DE202020101785U1 - Glazing arrangement - Google Patents

Abstract

Glazing arrangement of a vehicle or building, comprising
- A glazing unit with electrically controllable optical properties, which comprises an outer pane (1a) and an inner pane (1b), which are connected to one another via a thermoplastic intermediate layer (3), and in which a functional element (4) with electrically controllable optical properties is embedded comprising an active layer (5), to which transparent surface electrodes (8, 9) are assigned on both surfaces, and
- A control unit (11) for electrical control of the optical properties of the glazing unit, which is connected to the surface electrodes (8, 9) of the functional element (4) and is designed to apply an electrical voltage between the surface electrodes (8, 9), the Glazing unit or the control unit (11) has means for effectively short-circuiting the surface electrodes (8, 9) immediately when the voltage supply to the surface electrodes (8, 9) is switched off.

Description

The invention relates to a glazing arrangement of a vehicle or building, comprising a glazing unit with electrically controllable optical properties.

Electro-optical functional elements with electrically controllable optical properties have long been known in great diversity and are used in industrial mass production, for example in TV sets, laptops, cell phones / smartphones and tablets.

Glazing units with electrically controllable functional elements are also known as such. The optical properties of the functional elements can be changed by an applied electrical voltage. An example of such functional elements are SPD (suspended partide device) functional elements, which for example consist of EP 0876608 B1 and WO 2011033313 A1 are known. The applied voltage allows the transmission of visible light to be controlled by SPD functional elements. Another example are PDLC functional elements (polymer dispersed liquid crystal), which for example consist of DE 102008026339 A1 are known. The active layer contains liquid crystals which are embedded in a polymer matrix. If no voltage is applied, the liquid crystals are disordered, which leads to a strong scattering of the light passing through the active layer. If a voltage is applied to the surface electrodes, the liquid crystals align in a common direction and the transmission of light through the active layer is increased.

Windshields have been proposed in which an electrically controllable sun visor is implemented by such a functional element in order to replace the conventional mechanically foldable sun visor in motor vehicles. Windshields with electrically controllable sun visors are known, for example, from DE 102013001334 A1 , DE 102005049081 B3 , DE 102005007427 A1 and DE 102007027296 A1 .

SPD and PDLC functional elements are commercially available as multilayer foils, the active layer and the surface electrodes required for applying a voltage being arranged between two carrier foils, typically made of PET. During the manufacture of the glazing unit, the functional element is cut out of the multilayer film in the desired size and shape and inserted between the films of an intermediate layer, by means of which two glass panes are laminated together to form the glazing unit.

It goes without saying that glazing units which contain electro-optical functional elements to increase comfort and which are used in vehicles are subject to the same safety requirements as conventional vehicle windows. In an accident in which the glazing unit and / or the connection to the control unit in the vehicle is interrupted, or an interruption in the voltage supply to the glazing unit, there should be no danger to the occupants. In particular, the optical properties that the glazing unit has when the electro-optical functional element is switched off are to be developed as quickly as possible after the switch-off.

This object is achieved by a glazing arrangement with the features of claim 1. Appropriate developments of the inventive concept are the subject of the dependent claims.

It is an idea of the invention to accelerate the development of the optical properties of the switched-off state of the electro-optical functional element, which typically takes several seconds, by an additional measure. The invention also includes the idea of causing this acceleration by promoting the charge equalization between the surface electrodes of the functional element. Finally, the idea of the invention is to achieve this promotion of charge balance by establishing or activating a low-resistance connection between the surface electrodes.

With the invention, an accelerated optical response of a glazing unit of the generic type and thereby a noticeable increase in the use value for the user can be achieved without significant additional effort. Of course, this indirectly contributes to an increase in the market prospects for corresponding glazing arrangements.

The glazing arrangement of a vehicle or building according to the invention comprises a glazing unit with electrically controllable optical properties, which comprises an outer pane and an inner pane, which are connected to one another via a thermoplastic intermediate layer, and in which a functional element with electrically controllable optical properties is embedded, comprising an active one Layer to which transparent surface electrodes are assigned on both surfaces. In the sense of the invention, the functional element is also referred to as an optoelectronic functional element. The glazing arrangement also includes a control unit for electrical Control of the optical properties of the glazing unit. The control unit is connected to the surface electrodes of the functional element and is designed to apply an electrical voltage between the surface electrodes. According to the invention, the glazing unit or the control unit has means for effectively short-circuiting the surface electrodes directly when the voltage supply to the surface electrodes is switched off.

The glazing unit comprises at least one outer pane and one inner pane, which are connected to one another via an intermediate layer. The glazing unit is intended to separate the interior from the external environment in a window opening, for example of a vehicle, a building or a room. For the purposes of the invention, the inner pane is the inner pane. The outer pane is the pane facing the external environment. The thermoplastic intermediate layer serves to connect the two panes, as is common with glazing units.

The outer pane and the inner pane are preferably made of glass. In principle, however, they can also consist of plastic. The thickness of the outer pane and the inner pane can vary widely and can thus be adapted to individual requirements. The outer pane and the inner pane preferably have thicknesses of 0.5 mm to 5 mm, particularly preferably from 1 mm to 3 mm. The lenses can be clear, or they can be tinted or colored. A corresponding windshield must have sufficient light transmission in the central viewing area, preferably at least 70% in the main viewing area A according to ECE-R43.

The outer pane, the inner pane and / or the intermediate layer can have further suitable coatings known per se, for example anti-reflective coatings, non-stick coatings, anti-scratch coatings, photocatalytic coatings or sun protection coatings or low-E coatings).

The glazing unit contains an electro-optical functional element with electrically controllable optical properties, which is embedded in the intermediate layer. The functional element is typically arranged between at least two layers of thermoplastic material of the intermediate layer, it being connected to the outer pane by the first layer and to the inner pane by the second layer.

The functional element comprises at least one active layer, which is arranged between a first carrier film and a second carrier film. The active layer has the variable optical properties that can be controlled by an electrical voltage applied to the active layer. For the purposes of the invention, electrically controllable optical properties are understood to mean those properties which can be steplessly controlled, but equally also those which can be switched between two or more discrete states. The said optical properties relate in particular to the light transmission and / or the scattering behavior. The functional element also comprises surface electrodes for applying the voltage to the active layer, which are preferably arranged between the carrier films and the active layer.

In a preferred embodiment, the functional element is a PDLC functional element, in particular one that switches at least one area of the glazing unit from a transparent to an opaque state and vice versa. The active layer of a PDLC functional element contains liquid crystals which are embedded in a polymer matrix. In a further preferred embodiment, the functional element is an SPD functional element. The active layer contains suspended particles, the absorption of light by the active layer being changeable by applying a voltage to the surface electrodes. In principle, however, it is also possible to use the invention in other types of controllable functional elements, for example in electrochromic functional elements. The controllable functional elements mentioned and their mode of operation are known per se to the person skilled in the art, so that a detailed description can be dispensed with here.

The surface electrodes and the active layer are typically arranged essentially parallel to the surfaces of the outer pane and the inner pane. The surface electrodes are electrically connected to an external voltage source in a manner known per se. The electrical contacting, as well as the connection to the energy source for temperature control of the active layer, is implemented by means of suitable connecting cables, for example foil conductors, which optionally have so-called bus bars, for example strips of an electrically conductive material or electrically conductive imprints, with the surface electrodes are connected. The thickness of the functional element is, for example, from 0.4 mm to 1 mm.

The surface electrodes are preferably designed as transparent, electrically conductive layers. The surface electrodes preferably contain at least one metal, a metal alloy or a transparent conductive oxide (TCO). The surface electrodes can, for example, be silver, gold, copper, nickel, chromium, Contain tungsten, indium-tin oxide (ITO), gallium-doped or aluminum-doped zinc oxide and / or fluorine-doped or antimony-doped tin oxide. The surface electrodes preferably have a thickness of 10 nm to 2 μm, particularly preferably from 20 nm to 1 μm, very particularly preferably from 30 nm to 500 nm.

The functional element is in particular in the form of a prefabricated multilayer film with two outer carrier films. With such a multilayer film, the surface electrodes and the active layer are typically arranged between the two carrier films. By outer carrier film is meant here that the carrier films form the two surfaces of the multilayer film. The functional element can thereby be provided as a laminated film, which can be processed advantageously. The functional element is advantageously protected from damage, in particular corrosion, by the carrier films. In commercially available versions, the thickness of the polymer film or the film laminate and the electronic functional unit and the battery is less than 1.2 mm, in particular in the range between 0.5 mm and 1.0 mm.

As already noted, the invention is particularly advantageous in the case of the windscreen or rear window or roof glazing of a vehicle, in particular a passenger car, the electronic functional unit being inserted as a completely prefabricated functional module in a cutout in the polymer film or the film laminate. In a particularly advantageous embodiment, the glazing unit is the windshield of a motor vehicle, in particular a passenger car, with an electrically controllable sun visor, which is implemented by the functional element.

The windshield has an upper edge and a lower edge and two side edges running between the upper edge and the lower edge. The top edge is the edge which is intended to point upwards in the installed position. The lower edge is the edge that is intended to point downwards in the installed position. The top edge is often referred to as the roof edge and the bottom edge as the engine edge. The edges of the functional element are designated according to the installation position of the windshield. The lower edge of the functional element is therefore that of its side edges which faces away from the upper edge of the windshield and points towards the central field of vision. The top edge of the functional element faces the top edge of the windshield. The side edges run between the top edge and the bottom edge.

Windshields have a central field of vision, the optical quality of which places high demands. The central field of vision must have high light transmission (typically greater than 70%). Said central field of vision is in particular that field of vision that the specialist has as a field of vision B , Field of view B or zone B referred to as. The field of vision B and its technical requirements are set out in Regulation No. 43 of the United Nations Economic Commission for Europe (UN / ECE) (ECE-R43, "Uniform Conditions for the Approval of Safety Glazing Materials and their Installation in Vehicles"). There is the field of vision B attached 18th Are defined.

The functional element is above the central field of view (field of view B ) arranged. This means that the functional element is arranged in the area between the central field of vision and the upper edge of the windshield. The functional element does not have to cover the entire area, but is positioned entirely within this area and does not protrude into the central field of vision. In other words, the functional element has a smaller distance from the upper edge of the windshield than the central field of vision. Thus, the transmission of the central field of view is not affected by the functional element, which is positioned at a similar location to a classic mechanical sun visor when folded down.

In a preferred embodiment, the lower edges of the functional element and the tinted area of the thermoplastic layer are adapted to the shape of the upper edge of the windshield, which results in a more visually appealing appearance. Since the upper edge of a windshield is typically curved, in particular concavely curved, the lower edge of the functional element and of the tinted area is also preferably curved. The lower edges of the functional element are particularly preferably formed essentially parallel to the upper edge of the windshield. But it is also possible to construct the sun visor from two straight halves, which are arranged at an angle to each other and approximate the shape of the upper edge in a V-shape.

The top edge and the side edges of the functional element are preferably covered by an opaque cover print when looking through the windshield. Windshields typically have an all-round peripheral masking print made of an opaque enamel, which is used in particular to protect and visually mask the adhesive used to install the windshield from UV radiation. This peripheral Masking pressure is preferably used to cover the top edge and the side edge of the functional element as well as the required electrical connections. The sun visor is then advantageously integrated into the appearance of the windshield and only the lower edge is potentially recognizable to the viewer. Both the outer pane and the inner pane preferably have a covering pressure, so that the view from both sides is prevented.

In a first embodiment of the invention, the means for effectively short-circuiting the surface electrodes have a short-circuit switch for reducing the internal resistance of the control unit. In principle, the effect according to the invention is therefore realized within the control unit or at its output.

In an alternative embodiment it is provided that the means for effectively short-circuiting the surface electrodes have a switchable short-circuit bridge between the surface electrodes. In this variant, the function according to the invention is in principle carried out within the glazing unit or at its entrance.

In both versions, the short-circuit switch or the relevant switching element can be realized by an electronic switch known for such purposes, in particular a FET or thyristor switch.

In a further embodiment, in the operating state of the glazing arrangement, one surface electrode of the glazing unit is connected to ground potential, while the other surface electrode is at a control voltage supplied by the control unit, the other surface electrode being assigned a switching element which is activated by the control unit when the power supply is switched off and which connects another surface electrode to ground. Here too, in order to implement the switchover of one of the two surface electrodes to ground potential, a switching element is basically required which responds quickly to the switch-off control signal of the arrangement and can be implemented by an electronic switch with the corresponding switching characteristic.

• 1 eine Draufsicht auf eine erste Ausgestaltung der erfindungsgemäßen Verbundscheibe als Windschutzscheibe mit elektrisch steuerbarer Sonnenblende,
• 2 einen Querschnitt durch die Windschutzscheibe aus 1,
• 3 eine vergrößerte Darstellung des Bereichs Z aus 2,
• 4A und 4B eine Prinzipskizze zur Wirkungsweise der Ausführung der Erfindung.

The invention is explained in more detail with reference to figures and exemplary embodiments. The drawing is a schematic representation and not to scale. The figures in no way limit the invention.
Show it:

• 1 2 shows a top view of a first embodiment of the composite pane according to the invention as a windshield with an electrically controllable sun visor,
• 2nd a cross section through the windshield 1 ,
• 3rd an enlarged view of the area Z from 2nd ,
• 4A and 4B a schematic diagram of the operation of the implementation of the invention.

1 to 3rd each show a detail of a windshield 1 with electrically controllable sun visor S as a preferred composite pane with electrically controllable optical properties. The windshield 1 includes an outer pane 1a and an inner pane 1b that have an intermediate layer 3rd are interconnected. The outer pane 1a has a thickness of 2.1 mm and consists of a green colored soda-lime glass. The inner pane 1b has a thickness of 1.6 mm and is made of clear soda-lime glass. The windshield 1 has an upper edge facing the roof when installed D and a lower edge facing the engine compartment in the installed position M .

The windshield is in an area above the central viewing area B (as defined in ECE-R43) with an electrically controllable sun visor S fitted. The sun visor S is by a commercially available PDLC multilayer film as a functional element 4th formed that in the intermediate layer 3rd is stored. For example, the height of the sun visor is 21 cm.

The intermediate layer 3rd comprises a total of three thermoplastic layers 3a , 3b , 3c , which are each formed by a thermoplastic film with a thickness of 0.38 mm from PVB. The first thermoplastic layer 3a is with the outer pane 1 connected, the second thermoplastic layer 3b with the inner pane 2nd . The third thermoplastic layer in between 3c has a cutout in which the cut PDLC multilayer film is inserted essentially precisely, that is to say approximately flush on all sides. The third thermoplastic layer 3c forms a kind of passe-partout for the approximately 0.4 mm thick functional element 4th , which is encapsulated in thermoplastic material all around and thus protected.

The first thermoplastic layer 3a has a tinted area 3a ' on that between the functional element 4th and the outer pane 1 is arranged. The light transmission of the windshield is thereby in the area of the sun visor 4th additionally reduced and the milky appearance of the PDLC functional element 4th softened in the diffuse state. This makes the aesthetics of the windshield much more appealing. The first thermoplastic layer 3a points in the area 3a ' for example an average Light transmission from 30%, which gives good results. The area 3a ' can be tinted homogeneously. However, it is often more visually appealing if the tint is in the direction of the lower edge of the functional element 4th becomes smaller, so that the tinted and the untoned area flow into one another. In the case shown, the bottom edges of the tinted area 3a ' and the PDLC functional element 4th arranged flush. However, this is not necessarily the case. It is also possible that the tinted area 3a ' via the functional element 4th survives or that conversely the functional element 4th over the tinted area 3a ' survives.

The controllable functional element 4th is a multilayer film consisting of an active layer 5 between two surface electrodes 8th , 9 and two carrier foils 6 , 7 . The active layer 5 contains a polymer matrix with liquid crystals dispersed in it, which align themselves depending on the electrical voltage applied to the surface electrodes, as a result of which the optical properties can be regulated. The carrier films 6 , 7 consist of PET and have a thickness of approx. 0.2 mm, for example. The carrier films 6 , 7 are with one to the active layer 5 facing coating made of ITO with a thickness of about 100 nm, which the surface electrodes 8th , 9 form. The surface electrodes 8th , 9 can be connected to the on-board electrical system via busbars, not shown (for example formed by a silver-containing screen print) and connecting cables, not shown.

As usual, the windshield has a peripheral peripheral covering pressure 10th on the outer pane thanks to an opaque enamel on the interior surfaces (facing the interior of the vehicle when installed) 1 and the inner pane 2nd is trained. The distance of the functional element 4th to the top edge D and the side edges of the windshield is less than the width of the masking pressure 10th so that the side edges of the functional element 4th - with the exception of the central field of vision B facing side edge - through the cover print 10th are covered. The electrical connections, not shown, also make sense in the area of the masking pressure 10th attached and thus hidden.

4A and 4B represent, as schematic diagrams in the manner of cross-sectional representations, the switched-on state of a glazing arrangement with a PDLC functional element ( 4A) and the switch-off state designed according to the invention ( 4B) towards each other. A control unit 11 of the functional element 4th (the sun visor S ) is symbolized here by a voltage source "V", and the on or off status of the functional element 4th is by a closed or open switch 12 symbolizes.

It can be seen that in the switched-off state, specifically according to the invention immediately (immediately) after opening the switch S between the functional element 4th and the control unit 11 a "short circuit bridge" (to be interpreted functionally here) 13 between the two surface electrodes 8th , 9 of the functional element is created, via which a practically immediate charge equalization takes place between the surface electrodes. This in turn causes the optical state to be established immediately, which the functional element assumes when it is switched off (but typically only after several seconds). For the realization of the short circuit bridge 13 there are various options.

Reference symbol list

1

Windshield

1a

Outer pane

1b

Inner pane

3rd

thermoplastic intermediate layer

3a

first layer of the intermediate layer 3rd

3a '

tinted area of the first layer 3a

3b

second layer of the intermediate layer 3rd

3c

third layer of the intermediate layer 3rd

4th

Functional element with electrically controllable optical properties

5

active layer of the functional element 4th

6

first carrier film of the functional element 4th

7

second carrier film of the functional element 4th

8, 9

Surface electrode of the functional element 4th

10th

Masking pressure

11

Control unit

12

Switch between control unit and electro-optical functional element

13

Short circuit bridge

A

Main viewing area

B

Field of view

C.

electronic functional unit

D

Top edge

M

Lower edge

S

Controllable sun visor

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 0876608 B1 [0003]
• WO 2011033313 A1 [0003]
• DE 102008026339 A1 [0003]
• DE 102013001334 A1 [0004]
• DE 102005049081 B3 [0004]
• DE 102005007427 A1 [0004]
• DE 102007027296 A1 [0004]

Claims (8)

Glazing arrangement of a vehicle or building, comprising - A glazing unit with electrically controllable optical properties, which comprises an outer pane (1a) and an inner pane (1b), which are connected to one another via a thermoplastic intermediate layer (3), and in which a functional element (4) with electrically controllable optical properties is embedded comprising an active layer (5), to which transparent surface electrodes (8, 9) are assigned on both surfaces, and - A control unit (11) for electrical control of the optical properties of the glazing unit, which is connected to the surface electrodes (8, 9) of the functional element (4) and is designed to apply an electrical voltage between the surface electrodes (8, 9), the Glazing unit or the control unit (11) has means for effectively short-circuiting the surface electrodes (8, 9) immediately when the voltage supply to the surface electrodes (8, 9) is switched off. Glazing arrangement after Claim 1 The means for effectively short-circuiting the surface electrodes (8, 9) have a short-circuit switch for reducing the internal resistance of the control unit. Glazing arrangement after Claim 2 , wherein the short-circuit switch has a FET or thyristor switch. Glazing arrangement after Claim 1 The means for effectively short-circuiting the surface electrodes have a switchable short-circuit bridge (13) between the surface electrodes (8, 9). Glazing arrangement after Claim 4 , wherein the short-circuit bridge (13) has an FET or thyristor switching element. Glazing arrangement according to one of the Claims 1 to 5 , In the operating state of the glazing arrangement, one surface electrode (8) of the glazing unit is connected to ground potential, while the other surface electrode (9) is at a control voltage supplied by the control unit (11), the other surface electrode (9) being switched on when the power supply is switched off is assigned by the control unit (11) activated switching element which connects the other surface electrode (9) to ground. Glazing arrangement according to one of the Claims 1 to 6 , wherein the functional element (4) is a PDLC functional element which makes the glazing unit appear transparent at least in some areas when the power supply is switched on and opaque when the power supply is switched off. Vehicle, in particular car, with a glazing arrangement according to one of the Claims 1 to 7 .

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