DE102019130022A1 - Method for integrating a hologram in a composite pane with curved geometry, in particular in a vehicle pane, a resulting composite pane and a vehicle containing it - Google Patents

Abstract

The invention relates to a method for integrating a hologram, in particular a holographic optical element, in a pane composite of a predetermined curved geometry, in particular in a vehicle pane, with the following steps: providing a partial composite comprising several panes already laminated to one another, or a single pane, who already has the predetermined curved geometry; - providing a substrate wafer with a hologram recording layer applied to it or embedded therein, in particular made of liquid photopolymer, in which the hologram is then produced by a suitable exposure process; and- connecting the substrate wafer thus equipped with the hologram to the individual wafer or the partial composite by means of a connecting layer to form a wafer composite having the predetermined curved geometry by a lamination process that is gentle on the hologram and in which the temperature does not reach a predetermined maximum temperature and / or the pressure does not reach a predetermined maximum pressure - The hologram in the composite disk remains protected from the outside by the substrate disk, in that it is arranged between the substrate disk and the individual disk or the partial composite or is embedded in the substrate disk.

Description

Technical area

The invention relates to a method for integrating a hologram in a composite pane of a predetermined curved geometry, in particular in a vehicle pane, as well as a resulting composite pane with a hologram and a vehicle equipped therewith. The vehicle can be any land, air or water vehicle, in particular a motor vehicle. The hologram can, in particular, be a holographic optical element (HOE) that is intended to be integrated, for example, as an element of a field of view display device in a windshield of the vehicle.

Technical background

Field of view display devices in a vehicle are known in particular under the designation head-up display (HUD). In this way, display content, for example information about a speed limit or other navigation and vehicle operating instructions, is superimposed in the form of a virtual display image on the real image of the surroundings in front of the vehicle observed by the driver. For this purpose, a field of view display device usually comprises a projection unit built into the instrument panel, which generates a projection light beam with the desired display content and projects it onto the windshield of the vehicle, from which it is reflected towards the driver.

In order to largely spare the driver from having to adjust his eyes when changing his gaze between the road ahead and the display to be read, the virtual display image is typically generated some distance in front of the vehicle. In order to achieve these and other imaging properties, projection units in head-up displays for the automotive sector are classically constructed using concave mirrors, but their size is linear with the image size of the virtual display image and a field of view that can be covered with it (also called field-of-view, FoV ) scaled. In order to significantly expand the field-of-view that can be covered, for example for a contact-analog AR display (Augmented Reality) oriented towards real surrounding objects, a correspondingly large concave mirror would have to be integrated in the instrument panel with the classic HUD design, which creates problems for the available one Installation space in the vehicle interior or also for its appearance, since in turn a correspondingly large opening for the exiting projection light beam would be required in the instrument panel.

To overcome such problems, approaches are known for field of view display devices in motor vehicles to integrate a holographic optical element (HOE) into the windshield of a vehicle, which, for example, takes on the optical function of a concave mirror customary for the classic projection unit. This enables a more compact HUD design without a concave mirror, which is also known as a holographic head-up display. For example, it is off U.S. 4,998,784 A known to produce a hologram first as a flat film with the required optical properties on a separate flexible substrate and then to laminate it between two panes of a VSG (laminated safety glass) structure typical for vehicle windows using a hot melt adhesive PVB (polyvinyl butyral) connecting them. The flexible substrate on which the hologram was originally produced is peeled off or chemically dissolved from the hologram before the final lamination process and is therefore not contained in the resulting vehicle window.

When laminating such finished HOE films in a pane composite, however, they are exposed to high pressures of up to 12-15 bar and temperatures of up to 130-140 ° C, which can have a negative effect on the material properties and the durability of the hologram. Furthermore, the lamination of a hologram produced as a flat film or flat foil into a 3D curved geometry of a vehicle window is generally not possible without creasing or folding the HOE foil. However, this considerably impairs the optical function of the hologram, which is usually generated before lamination, usually in a roll-to-roll process. Different coefficients of thermal expansion of the glass panes on the one hand and an HOE film to be laminated in between under such high temperatures and pressures on the other hand also contribute to the problems mentioned. All these problems tend to become all the more serious with the enlargement of the surface of the hologram in the disk, which is necessary for AR applications.

All attempts to laminate a hologram-receptive material, for example in the form of a holographic film, into laminated glass before exposure and only then to expose a hologram or HOE there, require massive interventions in the laminated glass manufacturing process and are due to the requirements of the exposure process such as temperature stability, freedom from vibrations, dark surroundings, etc., can hardly be implemented industrially.

On the other hand, a hologram production method through the production of so-called " Contact Copies ”is known to be particularly useful for mass production. A hologram recording layer made of a photopolymer is applied in liquid form to a substrate, for example a film or foil, and exposed in reflection in direct contact with a master hologram (also called a holographic master) and thereby copied, ie replicated. In other words, a holographic master, which is usually a surface hologram, is used for the repeated production of a hologram, which is usually formed as a volume hologram in the photopolymer layer. The liquid photopolymer only hardens during exposure and subsequent fixation with UV light.

With this method, the layer thickness of the liquid photopolymer can be set with an accuracy of less than 10 micrometers. In this context, geometrical tolerances between the substrate and the holographic master play a major role, because on the one hand the master has to be in full contact with the photopolymer for the duration of the hologram recording and on the other hand the distance between the master and the substrate, the mentioned layer thickness of the photopolymer layer certainly. In the case of a flat, i.e. H. flat geometry, the constant distances required for hologram recording between a flat substrate and a flat holographic master can easily be set precisely, for example in a roll-to-roll process. In known methods, the substrate is typically provided as a flat film or sheet, i.e., a flat sheet. H. not bent, formed, while the holographic master is usually a metallic, rigid component that is not flexible and therefore cannot compensate for substrate tolerances.

An integration of a holographic optical element in / on a vehicle window designed as ESG (toughened safety glass) has not been possible up to now, since a liquid photopolymer is not applied to a three-dimensionally curved ESG window or a holographic master does not have the required contact surface, etc. can be held and a separately produced HOE film cannot simply be glued to an ESG pane, since, among other things, the required durability of the hologram against aging is not given in this way.

It is the object of the present invention to provide an alternative or improved method for integrating a hologram, in particular a holographic optical element, in a pane composite with three-dimensionally curved geometry, in particular in a vehicle pane, in order to solve the above problems. It is also an object of the invention to specify a corresponding composite pane and a vehicle equipped therewith.

Disclosure of the invention

This object is achieved by a method for integrating a hologram in a composite pane of a predetermined curved geometry according to independent claims 1 and 8 and by a resulting composite pane, in particular a vehicle pane, and a vehicle equipped therewith according to the independent claims. Further refinements are given in the dependent claims. All of the additional features and effects mentioned in the claims and the description for the method also apply in relation to the pane composite with a hologram integrated therein and the vehicle, and vice versa.

The order in which the individual process steps are described is to be understood as non-binding, unless otherwise stated. Rather, individual steps of the method set out herein can, if suitable, each be carried out in a different order than described in order to arrive at the same result mentioned.

According to a first aspect, a method for integrating a hologram in a composite pane with a predetermined curved geometry is provided. The window composite resulting therefrom can in particular be designed as a vehicle window, for example a front window, and therefore its flat window, ie. H. planar geometry deviating three-dimensionally curved geometric shape (predetermined curved geometry) have.

The hologram can, in particular, be a holographic optical element (HOE) that is to be integrated into a windshield of the vehicle, for example as an element of a field of view display device of the type described above, in particular a head-up display (HUD), for example To take over the function of a concave mirror. Alternatively, the present method can also be used to implement other optical functions of the HOE integrated in the curved pane assembly, for example an angle-selective diffuser hologram for displaying display content directly on the resulting (vehicle) pane, which can thus serve as a kind of screen, or a coupling -Hologram for a waveguide HUD, in which a flat waveguide is designed in the front pane to display content. The vehicle can be any land, air or water vehicle, in particular a motor vehicle.

• - Bereitstellen eines Teilverbunds, der mehrere miteinander bereits laminierte Scheiben umfasst und beispielsweise eine fertige herkömmliche VSG-Scheibe (Verbund-Sicherheitsglas) aus zwei durch eine reißfeste und zähelastische PVB-Folie (Polyvinylbutyral) verbundenen Glasscheiben ist. Alternativ kann eine Einzelscheibe, beispielsweise eine fertige herkömmliche ESG-Scheibe (Einscheiben-Sicherheitsglas), bereitgestellt werden. Dieser Teilverbund bzw. diese Einzelscheibe besitzt bereits die vorbestimmte gebogene Geometrie, die auch der künftige Scheibenverbund beibehalten soll, und kann insbesondere bei den nachfolgend beschriebenen Durchführungsbedingungen des vorliegenden Verfahrens (schonender Laminationsprozess) starr sein;
• - Bereitstellen einer Substratscheibe mit einer darauf aufgetragenen oder aufgebrachten oder darin eingebetteten Hologrammaufnahmeschicht, insbesondere aus flüssigem Fotopolymer, in der anschließend das Hologramm durch einen geeigneten Belichtungsprozess mit einem kohärenten Licht erzeugt wird; und
• - Verbinden der auf diese Weise mit dem Hologramm ausgestatteten Substratscheibe mit der Einzelscheibe oder dem Teilverbund mittels einer Verbindungschicht, insbesondere aus PVB oder einem anderen Schmelzklebstoff mit einer geeigneten niedrigen Aktivierungstemperatur, zu einem die vorbestimmte gebogene Geometrie aufweisenden Scheibenverbund durch einen das Hologramm schonenden Laminationsprozess, bei dem die Temperatur eine vorbestimmte Höchsttemperatur und/oder der Druck einen vorbestimmten Höchstdruck nicht überschreiten;
• - wobei das Hologramm im fertigen Scheibenverbund durch die Substratscheibe nach außen geschützt bleibt, indem es zwischen der Substratscheibe und der Einzelscheibe bzw. dem Teilverbund angeordnet oder in der Substratscheibe eingebettet ist.

The process comprises the following steps:

• Provision of a partial composite which comprises several panes already laminated to one another and is, for example, a finished conventional VSG pane (laminated safety glass) made of two panes of glass connected by a tear-resistant and viscoplastic PVB film (polyvinyl butyral). Alternatively, a single pane, for example a finished conventional ESG pane (toughened safety glass), can be provided. This partial composite or this individual pane already has the predetermined curved geometry, which the future pane composite is also intended to maintain, and can be rigid in particular in the case of the implementation conditions of the present method described below (gentle lamination process);
• Provision of a substrate wafer with a hologram receiving layer applied or applied to it or embedded therein, in particular made of liquid photopolymer, in which the hologram is then generated by a suitable exposure process with a coherent light; and
• - Connecting the substrate wafer equipped with the hologram in this way to the individual wafer or the partial composite by means of a connecting layer, in particular made of PVB or another hotmelt adhesive with a suitable low activation temperature, to form a laminated wafer having the predetermined curved geometry by a lamination process that is gentle on the hologram that the temperature does not exceed a predetermined maximum temperature and / or the pressure does not exceed a predetermined maximum pressure;
• - The hologram in the finished composite disk remains protected from the outside by the substrate disk, in that it is arranged between the substrate disk and the individual disk or the partial composite or is embedded in the substrate disk.

One idea of the present method is to separate the integration of a hologram or an HOE, for example on the basis of a liquid photopolymer, from the conventional lamination process of a laminated safety glass vehicle glazing mentioned at the beginning. B. at lower temperatures and / or pressures to replace. This can either be integrated directly into the production process of a vehicle window or completely outsourced, for example as an upgrade or retrofit. With this laminated pane structure and process, any vehicle glazing can in principle be equipped with a hologram over a large or full area without interfering with the standard manufacturing process. However, this method can also be used to equip individual sub-areas of vehicle glazing with a hologram. (The application is not limited to a vehicle window.) Furthermore, a hologram / HOE can also be applied to an ESG window using this method.

The substrate pane on / in which the hologram has been exposed is an integral part of the resulting pane composite, in particular the vehicle pane. A resistance of the hologram to aging that is required for a specific application can be ensured by a suitable choice of the material and / or the thickness of the substrate wafer. Furthermore, the substrate pane can in particular be made of a material suitable for exposing the hologram through the substrate pane and / or for optical properties of the resulting pane composite such as general transparency, for example made of plastic, for example polycarbonate or the like, or glass, for example soda-lime, Borosilicate or aluminum silicate glass or similar. Their thickness can, for example, be in the range of wall thicknesses of individual glass panes generally used for vehicle glazing of about 1.5-2 mm, or also thinner or thicker, depending on the specific application and depending on the choice of one of the many different embodiments and variants of the present method, which are described below.

In particular, the substrate wafer protects the hologram generated directly on it from mechanical damage or uncontrolled deformation such as creasing or wrinkling, even during the gentle lamination to the wafer composite, since it supports it over the entire surface and since the hologram recording layer usually already forms a stable material composite with the substrate wafer during the hologram production . In the case of a hologram receiving layer embedded in the substrate wafer, the material of the substrate wafer surrounds and supports the hologram produced therein from all sides.

According to a first embodiment, the substrate wafer is provided as a flat, ie flat plastic or thin glass wafer, which is deformed together with the hologram previously generated thereon or in it by connection to the individual wafer or the partial composite in a gentle lamination process to its predetermined curved geometry. In particular when applying liquid photopolymer, it can be particularly useful for the photopolymer to be applied to a flat substrate disk and is exposed, for example, in contact with a holographic master of the type described below, since in the case of a flat substrate geometry, no tolerance compensation is necessary during the hologram production, as in the case of a tolerance-afflicted curved geometry. (Examples of a tolerance compensation possible, especially with curved geometry, are given below.) For example, a flat thin glass pane is coated with the photopolymer, exposed with the hologram and then with an additional adhesive, e.g. B. PVB, applied to conventional vehicle glazing.

A flat thin glass pane can for example be made of soda-lime, borosilicate or aluminum silicate glass or the like and has a significantly smaller wall thickness compared to the glass panes generally used in vehicle glazing, whose wall thicknesses are typically in the range of 1.6 mm or 1.8 mm and their handling is therefore extremely complex with flat and especially with curved geometry - especially during the exposure process - to avoid glass breakage. In the present embodiment, the flat thin glass pane can, for example, have a wall thickness of less than 1 mm, 0.75 mm, 0.5 mm, 0.25 mm, 0.1 mm, 0.075 mm, 0.05 mm or as 0.03 mm or even in the range of about 0.025 mm, in particular increasingly preferred in the order given. The thin glass used can, for example, be chemically hardened in a manner known per se and therefore be significantly less fragile than a thick pane of glass.

Due to a suitable pretreatment of this type and the low wall thickness, a flat thin glass pane can be deformed against the predetermined curved geometry of the partial composite or the individual pane without any problems and without damage or glass breakage by the gentle lamination process of the type set out here. In contrast to thick glass panes of the above-mentioned wall thickness, whose bending process to create the curved 3D geometry of a vehicle window can require extremely high temperatures of up to 650 ° C, the flat thin glass used here as a substrate pane can already be converted at temperatures below 140 ° C deform said curved geometry. The same can be achieved with a flat substrate disk made of plastic, for example by a suitable choice of plastic, in particular with a correspondingly low glass transition temperature and / or the wall thickness.

According to a second embodiment alternative to this, not only the partial composite or the individual wafer, but also the substrate wafer to be equipped with the hologram, is provided from the outset with the predetermined curved geometry and also has this after the hologram has been generated, ie. H. together with the hologram receiving layer with the hologram produced therein. This enables the subsequent hologram production directly on or in a substrate wafer bent according to the desired 3D geometry of the wafer composite, so that the hologram is produced in the final geometry of the wafer composite and does not have to be subsequently deformed during the lamination process. For example, in this embodiment, the liquid photopolymer can be applied to the 3D-curved substrate disk made of plastic or glass, which z. B. has the geometry of the windshield, applied and exposed and then with an additional adhesive, for. B. PVB, can be applied to conventional laminated safety glass or ESG vehicle glazing. (Examples of a tolerance compensation that is possible, particularly when using a holographic master, between the master and a curved substrate wafer subject to tolerances are given below.)

In particular, in the present method, the substrate disc can be made of plastic and the hologram recording layer can be embedded in it by the hologram recording material, for example solid or liquid photopolymer, being dissolved and / or embedded in the plastic matrix or as an inner layer consisting of the hologram recording material in a multi-stage manufacturing process the substrate wafer and is / is in particular surrounded on all sides by plastic. The production of such a substrate wafer can, but does not have to be, part of the present method. The hologram recording material embedded in the plastic matrix can in particular - similar to a fiber composite material - be a so-called particle composite material made of hologram recording material and the underlying plastic matrix.

In the present method, the hologram can be generated in all its variants and configurations, in particular by making a so-called "contact copy" of a holographic master, which is usually a surface hologram and can be used for the repeated production of a hologram, which as a rule is a volume hologram in the hologram receiving layer is formed. For this purpose, for example, a hologram recording layer made of a photopolymer is applied in liquid form to the substrate wafer and exposed in direct contact with the holographic master, for example through the substrate wafer in reflection, and thereby copied, d. H. replicated.

In addition to its function as a hologram negative, the holographic master held against the hologram receiving layer can also contribute to ensuring the required freedom from vibration for the duration of the exposure, which can be up to a few minutes depending on the application. Depending on the hologram recording material used, the hologram recording layer can then be fixed, for example with suitable incoherent light, for example with UV light. The liquid photopolymer, for example, only hardens during exposure and subsequent fixation with UV light. After the described completion of the hologram in the hologram receiving layer, the holographic master is removed from this again.

If you want to use, for example, a substrate sheet made of plastic or glass that is bent to the shape of a front sheet, z. B. a rigid glass pane of this shape or a complementary curved rigid holographic master usually geometric tolerances of several tenths of a millimeter. The layer thickness of the hologram recording layer, in particular of the liquid photopolymer, is to be set with an accuracy of less than 10 micrometers in this hologram recording method, i.e. H. 10 to 100 times more accurate than the typical geometry tolerance of the surfaces involved. This makes a geometric tolerance compensation between the substrate wafer and the holographic master important, because on the one hand the master has to be in full contact with the hologram recording layer for the duration of the hologram recording and on the other hand the distance between the master and the substrate wafer determines the mentioned layer thickness of the hologram recording layer. For this purpose, a geometry compensation can also be implemented for the hologram recording in planar geometry, since flat surfaces are also generally subject to tolerances.

In the following, some examples of the mentioned geometry tolerance compensation for hologram production by means of a holographic master within the scope of the present method are given.

• - die Substratscheibe mit der darauf oder darin ausgebildeten Hologrammaufnahmeschicht mit einer geeigneten Kraft gegen den Holografie-Master gedrückt oder gezogen wird, so dass durch elastisches Verhalten der Substratscheibe Geometrietoleranzen zwischen dem Holografie-Master und der Substratscheibe ausgeglichen werden und ein durchgehender Flächenkontakt dazwischen mit einer im Wesentlichen konstanten vorbestimmten Schichtdicke der Hologrammaufnahmeschicht hergestellt wird, und
• - die Hologrammaufnahmeschicht in dieser Hologrammaufnahmeanordnung mit einem kohärenten Licht zum Ausbilden eines durch den Holografie-Master definierten Hologramms in der Hologrammaufnahmeschicht belichtet wird.

In a specific embodiment, the substrate wafer is made of a suitable plastic, for example polycarbonate, and is formed with a thickness such that it can be elastically bent to a predetermined extent in a manner suitable for compensating for geometrical tolerances. In comparison to a substrate wafer made of thick glass, in particular the risk of damage, such as glass breakage, etc., can be significantly reduced during handling during the entire process at hand and in particular during hologram generation. In this case, a rigid (ie rigid, stiff, in contrast to the substrate wafer not elastic) holographic master with a flat (first embodiment above) or predetermined curved (second embodiment above) geometry corresponding to the geometry of the substrate wafer can be used for the exposure, by doing

• - The substrate wafer with the hologram recording layer formed thereon or in it is pressed or pulled against the holographic master with a suitable force, so that the elastic behavior of the substrate wafer compensates for geometric tolerances between the holographic master and the substrate wafer and a continuous surface contact between them with an im Substantially constant predetermined layer thickness of the hologram recording layer is produced, and
• the hologram receiving layer in this hologram receiving arrangement is exposed to a coherent light for forming a hologram defined by the holographic master in the hologram receiving layer.

• - indem die Substratscheibe noch ohne Hologrammaufnahmeschicht mit einer geeigneten Kraft gegen die Abstandshalter des Holografie-Masters gedrückt oder gezogen wird, so dass Geometrietoleranzen zwischen dem Holografie-Master und der Substratscheibe ausgeglichen werden und ein im Wesentlichen konstanter Abstand dazwischen zur Aufnahme der Hologrammaufnahmeschicht eingestellt wird,
• - wonach das Hologrammaufnahmematerial zwischen den Holografie-Master und die Substratscheibe mit einer dem eingestellten Abstand entsprechenden vorbestimmten Dicke formschlüssig eingebracht wird und die dadurch gebildete Hologrammaufnahmeschicht in dieser Hologrammaufnahmeanordnung mit einem kohärenten Licht zum Ausbilden eines durch den Holografie-Master definierten Hologramms in der Hologrammaufnahmeschicht belichtet wird.

In a further development of this embodiment, the holographic master can additionally have one or more spacers for defining a predetermined layer thickness of a hologram recording layer to be formed between the holographic master and the substrate wafer. In this case, the holographic master is also used when applying the hologram recording layer, in particular a liquid photopolymer layer, to the substrate wafer,

• - by pressing or pulling the substrate wafer with a suitable force against the spacers of the holographic master, still without the hologram receiving layer, so that geometric tolerances between the holographic master and the substrate wafer are compensated and a substantially constant distance between them is set for receiving the hologram receiving layer,
• - after which the hologram recording material between the holographic master and the substrate wafer is introduced in a form-fitting manner with a predetermined thickness corresponding to the set distance and the hologram recording layer thus formed is exposed in this hologram recording arrangement with a coherent light to form a hologram defined by the holographic master in the hologram recording .

• - ein aufblasbares Kissen mit einer durch Druckeinwirkung verformbaren Kissenoberfläche, die zu einer vorbestimmten Soll-Geometrie einer Substratoberfläche oder mit einer vorbestimmten Abweichung von dieser vorgeformt ist, bereitgestellt; und
• - ein Holografie-Master in Form einer flexiblen Dünnschicht auf die verformbare Kissenoberfläche aufgebracht, gegebenenfalls auch damit befestigt, und zur Belichtung verwendet wird, indem
• - der flexible Holografie-Master an die Substratscheibe mit einer darauf aufgebrachten oder darin eingebetteten Hologrammaufnahmeschicht mittels der durch geeignete Druckeinwirkung zur individuellen Ist-Geometrie der Substratscheibe verformten Kissenoberfläche angedrückt oder angelegt wird, wodurch ein durchgehender Flächenkontakt dazwischen mit einer im Wesentlichen konstanten vorbestimmten Schichtdicke der Hologrammaufnahmeschicht erzielt wird, und
• - die Hologrammaufnahmeschicht in dieser Hologrammaufnahmeanordnung mit einem kohärenten Licht zum Ausbilden eines durch den Holografie-Master definierten Hologramms in der Hologrammaufnahmeschicht belichtet wird.

In an alternative embodiment, the holographic master is designed to be flexible, in order to enable the compensation of geometrical tolerances with a three-dimensionally curved or else flat substrate disc, which in particular can also be rigid. For this purpose:

• - an inflatable cushion having a pressure-deformable cushion surface which is preformed to a predetermined target geometry of a substrate surface or with a predetermined deviation therefrom is provided; and
• - A holographic master in the form of a flexible thin layer is applied to the deformable pad surface, possibly also attached with it, and used for exposure by
• the flexible holographic master is pressed or applied to the substrate wafer with a hologram recording layer applied or embedded therein by means of the cushion surface deformed by suitable pressure to the individual actual geometry of the substrate wafer, whereby a continuous surface contact between them with an essentially constant predetermined layer thickness of the hologram recording layer is achieved, and
• the hologram receiving layer in this hologram receiving arrangement is exposed to a coherent light for forming a hologram defined by the holographic master in the hologram receiving layer.

The substrate surface mentioned here is that surface of the substrate wafer which, in the finished wafer composite, faces the individual wafer or the partial composite. The predetermined target geometry of this substrate surface corresponds to the flat geometry in the above first embodiment and to the predetermined curved geometry of the substrate wafer in the above second embodiment.

The inflatable cushion can for example be filled with a fluid, in particular air, and have at least one pressure regulating valve for setting a fluid pressure in the cushion. In principle, the fluid can be any gas, but alternatively it can also be a liquid. The cushion is initially provided with a predetermined first fluid pressure, for example an underpressure or overpressure with respect to atmospheric pressure, at which the deformable cushion surface has the above-mentioned target geometry or a predetermined deviation from this, for example under-cambered or over-cambered. The deformation of the preformed cushion surface to the actual geometry of the substrate surface is now brought about by a fluid pressure change in the cushion to a predetermined second fluid pressure, for example atmospheric pressure, while the cushion with the holographic master applied to it rests against the substrate surface with the hologram recording layer applied to it or is pressed against it on the back. This fluid pressure change inside the cushion, which is carried out, for example, by actuating the pressure regulating valve, results in a uniform application of pressure to the deformable cushion surface, whereby it clings to the comparatively thin hologram recording layer on the substrate surface and thereby adopts the actual geometry of the substrate surface.

Alternatively, the inflatable cushion can be filled with a fluid, in particular air or another gas or liquid, and a solid material contained or distributed therein, the solid material being soft and malleable in the presence of the fluid in the cushion and becoming hard when fluid is withdrawn from the cushion and holds a shape impressed on it. For example, the cushion can have a loose filling made of fine granules, in particular plastic balls of suitable size, which become hard when air is extracted from the cushion, since the individual granules are pressed against one another by the negative pressure. However, the filling can also be a suitable moldable foam-like material which hardens when evacuated and holds its shape. For example, it can have a suitable connection for a vacuum pump for the removal of fluid from the cushion. Here, too, the cushion is initially provided with a cushion surface that is preformed in relation to the target geometry or with a predetermined deviation therefrom, for example under-cambered or over-cambered. The deformation of the preformed cushion surface to the actual geometry is now brought about by pressing the back of the cushion, with or without the holographic master applied to it, against the substrate surface, with or without the hologram recording layer applied to it, and a shape impressed on the deformable cushion surface, namely the actual -Geometry of the substrate surface, held or frozen or preserved by fluid removal from the cushion of the hardened solid material and retained during the implementation of the remaining steps of the present hologram production process.

• - Bereitstellen eines Teilverbunds, der mehrere miteinander bereits laminierte Scheiben umfasst und beispielsweise eine fertige herkömmliche VSG-Scheibe (Verbund-Sicherheitsglas) aus zwei durch eine reißfeste und zähelastische PVB-Folie (Polyvinylbutyral) verbundenen Glasscheiben ist. Alternativ kann eine Einzelscheibe, beispielsweise eine fertige herkömmliche ESG-Scheibe (Einscheiben-Sicherheitsglas), bereitgestellt werden. Dieser Teilverbund bzw. diese Einzelscheibe besitzt bereits die vorbestimmte gebogene Geometrie, die auch der künftige Scheibenverbund beibehalten soll, und kann insbesondere bei den nachfolgend beschriebenen Bedingungen des vorliegenden Verfahrens (schonender Laminationsprozess) starr sein;
• - Aufbringen eines fertigen Hologramms/HOE in Form einer Folie auf eine Substratscheibe, die eine flache Kunststoff- oder Dünnglasscheibe ist, insbesondere mittels eines geeigneten Klebstoffs; und
• - Verbinden der auf diese Weise mit dem Hologramm ausgestatteten Substratscheibe mit der Einzelscheibe oder dem Teilverbund mittels einer Verbindungschicht, insbesondere aus PVB oder einem anderen Schmelzklebestoff mit einer geeigneten niedrigen Aktivierungstemperatur, zu einem die vorbestimmte gebogene Geometrie aufweisenden Scheibenverbund durch einen das Hologramm schonenden Laminationsprozess, bei dem die Temperatur eine vorbestimmte Höchsttemperatur und/oder der Druck einen vorbestimmten Höchstdruck nicht überschreiten;
• - wobei das Hologramm im fertigen Scheibenverbund zwischen der Substratscheibe und der Einzelscheibe bzw. dem Teilverbund angeordnet ist und daher durch die Substratscheibe nach außen geschützt bleibt. Eine für einen konkreten Anwendungsfall erforderliche Beständigkeit des Hologramms gegenüber der Alterung kann durch eine geeignete Wahl des Materials und/oder der Dicke der Substratscheibe gewährleistet werden.

As an alternative to the first variant of the method described up to then, in which the hologram is generated directly in / on the substrate wafer, the method comprises the following steps according to a second variant:

• Provision of a partial composite which comprises several panes already laminated to one another and is, for example, a finished conventional VSG pane (laminated safety glass) made of two panes of glass connected by a tear-resistant and viscoplastic PVB film (polyvinyl butyral). Alternatively, a single pane, for example a finished conventional ESG pane (toughened safety glass), to be provided. This partial composite or this individual pane already has the predetermined curved geometry, which the future pane composite should also retain, and can be rigid in particular under the conditions of the present method described below (gentle lamination process);
• Applying a finished hologram / HOE in the form of a film to a substrate wafer, which is a flat plastic or thin glass wafer, in particular by means of a suitable adhesive; and
• - Connecting the substrate wafer equipped with the hologram in this way to the individual wafer or the partial composite by means of a connecting layer, in particular made of PVB or another hot-melt adhesive with a suitable low activation temperature, to form a wafer composite having the predetermined curved geometry by a lamination process that is gentle on the hologram that the temperature does not exceed a predetermined maximum temperature and / or the pressure does not exceed a predetermined maximum pressure;
• the hologram is arranged in the finished composite disk between the substrate disk and the individual disk or the partial composite and therefore remains protected from the outside by the substrate disk. A resistance of the hologram to aging that is required for a specific application can be ensured by a suitable choice of the material and / or the thickness of the substrate wafer.

In addition, all the features and effects described above for the first variant of the method also apply mutatis mutandis to this second variant.

One idea here is also to outsource the integration of a hologram, for example an HOE, from the lamination process of the (vehicle) glazing in a separate process step that can be carried out at lower temperatures and / or pressures and in which the hologram together with a substrate pane that protects and supports this is gently deformed against a (vehicle) pane, an individual pane or a partial composite, which already has the required curved geometry and is connected / laminated to it. In contrast to the first variant above, the hologram is here not originally produced on this substrate wafer, but separately in the form of a flat sheet or a flat film in a manner known per se and only subsequently connected to the substrate wafer with or without adhesive (one or both of these two steps may or may not be part of the present procedure).

With this second variant of the method, a hologram in the form of a film can therefore be applied to a laminated safety glass or ESG pane with little crease or crease. For example, a flat thin glass pane is used as the substrate pane, to which the HOE film is applied with the aid of an adhesive system with a low activation temperature. Furthermore, the same or a different adhesive system can be applied to the HOE film, which makes subsequent application to conventional vehicle glazing possible at low activation temperatures. Here, too, the HOE film is deformed together with the thin glass substrate against the vehicle glazing and firmly connected by the adhesive system. For this purpose, the thin glass can be designed as described above for the first variant.

In the method of the type set out herein, the predetermined maximum temperature for realizing the gentle lamination process can be increasingly preferred, for example, in the following order: no more than 130 ° C, than 120 ° C, than 110 ° C, than 100 ° C, than 90 ° C, than 80 ° C, than 70 ° C, or than 60 ° C. The lower the temperature remains during the gentle lamination process, the lower the different thermal expansions of the various materials involved and thus the lower the likelihood of creasing or creasing of the hologram layer or film.

In the method of the type set out herein, the predetermined maximum pressure can, for example, be increasingly preferred in the following order: no more than 14 bar, than 13 bar, than 12 bar, than 11 bar, than 10 bar, than 9 bar, than 8 bar, than 7 bar, or than 6 bar. The lower the pressure remains during the gentle lamination process, the less likely there is a probability of damage to the hologram associated with an increase in pressure.

• - einen bereits vor dem schonenden Laminationsprozess vorliegenden Teilverbund aus mehreren miteinander laminierten Scheiben oder eine Einzelscheibe, jeweils mit der vorbestimmten gebogenen Geometrie, sowie
• - eine Substratscheibe, die bereits vor dem schonenden Laminationsprozess mit einem darauf oder darin in einer Hologrammaufnahmeschicht erzeugten Hologramm ausgestattet bzw. mit einem fertigen Hologramm in Form einer Folie flächig verbunden worden ist,
• - welche miteinander durch den genannten das Hologramm schonenden Laminationsprozess mittels einer Verbindungsschicht zu dem Scheibenverbund mit der vorbestimmten gebogenen Geometrie verbunden sind,
• - wobei das Hologramm in dem Scheibenverbund durch die Substratscheibe nach außen geschützt bleibt, indem es zwischen der Substratscheibe und der Einzelscheibe bzw. dem Teilverbund angeordnet oder in der Substratscheibe eingebettet ist.

According to a further aspect, a composite pane with a predetermined curved geometry, in particular a vehicle pane, is provided in which a hologram, in particular a holographic optical element, has been integrated according to a method of the type set forth herein. In particular, a composite pane of the type set out herein can thus comprise the following:

• - a sub-assembly made up of several panes laminated to one another or a single pane, each with the predetermined curved geometry, which is already present before the gentle lamination process, as well
• - a substrate wafer which has already been equipped with a hologram produced on or in a hologram receiving layer before the gentle lamination process or has been connected to a finished hologram in the form of a film,
• - which are connected to one another by the said lamination process, which is gentle on the hologram, by means of a connecting layer to form the pane composite with the predetermined curved geometry,
• - The hologram in the composite disk remains protected from the outside by the substrate disk, in that it is arranged between the substrate disk and the individual disk or the partial composite or is embedded in the substrate disk.

In particular, the conventional glass structure of laminated safety glass can be replaced by a hybrid glass-plastic structure in that the substrate pane made of plastic is connected to a single pane of glass using the method of the type set out here. In contrast to conventional laminated glass with the "glass / PVB film / glass" structure, this results in a glass-plastic hybrid pane with a "glass / PVB film / hologram layer / plastic substrate disc / surface coating" structure. A surface finish, such as. B. a hardcoat for better material resistance to scratches, etc., for example towards the interior of a vehicle, can be optionally provided. The hologram layer can e.g. B. be a hologram receiving layer made of photopolymer with a hologram formed therein. The plastic substrate wafer can, for. B. consist of polycarbonate.

According to a further aspect, a vehicle is provided with a vehicle window, the vehicle window being at least partially formed by a laminated pane produced according to the present method. The vehicle can be any land, air or water vehicle, in particular a motor vehicle. The substrate pane equipped with the hologram can in particular be an inner pane of the vehicle pane that is closer to or directly to a vehicle interior, while the individual pane or the partial composite is an outer pane of the vehicle pane that is closer to or directly to the exterior of the vehicle. In addition to this inner and outer pane, the vehicle window can, but does not have to, have layers or panes located further inside or outside in the pane composite.

Figure list

• 1 ein Flussdiagramm des Verfahrens der hierin dargelegten Art zum Integrieren eines Hologramms in einem Scheibenverbund mit einer vorbestimmten gebogenen Geometrie;
• 2 in einer schematischen Querschnittsansicht einen Abschnitt eines mit dem Verfahren gemäß 1 erhaltenen Scheibenverbunds einer vorbestimmten gebogenen Geometrie, insbesondere einer Fahrzeugscheibe, bei dem das Hologramm zwischen einer herkömmlichen VSG-Scheibe und einer Substratscheibe integriert ist;
• 3 in einer schematischen Querschnittsansicht einen Abschnitt eines mit dem Verfahren gemäß 1 erhaltenen Scheibenverbunds einer vorbestimmten gebogenen Geometrie, insbesondere einer Fahrzeugscheibe, bei dem das Hologramm zwischen einer herkömmlichen ESG-Scheibe und einer Substratscheibe integriert ist; und
• 4 in einer schematischen Querschnittsansicht einen Abschnitt eines mit dem Verfahren gemäß 1 erhaltenen Scheibenverbunds einer vorbestimmten gebogenen Geometrie, insbesondere einer Fahrzeugscheibe, bei dem das Hologramm in einer mit der herkömmlichen ESG- oder VSG-Scheibe verbundenen Substratscheibe eingebettet ist.

The above aspects of the invention and its embodiments and specific configurations are explained in more detail below with reference to the examples shown in the accompanying drawings. The drawings are purely schematic; in particular, they should not be read as being true to scale. Show it:

• 1 a flowchart of the method of the type set forth herein for integrating a hologram in a composite pane with a predetermined curved geometry;
• 2 in a schematic cross-sectional view a portion of a with the method according to FIG 1 obtained pane composite of a predetermined curved geometry, in particular a vehicle pane, in which the hologram is integrated between a conventional VSG pane and a substrate pane;
• 3rd in a schematic cross-sectional view a portion of a with the method according to FIG 1 obtained pane composite of a predetermined curved geometry, in particular a vehicle pane, in which the hologram is integrated between a conventional ESG pane and a substrate pane; and
• 4th in a schematic cross-sectional view a portion of a with the method according to FIG 1 obtained pane composite of a predetermined curved geometry, in particular a vehicle pane, in which the hologram is embedded in a substrate pane connected to the conventional ESG or VSG pane.

Description of embodiments

All of the various embodiments, variants and specific design features of the method according to the first aspect of the invention and the resulting composite pane of predetermined curved geometry with a hologram integrated therein and of the vehicle according to the further aspects of the invention mentioned above in the description and in the subsequent claims can with the in the in the 1 to 4th examples shown. They are therefore not all repeated again below. The same applies accordingly to the definitions of terms and effects already given above in relation to individual features that are included in the 1-4 are shown.

1 FIG. 8 shows a flow diagram of a method according to the above first aspect of FIG Invention for integrating a hologram, in this example a holographic optical element (HOE), in a composite pane of a predetermined curved geometry. The method in some of its various variants described above is explained below with reference to the methods shown in 2 to 4th schematically shown examples of the resulting composite pane 1 according to the above further aspect of the invention, in particular a windshield of a motor vehicle (not shown).

2 to 4th each show a section of a finished composite pane 1 in a greatly simplified schematic cross-sectional view, which alone illustrates its layer structure. In order to simplify the illustration, the 2 to 4th the individual layers of the pane composite 1 straight and shown with thicknesses that are not true to scale, while the three-dimensional curved geometry that the laminated panes 1 overall and therefore each of the layers shown, is not shown.

• In einem ersten Schritt S1 gemäß 1 wird eine fertige herkömmliche VSG-Scheibe als Teilverbund 2 aus zwei durch eine reißfeste und zähelastische PVB-Folie 3 verbundenen Glasscheiben 4 und 5 bereitgestellt. Dieser Teilverbund 2 besitzt beim Schritt S1 bereits die vorbestimmte gebogene Geometrie, die auch der künftige Scheibenverbund 1 beibehalten soll.

In the pane composite 1 according to the 2 the HOE is integrated between a laminated safety glass pane, which can for example be conventional vehicle glazing, and a substrate pane, which is achieved in particular by the following process sequence according to FIG 1 can be achieved:

• In a first step S1 according to 1 is a finished conventional laminated safety glass pane as a partial composite 2 made of two with a tear-resistant and tough elastic PVB film 3rd connected panes of glass 4th and 5 provided. This sub-network 2 in step S1 already has the predetermined curved geometry that the future composite pane will also have 1 should be retained.

In a further step S2, a substrate wafer is made 6th provided and on their in 2 left substrate surface a hologram recording layer 7th , in this example made of liquid photopolymer. In a subsequent step S3, in the hologram recording layer 7th the desired HOE is generated by a suitable exposure process with a coherent light, for example by using a suitable holographic master, as set out in detail above, which is then covered by the exposed and optionally fixed with UV light hologram recording layer 7th is removed again.

As again described in detail above, the substrate wafer can 6th in step S2, for example, as a thick or thin glass or plastic pane, which also already has the predetermined curved geometry of the future pane composite 1 Has. Alternatively, the substrate wafer 6th in step S2 but also as a thin glass pane or as a thin plastic pane initially provided with a flat geometry and equipped with the HOE in step S3, and only then in a step S4 in a lamination process that is gentle on the hologram to the curved geometry of the composite 2 to be deformed.

In both of these cases, the substrate wafer 6th in the subsequent step S4 together with that in the hologram receiving layer 7th generated HOE with the sub-network 2 by means of a connecting layer 8, in particular made of PVB or another hot-melt adhesive with a suitable low activation temperature, to the pane composite having the predetermined curved geometry 1 connected by a lamination process that is gentle on the hologram, in which the temperature does not exceed a predetermined maximum temperature and / or the pressure does not exceed a predetermined maximum pressure.

In the pane composite thus created 1 is the hologram / HOE between the substrate wafer 6th and the sub-network 2 arranged and thus remains through the substrate wafer 6th , which are an integral part of the composite pane 1 is protected from the outside.

How 3rd shows, can alternatively in the above step S1 instead of the partial composite 2 a single disc 20th , for example a finished conventional ESG pane (toughened safety glass), can be provided with the predetermined curved geometry. Incidentally, the procedure can also be used here as with reference to 2 as described.

4th shows one to 2 or to 3rd possible alternative in which the hologram layer 7th not on the substrate wafer 6th arranged, but is embedded therein, as described in detail above. Incidentally, the procedure can also be used here as with reference to 2 or 3rd expire. Here, too, the hologram / HOE remains in the pane composite thus created 1 through the substrate wafer 6th , which are an integral part of the composite pane 1 and surrounds the HOE all around, protected from the outside.

As an alternative to exposing the hologram, in this example the HOE, directly on the substrate wafer 6th can the pane composite 1 the 2 or 3rd also by the second variant of the method according to FIG 1 are generated, in which the hologram / HOE in step S3 as a separately produced finished film 70 is provided, which in step S2 on the provided substrate wafer 6th is applied directly or by means of a suitable adhesive. So in this case Step S3 performed before step S2. For the rest, the method can also be used here as above with reference to 2 or 3rd as described.

List of reference symbols

1

Laminated panes with the predetermined curved geometry

2

Partial composite (e.g. VSG) with the predetermined curved geometry

20th

Single pane (e.g. ESG) with the predetermined curved geometry

3

Tear-resistant and tough elastic PVB film in a partial composite

4th

first glass pane of the partial composite

5

second glass pane of the partial composite

6th

Substrate disc

7th

Hologram receiving layer (e.g. liquid photopolymer)

70

separately produced HOE or hologram film

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely 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

• US 4998784 A [0004]

Claims (12)

Method for integrating a hologram, in particular a holographic optical element, in a pane composite (1) of a predetermined curved geometry, in particular in a vehicle pane, with the steps: - Providing (S1) a partial composite (2) which comprises several panes (4, 5) already laminated with one another, or a single pane (20) which already has the predetermined curved geometry; - Providing (S2, S3) a substrate wafer (6) with a hologram recording layer (7) applied thereon or embedded therein, in particular made of liquid photopolymer, in which the hologram is then generated by a suitable exposure process; and - Connection (S4) of the substrate wafer (6) thus equipped with the hologram to the individual wafer (20) or the partial composite (2) by means of a connecting layer (8) to form a composite wafer (1) having the predetermined curved geometry by a lamination process that is gentle on the hologram at which the temperature does not exceed a predetermined maximum temperature and / or the pressure does not exceed a predetermined maximum pressure; - The hologram in the composite pane (1) remains protected from the outside by the substrate pane (6) by being arranged between the substrate pane (6) and the individual pane (20) or the partial composite (2) or in the substrate pane (6) is embedded. Procedure according to Claim 1 - The substrate disk (6) is provided as a flat plastic or thin glass disk which, together with the hologram formed thereon or in it, by connection with the individual disk (20) or the partial composite (2) to the predetermined curved geometry that these have, is deformed. Procedure according to Claim 1 - The substrate wafer (6) itself is also already provided with the predetermined curved geometry. Method according to one of the preceding claims, wherein the substrate disc (6) is made of plastic and the hologram recording layer (7) is embedded therein by using a hologram recording material, for example a photopolymer, - is / is or is dissolved and / or embedded in a plastic matrix of the substrate wafer (6) - formed as an inner layer consisting of the hologram recording material in a multi-stage manufacturing process of the substrate wafer (6) and is / is in particular surrounded by plastic on all sides. The method according to any one of the preceding claims, wherein - The substrate disk (6) is made of plastic, so that it can be elastically bent to a predetermined extent; and - A rigid holographic master with a flat or predetermined curved geometry corresponding to the geometry of the substrate wafer (6) is used for exposure by - The substrate disc (6) with the hologram recording layer (7) formed thereon or in it or already previously with a suitable force is pressed or pulled against the holographic master, so that the elastic behavior of the substrate disc (6) geometry tolerances between the holographic master and the substrate wafer (6) are compensated and a continuous surface contact is established therebetween with a substantially constant predetermined layer thickness of the hologram recording layer (7), and - The hologram recording layer (7) in this hologram recording arrangement is exposed to a coherent light for forming a hologram defined by the hologram master in the hologram recording layer (7). Procedure according to Claim 5 , wherein - the holographic master additionally has spacers for defining a predetermined layer thickness of a hologram recording layer (7) to be formed between the holographic master and the substrate wafer (6) and - even when the hologram recording layer (7), in particular a liquid photopolymer layer, is applied the substrate wafer (6) is used by pressing or pulling the substrate wafer (6) with a suitable force against the spacers of the holographic master before the application of the hologram recording layer (7), so that geometrical tolerances between the holographic master and the substrate wafer (6) are compensated and a substantially constant distance between them for receiving the hologram recording layer (7) is set, - after which the hologram recording material between the holographic master and the substrate disc (6) with a predetermined constant thickness corresponding to the set distance is introduced in a form-fitting manner t and the hologram recording layer (7) formed thereby is exposed in this hologram recording arrangement with a coherent light for forming a hologram defined by the holographic master in the hologram recording layer (7). Method according to one of the Claims 1 to 4th , wherein - an inflatable cushion with a deformable cushion surface by the action of pressure, which into a predetermined target geometry of a substrate surface or is preformed with a predetermined deviation therefrom, is provided; and - a holographic master in the form of a flexible thin layer is applied to the deformable pad surface and used for exposure by - the flexible holographic master on the substrate disc (6) with a hologram recording layer (7) applied to it or embedded therein by means of the suitable The application of pressure to the individual actual geometry of the substrate wafer (6) is pressed or applied to the deformed cushion surface, whereby a continuous surface contact between them with an essentially constant predetermined layer thickness of the hologram recording layer (7) is achieved, and - the hologram recording layer (7) in this hologram recording arrangement with a coherent light is exposed to form a hologram defined by the holographic master in the hologram receiving layer (7). Method for integrating a hologram, in particular a holographic optical element, in a pane composite (1) of a predetermined curved geometry, in particular in a vehicle pane, with the steps: - Providing (S1) a partial composite (2) which comprises several panes (4, 5) already laminated with one another, or a single pane (20) which already has the predetermined curved geometry; - Application (S2, S3) of a hologram in the form of a film (70) on a substrate disk (6) which is a flat plastic or thin glass disk, in particular by means of an adhesive; and - Connection (S4) of the substrate wafer (6) thus equipped with the hologram to the individual wafer (20) or the partial composite (2) by means of a connecting layer (8) to form a composite wafer (1) having the predetermined curved geometry by a lamination process that is gentle on the hologram at which the temperature does not exceed a predetermined maximum temperature and / or the pressure does not exceed a predetermined maximum pressure; - wherein the hologram is arranged in the pane composite (1) between the substrate pane (6) and the individual pane (20) or the partial composite (2) and thus remains protected from the outside by the substrate pane (6). Method according to one of the preceding claims, wherein the predetermined maximum temperature is not more than 120 ° C, in particular not more than 100 ° C, preferably not more than 80 ° C, particularly preferably not more than 60 ° C. Method according to one of the preceding claims, wherein the predetermined maximum pressure is not more than 12 bar, in particular not more than 10 bar, preferably not more than 8 bar, particularly preferably not more than 6 bar. Pane composite (1) with a predetermined curved geometry, in particular a vehicle pane, with a hologram integrated therein according to a method according to one of the preceding claims, in particular a holographic optical element, comprising: - A partial composite (2) already present before the gentle lamination process and made up of several panes (4, 5) laminated to one another or a single pane (20), each with the predetermined curved geometry, as well as - a substrate disc (6) which has already been equipped with a hologram produced on it or in it in a hologram receiving layer (7) or has been connected to a hologram in the form of a film (70) before the gentle lamination process, - which are connected to one another by the said lamination process, which is gentle on the hologram, by means of a connecting layer (8) to form the laminated pane (1) of the predetermined curved geometry, - The hologram in the composite pane (1) remains protected from the outside by the substrate pane (6) by being arranged between the substrate pane (6) and the individual pane (20) or the partial composite (2) or in the substrate pane (6) is embedded. Vehicle with a vehicle window which is at least partially covered by a laminate (1) according to Claim 11 The substrate pane (6) equipped with the hologram is an inner pane of the vehicle pane that is closer to or directly to a vehicle interior, while the individual pane (20) or the partial composite (2) is an outer pane that is closer to or directly to the exterior of the vehicle the vehicle window is.

Images