Patent Application
20200230920
The present disclosure relates to an adaptive laminated panel element for a vehicle window or a helmet visor and to a method for producing the adaptive laminated panel element, wherein the laminated panel element includes at least one liquid crystal layer (LCD layer).
Windscreens and sliding roofs as well as side windows and rear windows for vehicles in particular have the function of protecting the occupants of the vehicle and delimiting the interior of the vehicle from the surroundings and at the same time making it possible to see the surroundings from inside of the vehicle. Increasingly being proposed are panels which have tints to modulate the irradiation of light into the vehicle or which have fine leads to enable heating of the panels.
To reduce the incidence of light through a transparent panel into the eyes of persons in the vehicle, various devices such as, for example, sun visors, sun blinds, dark adhesive films for transparent panels, rear windows which can be darkened, tinted window anti-glare lamps etc. are used. However, these devices have disadvantages of an invariable constant light attenuation, a complete darkening of the entire field of view of a transparent window by tinting or complete optical suppression by the dimming means.
The present disclosure addresses the aforesaid disadvantages and describes an adaptive laminated panel element for a vehicle window or a helmet visor by which the glare effect due to light sources can be avoided or reduced.
The object of the present disclosure is to provide an adaptive laminated panel element for a vehicle window or a helmet visor. In particular, it is an object to provide a device for reducing the glare for the occupants or the driver of a vehicle. A further object is in particular also to provide an optimized adaptive device for adjustable reduction of the glare onto the vehicle occupants or a helmet wearer.
An adaptive laminated panel element for a vehicle window or a helmet visor can include a first and a second panel, a liquid crystal layer and at least one connecting layer. The connecting layer can be provided for connecting the first and second panel with a spacing with respect to one another. The liquid crystal layer can be arranged between the first and second panel and/or can be applied to a surface of a first or second panel and preferably glued thereon. The transparency of the adaptive laminated panel element can be varied by controlling the liquid crystal layer via electrodes. As a result of this advantageous adaptive laminated panel element, by using the liquid crystal layer it is possible to provide a panel for a vehicle or a helmet visor which can be darkened by control via electrodes so that the glare effect for the driver or helmet wearer can be accordingly reduced or avoided. The panel can in this case be configured to be flat or in many cases, three-dimensionally curved. The liquid crystal layer can be provided on the inner side of the adaptive laminated panel element and thus attached to an outer surface of the first or second panel. In addition, the liquid crystal layer can be integrated between the first and second panel or preferably laminated therein. The laminated panel element can be configured as a safety glass for use as vehicle window. Safety glass should be understood in particular as a panel structure which meets the requirement in accordance with the ECE Regulation R43: Addendum 42, Revision 3, August 2009, 2012. The adaptive laminated panel element can advantageously also be used for building glazing, aircraft passenger windows, ships and boats.
A further advantage of the present disclosure is the additional sound damping which can be achieved by the adaptive laminated panel element. In particular, the connecting layer together with the liquid crystal layer between the first and second panel allows an additional reduction in sound when the laminated panel element is used, for example, in a vehicle.
The adaptive laminated panel element can be configured as a sunroof of a vehicle to protect the driver from incident light. By means of an electric field, it is possible to lighten or darken parts or the entire area of the adaptive laminated panel element with the liquid crystal layer. The switching times in this case are preferably <1 second and further preferably <0.5 seconds. As a result of these short switching times it is possible to switch the adaptive laminated panel element very rapidly from a state of maximum light transparency to a state of reduced light transparency so that a glare effect can very rapidly be reduced or cancelled out.
Advantageously the liquid crystal layer can be controlled in such a manner that the switching times can be switched continuously in speed. The liquid crystal layer is therefore advantageously configured in such a manner that the switching speed can be adjusted continuously.
In order to control an adaptive laminated panel element for a vehicle window, the apparatus and the method for avoiding or reducing the effect of glare in accordance with DE 10 2011 084 730 A1 can be used. The disclosure content of the document DE 10 2011 084 730 A1 is included in the present application in its full scope.
An adaptive laminated panel element can be provided which has a layer structure with a first and second panel, a liquid crystal layer and at least one connecting layer for connecting the first and second panel with a spacing with respect to one another, wherein the refractive index and the arrangement of the layers and layer thicknesses are configured in such a manner that the regulations in accordance with ECE Regulation R43, Addendum 4.2, Version 3, Aug. 29, 2012 can be fulfilled.
An adaptive laminated panel element can be configured as safety glass for use as a vehicle window. Particularly preferably to this end, the first panel has a thickness in the range of 2.5-3.5 mm, the liquid crystal layer with connecting layer has a thickness in the range of 1-1.5 mm and the second panel has a thickness in the range of 2-3 mm. As a result, the requirements for a safety glass with optimal weight and transmission behaviour can be achieved.
In the present case, vehicles are to be understood in particular as motor vehicles (passenger cars, lorries, coaches) as well as motorcycles and in the wider sense also rail vehicles, water vehicles and aircraft. A further advantage for the use of the adaptive laminated panel element for the glazing of vehicles should be seen in particular in the better control of the air conditioning in the vehicle interior, and the possibility of targeted shading of the vehicle interior.
The adaptive laminated panel element can have an index-adaptation means which enables an almost Fresnel-reflection-free laminated panel element to be provided.
Further preferably, the liquid crystal layer of the adaptive laminated panel element can be configured as a polarization-free, homeotropically aligned structure so that the transmission requirements in accordance with ECE Regulation R43, addendum 4.2, Revision 3, Aug. 29, 2012 can be satisfied. In addition, the liquid crystal layer can be configured as an electrically controllable, birefringent nematic liquid display to enable maximum contrast ratios so that such a laminated panel element can be used in particular as a side window or sunroof of a vehicle.
Advantageously the liquid crystal layer is divided into different segments so that it is possible to darken or lighten only special regions of the laminated panel element so that the glare effects can be reduced in a particularly targeted manner without simultaneously achieving an excessive darkening.
The adaptive laminated panel element can be integrated in a vehicle with a control system in such a manner that an automatic darkening of the laminated panel element is possible.
Advantageously, the laminated panel element can have various coatings wherein by means of a suitable choice of materials, glare protection in the spectral range from 380 to 780 nm can be optimized. In addition, the properties of the laminated panel element for the spectral range from 280 to 400 nm and 780 to 3000 nm can be advantageously modulated by a suitable choice of materials for the coatings. An advantageous coating thus in particular may include a structure and/or a material composition which allows the electromagnetic radiation in the range between 280 to 400 nm and in the range from 780 to 3000 nm to be reduced. To this end, in particular IR filter layers and/or UV filter layers are provided. This results in the further advantage that any heating of the interior of the vehicle can be reduced since specific electromagnetic radiation can be blocked.
The adaptive laminated panel element can have a connecting layer which is a birefringence-free adhesive layer. Due to this advantageous configuration, it is possible to further improve the transmission properties of the laminated panel element so that the maximum transmission of the laminated panel element is preferably >70%. By using the birefringence-free adhesive layer as connection between the first and second panel, it is additionally possible to provide a safety glass for use as a vehicle window. In particular, this safety glass fulfils the requirements of ECE Regulation R43: Addendum 42, Revision 3, Aug. 29, 2012.
Advantageously, the laminated panel element includes at least one anti-reflection coating so that the maximum transmission of the laminated panel element is >70%.
Advantageously, the laminated panel element includes a liquid crystal layer such as an electrically controllable birefringent nematic liquid display with a gap width of preferably 2-25 ∥m and a phase delay parameter of preferably 0.5 to 0.7 xλ and a liquid crystal material which shows a negative dielectric anisotropy, wherein a compensation means is provided to compensate for the light loss of crossed polarization films and the homeotropic alignment of the liquid crystal layer at greater angles of incidence of the light.
The compensation means can in particular at least include a uniaxial negative λ/2 C plate with a preferred delay in relation to the direction of incidence x and/or y (in the x-y plane of the panel element) of 200-300 nm and a negative biaxial λ/2 plate with a preferred delay in relation to the direction of incidence z (along the thickness z of the panel element) of 20-150 nm. The information nm relates here to a distance by which the corresponding direction of incidence of the linear polarization is delayed (x, y) and (z).
The liquid crystal layer between the first and second panel is advantageously provided by means of a birefringence-free adhesive layer as connecting layer between the panels. As a result of this advantageous configuration, the advantageous transmission values of the laminated panel element can be achieved.
The laminated panel element can particularly preferably have optical filter layers to reduce the electromagnetic radiation in the ultraviolet spectrum. Preferably optical filter layers are provided which are configured in such a manner that a reduction in the electromagnetic radiation at a wavelength of up to 400 nm to less than 1% is achieved.
Advantageously, additionally or alternatively to the aforesaid filter layers, further filter layers can be provided to reduce the incident electromagnetic radiation. Advantageously these optical filter layers are adapted in such a manner that the electromagnetic radiation can be reduced to less than 0.8% at a wavelength of 780 nm to 3000 nm.
The adaptive laminated panel element advantageously includes a liquid crystal layer which includes a nematic liquid crystal substance.
The liquid crystal layer can advantageously be switched at least into a first state in which the transparency is maximized and into a second state in which the transparency is minimized so that the laminated panel element can be darkened or lightened. In an advantageous further development it is possible to provide additional states between this first state and the second state which make it possible to provide different gradations of the darkening of the laminated panel element (continuous switching is particularly preferred).
The liquid crystal layer of the laminated panel element is advantageously divided into segments. These segments can each be controlled individually and can be darkened individually. Advantageously gaps having a width of 20 to 60 μm are provided between the electrodes of the liquid crystal layer. As a result of this small gap spacing between the electrodes of the liquid crystal layer, it is possible to improve the optical properties of the laminated panel element and in particular it is possible to make the segmenting of the liquid crystal layer almost invisible to the human eye. Perturbing segment transitions are therefore not discernible.
Advantageously the liquid crystal layer includes different segments wherein the spacing of two adjacent segments is <70 μm. By means of this small spacing it is possible to further increase the optical properties of the laminated panel element.
A gap is provided between two adjacent segments which remains free so that no boundaries are provided between adjacent segments (=boundary-free segment arrangement). As a result of avoiding boundaries between adjacent segments, it is possible to achieve a very small spacing between two adjacent segments so that the optical properties of the laminated panel element can be further improved. In particular, reflections of the segment transitions are avoided.
The laminated panel element can include a liquid crystal layer which is a polarizer-free liquid crystal display layer alternating positive phases having a gap thickness of 2 to 25 μm and a d/p ratio of the LC director of the liquid crystal layer between 0.5 and 2. This particularly advantageous liquid crystal layer enables a further improvement in the transmission properties of the laminated panel element and an optimal control of the laminated panel element with optimized switching times. The spacing of the electrode substrates of the liquid crystal layer is d in this case and the increase of the LC director (liquid crystal director) of the liquid crystal substance is designated by p.
The liquid crystal layer of the laminated panel element can comprise a liquid crystal material which shows a negative dielectric anisotropy and which in the switched-off state (in particular voltage-free state) has a homeotropic alignment. This advantageous configuration enables the optical properties of the laminated panel element to be further optimized and ensure a safe use as vehicle window.
Particularly preferably the liquid crystal layer comprises an electrically controllable birefringent nematic liquid display. This liquid display preferably has a gap width of 2 to 8 μm and a phase delay parameter of 0.5 to 0.7 xλ and a liquid crystal material which shows a negative dielectric anisotropy. Advantageously, compensation means are additionally provided to compensate for the light loss of crossed polarization films and the optically anisotropic homeotropically aligned liquid crystal layer.
Advantageously the liquid crystal layer includes a plastic substrate with a thickness of 50 to 300 μm.
Preferably the liquid crystal layer additionally includes a glass substrate having a thickness of 50 to 150 μm.
An adaptive laminated panel element can advantageously include the following components in the given order: first panel of glass/adhesive film as connecting layer/polarization filter film/liquid crystal layer polarization filter film/adhesive film as connecting layer/second panel of glass. This particularly preferred structure makes it possible to form a laminated panel element which is particularly suitable for safe use as a vehicle window.
An adaptive laminated panel element can advantageously include the following components in the given order: first panel of glass or plastic/adhesive layer of EVA, COP or PU/polarization filter layer of TAC-PVA-TAC/adhesive layer of OCA (OCA=optically clear adhesive)/liquid crystal layer with spacer from a gap thickness of 6 μm/adhesive layer of OCA/polarization filter of TAC-PVA-TAC/adhesive layer of EVA, COP or PU/second panel of glass or plastic. This particularly preferred structure makes it possible to form an adaptive laminated panel element which has optimal optical properties for use in automobile manufacture.
Advantageously the refractive indices of the layers of the laminated panel element are matched to one another in such a manner that the transmission through the laminated panel element is maximized and preferably the maximum transmission of the laminated panel element is 70%. This is achieved in particular by minimizing the reflection losses.
A windscreen can advantageously be constructed using an aforesaid adaptive laminated panel element. Particularly advantageously, the windscreen includes a number of segmented liquid crystal layers 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, wherein the segments are arranged along the surface of the windscreen (along the curved or flat surface of the windscreen), and wherein these segments are preferably arranged in the vertical or horizontal direction along the surface of the windscreen.
Advantageously the above-described adaptive laminated panel element can be used as part of a vehicle glazing, an automobile glazing or a helmet visor.
Further preferably the automobile glazing is a glazing in the vehicle interior, in particular a glazing of separating panels, decorative surfaces or functional surfaces or a glazing which separates a vehicle interior from the outer surroundings of the vehicle, in particular a window or door glazing.
A method for producing the above-described adaptive laminated panel element can include the steps:
The adaptive laminated panel element can advantageously include a coating on the first panel or the second panel, wherein this coating has a refractive index of <⅛ and a layer thickness of <250 μm. Preferably the coating is constructed of a plurality of individual layers.
The adaptive laminated panel element can advantageously include two index matched layers so that by corresponding configuration of these index matched layers, a maximum transmission of the laminated panel element is ≥70%.
The laminated panel element can include optical filter layers, wherein these optical filter layers advantageously include at least one UV thin layer edge filter and/or a plastic film with worked-in dye and/or a UV thin layer edge filter and/or an IR thin layer edge filter.
The optical filter layer can advantageously include a plastic film with an integrated or applied reflecting or absorbing material.
The laminated panel element can advantageously include two antireflection coatings, wherein at least one antireflection coating contains titanium dioxide or silicon dioxide.
The adaptive laminated panel element can advantageously include a first panel and/or a second panel, which is configured as panel safety glass, wherein preferably the first panel and the second panel are transparent to visible light.
The connecting layer can preferably contain at least one of the following materials: PVB (polyvinyl butyral), PET (polyethylene terephthalate), PVC (polyvinyl chloride), PU (polyurethane), COP (cyclic olefin polymer), EVA, co-PC (co-polycarbonate).
The liquid crystal layer can be arranged with the aid of two adhesive films or adhesive materials between the panels, which are glass panels. Alternatively, the panels can also include transparent flexible or non-flexible plastic.
An antireflection coating can be 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 high and low refractive index. As a result of this advantageous configuration, the optical properties of the laminated panel element can be further enhanced.
Advantageously the antireflection layer includes a material of niobium oxide.
Preferably a laminated panel element is proposed which includes layers having as far as possible the same refractive index.
The adaptive laminated panel element can additionally have a heat-insulating layer which can also be used as a sun protective layer in order to achieve a high thermal insulation.
The first panel and the second panel of the adaptive laminated panel element can advantageously include a panel glass, a panel safety glass, partially pre-stressed single-panel glass, laminated safety glass or laminated safety glass with single-panel safety glass.
The aforesaid coatings can preferably be applied by cathode sputtering in vacuum (sputtering technique), by physical vapour deposition, by chemical gas phase deposition, by centrifugal methods or by a dipping method directly onto the first panel and/or the second panel.
The adaptive laminated panel element can comprise more than the first and the second panel and in particular three, four or five panels can be present, preferably including glass and/or plastic.
The connecting layer can preferably be configured as film and in particular as PVB film or EVA film (ethyl vinyl acetate film). Alternatively it is also possible to connect the panels by means of a casting resin.
The liquid crystal layer can be configured as film which contains liquid crystals. Such a film enables the film to be switched from a darkened (crossed polarizers) state into a transparent state or conversely by applying voltages. In this case, the phase transition of the liquid crystals from a transparent strictly ordered structure which makes the film appear dark in transmission into a birefringent phase (the phase is delayed by 180° and thereby turns the linear polarization axis by exactly 90°) which transmits visible light, is switched (or conversely, depending on the liquid crystal mode used). The phase delay (δ) in this case follows the following approximation: δ≢2 π/λ (Δnd) (here λ is the wavelength of the light, d is the gap width and Δn is the difference of the extraordinary (ne) minus the ordinary (nc) refractive index of the liquid crystal medium. The liquid crystal layer can be provided in the laminated panel element in such a manner that only a part of this laminated panel element has the liquid crystal layer so that the entire surface of the laminated panel element does not have the liquid crystal layer. Preferably the liquid crystal layer is merely provided in an edge zone of the laminated panel element and particularly preferably the liquid crystal layer is only present on an area of one third of the total area of the laminated panel element. By means of this configuration, it is possible to provide a laminated panel which has a darkenable region with a liquid crystal layer and in addition, a region without a liquid crystal layer.
An LCD panel for a sunroof (in particular of a vehicle) can particularly advantageously be provided with the described adaptive laminated panel elements. A plurality of laminated panel elements (preferably four) can form at least one (preferably four) LCD panel of a sunroof, wherein the laminated panel elements can be arranged in such a manner that the preferred viewing angle range is arranged in (preferably four) different quadrants and as a result a multidomain display comes into effect for the occupants of a vehicle.
The laminated panel element can preferably have a circumferential seal which seals the region between first and second panel. The layers between the panels can thereby be sealed with respect to the outside. Preferably the circumferential seal is a PUR seal (polyurethane) which seals the laminated panel element (glass sandwich) and floatingly embeds the liquid crystal element (or liquid crystal layer). The particularly advantageous floating embedding can be achieved by using a soft material (such as preferably PUR) for the circumferential seal.
A method for producing the laminated panel element advantageously comprises a low-pressure/low-temperature plastic injection moulding method, in particular for applying the circumferential seal. Advantageously a tool (steel tool) is built around the panels which has several injection nozzles on the circumference. A low-melting plastic (preferably about 100-150° C. can then be injected at low pressure (preferably about 0.2-0.4 MPa as a seal between the first and second panel. The panel thus acquires a clean seal, is resistant to environmental influences and can be installed without further measures.
By means of the described configurations of the laminated panel element, it is additionally possible to achieve the advantageous transmission values of the entire laminated panel element of >70%.
It should be pointed out that the described features can be used alone and in combination with one another insofar as this is deduced in particular for the person skilled in the art. In particular, all the features described in this document can be combined with one another in any way. This applies particularly to the features set out in the claims.
The disclosure is described hereinafter by means of examples with reference to the appended figures.
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 λ/2 C plate) is compensated with a uniaxial negative λ/2 C plate (e.g. COP). The light loss of crossed polarizers can, for example, be compensated with a positive and a negative uniaxial λ/6 plate or, again for example, with a biaxial λ/2 delay plate (x-y 220 nm, z 55 nm) (e.g. COP).
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.
In the exemplary embodiment of
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.
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.
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.
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.
As shown in
The table shown in
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2017 203 627.3 | Mar 2017 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2018/055513 | 3/6/2018 | WO | 00 |
