SAFETY GLASS STACK

Abstract

Adaptive laminated panel element for a vehicle window to reduce the effect of glare of a light source comprising a first panel and a second panel, a liquid crystal layer, and at least one connecting layer for connecting the first panel and the second panel with a spacing with respect to one another, wherein the liquid crystal layer is arranged between the first panel and the second panel or is applied to a surface of one of the first panel or the second panel, and wherein transparency of the adaptive laminated panel element is varied by controlling the liquid crystal layer via electrodes, and wherein the connecting layer is a birefringence-free adhesive layer and the laminated panel element is configured as safety glass for use as a vehicle window.

Claims

1. Adaptive laminated panel element for a vehicle window to reduce the effect of glare of a light source comprising: a first panel and a second panel; a liquid crystal layer; and at least one connecting layer for connecting the first panel and the second panel with a spacing with respect to one another, wherein the liquid crystal layer at least one of is arranged between the first panel and the second panel, or is applied to a surface of one of the first panel or the second panel, and wherein transparency of the adaptive laminated panel element is varied by controlling the liquid crystal layer via electrodes, and wherein the connecting layer is a birefringence-free adhesive layer and the laminated panel element is configured as safety glass for use as a vehicle window.

2. The adaptive laminated panel element according to claim 1, wherein the laminated panel element comprises at least one anti-reflection coating so that the maximum transmission of the laminated panel element is greater than 70%.

3. The adaptive laminated panel element according to claim 1, wherein the liquid crystal layer is provided between the first panel and the second panel, and birefringence-free adhesive layers are used as connecting layers between the liquid crystal layer and the first and second panels.

4. The adaptive laminated panel element according to claim 1, further comprising optical filter layers to reduce the electromagnetic radiation in the ultraviolet spectrum, wherein the filter layers are configured in such a manner that a reduction to less than 1% in the electromagnetic radiation at a wavelength of up to 400 nm is achieved.

5. The adaptive laminated panel element according to claim 1, further comprising optical filter layers to reduce the incident electromagnetic radiation to less than 0.8% at a wavelength of 780 nm to 3000 nm.

6. The adaptive laminated panel element according to claim 1, wherein the liquid crystal layer is divided into segments which each is controlled individually and darkened, and gaps having a width of 20-70 m are present between electrodes of the liquid crystal layer.

7. The adaptive laminated panel element according to claim 6, wherein the spacing of two adjacent segments is less than 70 m.

8. The adaptive laminated panel element according to claim 6, wherein no boundaries are provided between adjacent segments so that a free gap is present between adjacent segments.

9. The adaptive laminated panel element according to claim 1, wherein the liquid crystal material of the liquid crystal layer exhibits a negative dielectric anisotropy and wherein the liquid crystal layer in the switched-off state has a homeotropic alignment.

10. The adaptive laminated panel element according to claim 1, wherein the liquid crystal layer comprises an electrically controllable birefringent nematic liquid display with a gap width of 2-25 m and a phase delay parameter of 0.5 to 0.7 x and a liquid crystal material which shows a negative dielectric anisotropy, wherein a compensation means is provided to compensate for light loss of crossed polarization films and the homeotropic alignment of the liquid crystal layer and wherein the compensation means comprises at least one of a uniaxial negative /2 C plate with a preferred delay in relation to a direction of incidence X or Y of 200-300 nm or a negative biaxial /2 plate with a preferred delay in relation to a direction of incidence Z of 20-150 nm.

11. The adaptive laminated panel element according to claim 1, wherein the liquid crystal layer (LC) comprises a plastic substrate having a thickness of 50 to 300 m and/or wherein the liquid crystal layer comprises a glass substrate with a thickness of 50 to 150 m.

12. The adaptive laminated panel element according to claim 1, wherein the laminated panel element comprises the following components in the given sequence: the first panel of glass, the adhesive film as connecting layer, the polarization filter film, the liquid crystal layer, the polarization filter film/adhesive film as connecting layer, and the second panel of glass.

13. The adaptive laminated panel element according to claim 1, having further comprising at least one index adaptation layer so that the maximum transmission of the laminated panel element is greater than or equal to 70%.

14. The adaptive laminated panel element according to claim 1, further comprising at least one of an optical filter layer, which is a UV thin layer edge filter or a plastic film with worked-in dye and/or comprising an optical filter layer which comprises a UV thin layer edge filter and/or IR thin layer edge filter, or an optical filter layer which comprises a plastic film with integrated or applied reflecting or absorbing material.

15. The adaptive laminated panel element according to claim 1, wherein the laminated panel element comprises two antireflection coatings and at least one antireflection coating contains titanium dioxide and/or silicon dioxide, and wherein an antireflection coating is applied to at least one side of the first panel or the second panel which contains a structure of thin layers of dielectric material with alternately a high refractive index and a low refractive index.

16. A LCD panel for a sunroof with adaptive laminated panel elements according to claim 1, wherein a plurality of laminated panel elements form at least one LCD panel of a sunroof, wherein the laminated panel elements are arranged in such a manner that the preferred viewing angle range is arranged in different quadrants and as a result a multidomain display comes into effect for the occupants of a vehicle.

17. A windscreen having an adaptive laminated panel element according to claim 1, wherein a plurality of segmented liquid crystal layers are provided, which are arranged between the first panel and the second panel and/or are applied to a surface of one of the first panel or the second panel and wherein the segments are arranged along the surface of the windscreen and preferably are arranged in the vertical direction or the horizontal direction.

18. Use of a laminated panel element according to claim 1, as part of a vehicle glazing or a helmet visor, wherein the glazing separates a vehicle interior from the external surroundings of the vehicle.

19. A method for producing an adaptive laminated panel element according to claim 1, comprising the steps: providing the first panel and the second panel, laminating the liquid crystal layer between the first panel and the second panel using at least one connecting layer, sealing the lateral edge regions of the laminated panel element with aid of a sealing material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0068] The disclosure is described hereinafter by means of examples with reference to the appended figures.

[0069] FIG. 1: shows the structure of a conventional safety glass;

[0070] FIG. 2: shows a first structure of the adaptive laminated panel element according to an embodiment of the present disclosure;

[0071] FIG. 3: shows a second structure of the adaptive laminated panel element of according to an embodiment of the present disclosure;

[0072] FIG. 4: shows a third structure of the adaptive laminated panel element according to an embodiment of the present disclosure;

[0073] FIG. 5a: shows the structure of a windscreen using the adaptive laminated panel element according to an embodiment of the present disclosure;

[0074] FIG. 5b: shows a structure of a side window/sunroof using the adaptive laminated panel element according to an embodiment of the present disclosure;

[0075] FIG. 6: shows the spectral transmission range of the adaptive laminated panel element according to an embodiment of the present disclosure;

[0076] FIG. 7a: shows a further advantageous structure of the adaptive laminated panel element according to an embodiment of the present disclosure;

[0077] FIG. 7b: shows the structure of the adaptive laminated panel element with circumferential seal according to an embodiment of the present disclosure;

[0078] FIG. 8: shows a table of a particularly advantageous exemplary embodiment of the laminated panel element according to an embodiment of the present disclosure;

[0079] FIG. 9: shows the structure of a sunroof with four LCD panels according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

[0080] FIG. 1 shows as an example the structure of a conventional safety glass, such as is used, for example, in vehicle building. The safety glass here consists of a first panel S1 which is adhesively bonded to a second panel S2 by means of a connecting layer V.

[0081] FIG. 2 shows a structure of an adaptive laminated panel element according to the present disclosure. According to this first exemplary embodiment, a first panel S1, which preferably includes a glass material, is provided. The first panel S1 has an outer surface which remains free and an inner surface which is in contact with the connecting layer V. Via the connecting layer V it is possible to make a connection between the first panel S1 and the second panel S2 and thereby ensure a spacing between the panels S1 and S2. This structure thus corresponds to the structure of a safety glass. In addition, it is proposed to provide a liquid crystal layer LC on the surface of the second panel S2. In particular, the liquid crystal layer LC is provided on the inner side of the second panel S2.

[0082] The liquid crystal layer LC is preferably an LCD (liquid crystal display) film. The adaptive laminated panel element shown can advantageously be used for the windscreen of a vehicle, wherein particularly preferably the liquid crystal layer is divided into different segments. The liquid crystal layer LC is preferably constructed using an upper substrate and a lower substrate which are facing one another, wherein a liquid crystal material is inserted between these substrates. In a further development an upper polarization layer and a lower polarization layer can be provided on the outer side of the upper substrate and/or the lower substrate. Particularly preferred in addition is a compensating film which is positioned in the upper or in both polarization layers to reduce the dependence of optical properties on the viewing angle, wherein the compensating film in each case compensates for the light loss of crossed polarizers and the elliptical polarization of anisotropic, homeotropically arranged liquid crystals at larger angles of incidence. The compensation scheme follows the concept that the homeotropic liquid crystal layer (uniaxial, positive /2 C plate) is compensated with a uniaxial negative /2 C plate (e.g. COP). The light loss of crossed polarizers can, for example, be compensated with a positive and a negative uniaxial /6 plate or, again for example, with a biaxial /2 delay plate (x-y 220 nm, z 55 nm) (e.g. COP).

[0083] FIG. 3 shows a further advantageous embodiment of the adaptive laminated panel element. Various layers are provided between the first and second panel S1, S2. In particular, the liquid crystal layer LC is provided wherein in each case a connecting layer V1, V2 and an optical filter F1, F2 are provided between the liquid crystal layer LC and the first panel S1 and the second panel S2. The optical filters F1, F2 can be configured as an optical filter layer and in particular as a UV thin layer edge filter and/or IR thin layer edge filter.

[0084] The connecting layers V1, V2 are preferably constructed of at least one of the following materials: PVB, PET, PVC, PU, COP, EVA, or co-PC.

[0085] In the exemplary embodiment of FIG. 3 the liquid crystal layer LC is implemented as a positive phase-change LCD. By using a phase change LCD as a liquid crystal layer LC, it is possible to provide a structure which is particularly suitable for use as a windscreen of a vehicle. Thus, a windscreen for a passenger car or a lorry can particularly preferably be provided.

[0086] The connecting layers V1, V2 are each configured as a birefringence-free adhesive layer so that it is possible to form a laminated panel element which is suitable as safety glass for use as a vehicle window.

[0087] FIG. 4 shows a further advantageous embodiment of the adaptive laminated panel element according to the present disclosure. Optical filter layers F1, F2 are provided between the first panel S1 and the second panel S2. These optical filter layers are configured with the same refractive indices (index matching).

[0088] In addition, connecting layers V1 and V2 are provided which enable a safety glass to be formed. Additional polarization and compensating layers P1 and P2 are provided on the liquid crystal layer LC.

[0089] In this embodiment, the liquid crystal layer LC is configured as a birefringent nematic liquid crystal display so that this structure is particularly suitable for side windows and sun protective glazings.

[0090] FIG. 5a shows a windscreen using an adaptive laminated panel element. This laminated panel element is divided into segments 1L to 4R and thus in the vertical and horizontal directions along the surface of the windscreen. The laminated panel element can however also have more than four segments. The individual segments of the windscreen can be controlled individually or jointly so that selectively different regions of the windscreen can be darkened. The individual segments SEG adjoin one another, wherein invisible gaps G are provided between the segments SEG. In particular, the gaps G are small in such a manner that are not perceivable visually for the human eye. Preferably the width of the gaps G is therefore less than 70 m.

[0091] FIG. 5b shows the segmenting of a side window or sunroof. The adaptive laminated panel element is divided into three segments in this case as an example. The first segment SEG1, the second segment SEG2 and the third segment SEG3 are arranged adjacently, wherein an invisible gap G is provided between these segments. Preferably the structure of the liquid crystal layer LC described according to the exemplary embodiment according to FIG. 4 is used as liquid crystal layer LC.

[0092] FIG. 6 shows the spectral transmission behaviour of the adaptive laminated panel element of the present disclosure. In particular, it can be seen from FIG. 6 that by providing the described optical filter for the infrared and UV range, the electromagnetic radiation up to a wavelength of 400 nm can be reduced to less than 1% and thus like the electromagnetic radiation at a wavelength in the range from 780 nm to 3000 nm can be reduced to <0.8%. The optical filters F1, F2 used in particular include a UV thin film edge filter (sputtered interference filter) or an absorbing substance, e.g. a dye which is worked into a plastic film. The UV filter can additionally be combined with an IR thin film edge filter or, for example, silver or copper can additionally be provided as a reflecting or absorbing material, which is applied to a plastic film or introduced. The two edge filters are used in transmission for the bandpass filter for the visible radiation according to FIG. 6.

[0093] Preferably the refractive indices of the layers used is optimized using Fresnel equations so that a maximum transmission of the safety glass is obtained so that reflection losses can be avoided.

[0094] FIG. 7a shows a structure of a further advantageous embodiment of the present disclosure. The connecting layers V1 and V2 are provided between the first panel S1 and the second panel S2, which directly adjoin the first panel S1 and the second panel S2 and are connected to this. The preferred layer thickness of the first connecting layer V1 and the second connecting layer V2 is 125 m in this case. A polarization layer or an optical filter F1, F2 is provided adjacent to the first connecting layer V1 and the second connecting layer V2. The optical filter F1, F2 additionally has a compensating layer. The compensating layer is integrated in the polarizer and the filters are applied to the polarizer. The compensating layer can be constructed to be reflecting and/or absorbing. The optical filter is connected via an adhesive layer K (or connecting layer) to the liquid crystal layer LC. The liquid crystal layer LC includes two LCD substrate layers 8 which each has electrodes E1, E2 on a surface. The electrodes E1, E2 are connected to a controller via the connecting element VB. A gap is provided between the facing electrodes E1 and E2, in which the liquid crystal material is located and spacers SP which are preferably constructed of plastic.

[0095] As shown in FIG. 7b, for additional sealing against environmental influences and for secure embedding of the liquid crystal element in the panel sandwich, the safety glass sandwich is overmoulded from a relatively soft material (preferably PUR) using a low-pressure (0.2-0.4 MPa) and low-temperature (100-140 C.) plastic injection moulding method so that a circumferential seal U (circumferential seal) can be provided. As a result, the laminated panel element acquires a clean seal, is resistant to environmental influences and can be installed without further measures. The seal embraces the entire region from glass S1 to glass S2 and seals the entire safety glass sandwich. The circumferential seal U is a PUR seal (gasket) which seals the glass sandwich and embeds the liquid crystal element in a floating manner since softer material is brought between the panels S1 and S2 to this end. The LCD seal D on the other hand seals the LCD completely towards the outside.

[0096] The table shown in FIG. 8 includes further details relating to the layer thicknesses and the refractive index and the preferred material of the layers of a particularly advantageous exemplary embodiment (see also FIG. 7).

[0097] FIG. 9 shows the structure of a sunroof with four different LCD panels (I, II, III and IV). Each of these LCD panels can be configured as a laminated panel element wherein these are provided separately or in combination. The best viewing angle range (see arrows in FIG. 9) of the four displays (specific combination of the linear polarization axes and the direction of friction) is designed, for example so that for the vehicle occupants a four-domain configuration of the LCD roof is obtained. That is, the attenuation of the light through the sunroof is as uniform as possible for all the occupants for the most diverse direction of incidence of the sunlight.

[0098] It should be noted that the description and the figures merely set out the principles of the proposed apparatus. On the basis of the present disclosure, it is possible for the person skilled in the art to create various variants of the configurations described. These variants, although not expressly described, are also disclosed by this document and are covered by the claims.