Laminated glazing and process

Abstract

This disclosure relates to laminated window glass and a process. A laminated window glass and a process for producing shaped laminated window glass are disclosed. The laminate includes a first glass layer having a first surface and a second surface, a second glass layer having a third surface and a fourth surface, at least one polymer layer between the first and second glass layers, and a shielding strip surrounding at least a portion of the periphery of the window glass. The shielding strip has at least one sensor window and includes a first shielding layer and a second shielding layer. The first glass layer has a first shielding layer adhered to at least a portion of the periphery of the first or second surface. The first shielding layer includes at least one first sensor window portion with partial optical distortion of the first sensor window. The second glass layer has a second shielding layer adhered to at least a portion of the periphery of the third or fourth surface. The second shielding layer includes at least one second sensor window portion with partial optical distortion of the second sensor window. The partial optical distortion of the first and second sensor windows are each controlled such that the absolute magnitude of the optical distortion of the sensor window is lower than the absolute magnitude of the optical distortion of the first and second sensor windows.

Description

[0001] This divisional application is a divisional application of Chinese patent application No. 202080031681.1, filed on March 26, 2020, entitled "Laminated Window Glass and Process". Technical Field

[0002] This invention relates to glazings, automotive window glass, and processes for producing such window glass. Background Technology

[0003] Laminated window glass, which consists of two panes of glass material (usually glass) laminated together by a plastic interlayer (such as polyvinyl butyral, PVB), can be used in buildings and especially for automotive windows.

[0004] Windshields, and increasingly other automotive windows, are typically laminated glass and often have an obscuration band around their perimeter. This obscuration band is usually black or very dark and generally opaque to visible light (and often other wavelengths, such as UV). The obscuration band is used to conceal components on the window glass, such as fasteners, and also provides UV protection for adhesives used to hold the window glass in place.

[0005] Masking tape can be made of enamel. Such enamel, once fired, withstands weathering and abrasion. Masking tape can be applied by screen printing enamel ink onto glass. Enamel ink typically comprises glass frit (fluid), pigments, and liquid components (e.g., oil) to improve its screen printing performance. After screen printing, the enamel ink can be cured (e.g., by UV irradiation) or dried (e.g., by heating to up to about 300°C), and can then be fired at high temperatures to melt the flux and ensure adhesion to the glass surface.

[0006] The common practice is to number the surfaces of laminated window glass, starting with the surface facing the exterior of the vehicle or building in which the window glass is installed. Therefore, surface 1 is the exterior-facing surface and is exposed. In a laminate comprising two layers of window glass material, surface 1 is the outer surface of the outer layer facing outwards. Surface 2 is the interior-facing surface of the outer layer, i.e., the surface of the outer layer facing the interior of the vehicle or building. Surface 2 is not exposed because it is in contact with and covered by the plastic interlayer. Surface 3 is the exterior-facing surface of the inner layer, i.e., the surface of the inner layer facing the exterior of the vehicle or building. Similar to surface 2, surface 3 is not exposed because it is in contact with and covered by the plastic interlayer. Therefore, surfaces 2 and 3 are either not exposed or covered. Surface 4 is the interior-facing surface of the inner layer, i.e., the exposed surface facing the interior of the vehicle or building.

[0007] In laminated glass (e.g., windshields), a masking strip can be printed on surface 4 or the inner surface of the laminate (e.g., surface 2, the glass / polymer interface inside the laminate). Window glass with a masking strip on a single glass layer is typically formed by heating each glass substrate to a high temperature after enamel is applied to it. Printing the masking strip on the inner surface of the laminate (e.g., surface 2 or surface 3) can reduce perspective distortion that can sometimes occur. WO-A-2017 / 159452 discloses laminated glass with printing on surfaces 2 and 4 in some embodiments, wherein reduced perspective distortion is present near the masking strip.

[0008] Enameling is often produced through a heating process. After forming, optical distortion can occur at the boundary between the printed and non-printed areas of the glass. This type of optical distortion is sometimes referred to as a "burnline," and it tends to extend parallel to the boundary.

[0009] Attempts have been made to reduce or eliminate burn marks by modifying bending process parameters (such as temperature distribution) and / or by designing, building and installing shielding on glass bending tools / dies.

[0010] EP-A-0 415 020 discloses a method for preferentially heating a glass sheet with a decorative ceramic enamel boundary without adversely affecting the optical quality of the glass. Preferential heating is achieved by using a heater that radiates thermal energy at selected wavelengths, which are more readily absorbed by the enamel than by the glass, thus allowing the enamel to heat up faster than the glass. In one particular embodiment, the glass with the ceramic enamel boundary is preheated to a temperature above its strain point temperature. The coated glass is then exposed to a quartz heater to preferentially heat the enamel to a sufficiently high temperature to fire it onto the glass. The ceramic enamel is then allowed to cool to the temperature of the rest of the glass.

[0011] US-B-5,443,669 discloses a process for producing laminated glass panels with single or double curvature, particularly for motor vehicles, and more particularly for producing glass panels with printed patterns, especially for motor vehicle windshields where the pattern may be a boundary. The printed pattern is formed using enamel ink.

[0012] Unfortunately, such attempts have yielded unsatisfactory solutions and suffer from drawbacks such as high additional costs and time associated with designing, constructing, installing, and optimizing tool shielding. Furthermore, in terms of glass forming in other areas, general optical quality can be negatively affected by the additional shielding, as it influences the forming of the rest of the glass. Moreover, the attempted solutions may lead to further aesthetic problems caused by under-firing of the enamel ink in the shielding strip.

[0013] More successful attempts to address the burn mark problem could involve modifying the properties of the enamel, as discussed in WO-A-2017 / 068368, to increase spectral reflectance in the NIR (near-infrared) and IR (infrared) wavelength ranges (which can be equivalent to reducing the difference in emissivity between printed and non-printed glass surfaces, especially at medium to high temperatures).

[0014] Advanced Driver Assistance Systems (ADAS) (such as those manufactured by Mobileye and others) are becoming increasingly common in vehicles and can be used for lane departure warnings, autonomous emergency braking, high beam assist, speed limit recognition, and other applications. Many of these systems rely on one or more cameras, which are typically mounted on the inner surface of the windshield (i.e., surface 4). Preferred locations for mounting the cameras (one or more) are towards the upper edge of the windshield, generally in the center, or symmetrical about the centerline of the windshield, i.e., near the rearview mirrors, which are typically positioned in the same area of ​​the windshield. The cameras (one or more) are often positioned behind a shading strip (when viewed from outside the vehicle), thus requiring an area free from the enamel, ink, etc., that constitutes the shading strip through which the cameras (one or more) can view the area in front of the vehicle.

[0015] Areas without a shielding strip can take the form of holes or notches within the shielding strip, and are often referred to as "camera windows." Thus, for example, a camera window may or may not be surrounded by a shielding strip. The same considerations regarding providing forward visibility also apply to sensors, such as rain or light sensors located on surface 4 of the windshield, which are typically situated within the same portion of the windshield; therefore, the term can be generalized as "sensor windows."

[0016] Optical distortion from the camera window can limit the effectiveness of cameras and ADAS applications. US-A-2018 / 118116 discloses an automotive camera system including a black layer disposed in the upper central region of the windshield. EP-A-1605 729 discloses a vehicle windshield equipped with an imaging device for observation through an observation area including a resistance heating element for heating the observation area to mitigate the effect of ice or condensation on the field of view through the observation area. DE 20 2018 105 625 U1 discloses a vehicle panel with two printed areas, wherein the optical effect of the first printed area can be compensated by the optical effect of the second printed area.

[0017] There is a need to further reduce optical distortion in or near ADAS camera windows, including those in shielding strips printed on or near the laminated window glass. This is especially true because the permissible amount of optical distortion in ADAS camera windows decreases over time as ADAS performance requirements increase. Summary of the Invention

[0018] The purpose of this invention is to address this need.

[0019] In a first aspect, the present invention therefore provides a laminated window glass comprising a first glass layer having a first surface and a second surface, a second glass layer having a third surface and a fourth surface, at least one polymer layer located between the first and second glass layers, and a shielding strip surrounding at least a portion of the periphery of the window glass, the shielding strip having at least one sensor window and including a first shielding layer and a second shielding layer, the first glass layer having a first shielding layer adhered to at least a portion of the periphery of the first surface or the second surface, the first shielding layer including at least one first sensor window portion having optical distortion of the first sensor window portion, the second glass layer having a second shielding layer adhered to at least a portion of the periphery of the third surface or the fourth surface, the second shielding layer including at least one second sensor window portion having optical distortion of the second sensor window portion, wherein both the optical distortion of the first sensor window portion and the optical distortion of the second sensor window portion are controlled such that the absolute magnitude of the optical distortion of the sensor window is lower than the absolute magnitude of the optical distortion of the first sensor window and the optical distortion of the second sensor window.

[0020] This is highly advantageous because controlling the optical distortion of the sensor window portion on each layer (“sensor window portion optical distortion”) allows for balancing the overall optical distortion within the sensor window, resulting in a significant reduction in distortion through the laminated window glass, thus allowing for a clearer field of view, for example, in ADAS camera systems.

[0021] In window glass, optical distortion is generally considered a characteristic of the image that an observer (or camera and other optical sensors) sees, potentially causing pixel shifts. Optical power is generally considered a characteristic of window glass (e.g., glass) that can cause optical distortion. Optical power is typically measured in diopter (equivalent to 1 / m; the reciprocal of the lens focal length, P = 1 / f), or more commonly, in millidopter (mdpts: 1 mdpt = 0.001 diopter). In this specification, unless the context requires otherwise, optical distortion and optical power are used interchangeably.

[0022] Surprisingly, the inventors of this invention have discovered that optical distortion in the sensor window portion of each layer is not always high, but when laminated to another layer, mismatched surfaces may exist, which can lead to higher overall optical power and therefore higher optical distortion. By balancing the optical distortion of the two layers, particularly the sensor window portion of each layer, this invention enables a reduction in overall optical power / distortion. Overall optical distortion is reduced by balancing the optical distortion of the sensor window portion of each layer. The optical distortion of the sensor window in each layer is controlled so that they balance or compensate for each other, resulting in low net distortion. This not only has the effect of significantly reducing the overall magnitude of optical distortion / optical power, but also reduces abrupt changes in optical power / distortion across the entire window glass. Ideally, the optical distortion in the two layers will be equal and opposite, causing them to cancel each other out.

[0023] The present invention also provides a laminated window glass comprising a first glass layer having a first surface and a second surface, a second glass layer having a third surface and a fourth surface, at least one polymer interlayer extending between the first and second glass layers, a shielding strip surrounding at least a portion of the periphery of the window glass, and at least one sensor window provided in the shielding strip. The shielding strip includes a first shielding layer and a second shielding layer disposed on the first and second glass layers. The first glass layer has a first shielding layer disposed on at least a portion of the periphery of the first or second surface, the first shielding layer including at least one first sensor window portion with associated optical distortion. The second glass layer has a second shielding layer disposed on at least a portion of the periphery of the third or fourth surface, the second shielding layer including at least one second sensor window portion with associated optical distortion.

[0024] The first and second shielding layers are formed of enamel, and

[0025] The construction of the sensor window portion and at least one characteristic of the enamel are selected such that the optical distortion associated with each of the sensor window portions compensates for each other, so as to produce a reduced net optical distortion in the window glass.

[0026] Preferably, the selected characteristic of enamel is its infrared reflectivity.

[0027] The first and second sensor window portions preferably have sufficiently high light transmittance in the visible spectrum region to allow the ADAS camera to view through the laminated window glass. Currently, ADAS cameras and other sensors are generally mounted on windshields, and most countries require windshields to have at least 70% visible light transmittance. Regulatory requirements aside, visible light transmittance (e.g., according to ISO 9050) is preferably higher than 55%, 60%, more preferably higher than 70%, and most preferably higher than 75%. As ADAS cameras become more sensitive and the minimum light transmittance required for them to operate satisfactorily decreases, they may be mounted on other window glass, such as backlights (i.e., rear windows), and such windows may have visible light transmittance below 20% (in the case of privacy windows), or below 30%, or below 40%, or below 50%.

[0028] Generally, the shielding layer and thus the shielding strip can be adapted to be substantially opaque to visible light, such that the ISO 9050 visible light transmittance of the shielding layer of the window glass is 1% or less, preferably 0.5% or less, and more preferably 0.1% or less.

[0029] The glass substrate for each glass layer can be unformed (e.g., it can be flat glass), but is preferably formed glass substrate and can have a thickness such as, for example, 1 mm to 5 mm. Typically, a shielding layer is applied to the flat glass substrate, which is then formed, for example, to form an automotive windshield or windshield.

[0030] The polymer layer may include PVB (typically <1 mm thick, e.g., 0.76 mm thick). If higher performance or functionality is required (e.g., sunlight control), there may be two PVB layers sandwiched between another plastic layer (e.g., each 0.3 to 0.4 mm thick). For example, the additional plastic layer may be PET and may have a sunlight control coating (e.g., having at least one silver layer and two or more dielectric layers) to provide such sunlight control.

[0031] The shielding layer can be tinted to provide sufficient shielding and can preferably be very dark, and more preferably substantially black in visible colors. Typically, the shielding layer, and thus the shielding band, will form a band that surrounds at least a portion of the perimeter of the window glass.

[0032] Typically, the first sensor window portion and the second sensor window portion are essentially free of enamel.

[0033] In one embodiment, the shape of the first sensor window portion may be different from the shape of the second sensor window portion, thereby controlling the optical distortion of the first sensor window portion and the optical distortion of the second sensor window portion.

[0034] Therefore, independently, the shape of the first sensor window portion and / or the second sensor window portion can be square, rectangular, trapezoidal, elliptical, or circular.

[0035] Typically, the first sensor window portion and / or the second sensor window portion are partially or completely surrounded by the first shielding layer and / or the second shielding layer, respectively. The first shielding layer and / or the second shielding layer may be located on one, two, three, or four sides of the first sensor window portion and / or the second sensor window portion.

[0036] To improve control over optical distortion in the window portion, at least a portion of the periphery of the first sensor window portion or the second sensor window portion can be patterned, optionally including spots, lines, fades, feathered edges, or jagged fades.

[0037] In another embodiment of the invention, the first and second shielding layers may be formed of materials with different infrared reflectivities, thereby allowing control of optical distortion in the first and second sensor window portions.

[0038] For example, the first and / or second shielding layer can have a relatively high infrared reflectivity, such that at least a portion of the first and / or second shielding layer has an infrared reflectivity of 21% or higher in the region of 800 nm to 2250 nm wavelength range. The infrared reflectivity of this portion in the 800 nm to 2250 nm wavelength range can be 24% or higher, preferably 27% or higher, more preferably 30% or higher, even more preferably 32% or higher, still more preferably 35% or higher, and most preferably 37% or higher. The region in the 800 nm to 2250 nm wavelength range can extend to more than 400 nm or greater, preferably 450 nm or greater, more preferably 550 nm or greater, and most preferably 610 nm or greater.

[0039] Infrared reflectance can be measured in this wavelength range using a spectrophotometer (e.g., Perkin Elmer Lambda 9500).

[0040] An important characteristic is the difference in infrared reflectance between the first and second shielding layers. This difference may be due to one shielding layer having a typical infrared reflectance, for example, in the range of 17% to 20%, while the other shielding layer may have a high infrared reflectance, for example, 21% or higher, as listed above, or a low infrared reflectance, for example, 16% or lower. Alternatively, one shielding layer may have a high infrared reflectance, while the other shielding layer may have a low infrared reflectance. Preferably, the difference in infrared reflectance between the first and second shielding layers is at least 5%, 7%, 9%, 12%, 15%, 18%, or 21%.

[0041] Therefore, generally speaking, depending on the process conditions, high infrared reflectivity shielding layers can have an average infrared reflectivity of 30% to 50%. Shielding layers that are not specifically designed to provide high IR reflectivity may have an IR reflectivity of about 17% or less, or 20% or less, in the IR range (800-2000 nm), while high reflectivity enamels may have a reflectivity of 30% or more over most of that range.

[0042] The second and / or first shielding layer may have a relatively low infrared reflectivity, such that at least a portion of the first and / or second shielding layer has an infrared reflectivity of 20% or 16% or lower in the wavelength range of 800 nm to 2250 nm.

[0043] The first and / or second masking layers may include enamel. Typically, enamel comprises glass frit and inorganic pigments. The inorganic pigments may be selected from ferrochrome pigments, ferrite pigments, chromite pigments, or ferrite / chromite (also known as ferrous chromite) pigments.

[0044] By selecting suitable infrared and / or near-infrared reflective pigments and including an appropriate amount of infrared reflective pigments in the enamel, the enamel can be adapted to provide suitable (e.g., high or low) emissivity characteristics. The enamel may contain 10 wt% to 50 wt% inorganic pigments, preferably 10 wt% to 40 wt%, more preferably 12% to 32%. The enamel may contain 20 wt% to 80 wt% glass frit.

[0045] Oxide glass frits may include particles of at least one compound selected from silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, compounds containing fluoride ions (e.g., fluorite, fluorapatite, cryolite, etc.), bismuth oxide, zinc oxide, boron oxide, potassium oxide, sodium oxide, calcium oxide, barium oxide, lead oxide, lithium oxide, phosphorus oxide, molybdenum oxide, strontium oxide, and magnesium oxide.

[0046] Suitable inorganic pigments may include pigments selected from the following: Fe / Cr pigments, Co / Al pigments, Co / Al / Cr pigments, Co / Ti pigments, Co / Cr pigments, Ni / Fe / Cr pigments, Ti / Cr / Sb pigments, Fe pigments, Cr pigments and / or mixtures of two or more of these pigments.

[0047] Therefore, inorganic pigments can be selected from chromium-iron pigments, ferrite pigments, chromite pigments, or ferrite / chromite (also known as iron chromite) pigments.

[0048] Depending on the design of the laminated window glass, the enamel on the first glass layer and the enamel on the second glass layer can be independently selected from high infrared reflectance enamel or low infrared reflectance enamel.

[0049] The infrared reflectivity of the first or second shielding layer can be controlled by using appropriate enamels with different infrared reflectivities or different emissivities.

[0050] Therefore, the enamel of the first shielding layer and / or the enamel of the second shielding layer can be selected from low infrared reflectance enamel or high infrared reflectance enamel, thereby allowing control of optical distortion of the first sensor window portion and optical distortion of the second sensor window portion.

[0051] Therefore, the infrared reflectance of high IR reflectance enamel can be 21% or higher in the wavelength range of 800 nm to 2250 nm. The infrared reflectance in the wavelength range of 800 nm to 2250 nm can be 24% or higher, preferably 27% or higher, more preferably 30% or higher, even more preferably 32% or higher, still more preferably 35% or higher, and most preferably 37% or higher.

[0052] The region of wavelength range from 800nm ​​to 2250nm can be extended to more than 400nm or greater, preferably 450nm or greater, more preferably 550nm or greater, and most preferably 610nm or greater.

[0053] Further control of optical distortion can be achieved if the periphery of the first sensor window portion or the second sensor window portion includes a shielding frame portion with a lower (or higher) infrared reflectance than the shielding layer on the rest of the glass layer and / or a lower (or higher) infrared reflectance than the shielding layer on other glass layers.

[0054] Therefore, the periphery of the second sensor window portion may include a shielding frame portion.

[0055] The use of ceramic / enamel in the shielding layer / strip is advantageous because it utilizes known processes and enamel has proven its durability and performance. The enamel / ceramic layer may be useful at the window glass edges for protection (e.g., adhesives) against the vehicle's bonding, thus avoiding the need for color matching with other methods applied to sensor windows. This invention allows for a reduction in optical distortion / power close to that of molded glass without a ceramic layer, thus offering significant advantages because the use of a shielding layer formed of ceramic (i.e., enamel) is inherently advantageous.

[0056] In another embodiment, the first and second sensor window portions can have different sizes, i.e., one of the two sensor window portions can be larger than the other. For example, the first sensor window portion can be larger than the second window portion. More specifically, the first sensor window portion can have an x-axis dimension and / or a y-axis dimension, and the second sensor window portion can have an x-axis dimension and / or a y-axis dimension, wherein the x-axis dimension and / or y-axis dimension of the first sensor window portion are different from the x-axis dimension and / or y-axis dimension of the second sensor window portion, thereby allowing control over the optical distortion of the first sensor window portion and the optical distortion of the second sensor window portion.

[0057] The x-axis dimension of the first sensor window portion can be greater than the x-axis dimension of the second sensor window portion, and / or the y-axis dimension of the first sensor window portion can be greater than the y-axis dimension of the second sensor window portion.

[0058] The smaller window portion can be positioned such that it is offset relative to the larger window portion at each end of the dimension. Preferably, the smaller window portion is positioned such that it is offset relative to the larger window portion at each end of the dimension. The offsets at each end of the dimension can be substantially the same or can be different.

[0059] Optical distortion in the first and / or second sensor window portions appears to contribute to the optical power / distortion of the sensor window. Therefore, preferably, the first and / or second sensor window portions have optical distortion controlled within the range of -405 to +405 millidiopters, optionally within the range of -310 to +310 millidiopters. More preferably, the first and / or second sensor window portions have optical distortion within the range of -205 to +205 millidiopters, optionally within the range of -185 to +185 millidiopters, and preferably within the range of -155 to +155 millidiopters.

[0060] This invention is highly advantageous because the control (and balancing) of optical distortion in the first and second sensor window portions significantly improves the sensor window, particularly producing distortion values ​​within the range of ±250 mdpt (i.e., the absolute amplitude of optical distortion in the sensor window is 250 mdpt), ±245 mdpt, ±205 mdpt, ±200 mdpt, ±195 mdpt, ±190 mdpt, ±175 mdpt, ±165 mdpt, ±160 mdpt, ±157 mdpt, and 152 mdpt. Sensor windows with optical power / distortion within ±147mdpt, ±145mdpt, ±142mdpt, ±137mdpt, ±132mdpt, ±127mdpt, ±122mdpt, ±117mdpt, ±112mdpt, ±107mdpt, ±102mdpt, ±97mdpt, ±92mdpt, ±87mdpt, ±82mdpt, ±77mdpt, ±72mdpt, ±67mdpt, ±65mdpt, ±62mdpt, or ±60mdpt.

[0061] The range of optical distortion / optical power can be wider or narrower, and can depend on the tilt angle of the window glass, the window size, the window design, and the bending process.

[0062] To reduce condensation and / or icing in the sensor window, one or each sensor window portion may include a heating device, optionally including an electrically heated grid, for example, including a resistance heating wire or other conductor.

[0063] It may be desirable to use laminated window glass with two or more sensors or cameras. Therefore, in some cases, laminated window glass may include two or more sensor windows.

[0064] In a second aspect, the present invention provides an automotive windshield comprising a laminated window glass according to a first aspect of the present invention.

[0065] In a third aspect, the present invention provides a process for producing molded laminated window glass, the process comprising: providing a first glass substrate having a first surface and a second surface, and a second glass substrate having a third surface and a fourth surface; applying a first shielding layer to at least a first portion of the first or second surface of the first glass substrate, the first shielding layer including at least one first sensor window portion having controlled first sensor window portion optical distortion; applying a second shielding layer to at least a first portion of the third or fourth surface of the second glass substrate, the second shielding layer including at least one second sensor window portion having controlled second sensor window portion optical distortion; optionally, forming the first glass substrate and the second glass substrate by heating the first glass substrate and the second glass substrate to a temperature above 570°C; placing at least one polymer layer between the first and second glass substrates; and laminating the first glass substrate, the polymer layer, and the second glass substrate, whereby, by controlling the first sensor window portion optical distortion and the second sensor window portion optical distortion, the absolute magnitude of the optical distortion of the sensor window is less than the absolute magnitude of the first sensor window optical distortion and the second sensor window optical distortion.

[0066] This invention is applicable to any forming process for flat glass, whether for vehicles or buildings. For example, forming can be achieved by press bending, i.e., pressing a heat-softened glass sheet between opposing bending dies, or by sag (gravity) bending, i.e., allowing the heat-softened glass sheet to deform under its own weight while supported on a sag bending die, typically in an annealing furnace. Forming can also be achieved by die-assisted sag bending, where the heat-softened glass sheet sags and bends, but a portion of the glass sheet is also pressed by a pad or die.

[0067] It has been found that different forming processes tend to produce different optical powers within the glass layers. For example, drooping bends are affected by strong and concentrated burn marks on surface 4, while burn marks formed on surface 2 tend to have a more moderate and dispersed optical power, i.e., distributed over a wider area. This trend can be controlled by using infrared-reflective ink on surface 4, thereby reducing the optical power generated on surface 4 and achieving a desired balance between surfaces 2 and 4. In this way, reduced net optical distortion is achieved.

[0068] On the other hand, bending tends to produce weak burn marks on surface 4, while burn marks on surface 2 are variable and seem to depend more on the characteristics of the part being produced. If the burn mark on surface 2 is stronger than that on surface 4, it's somewhat counterintuitive to use an ink with lower infrared reflectivity on surface 4, which could actually increase optical distortion on that surface. However, by better balancing the distortion on surface 2, lower net optical distortion can be achieved. Alternatively, if the burn mark on surface 2 is weaker than that on surface 4, then a more reflective ink can be used on surface 4, or a less reflective ink can be used on surface 2, depending on the absolute magnitude of the two distortions and the inks available.

[0069] Therefore, it is desirable to select methods to reduce burn marks in the molding process during use, especially considering the characteristics of the inks used, such as infrared reflectivity.

[0070] Applying a first and a second masking layer may include applying enamel ink, which includes inorganic pigments and glass frit.

[0071] The other features of the third aspect are largely as described above regarding the first aspect, with appropriate modifications. Attached Figure Description

[0072] The invention will now be described by way of example only and with reference to the accompanying drawings, in which:

[0073] Figure 1 (a) is a schematic plan view of an embodiment of laminated window glass according to the present invention. Figure 1 (b) is Figure 1 (a) is a schematic cross-sectional view of a portion of the window glass along line AA.

[0074] Figure 2 This is a schematic plan view of another embodiment of the laminated window glass according to the present invention.

[0075] Figure 3 A schematic diagram of the sensor window used in the example is shown: (a) the second window portion of surface 4 is larger than the first window portion of surface 2, with offsets at the top, bottom, and sides; (b) the second window portion of surface 4 is again larger (compared to the first window portion of surface 2), with fades at the top and bottom and offsets at the top, bottom, and sides; (c) an even larger second window portion of surface 4 with offsets around it (compared to the first window portion of surface 2), and a high IR reflectivity / low emissivity shielding frame around the second window portion of surface 4.

[0076] Figure 4 This is a graph showing the relationship between optical power and pixel position in Example 1.

[0077] Figure 5 This is a graph showing the relationship between optical power and pixel position in Example 2.

[0078] Figure 6 This is a graph showing the relationship between optical power and pixel position in Example 3.

[0079] Figure 7 This is a graph showing the relationship between optical power and pixel position in Example 4.

[0080] Figure 8 This is a graph showing the relationship between optical power and pixel position in Example 5.

[0081] Figure 9 Alternative schematic diagrams of various sensor window designs are shown, illustrating the shapes of the first window portion on surface 2 (S2) and the second window portion on surface 4 (S4). Detailed Implementation

[0082] Figure 1 (a) A laminated window glass 2 according to the invention is illustrated. The laminated window glass 2 is a windshield of a motor vehicle. The laminated window glass 2 comprises two glass layers laminated together by an interlayer extending between the glass layers. The interlayer comprises a layer of polymeric plastic material, such as a layer of polyvinyl butyral (PVB). The laminated window glass 2 has a peripheral shielding strip 6 surrounding a transparent portion 4 of the window glass 2. The shielding strip 6 is optically opaque and conceals multiple parts of the vehicle, and also provides protection for the adhesive against UV light.

[0083] Within the shielding strip 6, at the upper edge of the windshield (when mounted in a vehicle), there is an optically transparent Advanced Driver Assistance System (ADAS) camera sensor window 10, i.e., the enamel area without the shielding strip 6. When mounted in a vehicle, the ADAS camera sensor window 10 allows the camera to form an image viewed through the upper part of the windshield.

[0084] When the glass plate is heated to the high temperature required for bending, a difference in heating rate was observed in the portion of the window glass with the black shielding strip 6 compared to the transparent portion 4 of the glass window 2 and the transparent camera window 10. These differences in heating rates lead to the development of localized temperature differences within the glass, which in turn result in viscosity differences in the thermally softened glass. These differences are believed to cause optical distortion. Optical distortion was found to occur after the glass layer was heated / shaped at the periphery of the transparent portion 8, near the edge of the shielding strip 6, and in the portion of the glass layer in the sensor window 10. The heating / shaping of the glass layer can be performed by drooping bending or pressing, and as previously mentioned, the degree and type of optical distortion can differ between different methods. Optical distortion may also occur after the printed glass layer cools, again believed to be due to the development of temperature differences.

[0085] Figure 1 (b) shows Figure 1(a) Cross section of line AA. The laminated window glass 2 has an outer first glass layer 12 (which faces outward when installed), an inner second glass layer 14, and a polymer interlayer 16 of PVB (typically 0.76 mm thick). Figure 1 The shielding strip 6 shown in (a) comprises two shielding layers, one on surface 2 of the window glass and one on surface 4 of the window glass. A black, opaque enamel shielding layer 18 is printed on surface 2 of the outer first glass layer 12 (i.e., the non-exposed surface of the first glass layer 12, which is inside the laminate and faces the vehicle interior). The non-printed (i.e., transparent) area forms the first sensor window portion 15. A black, opaque enamel shielding layer 20 is printed on surface 4 of the second glass layer 14 (i.e., the surface of the inner glass layer 14 facing the vehicle interior when installed). Similarly, the non-printed area forms the second sensor window portion 17. The first sensor window portion 15 and the second sensor window portion 17 together form the sensor window 10 (e.g., for an ADAS camera) in the laminated window glass 2.

[0086] exist Figure 1 In this embodiment, the second sensor window portion 17 is larger than the first sensor window portion 15. This results in an offset 19 between the lower edges of the two sensor window portions and similarly an offset 21 between the upper edges. Offsets 19 and 21 are the differences in the vertical (i.e., y-axis) dimension between the upper and lower edges of the outer 15 and inner window portions 17 (once the window glass is installed, such as...). Figure 1 (as shown in (a)). Offsets 19 and 21 are at... Figure 1 The embodiments are basically the same, but may differ in other embodiments.

[0087] for Figure 1 In the embodiment shown, both glass layers are shaped by a drooping bend, and unexpectedly, the larger inner window portion 17 tends to cause the optical distortions from the surface 2 shielding layer 18 and the surface 4 shielding layer 20 to balance each other and reduce the overall or net optical distortion of the sensor window 10.

[0088] Figure 2 The illustration shows a laminated window glass 22 according to another embodiment of the present invention. The laminated window glass 22 is a windshield for a motor vehicle. The laminated window glass 22 comprises two glass layers laminated together by an interlayer of polymer, such as polyvinyl butyral (PVB). The laminated window glass 22 has a peripheral shielding strip 26 surrounding a transparent portion of the window glass 24. The shielding strip 26 is optically opaque and conceals multiple parts of the vehicle, and also provides protection for the adhesive against UV light.

[0089] Within the shielding strip 26, at the upper edge of the windshield (when mounted in a vehicle), are two optically clear Advanced Driver Assistance Systems (ADAS) camera sensor windows, including a left sensor window 30 and a right sensor window 32. The sensor windows are not covered by the enamel of the shielding strip 26. When mounted in a vehicle, sensor windows 30 and 32 allow one or more cameras to form an image viewed through the upper part of the windshield.

[0090] As in Figure 1 In this embodiment, due to the different heating rates of the black shielding strip 26 and the transparent portion of the window glass 24 and the transparent camera windows 30, 32, optical distortion may occur after the glass layer is heated / shaped around the transparent portion 28, near the edge of the shielding strip 26, and in the portion of the glass layer in the sensor windows 30, 32. The heating / shaping of the glass layer can be performed by drooping bending or pressing, and the degree and type of optical distortion can differ between these methods.

[0091] The masking strips in both embodiments comprise enamel formed by screen printing enamel ink onto a surface, curing / drying, and then firing the ink. The enamel may contain borosilicate glass frit and at least one inorganic pigment (e.g., containing iron and / or chromium).

[0092] Figure 3 A schematic diagram of a camera / sensor window, as used in the example, is shown. Figure 3 In each of (a), 3(b), and 3(c), the shielding strip 40 has a sensor window 42. Figure 3 In (a), the second sensor window portion 44 of surface 4, which is larger than the first sensor window portion of surface 2, has an offset of 5 mm at the top and sides (i.e., the sensor window portion of surface 4 is 5 mm larger than the sensor window portion of surface 2 at the top and sides) and an offset of 8 mm at the bottom. Figure 3 (b) contains, as in Figure 3 The larger offset surface 4 of (a) of the second sensor window portion also has serrated fades 46 at the bottom and top of the window portion. The serrated fades 46 are added to the top and bottom edges (rather than subtracted from them), making them more uniform with the surface. Figure 3 Compared to the arrangement in (b), the black printing can extend further towards the center of the sensor window. Other patterns can be used instead of the jagged pattern, such as spots, lines, or feathered edges. Figure 3 In (c), the second sensor window portion 44 of the larger surface 4 with a 5mm circumferential offset is located in the shielding frame 48 of the surface 4 within the shielding band 40, the shielding frame 48 including a high infrared reflectance enamel (with a higher IR reflectance than the rest of the shielding band on surface 4 and the IR reflectance of the enamel on surface 2).

[0093] Multiple variations of these camera / sensor window configurations are possible. For example, the sensor window portion of surface 4 can be smaller than the sensor window portion of surface 2. Furthermore, the offset does not need to be symmetrical and can be shifted, i.e., have different offsets from top to bottom, from side to side, or both.

[0094] Figure 9 The illustration shows some other designs for the sensor window portion, illustrating the designs of surface 2 (S2) (i.e., the first sensor window portion) and surface 4 (S4) (i.e., the second sensor window portion). Figure 9 (a) roughly as Figure 3 As shown in (a). Figure 9 (b) shows a portion of the S4 sensor window on one side, with a single lower bar on the S4. Figure 9 (c) and (e) show the "cap" or "U" configuration on the three sides of the S4, and Figure 9 (d) shows multiple stripes / blocks on S4.

[0095] like Figure 1 or Figure 2 The laminated window glass shown can typically be manufactured as follows: A flat glass substrate (e.g., 2.1 mm thick soda-lime float glass) is screen-printed with enamel ink using a screen and squeegee (using a screen that may have, for example, 50 to 120 lines / cm polyester screen, such as 77 or 100 lines / cm polyester screen) to form a screen-printed border, which is optionally dried by subjecting the substrate to infrared radiation from an infrared heater at a temperature below 300°C. Two printed glass substrates are then stacked to form an outer first glass layer 12 and an inner second glass layer 14, and the stacked substrates are bent. At this stage, a heat source is provided and bending can typically be performed by heating to a temperature of 570°C for more than 8 minutes, holding at this temperature for a period of 1 minute, and then bending at this temperature under any standard bending die or frame by pressure or sag bending. The substrates are separated and then, after cooling, laminated together using a PVB interlayer (approximately 0.76 mm thick).

[0096] Window glass can be laminated by, for example, pre-clamping with rollers or using vacuum rings applied to the edges of the first and second glass layers to degas the assembly of the glass layers and PVB interlayer. The first and second glass layers and the PVB interlayer are then laminated together in an autoclave at a pressure ranging from 6 to 14 bar and a temperature ranging from 110°C to 150°C.

[0097] The invention is further illustrated by the following examples, but is not limited thereto.

[0098] Example

[0099] In the example, black enamel (e.g., Johnson Matthey 1L530, Prince DV174100, and Prince DV17450, a high IR reflectance enamel) is used according to the method described above, and sensor window portions of different sizes and shapes are used in, for example... Figure 3 Laminated windows are manufactured on surfaces 2 and 4 shown. Another ink that has been tested is Johnson Matthey 1L4755-WF789P, which is a medium-performance ink.

[0100] Using a photometric system equivalent to the ISRA Vision AG standard system, the photometric power of multiple samples of each laminated window glass is measured horizontally and vertically at a 55-degree angle (converted to a 60-degree test angle for comparison). The system has a filter for defining the photometric power integration length (e.g., a 1 / 2 / 0 ISRA filter, equivalent to a 1mm / 1mm filter in the photometric power measurement system).

[0101] The light transmittance in the visible spectrum (380-780 nm) measured at the installation angle is at least 54%.

[0102] The average vertical optical power along the center line of each window is determined from top to bottom, and the results are shown in... Figures 4 to 8 In the diagram, the x-axis shows the measurement position in mm relative to the center of the window, with the top of the window on the left (x = negative) and the bottom of the window on the right (x = positive). The y-axis shows the optical power measured at each position in mdpt, but is converted to 60° as described above.

[0103] Example 1

[0104] This example uses inks that generate standard optical power levels. The results are as follows: Figure 4 As shown, the standard sensor window portions are located on surfaces 2 and 4. There is a relative S2 / S4 offset of 5 mm around the perimeter and 8 mm at the bottom (where the S4 window portion is larger). Line D shows the optical power generated on surface 2, which is negative, and line E shows the optical power generated on surface 4, which is also negative at the center of the window but positive at the top and bottom. Line F shows the net optical power, which, in absolute magnitude, decreases towards the top of the window, especially the bottom, but shows almost no improvement at the center. Figure 4 This demonstrates how balancing the opposing optical powers on the printed surfaces adjacent to each masking layer can reduce optical distortion relative to each individual layer. However, since the optical power generated on surface 2 is weaker than that on surface 4, optimal results have not yet been achieved.

[0105] Example 2

[0106] In this example, an enamel with high infrared reflectivity was used on surface 4, and the results were... Figure 5 The design of the windshield and sensor window portions is the same as in Example 1, but with a 5mm offset around the perimeter (S4 is approximately 5mm larger than S2). As mentioned above, the shielding layer on surface 4 uses a high IR reflectivity enamel (the enamel on surface 2 is the same as in Example 1, a standard enamel). Line D is the same as in Example 1. Line G shows the optical power produced on surface 4 by the enamel with high infrared reflectivity. Line H shows the net optical power in the window; this line is located near the x-axis, showing how much optical distortion has been reduced. By selecting a high infrared reflectivity ink for surface 4, the resulting distortion distribution is closer to the reverse side of surface 2 than in Example 1 (line D). Therefore, the optical distortion of the combined system is further reduced significantly. For comparison, line I shows the optical power of the unprinted glass through the baseline. It can be seen that the net optical power towards the bottom of the window is actually better than that of the unprinted glass, and towards the top it is close to the optical power of the unprinted glass.

[0107] Example 3

[0108] This example uses a different windshield than Examples 1 and 2. Like Example 1, standard inks were used, and the results are... Figure 6 The sensor window portion is designed the same as in Example 1, offset by 5mm around the perimeter and 8mm at the bottom. Line J shows the optical power generated on surface 2, and line K shows the optical power generated on surface 4. Line L shows the combined optical power. Although a different windshield design was used, the results show a similar effect to Example 1. Because the optical power on surface 4 (line K) has a larger absolute magnitude than that on surface 2 (line J), ​​the compensation effect is only partially achieved, i.e., towards the bottom of the windshield.

[0109] Example 4

[0110] This example uses the windshield from Example 3, and applies a high-infrared-reflectivity enamel to surface 4. The results are... Figure 7The design of the windshield and sensor window portions is the same as in Example 3, but with a 5mm offset around the edges (S4 is approximately 5mm larger than S2), and the shielding layer on surface 4 uses a high IR reflectivity enamel. Line J is the same as in Example 3, and line M shows the optical power achieved on surface 4 using the high IR reflectivity enamel. Note that line M is almost a mirror image of line J, mirrored with the x-axis. The net optical power is shown by line N and is significantly reduced. Again, this shows that if the sensor window portions and ink design are properly chosen, equal and opposite optical powers can be achieved in each individual layer, which almost cancel each other out after lamination. Line O again shows the baseline optical power used for comparison with unprinted glass. Optical distortion is greatly reduced and close to the optical power of unprinted glass.

[0111] Example 5

[0112] This example illustrates several methods for balancing optical distortion / optical power with the combination of sensor window design and enamel. The results are... Figure 8 As shown in the diagram, the design of the windshield and sensor window sections utilizes S4 "caps" (as shown in the diagram) around the three sides of the window section. Figure 9 (c) In this case, however (as in other examples) there is a 2-3mm offset around all four sides of S2 (S4 is approximately 5mm larger than S2 around S4). Sensor window designs are generally as follows: Figure 9 As shown in (c), line P indicates the optical power on surface 2 using standard enamel, line Q indicates the optical power on surface 2 using high infrared reflectivity enamel, and line T indicates the optical power on surface 4, again using high infrared reflectivity enamel. The windshield is manufactured using two different configurations: first, the sensor window portion on surface 4 is larger than the sensor window portion on surface 2 (line R); second, the sensor window portion on surface 2 is larger than the sensor window portion on surface 4 (line S). In both cases, the enamel has high infrared reflectivity. It can be seen that lines R and S both represent improvements over the individual layers (lines Q and T), but line R produces the best overall result.

[0113] In summary, this invention demonstrates that balancing the optical power distribution of the first and second glass layers provides a sensor window with significantly reduced overall optical distortion and optical power.

[0114] Reference number

[0115] 2-layer laminated window glass

[0116] 4. The transparent portion of the window glass

[0117] 6. Shelter belt

[0118] 8. The perimeter of the transparent part

[0119] 10 sensor (e.g., ADAS camera) window

[0120] 12 First (e.g., outer) glass layer

[0121] 14 Second (e.g., inner) glass layer

[0122] 15 First sensor window section

[0123] 16 polymer sandwich

[0124] 17 Second sensor window section

[0125] 18 Surface 2 Masking Layer

[0126] 19 Lower edge offset

[0127] 20 Surface 4 Masking Layer

[0128] 21 Upper edge offset

[0129] 22-layer laminated window glass

[0130] 24. The transparent portion of the window glass

[0131] 26. Shielding zone

[0132] 28. The perimeter of the transparent part

[0133] 30 Left sensor (e.g., ADAS camera) window

[0134] 32 Right sensor (e.g., ADAS camera) window

[0135] 40 shielding belt

[0136] 42 sensor windows

[0137] 44 Surface 4 Window Part Offset

[0138] 46 serrations fade out

[0139] 48. Shielding frames (e.g., high IR reflectivity)

Claims

1. A laminated window glass, comprising: A first glass layer having a first surface and a second surface, A second glass layer having a third and a fourth surface, At least one polymer layer located between the first glass layer and the second glass layer, A shielding strip surrounding at least a portion of the perimeter of a window pane, the shielding strip having at least one sensor window and including a first shielding layer and a second shielding layer. The first glass layer has a first shielding layer adhered to at least a portion of the periphery of the first surface or the second surface, the first shielding layer including at least one first sensor window portion having optical distortion of the first sensor window portion. The second glass layer has a second shielding layer adhered to at least a portion of the periphery of the third or fourth surface, the second shielding layer including at least one second sensor window portion having optical distortion of the second sensor window portion. The optical distortion of the first sensor window portion and the optical distortion of the second sensor window portion are each controlled, so that the absolute magnitude of the optical distortion of the sensor window is lower than the absolute magnitude of the optical distortion of the first sensor window and the optical distortion of the second sensor window. The first sensor window portion has an x-axis dimension and / or a y-axis dimension, and the second sensor window portion has an x-axis dimension and / or a y-axis dimension, wherein the x-axis dimension and / or y-axis dimension of the first sensor window portion are different from the x-axis dimension and / or y-axis dimension of the second sensor window portion. Wherein the x-axis dimension of the first sensor window portion is greater than the x-axis dimension of the second sensor window portion, and / or the y-axis dimension of the first sensor window portion is greater than the y-axis dimension of the second sensor window portion. The smaller window portion is positioned such that it is offset relative to the larger window portion at each end of the dimension, and The offset at one end of the y-axis dimension is different from the corresponding offset at the other end of the y-axis dimension. This allows for control of optical distortion in the first sensor window portion and optical distortion in the second sensor window portion.

2. The laminated window glass according to claim 1, wherein the shape of the first sensor window portion is different from the shape of the second sensor window portion, thereby controlling the optical distortion of the first sensor window portion and the optical distortion of the second sensor window portion.

3. The laminated window glass according to claim 1, wherein the shape of the first sensor window portion and / or the second sensor window portion is square, rectangular, trapezoidal, elliptical or circular.

4. The laminated window glass according to claim 1, wherein the first sensor window portion and / or the second sensor window portion are respectively partially or completely surrounded by the first shielding layer and / or the second shielding layer.

5. The laminated window glass according to claim 1, wherein at least a portion of the periphery of the first sensor window portion or the second sensor window portion is patterned.

6. The laminated window glass according to claim 5, wherein at least a portion of the periphery of the first sensor window portion or the second sensor window portion includes a spot, line, fade, or feathered edge.

7. The laminated window glass according to claim 5, wherein at least a portion of the periphery of the first sensor window portion or the second sensor window portion includes a serrated fade.

8. The laminated window glass of claim 1, wherein the first shielding layer and the second shielding layer are formed of materials with different emissivity or infrared reflectivity, thereby allowing control of optical distortion in the first sensor window portion and optical distortion in the second sensor window portion.

9. The laminated window glass according to claim 1, wherein at least a portion of the first shielding layer and / or the second shielding layer has an infrared reflectivity of 21% or higher in the region of wavelength range from 800 nm to 2250 nm.

10. The laminated window glass according to claim 1, wherein the first shielding layer and / or the second shielding layer comprises enamel, the enamel comprising glass frit and inorganic pigment, and wherein the inorganic pigment is selected from chromium-iron pigment, ferrite pigment, chromite pigment or ferrite / chromite pigment.

11. The laminated window glass of claim 10, wherein the enamel of the first shielding layer and / or the enamel of the second shielding layer are selected from low emissivity or low IR reflectivity enamel or high emissivity or high IR reflectivity enamel, thereby allowing control of optical distortion in the first sensor window portion and optical distortion in the second sensor window portion.

12. The laminated window glass of claim 1, wherein the periphery of the first sensor window portion or the second sensor window portion includes a shielding frame portion having a lower or higher IR reflectance than the shielding layer on the rest of the glass layer and / or a lower or higher IR reflectance than the shielding layer on another glass layer.

13. The laminated window glass of claim 12, wherein the periphery of the second sensor window portion includes the shielding frame portion.

14. The laminated window glass of claim 1, wherein the first sensor window portion and / or the second sensor window portion have optical distortion in the range of -405 to +405 millidiopters.

15. The laminated window glass according to claim 1, wherein the first sensor window portion and / or the second sensor window portion have optical distortion in the range of -310 to +310 millidiopters.

16. The laminated window glass of claim 1, wherein the first sensor window portion and / or the second sensor window portion have optical distortion in the range of -205 to +205 millidiopters.

17. The laminated window glass according to claim 1, wherein the first sensor window portion and / or the second sensor window portion have optical distortion in the range of -185 to +185 millidiopters.

18. The laminated window glass according to claim 1, wherein the first sensor window portion and / or the second sensor window portion have optical distortion in the range of -155 to +155 millidiopters.

19. The laminated window glass of claim 1, wherein the sensor window has optical distortion in the range of -195 to +195 millidiopters.

20. The laminated window glass of claim 1, wherein the sensor window has optical distortion in the range of -145 to +145 millidiopters.

21. A process for producing shaped laminated window glass, the process comprising, A first glass substrate having a first surface and a second surface, and a second glass substrate having a third surface and a fourth surface are provided. A first shielding layer is applied to at least a first portion of a first surface or a second surface of a first glass substrate, the first shielding layer including at least one first sensor window portion having controlled optical distortion of the first sensor window portion. A second shielding layer is applied to at least a first portion of a third or fourth surface of a second glass substrate, the second shielding layer including at least one second sensor window portion having controlled optical distortion of the second sensor window portion. At least one polymer layer is placed between the first glass substrate and the second glass substrate, and Laminating a first glass substrate, a polymer layer, and a second glass substrate, Therefore, by controlling the optical distortion of the first sensor window portion and the optical distortion of the second sensor window portion, the absolute magnitude of the optical distortion of the sensor window is lower than the absolute magnitude of the optical distortion of the first sensor window and the optical distortion of the second sensor window. The first sensor window portion has an x-axis dimension and / or a y-axis dimension, and the second sensor window portion has an x-axis dimension and / or a y-axis dimension, wherein the x-axis dimension and / or y-axis dimension of the first sensor window portion are different from the x-axis dimension and / or y-axis dimension of the second sensor window portion. Wherein the x-axis dimension of the first sensor window portion is greater than the x-axis dimension of the second sensor window portion, and / or the y-axis dimension of the first sensor window portion is greater than the y-axis dimension of the second sensor window portion. The smaller window portion is positioned such that it is offset relative to the larger window portion at each end of the dimension, and The offset at one end of the y-axis dimension is different from the corresponding offset at the other end of the y-axis dimension. This allows for control of optical distortion in the first sensor window portion and optical distortion in the second sensor window portion.

22. The process according to claim 21, further comprising: The first glass substrate and the second glass substrate are formed by heating the first glass substrate and the second glass substrate to a temperature above 570°C.

23. The process according to claim 21, wherein the shape of the first sensor window portion is different from the shape of the second sensor window portion, thereby controlling the optical distortion of the first sensor window portion and the optical distortion of the second sensor window portion.

24. The process according to claim 21, wherein the shape of the first sensor window portion and / or the second sensor window portion is square, rectangular, trapezoidal, elliptical or circular.

25. The process of claim 21, wherein the first sensor window portion and / or the second sensor window portion are respectively partially or completely surrounded by the first shielding layer and / or the second shielding layer.

26. The process of claim 21, wherein at least a portion of the periphery of the first sensor window portion or the second sensor window portion is patterned.

27. The process of claim 26, wherein at least a portion of the periphery of the first sensor window portion or the second sensor window portion includes a spot, line, fade, or feathered edge.

28. The process of claim 26, wherein at least a portion of the periphery of the first sensor window portion or the second sensor window portion includes a serrated fade-out.

29. The process of claim 21, wherein the first and second shielding layers are formed of materials with different emissivity or infrared reflectivity, thereby allowing control of optical distortion in the first and second sensor window portions.

30. The process of claim 21, wherein at least a portion of the first shielding layer and / or the second shielding layer has an infrared reflectivity of 21% or higher in the region of wavelength range from 800 nm to 2250 nm.

31. The process of claim 21, wherein the first shielding layer and / or the second shielding layer comprises enamel, the enamel comprising glass frit and inorganic pigment, and wherein the inorganic pigment is selected from chromium-iron pigment, ferrite pigment, chromite pigment or ferrite / chromite pigment.

32. The process of claim 31, wherein the enamel of the first shielding layer and / or the enamel of the second shielding layer are selected from low emissivity or low IR reflectivity enamel or high emissivity or high IR reflectivity enamel, thereby allowing control of optical distortion in the first sensor window portion and optical distortion in the second sensor window portion.

33. The process of claim 21, wherein the periphery of the first sensor window portion or the second sensor window portion includes a shielding frame portion having a lower or higher IR reflectance than the shielding layer on the rest of the glass substrate and / or a lower or higher IR reflectance than the shielding layer on another glass substrate.

34. The process of claim 33, wherein the periphery of the second sensor window portion includes the shielding frame portion.

35. The process of claim 21, wherein the first sensor window portion and / or the second sensor window portion have optical distortion in the range of -405 to +405 millidiopters.

36. The process of claim 21, wherein the first sensor window portion and / or the second sensor window portion have optical distortion in the range of -310 to +310 millidiopters.

37. The process of claim 21, wherein the first sensor window portion and / or the second sensor window portion have optical distortion in the range of -205 to +205 millidiopters.

38. The process of claim 21, wherein the first sensor window portion and / or the second sensor window portion have optical distortion in the range of -185 to +185 millidiopters.

39. The process of claim 21, wherein the first sensor window portion and / or the second sensor window portion have optical distortion in the range of -155 to +155 millidiopters.

40. The process of claim 21, wherein the sensor window has optical distortion in the range of -195 to +195 millidiopters.

41. The process of claim 21, wherein the sensor window has optical distortion in the range of -145 to +145 millidiopters.

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