DE102022134758B4 - Mounting kit with control circuit for a switchable privacy film on a window and its use - Google Patents

Abstract

Mounting kit (1) for attaching a switchable privacy protection film (3) to a window, the frame (16) of which has a plurality of corners (16a) and straight sides (16b) extending therebetween, comprising: a privacy protection film (3) that can be cut to the respective window size and that can be switched between a transparent state and a privacy protection state at least in a partial area of its surface and for this purpose comprises an electrically switchable layer between two electrically conductive layers, each of which is connected to an electrode (3a, 3b) for applying electrical voltage therebetween; one or more clamping strips (4) that can be cut to the respective lengths of the frame sides (16b), which are self-adhesive on the back and designed on the front for replaceable clamping of the privacy protection film (3); one corner clamping angle (5) for each frame corner (16a), which is self-adhesive on the back and designed on the front for replaceable clamping of the privacy protection film (3), and whose Angle legs (7a, 7b) on both frame sides (16b) can be clearly positioned in the respective corner by mechanical stop or by alignment, wherein each corner clamping angle (5) has several straight edges (19, 21), marking lines (22) and/or projections for a clear positioning of the terminal strips (4) to be applied thereto and the privacy film (3) to be clamped therein and at least two corner clamping angles (5) are designed for contacting the electrodes (3a, 3b); andan electronic control element (6) which is designed to be connected to the at least two corner clamping brackets (5) and for the user to switch the privacy protection film (3) between its transparent and privacy protection state and for this purpose has a control circuit (30), wherein the control circuit (30) has two independently controllable half-bridges (31a, 31b), which can be connected to one of the two electrodes (3a, 3b) of the privacy protection film (3) and are each designed as a step-down converter; so that by controlling both step-down converters the privacy protection film (3) can be switched between its transparent and privacy protection state, wherein each electrode (3a, 3b) can be controlled independently of the other electrode (3b, 3a) via the associated step-down converter.

Description

Field of the invention

The invention relates to an assembly kit for attaching a switchable privacy film to a window with a control circuit and a use of the assembly kit. By means of a control, the privacy film can be switched between a transparent state and a privacy protection state at least in a partial area of its surface and for this purpose comprises an electrically switchable layer between two electrically conductive layers, each of which is connected to an electrode for applying electrical voltage between them.

It is known to equip windows and other transparent panes with switchable films, for example based on liquid crystals. By switching the film between an opaque and a transparent state, temporary privacy can be created at the push of a button.

State of the art

Control circuits known from the prior art for electrically controlling switchable films of this type are typically designed not only for switching between an opaque and a transparent state, but also for gradually switching the film between several intermediate transparency or dimming levels in order to enable the user, depending on the situation, to set a different degree of opacity or, if necessary, different color levels in liquid crystal films additionally mixed with dyes. For this purpose, various control circuits and methods are proposed in the prior art that enable a step-by-step adjustment of the amplitude of an alternating voltage to be applied to the switchable film and thus a step-by-step adjustment of the degree of alignment of the liquid crystals in the film.

For example, EP 2 622 407 B1 proposes a transparency adjustment system comprising: a transparent physical element (LC, liquid crystal) whose electrical behavior is that of a capacitive load; and a power dimmer device. The latter serves to apply AC voltage to the transparent physical element to produce a set of transparency states including a plurality of transparency states other than complete transparency. To this end, the power dimmer device comprises a single power switch that supplies power to the transparent physical element and a single control circuit having a comparator that serves to receive and compare an incoming AC voltage level and a user-selected reference voltage. When the incoming AC voltage level reaches the user-selected reference voltage, an output is generated that triggers the clipping of the sinusoidal AC voltage applied to the transparent physical element so that the control circuit controls the turning on and off of the power switch. The direct current voltage reaching the transparent physical element from the individual circuit breaker shall necessarily not exceed 1% of the alternating current voltage supplied to the transparent physical element.

Furthermore, for example, EP 3 920 174 A1 for a similar purpose, a control circuit for a switchable glass, the control circuit comprising a controller for receiving a control command and for outputting a corresponding voltage control signal, and a voltage adjustment circuit. The voltage signal with an adjustable alternating voltage amplitude output by the voltage adjustment circuit adjusts the transparency of the switchable glass, so that the degree of deflection of the liquid crystal molecules in the switchable glass is controlled by the said amplitude adjustment.

Apart from such amplitude adjustment, the control circuits and control elements described and available in the prior art are typically also designed for comparatively large-area switchable films and require correspondingly large transformers and electrical power for their operation.

The state of the art also proposes solutions for retrofitting an existing window with an electrically switchable layer. Due to the comparatively complex electrical functionality, correct installation of the switchable layer or its dimensioning and electrical contact usually requires professional implementation.

For example, WO 02 / 029 471 A1 a method of retrofitting a window by attaching a switchable or non-switchable window enhancement. The switchable enhancement may be, among others, a film with dispersed particles, an electrochromic film or a liquid crystal film. The film is attached to the window in such a way that it at least partially overlaps the window pane, leaving a gap between the window pane and the enhancement. For this purpose, fastening means in the form of Strips or squares or other shaped elements glued to both the window and the film are used, each of which extends over a section of two opposite sides of the window, for example. Fasteners glued to the window on the one hand and to the film on the other can be magnetic strips or clip or snap-in elements. Alternatively, screw and rivet connections are also mentioned for attaching the film to the window. Contacting the switchable film, i.e. its electrical connection to a control element and a voltage source for optionally applying suitable alternating voltage, is expressly left to a specialist in this field.

On the other hand, EP 3 534 357 A1 A clamping band is known which is used to fix an information carrier, such as a paper medium, such as a poster, a piece of paper, a note, or another display medium, which has a weight and dimensions comparable to a piece of paper or cardboard, to a support surface such as a wall or a pane of glass. The clamping band can be wound up into a roll and has a flexible strip-shaped carrier which specifies the dimensions of the clamping band, such as the width. The carrier, e.g. a film strip, has a first flat side and an opposite second flat side. The clamping band also comprises at least one flat first magnetic element and at least one flat second magnetic element on the first flat side of the carrier, which are designed in particular as magnetic strips and are arranged on the carrier, leaving a strip-shaped free space strip extending in the longitudinal direction of the carrier. They therefore do not touch each other. The free space strip allows the carrier and thus the clamping band or a clamping band section to be folded along its longitudinal axis and thus form a film hinge between the first magnetic element and the second magnetic element. This film hinge allows the carrier or the clamping band section to be opened and folded back together in the longitudinal direction as often as desired. The clamping band can have an adhesive element for attachment to the carrier surface, in particular in a way that can be removed without leaving any residue. This adhesive element is arranged on a second flat side of the carrier and comprises, for example, an adhesive element or a layer.

Furthermore, the applicant’s German patent application EN 10 2022 129 355 A1 A mounting kit and an associated installation procedure have been presented which, among other things, enable even a user with no practical experience to retrofit an existing window with a switchable privacy film in an uncomplicated and error-free manner.

From the WO 2021 / 254 761 A1 A method for electrically controlling a functional element with electrically controllable optical properties enclosed in a glazing unit is known, which comprises controlling the optical properties by a control unit connected to two transparent flat electrodes of the functional element and applying a voltage by the control unit between the flat electrodes, the polarity of the voltage being periodically changed.

The EN 10 2018 214 497 B4 discloses a converter circuit for generating an alternating voltage from a direct voltage, characterized by a first input terminal and a second input terminal for receiving the direct voltage, a boost converter circuit connecting the first and the second input terminal, and a buck converter circuit connected downstream of the boost converter circuit, which provides the alternating voltage between a first and a second output terminal.

The EN 10 2018 208 323 A1 relates to a window device and a window system with such a window device. The window device can be arranged, for example, on existing windows as an additional unit. The window device has a frame, a transparent pane device arranged on the frame, a liquid crystal film arranged on the transparent pane device, and a fastening device arranged on the frame and designed for detachable fastening to a window frame of another transparent pane device.

Task

The object of the invention is to provide an alternative or improved control circuit and a corresponding control method and control element for controlling a switchable privacy film of the type mentioned above, which can be optimized in particular for use in or on windows in the private and commercial sector. This can in particular be an improvement with regard to the complexity and/or the size of the control circuit and/or the control method and the control element and/or with regard to the electrical power required. In particular, it can also be an object to provide a control circuit that is suitable and/or optimized for use in the above-mentioned novel assembly kit.

Solution

This object is achieved by the invention with the features of the independent claim. Advantageous developments of the invention are characterized in the subclaims and the subordinate claims that refer back to the independent claim. The wording of all claims is hereby made part of the content of this description by reference. The invention also includes all reasonable and in particular all mentioned combinations of independent and/or dependent claims. All features and technical effects that are described below with reference to the control circuit also apply mutatis mutandis to the control method, control element, privacy protection system and to the assembly kit according to the invention and its use, and vice versa.

The present invention relates in particular to an assembly kit with a control circuit for controlling a switchable privacy film that is designed for use in or on a window. The privacy film is designed for use as part of a window pane or for attachment to an existing window and is dimensioned to partially or completely cover the pane surface. The privacy film can be switched between a transparent state and a privacy protection state at least in a portion of its surface and for this purpose comprises an electrically switchable layer between two electrically conductive layers, each of which is connected to an electrode for applying electrical voltage between them.

The window can in particular have a frame with several corners and straight sides extending between them. It can be a rectangular window, for example, but the present invention is not limited to this. Rather, the window frame can, for example, be a regular or irregular polygon with a number of corners and sides other than four, such as a triangle, pentagon, hexagon or a rhombus with non-rectangular corners.

The electrically switchable layer can in particular be designed as a liquid crystal layer and its above-mentioned layer structure can be designed such that when electrical voltage is applied to the two electrodes via the electronic control element described below with the control circuit presented here, the liquid crystals align largely parallel to one another and the film is therefore in its transparent state. If, on the other hand, no electrical voltage is applied to the electrodes, the liquid crystals are largely random and therefore distributed or oriented differently among one another and scatter the light that passes through the privacy film so that it is in its privacy state. It can, for example, appear milky or opaque and therefore non-transparent. This liquid crystal technology is also known in particular under the name PDLC film or device (polymer-dispersed liquid-crystal devices), in which liquid crystals of the switchable layer were dissolved or dispersed in a liquid polymer during its production and, after the polymer has subsequently hardened, are present in droplets of a different size depending on the curing conditions. Alternatively, other types of electrically switchable layers can be used that switch between a transparent and a privacy-protection state by applying electrical voltage, for example based on anisotropic or polarizable particles dispersed in a fluid or on electrochromic properties or on a polarization-rotating liquid crystal layer between two crossed polarizers and much more.

In particular, the privacy film in its transparent state can be essentially transparent (i.e. see-through) to visible light in a predetermined angle of incidence range around a surface normal of the film. In its privacy state, the privacy film can in particular be essentially opaque or matt to visible light, for example due to light scattering and/or light absorption in the electrically switchable layer or due to light absorption up to light blocking by crossed polarizers if the electrically switchable layer is designed, for example, as a layer that rotates polarization depending on the applied electrical voltage.

The control circuit presented here has two independently controllable half-bridges, each of which can be connected to one of the two electrodes of the privacy film (i.e., during operation, they are electrically connected to one of the two electrodes). Each of these half-bridges is designed as a step-down converter (also known as a step-down converter or buck converter). Both half-bridges/step-down converters can in particular be designed without common components and without electrical connections to one another, possibly apart from a connection to a common power supply source.

By controlling both down converters, the privacy film can be switched between its transparent and privacy protection state. As described below As described in more detail, the voltage at the respective electrode can be set between 0 V and a predetermined input DC voltage, whereby each of the two step-down converters can, for example, map a half-wave of a sinusoidal PWM control signal to set the transparency state of the film. A coil and a capacitor contained in the respective step-down converter smooth out the voltage that results from the purely exemplary sinusoidal PWM control signal.

In principle, each electrode can be controlled independently of the other electrode via the associated step-down converter. This makes it possible, among other things, to reproduce a desired alternating voltage curve, such as a sine curve, particularly well in order to achieve the most uniform transparency possible in the clear state of the switchable film.

One of the features of this control circuit is that it is quite small compared to the state of the art and basically does not require large transformers. The comparatively small size of the control circuit and the resulting control element (see below) and its low power consumption compared to the state of the art outlined at the beginning is also related to the limited size of the switchable foils to be controlled, which, in contrast to the state of the art, can be designed for small to normal-sized windows in private or business areas. This requires less power than conventional control circuits, which can also be used for switchable foils with an area corresponding to an entire office or house wall, for example.

In addition, the circuit presented here does not require any sub-circuits or extra components, which in the prior art are specifically provided for the dimming function, i.e. for setting several different transparency or dimming levels of the switchable film. With this control circuit, the desired dimming can also be set step by step if required by appropriately controlling both down converters, for example by appropriately designing the PWM control signal.

For example, with the present control circuit, an electrical power consumption of up to about 8 W, in particular up to about 5 W or even only up to about 2 W or up to about 1 W per square meter of the film surface can be achieved. This can also contribute, among other things, to compliance with specified requirements for a protective extra-low voltage of, for example, a maximum of 50 V AC, in particular a maximum of 25 V AC for damp rooms.

The two half-bridges, i.e. step-down converters, can be designed identically to one another. However, this is not absolutely necessary, i.e. they can in principle be designed differently from one another, since they can be controlled independently.

According to one embodiment, a first of the two step-down converters can be controlled to convert a predetermined first input direct voltage into a first output alternating voltage intended for a first electrode of the privacy film and for this purpose has a first electrically controllable switch and a second electrically controllable switch, which are connected in series between a source of the first input direct voltage and ground, as well as a first second-order low-pass filter with a first coil and a first capacitor, designed to smooth the first output alternating voltage.

Alternatively or additionally, the second step-down converter can also be controlled to convert a predetermined second input DC voltage into a second output AC voltage intended for the second electrode of the privacy film and for this purpose can have a third electrically controllable switch and a fourth electrically controllable switch, which are connected in series between a source of the second input DC voltage and ground, as well as a second second-order low-pass filter with a second coil and a second capacitor designed to smooth the second output AC voltage. The first and second input DC voltages can in particular be the same and connected to a common voltage source, for example in the form of a plug for a suitable power supply unit, which transforms an available supply network AC voltage into the required input DC voltage of both step-down converters and can in particular also be provided separately from the control circuit.

In a specific embodiment, the first or the second coil or both coils each have a predetermined inductance between approximately 50 µH and approximately 250 µH, preferably between approximately 100 µH and approximately 200 µH, particularly preferably between approximately 125 µH and approximately 175 µH, in particular approximately 150 µH. This can in particular contribute to the above-mentioned low power consumption and/or a particularly good smoothing result of the low-pass filter. These coils can be loaded with up to 600 mA of current, for example.

In a specific embodiment, the first or the second capacitor or both capacitors each have a predetermined capacitance between about 1 µF and about 20 µF, preferably between about 5 µF and about 15 µF, particularly preferably between about 7.5 µF and about 12.5 µF, in particular about 10 µF, for example at about 50 V AC. This can in particular contribute to the above-mentioned low power consumption and/or a particularly good smoothing result of the low-pass filter.

In particular, one or more of the four switches mentioned can each have a transistor, preferably a MOSFET. In particular, the transistors used in the respective half bridges are usually each bridged by a diode.

• - einen Benutzereingaben-Wandler, der zum Umwandeln manueller Umschalt-Eingaben eines Benutzers für die schaltbare Folie in entsprechende elektrische Eingabe-Signale ausgebildet ist und beispielsweise einen oder mehrere Druck- oder Drehknöpfe, Hebel oder ein Touch-Screen umfassen kann;
• - einen Benutzereingaben-Empfänger, der zum Empfangen und Umwandeln drahtlos übermittelter Umschalt-Eingaben eines Benutzers für die schaltbare Folie in entsprechende elektrische Eingabe-Signale ausgebildet ist;
• - einen (Mikro-)Controller, der an seinem Eingang zum Erhalten elektrischer Eingabe-Signale ausgebildet ist, die auf manuellen und/oder drahtlos übermittelten Umschalt-Eingaben eines Benutzers basieren, und an seinem Ausgang zum Ausgeben eines entsprechenden digitalen Ansteuerungssignals, insbesondere in Form eines (beispielsweise sinusförmigen) PWM-Signals, für die beiden Halbbrücken ausgebildet ist. Es kann sich insbesondere um einen integrierten Mikrocontroller handeln;
• - eine Transistor-Treiberschaltung, die an ihrem Eingang zum Erhalten eines basierend auf benutzerseitigen Umschalt-Eingaben erzeugten Ansteuerungssignals für die beiden Halbbrücken ausgebildet ist und an ihrem Ausgang zum Ausgeben entsprechender Gate-Ansteuerungsspannungen oder -Stromstärken für in den beiden Halbbrücken als Schalter enthaltene Transistoren ausgebildet ist. Es kann sich insbesondere um eine integrierte Transistor-Treiberschaltung handeln, die sich beispielsweise in einem gemeinsamen Gehäuse mit den Transistoren befindet. Die Treiberschaltung stellt insbesondere sicher, dass die Gates der Transistoren in der nötigen Zeit (die sich beispielsweise aus der Gate-Kapazität und der PWM-Frequenz ergibt) geladen und entladen werden. Sie kann insbesondere ohne einen Verstärker auskommen, sodass diese Schaltung in den hierin beschriebenen gut funktionierenden Ausführungsbeispielen auch jeweils keinen Verstärker aufweist. Zudem kann vorzugsweise über eine ebenfalls integrierte Charge-Pump ein nötiger Pegel für einen der Transistoren, beispielsweise für den High-Side N-Kanal-Mosfet, erzeugt werden.

According to one embodiment, the control circuit further comprises one or more of the following components:

• - a user input converter which is designed to convert manual switching inputs of a user for the switchable film into corresponding electrical input signals and can comprise, for example, one or more push or rotary buttons, levers or a touch screen;
• - a user input receiver configured to receive and convert wirelessly transmitted switching inputs from a user for the switchable film into corresponding electrical input signals;
• - a (micro)controller which is designed at its input to receive electrical input signals based on manual and/or wirelessly transmitted switching inputs from a user, and at its output to output a corresponding digital control signal, in particular in the form of a (for example sinusoidal) PWM signal, for the two half-bridges. In particular, it can be an integrated microcontroller;
• - a transistor driver circuit which is designed at its input to receive a control signal for the two half-bridges generated based on user-side switching inputs and is designed at its output to output corresponding gate control voltages or currents for transistors contained as switches in the two half-bridges. In particular, it can be an integrated transistor driver circuit which is located, for example, in a common housing with the transistors. The driver circuit ensures in particular that the gates of the transistors are charged and discharged in the necessary time (which results, for example, from the gate capacitance and the PWM frequency). In particular, it can manage without an amplifier, so that this circuit does not have an amplifier in the well-functioning embodiments described here. In addition, a necessary level for one of the transistors, for example for the high-side N-channel MOSFET, can preferably be generated via a charge pump which is also integrated.

The present invention also relates to a method for controlling the above-mentioned switchable privacy film by using the control circuit presented herein.

In this control method, the two step-down converters are controlled synchronously depending on manual and/or wirelessly transmitted switching inputs of a user for the privacy film in such a way that each step-down converter, alternating in time with the other step-down converter, maps a half-wave of an alternating voltage of a predetermined alternating voltage frequency (which results in the above-mentioned first or second alternating voltage at the output of the respective step-down converter) and applies it to the associated electrode.

The first or second output alternating voltage to be applied to the respective electrode of the switchable film is digitally mapped, for example in the form of a sinusoidal pulse width modulation (PWM), via the switches contained in the associated down converter and smoothed by the first or second second order low-pass filter contained in the associated down converter. The frequency of the alternating voltage to be applied to the film can, purely by way of example, be in the range from about 40 Hz to about 60 Hz, in particular between about 45 Hz and 55 Hz, for example at about 50 Hz. The PWM sampling frequency can, for example, be in a range from about 30 kHz to about 85 kHz, in particular between about 45 kHz and about 70 kHz, in order to obtain a sufficiently smooth mapping of, for example, a sinusoidal alternating voltage for the application described here with a comparatively low power consumption, as mentioned above.

The present invention also relates to an electronic control element for the above-mentioned switchable privacy protection film. The control element is designed for electrical connection to the two electrodes of such a privacy protection film and for user-side Switching the privacy film between its transparent and privacy protection state and for this purpose has the control circuit presented here. In particular, the control element can be designed and set up to carry out the control method described here for the switchable film mentioned.

Furthermore, the present invention also relates to a switchable privacy protection system which comprises both the above-mentioned switchable film and the above-mentioned electronic control element for user-side switching of the privacy protection film between its transparent and privacy protection state.

The switchable film mentioned herein or its partial area which can be switched between a transparent state and a privacy protection state can in particular have an area of, in the following order, increasingly preferably between approximately 0.05 m ² and approximately 10 m ² , between approximately 0.1 m ² and approximately 7 m ² , between approximately 0.2 m ² and approximately 5 m ² , between approximately 0.3 m ² and approximately 4 m ² , between approximately 0.4 m ² and approximately 3 m ² , between approximately 0.5 m ² and approximately 2 m ² , between approximately 0.6 m ² and approximately 1.5 m ² or between approximately 0.7 m ² and approximately 1.0 m ² . Alternatively or simultaneously, a largest linear dimension or one or two linearly independent average or characteristic linear dimensions of the privacy film, in particular one or both side length(s) or diagonal(s) of a rectangular or other quadrangular film surface, can be, in the following order, increasingly preferably between about 0.3 m and about 4.0 m, between about 0.35 m and about 3.5 m, between about 0.4 m and about 3.0 m, between about 0.45 m and about 2.5 m, between about 0.5 m and about 2.0 m, between about 0.55 m and about 1.5 m or between about 0.6 m and about 1.0 m. The control circuit presented here can be optimized in particular for such a dimensioning of the switchable film. As mentioned above, these size ratios can sometimes also contribute to a comparatively low power consumption of the control circuit and the suitability of its electronic components mentioned here with correspondingly comparatively small sizes, etc.

In a specific embodiment, the two electrodes are at a predetermined distance from each other, measured along the film surface, in order to achieve, for example, the most uniform possible electrical field distribution between the two electrically conductive layers and thus in the switchable layer. The said distance can, for example, correspond to at least about a third or a half of the largest linear dimension or the length of the individual electrode in the film surface or at least about an entire largest linear dimension or length of the individual electrode in the film surface.

The present invention also relates in particular to an above-mentioned mounting kit for the subsequent attachment of the above-mentioned switchable privacy film to a window whose frame has several corners and straight sides extending between them. This can in particular be the mounting kit mentioned at the beginning, which is described in the EN 10 2022 129 355 A1 was presented. The assembly kit contains the above-mentioned privacy film itself as well as the electrical control element presented here, so that the control element together with the privacy film tailored to the respective window size form the above-mentioned privacy system.

The installation kit and the privacy film contained therein can be designed in particular to cover the entire surface of a window pane bordered by the window frame with the privacy film. In order to enable a user to attach the privacy film to windows of different sizes or shapes, the privacy film is designed in such a way that it can be cut to an individual window size by the user. For example, standard household or paper scissors can be used for this. Alternatively or additionally, a suitable cutting tool can also be included in the installation kit.

As already mentioned above, the privacy film can be switched between a transparent state and a privacy protection state at least in a partial area of its surface, in order to enable the user to create privacy at the touch of a button by attaching the film to a transparent window pane. For this purpose, the privacy film comprises an electrically switchable layer in the area mentioned, which is arranged between two electrically conductive layers, each of which is connected to an electrode for applying electrical voltage between them. The electrically conductive layers can be protected on the outside by electrically insulating and mechanically stabilizing cover layers, which are permanently connected to the privacy film as an integral part of a multi-layer structure. In addition, the privacy film can be protected on the outside, particularly in the area of the electrodes, against external damage such as scratches, etc. by removable transport layers or films for the duration of its storage and transport.

The privacy film can be switched over its entire surface between the above-mentioned transparent and privacy protection state. The alternative provision of non-switchable surface areas, which can be simply transparent or tinted, for example, makes it possible to cover the entire window pane with the privacy film in a uniform installation process as described here and, if necessary, to leave a non-switchable part area in addition to a switchable part area.

To attach the privacy film along the sides of the window frame, the installation kit includes one or more clamping strips that can be cut to the respective lengths of the frame sides, which are self-adhesive on the back and designed on the front for replaceable clamping of the privacy film. The individual clamping strips extend in a straight line and can be rolled up lengthwise into a space-saving roll of a predetermined minimum diameter, particularly for storage and/or transport, if the clamping strips have the necessary flexibility and their clamping functionality is not impaired. For example, standard household or paper scissors can be used to cut the clamping strips to the required lengths. Alternatively or additionally, a suitable cutting tool can also be included in the installation kit.

Furthermore, the assembly kit includes a corner clamping bracket for each frame corner, which is self-adhesive on the back and designed for replaceable clamping of the privacy film on the front, and whose angle legs are geometrically shaped so that they can be clearly positioned on both sides of the frame in the respective corner by mechanical stop or by alignment. Each corner clamping bracket also has several straight edges, marking lines and/or projections for clear positioning of the clamping strips to be attached to the corner clamping bracket and the privacy film to be clamped in the corner clamping bracket. In particular, the length and installation position of each clamping strip to be cut by the user is clearly defined by aligning the cut clamping strip with its narrow sides to the straight edges, marking lines and/or projections provided for this purpose on the corner clamping brackets glued to both corners of one side of the frame and/or placing it up to a mechanical stop. At least two corner clamping brackets are designed to contact the electrodes of the privacy film.

The construction of the corner clamping brackets described here enables a clear positioning of the corner clamping brackets in the frame corners and a clear determination of the size and position of the clamping strips extending between two corner clamping brackets as well as the privacy film to be clamped into the corner clamping brackets and the clamping strips. This enables a user without any previous manual knowledge to easily and error-free install the switchable privacy film on a window with individual frame dimensions.

As already mentioned, the assembly kit further comprises the electronic control element presented here, which is designed to be connected to the at least two corner clamping brackets that serve to contact the electrodes of the privacy film, and for the user to switch the privacy film between its transparent and privacy protection state. For this purpose, the control element can, for example, have one or more push or rotary buttons, levers or a touch screen for user input. Furthermore, on the output side, it can have, for example, a connecting cable or a socket for plugging in a connecting cable for connection to a corner clamping bracket and on the input side, a power supply unit and/or a power plug and/or a connecting cable or an associated socket for connecting a separately designed power supply unit, so that when the privacy screen film is operated, for example, an input voltage available in the supply network of, for example, about 220-240 V and about 50-60 Hz is converted in the power supply unit into a suitable input direct voltage of, for example, about 22 V to 36 V, in particular about 24 V to 26 V, for the control element. In the control element, this direct voltage is in turn converted into an alternating voltage suitable for controlling the film of, for example, about 15 V to about 25 V, in particular about 18 V to about 19 V, and an alternating voltage frequency of about 40 Hz to about 60 Hz, in particular about 50 Hz, as described further above and further below. The control element can be designed to be mounted near the window, for example on or under a windowsill or on the window frame or on an adjacent wall, and for this purpose can comprise, for example, self-adhesive fastening elements or fastening elements that can be mounted with other fastening means such as screws, etc.

In particular, each corner clamping bracket and/or each clamping strip can have two clamping halves for interchangeable clamping of the privacy film between them. The first of the two clamping halves is self-adhesive on the back for attachment to a smooth surface, such as a pane or a window frame. The two clamp halves are either designed separately from one another or are connected to one another via a hinge-like and/or flexible connection, for example a film hinge. The second clamp half can therefore be folded away from or removed from the first clamp half glued to the window in order to insert or replace the privacy film and to position it correctly in the corner clamp angle or the clamping strip.

The two clamp halves can be releasably fixed to one another by a click or snap-in closure in the form of locking elements designed to interlock and snap into place in both clamp halves and/or by a magnetic attraction force of magnetic elements designed to overlap one another in both clamp halves, so that a predetermined clamping force is applied to the privacy film. The required clamping effect can vary depending on the application and the dimensions of the privacy film. The clamping effect to be applied by the corner clamp angles and the terminal strips must be dimensioned in such a way that both the electrical contact of the electrodes and the holding of the film over a predetermined period of time, for example several months or years, are reliably guaranteed.

The clamping effect on the privacy film in the corner clamping brackets on the one hand and in the clamping strips on the other hand can be based on a similar or fundamentally different clamping construction. For example, the corner clamping brackets can each have one or more click or snap fasteners, while the clamping effect in the clamping strips is based on magnetic elements, or vice versa. Both of these clamping constructions can also be combined in a corner clamping bracket or in a clamping strip.

With the fastening principle of the privacy film described here, clamping it into the corner clamping brackets and the clamping strips ensures in particular that a predetermined distance in the direction perpendicular to the pane and film surface always remains between the window pane and the privacy film mounted on the window. This distance is determined by the thickness of the first clamping half of the respective corner clamping bracket or the respective clamping strip glued to the window pane or window frame. When fastening to the window frame, the thickness of the frame in the direction perpendicular to the pane surface is also added.

In particular, suitable dimensions of the corner clamping brackets and the clamping strips can ensure that an air layer of a predetermined thickness remains between the installed privacy film and the window pane. This can reliably prevent the privacy film from coming into contact with the surface of the pane in an uncontrolled manner or from sticking statically, thereby causing trapped air bubbles to form or for humidity or condensation to collect and not be able to escape to the outside. In order to allow any humidity or condensation to escape or drain to the outside, suitable through holes or recesses can be formed in all or, for example, at least in the corner clamping brackets and/or clamping strips to be installed at the bottom. This can help to reliably prevent a short circuit between the electrically conductive layers of the film, particularly in their edge areas.

In particular, those corner clamping brackets that are intended for contacting the electrodes can, for example, each have an electronic circuit board that is equipped with connectors and/or supply lines for connecting to the electronic control element and with electrical contacts for connecting/pressing onto the electrodes of the privacy screen film. The electrical contacts are designed to rest with a contact pressure on the respective electrode after the aforementioned positioning and clamping of the privacy screen film in the corner clamping bracket. They can in particular be designed as spring contacts in order to ensure additional contact pressure on the electrodes for a reliable electrical connection. The respective circuit board can in particular extend over a large part or over the entire surface of the corner clamping bracket in order to use the corner clamping bracket as efficiently as possible for clamping and electrically contacting the privacy screen film at the same time.

According to one embodiment, each corner clamping bracket is formed by two angle legs in the form of straight strips that are connected to one another in one piece and extend at a predetermined angle of, for example, 90° to one another. The predetermined angle that the straight angle legs of a corner clamping bracket form to one another can in particular correspond to an angle that both sides of the window frame form to one another in the relevant frame corner and that can be, for example, 90° or, in the case of non-rectangular window frames, can also be any other acute or obtuse angle. In this case, a corner clamping bracket in the associated frame corner is, for example, formed by a Can be clearly positioned by means of a mechanical stop on the outside of the leg or by aligning both angle legs on the inside of the leg with their entire length on each side of the frame.

As an alternative to this embodiment, the angle legs can also be designed to be straight, for example, only in a partial section of their longitudinal extension or only on the inside or outside of the leg, which, just as with the above strip-shaped angle legs, can serve to ensure clear positioning in a frame corner.

According to a further embodiment, which can be combined with the other embodiments, each angle leg of each corner clamping angle has a straight edge at its end facing away from the corner, to which a clamping strip can be placed and aligned with its narrow side, which is also straight. This allows a clamping strip to be cut and positioned in a clear manner between two corner clamping angles that are glued to both sides of a frame side of the window frame. Furthermore, this also makes it possible to achieve a continuous clamping effect on the privacy film along the entire circumference of the frame.

Alternatively or in addition to this embodiment, each angle leg of each corner clamping angle in its clamped state, in which a privacy film is clamped therein, can have essentially the same width along the film surface in a direction orthogonal to its edge as the clamping strip to be applied to this angle leg in its clamped state, in which a privacy film is clamped therein. This makes it possible in particular to achieve a continuous and/or essentially uniform clamping effect on the privacy film along the entire frame circumference.

According to a further embodiment, which can be combined with the other embodiments, each angle leg of each corner clamping angle has a straight marking or a straight projection for positioning and aligning a straight edge of the privacy film to be clamped in the corner clamping angle. The position of the straight marking or the straight projection is designed in such a way that a clamping effect sufficient to hold the privacy film on the privacy film clamped in the corner clamping angle and a reliable electrical contact of its electrodes is ensured.

In particular, the electronic control element can be designed for the user to vary the electrical voltage applied to the electrodes, for example in the case of a PDLC film to vary the degree of alignment of liquid crystals. As already mentioned, this can be implemented in the present control circuit and the present control method, for example, via a suitable change in a PWM control signal for the two step-down converters. This allows the privacy protection film to be switched between privacy protection states with varying degrees of privacy protection for visible light by applying different levels of electrical voltage. In other words, the privacy protection film in this design can be dimmed by varying the applied electrical voltage.

According to one embodiment, the assembly kit further comprises a connecting cable for electrically connecting the two corner clamping brackets, each of which is to be contacted with an electrode of the privacy film, or the electronic circuit boards contained therein. For this purpose, the two corner clamping brackets mentioned each have at least one connector for this connecting cable. The connector can be designed, for example, as an insulation displacement terminal or insulation displacement socket, into which the respective end of the connecting cable can be easily plugged and is thereby electrically contacted and mechanically held with the corner clamping bracket or its circuit board without the use of tools or screws. One of these corner clamping brackets also has a supply line for connection to the electronic control element.

According to one embodiment, the installation kit further comprises a graph paper or other type of grid pattern paper (for example, approximately the size of the film) as a cutting aid for aligning and cutting the privacy film to the individually required window size. Alternatively or additionally, the installation kit can further comprise an adhesive mounting tape that is designed to temporarily fix the unfolded clamping halves of the clamping strips to the window frame and/or the graph paper or the grid pattern paper to the film for the duration of the installation. Alternatively, the graph/grid pattern paper can also be provided, for example, as a removable protective layer on the privacy film.

According to one embodiment, the mounting kit further comprises a remote control unit which has an operating element, such as one or more push or rotary buttons, levers or a touch screen, for the user to switch the privacy film between its transparent and privacy protection state. The remote control unit is designed to wirelessly transmit the user's switching inputs to the Control element designed to control the privacy film accordingly. This allows the user to switch the privacy film between its transparent and privacy protection state from a distance of, for example, a few meters from the window.

• Zunächst wird in jeder Rahmenecke je ein Eckklemmwinkel angebracht, indem jeder Eckklemmwinkel durch einen mechanischen Anschlag beider Winkelschenkel gegen beide Rahmenseiten in der jeweiligen Ecke eindeutig positioniert und mit seiner selbstklebenden Rückseite auf der Fensterscheibe aufgeklebt wird oder indem jeder Eckklemmwinkel auf dem Rahmen selbst in der jeweiligen Ecke dadurch eindeutig positioniert wird, dass der Fensterscheibe zugewandte Innenkanten beider Winkelschenkel mit der Fensterscheibe zugewandten Innenkanten beider Rahmenseiten fluchten, und mit seiner selbstklebenden Rückseite auf dem Rahmen aufgeklebt wird. Dabei werden die genannten zwei Eckklemmwinkel, die zur Kontaktierung der Elektroden vorgesehen sind, sinnvollerweise in denjenigen Rahmenecken angeordnet, in die sich auch die Folienabschnitte mit den Elektroden erstrecken sollen.

A suitable sequence of installation steps for attaching a switchable privacy film to a window using the installation kit presented here can be as follows, for example, whereby further (intermediate) steps can also be added if necessary:

• First, a corner clamping bracket is attached to each corner of the frame by clearly positioning each corner clamping bracket in the respective corner by mechanically stopping both angle legs against both sides of the frame and then gluing it to the window pane with its self-adhesive back, or by clearly positioning each corner clamping bracket on the frame itself in the respective corner by aligning the inner edges of both angle legs facing the window pane with the inner edges of both frame sides facing the window pane and then gluing it to the frame with its self-adhesive back. The two corner clamping brackets mentioned, which are intended for contacting the electrodes, are sensibly arranged in the corners of the frame into which the film sections with the electrodes are also to extend.

Then the one or more clamping strips are cut to the lengths of the frame sides in such a way that the respective cut clamping strip section in its clamping state mentioned above rests with its two narrow sides on the opposite ends (i.e. edges) of the angle legs of the corner clamping angles, which are glued to the frame corners on both sides of the relevant frame side. The clamping strip section rests with its entire long side on the frame side or is flush with its inner edge, similar to the angle legs of the corner clamping angles. In other words, the angle legs of the opposite corner clamping angles merge almost seamlessly into the clamping strip section arranged between them.

After this positioning and the appropriate cutting of the individual clamping strip sections, they are glued with their self-adhesive backs in these clear positions on the window pane or on the frame.

In a further step, the privacy film is cut to the individual window size so that it is clearly positioned in each corner of the frame by aligning its two edges with the straight marking lines provided for this purpose and/or projections of the corner clamping bracket glued to it. If necessary, the enclosed millimeter or grid pattern paper can first be clearly positioned and cut in this way instead of the privacy film, after which the cut paper is placed on the privacy film in order to cut it accordingly.

Finally, any removable transport protection layers are removed from the privacy film that has been cut to size, whereupon the privacy film is positioned and clamped in the described clear manner with regard to all glued corner clamping angles and the clamping strip sections extending between them.

In a specific embodiment, the electrodes on and along an edge of the privacy film can extend from a corner of the film to a predetermined distance from one another, which is measured along the surface of the film. If one side of the window frame is designed as a hinge side for opening the window, then in this embodiment the two corner clamping angles, which are provided for contacting the electrodes, can advantageously be glued to frame corners that are located opposite one another on the hinge side.

According to one embodiment, the two corner clamping brackets, each of which is to be contacted with an electrode of the privacy film, are connected to one another by the connecting cable before the film is inserted and clamped in place. The connecting cable can be guided between the two corner clamping brackets within the clamping strip section that extends between them, to the side of the privacy film to be clamped in. In this way, after the privacy film has been clamped in place, the connecting cable remains hidden in the clamped state of the aforementioned clamping strip section and is thus mechanically protected from the outside, among other things.

The present invention further relates to a use of the mounting kit presented here for a residue-free, removable and replaceable attachment of a switchable privacy film to a window in private or business rooms, such as a bedroom, a bathroom, a kitchen, an entrance area, a study or a meeting room, and much more.

Further details and features emerge from the following description of preferred embodiments in conjunction with the subclaims. The respective features can be implemented alone or in combination with one another. The possibilities for solving the problem are not limited to the embodiments.

• 1 eine Übersichtsdarstellung eines Montage-Kits nach einer Ausführung der Erfindung zum auswechselbaren Anbringen einer Sichtschutz-Folie an einem Fenster, wobei einzelne Bestandteile des Kits teils in Draufsicht, teils perspektivisch dargestellt sind;
• 2a einen Fensterausschnitt mit einer ersten Winkel-Klemmhälfte eines Eckklemmwinkels des Montage-Kits der 1, nachdem sie in einer zugehörigen eindeutigen Position in einer linken unteren Rahmenecke des Fensters aufgeklebt wurde;
• 2b das Fenster, nachdem auch die übrigen drei ersten Winkel-Klemmhälften aus der 1 in ihren eindeutigen Positionen in den übrigen drei Rahmenecken aufgeklebt wurden;
• 3a-3e darauffolgende Montageschritte, bei denen die Klemmleisten des Montage-Kits der 1 auf die benötigten Längen zugeschnitten und in jeweils zugehörigen eindeutigen Positionen an zugehörigen Rahmenseiten des Fensters befestigt werden;
• 4a-4c das Zuschneiden eines Millimeterpapiers des Montage-Kits der 1 auf eine für die Sichtschutz-Folie durch die angeklebten Winkel-Klemmhälften eindeutig vorgegebene Größe;
• 5a-5c das anschließende Zuschneiden der Sichtschutz-Folie 3 unter Verwendung des gemäß 4a-4c zugeschnittenen Millimeterpapiers;
• 6a-6b das elektrische Verbinden beider Eckklemmwinkel, die für die Kontaktierung von Elektroden der Sichtschutz-Folie vorgesehen sind, durch ein Verbindungskabel des Montage-Kits 1 der 1;
• 7a-7b das anschließende Anbringen der Sichtschutz-Folie durch das Einklemmen in allen vier am Fenster befestigten Eckklemmwinkeln und Klemmleisten des Montage-Kits 1 der 1;
• 8 ein Beispiel dafür, wie ein Ansteuerungselement des Montage-Kits 1 der 1 in der Nähe eines Fensterscharniers abnehmbar befestigt werden kann;
• 9 das Fenster, nachdem die Sichtschutz-Folie daran gemäß einer Ausführungsform des Verfahrens unter Verwendung des Montage-Kits 1 der 1 montiert wurde;
• 10 in einem Querschnitt entlang einer Linie B-B in 9 einen Ausschnitt des Fensters mit der daran montierten Sichtschutz-Folie im Bereich der rechten unteren Rahmenecke; und
• 11 ein schematisches Schaltbild einer Steuerungsschaltung gemäß einem Ausführungsbeispiel der Erfindung, die in einem Ansteuerungselement des Montage-Kits der 1 implementiert sein kann.

The embodiments are shown schematically in the figures, whereby the individual figures can also be understood as being true to scale, but are not limited to this. The same reference symbols in the individual figures designate the same or functionally identical elements or elements that correspond to one another in terms of their functions. Not all elements are provided with reference symbols. Different views of the same elements could be scaled differently. In detail, partly in plan view and partly in perspective:

• 1 an overview of a mounting kit according to an embodiment of the invention for the replaceable attachment of a privacy film to a window, wherein individual components of the kit are shown partly in plan view, partly in perspective;
• 2a a window cutout with a first angle clamp half of a corner clamp angle of the mounting kit of the 1 after it has been glued in a corresponding unique position in a lower left corner of the window frame;
• 2 B the window after the remaining three first angle clamp halves have been removed from the 1 were glued in their clear positions in the remaining three corners of the frame;
• 3a-3e subsequent assembly steps, in which the terminal blocks of the assembly kit of the 1 cut to the required lengths and attached in respective unique positions on the corresponding frame sides of the window;
• 4a-4c Cutting a millimeter paper of the assembly kit of the 1 to a size that is clearly defined for the privacy film by the glued-on angle clamp halves;
• 5a-5c the subsequent cutting of the privacy film 3 using the 4a-4c cut graph paper;
• 6a-6b the electrical connection of both corner clamping brackets, which are intended for contacting electrodes of the privacy film, by means of a connection cable from the mounting kit 1 of the 1 ;
• 7a-7b the subsequent attachment of the privacy film by clamping it in all four corner clamping brackets and clamping strips of the mounting kit 1 of the 1 ;
• 8th an example of how a control element of the mounting kit 1 of the 1 can be removably attached near a window hinge;
• 9 the window after the privacy film has been applied thereto according to an embodiment of the method using the mounting kit 1 of 1 was assembled;
• 10 in a cross section along a line BB in 9 a section of the window with the privacy film mounted on it in the area of the lower right corner of the frame; and
• 11 a schematic diagram of a control circuit according to an embodiment of the invention, which is used in a control element of the mounting kit of the 1 can be implemented.

1 shows a schematic overview of an assembly kit 1 according to an embodiment of the invention. Individual components of the kit 1 are shown in a top view or perspective, as they may be spread out on a table, for example, after they have been taken out of a compact transport box 2, in this example made of recycled cardboard or carton. The transport box 2 can (but does not have to) also be regarded as part of the assembly kit 1 and is designed and dimensioned in such a way that all components of the assembly kit 1 described below fit into it in the most space-saving way possible in order to be transported or stored intact.

The assembly kit 1 comprises firstly a privacy film 3 that can be cut to the respective window size and which in this example can be switched over its entire surface between a transparent state and a privacy protection state and for this purpose comprises an electrically switchable layer between two electrically conductive layers (not shown individually), each of which is connected to an electrode 3a and 3b for applying electrical voltage between them. The privacy film 3 can be a PDLC film mentioned above purely by way of example.

In this example, the electrodes 3a and 3b extend on and along an edge side 3c of the privacy film 3 from a corner of the film to a predetermined distance from each other, which is measured along the surface of the film, which is, for example, approximately one third, one half or an entire length of the individual electrode 3a or 3b in the foil surface.

The privacy film 3 can be provided in the assembly kit 1, for example, in a rectangular shape of a predetermined size and can be rolled up for the duration of storage and transport, for example, into a space-saving roll with a predetermined roll diameter in which the electrical functionality remains unaffected. Suitable film sizes can be, for example, about 0.8 m × 0.6 m for bathroom windows, about 1.3 m × 1.5 m for smaller bedroom windows, about 1 m × 2.2 m for large narrow ("French") windows, or any other size with side lengths, for example, between about 0.5 m and about 3.5 m, in order to be applicable to window panes of the same or a slightly smaller size.

The assembly kit 1 also includes one or more, in this example four, clamping strips 4, which can be cut to the respective lengths of the frame sides. The clamping strips 4 are self-adhesive on the back and are designed on the front for the replaceable clamping of the privacy film 3. This functionality is explained further below with reference to 3c-3d, 6a-6b explained. The individual terminal strips 4 extend in a straight line and can be rolled up longitudinally into a space-saving roll of a predetermined minimum diameter, in particular for their storage and/or transport, if the terminal strips 4 have the necessary flexibility for this and their clamping functionality is not impaired thereby.

As in 1 As indicated, the mounting kit 1 includes for each frame corner 16a (see 2a-2b) of a rectangular window frame 16 in this example, a corner clamping angle 5 composed of three parts 5a, 5b and 5c (cf. 7c ) is provided which, in its assembled state, is self-adhesive on the back and is designed on the front for replaceable clamping of the privacy film 3 and whose angle legs 7a and 7b are geometrically shaped such that they can be clearly positioned on both frame sides 16b in the respective corner 16a by mechanical stop or by alignment.

As in 7c illustrated, each corner clamping bracket 5 is composed purely by way of example of three separate parts as follows: a first angle clamping half 5a, which is self-adhesive on the back and has an electronic circuit board for contacting the electrodes 3a or 3b in the respective corner if required, a second angle clamping half 5b, which is attached to the first angle clamping half 5a by means of a click or snap-in closure (see 7c ) can be releasably fixed so that a predetermined clamping force is applied to the privacy film 3 positioned between them, and an angle cover part 5c, which in the clamped state of the corner clamping angle 5 on the clamping halves 5a and 5b fixed to each other (again by a click or snap closure, see 7c ) can be releasably fixed. For clear positioning in a rectangular frame corner 16a, in this example each corner clamping angle 5 (in particular its first angle clamping half 5a which is self-adhesive on the back) is formed by two angle legs 7a and 7b which are connected to one another in one piece and are in the form of straight strips which extend at a right angle to one another.

As in 1 As shown, each angle leg 7a and 7b of each corner clamping angle 5 has along the film surface in a direction orthogonal to its edge essentially the same width as the clamping strip 4 to be applied to this angle leg 7a or 7b in its clamping state according to 1 This makes it possible to achieve a continuous and uniform clamping effect on the privacy film 3 along the entire circumference of the frame.

The assembly kit 1 further comprises an electronic control element 6 (also referred to herein as a control box) which is designed for the user to switch the privacy film 3 between its transparent and privacy protection state. For this purpose, the control element can have, for example, one or more push or rotary buttons, levers or a touch screen for user-side switching inputs. The control element 6 is designed for connection to one of the corner clamping brackets 5, which for this purpose has a supply line 5d with a plug connector 5e. For this purpose, the control element 6 has a socket (not shown) on the output side for plugging in the plug connector 5e of the supply line 5d for connection to the associated corner clamping bracket 5 and a power supply unit 6a with a power plug 6b on the input side (which can be connected to the control box via an associated connection cable with a plug). In this example, the control element is designed to be attached near the window, for example on or under a window sill or on the window frame or on an adjacent wall. For this purpose, the mounting kit 1 provides a rectangular holding plate 6c with clip-on webs or similar mechanical fastening devices, purely as an example, so that the control element 6 can be removably attached to the holding plate 6c, whereby the holding plate 6c can be attached, for example, to a smooth surface such as a window sill in a manner that can be removed without leaving any residue using a double-sided self-adhesive strip 6d (also referred to herein as a power strip). The Fixing plate 6c to wallpaper, woodchip, plaster etc. is possible with strip 6d.

In this example, the assembly kit 1 also includes a connecting cable 8 for electrically connecting two corner clamping brackets 5 (or the electronic circuit boards contained therein) to each other, each of which is to be contacted with an electrode 3a/3b of the privacy film 3. In this example, all corner clamping brackets 5 (cf. 2a , 6a and 6b) on each angle leg 7a and 7b there is a connector 9 for the connecting cable 8. In this example, the connector 9 is designed as an insulation displacement socket into which the respective end of the connecting cable 8 can be easily inserted and is thereby electrically contacted with the corner clamping bracket 5 or its circuit board and at the same time mechanically held therein without the use of tools or screws.

Furthermore, the assembly kit 1 in this example includes a millimeter paper 10 as a cutting aid for aligning and cutting the privacy film 3 to the individually required window pane size. Furthermore, the assembly kit 1 optionally includes an adhesive assembly tape 11, which is designed to temporarily fix the unfolded clamping halves of the clamping strips 4 to the window frame and/or the millimeter paper 10 to the film 3 for the duration of the assembly.

Finally, in this example, the assembly kit 1 includes a remote control unit 12, which has an operating element 14, here purely in the form of a push button, for the user to switch the privacy film 3 between its transparent and privacy protection state. The remote control unit 12 is designed to wirelessly transmit the user's switching inputs to the control element 6 for the corresponding control of the privacy film 3.

The following is based on the 2a-10 an embodiment of the above-mentioned mounting method for attaching a switchable privacy film 3 to a window whose frame 16 has four rectangular corners 16a and straight sides 16b extending therebetween, using the mounting kit 1 of 1 described.

Before starting the assembly, it may be advantageous to remove the contents of the transport box 2, ie all the components of the assembly kit 1 described above, from the box 2 and store them at room temperature as described in 1 shown on a flat surface, for example a table. If individual components such as the foil 3, the terminal strips 4 and/or the graph paper 10 were transported or stored in a rolled-up state, it is advisable to lay them out flat and let them relax for 24 hours, for example. Alternatively, each terminal strip 4, if it is in a 3c If the product has been transported and stored in a recognizable unfolded state and, where appropriate, as a roll, it should be smoothed out on a flat surface such as a table with the thumb and aligned straight in its lengthwise direction.

As in 3c-3d, 6a-6b As shown, in this example each terminal block 4 is composed in the transverse direction of two clamping halves 4a and 4b connected to each other by a film hinge 4c, which are arranged in the 1 shown clamping state, lie congruently on top of each other, with the privacy screen film 3 being clamped between them. A first clamp half 4a (in 1 hidden, see 3c-3d, 6a-6b) for attachment to a smooth surface, such as a window pane, self-adhesive on the back and, as in 3d shown, is additionally protected from the outside by a removable protective strip 4d before installation. The second clamp half 4b can therefore be folded away from the first clamp half 4a, which is glued to the window (during installation), in order to insert or replace the privacy film 3.

In this example, the two clamping halves 4a and 4b can be releasably fixed to each other by a magnetic attraction force, which is formed by magnetic elements 15a and 15b overlapping each other in both clamping halves 4a/4b (see 3d ) is generated so that a predetermined clamping force is applied to the privacy film 3 positioned between them. This clamping force holds the privacy film 3 in its mounted state on the window (see 7a-7b and 9-10 ) is held in the position described below between the respective corner clamping angles 5.

As a further preparatory step before installation on the window, each clamping strip 4 is pushed along the film hinge 4c to its 1 shown clamped state, wherein the fold line 4e can also be traced with a thumb and/or index finger so that it forms a straight edge for attachment to a likewise straight inner edge 16d of the respective frame side 16b.

Furthermore, in this example, the glass surface of the window pane 16c to be equipped with the film 3 (cf. 2a-2b) cleaned in preparation for assembly. As a further preparatory step, in this example, a removable protective strip (not shown) is removed from the self-adhesive back of each first angle clamping half 5a in order to stick the first angle clamping halves 5a onto the window pane 16c.

2a shows the first angle clamp half 5a of the 1 , after it has been glued in the corresponding, unique position in the lower left corner of the frame 16a. As mentioned above, the first angle clamp half 5a is clearly positioned in the frame corner 16a in that its two straight angle legs 7a and 7b rest with their outer edges up to a mechanical stop on straight inner edges 16d in the frame corner 16a.

In this example, the drawing layer of the 2a left side 16b of the window frame 16 is designed as a hinge side with a hinge 17 for opening the window. Therefore, two corner clamping brackets 5, which are provided for contacting the electrodes 3a and 3b of the privacy film 3, are advantageously glued purely by way of example in both left frame corners 16a.

2 B shows the window after the remaining three first angle clamp halves 5a of the 1 were glued in an analogous manner in their unique positions in the other three frame corners 16a.

3a-3e show subsequent assembly steps in which the terminal blocks 4 of the 1 cut to the required lengths and fastened in the corresponding, unique positions on the frame sides 16b.

How 3a shows, in this example, one of the terminal blocks 4 (in its clamping state according to 1 ) with its first narrow side 18 rests against a straight edge 19 formed by the free end of the angle leg 7a of the first angle clamp half 5a, which is glued in the upper left corner of the frame 16a. As in 3b shown, the required length of the clamping strip 4 is then marked with a pen so that its second narrow side 20 also rests against the opposite straight edge 21 of the first angle clamping half 5a glued to the lower left corner 16a of the frame, as far as it will go, and thus fits as precisely as possible between the two opposite corner clamping angles 5 on the hinge side. As shown in 3c As shown, the terminal block 4 is then opened up and cut to the length shown using household or paper scissors.

As in 3d shown, the cut clamping strip 4 is then folded back into its clamped state and positioned on the frame side 16b in a clear position in which it is placed with its narrow side 18 as far as it will go against the edge 19 of the upper left first angle clamping half 5a and is also brought as far as it will go against the fold line 4e on the inner edge 16d of the frame side 16b. The protective strip 4d is then gradually peeled off from top to bottom on the self-adhesive back of the clamping strip and the clamping strip 4 is immediately pressed against the window pane 16c with the exposed section of its self-adhesive back until it is glued along its entire length between the two corner clamping angles 5 on the hinge side of the window in the position mentioned. These steps are then carried out on the other three frame sides 16b, and 3e shows the result.

4a to 4c show the cutting of the millimeter paper 10 to the required pane size in the position clearly specified for the privacy film 3 by the glued-on angle clamp halves 5a. The millimeter paper 10 serves as an optional cutting aid in order to make the determination of the clearly predetermined position and the subsequent cutting process for the privacy film 3 as easy as possible.

How 4a using the example of the upper left corner of the frame 16a, the straight edges of a rectangular corner of the millimeter paper 10 are first aligned with the straight marking lines 22 provided specifically for this purpose on each angle leg 7a and 7b. In this example, each angle leg 7a or 7b of each corner clamping angle 5 has a marking line 22 which extends over a large part of its length in its direction of extension, ie approximately parallel to the inner edge of the frame 16d, against which it rests until it stops. As in 4b shown, the required height of the millimeter paper 10 is then determined in the lower left corner 16a of the frame by transferring a marking line 22 of the corner clamping angle 5 glued to this corner 16a onto the millimeter paper 10 with a pen (ie a cutting mark is drawn in) in order to align this corner of the millimeter paper 10 at the same time as the upper left corner in the same unambiguous manner to the straight marking lines 22. In a similar way, according to 4c The required length of the millimeter paper 10 is also determined using the straight marking lines 22 of the corner clamping bracket 5 glued to the top right corner 16a of the frame and transferred to the millimeter paper 10 as a cutting mark, whereupon the millimeter paper 10 is cut along its line grid using household or paper scissors according to the cutting marks drawn in (not shown separately) and thus receives a shape and size intended for the privacy film 3. The correct cutting can then be done nd by holding the millimeter paper 10 against the window pane 16c (cf. 2 B) in the above-mentioned clearly intended position in all four frame corners 16a by means of the marking lines 22 provided therein on the corner clamping angles 5 (or in this embodiment on their first angle clamping halves 5a).

5a to 5c show an example of how the privacy film 3 can be subsequently applied using the 4a-4c cut to size using the millimeter paper 10. As shown in 5a As shown, the cut millimeter paper 10 is placed on the privacy film 3 of the 1 placed so that its long side 10a, which is in 4a-4c was positioned on the hinge side of the window, is aligned flush with the edge side 3c of the privacy film 3, on which the electrodes 3a and 3b are formed. In order to achieve the best possible electrical functionality of the privacy film 3, the two short sides 10b of the millimeter paper 10 are advantageously approximately the same distance (each indicated as edge distance A) from the edge sides 3d of the film 3 adjacent to the edge side 3c.

As in 5b shown, the millimeter paper 10 can be temporarily fixed in this position on the privacy film 3 with the mounting adhesive tape 11 in order to then cut the privacy film 3 to the size of the millimeter paper 10 with household or paper scissors, as shown in 5c indicated.

6a and 6b show an example of how the two corner clamps 5, which are intended for contacting the electrodes 3a and 3b, are electrically connected to each other by the connecting cable 8. As in 6a As can be seen from the example of the hinge side of the window, in this example all the clamping strips 4 glued to the window pane 16c are first removed from their 3e shown clamping state and their second clamping halves 4b are temporarily fixed to the corresponding frame sides 16b by means of the mounting adhesive tape 11 (in order to later be able to position and clamp the privacy film 3 in each clamping strip 4 between its first clamping half 4a and its second clamping half 4b, cf. 7a) . Then one end of the connecting cable 8 is inserted into the downward-facing connector 9 of the corner clamping bracket 5 glued to the upper left corner of the frame 16a. The connecting cable 8 clamps into it without tools, screws or the like. As shown in 6b As shown, the connecting cable 8 is then guided in a groove formed by the film hinge 4c within the unfolded terminal strip 4 on the same side of the frame (in this example, the hinge side of the window), folded once or several times in the case of excess length, and inserted with the second end into the upwardly pointing connector 8 of the corner clamping bracket 5 glued into the lower left corner of the frame 16a.

7a and 7b show the subsequent attachment of the privacy film 3 by clamping it in all four corner clamping brackets 5 and clamping strips 4 attached to the window. To do this, any removable transport films that may be present are first removed from the privacy film 3. The privacy film 3 is then clearly aligned with its edge in the area of all four first angle clamping halves 5a on their straight marking lines 22 as described above. All clamping strips 4 can then be folded shut in their clamped state, whereby the privacy film 3 is clamped and held in place, as shown in 7a in the upper right section of the window. As in 7a-7c shown, the second angle clamp half 5b is then fixed to the first angle clamp half 5a in each corner 16a by the click or snap lock provided therein, whereby the privacy film 3 is also clamped in between. As shown in 7b-7c As shown, the angle cover part 5c is then fixed in each corner 16a on the clamping halves 5a and 5b which are fixed to one another.

As in 7b As shown, the cover part 5c of at least those corner clamping brackets 5 that are to be mounted in the lower frame corners 16a can have a recess 27, for example in the form of a cut-off angle corner, in order to allow any air humidity or condensate to escape or flow out of the corner clamping bracket 5 to the outside. This can contribute to reliably preventing a short circuit between the electrically conductive layers of the privacy film 3, in particular in their edge areas.

7c illustrates again in a perspective exploded view the above-mentioned three-part structure of each corner clamp angle 5 of the assembly kit 1 of the 1 using the example of the corner clamping bracket 5 provided with the supply line 5d from the 1 .

As mentioned above, in this example each corner clamping bracket 5 is composed of three parts which can be removed from one another and which are essentially identical: a first angle clamping half 5a, a second angle clamping half 5b which can be releasably fixed to the first angle clamping half 5a by means of a click or snap-in closure in the form of closure elements 23 designed in both clamping halves to engage and snap into one another, and an angle cover part 5c which can be fixed to the can be releasably fixed to one another by means of the clamping halves 5a and 5b, in this example again by means of a mechanical click or snap-in closure, which can be formed in particular by interlocking and snap-in locking elements 24 on the edge of the cover part 5c and the second angle clamping half 5b.

The second angle clamp half 5b can therefore be removed from the first angle clamp half 5a glued to the window in order to insert or replace the privacy film 3 and, as described herein, can be clearly identified in the corner clamp angle 5 using the marking lines 22 drawn or embossed on the user-side surface of the first angle clamp half 5a (see 4a-4c and 7a) to position.

In the mounting kit 1 of the 1 Each corner clamping bracket 5 can be used to contact the electrodes 3a and 3b of the privacy film 3. For this purpose, the respective first angle clamping half 5a has an electronic circuit board 25, which in this example is equipped on each angle leg 7a and 7b with a connector 9 for the connecting cable 8 and with four electrical spring contacts 26 for connecting/pressing onto the electrode 3a or 3b of the privacy film 3. One of the corner clamping brackets 5 is also equipped with the supply line 5d for connecting to the electronic control element 6. In this example, the electrical spring contacts 26 are arranged offset from one another to increase the contact area. In this example, the circuit board 25 extends over almost the entire surface of the corner clamping bracket 5 in order to use it as efficiently as possible for clamping and for electrically contacting the privacy film 3 at the same time. It serves for the electrical connection between the electrical spring contacts 26 and the connectors 9 or the supply line 5d and can be designed, for example, as a two-layer FR4 board.

8th shows an example of how the control element 6 is positioned near the window hinge 17 (see 2a , 2 B) can be attached detachably by placing it on the mounting plate 6c provided for this purpose. As shown in 8th As indicated, the holding plate 6c in this example is attached to a smooth surface such as a window sill 28 by a double-sided self-adhesive strip 6d. If the entire structure is to be removed later, the self-adhesive strip 6d can be designed in particular for removal from the window sill without leaving any residue.

9 shows the window after the privacy film 3 has been attached to it as described above using the mounting kit 1 of the 1 by clamping it into the corner clamping brackets 5 and clamping strips 4 along the entire circumference of the window frame 16.

10 shows a cross section along the line BB in 9 a section of the window with the privacy film 3 mounted on it in the area of the lower right corner of the frame 16a. As can be seen from 10 As can be seen, the positioning presented here and the fastening of the privacy film 3 based on clamping by means of the corner clamping angles 5 ensures an essentially constant pane distance D of, for example, a few millimeters in the direction perpendicular to the pane and film surface between the window pane 16c and the privacy film 3. In this example, this distance results from the thickness of the first angle clamping half 5a of the respective corner clamping angle 5 glued to the window pane 16c. This makes it possible to ensure in particular that an air layer of a predetermined thickness remains between the mounted privacy film 3 and the window pane 16c. This can in particular reliably prevent the privacy film from resting on the pane surface in an uncontrolled manner in places or adhering statically, thereby forming trapped air bubbles or collecting air humidity or condensation and not being able to escape to the outside.

11 shows in a schematic block diagram a control circuit 30 according to an embodiment of the invention, which can be used for example in the control element 6 of the mounting kit 1 of the 1 to control the switchable privacy film 3 can be implemented.

The control circuit 30 has two independently controllable half-bridges 31a and 31b, each of which is connected to one of the two electrodes 3a and 3b of the privacy film 3 (see 1 ), ie are electrically connected to one of the two electrodes 3a and 3b during operation. Half-bridge 31a and half-bridge 31b are each designed as a step-down converter (also known as a step-down regulator or buck converter).

By controlling both step-down converters, the privacy protection film 3 can be switched between its transparent and privacy protection state. As already mentioned, the voltage at the respective electrode 3a or 3b can be set between 0 V and a predetermined input DC voltage VF, whereby to set the transparent state of the film 3, each of the two step-down converters can, for example, map a half-wave of a sinusoidal PWM control signal. A coil and a capacitor, which are in the respective step-down converter, are connected to the respective step-down converter. converters, smooth the voltage that results from the purely exemplary sinusoidal PWM control signal.

In principle, each electrode 3a, 3b can be controlled independently of the other electrode via the associated step-down converter. In this example, the two half-bridges/step-down converters 31a and 31b are essentially designed the same. However, this is not absolutely necessary, i.e. they can in principle also be designed differently from one another, since they can be controlled independently.

In 11 a first of the two step-down converters (ie half-bridge 31a) can be controlled to convert the input DC voltage VF into a first output AC voltage intended for the first electrode 3a of the privacy film 3 and for this purpose has a first electrically controllable switch Q1 and a second electrically controllable switch Q2, which are connected in series between a source of the first input DC voltage VF and ground, and a first second-order low-pass filter 32a with a first coil L1 and a first capacitor C1 designed to smooth the first output AC voltage.

In this example, the input DC voltage VF can be approximately 26 V and can be supplied by the power supply unit 6a of the mounting kit 1 described above (see 1 ). In this example, the power supply unit 6a is designed separately and can be connected to the control element 6 and thus to the control circuit 30 by means of a connecting cable with an associated plug. It is designed to convert an input voltage available in the supply network of, for example, approximately 220-240 V and approximately 50-60 Hz into a suitable input direct voltage of, for example, approximately 22 V to 28 V, in particular approximately 24 V to 26 V, in this example approximately 26 V, for the control element 6. Provided that the control element 6 operates with a protective extra-low voltage for damp rooms (which is a maximum of 25 V AC), the input direct voltage VF provided by the power supply unit 6a can also be, for example, approximately 35 V.

Similarly, the second step-down converter (i.e. half-bridge 31b) can also be controlled to convert the input DC voltage VF into a second output AC voltage intended for the second electrode 3b of the privacy film 3 and for this purpose has a third electrically controllable switch Q3 and a fourth electrically controllable switch Q4, which are connected in series between a source of the input DC voltage VF and ground, and a second second order low-pass filter 32b with a second coil L2 and a second capacitor C2 designed to smooth the second output AC voltage.

In this example, both coils L1 and L2 each have an inductance of about 150 µH and can be loaded with currents of about 600 mA. Both capacitors C1 and C2 each have a capacity of about 10 µF at about 50 V. Each switch Q1, Q2, Q3 and Q4 is designed as a MOSFET (metal oxide semiconductor field-effect transistor), which in this example, as usual, has a so-called intrinsic body diode (as in the 11 shown). The respective diode bridges the corresponding transistor.

• - einen Benutzereingaben-Wandler (in 11 rein symbolisch als „BUTTON“ bezeichnet), der zum Umwandeln manueller Umschalt-Eingaben eines Benutzers für die schaltbare Sichtschutz-Folie 3 in entsprechende elektrische Eingabe-Signale ausgebildet ist und beispielsweise durch einen oder mehrere Druck- oder Drehknöpfe, Hebel oder ein Touch-Screen des Ansteuerungselements 6 umgesetzt sein kann;
• - einen Benutzereingaben-Empfänger (in 11 rein symbolisch als „RF RX“ bezeichnet), der zum Empfangen und Umwandeln drahtlos übermittelter Umschalt-Eingaben eines Benutzers für die schaltbare Folie in entsprechende elektrische Eingabe-Signale ausgebildet ist, die beispielsweise von der Fernbedienungseinheit 12 des Montage-Kits 1 (s. 1) übermittelt werden können;
• - einen (Mikro-)Controller (in 11 rein symbolisch als „µ0“ bezeichnet), der an seinem Eingang zum Erhalten der genannten elektrischen Eingabe-Signale vom Benutzereingaben-Wandler und vom Benutzereingaben-Empfänger ausgebildet ist und an seinem Ausgang zum Ausgeben eines entsprechenden digitalen Ansteuerungssignals, in diesem Beispiel in Form eines sinusförmigen PWM-Signals, für die beiden Halbbrücken 31a und 31b ausgebildet ist. Es kann sich insbesondere um einen integrierten Mikrocontroller handeln; sowie
• - eine Transistor-Treiberschaltung „MOSFET DRIVER“, die an ihrem Eingang zum Erhalten des vom (Mikro-)Controller erzeugten Ansteuerungssignals für die beiden Halbbrücken 31a und 31b ausgebildet ist und an ihrem Ausgang zum Ausgeben entsprechender Gate-Ansteuerungsspannungen oder -Stromstärken für in den beiden Halbbrücken als Schalter Q1-Q4 enthaltene Transistoren (hier MOSFETs) ausgebildet ist. Es kann sich insbesondere um eine integrierte MOSFET-Treiberschaltung handeln, die sich beispielsweise in einem gemeinsamen Gehäuse mit den vier Transistoren Q1-Q4 befindet. Die Treiberschaltung stellt hierbei sicher, dass die Gates der MOSFETS (in 11) in der nötigen Zeit (die sich aus der Gate-Kapazität und der PWM-Frequenz ergibt) geladen und entladen werden. Zudem wird in diesem Beispiel über eine ebenfalls integrierte Charge-Pump (nicht gezeigt) ein nötiger Pegel für den High-Side N-MOSFET erzeugt.

Furthermore, the control circuit 30 comprises 11 purely as an example the following components:

• - a user input converter (in 11 purely symbolically referred to as “BUTTON”), which is designed to convert manual switching inputs of a user for the switchable privacy film 3 into corresponding electrical input signals and can be implemented, for example, by one or more push or rotary buttons, levers or a touch screen of the control element 6;
• - a user input receiver (in 11 purely symbolically referred to as "RF RX"), which is designed to receive and convert wirelessly transmitted switching inputs from a user for the switchable film into corresponding electrical input signals, which can be transmitted, for example, by the remote control unit 12 of the mounting kit 1 (see 1 ) can be transmitted;
• - a (micro)controller (in 11 purely symbolically referred to as "µ0"), which is designed at its input to receive the said electrical input signals from the user input converter and the user input receiver and is designed at its output to output a corresponding digital control signal, in this example in the form of a sinusoidal PWM signal, for the two half-bridges 31a and 31b. It can in particular be an integrated microcontroller; and
• - a transistor driver circuit “MOSFET DRIVER”, which is designed at its input to receive the control signal generated by the (micro)controller for the two half bridges 31a and 31b and at its output to output corresponding gate control voltages or currents for the two half bridges are formed as switches Q1-Q4 of transistors (in this case MOSFETs). In particular, it can be an integrated MOSFET driver circuit, which is located, for example, in a common housing with the four transistors Q1-Q4. The driver circuit ensures that the gates of the MOSFETs (in 11 ) are charged and discharged in the required time (which results from the gate capacitance and the PWM frequency). In addition, in this example a required level for the high-side N-MOSFET is generated via an integrated charge pump (not shown).

In this example, most of these components are each connected between a DC voltage source of a third input DC voltage VCC and ground. This input DC voltage VCC can in particular be between about 2 V and about 5 V, in this example about 3.3 V. It can be provided, for example, by a DC-DC converter (not shown) integrated in the control element 6, which receives a voltage from the power supply 6a of the assembly kit 1 (see. 1 ) provided power supply output voltage of, for example, about 26 V is transformed into the required third input DC voltage VCC of about 3.3 V and in particular can also be integrated in the control circuit 30 itself.

The transistor driver circuit “MOSFET DRIVER” has four connections at its output (see 11 ), which are connected to the gate terminal of the MOSFET of the respective associated switch Q1, Q2, Q3 or Q4. In this specific example, the drain terminal of the first MOSFET (Q1) is connected to the source of the input DC voltage VF, its source terminal is connected to the drain terminal of the second MOSFET (Q2), whose source terminal is grounded. The first coil L1 is connected with its first terminal between the two MOSFETs of the switches Q1 and Q2, while the first capacitor C1 is connected between the second terminal of the first coil L1 and ground. The situation is similar in the second half-bridge 31b.

• In sogenannter „Phase eins“ der an den Elektroden 3a/3b anzulegenden Wechselspannung wird über die erste Halbbrücke 31a an der ersten Elektrode 3a der Sichtschutz-Folie 3 die Spannung der ersten Halbwelle der Wechselspannung abgebildet. Die zweite Elektrode 3b der Folie 3 ist dabei auf Masse geschaltet, indem der Schalter Q4 (auch Mosfet Low genannt) der zweiten Halbbrücke 31b dauerhaft durchgeschaltet ist. Dazu werden die Mosfets der Schalter Q1 und Q2 der ersten Halbbrücke 31a (die auch als Mosfet High (Q1) und Mosfet Low (Q2) bezeichnet werden) abwechselnd so geschaltet, dass zunächst Mosfet Low (Q2) vorrangig an ist. Im Scheitelpunkt des Maximalwertes der Halbwelle ist der High Mosfet (Q1) länger an. Es stellt sich dann der Maximalwert von 26 V an der Folie 3 ein (hieraus ergibt sich der oben genannte EffektivWert von etwa 18 V AC der an der Folie 3 angelegten Wechselspannung). Von diesem Zeitpunkt aus nimmt das Tastverhältnis des PWM-Ansteuerungssignals typischerweise wieder ab und Mosfet Low (Q2) schaltet länger. Im Punkt des Nulldurchganges der Wechselspannung beginnt die nachfolgend beschriebene „Phase zwei“:
  • Hier läuft es entsprechend „Phase eins“ ab, mit dem einzigen Unterschied, dass jetzt der Low Mosfet der ersten Halbbrücke 31a (Q2) dauerhaft durchgeschaltet ist und die Mosfets der zweiten Halbbrücke 3b (Mosfet High (Q3) und Mosfet Low (Q4)) abwechselnd geschaltet werden.
  • Die Sichtschutz-Folie 3 erhält als Ergebnis eine Spannungsschwingung von 26 V bis -26 V, und somit effektiv eine Wechselspannung von 18.43 V in diesem konkreten Beispiel.

Purely as an example, the following specific procedure of the control method presented here is possible:

• In the so-called “phase one” of the alternating voltage to be applied to the electrodes 3a/3b, the voltage of the first half-wave of the alternating voltage is mapped via the first half-bridge 31a to the first electrode 3a of the privacy film 3. The second electrode 3b of the film 3 is connected to ground by permanently switching on the switch Q4 (also called Mosfet Low) of the second half-bridge 31b. For this purpose, the Mosfets of the switches Q1 and Q2 of the first half-bridge 31a (which are also called Mosfet High (Q1) and Mosfet Low (Q2)) are switched alternately so that Mosfet Low (Q2) is primarily on. At the peak of the maximum value of the half-wave, the High Mosfet (Q1) is on for longer. The maximum value of 26 V is then set at foil 3 (this results in the above-mentioned effective value of about 18 V AC of the alternating voltage applied to foil 3). From this point on, the duty cycle of the PWM control signal typically decreases again and Mosfet Low (Q2) switches for a longer period. At the point where the alternating voltage crosses zero, the "phase two" described below begins:
  • Here it runs according to “phase one”, with the only difference that now the Low Mosfet of the first half-bridge 31a (Q2) is permanently switched on and the Mosfets of the second half-bridge 3b (Mosfet High (Q3) and Mosfet Low (Q4)) are switched alternately.
  • As a result, the privacy film 3 receives a voltage oscillation of 26 V to -26 V, and thus effectively an alternating voltage of 18.43 V in this specific example.

Numerous modifications and further developments of the described embodiments are possible.

Reference symbol

1

Mounting kit ( 1-10 )

2

Pet crate ( 1-10 )

3

Privacy film / PDLC

3a, 3b

Electrodes

3c

Edge side where the electrodes are located

3d

Edge sides adjacent to edge side 3c

4

Terminal block

4a, 4b

first and second terminal halves of a terminal block

4c

Film hinge that connects both clamp halves

4d

Removable protective strip on the self-adhesive back

4e

Fold line

5

Corner clamp bracket

5a

first angle clamp half

5b

second angle clamp half

5c

Angle cover part

5d

Supply line for connecting a control element

5e

Connector for connecting the control element

6

Control element

6a

power adapter

6b

Power plug

6c

Retaining plate

6d

double-sided self-adhesive strip

7a, 7b

both angle legs of a corner clamp

8th

connection cable

9

Connector for the connecting cable

10

Graph paper

10a

hinge side long side of the graph paper

10b

short sides of the graph paper

11

Mounting tape

12

Remote control unit

14

Control element

15a, 15b

Magnetic element

16

Window frame

16a

Frame corner

16b

Frame side

16c

window pane

16d

Inner edges of the frame sides

17

Hinge for opening the window

18, 20

both narrow sides of a cut terminal block in clamped state

19, 21

straight edges at the ends of the angle legs

22

straight marking line on each angle leg

23

Closure elements

24

Locking elements

25

electronic board

26

electrical spring contacts

27

Recess

28

windowsill

30

Control circuit

31a, 31b

Half bridges, here each designed as a step-down converter

32a, 32b

2nd order low-pass filter

L1, L2

first, second coil

C1, C2

first, second capacitor

Q1-Q4

first to fourth switch (Mosfet)

VF

(first/second) input DC voltage of both buck converters

VCC

(third) input DC voltage of the control element

A

Edge distance

D

Disc spacing

BUTTON

User input converter

RF-RX

User input recipient

µC

(Micro)controller

MOSFET DRIVERS

Transistor driver circuit

Claims (10)

Mounting kit (1) for attaching a switchable privacy film (3) to a window whose frame (16) has several corners (16a) and straight sides (16b) extending therebetween, comprising: a privacy film (3) which can be cut to the respective window size and which can be switched between a transparent state and a privacy protection state at least in a partial area of its surface and for this purpose comprises an electrically switchable layer between two electrically conductive layers, each of which is connected to an electrode (3a, 3b) for applying electrical voltage therebetween; one or more clamping strips (4) that can be cut to the respective lengths of the frame sides (16b), which are self-adhesive on the back and designed on the front for replaceable clamping of the privacy film (3); one corner clamping angle (5) for each frame corner (16a), which is self-adhesive on the back and designed on the front for replaceable clamping of the privacy film (3) and whose angle legs (7a, 7b) on both frame sides (16b) can be clearly positioned in the respective corner by mechanical stop or by alignment, wherein each corner clamping angle (5) has several straight edges (19, 21), marking lines (22) and/or projections for clear positioning of the clamping strips (4) to be placed thereon and the privacy film (3) to be clamped therein and at least two corner clamping angles (5) are designed for contacting the electrodes (3a, 3b); and an electronic control element (6) which is designed to be connected to the at least two corner clamping angles (5) and for the user to switch the privacy protection film (3) between its transparent and privacy protection state and for this purpose has a control circuit (30), wherein the control circuit (30) has two independently controllable half-bridges (31a, 31b), which can each be connected to one of the two electrodes (3a, 3b) of the privacy protection film (3) and are each designed as a step-down converter; so that by controlling both step-down converters, the privacy protection film (3) can be switched between its transparent and privacy protection state, wherein each electrode (3a, 3b) can be controlled independently of the other electrode (3b, 3a) via the associated step-down converter. Mounting kit (1) according to Claim 1 , characterized in that each corner clamping angle (5) and/or each clamping strip (4) has two clamping halves (5a, 5b; 4a, 4b) for interchangeably clamping the privacy film (3) between them; a first of the two clamping halves (5a, 4a) is designed to be self-adhesive on the back for fastening to a smooth surface such as a pane (16c) or a frame (16) of the window; the two clamping halves (5a, 5b; 4a, 4b) are designed separately from one another or are connected to one another via a hinge-like and/or flexible connection; and the two clamping halves (5a, 5b; 4a, 4b) can be releasably fixed to one another by a click or snap-in closure in the form of closure elements (23) designed in both clamping halves (5a, 5b; 4a, 4b) for engaging and snapping into one another and/or by a magnetic attraction force of magnetic elements (15a, 15b) designed to overlap one another in both clamping halves (5a, 5b; 4a, 4b), so that a predetermined clamping force is applied to the privacy film (3). Mounting kit (1) according to Claim 1 or 2 , characterized in that the at least two corner clamping angles (5) for contacting the electrodes (3a, 3b) each have electronic circuit boards (25) with plug connectors (9) and/or supply lines (5d) for connection to the electronic control element (6) and with electrical contacts (26) which are designed to bear with a contact pressure on the respective electrode (3a, 3b) after the aforementioned positioning and clamping of the privacy film (3) in the corner clamping angle (5). Mounting kit (1) according to one of the preceding claims, characterized in that in the control circuit (30) a first of the two step-down converters can be controlled to convert a predetermined first input direct voltage (VF) into a first output alternating voltage intended for a first electrode (3a) of the privacy film (3) and for this purpose has a first electrically controllable switch (Q1) and a second electrically controllable switch (Q2) which are connected in series between a source of the first input direct voltage (VF) and ground, and a first low-pass filter (32a) of the second order designed to smooth the first output alternating voltage, with a first coil (L1) and a first capacitor (C1); and/or the second step-down converter is controllable for converting a predetermined second input direct voltage (VF) into a second output alternating voltage intended for the second electrode (3b) of the privacy film (3) and for this purpose has a third electrically controllable switch (Q3) and a fourth electrically controllable switch (Q4) which are connected in series between a source of the second input direct voltage (VF) and ground, and a second low-pass filter (32b) of second order designed to smooth the second output alternating voltage, having a second coil (L2) and a second capacitor (C2). Mounting kit (1) according to one of the preceding claims, characterized in that in the control circuit (30) both down converters are designed substantially identically. Mounting kit (1) according to Claim 4 , characterized in that in the control circuit (30) the first coil (L1) has a predetermined inductance between about 50 µH and about 250 µH, preferably between about 100 µH and about 200 µH, particularly preferably between between about 125 µH and about 175 µH, in particular about 150 µH; and/or the second coil (L2) has a predetermined inductance between about 50 µH and about 250 µH, preferably between about 100 µH and about 200 µH, particularly preferably between about 125 µH and about 175 µH, in particular about 150 µH. Mounting kit (1) according to Claim 4 , characterized in that in the control circuit (30) the first capacitor (C1) has a predetermined capacitance between approximately 1 µF and approximately 20 µF, preferably between approximately 5 µF and approximately 15 µF, particularly preferably between approximately 7.5 µF and approximately 12.5 µF, in particular approximately 10 µF; and/or the second capacitor (C2) has a predetermined capacitance between approximately 1 µF and approximately 20 µF, preferably between approximately 5 µF and approximately 15 µF, particularly preferably between approximately 7.5 µF and approximately 12.5 µF, in particular approximately 10 µF. Mounting kit (1) according to Claim 4 , characterized in that in the control circuit (30) the first switch (Q1) has a first transistor, preferably MOSFET; and/or the second switch (Q2) has a second transistor, preferably MOSFET; and/or the third switch (Q3) has a third transistor, preferably MOSFET; and/or the fourth switch (Q4) has a fourth transistor, preferably MOSFET. Mounting kit (1) according to one of the preceding claims, characterized in that the control circuit (30) further comprises the following: a user input converter (BUTTON) which is designed to convert manual switching inputs of a user for the switchable film (3) into corresponding electrical input signals; and/or a user input receiver (RF RX) which is designed to receive and convert wirelessly transmitted switching inputs of a user for the switchable film (3) into corresponding electrical input signals; and/or a microcontroller (µC) which is designed at its input to receive electrical input signals which are based on manual and/or wirelessly transmitted switching inputs of a user, and at its output to output a corresponding digital control signal, in particular in the form of a PWM signal, for the two half-bridges (31a, 31b); and/or a transistor driver circuit (MOSFET DRIVER) which is designed at its input to receive a drive signal for the two half-bridges (31a, 31b) generated based on user-side switching inputs and is designed at its output to output corresponding gate drive voltages or currents for transistors contained in the two half-bridges (31a, 31b). Use of a mounting kit (1) according to one of the Claims 1 until 9 for the residue-free, removable and replaceable attachment of a switchable privacy film (3) to a window in private or business rooms such as a bedroom, a bathroom, a kitchen, an entrance area, a study or a meeting room.

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