WO2011042135A1

WO2011042135A1 - An arrangement of light polarizing window panes

Info

Publication number: WO2011042135A1
Application number: PCT/EP2010/006006
Authority: WO
Inventors: Donald Press; Marten Walther
Original assignee: Schott Ag
Priority date: 2009-10-05
Filing date: 2010-10-01
Publication date: 2011-04-14

Abstract

A device, comprising - at least one first pane-like element (3) with at least one first polarizing layer (5); - at least one second pane-like element (7) with at least one second polarizing layer (9), with a distance being formed between the first pane-like element (3) and the second pane-like element (7). The device is characterized in that the first and/or the second pane-like element (3, 7) comprises at least one antireflection layer (300.1, 300.2, 300.3, 300.4).

Description

AN ARRANGEMENT OF LIGHT POLARIZING WINDOW PANES

The present invention relates to an invention with at least one first and one second pane-like element, comprising polarizing layers, and the use of such a device.

There is a necessity especially in medical and security-related institutions to monitor persons in an adjacent room from a monitoring room. When it is necessary to monitor from the monitoring room not only one adjoining room but several adjoining rooms then this will lead to the problem that although the person in the monitoring room is to observe the persons in the surrounding rooms, the persons to be monitored in the different rooms should be unable to have visible contact with each other. A device for application in a radio therapy device has become known from JP 2009/008445 in which persons can be monitored in different rooms from a monitoring room by X-ray screening window panes which are provided with polarization foils. The disadvantageous aspect in JP 2009/008445 is that the application is limited merely to radio therapy.

It was a further problem of the device according to JP 2009/008445 that when the same light conditions prevail in all separated rooms, i.e. the rooms with the persons to be monitored which are separated by the device and the control room per se, the translucency through the pane provided with the polarizing layer is possible only within limits because the difference in contrast is low under the same light conditions.

In order to solve this problem, the invention proposes a device comprising at least one first pane-like element with at least one first polarizing layer and one second pane-like element with at least one second polarizing layer, with a space being formed between the at least one first pane-like element and the second pane-like element, to provide the first and/or second pane-like element with an antireflection layer. It is understood that more than two pane-like elements would be possible which are adjacent to the monitoring room defined by the distance between the individually spaced pane-like elements. Principally, the principle in accordance with the invention to prevent translucency from one room with a person to be monitored to another room with a person to be monitored only works with two separate rooms. When the principle is applied in more than two rooms, two rooms each belong to one group of rooms and in the group of rooms the groups must be separated from one another by other measures.

By providing the device with at least one antireflection layer or antireflection coating, the reflection in the visible wavelength range of 380 nm to 800 nm of a pane-like element provided with a polarizing device, especially a polarizing foil, and the contrast over devices with pane-like elements according to the state of the art is increased considerably. Preferably, the reflection factor R_VIS is reduced by the antireflection layer by 10% to 4% in relation to a pane-like element not provided with an antireflection layer. If the reflection factor R_vis of the pane-like element without antireflection layer is 8% for example, the reflection factor R_vis can be reduced by the antireflection layer to 0.0% to 6%, preferably to 0.3% to 2%. The previously mentioned reflection factor R_Vj_S concerns a reflection factor at standard light D65 (artificial daylight), folded with the sensitivity of the human eye. Although the reflection can be larger than 2% for example for individual wavelengths, a value R_vis of 1 % or less can be obtained for standard light D65.

By avoiding the reflection, the contrast is increased considerably over an element not provided with an antireflection layer. Interference layer systems are preferably used as antireflection layers. Light is reflected at the boundary surfaces of the antireflection layer in such systems. The waves reflected at the boundary layers can even extinguish completely by interference when the phase and amplitude conditions are fulfilled. As a guideline the antireflective layers are placed preferentially at any interface, between the pane like element (typically glass or polymer with an elevated refractive index (n >1 ,35) in comparison to air (n = 1)) and the surrounding Air/athmosphere with low refractive index. At this position the most disturbing reflections occur.

Such antireflection layers have been realized in the products AMIRAN,

CONTURAN or MIROGARD of Schott AG. Reference is also hereby made to EP- A-1248959 concerning an interference layer system for broadband antireflection, the scope of disclosure of which is included fully in the present application.

An interference layer system for antireflection can be a triple-layer system in which the individual layers are applied with the help of sol-gel technology. Preferably, the application occurs successively with the same method, with an antireflection layer being formed by suitable setting of refractive index and thickness of the three layers. An example for such an antireflection layer coated on float glass with a refractive index of 1.5 (see the glass "Optifloat" in Pilkington's 2009 glass manual) is a layer system with a first layer with a refractive index between 1.6 and 1.8, a second layer with a refractive index of 1.9 and 2.5 and a third layer with a refractive index of between 1.4 and 1.55. By providing a respective setting of the layer thicknesses, it is possible to realize R_Vi_S reflectivities at D65 standard light of less than 1% in such a system. Other application methods for the layers are the sputtering method or the CVD method. The person skilled in the art knows adjusted sequences of layers for other glasses whose refractive indexes differ partly considerably from float glass with which comparatively low reflectivities are achieved. In addition to the reduction of the reflection, an increase of the transmission preferably by up to 10% can be achieved by the antireflection layer.

The polarizing layer is arranged as a polarizing foil in a special embodiment of the invention. Examples for polarizing foils are polarizing foils of American Polarizers, Inc., 141 South Seventh Street, Reading, Pennsylvania, USA. Preferably, the first pane-like element is a first laminate with a first and second pane of the first pane-like element. In an arrangement as a laminate it is possible to arrange the polarizing layer, especially the polarizing foil, between the first and second pane. It is understood that the first laminate can also comprise more than two panes, thus forming a multiple laminate. The polarizing layer or foil is then introduced between two of the several panes of the multiple laminate. It is understood, that a laminate typically contains polymeric bonding layers, such as PVB, EVA, TPU, epoxy resins or special glueing systems, to join the different pane like elements with the polarizer. Typical polymers used in the industry are

Polyvinylbutyral (PVB) as for example the products Trosifol, BG or Trosifol, SC (Soundcontrol) as supplied by the company Kuraray Europe GmbH, DIVISON TROSIFOL, Muelheimer Strasse 26 ,53840 Troisdorf or alternatively

Ethylenvinylacetat (EVA) as supplied as product Vistasolar supplied by Solutia, ETIMEX Solar GmbHJndustriestraGe 3.D-89165 Dietenheim or alternatively Polyurethane (TPU), Product DUREFLEX, as delivered by Bayer MaterialScience AG, Kaiser-Wilhelm-Allee, D-51373 Leverkusen.

Alternatively the industry supplies polarizer foils with direct glueing systems attached, that are directly applied onto glass surfaces, as used typically in the LCD industry.

In accordance with the first pane-like element, all further pane-like elements, especially also the second pane-like element, can be arranged as a second laminate with a third and fourth pane. This ensures that the polarizing foil is arranged between the third and fourth pane even in the further pane-like elements, e.g. the second laminate.

If the polarizing foil is introduced between the panes, as in laminates, at least one and preferably both outside panes of the laminate is provided with an antiref lection layer, which means the antireflection layer is arranged in a device with two laminates on one or several of the following surfaces: one outside of the first pane of the first laminate;

one outside of the second pane of the first laminate;

one outside of the third pane of the second laminate;

one outside of the fourth pane of the second laminate.

In a special embodiment of the invention, both the outside as well as the inside of a pane of a laminate can be provided with a porous antireflection layer. In such a case, the porous antireflection layer on the inside soaks up the material of the laminate, i.e. casting resin, EVA or PVB, so that the antireflection effect is lifted on the inside, i.e. the inwardly disposed boundary surface, and the antireflection effect is only achieved on the outside.

The polarizing foil is not introduced mandatorily between two panes, which means within a laminate, but can also be applied to a glass or plastic pane for example. The pane is preferable when it does not concern a laminate, a pretensioned safety glass (ESG).

When the polarizing foil is applied to a monolithic pane or an outside of a laminate, the side of the polarizing foil facing the air can be provided with an antireflection layer. Preferably the polarizer is fixed to the glass pane by a direct glueing process, similar to the LCD processes to derive an economically beneficial fabrication process. When no monolithic pane is concerned, but a device with two laminates, the antireflection layer can be connected directly or indirectly with one or several of the following surfaces:

- one outside of the first pane of the first laminate, and/or

- one outside of the second pane of the first laminate, and/or

- one outside of the third pane of the second laminate, and/or

- one outside of the fourth pane of the second laminate, depending on which of the outsides is provided with the polarizing foil.

When a pretensioned pane or other panes which have a tension are used, polarization-rotating effects can occur as a result of the inner tension in the glass or plastic. It therefore needs to be considered for the pane that all panes which are arranged between the polarizers or the polarizing layer do not cause any disturbing polarization rotations which would reduce or cancel out the effects of the polarizers or polarizing foil.

Preferably, all glass/foil transitions which face the air side are provided with an antireflection layer for high contrast in setting up. It is understood that also only one of the glass/foil transitions can be provided with an antireflection layer.

However, the optical effectiveness is lower in such an arrangement.

In order to enable the rotation of the polarization and thus to enable the view from one person to be monitored by the control room to another person to be

monitored, it is provided that the device comprises at least one polarization- rotating layer.

The polarization-rotating layer is preferably applied to the at least first and/or at least second polarizing layer, but is always oriented in such a way that it lies in the arrangement between the two polarizers or polarizing layers.

The polarization-rotating layer is especially preferably a liquid crystal layer. Such a polarization-rotating layer should be arranged on at least one pane in the region between the polarizing layers. Preferably, the liquid crystal layer can be triggered electrically, i.e. the polarization direction is turned by applying an electric voltage for example. In this way the view of one person to be monitored to another person to be monitored can be blocked or enabled.

The first pane-like element and/or the second pane-like element could comprise additional functional coatings, for example low-E coatings, easy-to-clean coatings or color effect coatings, which are well known in the state of the art. The device in accordance with the invention is preferably used in one of the following areas:

- in the area of architectural glazing, especially in the field of interior design, which can also contain an outside facade;

- in security-relevant areas, especially in prisons;

- in the health field, especially in hospitals and psychiatric institutions.

The invention will be explained below by reference to the embodiments without any limitations thereto.

The drawings show as follows:

Fig. 1 shows a first embodiment of a device in accordance with the invention; Figs. 2a, 2b show a second embodiment of a device in accordance with the invention, with a polarization-rotating layer being provided.

Fig. 3 shows transmission and reflection behavior of a pane with a polarizing foil with and without antireflection coating.

Fig. 1 shows a first embodiment of a device 1 in accordance with the invention, with the device 1 in accordance with the invention having a first pane-like element 3 with at least one first polarizing layer 5 and a second pane-like element 7 with a second polarizing layer 9. A distance A is formed between the first pane-like element 3 and the second pane-like element 7. The distance A between the first pane-like element and the second pane-like element defines an intermediate space 20 such as a monitoring room. A person is located in the monitoring room for example who observes rooms which are located behind the first pane-like element 3 or the second pane-like element 7.

Preferably, the person in the monitoring room 20 is a prison guard or a nurse, depending on the institution in which the present device is used. Possible areas of use of device 1 are especially the use in the medical field, in the psychiatric field or also in the area of prisons or jails. Preferably, the pane-like elements 3, 7 are substantially transparent or semi-transparent elements in the range of visible light, e.g. glass or plastic panes with a surface area of preferably >0.5 m², with these panes being adjustable to the conditions of a building. Substantially transparent or semi-transparent shall be understood in the present application that the glass or plastic pane has a transmission without a polarizing foil for non-polarized light in the range of 70% to 99.5% for visible wavelengths. When a polarizing foil is applied, the transmission is reduced by approximately half to values less than 50% when the polarizing foil is illuminated with non-polarized light. In such a case, half of the light, which is the undesirable pole direction, is dampened as a result of the configuration and only approx. 50% of the non-polarized light will pass the polarizing layer. In the present embodiment, the first pane-like element 3 and the second pane-like element 7 are arranged as a first laminate and as a second laminate. The first laminate comprises a first pane 30 and a second pane 40 and the second laminate comprises a third pane 50 and fourth pane 60. The first polarizing layer 5 is introduced as the first polarizing foil between the first pane 30 and the second pane 40. The polarization direction of the first polarizing foil is indicated with the direction of arrow 70. The polarizing foil is preferably introduced in such a way that no additional reflections will be produced at the transitions from the polarizing foil to the pane which is preferably arranged as a glass pane. This is achieved especially with adhesive or laminating foils with adjusted refractive index.

In the room 100 which is to be monitored and is located behind the pane there is non-polarized light. As a result of the polarizing layer 50, only polarized light of the direction 70 is allowed to pass into the monitoring room 20 from room 100. For a person disposed in the monitoring room 20, the person disposed in room 100 can be seen and vice-versa. The second pane-like element 7 is also arranged as a laminate. The second laminate comprises a third pane 50 and a fourth pane 60. A second polarizing layer 9 is disposed between the two panes 50 and 60. The second polarizing layer 9 which is arranged as a second polarizing foil is arranged in such a way that it polarizes light in the room 200 which is disposed behind the second pane-like element in a direction 80 which is orthogonally to the direction 70 of the polarizing foil in the first laminate. In a preferable configuration of the device a polarization direction of the first pane-like element 3 being essentially orthogonal to the polarization direction of the second pane-like element 7 for all visible wavelengths in the range of 380nm to 800 nm_: The direct light that passes through a device comprising a first pane-like element 3 and a second pane-like element 7 with such a configuration of crossed polarizers is less then 20%, especially less then 10%, most preferably less than 5%, especially less than 2%.

In a preferred embodiment of the device the minimum distance of the first panelike element 3 and the second pane-like element 7 is 50cm, preferably 1m, most preferably 2m in order to provide a sufficient large monitoring room 20. Furthermore, a person in the monitoring room 20 can see a person in the room 200, but the person to be monitored in room 200 can not see the person to be monitored in the opposing room 100 because the view from room 200 to room 100 is blocked by the mutually orthogonal polarization. In order to enable a good view from the monitoring room 20 both into the room 100 to be monitored and the room 200 to be monitored under the same light conditions in room 100, 200 and 20, it is provided in accordance with the invention to provide at least one, but preferably every, outside of the laminate with an antireflection layer. The antireflection layer on the first pane carries the reference numeral 300.1 , the antireflection layer on the second pane the reference numeral 300.2, the antireflection layer on the third pane the reference numeral 300.3, the antireflection layer on the fourth pane the reference numeral 300.4. The panes 30, 40, 50, 60 could be provided with an interference layer (not shown) on the inner surface of the laminate in order to join the two panes to the polarizer foil laminated between the panes. The interference layers are also designated as bonding layers. This is described in further detail with regard to example 3.

When it has been ensured that as a result of geometrical conditions a view from one room to be monitored to another room to be monitored is not possible, further panes with polarizing foils can be used to monitor not only two rooms but four rooms for example from the common monitoring room 20. In any case, the panes which are opposite of one another and enable eye contact from one monitoring person to another must be provided with polarizing foils which are polarized orthogonally with respect to each other in order to prevent a view, as described above. Such an embodiment with more than two panes is possible, but is not shown in the present application.

If the situation in the room requires, that computer monitors like LCD-monitors (which emit polarized lights) in the room 200 need to be observed from the monitoring room 20, the polarizing direction of the two pane like elements can be adjusted for example to 45°, allowing the polarized light from the LCD-monitors in room 200 to enter the monitor room 20, while still maintaining the condition, that the two pane like elements are sufficiently orthogonal to each other, so that substantially no light or only less light passing from room 200 to room 100. If a LCD-monitor (which emits polarized light) is installed in monitoring room 20 and should not be observed, e.g. from room 200, then the polarizing direction 80 of the pane 7 could be chosen such that the polarizing direction 80 is oriented

perpendicular to the polarization of the LCD monitor in the monitoring room 20. In such a case the transmission of visible light emitted by the LCD-monitor through the polarizing layer is suppressed to a level of less than 5 %, preferably less than 2 %, most preferably less than 1 %. By such a measurement spy protection of a LCD-monitor in a monitoring or security room could be obtained. The reflection of light is especially reduced by the antireflection layers 300.1 , 300.2, 300.3, 300.4, as is shown in Fig. 3, and the contrast and thus the view is improved for the monitoring person to the monitored room 100 and 200, and vice- versa from room 100 and 200 to room 20. It is especially relevant when

approximately the same light conditions prevail in all three rooms 100, 200 and 20. Antireflection layers produced with the sol-gel process or the sputtering process are used for example as antireflection layers.

Two embodiments (example 1 and example 2) for such antireflection layers will be shown below:

Example 1 :

Single-sided antireflection layer, produced according to the sol-gel method: The coating consists of three individual layers each and has the following structure: substrate + M + T + S. The individual layer marked with T contains titanium dioxide TiO₂. The individual layer marked with S contains silicon dioxide S1O2, and the individual layer marked with M is drawn from S and T mixed solutions. The float glass substrate is carefully cleaned before coating. The dip solutions are each applied in rooms air-conditioned to 28°C at an air humidity of 5 to 10 g/kg. The drawing speeds are approximately 275/330/288 mm/min for the individual layers M/T/S. A baking process under air follows the drawing of each gel layer. The baking temperatures and the baking times are 180°C/20 min after production of the first gel layer, and 440°C/60 min after the production of the second and third gel layer. In the case of T-layers, the dip solution (per liter) is composed as follows: 68 ml of titanium n-butylate, 918 ml of ethanol (abs), 5 ml of acetylacetone and 9 ml of ethyl butyl acetate. The dip solution for producing the S- layer comprises: 125 ml of silicid acid methylester, 400 ml of ethanol (abs), 75 ml of H2O (dest.), 7.5 ml of acetic acid and is diluted after a dwell period of approx. 12 hours with 393 ml of ethanol (abs). The coating solutions for producing the oxides with medium refractive index are prepared by the mixture of the S + T-solutions. The layer marked with M is drawn from a dip solution with a silicon oxide content of 5.5 g/l and a titanium dioxide content of 2.8 g/l. The applied wet-chemical sol- gel process allows the economic coating of large surfaces as a dipping method, with two panes being glued together prior to the dipping process so that the necessary antireflection effect on one side is achieved. The adhesive is chosen in such a way that it will incinerate at 440°C within the above described baking period, so that the panes will leave the process separately.

Example 2:

Single-sided antireflection layer, produced according to the sputtering process:

The coating is coated in a continuous-flow system with an MF sputtering process by magnetron sputtering, with the substrate being positioned on a so-called carrier and is transported on the same through the sputtering system. Within the coating system, the substrate is preheated at first to approx. 150°C for "dehydrating" the surfaces. Then an antireflection system is produced as follows (consisting of four layers in the example):

A) Sputtering of a highly refractive layer with a forward feed of 1.7 m/min, with the carrier oscillating in front of the sputtering source and a layer of 30 nm thickness is deposited during the same! The production of the layer occurs by adding argon and a reactive gas by controlling the reactive gas to a plasma impedance. The process pressure is determined especially by the quantity of argon which leads to typical process pressures in the range of between 1*E-3 and 1^*E-2 mbar. The depositing in the plasma occurs via pulsing.

B) Sputtering of a low-refractive layer with a forward feed of 2.14 m/min. A layer of 30.5 nm thickness is produced in this process. The production of the layer occurs according to the depositing under layer 1. C) Sputtering of a highly refractive layer according to layer 1. A layer of 54 nm thickness is produced here at a forward feed of 0.9 m/min.

D) Sputtering of a low-refractive layer according to layer 2. A layer of 103 nm thickness is produced at a forward feed of 0.63 m/min. Thereafter, the coated substrate is removed with the carrier via a transfer chamber.

E) Production of the antireflection layer with alternative technologies. It is especially preferred when the production method for the antireflection layers is chosen in such a way that the reflection factor R_vis of the individual layers R_{V S} is < 3%.

In the third example an example is given for the production of a pane-like-element 3,7 with a polarizing layer 5,9 between two panes 30, 40 or 50, 60.

In example 3 given below one surface of each pane 30, 40, 50, 60 is coated with a antireflection layer as described before in example 1. The coating with the antireflection layer is on the outer side of the panes when used in a laminate. The coating with a antireflection layer is preferable but not necessary to practice the invention.

Furthermore in order to join the two panes 30, 40, 50, 60 together with the polarizer foil laminated in between in a preferred embodiment interference - or so called bonding layers, preferably of Polyurethan (TPU) are provided on one surface of the pane opposite to the surface with the antireflective coating. The bonding layer of each pane is therefore situated in a laminate on the inner surface of the panes.

The structure of the laminate with a polarizator is as e. g. follows:

Example 3, (structure of a laminated glass element with laminated polarizator): The laminated glass element comprises two single side coated glass sheets of example 1. Each glass sheet has a thickness of 4mm and is laminated in a standard lamination procedure into the following structure: first glass pane with:

anti reflection layer according to example 1

4mm glass sheet

Polyurethane (TPU), interface layer, with a thickness of e. g. 0,38mm, Polarizer foil:

1 sheet of polarizing foil of American Polarizers, Inc., 141 South Seventh Street, Reading, Pennsylvania, USA

Second glass pane with:

Polyurethan layer (TPU) interface layer with a thickness of e. g., 0,38mm 4mm glass sheet

anti reflection layer according to example 1.

After this structure or configuration is established this configuration is then placed into an autoclave and cured for approx. 90min. at temperatures of 85°C at a pressure level of 12bar to laminate the whole stack of a monolithic block without air inclusions.

With the technically and economically relevant antireflection layers it is possible to achieve a contrast, as described above, which is defined as T_vis/Rvis in the range of 10 to 150, preferably 20 to 80, especially 40 to 50 at normal light, with the contrast values being less than 7 in the case of uncoated panes with a polarizing foil. R_Vj_S designates the reflection factor of a layer at standard light D65, T_v,s the

transmission factor. Higher contrast can also be achieved with high-performance methods. However, they do not realize any additional use for the application in practical application. In addition to an arrangement with fixed polarizing foils as shown in Fig. 1 , it is also possible to additionally provide one or both laminates with a polarization- rotating layer. This allows turning the direction of polarization and thus producing a view from one room to be monitored to another room to be monitored. This is shown in detail in Fig. 2a. The same reference numerals as used in Fig. 1 are also used for the same components in Fig. 2a.

Fig. 2a shows further that the second laminate is provided with a fixed polarizer, whereas the first laminate is provided with a polarization-rotating layer 400 on the second pane 40. The polarization of the polarization-rotating layer 400 can be changed by electric triggering. In the present embodiment, without any limitations to the same, the polarization-rotating layer 400 is applied to the antireflection layer 300.2 of the second pane 40. When no voltage is applied to the polarization-rotating layer 400 for example, the polarization directions 70, 80 of the first laminate and the second laminate are orthogonal in relation to one another. A view from one room 100 to a room 200 according to Fig. 2a is not possible, merely a view from room 20 to room 100 and room 20 to room 200.

When an electric voltage is applied, the direction of polarization 70G is rotated thereby, as shown in Fig. 2b. The direction of polarization 70G, 80 are the same for the first and second laminate in an extreme case. A view from room 100 to room 200 is then possible, as shown in Fig. 2b.

It is especially preferred when the polarization-rotating layer is a liquid crystal layer. Such layers are widely used especially in the field of display technology, but are also used in the field of architecture in electrochromic glazing. A glazing with a liquid crystal layer, but without any polarizing layers or polarizing foil, is the LC SmartGlass™ of SmartGlass International Limited. Also in a laminate according to Fig. 2a to Fig. 2b a polymeric bonding material such as a PVB or a EVA-foil between the glass panes for joining them together to the laminate could be used. Fig. 3 shows the influence of the antireflection layer on the reflection and transmission behavior of a pane provided with a polarizer in the wavelength range of 380 nm to 800 nm. The non-polarized light was measured as a lighting source. The number 1000 designates reflection of a glass or plastic which is provided with a polarizing foil without any antireflection coating arranged thereon. As is shown in Fig. 3, the reflection of such a pane lies in the visible wavelength range at approx. 5 to 8% for wavelengths between 380nm and 800nm. When an antireflection layer is applied, the curve 1100 for the reflection is obtained. As is shown in Fig. 3, this measure clearly lowers reflection by 2 to 5% to values up to a maximum of 2% between 420 nm and 680 nm. For the reflection factor R_vjs for standard light D65, a reflection factor R_vis smaller than 1 % is obtained despite reflection of 2% for certain wavelengths. In approximately the same light conditions, a lower reflection 1100 leads to a high contrast, especially under substantially the same illumination conditions in the rooms 20, 100 and 200. In addition to a reduction in reflectivity and thus a resulting increase of the contrast, an increase in transmission is also achieved. This is shown by the transmission curves 1200 for a substrate with polarizing foil and without antireflection layer and 1300 for a substrate with polarizing foil and antireflection layer in the visible wavelength range of 380 nm to 800 nm. The ratio of the (disturbing) reflection R_Vi_S and the transmission T_vis acts as an effective contrast for a spectator at nominally the same light conditions on both sides. In the case of panes without antireflection coating so called uncoated panes, the contrast of R_Vis T_Vi_S is 42%/8% = approx. 7. In the case of a pane with antireflection coating with R_vis < 1%, is achieved., The contrast rises for a system with antireflection coating to more than 47%/1%= approx. 47. This considerable increase in contrast by the antireflection layer has ensured in the layer systems in accordance with the invention that monitoring is considerably more efficient. The contrast ratio which is achieved with the a nti reflection layer typically lies for pane, especially a laminate with a polarizing layer, in the range of 10 to 150, preferably in the range of 20 to 80, especially in the range of 30 to 80. If the first and second pane-like element is provided with antireflection in addition to the polarizing layer, the contrast can be increased considerably over the systems as the state of the art, e.g. JP 2008/008445.

Claims

CLAIMS:

1. A device, comprising

- at least one first pane-like element (3) with at least one first polarizing layer (5);

- at least one second pane-like element (7) with at least one second polarizing layer (9), with a distance being formed between the first pane-like element (3) and the second pane-like element (7),

characterized in that the first and/or the second pane-like element (3, 7) comprises at least one antireflection layer (300.1 , 300.2, 300.3, 300.4).

2. The device according to claim 1 , characterized in that the first and/or the second polarization layer (5, 9) is a first and/or second polarizing foil.

3. The device according to one of the claims 1 to 2, characterized in that the first pane-like element (3) is a first laminate with a first (30) and second pane (40).

4. The device according to claim 3, characterized in that the first polarizing foil is arranged between the first (30) and second pane (40).

5. The device according to one of the claims 1 to 4, characterized in that the second pane-like element (7) is a second laminate with a third (50) and fourth pane (60).

6. The device according to claim 5, characterized in that the second polarizing foil is arranged between the third (50) and fourth pane (60).

7. The device according to one of the claims 3 to 6, characterized in that

the antireflection layer (300.1 , 300.2, 300.3, 300.4) is arranged on one or several of the following surfaces: one outside of the first pane (30) of the first laminate;

one outside of the second pane (40) of the first laminate;

one outside of the third pane (50) of the second laminate;

one outside of the fourth pane (60) of the second laminate.

8. The device according to claim 3, characterized in that the first polarizing foil is arranged on one of the following surfaces:

one outside of the first pane (30) of the first laminate;

one outside of the second pane (40) of the first laminate.

9. The device according to claim 5, characterized in that the second polarizing foil is arranged on one or several of the following surfaces:

one outside of the third pane (50) of the second laminate;

one outside of the fourth pane (60) of the second laminate.

10. The device according to one of the claims 8 to 9, characterized in that the antireflection layer (300.1 , 300.2, 300.3, 300.4) is connected directly or indirectly with one or several of the following surfaces:

one outside of the first pane (30) of the first laminate;

one outside of the second pane (40) of the first laminate;

one outside of the third pane (50) of the second laminate;

one outside of the fourth pane (60) of the second laminate.

11. The device according to one of the claims 3 to 10, characterized in that the first and/or the second pane-like element (3, 7) comprises at least one interface layer.

12. The device according to claim 11 , characterized in that the interface layer is a polymeric bonding layer.

13. The device according to claim 12, characterized in that the bonding layer comprises one or more of the following materials: PVB (Polyvinylbutaryl)

EVA (Ethylenvinylacetat)

TPU (Polyurethan)

Epoxy resins or special gluing systems

14. The device according to one of the claims 1 to 13, characterized in that the first pane-like element (3) and/or the second pane-like element (7) is a single pane, especially a single-pane safety glass.

15. The device according to claim 14, characterized in that the first polarizing layer (5) and/or the second polarizing layer (9) is arranged on one outside of the single pane.

16. The device according to claim 15, characterized in that an antireflection layer (300.1 , 300.2, 300.3, 300.4) is arranged on the first and/or second polarizing layer (5, 9).

17. The device according to one of the claims 1 to 16, characterized in that the device comprises at least one polarization-rotating layer (400).

18. The device according to claim 17, characterized in that the polarization- rotating layer (400) is arranged between the first polarizing layer (5) of the first pane-like element (3) and the second polarizing layer (9) of the second pane-like element (7).

19. The device according to one of the claims 17 to 18, characterized in that the polarization-rotating layer (400) is applied to an antireflection layer (300.1 , 300.2, 300.3, 300.4).

20. The device according to one of the claims 17 to 19, characterized in that the polarization-rotating layer (400) is applied to a pane which lies between the first and second polarizing layer (5, 9).

The device according to one of the claims 17 to 20, characterized in that the polarization-rotating layer (400) is a liquid crystal layer.

The device according to one of the claims 1 to 21 , characterized in that the antireflection layer comprises one of the following structures or is applied with one of the following application methods:

A) the antireflection layer is applied with the help of liquid technology, with the same being applied with the help of liquid technology by using one of the following techniques:

- the antireflection layer is applied with the help of sol-gel technology;

- the antireflection layer is produced as a single interference coating from sol-gel technology;

- the antireflection layer is produced as a multiple interference coating made from sol-gel technology;

- the antireflection layer is produced as a triple interference coating made from sol-gel technology, with the first layer having a refractive index of between 1.6 and 1.8, the second layer a refractive index of between 1.9 and 2.5, and the refractive index of the third layer lies between 1.4 and 1.55;

- the antireflection layer is produced as an interference coating made from sol-gel technology with more than three layers.

B) the antireflection layer is produced with the help of high-vacuum technology, with the layer applied with the help of high-vacuum technology being applied with one of the following techniques:

- the antireflection layer is produced with the help of high-vacuum

technology as a multiple interference layer system;

- the antireflection layer is produced with the help of high-vacuum

technology as a single interference layer system;

- the antireflection layer is produced from a sputtering process under high vacuum; - the antireflection layer is produced from a vacuum metalizing process under high vacuum.

C) the antireflection layer is produced with the help of a CVD process, with the layer applied with the help of a CVD process being applied with the help of one of the following techniques:

- the antireflection layer is produced from an online CVD process;

- the antireflection layer is produced from an offline CVD process;

D) the antireflection layer is produced with the help of an etching process, with the layer applied with the help of an etching process being applied with the help of one of the following techniques:

- the antireflection layer is produced with the help of an etching process as a porous layer;

- the antireflection layer is produced with the help of an etching process as a light-scattering surface;

E) the antireflection layer is produced with the help of an alternative technology.

23. The device according to claim 22, characterized in that the individual layers have low reflectivity values of an individual layer of R_Vi_S < 3%.

24. The device according to one of the claims 1 to 23, characterized in that the first polarizing layer has a first polarizing direction (70) and the second polarizing layer has a second polarizing direction (80).

25. The device according to claim 24, characterized in that the first polarizing direction (70) is essentially orthogonal to the second polarizing direction (80), so that direct light in the visible wavelength region between 380nm and 800nm passing through the device from the first pane-like element (3) to the second pane-like element is (7) is less then 20% preferably less than 10%, most preferable less than 5%, at most preferable less than 2%.

26. The device according to one of the claims 1 to 25, characterized in that the distance being formed between the first pane-like element (3) and the second pane-like element (7) is at least 50cm, preferably at least 1 m, most preferable at least 2m.

27. The device according to one of the claims 1 to 26, characterized in that at least the first and/or the second pane-like element comprises a further coating.

28. The device according to claim 27, characterized in that the further coating is one or more of the following coatings:

- a low-E coating

- a easy to clean coating

- a color effect coating 29. The use of a device according to one of the claims 1 to 28 in one of the following areas:

in the area of architectural glazing, especially in the field of interior design, in security-relevant areas, especially in prisons, in the health field, especially in hospitals and psychiatric institutions.

- in multi functional windows such as fire resistant glazing, radiation shielding glazing, UV shielding glazing, optically switching glazing, coloured glazing or bullet proof glazing.

30. The use of a device according to one of the claims 1 to 28 in one of the following areas:

security related areas and rooms (20), where a single pane like element (7) including a polarizing layer (80) is used to suppress the radiation from a LCD-computer monitor to adjacent areas, in such way, that a first polarization direction of the pane like element (80) is oriented essentially perpendicular to a second polarization direction of the LCD monitor in the visible wavelength region used e.g. in a monitoring room (20).

31. The use of a device according to claim 30,

characterized in that

the transmission of visible light emitted by the LCD monitor through the polarizing layer is suppressed to a level of less than 5%, preferably less than 2% and most preferably to less than 1%.