverter. To separately control the electrode segments of the first planar electrode, the output pole of the inverter has multiple independent outputs, one of which is connected to each electrode segment. Thus, one output of the inverter corresponds to each switching area and is connected to the corresponding electrode segment of the first planar electrode. The individual outputs are typically realized by switches, which generate a voltage and then switch this voltage. These switches can be integrated directly into the inverter. Alternatively, the inverter itself may strictly have only a single output, and an external switch may be connected to this output to distribute the voltage to the switching regions. For purposes of the present invention, such an externally connected switch is also considered an inverter output. The second planar electrode is also connected to the inverter. In a second embodiment, the control unit includes multiple inverters, and each electrode segment of the first planar electrode is connected to its own inverter to separately control the electrode segments of the first planar electrode. Thus, one inverter output corresponds to each switching region and is connected to the corresponding electrode segment of the first planar electrode. The first embodiment has the advantage of being more cost-effective and space-saving. However, its disadvantage is that the switching regions can only be digitally switched between a 0% switching state and a finite switching state corresponding to the currently applied inverter output voltage.Although it is not possible to have each switching region have a different finite switching state (ie, they cannot be independently "dimmable"), this is possible without problems in the second embodiment.

[0040] The inverter can be operated so that a real AC voltage, including its negative component, is generated. This is possible not only when there is only a single inverter with independent outputs, but also when each switching area is assigned its own inverter. However, this solution is technically difficult in the case of DC power supplies, such as in vehicles, because negative potentials are not available. Alternatively, it is possible, and often preferable, to simulate the AC voltage directly. The control unit includes multiple inverters, with each electrode segment of the first planar electrode connected to a separate inverter and the second planar electrode connected to another inverter. Thus, each electrode segment of the first planar electrode and each second planar electrode are assigned their own inverter. The potentials of the inverters are modulated with a variable function, e.g., a sinusoidal function, where the potentials of the inverters of the electrode segments of the first planar electrode are in phase and the potentials of the inverters of the second planar electrode are out of phase, typically by 180°. The signal of the second planar electrode is then inverted compared to the signal of the first planar electrode. In this way, a time-varying, periodic potential difference is generated, with alternating relatively positive and negative components, which corresponds to an AC voltage.

[0041] Since the onboard voltage of a vehicle (e.g., 12-14 V) is typically not sufficient to fully switch the functional elements, the control unit preferably further comprises a DC-DC converter. This DC-DC converter is suitable for increasing the supplied supply voltage (primary voltage), i.e., converting this primary voltage to a higher secondary voltage (e.g., 65 V). The use of a DC-DC converter is not limited to vehicle situations and may be necessary or advantageous in other cases. The control unit is connected to a DC power source, which supplies the primary voltage. The DC-DC converter converts the primary voltage to a higher secondary voltage. The inverter converts the secondary voltage to an AC voltage (e.g., 48 V) suitable for the inverter. This AC voltage is then applied to the electrode segments of the first planar electrode on the one hand and to the second planar electrode on the other hand.

[0042] In an advantageous embodiment, the secondary voltage is between 5V and 70V and the AC voltage is between 5V and 50V.

[0043] In an advantageous development of the glazing unit according to the invention, the temperature of the laminated panes is measured.

[0044] In an advantageous development of the method according to the invention, the temperature T of the PDLC functional element is measured and steps A to D of the method according to the invention are only carried out if the temperature T is above 50°C, preferably above 60°C.

[0045] In an alternative or combined development of the method according to the invention, the temperature T of the PDLC functional element is measured and steps A to D are carried out only if, after the final application of the "on" switching state to the PDLC functional element, a temperature profile has been passed in which the temperature T at some point is above 40°C, preferably above 50°C, particularly preferably above 60°C.

[0046] Alternatively, or in combination with this, the applied voltage or the duration t of each "on" switching state can be adapted to the measured temperature.

[0047] It is assumed here that the laminated glass pane has a uniform temperature throughout, i.e., the temperature of the functional element coincides with the temperature of other areas of the laminated glass pane. This is typically at least approximately true. Thus, measuring the temperature of the laminated glass pane will at least approximately coincide with measuring the temperature of the functional element.

[0048] 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 measure the temperature of the laminated glass pane by means of the temperature sensor. The measurement signal of the temperature sensor is thus transmitted to the control unit and evaluated by the control unit, which then measures the temperature of the laminated glass pane by means 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 fixed to the laminated glass pane externally or assigned to the laminated glass pane. Preferably, the temperature sensor is attached to the interior surface of the inner pane. The temperature sensor can also be arranged in the control unit itself or in a fixing element that fixes the control unit to the laminated glass pane. In principle, it is also possible to use a temperature sensor that is not directly fixed to or integrated into the laminated glass pane, but that performs the temperature measurement at a distance, for example, an IR sensor that is arranged in the vicinity of the laminated glass pane and directed toward it.

[0049] In another advantageous embodiment, the control unit is adapted to measure the electrical impedance of the active layer and determine the temperature of the laminated pane, or more precisely, the functional element, from this electrical impedance. This is possible because the impedance (equivalent to a conventional ohmic resistance in the case of an AC voltage) is temperature-dependent. In particular, there is an injective relationship 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, which is correlated with temperature, decreases strictly monotonically. This embodiment has the advantage that a temperature sensor can be omitted. A temperature sensor would have to be incorporated as an additional component, complicating the design and increasing production costs.

[0050] Typically, the memory effect and temperature dependence of the switching behavior become very significant above a certain limiting temperature, while temperature-dependent changes below the limiting temperature are less pronounced. The limiting temperature for common functional elements is typically around 60°C. The temperature is higher, especially in strong sunlight. Therefore, in one development of the invention, the method can be implemented as follows: the temperature is measured and the method according to the invention is implemented only after a temperature higher than a predetermined lower limiting temperature (e.g., 50°C or 60°C) is reached.

[0051] The functional element according to the present invention is a PDLC (Polymer Dispersed Liquid Crystal) functional element, the active layer of which comprises liquid crystals embedded in a polymer matrix.

[0052] The functional element according to the invention is preferably a standard PDLC functional element, which has maximum transmittance and minimum opacity in the "on" switching state when a voltage is applied (clear, transmissive state), and minimum transmittance and maximum opacity in the "off" switching state when the voltage is turned off (opaque, non-transmissive (diffusive) state). This means that when no voltage is applied to the planar electrodes, the liquid crystals align randomly, resulting in strong scattering of light passing through the active layer. When a voltage is applied to the planar electrodes, the liquid crystals align in a common direction, increasing the transmittance of light through the active layer. However, other functional elements, the variations of whose optical properties are based on liquid crystals, for example PNLC (polymer network liquid crystal) functional elements, can also be used.

[0053] Alternatively, the functional element according to the invention is preferably a reverse PDLC functional element (also called a reverse-mode PDLC), which has maximum transmittance and minimum opacity in the "off" switching state when the voltage is switched off (clear, transmissive state), and minimum transmittance and maximum opacity in the "on" switching state when the voltage is applied (opaque, non-transmissive (diffuse) state). The teachings according to the invention apply here accordingly.

[0054] The above-mentioned controllable PDLC functional elements and their operation modes are known per se to those skilled in the art, and therefore a detailed description thereof can be omitted here.

[0055] In one advantageous embodiment, the PDLC functional element includes two carrier films in addition to the active layer and the planar electrodes, with the active layer and the planar electrodes preferably being arranged between these carrier films. The carrier films are preferably made of a thermoplastic material, such as polyethylene terephthalate (PET), polypropylene, polyvinyl chloride, fluorinated ethylene propylene, polyvinyl fluoride, or ethylene tetrafluoroethylene, with PET being particularly preferred. The thickness of the carrier films is preferably between 10 μm and 200 μm. Such functional elements can advantageously be purchased commercially, particularly as multilayer films cut to a predetermined size and shape, which are then laminated to form laminated panes. This lamination is preferably carried out via thermoplastic bonding layers corresponding to the outer and inner panes, respectively. Segmentation of the first planar electrode by laser radiation is possible even when the first planar electrode is incorporated into such a multilayer film. Thin, visually inconspicuous separation lines can be formed by laser processing, typically without damaging the underlying carrier film.

[0056] The side edges of the functional element can be sealed, for example, by bonding the carrier layers together or by (preferably polymer) tape. In this way, the active layer can be protected, in particular from the components of the intermediate layer (especially the plasticizer) diffusing into the active layer, which could lead to degradation of the functional element.

[0057] For electrical contact, the planar electrodes or electrode segments are preferably connected to so-called flat or foil conductors, which extend from the intermediate layer outward beyond the side edges of the laminated pane. The flat conductors have a strip-shaped metal layer as a conductive core, which, except for the contact surface, is typically surrounded by a polymer insulating sheath. Optionally, so-called busbars, such as conductive foils (e.g., copper foils) or strips of conductive printed material, can be arranged on the planar electrodes, with the flat or foil conductors connected to the busbars. The flat or foil conductors are connected to a control unit directly or via additional conductors.

[0058] In an advantageous embodiment, the control unit is fixed to the interior surface of the inner pane opposite the intermediate layer. The control unit can, for example, be attached directly to the surface of the inner pane. In an advantageous embodiment, the control unit is inserted into a fixing element, which is fixed to the interior surface of the inner pane, preferably by means of an adhesive layer. Such fixing elements are also known in the vehicle industry as brackets 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, no long cables are required between the control unit and the functional elements.

[0059] Alternatively, however, if the laminated pane is a vehicle window pane, the control unit may not be attached to the laminated pane but may be integrated into the vehicle's electrical system or secured to the vehicle body, for example. The control unit is preferably located invisibly within the vehicle interior, for example in the dashboard or behind paneling.

[0060] The laminated pane can be provided with an opaque cover print, particularly in the peripheral region, as is commonly done in the vehicle field, particularly for windshields, rear windows, and roof panes. The cover print is typically made from an 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 provided on at least one of the pane surfaces, preferably on the interior surface of the outer pane and / or inner pane. The cover print preferably surrounds the central see-through area in a frame-like manner and serves, in particular, to protect the adhesive connecting the laminated pane to the vehicle body from UV rays. If a control unit is attached to the interior surface of the inner pane, the control unit is preferably attached to the opaque region of the cover print.

[0061] A thermoplastic interlayer serves to connect two panes, as is common in laminated panes. Typically, a thermoplastic film is used, from which the interlayer is formed. In a preferred embodiment, the interlayer is formed from at least a first thermoplastic layer and a second thermoplastic layer, with a functional element disposed between them. The functional element is connected to the outer pane through a region of the first thermoplastic layer and to the inner pane through a region of the second thermoplastic layer. The thermoplastic layers preferably protrude 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, they can fuse together during lamination, fusion occurring so that the original layers are no longer recognizable and a uniform interlayer is present.

[0062] The thermoplastic layer can be formed, for example, by a single thermoplastic film, or it can be formed from sections of different thermoplastic films joined at their side edges.

[0063] In a preferred embodiment, the functional element, or more precisely, its side edges, are surrounded by a third thermoplastic layer. The third thermoplastic layer is frame-shaped with a recess into which the functional element is inserted. The third thermoplastic layer can be formed by a thermoplastic film with the recesses cut into it. Alternatively, the third thermoplastic layer can be composed of multiple film sections surrounding the functional element. In this case, the interlayer is formed by a total of at least three thermoplastic layers arranged flat on top of each other, each having a recess in which the functional element is placed. During manufacturing, the third thermoplastic layer is arranged between the first and second thermoplastic layers, with the side edges of all thermoplastic layers preferably coinciding. The third thermoplastic layer preferably has approximately the same thickness as the functional element. This compensates for local thickness differences resulting from the localized confinement of the functional element, thereby avoiding glass breakage during lamination and improving the visual appearance.

[0064] The layers of the intermediate layer are preferably made of the same material, although in principle they can be made of 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 layers or films contain primarily these materials (more than 50% by weight), and may optionally contain additional 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 a standard thickness of 0.38 mm or 0.76 mm can be used.

[0065] The outer and inner panes are preferably made of glass, as is customary for window panes, and particularly preferably soda-lime glass. 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, tinted, or colored. Depending on the application, the degree of tinting or coloring can be limited; for example, a certain light transmittance must be guaranteed, such as a light transmittance of at least 70% in the main viewing area A in accordance with Regulation 43 of the United Nations Economic Commission for Europe (UN / ECE) (ECE-R43 "Uniform Provisions for the Approval of Safety Glazing Materials and Their Installation in Vehicles").

[0066] 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, a scratch-resistant coating, a photocatalytic coating, a UV-absorbing or reflective coating, or an IR-absorbing or reflective coating, such as a solar-blocking coating or a Low-E coating.

[0067] The thickness of the outer and inner panes can vary over a wide range 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.

[0068] 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 a window pane of a motorized vehicle. The glazing unit can be used, for example, as a windshield, roof pane, rear wall pane or side pane.

[0069] In a particularly preferred embodiment, the glazing unit or laminated pane is a vehicle windshield. The functional element is preferably used as an electrically controllable sunscreen located in the upper region of the windshield, while the majority of the windshield is free of the functional element. The switching areas are preferably arranged substantially parallel to the upper edge of the windshield and at increasing distances from the upper edge. The independently switchable switching areas allow a user to determine, depending on the position of the sun, which areas of the area adjacent to the upper edge should be in a state where they are shading or where high light scattering is provided, thereby avoiding dazzling from sunlight.

[0070] In yet another preferred embodiment, the glazing unit or laminated pane is a roof pane of a vehicle. In this case, the functional element is preferably disposed over 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 region where an opaque cover print is provided on at least one surface of the pane. The functional element extends over the entire see-through region, and its side edges are hidden from the viewer because they are disposed within the opaque cover print region. The switching regions are preferably disposed substantially parallel to the leading edge of the roof pane and at increasing distances from the leading edge. The independently switchable switching regions allow a user to determine which regions of the roof pane should be transparent and which regions should be shading or providing high light scattering depending on the position of the sun, thereby avoiding excessive heating inside the vehicle interior. It is also possible for each vehicle occupant, e.g., the driver, front seat passenger, left rear seat passenger and right rear seat passenger, to be assigned a switching area located above each occupant.

[0071] The invention will now be explained in more detail with reference to the drawings and exemplary embodiments, which are schematic and not to scale, and which are not intended to limit the invention in any way. [Brief explanation of the drawings]

[0072] [Figure 1] FIG. 1 is a plan view of one embodiment of a glazing unit according to the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the glazing unit of FIG. 1. [Figure 3] FIG. 3 is an enlarged view of the Z region in FIG. 2. [Figure 4] FIG. 2 is an equivalent circuit diagram of a PDLC functional element of the glazing unit of FIG. 1. [Figure 5] 1 a) and 1b) are schematic illustrations of the switching behavior of a PDLC functional element in a method according to the prior art. [Figure 6] 3a) to 3c) are schematic illustrations of the switching behavior of a PDLC functional element in a method according to the invention. [Figure 7] 1A to 1C are schematic diagrams of a typical application example. [Figure 8] a) and b) are schematic diagrams of another typical application. DETAILED DESCRIPTION OF THE INVENTION

[0073] 1, 2, 3, and 4 each show details of a glazing unit 100 including a PDLC functional element 4 with electrically controllable optical properties according to the present invention. Glazing unit 100 includes a laminated pane, which may be used, for example, as a roof pane for a passenger vehicle, and whose optical properties, such as light transmittance or light scattering, can be electrically controlled in specific regions. The laminated pane includes an outer pane 1 and an inner pane 2 connected to each other by an interlayer 3. The outer pane 1 and the inner pane 2 are made of, for example, soda-lime glass, which may be optionally tinted. The outer pane 1 has a thickness of, for example, 2.1 mm, and the inner pane 2 has a thickness of 1.6 mm.

[0074] The intermediate layer 3 includes, for example, three thermoplastic layers 3a, 3b, and 3c, each formed of a 0.38 mm thick PVB thermoplastic film. 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 the outer and inner panes, has a notch into which the PDLC functional element 4 is inserted so as to fit precisely, i.e., be substantially flush on all sides. Thus, the third thermoplastic layer 3c forms a kind of mount or frame for the approximately 0.4 mm thick functional element 4. The functional element 4 is thus encapsulated and protected by the thermoplastic material. The PDLC functional element 4 is, for example, a PDLC multilayer film that can be switched from a clear, transmissive state to an opaque, non-transmissive (diffusive) state.

[0075] Here, the PDLC multilayer film is, for example, a standard PDLC multilayer film that has maximum transmittance and minimum opacity (clear, transmissive state) in the "on" switching state when a voltage is applied, and minimum transmittance and maximum opacity (opaque, non-transmissive (diffuse) state) in the "off" switching state when the voltage is switched off.

[0076] The PDLC functional element 4 is a multilayer film consisting of an active layer 5 sandwiched between two planar electrodes 8, 9 and two carrier films 6, 7. The active layer 5 contains a polymer matrix in which liquid crystals are dispersed. The liquid crystals align in response to a 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. On the active layer 5 side, the carrier films 6, 7 are provided with an approximately 100 nm thick ITO coating, which forms the planar electrodes 8, 9. The planar electrodes 8, 9 are connected to an electrical cable 14 via a busbar (not shown) (formed, for example, from a strip of copper foil), which provides an electrical connection to the control unit 10.

[0077] The control unit 10 is attached, for example, to the interior surface of the inner pane 2, opposite the intermediate layer 3. For this purpose, for example, a fixing element (not shown) is attached to the inner pane 2 by a gluing process, into which the control unit 10 is inserted. However, it is not necessary to attach the control unit 10 directly to the laminated pane. The control unit 10 could also be attached, for example, to the dashboard or the body of the vehicle, or it could be integrated into the on-board electrical system of the vehicle.

[0078] The laminated pane has a peripheral edge region provided with an opaque cover print 13. This cover print 13 is typically made of black enamel. This black enamel is imprinted by a screen printing method using a printing ink containing black pigment and glass frit and then baked onto the pane surface. The cover print 13 is provided, for example, on the interior surface of the outer pane 1 and also on the interior surface of the inner pane 2. The side edges of the functional element 4 are covered by this cover print 13. The control unit 10 is located within this opaque edge region, i.e., it is glued to the cover print 13 of the inner pane 2. At this location, the control unit 10 does not obstruct the view through the laminated pane and is visually unobtrusive. Additionally, because the control unit 10 is located a short distance from the side edges of the laminated pane, only short cables 14 are advantageously required for the electrical connection of the functional element 4.

[0079] The control unit 10 is in turn connected to the on-board electrical system of the vehicle, which for the sake of simplicity is not shown in Figures 1 and 2. The control unit 10 is suitable for applying a voltage to the planar electrodes 8, 9 of the PDLC functional element 4 in response to a switching signal specified by the driver, for example by pressing a button, which voltage is required for the desired optical state of the PDLC functional element 4 (switched "on" / "off" state).

[0080] The laminated pane may, for example, have four independent switching areas S1, S2, S3, S4 in which the switching states of the PDLC functional elements 4 can be set independently of one another by the control unit 10. The switching areas S1, S2, S3, S4 are arranged front to back in a direction from the leading edge to the trailing edge of the roof pane, where the terms "leading edge" and "trailing edge" refer to the direction of travel of the vehicle. The switching areas S1, S2, S3, S4 allow the vehicle operator to select (e.g., depending on the position of the sun) only one area of ​​the laminated pane to be diffusive, rather than the entire laminated pane, while the other areas remain transparent.

[0081] To form the switching regions S1, S2, S3, and S4, the first planar electrode 8 is divided by three separating 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 separating lines 8' are typically introduced into the first planar electrode 8 by laser machining and further divide the first planar electrode 8 into four physically separated electrode segments 8.1, 8.2, 8.3, and 8.4. Each electrode segment 8.1, 8.2, 8.3, and 8.4 is independently connected to a control unit 10. The control unit is adapted to independently apply voltages between 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 section of the active layer 5 present therebetween is subjected to the voltage required to achieve the desired switching state.

[0082] As shown in the equivalent circuit diagram of FIG. 4, the control unit 10 is connected to a power source 15 via the vehicle's onboard electrical system. The power source 15 supplies a DC voltage, typically in the range of 12 V to 14 V (the vehicle's onboard voltage), in the vehicle area. The control unit 10 includes a DC-DC converter 11, which converts the onboard voltage (primary voltage) to a higher DC voltage, e.g., 65 V (secondary voltage). The secondary voltage must be high enough to ensure a 100% switching state of the PDLC functional element 4. Furthermore, the control unit 10 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 pole, the inverter 12 has several independent outputs, each connected to one of the electrode segments 8.1, 8.2, 8.3, and 8.4 in each case by one of the independent outputs, so that the switching states of the corresponding switching areas S1, S2, S3, and S4 can be set independently of the others.

[0083] In the case of a 0% ("off") switching state, the electrode segments 8.1, 8.2, 8.3, 8.4 and the second planar electrode 9 always have the same potential and no voltage is applied. When a switching area S1, S2, S3, S4 is in a switching state greater than 0% ("on"), a voltage is applied between the electrode segment 8.1, 8.2, 8.3, 8.4 in question and the second planar electrode 9. This voltage causes a current to flow through that section of the active layer 5.

[0084] 5a and 5b show schematic diagrams of the switching behavior of a PDLC functional element 4 in a method according to the prior art. In this prior art comparative example, the glazing unit 100 has nine adjacent, independently switchable switching areas (S1 to S9), which are connected (for example according to the principle according to FIGS. 1 to 4) to a control unit 10, which is not shown in the figure.

[0085] 5a) shows alternating switching states, i.e., adjacent switching areas (electrode segments) have different switching states. For example, switching areas S1, S3, S5, S7, and S9 have an "off" switching state, which corresponds, for example, to maximum diffuseness (opacity or scattering) in the view through the PDLC functional element 4 in each switching area S1, S3, S5, S7, and S9. Switching areas S2, S4, S6, and S8, which are immediately adjacent and separated from each other by only a single separating line 8' (not shown in detail in this figure) between electrode segments 8.1 to 8.9, have an "on" switching state, which corresponds, for example, to minimum diffuse transmittance (i.e., maximum clarity).

[0086] FIG. 5b): If all switching regions S1 through S9 are now directly switched to the "off" switching state by changing the "on" switching state of switching regions S2, S4, S6, and S8, it should be noted that switching regions S2, S4, S6, and S8, whose switching state has been changed from "on" to "off," are less diffusive than switching regions S1, S3, S5, S7, and S9, which have been in the "off" switching state for some time and therefore may have different switching and temperature histories. This effect can be referred to as the memory effect mentioned above, and its magnitude increases with increasing temperature of the PDLC functional element 4. The resulting difference is aesthetically unattractive and may cause dazzlement to the driver or other occupants, for example in vehicle glazing.

[0087] In other words, the teachings of the present invention can be explained as follows: if a switching region of a PDLC functional element 4 is heated, for example, in an "off" switching state from room temperature to a temperature of, for example, 60°C, and then cooled again, the transparency of this "new" "off" switching state will subsequently differ from the "old" "off" switching state before undergoing this temperature profile. If the switching region of the PDLC functional element 4 is subsequently switched on ("on") and then switched off again ("off"), the initial "off" switching state, which corresponds to the "new" memory state, will be restored. Therefore, it is always desirable to ensure that adjacent switching regions are in the "new" memory state ("off" switching state) as soon as they are switched on and off again, because these adjacent switching regions will necessarily be in the aforementioned "new" memory state after being switched off.

[0088] 6a) and 6b) show schematic diagrams of the switching behavior of a PDLC functional element 4 when the method according to the invention is applied. In terms of its basic structure, the present example glazing unit 100 according to the invention corresponds to the comparative prior art glazing unit of FIG. 5, and therefore reference is made to the description of FIG. 5.

[0089] 6a) shows, like FIG. 5a), alternating switching states, i.e., adjacent switching regions have different switching states. For example, switching regions S1, S3, S5, S7, and S9 have an "off" switching state, which corresponds, for example, to maximum diffuseness (opacity or scattering) in the view through the PDLC functional element 4 in each switching region S1, S3, S5, S7, and S9. Directly adjacent switching regions S2, S4, S6, and S8 are separated from each other only by a single separation line 8' (not shown in detail in this figure) between electrode segments 8.1-8.9. These switching regions S2, S4, S6, and S8 have an "on" switching state, which corresponds, for example, to minimum diffuse transmittance (i.e., maximum clarity).

[0090] In contrast to the comparative examples according to the prior art in Figures 5a) and 5b), when changing the switching state of the individual switching areas, all switching areas S1 to S9 are first set to an "on" switching state for a period t of, for example, 0.5 s (see Figure 6b). Then, for example, all switching areas S1 to S9 are set to an "off" switching state by application of appropriate control voltages via the control unit 10.

[0091] As can be seen from Figure 6c), all switching regions S1 to S9 have the same optical properties, in particular the same diffusivity, regardless of whether these regions were originally in the "on" switching state (like switching regions S2, S4, S6, S8) or were already in the "off" switching state (like switching regions S1, S3, S5, S7, S9).

[0092] This provides a uniform field of view with little or no glare to the driver or other passengers. Regardless of the temperature T of the PDLC functional element 4, the memory effect shown in Figures 5a and 5b can be effectively avoided.

[0093] As already mentioned, the memory effect mentioned above always occurs to some extent, but particularly at temperatures above, for example, 50°C.

[0094] Although not limiting the present invention, this effect is particularly evident in the following initial configuration: Depending on the temperature changes of the glazing unit 100 in different application scenarios, the optical properties in the switched off state may change during operation and between two uses (morning / evening, next day). Figures 7a-c) show the scenario during operation of the vehicle. Figures 8a-b) show the scenario between two uses.

[0095] Figures 7a-7c show a schematic representation of the initial configuration of a vehicle parked in a garage: In Figure 7a, the vehicle is parked in the (relatively cool) garage and the glazing unit 100 with the PDLC functional element 4 is in the "off" switching state, i.e. not energized and therefore in a diffusing state.

[0096] Figure 7b) shows a glazing unit 100 with alternating "on" / "off" switching areas, where the glazing unit 100 heats up to above 60°C under the action of sunlight and with little airflow in city traffic, for example, over a period of about two hours.

[0097] Figure 7c) shows a glazing unit under the influence of temperature, where the switching area, now switched "off" for a long period of time, exhibits a higher diffuse transmittance than after a short switch on and at a lower temperature than in the state of Figure 7b). Figure 7c) corresponds, for example, to the initial state of Figure 5a) for a comparative example according to the prior art or Figure 6a) for an embodiment according to the invention.

[0098] By applying the method according to the invention, uniform optical properties are obtained over the entire surface of the switching region.

[0099] Figures 8a) and 8b) show another initial configuration schematically using the example of a vehicle parked in sunlight. In Figure 8a), the glazing unit 100 is relatively cool and in the "off" switched state, i.e., not energized and therefore in a diffusing state.

[0100] Figure 8b) shows the glazing unit 100 after about two hours of parking and after the sun has heated it up to, for example, over 60°C. Figure 8b) shows the glazing unit after the temperature change. The switching area, which has now been switched "off" for a long time, now exhibits a higher diffuse transmittance than in Figure 8a) before the temperature effect.

[0101] If an alternating switching pattern such as Figure 5a) or Figure 6a) is now applied to the glazing unit 100 and this alternating switching pattern is again immediately switched completely "off" (without an intermediate "on" switching state) according to the prior art, a pattern according to Figure 5b) results. The switching areas S1, S3, S5, S7, S9 that were not switched "on" retain a stronger diffusivity than the switching areas S2, S4, S6, S8 that were switched "on" and then switched "off" again, because the memory state is now restored in the switching areas S2, S4, S6, S8.

[0102] By switching all switching regions "on" in accordance with the present invention (as shown in Figure 6b), the memory state of the PDLC functional element is restored, so that when all switching regions are subsequently switched "off", uniform light diffusivity occurs across the entire surface of the switching regions (see Figure 6c). [Explanation of symbols]

[0103] 1 outer pane 2 inner panes 3 Thermoplastic Interlayer 3a First layer of intermediate layer 3 3b Second layer of intermediate layer 3 3c Third layer of middle layer 3 4. PDLC functional elements with electrically controllable optical properties 5. Active layer of functional element 4 6. First carrier film of functional element 4 7 Second carrier film of functional element 4 8 First planar electrode of functional element 4 8.1, 8.2, 8.3, 8.4 Electrode segments of the first planar electrode 8 8' Separation line between two electrode segments 8.1, 8.2, 8.3, 8.4 9 Second planar electrode of functional element 4 10. Control Unit 11 DC-DC converter 12 inverters 13 Cover Print 14 Electrical Cables 15 Power supply / DC power supply 100 glazing units S1, S2, S3, S4, S5, S6, S7, S8, S9, Sn, Sn+1 switching regions n natural number t period T temperature X-X' cutting line Z expansion area On / off switching status

Claims

1. A method for controlling a PDLC functional element (4) having at least two adjacent, independently switchable switching areas (Sn, Sn+1, where n=1 to 8), comprising applying a switching state (on, off) to said switching areas (Sn, Sn+1) by a control unit (10), A) applying different switching states (ON, OFF) to at least two adjacent switching regions (Sn, Sn+1), B) sending a signal to the control unit (10) by user or automatic control to change the switching state (on, off) of each of the switching areas (Sn, Sn+1); C) First, set all switching regions (S1, S2, S3, S4, S5, S6, S7, S8, S9) to the "ON" switching state; D) then applying said modified switching states to said switching regions (S1, S2, S3, S4, S5, S6, S7, S8, S9).

2. 2. The method of claim 1, wherein in step C, the "on" switching state is applied simultaneously in all switching regions (S1, S2, S3, S4, S5, S6, S7, S8, S9).

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

4. 4. The method according to claim 1, wherein in step C, the "on" switching state is maintained in the switching regions (S1, S2, S3, S4, S5, S6, S7, S8, S9) for a period t of at least 1 / 60 s, preferably at least 0.5 s, in particular 0.5 s to 10 s.

5. 5. The method according to claim 1, wherein the method is carried out again in step D when different switching states (ON, OFF) are applied to at least two adjacent switching areas (Sn, Sn+1).

6. 6. The method according to claim 1, wherein the temperature T of the PDLC functional element (4) is measured and steps A to D are carried out only if the temperature T is above 40°C, preferably above 50°C, particularly preferably above 60°C; and / or the temperature T of the PDLC functional element (4) is measured and steps A to D are carried out only if, after the final application of the "on" switching state to the PDLC functional element (4), the PDLC functional element (4) has undergone a temperature profile in which the temperature T at a certain point in time is above 40°C, preferably above 50°C, particularly preferably above 60°C.

7. A glazing unit (100) comprising a PDLC functional element (4), comprising: ·below: an outer pane (1) and an inner pane (2) connected to each other by at least one thermoplastic intermediate layer (3); a PDLC functional element (4) having at least two adjacent, independently switchable switching areas (Sn, Sn+1, where n=1 to 8), said PDLC functional element (4) being arranged between said outer pane (1) and said inner pane (2), wherein: a PDLC functional element (4), which has at least two adjacent, independently switchable switching areas (Sn, Sn+1, where n=1 to 8); a laminated pane (101) comprising: and A control unit (10) for electrically controlling the optical properties of the switching regions (S1, S2, S3, S4, S5, S6, S7, S8, S9) of the PDLC functional element (4), the control unit (10) being arranged to implement the method according to any one of claims 1 to 6. A glazing unit (100) comprising:

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

9. 9. The glazing unit (100) according to claim 8, wherein each electrode segment (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and the second planar electrode (9) are electrically connected to the control unit (10), thereby enabling voltages to be applied independently between each electrode segment (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8) and the second planar electrode (9), thereby controlling the optical properties of the section of the active layer (5) located therebetween.

10. 9. A glazing unit (100) according to claim 8, wherein the second planar electrode (9) has no separating lines (8') or a smaller number of separating lines (8') than the first planar electrode (8), and thus a smaller number of electrode segments than the first planar electrode (8), so that at least one electrode segment of the second planar electrode (9) is assigned to a plurality of electrode segments (8.1, 8.2, 8.3, 8.4) of the first planar electrode (8).

11. 11. A glazing unit according to any one of claims 7 to 10, wherein the laminated pane is provided with a temperature sensor, the temperature sensor being connected to the control unit (10) so that the control unit (10) can measure the temperature T of the laminated pane by means of the temperature sensor, or the control unit (10) is suitable for measuring the impedance of the active layer (5) and determining the temperature T of the laminated pane from the impedance.

12. Glazing unit according to any one of claims 7 to 11, 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, equipped with a glazing unit (100) according to any one of claims 7 to 12.

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

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