IR transparent pane

Abstract

The present invention relates to an infrared-transparent pane comprising an infrared-transparent substrate and an infrared-transparent coating, and to optical devices comprising said pane, and to uses of said pane.

Description

[Technical field]

[0001] The present invention relates to an infrared-transparent pane comprising an infrared-transparent substrate and an infrared-transparent coating, and to optical devices comprising said pane, and to uses of said pane. [Background technology]

[0002] Infrared waves, or infrared radiation, have many sources and uses. Typical infrared radiation originates from the sun at wavelengths beyond the visible range, i.e., greater than 780 nm (near infrared) and up to 3 mm (far infrared).

[0003] Infrared light is utilized in a variety of applications ranging from the detection of infrared (IR) signals in, for example, thermal imaging, to elemental identification in IR spectroscopy. A range of substrates are used to manufacture optical elements that transmit, reflect, and / or generally control the trajectory of IR light, such as planar optics (i.e. windows, mirrors, polarizers, beam splitters, prisms), spherical lenses (i.e. plano-concave / plano-convex, biconcave / biconvex, meniscus), aspheric lenses (parabolic, hyperbolic, compound), achromatic lenses, and lens devices (i.e. imaging lenses, beam expanders, eyepieces, objective lenses). The bulk materials of these substrates for infrared applications vary in their physical properties, particularly their optical properties. As a result, knowing the advantages of each property allows the selection of the appropriate material for any IR application. Since infrared light is composed of longer wavelengths than visible light, the two wavelength regions, visible and infrared, behave differently when propagating through the same optical medium. In general, certain materials, notably fused silica, borosilicate glass, sapphire, alumina-silicate glass, and certain soda-lime glasses, can be used for both IR and visible applications, while others are used exclusively for one or the other application. The most important attribute that defines any bulk material for infrared light is its infrared light transmittance. Transmittance is a measure of throughput and is expressed as a percentage of the incident light.

[0004] Certain optical elements can be used to transmit infrared light between the light source and / or receptor. Examples of such optical elements include cover glasses and optical elements used with infrared light, such as lenses, prisms, or mirrors.

[0005] Currently, self-propelled vehicles are being fitted with an increasing number of photoreceptors and optical elements, particularly those with operating wavelength ranges in the infrared, for example 800-2000 nm, sometimes called "near infrared" because of its closeness to the visible light spectrum in the range of 350-780 nm. Self-propelled vehicles include cars, vans, lorries, motorbikes, buses, trams, trains, drones, planes, helicopters, etc.

[0006] The International Publication No. 2018015312A1 brochure describes: (i) a 5m -1 The present invention relates to an automotive glazing comprising at least one glass sheet having an absorption coefficient of less than 100 nm, the glass sheet having an outer surface and an inner surface, and (ii) an infrared filter. On the inner surface of the glass sheet in a zone free of the infrared filter layer, a remote measurement device based on infrared light in the wavelength range of 750-1050 nm is disposed. Such a device is not resistant to the external environment and therefore needs to be protected from the external environment behind a glass sheet such as a windshield.

[0007] A particular example of such an optical element is the cover of an infrared receptor, such as an infrared camera or lidar, which is used especially in the automotive field. In fact, the receptor is typically placed behind a cover to protect it from the external environment. The detection limit of the receptor is obviously related to the transmission level of the cover in the operating wavelength range of the receptor.

[0008] Therefore, there is a need to increase the transmission level of the cover in the infrared wavelength range. Such increased transmission can typically be achieved using an anti-reflective coating that includes alternating layers of low and high refractive index materials, thereby reducing the reflection of incident light at the cover surface. Such multi-layer coatings can typically increase the infrared light transmitted through the coated substrate, improving contrast and eliminating ghost images, thereby improving the efficiency of the optical element.

[0009] Chinese Patent No. 110218006B relates to a laminated glass for vehicles that can be adapted to use laser radar or near infrared camera. This laminated glass contains an anti-reflection film, in particular to reduce the energy loss of near infrared light of the laser or near infrared camera. The working wavelength of such an anti-reflection coating is narrow, and therefore it is not useful in various applications. Moreover, such laminated glass is not resistant to the external environment.

[0010] Multi-layer coatings are effective at reducing IR reflectance, but are generally less durable than the substrate itself. Thus, typically, anti-reflective coatings are placed on the inner surface of the cover, meaning on the surface of the cover that faces the infrared receptor (while the outer surface faces the exterior environment).

[0011] The durability of anti-reflective coatings has not been sufficient to date to be placed on the outer surface of the cover, such as to maintain optical performance during the life of the product. Furthermore, to the extent that anti-reflective coatings are placed on the inner surface of the cover, the color of reflection in the visible range (having wavelengths of 350 to 780 nm) has not necessarily been optimized.

[0012] In particular, it is difficult to obtain an anti-reflective coating for infrared radiation, especially near infrared light in the range between 800-2000 nm, while maintaining low visible light reflectance and / or a near achromatic color of reflected light.

[0013] Thus, there remains a need for anti-reflective coatings that have improved durability, resistance to both physical and environmental damage, and / or neutral color rendering, and / or low light reflectance. Summary of the Invention

[0014] The present invention provides an infrared-transparent pane comprising a first infrared-transparent substrate having a first surface and a second surface opposite the first surface, and an infrared anti-reflective coating on the first surface, the coating comprises an array of S lamellae; - each arrangement includes a layer of high refractive index material beneath a layer of low refractive index material; - S≧2; The wavelength λ of the top layer of the coating having a low refractive index material IR Optical thickness e at UL but, (λ IR *0.12)≦e UL ≦(λ IR *0.40) is in the range where λ IR provides an infrared-transparent pane characterized by an infrared wavelength selected within the range of 800 to 2000 nm.

[0015] The invention further provides an optical device for infrared light in the range of 800 to 2000 nm comprising an infrared-transparent pane as described above and at least one of an infrared-sensitive receptor or an infrared light source, the pane being configured to transmit infrared light to the receptor and / or from the light source.

[0016] Finally, there is provided the use of said infrared transparent pane in a lidar. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The present invention provides an infrared-transparent pane comprising a first infrared-transparent substrate having a first surface and a second surface opposite the first surface, and an infrared anti-reflective coating on the first surface, the coating comprises an array of S lamellae; - each arrangement includes a layer of high refractive index material beneath a layer of low refractive index material; - S≧2; The wavelength λ of the top layer of the coating having a low refractive index material IR Optical thickness e at UL but, (λ IR *0.12)≦e UL ≦(λ IR *0.40) λ IR provides an infrared-transparent pane characterized by an infrared wavelength selected within the range of 800 to 2000 nm.

[0018] Infrared wavelengths typically range from 800 nm to over 10 micrometers. However, the use of infrared technology typically focuses on near-infrared wavelengths, the range of wavelengths closest to the visible red boundary, i.e., λ IR The treatment is carried out in the range of 800 to 2000 nm, which is the operating wavelength range considered in the present invention, also referred to as .lambda..

[0019] Within the scope of the present invention, the terms "infrared", "infrared light" and "infrared wavelengths" can be used synonymously and include the same wavelength range of 800-2000 nm, i.e., the present infrared anti-reflective coating has an operating wavelength in the infrared range of 800-2000 nm.

[0020] Within the present invention, the terms "alternative" and "preferably" may be used interchangeably.

[0021] Within the scope of the present invention, for example, λ IR is the selected operating infrared wavelength selected within the range of 800-2000 nm. That is, λ IR is a precise value selected within the range of 800 to 2000 nm and is therefore not an average value of the wavelength values ​​within said range.

[0022] Within the scope of the present invention, the operating wavelengths in the infrared region may in particular be 850 nm, 905 nm, 940 nm, 1064 nm, 1310 nm, 1350 nm, 1550 nm, 1650 nm. These operating wavelengths are determined by the optical device that utilizes the present infrared-transparent pane. For LiDAR in automotive applications, for example, the operating wavelength may in particular be 905 nm, or 1550 nm. An acceptable difference of 25 nm around the nominal value of the wavelength may be taken into account, for example a wavelength range of 1525 to 1575 nm around the nominal value of 1550 nm may be accepted.

[0023] The infrared-transmitting substrate is specifically selected to optimize the transmission of infrared radiation. The substrate can be selected from glass, polymethylmethacrylate (PMMA), polycarbonate (PC), polyvinyl chloride (PVC), polyethylene (PE), polybutylene (PB), or mixtures and composites of two or more of polymethylmethacrylate (PMMA), polycarbonate (PC), polyvinyl chloride (PVC), polyethylene (PE), polybutylene (PB). The preferred substrate is glass.

[0024] The infrared transparent substrate may have a thickness range of from 0.5 mm to about 15 mm, alternatively from 1 mm to about 10 mm, alternatively from 1 mm to about 8 mm, alternatively from 1 mm to about 6 mm, alternatively from 0.5 to 4 mm.

[0025] In the case of glass, the glass may be a silica-based glass, for example a soda-lime-silica, aluminosilicate, or borosilicate type glass.

[0026] The preferred glass type is referred to herein as "infrared transmitting glass" and typically has a transmittance of 15 nm in the wavelength range of 750 to 1650 nm. -1 Less than or 5m -1 To quantify the low absorption of glass sheets in the infrared range, the absorption coefficient in the wavelength range of 750 to 1650 nm is used in the description herein.

[0027] Thus, a preferred substrate may be selected from infrared-transmitting glass due to its resistance to long-term exposure, color stability, and low environmental impact with respect to use and recycling.An additional advantage of glass is that the thickness of the glass sheet can be adjusted to reduce the overall weight of the pane.

[0028] The absorption coefficient is defined as the ratio between the absorbance in a particular environment and the optical path length traversed by electromagnetic radiation. This is m -1 It is expressed in units of 1 / 2, which is independent of the thickness of the material, but is a function of the wavelength of the absorbed radiation and the chemical nature of the material.

[0029] The absorption coefficient (μ) at a selected wavelength λ can be calculated from measurements of the transmittance (T) and refractive index n of a material (thickness), where n, ρ, and T are functions of the selected wavelength λ: TIFF2024528561000001.tif18170, where ρ=(n-1) 2 / (n+1) 2 It is.

[0030] The type of glass sheet according to the invention preferably has an absorption coefficient <15m in the wavelength range from 750 to 1650 nm. -1 Such glass types are commonly used for optical techniques with operating wavelengths in the infrared range of 800-2000 nm, because their low absorption coefficient offers the added advantage that the final IR transmittance is less affected by the light path through the material. Preferably, the glass sheets are 5 mm thick. -1 Less than or 3m -1 Less than or even 2m -1 Such glass types are sometimes called "ultra-clear" glasses.

[0031] In some cases, the glass may be tinted glass, such as green, blue, or gray to black glass, provided that the glass is transparent to infrared radiation from 800 to 2000 nm. For example, in lidar applications, the glass substrate may be infrared-transparent gray glass or infrared-transparent black glass.

[0032] Conventional "transparent glass" typically has an absorption coefficient of about 30m -1 about the same order of magnitude as the presently preferred glass type.

[0033] As discussed above, the absorption coefficient is <15m in the wavelength range of 750-1650 nm. -1 , or 5m -1 Glasses of different compositions may be suitable within the scope of the present invention.

[0034] The base glass composition of the present invention, expressed in terms of glass weight percentages, is: SiO255~85% Al2O30-30% B2O30~20% Na2O 0~25% CaO 0~20% MgO 0~15% K2O 0~20% BaO 0~20% The total content of the composition may be

[0035] Alternatively, the base glass composition, expressed in terms of glass weight percentages, is: SiO255~78% Al2O30-18% B2O30-18% Na2O 0~20% CaO 0~15% MgO 0~10% K2O 0~10% BaO 0~5% The total content of the composition may be

[0036] Alternatively, the base glass composition, expressed in terms of glass weight percentages, is: SiO260~75% Al2O30-6% B2O30-4% CaO 0~15% MgO 0~10% Na2O 5~20% K2O 0~10% BaO 0~5% The total content of the composition may be

[0037] In addition to its basic composition, the glass can contain other components depending on the desired effect. Within the scope of the present invention, glasses that are very transparent in the high infrared (IR) with weak or no effect on their aesthetics or their color can be obtained by combining low amounts of iron with chromium within certain content ranges in the glass composition.

[0038] Thus, the glass sheet composition may comprise the following contents, expressed as percentages of the total weight of glass: - total Fe (expressed as Fe2O3) in an amount between 0.002 and 0.06%, and Cr2O3 in an amount between 0.0001 and 0.06%; or - total Fe (expressed as Fe2O3) in an amount between 0.002 and 0.06%, and Cr2O3 in an amount between 0.0015 and 1%, and Co in an amount between 0.0001 and 1%; or - total Fe (expressed as Fe2O3) in an amount between 0.02 and 1%, and Cr2O3 in an amount between 0.002 and 0.5%, and Co in an amount between 0.0001 and 0.5%; or - total Fe (expressed as Fe2O3) in an amount between 0.002 and 1%, and Cr2O3 in an amount between 0.001 and 0.5%, and Co in an amount between 0.0001 and 0.5%, and Se in an amount between 0.0003 and 0.5%; or - total Fe (expressed as Fe2O3) in an amount between 0.002 and 0.06%, and CeO2 in an amount between 0.001 and 1%; or - Total Fe (expressed as Fe2O3) in an amount between 0.002 and 0.06%; and - manganese (calculated as MnO) in an amount ranging from 0.01 to 1% by weight; - antimony (expressed as Sb2O3) in an amount ranging from 0.01 to 1% by weight; - arsenic (expressed as As2O3) in an amount ranging from 0.01 to 1% by weight, or - Copper (expressed as CuO) in an amount ranging from 0.0002 to 0.1% by weight One of.

[0039] These types of glasses that have high transmission in the infrared are well known to those skilled in the art and need not be described further herein. -1 , or 5m -1 There may be alternatives that are less than this and may be suitable within the scope of the present invention.

[0040] The glass may be annealed, tempered, bent, or heat strengthened glass.

[0041] A typical heat treatment involves heating the glazing in air to a temperature of at least 560°C, for example between 560°C and 700°C, in particular about 640°C to 670°C, for a period of about 3, 4, 6, 8, 10, 12 or even 15 minutes, depending on the type of heat treatment and the thickness of the glazing. The treatment can include a quenching step after the heating step in order to introduce a stress difference between the surface and the center of the glass, whereby in case of impact the so-called tempered glass sheet breaks safely into small fragments.

[0042] The glass may be flat or may be fully or partially curved to precisely fit a particular design or shape required by the end use application. The techniques for bending and / or curving are well known and will not be described further herein.

[0043] A substrate typically has two opposing surfaces: a first surface and a second surface opposite the first surface.

[0044] An infrared anti-reflective coating is present on the first surface.

[0045] Within the scope of the present invention, a thin film means a layer of material having a geometric thickness of 0.5 to 900 nm, or 0.5 to 800 nm, or 0.5 to 700 nm, or 0.5 to 500 nm.

[0046] Such thin films can typically be formed using chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD), magnetron sputtering, and the like.

[0047] Within the scope of the present invention, the terms "below", "underneath" and "under" indicate the relative position of a layer with respect to the next layer opposite in a layer sequence starting from a substrate. Within the scope of the present invention, the terms "above", "upper", "on top" and "on" indicate the relative position of a layer with respect to the next layer opposite in a layer sequence starting from a substrate.

[0048] Within the scope of the present invention, the infrared anti-reflection coating comprises S sequences of thin layers, one of which comprises a layer of high refractive index material beneath a layer of low refractive index material. To ensure the optimization of the optical path, it may be advisable to ensure contact between the high refractive index material beneath the layer of low refractive index material in the sequence. These sequences are then laminated together, so that the coating comprises alternating high and low refractive index layers. To allow for further optimization of the optical path, the sequences may be in contact with each other. Typically, each layer has a geometric thickness of <900 nm, alternatively <800 nm, alternatively <700 nm.

[0049] Within the scope of the present invention, there are at least two sequences in the antireflective coating. Typically, there may be two, three, four, five, or more sequences. In this specification, when an antireflective coating is defined by the number # of sequences, it is not intended to mean that there can be considered to be more sequences beyond the # number of sequences defined. Thus, the top sequence of an antireflective coating is also the last sequence of said coating. Suitable antireflective coatings that work in the infrared range of 800-2000 nm are designed to have two, three, four, or more sequences as described above, and can be processed at reasonable manufacturing costs with the advantage of realizing performance to reduce reflection.

[0050] Thus, within the scope of the present invention, the topmost sequence comprising a layer of high refractive index material immediately below a layer of low refractive index material is also the final sequence of the antireflective coating furthest upward from the substrate, i.e., the topmost layer of low refractive index material is also the final layer of the antireflective coating in contact with the environment.

[0051] Similarly, the bottommost sequence, which includes a layer of high refractive index material directly beneath a layer of low refractive index material, is also the first sequence of the antireflective coating closest upward from the substrate.

[0052] Within the scope of the present invention, it has been found that anti-reflective coatings containing two or three sequences have high infrared transmittance but are not optimally designed for their color neutrality or for low light reflectance in the visible range.

[0053] Within the scope of the present invention, it has been found that anti-reflective coatings containing four or more sequences are optimally designed for low optical reflectance (Rc≦11%) due to their color neutrality in the visible range with high infrared transmittance.

[0054] Within the scope of the present invention, a layer can include one or more sublayers. If a layer is considered to be a low refractive index layer, it can include sublayers each having a low refractive index. If a layer is considered to be a high refractive index layer, it can include sublayers each having a high refractive index.

[0055] Within the scope of the present invention, a high refractive index material has a refractive index at a wavelength of 550 nm of ≧1.8, or ≧1.9, or ≧2.0.

[0056] Within the scope of the present invention, a low refractive index material has a refractive index at a wavelength of 550 nm of ≦1.7, or alternatively ≦1.6.

[0057] The refractive index of the high refractive index material at a wavelength of 550 nm is higher than that of the low refractive index material. The refractive indices of the high and low refractive index materials may differ by a value of at least 0.1, preferably by a value of at least 0.2, more preferably by a value of at least 0.25. Such a refractive index difference allows for an optimal material interface and therefore optimal transmission of infrared light.

[0058] However, when calculating the optical thickness at infrared wavelengths in the range of 800-2000 nm, the refractive index of the material measured in said infrared wavelength region is used. The refractive index is available in common tools available in the field of thin films and may not be listed here for each material. Sources of information include CODE software from WTheiss Hardware and Software, which is used for thin film analysis and design and also for optical thin film design.

[0059] Independently of the number of sequences, the antireflective coating may have a base layer in contact with the substrate and also in contact with the bottommost layer having a high refractive index, the bottommost layer having a high refractive index. The optional base layer typically does not contribute to the infrared antireflective properties of the antireflective coating. Such an optional base layer may be provided to ensure adhesion of the coating to the substrate and / or to prevent ion migration from the substrate that may degrade the overlying coating, such as may occur with glass substrates. The optional base layer may have any refractive index and does not optically contribute to the antireflective effect of the coating. That is, the base layer does not play a part of the antireflective function of the antireflective coating and is not part of the optical layer design. Preferably, the optional base layer may have a refractive index similar to that of the substrate, i.e., a refractive index within a value of 0.3 compared to that of the substrate.

[0060] An example of the base layer is silicon oxide.

[0061] When the infrared anti-reflective coating of the present invention comprises two sequences, i.e., S=2, the first layer having a high refractive index may be referred to as layer HA, the first layer of low refractive index on the HA layer may be referred to as layer LA, the second layer having a high refractive index on the LA layer may be referred to as layer HB, and the second layer of low refractive index on the HB layer may be referred to as layer LB. Base material / HA / LA / HB / LB or Substrate / Base layer / HA / LA / HB / LB.

[0062] For S=2, the second layer LB of low index layers may be referred to as the uppermost (and final) layer UL having a low index, and the second layer HB of high index layers may be referred to as the uppermost layer UH having a high index. Similarly, the first layer LA of low index layers may be referred to as the lowermost layer having a low index, and the first layer HA of high index layers may be referred to as the lowermost layer having a high index.

[0063] When the infrared anti-reflective coating of the present invention comprises a triplet arrangement, i.e. S=3, the first layer having a high refractive index may be referred to as layer HA, the first layer of low refractive index on the HA layer may be referred to as layer LA, the second layer of high refractive index on the LA may be referred to as layer HB, the second layer of low refractive index on the HB layer may be referred to as layer LB, the third layer of high refractive index on the LB may be referred to as layer HC, and the third layer of low refractive index on the HC layer may be referred to as layer LC: Base material / HA / LA / HB / LB / HC / LC or Substrate / Base layer / HA / LA / HB / LB / HC / LC.

[0064] For S=3, the third layer of low index layers LC may be referred to as the uppermost (and final) layer UL having a low index, and the third layer of high index layers HC may be referred to as the uppermost layer UH having a high index. Again, the first layer of low index layers LA may be referred to as the bottom layer having a low index, and the first layer of high index layers HA may be referred to as the bottom layer having a high index.

[0065] When the infrared anti-reflective coating comprises four sequences, i.e., S=4, a first layer having a high refractive index may be referred to as layer HA, a first layer of low refractive index on the HA layer may be referred to as layer LA, a second layer of high refractive index on the LA may be referred to as layer HB, a second layer of low refractive index on the HB layer may be referred to as layer LB, a third layer of high refractive index on the LB may be referred to as layer HC, a third layer of low refractive index on the HC layer may be referred to as layer LC, a fourth layer of high refractive index on the LC may be referred to as layer HD, and a fourth layer of low refractive index on the HD layer may be referred to as layer LD: Base material / HA / LA / HB / LB / HC / LC / HD / LD or Substrate / Base layer / HA / LA / HB / LB / HC / LC / HD / LD.

[0066] For S=4, the fourth layer LD of low index layers may be referred to as the uppermost (and final) layer UL having a low index, and the fourth layer HD of high index layers may be referred to as the uppermost layer UH having a high index. Again, the first layer LA of low index layers may be referred to as the lowermost layer having a low index, and the first layer HA of high index layers may be referred to as the lowermost layer having a high index.

[0067] When the infrared anti-reflective coating comprises a 5-sequence, i.e., S=5, a first layer having a high refractive index may be referred to as layer HA, a first layer of low refractive index on the HA layer may be referred to as layer LA, a second layer having a high refractive index on the LA may be referred to as layer HB, a second layer of low refractive index on the HB layer may be referred to as layer LB, a third layer having a high refractive index on the LB may be referred to as layer HC, a third layer of low refractive index on the HC layer may be referred to as layer LC, a fourth layer having a high refractive index on the LC may be referred to as layer HD, a fourth layer of low refractive index on the HD layer may be referred to as layer LD, a fifth layer having a high refractive index on the LD may be referred to as layer HE, and a fifth layer of low refractive index on the HE layer may be referred to as layer LE: Base material / HA / LA / HB / LB / HC / LC / HD / LD / HE / LE or Substrate / Base layer / HA / LA / HB / LB / HC / LC / HD / LD / HE / LE.

[0068] For S=5, the fifth layer LE of low index layers may be referred to as the uppermost (and final) layer UL having a low index, and the fifth layer HE of high index layers may be referred to as the uppermost layer UH having a high index. Again, the first layer LA of low index layers may be referred to as the lowermost layer having a low index, and the first layer HA of high index layers may be referred to as the lowermost layer having a high index.

[0069] For S>5, sequences follow a similar nomenclature.

[0070] If S ≥ 2, the optical thickness e of the top layer with a low refractive index of the infrared anti-reflection coating UL is (λ IR *0.12)≦e UL ≦(λ IR *0.40), where λ IR is an infrared wavelength selected within the range of 800 to 2000 nm.

[0071] Such an optical thickness of the top layer with a low refractive index allows for adequate anti-reflection effect at infrared wavelengths. IR *0.12) or >(λ IR *0.40), the incident infrared radiation will be reflected on the surface and the optimum level of performance of the anti-reflective coating will not be ensured and / or the color of the reflection will be inappropriate from the point of view of an external observer.

[0072] That is, when the operating wavelength in the infrared region is selected from among 850 nm, 905 nm, 940 nm, 1064 nm, 1310 nm, 1350 nm, 1550 nm, and 1650 nm, the optical thickness e of the top layer having a low refractive index UL is calculated using the selected operating wavelength. For example, at an operating wavelength of 905 nm, the optical thickness e UL can be in the range of 108.6 to 362 nm; or at an operating wavelength of 1550 nm, the optical thickness e UL can be in the range of 186 to 620 nm.

[0073] In another embodiment consistent with this embodiment, when S≧2, the sum of the optical thicknesses of the layers of the high refractive index material of the infrared anti-reflection coating, Σe H is (λ IR *0.10)≦Σe H ≦(λ IR *0.55).

[0074] That is, when S=2 or 3, the sum of the optical thicknesses of the layers of high refractive index material, Σe H e HA +e HB (+eHC ) is (λ IR *0.10)≦Σe H ≦(λ IR *0.55) or (λ IR *0.28)≦Σe H ≦(λ IR *0.55) or (λ IR *0.35)≦Σe H ≦(λ IR *0.50) or (λ IR *0.38)≦Σe H ≦(λ IR *0.47).

[0075] That is, when S=4 or more, or especially when S=4, the sum of the optical thicknesses of the layers of high refractive index material Σe H is (λ IR *0.10)≦Σe H ≦(λ IR *0.55) or (λ IR *0.10)≦Σe H ≦(λ IR *0.45) or (λ IR *0.10)≦Σe H ≦(λ IR *0.35). For S=4, Σe H =e HA +e HB +e HC +e HD +e HE And so on, for S>4.

[0076] This provides the added advantage that either coatings containing two or three sequences, or coatings containing four or more sequences, may further improve infrared transmission over a wide operating range in the wavelength region, possibly including a first particular operating wavelength. In these cases, an anti-reflective coating designed for one first particular operating wavelength may actually be suitable for a second or further particular operating wavelength. This provides a variety of design possibilities but limited manufacturing variations, since one anti-reflective coating can serve multiple purposes.

[0077] When S=2 or 3, the sum of the optical thicknesses of the layers having the low refractive index, Σe L to the visible wavelength of 550 nm, Σe L / 550nm” is the selected infrared operating wavelength (λ IR ), in percentage terms, using the following formula: (0.0614×λ IR )-K1≦Σe L / 550nm≦(0.0614×λ IR )-K2 in accordance with Here, K1=25% and K2=-3%.

[0078] This ratio "Σe L / 550 nm" has been found to ensure the optimum infrared anti-reflection effect of the infrared anti-reflection coating having S=2 or 3.

[0079] Alternatively, K1 may be 22%, or 19%. Alternatively, K2 may be 1%.

[0080] In a compatible embodiment, when S=2 or 3, the optical thickness e of the upper (or final) layer UL, layer LB, or LC having a low refractive index of the infrared anti-reflection coating is UL is (λ IR *0.15)≦e UL ≦(λ IR *0.33), preferably (λ IR *0.20)≦e UL ≦(λ IR *0.32), or (λ IR *0.22)≦e UL ≦(λ IR *0.29), or (λ IR *0.24)≦e UL ≦(λ IR *0.27), and / or Optical thickness e of the top layer UH with high refractive index of the infrared anti-reflection coating UH is (λ IR *0.25)≦e UH ≦(λIR *0.50), preferably (λ IR *0.31)≦e UH ≦(λ IR *0.42), and / or The optical thickness e of the lower (or first) layer LA having a low refractive index of the infrared anti-reflection coating LA e LA ≦(λ IR *0.13), preferably (λ IR *0.04)≦e LA ≦(λ IR *0.07), and / or the optical thickness e of the lower (or first) layer HA having a high refractive index of the infrared anti-reflection coating; HA e HA ≦(λ IR *0.15), preferably (λ IR *0.02)≦e HA ≦(λ IR *0.11), more preferably (λ IR *0.03)≦e HA ≦(λ IR *0.10).

[0081] For S=2 or 3, or especially for S=2, where one or more of the above properties are obtained, an optimal anti-reflective coating can be obtained using a simple coating, which is cost-effective and can be obtained by standard thin film deposition methods.

[0082] These independent variations in the various layers can be optimized within the ranges that operate at different wavelengths of the infrared, resulting in an anti-reflective coating that can function adequately at a first selected operating infrared wavelength and over a broader range of a second operating infrared wavelength.

[0083] In an embodiment according to the invention, when S≧4, the optical thickness e′ of the layer can be considered using the refractive index of the material at a wavelength of 550 nm, while the optical thickness e is considered at an infrared wavelength selected in the range of 800-2000 nm. In fact, it has been found that in the case of an anti-reflective coating with four or more arrangements, it is advantageous to consider the optical thickness e′ of the layer in the visible range, since it has been found that an anti-reflective coating for infrared wavelengths is obtained that has an achromatic color in the reflection in the visible. That is to say, the anti-reflective coating is optimized for maximum transmission of infrared radiation from 800 to 2000 nm, while it has an achromatic color from the point of view of an external observer (on the side of the reflective coating) at visible wavelengths from 350 to 780 nm, and shows low light reflection.

[0084] Within the scope of the present invention, the achromatic color of reflection is -4° at visible wavelengths of 350-780 nm and angles of incidence of 0-60°. * <1 and -5 * <1 is achieved when the coating side is neutral in reflection (CIELAB values ​​under illuminant D65).

[0085] The color is also angularly stable, i.e., Δa * and Δb * is <5.

[0086] Within the scope of the present invention, low optical reflectance on the coating side is considered if Rc≦11%.

[0087] Therefore, if S≧4, the optical thickness e′ of the top layer UH having a high refractive index of the infrared anti-reflection coating UH can be in the range of 15 to 110 nm, preferably 15 to 105 nm, and more preferably 20 to 100 nm.

[0088] If S ≥ 4, the optical thickness e of the top layer UL having a low refractive index of the infrared anti-reflection coating UL Also, (λ IR *0.12)≦e UL ≦(λ IR ​​*0.40), preferably (λ IR *0.15)≦e UL ≦(λ IR *0.37), more preferably (λ IR *0.19)≦e UL ≦(λ IR *0.33). Such additional parameters further improve the color neutrality and the angular stability of the achromatic colors.

[0089] For S=4, the sum of the optical thicknesses of the layers of high refractive index material is Σe H (=e HA +e HB +e HC +e HD ) of the selected λ IR The ratio to the ratio "(Σe H / λ IR) "and, The sum of the optical thicknesses of the layers of low refractive index material away from the top layer, Σe L -e LD (=e LA +e LB +e LC ) of the selected λ IR The ratio to the ratio "(Σe L -e LD ) / λ IR " and both Selected infrared operating wavelength (λ IR ), in percentage terms, according to the following formula: (-0.0017×λ IR )+K3≦Σe H / λ IR ≦(-0.0017×λ IR )+K4 Here, Σe H / λ IR The smallest set in ≧5% (-0.0017×λ IR )+K3≦(Σe L -e LD ) / λ IR ≦(-0.0017×λ IR )+K4 Here, (Σe L -e LD ) / λ IRThe smallest set in ≧5% Here, K3=30% and K4=50%.

[0090] Ratio “Σe” H / λ IR " and "(Σe L -e LD ) / λ IR ", whereby it was found that an infrared anti-reflection coating having S=4 achieves the optimum infrared anti-reflection effect together with achromatic color and light reflection Rc≦11%.

[0091] Alternatively, K3 may be 32% or 34%. Alternatively, K4 may be 48% or 47%.

[0092] This allows the anti-reflective coating to be placed in an exterior-facing optical element or device, so that it can be viewed by an external observer, with both apparent aesthetics and suitable infrared anti-reflective properties.

[0093] Further optimization may be realized when S≧4 or when S=4, and the optical thickness e′ of the bottom layer having a high refractive index of the infrared anti-reflection coating is HA may be in the range of 15 to 38 nm, preferably 17 to 35 nm; and / or The optical thickness e' of the lowest layer having a low refractive index of an infrared anti-reflection coating LA may be in the range of 55 to 100 nm, preferably 60 to 95 nm.

[0094] When S≧4, or especially when S=4, and one or more of the above independent properties are obtained, the further optimal anti-reflection effect has the additional advantage that the color of the reflection in the visible wavelength range is neutral when observed at 0° (normal incidence) and also neutral at angles of incidence up to 60°.

[0095] Further optimization of the anti-reflective coating containing the four sequences can be obtained within the bounds of optical thickness e' as described later in this specification (the refractive index of the material is considered at 550 nm), which optimizes both color neutrality, low reflectance (Rc) and infrared transmittance. TIFF2024528561000002.tif62170

[0096] Within the scope of the present invention, the layers having a high refractive index are independently selected from at least one of the oxides of Zn, Sn, Ti, Nb, Zr, Hf, Ta, Ni, In, Al, Si, Ce, W, Mo, Sb, La, and Bi, and mixtures thereof, or the nitrides of Si, Al, Zr, B, Y, Ce, and La, and mixtures thereof, or zinc selenide, zinc sulfide, or zinc fluoride, and mixtures thereof.

[0097] In some preferred embodiments, the layer having a high refractive index may need to be subjected to a heat treatment as defined below for the pane: - oxides of Zr, Nb, Sn, Zn, or Ti; - Mixed oxides of two or more of Ti, Zr, Nb, Si, Sb, Sn, Zn, In; - nitrides of Si, Zr, Al, B; - Mixed nitrides of two or more of Si, Zr, Al, B, are independently selected from

[0098] In further preferred embodiments, where heat treatment may be required for the pane and manufacturing is to be simplified, the layers having a high refractive index are independently selected from mixed oxides of titanium and zirconium, silicon nitride, mixed nitrides of silicon and titanium, mixed nitrides of silicon and zirconium, mixed nitrides of silicon and hafnium, zirconium nitride, zirconium oxide, silicon doped zirconium oxide, mixed nitrides of zirconium and boron, mixed oxides of zinc and tin, niobium oxide, aluminum doped zinc oxide.

[0099] Within the scope of the present invention, the layers having a low refractive index are independently selected from silicon oxide, silicon oxynitride, silicon oxycarbide, aluminum oxide, mixed silicon aluminum oxide, mixed silicon zirconium oxide, aluminum doped silicon oxide, boron doped silicon oxide, magnesium fluoride, magnesium oxide, aluminum fluoride, yttrium fluoride, or mixtures thereof.

[0100] In some preferred embodiments, where the pane may need to be subjected to a heat treatment as defined below, the layer having a low refractive index is independently selected from silicon oxide, silicon oxynitride, silicon oxycarbide, aluminum oxide, mixed silicon aluminum oxide, mixed silicon zirconium oxide, aluminum doped silicon oxide, boron doped silicon oxide, or mixtures thereof.

[0101] Within the scope of the present invention, dopants are present in an amount of <10% by weight of the material, whereas mixed X and Y (or further) materials contain more than 15% by weight each of X and Y (or further materials) in the mixed material.

[0102] In an embodiment consistent with the previous embodiment, the top layer having a low refractive index of the antireflective coating comprising two or more sequences can comprise at least one sublayer of mixed silico-zirconium oxide. The mixed silico-zirconium oxide sublayer can comprise 5-50 mol %, preferably 8-20 mol % zirconium oxide. Such mixed silico-zirconium oxide sublayer can have a refractive index of ≦1.7, or alternatively 1.55-1.65 at 550 nm.

[0103] When such mixed silicon zirconium oxides are present in a lower refractive index top layer, they impart excellent durability to the antireflective coating. Placing this sublayer as a top sublayer in a top layer having a lower refractive index provides additional durability and resistance to scratches and external conditions.

[0104] The mixed silico-zirconium oxide top sublayer can have a geometric thickness in the range of 3-200 nm, or alternatively 4-150 nm. However, a geometric thickness of the mixed silico-zirconium oxide top sublayer in the range of 3-20 nm is already sufficient to obtain the required good durability. A thickness of >20 nm allows the anti-reflection properties of the anti-reflection coating to be adjusted. The geometric thickness is determined by the total optical thickness e of the top layer as mentioned above. UL Included in.

[0105] This provides for the application of infrared-transparent panes in optical devices that may be in contact with the exterior environment and / or subject to dust, rain, or harsh conditions. Anti-reflective coatings within the scope of the present invention may be provided without such a top sublayer and still be suitable for the primary anti-reflective purpose. However, their durability may be reduced. Thus, preferred anti-reflective coatings within the scope of the present invention may be provided with such a top sublayer and still be suitable for the primary anti-reflective purpose and may also have the additional advantage of durability against the exterior environment. This therefore determines the type of application. Thus, the present anti-reflective coatings may be used in various types of applications that may or may not be exposed to the exterior environment.

[0106] The deposition methods for the different layers of the antireflective coating include chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD), magnetron sputtering, wet coating, etc. Different layers can be deposited using different techniques.

[0107] In some embodiments, the low refractive index layer can be deposited by a PECVD method, such as a hollow cathode PECVD method, which offers the added advantages of low cost and fast deposition rate.

[0108] In some embodiments consistent with other embodiments, the infrared-transparent pane of the present invention may further include a heating system. Such heating systems may include a heating film or a printed heating system. The heating system may be provided on a first surface of the infrared-transparent pane, either above or below the anti-reflective coating, or may be located on a second surface of the infrared-transparent pane. Such a heating system should not detract from the purpose of the infrared-transparent pane and should be as thin as technically feasible.

[0109] Printed heating systems can be obtained using carbon, silver or copper based printed circuits and / or thin wires or conductive inks on a non-planar substrate (typically plastic), which are well known to those skilled in the art and will not be described further here.

[0110] Infrared transparent conductive films are well known to those skilled in the art and will not be further described herein. One example of such a film is the Canatu Carbon NanoBud heater from Canatu Corp.

[0111] The heating system should be selected, for example, to provide the infrared transmittance intended for the end use. Such a heating system may be provided to allow de-icing or defrosting of the panes depending on the end use.

[0112] In some first particular embodiments, an infrared-transparent pane of the present invention comprising a first infrared-transparent substrate having a first surface and a second surface opposite the first surface, and an infrared-antireflective coating on the first surface, as described above in various embodiments, can further comprise a second infrared-antireflective coating on the second surface opposite the first surface.

[0113] In this first particular embodiment, the first and second infrared anti-reflective coatings may be the same or different.

[0114] In this first particular embodiment, an infrared-transparent pane having an infrared anti-reflective coating on each of its first and second surfaces is preferably not provided in another embodiment in which the pane is laminated with a second pane as described below.

[0115] In a second particular embodiment, an infrared-transparent pane of the invention comprising a first infrared-transparent substrate having a first surface and a second surface opposite the first surface, and an infrared anti-reflective coating only on the first surface, as described above, may further comprise an intermediate layer and a second infrared-transparent substrate having a first surface and a second surface opposite the first surface, the second infrared-transparent substrate being laminated with its second surface to the second surface of the first infrared-transparent substrate by said intermediate layer.

[0116] In this second particular embodiment, the second surface of the first infrared-transparent substrate preferably does not have an infrared anti-reflective coating. The presence of an anti-reflective coating in contact with the intermediate layer does not appear to provide any additional benefit and is therefore preferably avoided.

[0117] The second infrared-transmissive substrate may be the same as or different from the first infrared-transmissive substrate and may be selected from glass, polymethylmethacrylate (PMMA), polycarbonate (PC), polyvinylchloride (PVC), polyethylene (PE), polybutylene (PB), or blends and composites of two or more of polymethylmethacrylate (PMMA), polycarbonate (PC), polyvinylchloride (PVC), polyethylene (PE), polybutylene (PB).

[0118] That is, the first and / or second infrared-transmissive substrates can be independently selected from glass, polymethylmethacrylate (PMMA), polycarbonate (PC), polyvinylchloride (PVC), polyethylene (PE), polybutylene (PB), or blends and composites of two or more of polymethylmethacrylate (PMMA), polycarbonate (PC), polyvinylchloride (PVC), polyethylene (PE), polybutylene (PB).

[0119] As mentioned above, the thickness of both infrared transparent substrates can independently range from 0.5 mm to about 15 mm, alternatively from 1 mm to about 10 mm, alternatively from 1 mm to about 8 mm, alternatively from 1 mm to about 6 mm, alternatively from 0.5 to 4 mm.

[0120] The thickness of both infrared-transparent substrates may be the same or different.

[0121] For example, both substrates can have the same thickness, e.g., 0.5 mm, or 0.8 mm, or 1.2 mm, or 1.6 mm, or 2.1 mm, or 3 mm. Such a symmetrical structure facilitates processing and allows conventional sizing of the lamination process.

[0122] Both substrates can also have different thicknesses, for example pane 1=0.5 mm and pane 2=2.1 mm, or pane 1=0.8 mm and pane 2=2.1 mm, or pane 1=0.5 mm and pane 2=1.6 mm, pane 1=0.8 mm and pane 2=1.6 mm, or pane 1=1.6 mm and pane 2=2.1 mm. Such an asymmetric structure allows flexibility in curvature and / or weight management and / or infrared transmittance.

[0123] As previously mentioned, the colors of both substrates may be the same or different.

[0124] The two substrates may preferably be selected from infrared-transmitting glasses due to their resistance to long-term exposure, their stability, and their low environmental impact in terms of use and reuse. A further advantage of glass is that the thickness of the glass sheet can be adjusted to reduce the overall weight of the pane, and can be the same or different for the two substrates.

[0125] The preferred glass for the infrared-transmitting pane is 15 mm in the wavelength range of 750 to 1650 nm. -1 Less than or 5m -1 It may be the aforementioned "infrared-transmitting glass" having an absorption coefficient of less than

[0126] The glass substrate may be infrared-transmissive grey glass or infrared-transmissive grey-black glass.

[0127] The intermediate layer provided for adhesion is typically selected from polyvinyl acetal, polyvinyl butyral, polyurethane, poly(ethylene-co-vinyl acetate), polyvinyl chloride, poly(vinyl chloride-co-methacrylate), polyethylene, polyolefin, ethylene acrylate ester copolymer, poly(ethylene-co-butyl acrylate), silicone elastomer, epoxy resin, acid copolymer, or mixtures thereof. Preferably, the intermediate layer may be selected from ethylene vinyl acetate and / or polyvinyl butyral and / or polyethylene terephthalate, provided that the function of the infrared transparent pane is not adversely affected.

[0128] In some cases, the interlayer may be a colored interlayer, such as gray or black, so long as infrared transmittance is provided. Such colored interlayers may provide superior aesthetics from the perspective of an external observer.

[0129] The interlayer may have a uniform thickness across its surface between the two panes, or it may have a non-uniform thickness across its surface, i.e., it may be a "wedge-shaped" interlayer.

[0130] The first and second substrates can be assembled by a lamination step in the case of flat substrates, or by a bending step in the case of curved substrates, which bending step comprises a first step of bending a pane and a second step of laminating said bent panes. These processes are well known to those skilled in the art and will not be further described here. A wide variety of shapes are available with a high degree of freedom and can be easily realized, allowing the manufacture of laminates with lengths of <1 or 2 m. 2 It is also possible to use special lamination steps at room temperature such as cold bending, which is appropriate for substrates having a size of 100 mm, in particular pieces of glass substrates, or balmy bending.

[0131] Thus, the infrared-transparent pane may be a monolithic pane, or a laminated pane.

[0132] Typically, a monolith pane includes an outer surface (P1) and an inner surface (P2).

[0133] Typically, a laminated pane comprises an outer pane having a first surface (P1) and a second surface (P2') and an inner pane having a first surface (P3') and a second surface (P4). The outer pane of a laminated glazing is the pane that contacts the outside of a defined space (vehicle or building). The inner pane is the pane that contacts the interior space of said defined space. These two panes are kept in contact with a lamination sheet or interlayer that performs the function of adhesion and contact between the two panes. The interlayer forms the contact between the first surface (P3') of the inner pane and the second surface (P2') of the outer pane.

[0134] In some embodiments consistent with the second specific embodiment described above, the first surface of the second infrared-transparent substrate may be provided with a second infrared anti-reflective coating as described above.

[0135] In such cases, the first and second infrared anti-reflective coatings may be the same or different.

[0136] For example, if the infrared-transparent pane is a monolithic infrared-transparent pane, an anti-reflective coating may be present on one or both of the P1 and P2 surfaces. In such a case, an optional heating system may be present on one of the P1 or P2 surfaces, below or above the anti-reflective coating.

[0137] For example, if the infrared-transparent pane is a laminated infrared-transparent pane, an anti-reflective coating may be present on both the P1 and P4 surfaces. In such a case, an optional heating system may be present on either one of the P1 or P4 surfaces, under or over the anti-reflective coating, or on either one of the P2' or P3' surfaces, in contact with or within an intermediate layer. No anti-reflective coating is present on either one of the P2' or P3' surfaces.

[0138] For example, a monolith or laminate infrared-transparent pane may include a first infrared anti-reflective coating optimized for transmittance at a particular operating infrared wavelength and optimized to be achromatic in reflection (in the visible) on the P1 surface, while a second infrared anti-reflective coating may be optimized only for transmittance at a particular operating infrared wavelength on the P2 or P4 surfaces. In another case, the first coating may need to be optimized for transmittance at a particular operating infrared wavelength, achromatic in reflection (in the visible) and optimized for durability with respect to exposure to the exterior environment on the P1 surface, while the second anti-reflective coating may not need the same durability on the P2 or P4 surfaces.

[0139] One advantage of such an embodiment is that the anti-reflective coatings can be designed to provide flexibility regarding the properties required for the end application, i.e., both anti-reflective coatings can be optimally designed for efficiency and cost purposes.

[0140] The monolithic or laminated infrared-transparent panes may be provided with an opacifying coating, such as an enamel or paint. Such enamel or paint may be applied onto the glazing by screen printing, roller coating, spraying, curtain coating, transfer application, etc., optionally in the presence of masking or shape / shade defining elements as known to those skilled in the art. Such enamel or paint may provide excellent aesthetics and may match the surrounding area of ​​the infrared-transparent pane.

[0141] The invention also provides an optical device comprising an infrared-transparent pane according to the above embodiments and at least one of an infrared-sensitive receptor or an infrared light source, the pane configured to transmit infrared light to a sensor and / or infrared light from the light source.

[0142] Within the scope of the present invention, infrared sensitive receptors and infrared light sources refer to devices having an operating wavelength in the range of 800-2000 nm.

[0143] An infrared sensitive receptor is sometimes called a receiving infrared optical sensor, i.e. a sensor that does not emit infrared light signals but can receive infrared light signals. A camera is a typical example of an infrared sensitive receptor, or receiving infrared optical sensor.

[0144] An infrared light source may also be referred to as an emitting infrared optical sensor, ie, a sensor that does not receive infrared light signals but can emit infrared light signals.

[0145] In some embodiments, the optical device can include both an infrared sensitive receptor and an infrared light source. Such a combined receptor and light source is sometimes referred to as an emit / receive infrared optical sensor.

[0146] Such an emitting / receiving infrared optical sensor typically refers to a sensor that first emits an infrared light signal from the vehicle towards the outside of the vehicle and then receives the infrared light signal reflected by some obstacle outside the vehicle. Lidar is a typical example of an emitting / receiving near infrared optical sensor.

[0147] The optical device may thus include an infrared-transparent pane as described above and an emitting / receiving infrared optical sensor.

[0148] The optical device is mounted such that an infrared-sensitive receptor and / or an infrared light source, or an emitting / receiving infrared optical sensor, is preferably disposed within a housing that faces an inner surface (1i) of the infrared-transparent pane according to the invention and includes an opposite outer surface (1o) facing the external environment.

[0149] For example, the present infrared-transparent panes are configured to transmit infrared light to a receptor in an optical device and / or from a light source. For example, the present panes, provided with the above-described anti-reflective coatings, may be configured to transmit infrared light at a selected operating infrared wavelength λ IR In one embodiment, the optical fiber may have improved infrared light transmittance such that the function of the receptor and / or light source is optimized in the optical fiber.

[0150] If the first surface of the infrared-transparent pane comprising the anti-reflective coating is the inner surface (1i), also called P2 in the case of a monolith or P4 in the case of a laminate as described above, this means that the anti-reflective coating is not exposed to the external environment.

[0151] If the first surface of the infrared-transparent pane comprising the anti-reflective coating is the outer surface (1o), also called P1 according to the above, this means that the anti-reflective coating may be exposed to the external environment.

[0152] If the infrared-transparent pane has an anti-reflective coating on two sides (same or different), one anti-reflective coating faces the outer surface (1o) or P1 and may be exposed to the external environment, and the other anti-reflective coating faces the inner surface (1i), which is P2 in the case of a monolith or P4 in the case of a laminate.

[0153] An advantage of the infrared-transparent panes according to the various embodiments described herein is that they can be designed to meet the requirements of various applications where high infrared light transmission is required, possibly together with color neutrality and / or high durability.

[0154] The present invention provides a cover for an infrared sensitive sensor and / or an infrared light source for infrared light in the range of 800-2000 nm comprising the present infrared transparent pane.

[0155] The use of the present infrared-transparent pane as a cover for an infrared sensor and / or an infrared light source, or for an emitting / receiving infrared optical sensor, is also provided.

[0156] Such sensors are usually placed behind a cover. This cover protects the sensor from the external environment. It can be designed as a cover only, thereby closing the housing in which the sensor is placed. Or it can be part of an integrated element, for example the sensor can be placed behind an interior or exterior element, and the cover is therefore part of this interior or exterior element. Interior elements of a vehicle are defined as glass or plastic moldings, frames, and other decorative additions to the body and interior, such as instrument panels, airbag covers, door trims, armrests, center consoles, pillar trims, trim strips, seat belt guides, or roof handles. Exterior elements include bumpers, window / door seals, wheel wells, and headlights. Manufacturers use these to add aesthetics, increase functionality, and add freedom to the design of the vehicle. The cover is naturally transparent to the operating infrared wavelengths of the sensor. Transparency of the cover to visible wavelengths is not essential.

[0157] The detection limit of the sensor is obviously related to the transmission level of the cover within the operating wavelength of the sensor, therefore it becomes necessary to increase the transmission level of the cover within the near infrared wavelength range.

[0158] Thus, infrared-transparent panes according to various embodiments described herein are well suited as covers for such sensors since they can be designed to optimally transmit infrared light by providing improved transmission at a particular operating wavelength when they include an infrared anti-reflective coating that includes an arrangement of two or more layers of high refractive index material beneath a layer of low refractive index.

[0159] The color neutrality requirement can be accommodated when the covering is visible to an outside observer by using an infrared transparent pane that includes an infrared anti-reflective coating that includes an arrangement of four or more layers of high refractive index material beneath a layer of low refractive index.

[0160] If the sensor is integrated into a part of the vehicle that can withstand a harsh external environment, such as a bumper or another exposed part of the device, the durability requirements can be ensured by the top layer of low refractive index material including a top layer of SiZrOx with a refractive index of <1.7.

[0161] The present invention provides a lidar device that includes a cover as described herein.

[0162] Thus, the present invention also provides for the use of infrared transparent panes in lidars.

[0163] The present pane allows such lidars to be used without additional transparent or opaque panes on the vehicle, such as windshields, backlights, sidelights, or pillars.

[0164] Indeed, optical devices, covers, and lidars obtained using the present infrared-transparent panes can be mounted on the exterior of motorized vehicles that may be exposed to aggressive environments subject to rain, hail, large temperature changes, and impacts from various objects such as gravel.

[0165] The infrared transparent panes may therefore be useful in transportation or architectural applications where the transmission of infrared light can be used, including displays, windows, doors, partitions, shower panels, and the like.

[0166] Transportation applications include vehicles for transportation on roads, in the air, underwater, and on water, in particular automobiles, buses, trains, ships, aircraft, spacecraft, space stations, drones, and other motorized vehicles, and thus by vehicle it is meant cars, trucks, automobiles, vans, lorries, motorbikes, buses, trams, trains, airplanes, helicopters, ships, and the like.

[0167] The invention therefore finally provides a vehicle comprising an optical device or a lidar according to above.

[0168] Terms The present invention can be described by the following clauses:

[0169] Clause 1: An infrared-transparent pane comprising a first infrared-transparent substrate having a first surface and a second surface opposite the first surface, and an infrared anti-reflective coating on the first surface, the coating comprises an array of S lamellae; - each arrangement includes a layer of high refractive index material beneath a layer of low refractive index material; - S≧2; The wavelength λ of the top layer of said coating of low refractive index material IR Optical thickness e at UL but, (λ IR *0.12)≦e UL ≦(λ IR *0.40) where λ IR An infrared transparent pane characterized in that the infrared wavelength is selected within the range of 800 to 2000 nm.

[0170] Clause 2: S≧2, and the wavelength λ of the layer of high refractive index material of the infrared anti-reflection coating IR The total optical thickness in Σe H But (λ IR *0.10)≦Σe H ≦(λ IR *0.55) in the infrared-transparent pane according to clause 1.

[0171] Clause 3: S=2 or 3, and the wavelength λ of the layer of high refractive index material of the infrared anti-reflection coating IR The total optical thickness in Σe H But (λ IR *0.28)≦Σe H ≦(λ IR *0.55), or (λ IR *0.35)≦Σe H ≦(λ IR *0.50), or (λ IR *0.38)≦Σe H ≦(λ IR*0.47) in the infrared-transparent pane according to clause 1.

[0172] Clause 4: S = 2 or 3, and the sum of the optical thicknesses of the layers having low refractive index Σe L to the visible wavelength of 550 nm, Σe L / 550nm” is the selected infrared operating wavelength (λ IR ), in percentage terms, according to the following formula: (0.0614×λ IR )-K1≦Σe L / 550nm≦(0.0614×λ IR )-K2 in accordance with 4. An infrared-transparent pane according to any one of clauses 1 to 3, wherein K1=25% and K2=-3%.

[0173] Clause 5: An infrared-transparent pane according to clause 4, wherein K1=25%.

[0174] Clause 6: An infrared-transparent pane according to clause 4, wherein K2=-3%.

[0175] Clause 7: S=2 or 3, and the wavelength λ of the top layer having a low refractive index of the infrared anti-reflection coating IR Optical thickness e at UL But (λ IR *0.15)≦e UL ≦(λ IR *0.33), preferably (λ IR *0.20)≦e UL ≦(λ IR *0.32), or (λ IR *0.22)≦e UL ≦(λ IR *0.29), or (λ IR *0.24)≦e UL ≦(λ IR *0.27) in the range of any one of clauses 1 to 4.

[0176] Clause 8: S=2 or 3, and the wavelength λ of the top layer having a high refractive index of the infrared anti-reflection coating IROptical thickness e at UH But (λ IR *0.25)≦e UH ≦(λ IR *0.50), preferably (λ IR *0.31)≦e UH ≦(λ IR *0.42) in the range of any one of clauses 1 to 4.

[0177] Clause 9: S=2 or 3, and the wavelength λ of the lowest layer LA having a low refractive index of the infrared anti-reflection coating IR Optical thickness e at LA But, e LA ≦(λ IR *0.13), preferably (λ IR *0.04)≦e LA ≦(λ IR *0.07) in an infrared-transparent pane according to any one of clauses 1 to 4.

[0178] Clause 10: S=2 or 3, and the wavelength λ of the bottom layer HA having a high refractive index of the infrared anti-reflection coating IR Optical thickness e at HA But, e HA ≦(λ IR *0.15), preferably (λ IR *0.02)≦e HA ≦(λ IR *0.11), more preferably (λ IR *0.03)≦e HA ≦(λ IR *0.10) an infrared-transparent pane according to any one of clauses 1 to 4.

[0179] Clause 11: S=4, and the wavelength λ of the layer of high refractive index material of the infrared anti-reflection coating IR The total optical thickness in Σe H But (λ IR *0.10)≦Σe H ≦(λ IR *0.45), or (λ IR *0.10)≦Σe H ≦(λ IR*0.35) in the range of infrared-transparent panes according to clauses 1 or 2.

[0180] Clause 12: S≧4, and the optical thickness e′ of the top layer UH having a high refractive index of the infrared anti-reflection coating UH 12. The infrared transparent pane according to any one of clauses 1, 2, or 11, wherein the thickness of the infrared transparent pane is in the range of 15 to 110 nm, preferably 15 to 105 nm, more preferably 20 to 100 nm.

[0181] Clause 13: S≧4 and the optical thickness e of the top layer UL having a low refractive index of the infrared anti-reflection coating UL But (λ IR *0.15)≦e UL ≦(λ IR *0.37), preferably (λ IR *0.19)≦e UL ≦(λ IR *0.33) in the range of 0.1 mm to 1.5 mm.

[0182] Clause 14: S = 4, and the sum of the optical thicknesses of the layers of high refractive index material Σe H (=e HA +e HB +e HC +e HD ) of the selected λ IR The ratio to the ratio "(Σe H / λ IR )"and, The sum of the optical thicknesses of the layers of low refractive index material away from the top layer, Σe L -e LD (=e LA +e LB +e LC ) of the selected λ IR The ratio to the ratio "(Σe L -e LD ) / λ IR " and Selected infrared operating wavelength (λ IR ), in percentage terms, according to the following formula: (-0.0017×λ IR )+K3≦ΣeH / λ IR ≦(-0.0017×λ IR )+K4, Here, Σe H / λ IR The smallest set in ≧5% (-0.0017×λ IR )+K3≦(Σe L -e LD ) / λ IR ≦(-0.0017×λ IR )+K4 Here, (Σe L -e LD ) / λ IR The smallest set in ≧5% where K3=30% and K4=50%. Infrared-transparent panes according to any one of clauses 1, 2, 11-13.

[0183] Clause 15: An infrared-transparent pane according to clause 14, wherein K3=32%, or 34%.

[0184] Clause 16: An infrared-transparent pane according to clause 14, wherein K4=48%, alternatively 47%.

[0185] Clause 17. S≧4 or S=4 and the optical thickness e' of the bottom layer having a high refractive index of the infrared anti-reflection coating HA 15. The infrared transparent pane according to any one of clauses 1, 2, 11 to 14, wherein the thickness of the pane is in the range of 15 to 38 nm, preferably 17 to 35 nm.

[0186] Clause 18: S≧4 or S=4, and the optical thickness e′ of the lowest layer having a low refractive index of the infrared anti-reflection coating LA 18. The infrared transparent pane according to any one of clauses 1, 2, 11-14, or 17, wherein the thickness of the infrared transparent pane is in the range of 55 to 100 nm, preferably 60 to 95 nm.

[0187] Clause 19: An infrared-transparent pane according to any one of clauses 1 to 18, wherein the layer having a high refractive index is independently selected from at least one of oxides of Zn, Sn, Ti, Nb, Zr, Hf, Ta, Ni, In, Al, Si, Ce, W, Mo, Sb, La, and Bi, and mixtures thereof, or nitrides of Si, Al, Zr, B, Y, Ce, and La, and mixtures thereof, or zinc selenide, zinc sulfide, or zinc fluoride, and mixtures thereof.

[0188] Clause 20: The layer having a high refractive index: - oxides of Zr, Nb, Sn, Zn, or Ti; - Mixed oxides of two or more of Ti, Zr, Nb, Si, Sb, Sn, Zn, In; - nitrides of Si, Zr, Al, B; - Mixed nitrides of two or more of Si, Zr, Al, B, An infrared-transparent pane according to any one of clauses 1 to 19, independently selected from

[0189] Clause 21: An infrared transparent pane according to any one of clauses 1 to 20, wherein the layer having a low refractive index is independently selected from silicon oxide, silicon oxynitride, silicon oxycarbide, aluminum oxide, mixed silicon aluminum oxide, mixed silicon zirconium oxide, aluminum doped silicon oxide, boron doped silicon oxide, magnesium fluoride, magnesium oxide, aluminum fluoride, yttrium fluoride, or mixtures thereof.

[0190] Clause 22: An infrared transparent pane according to any one of clauses 1 to 21, wherein the layer having a low refractive index is independently selected from silicon oxide, silicon oxynitride, silicon oxycarbide, aluminum oxide, mixed silicon aluminum oxide, mixed silicon zirconium oxide, aluminum doped zinc oxide, aluminum doped silicon oxide, boron doped silicon oxide, or mixtures thereof.

[0191] Clause 23: An infrared-transparent pane according to any one of clauses 1 to 22, wherein the top layer having a low refractive index comprises at least one sublayer of mixed silicon zirconium oxide.

[0192] Clause 24: An infrared-transparent pane according to clause 23, wherein at least one sublayer of mixed silicon zirconium oxide is a top sublayer of a top layer having a low refractive index.

[0193] Clause 25: An infrared transparent pane according to any one of clauses 1 to 24, further comprising a transparent heating system.

[0194] Clause 26: An infrared-transparent pane according to clause 25, wherein the heating system is provided on a first surface of the infrared-transparent pane either above or below the anti-reflective coating, or on a second surface of the infrared-transparent pane.

[0195] Clause 27: An infrared transparent pane according to any one of clauses 1 to 26, further comprising a second infrared anti-reflective coating on a second surface opposite the first surface.

[0196] Clause 28: An infrared transparent pane according to any one of clauses 1 to 27, further comprising an intermediate layer and a second infrared transparent substrate having a first surface and a second surface opposite the first surface, the second infrared transparent substrate being laminated by said intermediate layer with its second surface to the second surface of the first infrared transparent substrate.

[0197] Clause 29: An infrared-transparent pane according to any one of clauses 1 to 28, wherein the first and / or second infrared-transparent substrate is independently selected from glass, polymethylmethacrylate (PMMA), polycarbonate (PC), polyvinylchloride (PVC), polyethylene (PE), polybutylene (PB), or blends and composites of two or more of polymethylmethacrylate (PMMA), polycarbonate (PC), polyvinylchloride (PVC), polyethylene (PE), polybutylene (PB).

[0198] Clause 30: An infrared transparent pane according to any one of clauses 1 to 29, wherein the thickness of the first and / or second infrared transparent substrate is, independently, in the range of 0.5 mm to about 15 mm, alternatively 1 mm to about 10 mm, alternatively 1 mm to about 8 mm, alternatively 1 mm to about 6 mm, alternatively 0.5 to 4 mm.

[0199] Clause 31: Glass has a wavelength range of 750 to 1650 nm and a maximum of 15 m -1 Infrared-transparent panes according to clause 29 being "infrared-transparent glass" having an absorption coefficient of less than

[0200] Clause 33: The first and / or second infrared-transmitting substrate is 15 m in the wavelength range of 750 to 1650 nm. -1 An infrared-transparent pane according to any one of clauses 1 to 30, which is an "infrared-transparent glass" having an absorption coefficient of less than

[0201] Clause 34: An infrared-transparent pane according to any one of clauses 28 to 32, wherein a second infrared-transparent substrate is provided on a first surface thereof with a second infrared-anti-reflective coating.

[0202] Clause 35: An infrared-transparent pane according to clause 27 or 33, wherein the first and second infrared anti-reflective coatings are the same or different.

[0203] Clause 36: An optical device comprising an infrared-transparent pane according to any one of clauses 1 to 34 and an infrared-sensitive receptor and / or an infrared light source, wherein the pane is configured to transmit infrared light to a sensor and / or infrared light from the light source.

[0204] Clause 37: An optical device according to clause 35, wherein the infrared sensitive receptor and / or the infrared light source is an emitting / receiving infrared optical sensor.

[0205] Clause 38: An optical device according to any one of clauses 35 or 36, wherein the infrared-transparent pane is a cover for an infrared-sensitive receptor and / or an infrared light source.

[0206] Clause 39: A cover for an infrared sensitive sensor and / or an infrared light source of infrared light in the range of 800 to 2000 nm, the cover comprising an infrared transparent pane according to any one of clauses 1 to 34.

[0207] Clause 40: A lidar device including a cover as described in clause 39.

[0208] Clause 41: A lidar device according to clause 40, wherein the infrared transparent pane is provided with an opacifying coating.

[0209] Article 42: A vehicle including an optical device according to any one of articles 35 to 37.

[0210] Article 43: A vehicle containing a rider according to any one of articles 40 to 41.

[0211] Clause 44: Use of an infrared-transparent pane according to any one of clauses 1 to 34 as a cover for an infrared sensor and / or an infrared light source.

[0212] Article 45: Use of an infrared transparent pane according to any one of clauses 1 to 34 in a lidar device. EXAMPLES

[0213] Infrared-transparent panes comprising an infrared-transparent substrate having a first surface and a second surface opposite the first surface, and an infrared anti-reflective coating on the first surface, were obtained as follows, and their optical parameters were evaluated, taking into account certain lighting conditions and taking into account their capabilities with respect to infrared transmittance.

[0214] The infrared-transmissive substrate used in this example was clear, 1.6 mm thick infrared-transmissive glass (low iron, chromium-containing float glass) that was thoroughly cleaned prior to any coating deposition.

[0215] In the visible light, for reflection or transmission levels, the illuminant is D65, 2°, color index (a * and b *) all optical parameters are obtained with illuminant D65 and 10°.

[0216] All optical thicknesses are considered using the refractive index of the material at the infrared operating wavelength indicated. Thus, the thicknesses shown in the tables below are geometric thicknesses unless otherwise indicated, where geometric thickness = optical thickness / refractive index at the specified wavelength.

[0217] material: - TZO: Titanium dioxide / zirconium dioxide in a ratio of 55 / 45% by weight, with a high refractive index of 2.19 (at 550 nm). - SiO2: Silicon oxide with a low refractive index of 1.46 (at 550 nm) - SiZrO: Silicon oxide / Zirconium oxide in a ratio of 65 / 35% by weight with a low refractive index of 1.57 (at 550 nm)

[0218] Other refractive indices for selected materials used herein are shown. TIFF2024528561000003.tif74170

[0219] Chemical and mechanical stability is evaluated by the following test methods well known to those skilled in the art.

[0220] Chemical durability within the scope of this invention includes the test methods of the Cleveland Test, the Climate Chamber Test, and the Salt Spray Test.

[0221] Cleveland test The Cleveland test is carried out according to standard ISO 6270-1:1998 for at least 2 days, alternatively 5 days, alternatively 10 days, alternatively 15 days.

[0222] Climate Chamber Test (CC) The test consists in placing the specimens in a chamber filled with an atmosphere of HO and exposing them to temperature cycles of 2 hours each from 45°C to 55°C and back to 45°C for at least 2, 5, 10 or 21 days. CC BB is a test performed before the heat treatment of the pane (post bake), while CC AB is a test performed after the heat treatment of the pane (after bake).

[0223] Salt Spray Test (NSST) This test consists in exposing the samples to the action of a salt fog formed by spraying an aqueous solution containing 50 g / l of sodium chloride, in a chamber maintained at 35° C., for an exposure time of at least 5 days, alternatively at least 10 days, alternatively at least 21 days (full details of this test are given in the international standard ISO 9227-1990).

[0224] Mechanical durability within the scope of the present invention includes test methods of automated wet rub test, and dry brush test, before and after heat treatment.

[0225] Automated Wet Friction Test (AWRT) A piston covered with a wet cotton cloth that is kept wet is placed in contact with the layer to be evaluated and moved back and forth over the surface. The piston has a weight so that a force of 33 N is applied to a finger with a diameter of 17 mm. Rubbing the cotton over the coated surface damages (removes) the layer after a certain number of cycles. This test is used to determine the limit at which the layer becomes discoloured (partially removed) and scratches appear in it. The test is carried out for 10, 50, 100, 250, 500 and 1000 cycles at various distances on the specimen. The specimen is observed under an artificial sky to see if any discolouration or scratches on the specimen are visible by reflection. The AWRT result indicates the number of cycles at which no or very slight degradation is obtained (not visible to the naked eye under a uniform artificial sky at a distance of 80 cm from the specimen).

[0226] Dry Brush Test The Dry Brush Test (DBT) is performed according to standard ASTM D2486-00 (Test Method "A"), alternatively for at least 250 cycles, alternatively for at least 500 cycles. This test can also be performed on samples after they have been subjected to a heat treatment (referred to herein as "baking").

[0227] The results of each of the aforementioned tests are obtained by visual evaluation of the samples compared to a defined scale of a reference sample. The scales of the Cleveland Environmental Chamber and Salt Spray tests are based on an internal scale of 0 to 5, with 0 corresponding to a reference sample with significant degradation (pixels, deep dots, marks of scuffs, etc.). A value of 5 corresponds to a perfect or practically perfect surface without any marks of degradation. Intermediate values ​​(down to 0.25 units) correspond to samples on the internal scale with different levels of degradation, ranked in order of the level of degradation. Acceptable values ​​are 3 to 5. For the DBT and AWRT tests, a second internal scale is set, ranging from 0 to 10, with acceptable values ​​being 6 to 10. A value is typically the average of at least three samples in one experiment. The comparative examples in the following table were prepared along with the examples according to the invention as an internal validation of the procedure at each "run" of the experiment.

[0228] Baking conditions involve placing the sample in a convection oven at a temperature of 670° C. for 4-5 minutes.

[0229] The parameters measured were: a) Light source D65, 2° - Tv(%) = Transmittance level within the visible range - Rc(%) = Reflectance level of the coating side within the visible range b) Light source D65, 10° - Rca * =a * Color index, reflective coating side in visible range, light incidence at 8° - Rcb * =b * Color index, reflective coating side, visible range, light incidence at 8° - Rc60a * =a * Color index, reflective coating side, visible range, light incidence at 60° - Rc60b * =b * Color index, reflective coating side, visible range, light incidence at 60° c) different specific operating wavelengths λ IR Infrared transmittance at 0° incident angle of light = λ IR T(%) at λ = 60°, and light with an incident angle of λ IR T60(%)

[0230] The results generally show that: Infrared light transmission is increased compared to uncoated infrared-transparent glass For S=4, the color is neutral: -4 in reflection on the coated side at both 0° and 60° * <1 and -5 * <1 (as specified above)

[0231] These results demonstrate the suitability of the infrared transparent pane for optimized infrared light transmission.

[0232] Examples 1 to 5 As shown in Table 1 where the measured values ​​are given, the antireflective coatings of Examples 1-5 were prepared with S=2 and deposited on 1.6 mm infrared-transmitting glass substrates.

[0233] The deposition was carried out using magnetron sputtering technique.

[0234] For comparison purposes, measurements for uncoated glass are also included. TIFF2024528561000004.tif200170

[0235] ​​The values ​​show that the anti-reflective coating improves infrared transmission at the specific operating wavelengths planned and possibly even beyond some exact operating wavelengths, which can prove advantageous for obtaining coatings suitable for multiple uses or applications.

[0236] Example 1 provides an anti-reflective coating for an operating wavelength of 905 nm with an infrared transmission increase from 92% (uncoated glass) to 94.5% at 0° incidence and from 84.5% to 87.7% at 60° incidence, which is believed to be significant for the purposes of the end use of the coating.

[0237] λ IR Example 2, λ = 1310 nm IR Example 3 at λ = 1550 nm, and IR A similar increase is observed for Examples 4 and 5 at =1064 nm.

[0238] Examples 4 and 5 exhibit different colors in reflection, such as purple or greenish, which cannot be considered neutral as defined herein.

[0239] Examples 1-5 showed significantly improved chemical and mechanical durability compared to the same coatings without the SiZrOx top layer.

[0240] Examples 6 to 9 As shown in Table 2 where the measured values ​​are given, the antireflective coatings of Examples 6-9 were prepared with S=4 and deposited on 1.6 mm infrared-transmitting glass substrates.

[0241] The deposition was carried out using magnetron sputtering technique.

[0242] For comparison purposes, measurements for uncoated glass are also included. TIFF2024528561000005.tif225170

[0243] The values ​​show that the anti-reflective coating improves infrared transmission at the specific operating wavelengths planned and possibly even beyond some exact operating wavelengths, which can prove advantageous for obtaining coatings suitable for multiple uses or applications.

[0244] In Example 6, an anti-reflective coating for an operating wavelength of 905 nm is obtained, where the infrared transmittance increases from 92% (uncoated glass) to 94.1% at 0° incidence and from 84.5% to 87.1% at 60° incidence. This coating is also effective in improving the infrared transmittance at an operating wavelength of 1064 nm, demonstrating the advantage of this coating being suitable for multiple wavelengths.

[0245] λ IR Example 7, λ = 1064 nm IR Example 8 at λ = 1310 nm, and IR A similar increase is observed for Example 9 at =1550 nm. These coatings exhibit effective optical transmission at the planned operating wavelengths, but also at peripheral operating wavelengths, demonstrating flexibility for end use and applications.

[0246] This increase in infrared light transmission is believed to be significant for the purposes of the end use of the coating. The anti-reflection effect (coating side) is also noteworthy, as Rc is still <11%.

[0247] In Examples 6 to 9, a is -1.5 to 0.6. * value, and b from -3.3 to -2.5 * This indicates an achromatic color having a value of 0.015 or less, which is within the range defined by the present invention.

[0248] Examples 6-9 showed significantly improved chemical and mechanical durability compared to the same coatings without the SiZrOx top layer.

[0249] All of Examples 1-9 achieved a score of 5 on the Cleveland Test scale after 15 days, the Climate Chamber Test scale after 21 days, and the NSST Test scale after 21 days. All of Examples 1-9 achieved a score of 10 on the AWRT scale before and after baking for 1000 cycles, and the Dry Brush Test scale before and after baking for 1000 cycles.

[0250] Comparative Examples 1 to 3 As shown in Table 3 where the measured values ​​are given, anti-reflective coatings of Comparative Examples 1-3 not within the scope of the present invention were prepared with S=4 and deposited on 1.6 mm infrared-transmitting glass substrates.

[0251] The deposition was carried out using magnetron sputtering technique.

[0252] For comparison purposes, measurements for uncoated glass are also included. TIFF2024528561000006.tif87170TIFF2024528561000007.tif84170

[0253] In Comparative Example 1, an anti-reflection coating for an operating wavelength of 905 nm was obtained, with a top layer wavelength λ IR = Optical thickness at 905 nm e UL <λ IR *0.12 (i.e. 905*0.12=108.6 nm optical thickness, which is therefore equivalent to 108.6 / 1.467=74 nm geometric thickness for the SiO2 layer), the infrared transmission actually decreases from 92% (uncoated glass) to 89.6% at 0° incidence, and from 84.5% to 83.9% at 60° incidence. Such coatings are not designed to be optimal for a particular operating wavelength.

[0254] In Comparative Example 2, an anti-reflection coating for an operating wavelength of 905 nm was obtained, with a top layer wavelength λ IR = Optical thickness at 905 nm < λ IR*0.12, in which case the infrared transmission is improved from 92% (uncoated glass) to 93.7% at 0° incidence, and from 84.5% to 86.5% at 60° incidence. However, the color in transmission makes this coating unsuitable for applications that can be seen by an external observer.

[0255] The durability of Comparative Examples 1 and 2 is very low, making the coating unsuitable for applications where the coating is in contact with the exterior environment. In fact, Comparative Examples 1 and 2 achieved scores of 2 and 3.5 on the Cleveland test scale after 15 days, scores of 1 and 2 on the climate chamber test after 21 days, and scores of 3 and 2.5 on the NSST test after 21 days. Comparative Examples 1 and 2 achieved scores of 1.5 and 4.5 on the AWRT 1000 cycle scale before baking, and scores of 1 and 3.5 after baking.

[0256] Example 10 The anti-reflective coating of Example 10 was prepared with S=2 and deposited on a 1.6 mm infrared-transmitting glass substrate, as shown in Table 4, where the measured values ​​are shown. The high refractive index layer is composed of several high refractive index sublayers.

[0257] The deposition was carried out using magnetron sputtering technique.

[0258] For comparison purposes, measurements for uncoated glass are also included. TIFF2024528561000008.tif175170

[0259] The values ​​show that the anti-reflective coating improves the infrared transmission at the specific planned operating wavelength, i.e. 905 nm, and possibly even at some further specific operating wavelengths, i.e. up to 1064 nm, which proves to be advantageous in order to obtain a coating suitable for multiple uses or applications.

[0260] Example 10 provides an anti-reflective coating for an operating wavelength of 905 nm with an infrared transmission increase from 92% (uncoated glass) to 93.1% at 0° incidence and from 84.5% to 87.9% at 60° incidence, which is believed to be significant for the purposes of the end use of the coating.

[0261] Examples 11 to 15 The anti-reflective coatings of Examples 11-15 were prepared with S=4 and deposited on 1.6 mm infrared-transmitting glass substrates as shown in Table 5, where the measured values ​​are shown. The layers may be composed of several sublayers, each with a high or low refractive index.

[0262] The deposition was carried out using magnetron sputtering technique.

[0263] For comparison purposes, measurements for uncoated glass are also included. TIFF2024528561000009.tif216170

[0264] The values ​​show that the anti-reflective coating improves infrared transmission at the specific operating wavelengths planned and possibly even beyond some exact operating wavelengths, which can prove advantageous for obtaining coatings suitable for multiple uses or applications.

[0265] In Example 11, an anti-reflective coating for an operating wavelength of 905 nm is obtained, increasing the infrared transmission from 92% (uncoated glass) to 94.2% at 0° incidence and from 84.5% to 87.4% at 60° incidence. This coating is also effective in improving the infrared transmission at an operating wavelength of 1064 nm, demonstrating the advantage of this coating being suitable for multiple wavelengths.

[0266] λ IR Example 12, λ = 905 nm IR Example 13, λ = 1064 nm IRExample 14, λ = 1310 nm IR A similar increase is observed for Example 15 at =1550 nm. These coatings exhibit effective optical transmission at the planned operating wavelengths, but also at peripheral operating wavelengths, demonstrating flexibility for end use and applications.

[0267] This increase in infrared light transmission is believed to be important for end use purposes of the coating.

[0268] In Examples 11 to 15, a range of -2.0 to 0.0 * value, and b from -4.9 to -0.5 * This indicates an achromatic color having a value of 0.015 or less, which is within the range defined by the present invention.

[0269] Examples 11-15 showed significantly improved chemical and mechanical durability compared to the same coatings without the SiZrOx top layer.

[0270] Similar coatings can be obtained using other layers with a high refractive index, such as mixed oxides of titanium and zirconium, silicon nitride, mixed nitrides of silicon and titanium, mixed nitrides of silicon and zirconium, mixed nitrides of silicon and hafnium, zirconium nitride, zirconium oxide, silicon doped zirconium oxide, mixed nitrides of zirconium and boron, mixed oxides of zinc and tin, niobium oxide, aluminum doped zinc oxide, and / or other layers with a low refractive index, such as silicon oxide, silicon oxynitride, silicon oxycarbide, aluminum oxide, mixed silicon aluminum oxides, mixed silicon zirconium oxides, aluminum doped silicon oxide, boron doped silicon oxide.

Claims

1. An infrared transmissive pane comprising a first infrared transmissive substrate having a first surface and a second surface opposite the first surface, and an antireflection coating on the first surface, wherein the coating comprises an array of S thin layers, - each array comprising a layer of a high refractive index material directly below a layer of a low refractive index material, - S ≥ 2, The optical thickness e of the uppermost layer of the coating of the low refractive index material at a wavelength λ ＩＲ is ＵＬ such that (λ ＩＲ *0.12) ≤ e ＵＬ ≤ (λ ＩＲ *0.40) in the range of Here, λ ＩＲ is an infrared transmissive paint characterized by being an infrared wavelength selected within the range of 800 to 2000 nm.

2. S≧2, and the wavelength λ of the layer of high refractive index material of the infrared anti-reflection coating ＩＲ The total optical thickness in Ｈ But (λ ＩＲ * 0.10) ≦ Σe Ｈ ≦(λ ＩＲ 2. The infrared transparent pane according to claim 1, wherein the infrared transparent pane has a refractive index of 0.1*0.

55.

3. S = 2 or 3, and the total Σe of the optical thickness of the low refractive index layer Ｌ The ratio of "Σe Ｌ / 550 nm" for the visible wavelength of 550 nm ＩＲ ) is, in units of percentage values, for the selected infrared operating wavelength (λ ), the following formula: (0.0614 × λ ＩＲ ) - K1 ≤ Σe Ｌ / 550 nm ≤ (0.0614 × λ ＩＲ ) - K2 in accordance with the infrared transmissive pane according to claim 1 or 2, wherein K1 = 25% and K2 = -3%.

4. S = 2 or 3, and the optical thickness e ＩＲ at the wavelength λ ＵＬ of the uppermost layer having a low refractive index of the infrared reflection preventing coating is (λ ＩＲ *0.15) ≤ e ＵＬ ≤ (λ ＩＲ *0.33) the infrared transmissive pane according to claim 1 or 2, in the range of

5. S = 2 or 3, and the optical thickness e ＩＲ at the wavelength λ ＵＨ of the uppermost layer having a high refractive index of the infrared antireflection coating is (λ ＩＲ *0.25) ≤ e ＵＨ ≤ (λ ＩＲ *0.50). the infrared transmissive pane according to claim 1 or 2, in the range of

6. S = 2 or 3, and the optical thickness e of the lowermost layer LA having a low refractive index of the infrared reflection preventing coating at a wavelength λ ＩＲ is e ＬＡ where ＬＡ e ≦ (λ ＩＲ * 0.13). The infrared transmissive pane according to claim 1 or 2

7. S=2 or 3, and the wavelength λ of the bottom layer HA having a high refractive index of the infrared anti-reflection coating is ＩＲ Optical thickness e at ＨＡ G ＨＡ ≦(λ ＩＲ * 0.15).

8. S ≥ 4, and the optical thickness e' of the uppermost layer UH having a high refractive index of the infrared reflection preventing coating ＵＨ is in the range of 15 to 110 nm, the infrared transmissive pane according to claim 1 or 2.

9. S ≥ 4, and the optical thickness e of the uppermost layer UL having a low refractive index of the infrared reflection preventing coating ＵＬ is such that (λ ＩＲ *0.15) ≤ e ＵＬ ≤ (λ ＩＲ *0.37), the infrared transmissive pane according to claim 1 or 2.

10. S = 4, and the sum Σe of the optical thicknesses of the high refractive index material layers Ｈ (= e ＨＡ + e ＨＢ + e ＨＣ + e ＨＤ ) of the ratio "(Σe ＩＲ / λ Ｈ / λ ＩＲ )" for the selected λ The total Σe of the optical thicknesses of the layers of the low refractive index material away from the uppermost layer Ｌ -e ＬＤ (= e ＬＡ + e ＬＢ + e ＬＣ ) of the selected λ ＩＲ for the ratio "(Σe Ｌ -e ＬＤ ) / λ ＩＲ " are both Regarding the selected infrared operating wavelength (λ ＩＲ ), in units of percentage values, according to the following formula: (-0.0017 × λ ＩＲ ) + K3 ≤ Σe Ｈ / λ ＩＲ ≤ (-0.0017 × λ ＩＲ ) + K4, Here, Σε Ｈ / λ ＩＲ becomes the minimum set at ≧ 5%, (-0.0017 × λ ＩＲ ) + K3 ≤ (Σe Ｌ - e ＬＤ ) / λ ＩＲ ≤ (-0.0017 × λ ＩＲ ) + K4 Here, (Σe Ｌ - e ＬＤ ) / λ ＩＲ becomes the minimum set at ≧ 5%, wherein K3 = 30% and K4 = 50%, the infrared transmissive pane according to claim 1 or 2.

11. S ≧ 4 or S = 4, and the optical thickness e' of the lowermost layer having a high refractive index of the infrared reflection preventing coating ＨＡ is in the range of 15 to 38 nm, the infrared transmissive pane according to claim 1 or 2.

12. S ≧ 4 or S = 4, and the optical thickness e' of the low refractive index bottom layer having the infrared reflection preventing coating ＬＡ is in the range of 55 to 100 nm, the infrared transmissive pane according to claim 1 or 2.

13. The layer having a high refractive index is independently selected from at least one of oxides of Zn, Sn, Ti, Nb, Zr, Hf, Ta, Ni, In, Al, Si, Ce, W, Mo, Sb, La, and Bi, and mixtures thereof, or nitrides of Si, Al, Zr, B, Y, Ce, and La, and mixtures thereof, or zinc selenide, zinc sulfide, or zinc fluoride, and mixtures thereof, the infrared transmissive pane according to claim 1 or 2.

14. The layer having a high refractive index is: - an oxide of Zr, Nb, Sn, Zn, or Ti; - a mixed oxide of two or more of Ti, Zr, Nb, Si, Sb, Sn, Zn, In; - a nitride of Si, Zr, Al, B; - a mixed nitride of two or more of Si, Zr, Al, B, independently selected from the infrared transmissive pane according to claim 1 or 2.

15. The layer having a low refractive index is independently selected from silicon oxide, silicon oxynitride, silicon oxycarbide, aluminum oxide, mixed silicon aluminum oxide, mixed silicon zirconium oxide, aluminum-doped silicon oxide, boron-doped silicon oxide, magnesium fluoride, magnesium oxide, aluminum fluoride, yttrium fluoride, or mixtures thereof, the infrared transmissive pane according to claim 1 or 2.

16. The infrared-transmissive pane according to claim 1 or 2, wherein the layer having a low refractive index is independently selected from silicon oxide, silicon oxynitride, silicon oxycarbide, aluminum oxide, mixed silicon aluminum oxide, mixed silicon zirconium oxide, aluminum-doped zinc oxide, aluminum-doped silicon oxide, boron-doped silicon oxide, or a mixture thereof.

17. The infrared-transmissive pane according to claim 1 or 2, wherein the top layer having a low refractive index includes at least one sublayer of mixed silicon zirconium oxide.

18. The infrared-transmissive pane according to claim 17, wherein at least one sublayer of mixed silicon zirconium oxide is the top sublayer of the top layer having a low refractive index.

19. The infrared-transmissive pane according to claim 1 or 2, further comprising a transparent heating system.

20. The infrared-transmissive pane according to claim 19, wherein the heating system is provided on the first surface of the infrared-transmissive pane either above or below the antireflection coating, or on the second surface of the infrared-transmissive pane.

21. The infrared-transmissive pane according to claim 1 or 2, further comprising a second infrared antireflection coating on the second surface opposite to the first surface.

22. The infrared-transmissive pane according to claim 1 or 2, further comprising an intermediate layer and a second infrared-transmissive substrate having a first surface and a second surface opposite to the first surface, the second infrared-transmissive substrate being laminated to the second surface of the first infrared-transmissive substrate by the intermediate layer.

23. The infrared-transmissive pane according to claim 1 or 2, wherein the first and / or second infrared-transmissive substrate is glass, polymethyl methacrylate (PMMA), polycarbonate (PC), polyvinyl chloride (PVC), polyethylene (PE), polybutylene (PB), or a mixture and composite material, and is independently selected from two or more mixtures and composite materials of polymethyl methacrylate (PMMA), polycarbonate (PC), polyvinyl chloride (PVC), polyethylene (PE), polybutylene (PB).

24. The thickness of the first and / or second infrared transmissive substrate is independently in the range of 0.5 mm to about 15 mm, or 1 mm to about 10 mm, or 1 mm to about 8 mm, or 1 mm to about 6 mm, or 0.5 to 4 mm, the infrared transmissive pain according to claim 1 or 2.

25. The glass is "infrared-transmitting glass" having an absorption coefficient of less than 15 m-1 in the wavelength range of 750 to 1650 nm. The infrared-transmitting pane according to claim 1 or 2. －１ ​

26. The first and / or second infrared-transmissive substrate is "infrared-transmissive glass" having an absorption coefficient of less than 15 m －１ in the wavelength range of 750 to 1650 nm. The infrared-transmissive paint according to claim 1 or 2.

27. The infrared transmissive pain according to claim 22, wherein a second infrared antireflection coating is provided on a first surface of the second infrared transmissive substrate.

28. The infrared transmissive pain according to claim 21, wherein the first and second infrared antireflection coatings are the same or different.

29. An optical device including the infrared transmissive pain according to claim 1 or 2, and an infrared sensitive receptor and / or an infrared light source, wherein the pain is configured to transmit infrared light to the sensor and / or infrared light from the infrared light source.

30. The optical device according to claim 29, wherein the infrared sensitive receptor and / or the infrared light source is an emission / reception infrared optical sensor.

31. The optical device according to claim 29, wherein the infrared transmissive pain is a cover for the infrared sensitive receptor and / or the infrared light source.

32. A cover for an infrared sensitive sensor and / or an infrared light source for infrared light in the range of 800 to 2000 nm, including the infrared transmissive pain according to claim 1 or 2.

33. A lidar device including the cover according to claim 32.

34. The lidar device according to claim 33, wherein an opacifying coating is provided on the infrared transmissive pain.

35. A vehicle including the optical device according to claim 29.

36. A vehicle including the lidar according to claim 33.

37. Use of the infrared transmissive pain according to claim 1 or 2 as a cover for an infrared sensor and / or an infrared light source.

38. Use of the infrared transmissive pain according to claim 1 or 2 in a lidar device.