Thermoforming windshield stack with integrated formable mold

Abstract

Fabricating a pre-molded stack having one or more lenses mountable on a curved substrate, such as a vehicle windshield, includes placing a moldable stack having one or more lenses and an adhesive layer on a mold, applying heat and pressure to the moldable stack, the method includes molding a mold to prepare a pre-molded stack having one or more lenses from the moldable stack, and removing the pre-molded stack from the mold. The pre-molded stack may have a composite curvature that may match a curvature of the curved substrate. The mold may be formed using three-dimensional shape data obtained from a curved substrate (e.g., by optically scanning the curved substrate).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is a continuation-in-part of U.S. Patent Application No. 16 / 778,928, filed on January 31, 2020, entitled “Thermoform Windshield Stack With Integrated Formable Mold,” which is related to and claims the benefit of U.S. Provisional Application No. 62 / 799,880, filed on February 1, 2019, entitled “Thermoform Windshield Stack With Integrated Formable Mold,” the entire contents of each of which are expressly incorporated herein by reference.

[0003] Statement: Federally Sponsored Research / Development

[0004] not applicable Technical Field

[0005] The present disclosure relates generally to transparent coverings for windows, and more particularly to transparent coverings having a plurality of lenses stacked one on top of another and bonded together by an adhesive. Background Art

[0006] Securing a transparent lens to a curved substrate such as a windshield (also known as a windshield) can have a variety of benefits. Such a covering can have the following functions: protection from pitting and cracking, tinting (e.g., for privacy), thermal insulation, blocking ultraviolet (UV) radiation, and / or decoration. Such a stack of transparent lenses can facilitate easy tearing when the outermost lens becomes dirty and obstructs the driver's field of view (such as may occur in an off-road vehicle).

[0007] While the surface of a typical windshield generally exhibits a compound curvature, the transparent lens itself can be flat (e.g., in the case of polyethylene terephthalate (PET) films manufactured in a roll-to-roll process). To install a flat film onto a compound curved windshield surface, the film is formed over the windshield, for example, by laying the film onto the windshield and applying heat to the uppermost surface to shrink or stretch the film so that it assumes the shape of the windshield. However, this process can result in uneven or overheating of the film, which can cause optical distortion of the film and can create areas where the film does not adequately adhere to the windshield. In addition, attempts by the installer to apply pressure to the film with a card or scraper can result in permanent scratching of the visible surface during installation. Summary of the invention

[0008] The present disclosure contemplates various systems and methods for overcoming the shortcomings of the related art described above. One aspect of an embodiment of the present disclosure is a method for mounting a stack having two or more lenses on a curved substrate. The method may include placing a moldable cover on a curved substrate, the moldable cover including a stack having two or more lenses, an adhesive layer between each pair of adjacent lenses in the two or more lenses, and a sacrificial layer disposed on the outermost lens of the stack, the sacrificial layer including a sacrificial lens and a sacrificial adhesive between the sacrificial lens and the outermost lens of the stack. The method may include applying heat and pressure to the sacrificial layer, and peeling off the sacrificial layer to expose the stack having two or more lenses.

[0009] The curved substrate may be a composite curved substrate. The curved substrate may be a windshield.

[0010] The sacrificial layer may be more heat resistant than the outermost lens of the stack.

[0011] The sacrificial layer may be less scratch resistant than the outermost lens of the stack.

[0012] The sacrificial lens may include a biaxially oriented polyethylene terephthalate film. The biaxially oriented polyethylene terephthalate film may withstand temperatures between room temperature and 220°C for two hours.

[0013] The sacrificial lens may include an opaque polyester film.The outermost lens of the stack may include a transparent polyethylene terephthalate film.

[0014] Another aspect of the disclosed embodiments is a moldable covering that can be fixed to a curved substrate, which moldable covering may include a stack of two or more lenses, an adhesive layer between each pair of adjacent lenses in the two or more lenses, and a sacrificial layer disposed on the outermost lens of the stack, the sacrificial layer including a sacrificial lens and a sacrificial adhesive between the sacrificial lens and the outermost lens of the stack, the sacrificial layer being more heat resistant than the outermost lens of the stack.

[0015] The sacrificial lens may include a biaxially oriented polyethylene terephthalate film. The biaxially oriented polyethylene terephthalate film may withstand temperatures between room temperature and 220°C for two hours.

[0016] The sacrificial lens may include an opaque polyester film.The outermost lens of the stack may include a transparent polyethylene terephthalate film.

[0017] Another aspect of an embodiment of the present disclosure is a moldable cover that can be fixed to a curved substrate. The moldable cover can include a stack of two or more lenses, an adhesive layer between each pair of adjacent lenses in the two or more lenses, and a sacrificial layer disposed on the outermost lens of the stack, the sacrificial layer including a sacrificial lens and a sacrificial adhesive between the sacrificial lens and the outermost lens of the stack, the sacrificial layer being less scratch resistant than the outermost lens of the stack.

[0018] The sacrificial lens may include a biaxially oriented polyethylene terephthalate film. The biaxially oriented polyethylene terephthalate film may withstand temperatures between room temperature and 220°C for two hours.

[0019] The sacrificial lens may include an opaque polyester film.The outermost lens of the stack may include a transparent polyethylene terephthalate film.

[0020] Another aspect of an embodiment of the present disclosure is a method of making a pre-molded stack of lenses that can be mounted on a curved substrate. The method may include placing a moldable stack of lenses on a mold, the moldable stack of lenses including two or more lenses and an adhesive layer between each pair of adjacent lenses of the two or more lenses. The method may further include: applying heat and pressure to the moldable stack of lenses to prepare a pre-molded stack of lenses from the moldable stack of lenses, and removing the pre-molded stack of lenses from the mold.

[0021] Another aspect of an embodiment of the present disclosure is a method for manufacturing a pre-molded stack having one or more lenses that can be mounted on a curved substrate. The method may include placing a moldable stack having one or more lenses on a mold, the moldable stack including one or more lenses and one or more adhesive layers respectively disposed thereon. The method may further include: applying heat and pressure to the moldable stack to prepare a pre-molded stack having one or more lenses from the moldable stack having one or more lenses, and removing the pre-molded stack having one or more lenses from the mold.

[0022] Either of the foregoing two methods may include obtaining three-dimensional shape data from a curved substrate and forming a mold using the three-dimensional shape data. The obtaining of the three-dimensional shape data may include optically scanning the curved substrate. The curved substrate and the mold may be the same type of windshield. The mold may include a compound curved surface.

[0023] Applying heat and pressure may include arranging a plurality of heaters on a frame positioned to direct the heaters toward the moldable stack. Applying heat and pressure may include applying pressure to the moldable stack with one or more rollers.

[0024] The moldable stack may include a sacrificial layer disposed on the outermost lens of the stack. The sacrificial layer may include a sacrificial lens and a sacrificial adhesive between the sacrificial lens and the outermost lens of the stack. The sacrificial layer may be more heat resistant than the outermost lens of the stack. The sacrificial layer may be less scratch resistant than the outermost lens of the stack. The sacrificial lens may include a biaxially oriented polyethylene terephthalate film. The biaxially oriented polyethylene terephthalate film may withstand temperatures between room temperature and 220° C. for two hours. The sacrificial lens may include an opaque polyester film. The outermost lens of the stack may include a transparent polyethylene terephthalate film.

[0025] Another aspect of an embodiment of the present disclosure is a pre-molded stack having two or more lenses that can be mounted on a curved substrate. The pre-molded stack can include a stack having two or more lenses and an adhesive layer between each pair of adjacent lenses in the two or more lenses. The pre-molded stack can have a compound curvature.

[0026] Each of the two or more lenses may include a biaxially oriented polyethylene terephthalate film. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] These and other features and advantages of the various embodiments disclosed herein will be better understood by referring to the following description and drawings, wherein like reference numerals refer to like parts throughout, and wherein:

[0028] Figure 1 is a schematic side view of a moldable cover according to an embodiment of the present disclosure;

[0029] Figure 2 shows a moldable covering placed on a windshield at the beginning of a process of applying heat and pressure to a sacrificial layer of the moldable covering;

[0030] Figure 3 shows a moldable covering on a windshield at the end of the process of applying heat and pressure;

[0031] Figure 4 shows a moldable covering on a windshield as the sacrificial layer is peeled off to reveal a stack of transparent lenses;

[0032] Figure 5 A stack of clear lenses trimmed to fit behind a windshield is shown;

[0033] Figure 6 An exemplary operation flow according to an embodiment of the present disclosure is shown;

[0034] Figure 7 A moldable stack having one or more lenses according to another embodiment of the present disclosure is shown, as well as a mold for preparing a pre-molded stack of lenses and a frame for positioning multiple heaters and / or rollers;

[0035] Figure 8 shows an exemplary operation flow according to another embodiment of the present disclosure; and

[0036] Fig. 9 Shows Figure 8 An exemplary sub-operation flow of step 840 in FIG. DETAILED DESCRIPTION

[0037] The present disclosure includes various embodiments of a moldable cover having a stack of two or more lenses and methods for mounting the same, as well as various embodiments of a pre-molded lens stack and methods for making the same. The detailed description below, in conjunction with the accompanying drawings, is intended as a description of several currently considered embodiments and is not intended to represent the only form in which the disclosed invention may be developed or utilized. This specification describes the functions and features of the disclosed invention in conjunction with the described embodiments. However, it should be understood that the same or equivalent functions may be achieved by other embodiments that are also encompassed within the scope of the present disclosure. It should also be understood that relational terms such as first and second are used only to distinguish one entity from another entity without necessarily requiring or implying any actual such sequential relationship between these entities.

[0038] Figure 1 1 is a schematic side view of a moldable cover 100 according to an embodiment of the present disclosure. As part of the process of mounting a stack having lenses 110a, 110b, ... 110n (collectively referred to as lenses 110), the moldable cover 100 can be secured to a curved substrate 10 such as a windshield. The mounted stack of lenses 110 can provide the substrate 10 with protection, tinting, thermal insulation, blocking of ultraviolet (UV) radiation, decoration, and / or the ability to peel off and discard the outermost layer 110n (and any newly exposed layer 110 thereafter) as desired during the life of the article. In addition to the lenses 110, the moldable cover 100 can include adhesive layers 120a, 120b, ... 120n (collectively referred to as adhesive layers 120) disposed on each lens 110, respectively, such that the adhesive layer 120 is interposed between each pair of adjacent lenses 110 in the stack. On the outermost lenses 110n of the stack of lenses 110, a sacrificial layer 130 can be provided to achieve an improved process of mounting the stack of lenses 110 to the substrate 10. The sacrificial layer 130 may include a sacrificial lens 132 and a sacrificial adhesive 134 between the sacrificial lens 132 and the outermost lens 110n of the lens 110 stack. When the lens 110 stack is mounted, heat and pressure may be applied to the sacrificial layer 130 to conform the lens 110 stack to the shape of the curved substrate 10. Thereafter, the sacrificial layer 130 may be peeled off to expose a final product 140 including the mounted lens 110.

[0039] If the lens 110 stack is simply overmolded onto the curved substrate 10 without the sacrificial layer 130, the process may result in uneven heating or overheating as described above, and may permanently scratch the outermost lens 110n with a card or scraper. The inventors have discovered that these problems primarily stem from the lack of a female mold cavity to apply pressure when the lens 110 stack conforms to the convex surface presented by the curved substrate 10. As a result, when the installer attempts to mold the lens 110 stack to the curved substrate 10, neither heat nor pressure can be evenly distributed, resulting in the problems described. By providing the sacrificial layer 130 as the missing female mold cavity, the disclosed moldable cover 100 can overcome these deficiencies in at least two ways. First, the sacrificial layer 130 allows the installer to apply heat and pressure without worrying about scratching or otherwise damaging the final product. The sacrificial layer 130 can be discarded alone with any surface damage, while the outermost lens 110n of the lens 110 stack located thereunder remains flawless. Second, when heat and pressure are applied to the lens 110 stack through the sacrificial layer 130 interposed therebetween, the sacrificial layer 130 can be used to distribute the heat and pressure over a larger area, so that when the sacrificial layer 130 and the lens 110 stack located thereunder are conformed together to the shape of the curved substrate 10, the heat and pressure can be applied more evenly.

[0040] Lens 110 may include a transparent polyethylene terephthalate (PET) film, such as biaxially oriented polyethylene terephthalate (BoPET), and may be made from a polyester film sheet sold by DuPont under the registered trademark Mylar. The thickness of each lens 110 may be between 0.5 mil and 7 mils (1 mil is 0.001"), for example, 2 mils. Even after the adhesive material of adhesive layer 120 is applied to the 2 mil thick lens 110, since adhesive layer 120 has only a nominal thickness, the combined thickness of the 2 mil thick lens 110 and adhesive layer 120 may still be 2 mils.

[0041] As described in U.S. Pat. No. 6,536,045, entitled "Tear-off Optical Stack Having Peripheral Seal Mount," issued to Wilson on Mar. 25, 2003, the entire contents of which are expressly incorporated herein by reference, an adhesive for adhesive layer 120 may be applied to selected areas, for example, about the perimeter of moldable cover 100. Adhesive layer 120 may be made of an optically clear, low-tack material, and may include a water-based, acrylic, optically clear adhesive or an oil-based, clear adhesive. Adhesive layer 120a used to secure moldable cover 100 to substrate 10 may be the same as or different (e.g., stronger) than adhesive layer 120b, ... 120n, etc., between each pair of adjacent lenses 110 in the stack. For example, a stronger adhesive may be used in situations where a single lens 110 is torn off without removing the entire stack of lenses 110 from substrate 10 during use. Along the same lines, the adhesive used for adhesive layers 120b, ... 120n between each pair of adjacent lenses 110 can be stronger than the sacrificial adhesive 134 used for sacrificial layer 130, so that sacrificial layer 130 can be torn off without removing the outermost lens 110n from the stack of lenses 110. Sacrificial adhesive 134 can similarly be a low-viscosity material and can include a water-based acrylic optically clear adhesive or an oil-based transparent adhesive. However, in the case of sacrificial adhesive 134, since sacrificial adhesive 134 is removed in the final product 140, it can also be replaced with an opaque adhesive.

[0042] The lenses 110 may be optimized for scratch resistance and / or UV radiation blocking (absorbing or reflecting). For example, the outer side of each lens 110 may be coated with a coating (e.g., silicone acrylate oligomer and / or acrylated polyurethane polyol) by deposition, spraying, lamination or other means, which optimizes scratch resistance and / or UV radiation blocking properties, depending on the desired properties for the final product 140. Since the sacrificial layer 130 will not be present after installation is completed, these properties can be relaxed in the production of the sacrificial layer 130. Thus, for example, the sacrificial layer 130 may be less scratch resistant than the outermost lens 120n of the lens 120 stack. At the same time, the heat resistance of the sacrificial layer 130 may be optimized, for example, by applying a coating (e.g., silicone acrylate oligomer and / or acrylated polyurethane polyol) that optimizes heat resistance, because the sacrificial layer 130 can be directly heated as part of the process of thermoforming the moldable cover 100 into the shape of the curved substrate 10. This heat resistance may be relaxed in the stack of lenses 100 located therebelow, since these lenses may only be heated indirectly through the sacrificial layer 130. Thus, for example, the sacrificial layer 130 may be more heat resistant than the outermost lens 110n of the stack of lenses 100.

[0043] The sacrificial layer 130 can be made of high temperature PET, for example, PET that can withstand temperatures between room temperature and 220° C. for two hours (e.g., without deterioration). The high temperature PET can be a transparent BoPET that enables viewing of the lens 110 stack located thereunder during the molding process, and can be, for example, a polyester film sold by Mitsubishi Polyester Film Group under the trade name Hostaphan RBB. Such a high temperature BoPET may be preferred when hot air is used to heat the sacrificial layer 130 during the molding process. Alternatively, the sacrificial layer 130 can be made of an opaque (e.g., white) polyester film, such as a polyester film sold by Mitsubishi Polyester Film Group under the trade name Hostaphan WIN. Such an opaque polyester film can provide increased thermal uniformity when an infrared heater is used to heat the sacrificial layer 130 during the molding process.

[0044] While the sacrificial layer 130 (e.g., sacrificial lens 132 and / or sacrificial adhesive 134) can be optimized to withstand the heat of the installation process and evenly distribute heat and pressure to the lens stack 110 located thereunder, the sacrificial layer 130 generally does not have to meet the more stringent performance standards of the lens stack 110 located thereunder. For example, the lens stack can be designed to meet federal standards for visible light transmission (e.g., 70%) as set forth, for example, in American National Standards Institute (ANSI) standards Z26.1-1966 and Z26.1a-1969, as well as scratch resistance (e.g., by windshield wipers) as described above, and / or absorb or reflect UV light to protect the lens 110 from sunlight damage. By relaxing these requirements on the sacrificial layer 130 while providing a more robust surface for worry-free application of heat and pressure during installation, the moldable cover 100 enables the lens stack 110 to be installed in a more efficient method. With sacrificial layer 130 as a concave mold cavity, the layers of lens 110 and adhesive 120 will be better held, formed and cured onto curved substrate 10 and will never be scratched during the mounting process.

[0045] Figure 2 The moldable cover 100 is shown placed on an automotive windshield 20 at the beginning of the process of applying heat and pressure to the sacrificial layer 130 of the moldable cover 100, with the windshield serving as the substrate 10. For example, as described in U.S. Pat. No. 9,295,297 to Wilson, entitled “Adhesive Mountable Stack of Removable Layers,” issued on Mar. 29, 2016 (see U.S. Pat. No. 9,295,297). Figure 1 ), the entire contents of which are expressly incorporated herein by reference. Alternatively, for example, as described in U.S. Patent No. 9,128,545 to Wilson, entitled “Touch Screen Shield,” issued on September 8, 2015, the entire contents of which are expressly incorporated herein by reference. Since the moldable covering 100 can be flat (e.g., manufactured by a roll-to-roll process), the moldable covering 100 may not initially conform to the curved shape of the windshield, thereby forming larger or smaller bonding areas and air pockets / bubbles between the moldable covering 100 and the windshield. Therefore, in order to make the moldable covering 100 conform to the shape of the windshield, a heater 30 such as a hot air source (e.g., a heat gun or a blow dryer) or an infrared heater can be used to apply heat and pressure. At the same time, pressure can be applied to the moldable covering 100 using a card or a squeegee. When the installer heats and presses down the sacrificial layer 130 of the moldable cover 100, the sacrificial layer 130 can shrink and stretch to assume a contour corresponding to the curved substrate 10 (windshield), with the lens 110 stack located between the sacrificial layer and the curved substrate. In this way, the sacrificial layer 130 can be used as a concave mold cavity to thermoform the lens 110 stack located thereunder into the shape of the windshield, evenly distributing heat and pressure to shrink and stretch the lens 110 into the correct shape and curing the adhesive layer 120.

[0046] Figure 3 The moldable cover 100 on the windshield is shown at the end of the process of applying heat and pressure. At this stage, the moldable cover 100 including the sacrificial layer 130 and the lens 110 located thereunder is molded to the curved shape of the windshield without air pockets / bubbles. The upper surface of the sacrificial layer 130 may have various scratches and other imperfections caused by the installer applying pressure to the moldable cover 100 using a scraper or card. However, the lens 110 located thereunder is not affected because it is protected by the sacrificial layer 130.

[0047] Figure 4 The moldable cover 100 on the windshield is shown when the sacrificial layer 130 is peeled off to reveal the transparent lens 110 stack. Remaining on the windshield is the final product 140 including the lens 110 stack and the adhesive layer 120 (see Figure 1 ). The final product 140 may meet the performance standards as described above, including federal standards for visible light transmittance (e.g., 70%) and scratch resistance and / or UV absorption or blocking properties. The lenses 110 of the final product 140 may conform precisely to the shape of the windshield and may be free of defects even on the outermost lenses 110n. Only the peeled sacrificial layer 130 may be discarded.

[0048] Figure 5 The final product 140 including the stack of transparent lenses 110 is shown after the stack of transparent lenses 110 has been trimmed to fit a windshield as substrate 10. The stack of transparent lenses 110 may be trimmed using a tool such as a box cutter or a utility knife with a stainless steel blade (carbon blades may damage the windshield). Figure 5 As shown, trimming can be performed after the sacrificial layer 130 has been removed from the moldable cover 100, so that only the exposed final product 140 is trimmed. Figure 3 As shown, once the moldable cover 100 has been conformed to the shape of the windshield, it can be trimmed before removing the sacrificial layer 130. In either case, the resulting trimmed final product 140 can be effectively invisible because the trimmed final product 140 matches the shape of the underlying windshield (although the trimmed final product can change the color of the windshield, as in the case of window tinting).

[0049] Figure 6 An exemplary operation flow according to an embodiment of the present disclosure is shown. Figure 6 The operation process can be used as an installation including Figure 1 First, the moldable cover 100 including both the final product 140 and the sacrificial layer 130 may be placed on a substrate such as Figure 2 The moldable cover 100 is formed on a curved substrate 10 such as a windshield of an automobile 20 as shown (step 610), wherein the adhesive layer 120a is on the windshield and the sacrificial layer 130 is facing away from the windshield. For easier installation, the moldable cover 100 can be rough cut (e.g., using an electric film cutter) to a position that does not extend too far outside the windshield. The operation flow can continue, such as in conjunction with Figure 2 and Figure 3 As described, heat and pressure are applied to the sacrificial layer 130 of the moldable cover 100 to thermoform the moldable cover 100 into the curved shape of the windshield (step 620). After cooling the moldable cover 100, the operation flow may end by peeling off the sacrificial layer 130 to expose the bonded Figure 4 The final product 140 (step 630) and the like are combined Figure 5 The final trimming (step 640) is described above. Figure 6 Steps 630 and 640 may be performed in the order shown or in reverse order. At this point, the final product 140 including the stack of lenses 110 is uniformly formed and secured to the windshield surface.

[0050] As described above, several aspects of the disclosed subject matter can produce a moldable covering 100 that includes a stack of lenses 110 that is molded in-situ on an end user's vehicle windshield or other curved substrate 10. To this end, the moldable covering 100 can include a sacrificial layer 130 that protects the stack of lenses 110 located thereunder and acts as a concave mold cavity, allowing an installer to easily and efficiently mold the stack of lenses 110 using common equipment (e.g., a blower and card) without the risk of uneven heating or damage to the lenses 110. While these aspects can be very beneficial to users who wish to install the stack of lenses 110 themselves with minimal risk, as described above, in some cases it may be desirable to further simplify the installation process. For example, a user may be unable or unwilling (or simply lack the confidence) to apply the necessary heat and pressure to mold the moldable covering 100 to the shape of his / her windshield 10 ( Figure 6 Step 620 of the present invention) or subsequently trimming the moldable covering ( Figure 6 640). Thus, to further ease the burden on the installer, additional aspects of the disclosed subject matter involve manufacturing a pre-molded stack of lenses 110 that is already molded to the shape of a vehicle windshield or other curved substrate 10 (and optionally trimmed). The installer can simply apply the pre-molded stack of lenses 110 to the curved substrate 10 (e.g., by exposing and / or activating the adhesive layer 120a and placing the stack of lenses 110 on the curved substrate 10) without having to worry about molding and / or trimming the lenses 110 to accommodate these aspects of the curved substrate 10.

[0051] See also Figure 1 and Figure 7 , a pre-molded stack of lenses 110 can be prepared from a moldable stack 700, which can be Figure 1 The moldable cover 100 shown or the unmolded final product 140 thereof described previously (i.e., the moldable cover 100 but without the sacrificial layer 130) is the same. That is, as described above with respect to the moldable cover 100, the moldable stack 700 may include two or more lenses 110 and a bonding layer 120 between each pair of adjacent lenses of the two or more lenses 110. (It should also be noted that Figure 1 The final product 140 in FIG. 1 may also represent a pre-molded stack of lenses 110, i.e., a moldable stack 700 that has undergone the deformations described herein. As described in more detail below, the moldable stack 700 may typically be specialized molded using specialized equipment and a certain degree of expertise to accommodate the curved substrate 10, thereby reducing the risk of uneven heating / pressure or scratching of the outermost lenses 110n. Therefore, the sacrificial layer 130 described above may typically be omitted. However, it is also contemplated that the sacrificial layer 130 may be included, so that the moldable stack 700 and Figure 1The moldable coverings 100 shown are identical.

[0052] See also Figure 7 , the moldable stack 700 can be placed on a mold 40 of an appropriate shape, particularly a mold 40 that matches the curvature (usually a compound curvature) of a vehicle windshield or other substrate 10 on which the pre-molded stack of lenses 110 will ultimately be mounted. The mold 40 can be used as a lower (convex) mold and can include a compound curved surface. For example, the mold 40 can be a windshield of the same type (e.g., model, shape, size) as the substrate 10 on which the pre-molded stack of lenses 110 will be mounted. In this regard, the manufacturer of the pre-molded stack of lenses 110 can keep a variety of windshields currently available on the market to use as corresponding molds 40. When ordering a pre-molded stack of lenses 110, the order can include an indication of the type of windshield to which the pre-molded stack of lenses 110 is to be adapted. The moldable stack 700 can then be molded into a pre-molded stack of lenses 110 using the same type of windshield as the mold 40. Alternatively, the mold 40 may be formed using three-dimensional shape data of a windshield or other curved substrate 10 on which the pre-molded stack of lenses 110 will be mounted. For example, the curved substrate 10 may be optically scanned to obtain three-dimensional shape data such as a polygonal model (e.g., a wireframe model), and the obtained three-dimensional shape data may be used to form the mold 40 to match the substrate 10. In this way, the mold 40 may be custom-shaped to precisely match the customer's windshield.

[0053] Various techniques may be used to evenly apply heat and pressure to moldable stack 700 while it is positioned on mold 40 . Figure 7 The use of a frame 50 (e.g., an aluminum truss or other lightweight support structure) is shown, which can be disposed adjacent to the mold 40 and can support a plurality of heaters 60 for heating the moldable stack 700. The heaters 70 (e.g., a hot air source and / or an infrared heater) can be disposed on the frame 50 and directed toward the moldable stack 700. For example, it is contemplated that the frame 50 can define a grid of attachment points, such as can be disposed along the horizontal and vertical bars that form the exemplary frame 50 shown, and the heaters 60 can be freely attached to the frame 50 so as to be evenly spaced above the moldable stack 700 as desired. The precise positioning of the heaters 60 can be adjusted as desired, for example, depending on the size and shape of the mold 40. While the moldable stack 700 is being heated by the heaters 60, the moldable stack 700 can be pressed by one or more rollers 70, which can also be attached to the frame 50, such as on one or more tracks and / or pivot points. Roller 70 may be made of high density foam and may generally include a pair of rollers 70 that press down on moldable stack 700 in the middle of moldable stack 700 and move away from each other (along the Figure 710 (in the direction of the arrow in FIG. 1 ) to press the moldable stack 700 downwardly against the mold 40 while allowing the material of the lens 110 to deform outwardly.

[0054] Figure 8 An exemplary operation flow according to another embodiment of the present disclosure is shown, and Fig. 9 Shows Figure 8 An exemplary sub-operation flow of step 840 in FIG. Figure 8 and Fig. 9 The operational flow may be used as an exemplary method for manufacturing a pre-molded stack of lenses 110 that can be mounted on a curved substrate 10. The operational flow may begin by obtaining three-dimensional shape data associated with the curved substrate 10 on which the pre-molded stack of lenses 110 will eventually be mounted (e.g., obtained by optically scanning the substrate 10) (step 810), and using the three-dimensional shape data to form a mold 40 (see FIG. 1 ). Figure 7 )(Step 820). However, if mold 40 is preformed, such as in the case of using various known windshield types as mold 40 as described above, steps 810 and 820 may be omitted. In this case, mold 40 may simply be selected based on the specific curved substrate 10 to which the pre-molded stack of lenses 110 is to be mounted. In either case, the operational flow may continue with the step of placing moldable stack 700 (with lenses 110) on mold 40 (Step 830). As described above, moldable stack 700 may be formed with Figure 1 The moldable cover 100 shown is the same, or the sacrificial layer 130 may be omitted.

[0055] Once the moldable stack 700 is located on the mold 40, Figure 8 The operational flow may continue with the step of applying heat and pressure to moldable stack 700 to prepare a pre-molded stack of lens 110 (step 840). In some cases, the process of applying heat and pressure may be performed in accordance with the above combined method. Figures 2 to 5 The same process is performed in exactly the same manner, except that mold 40 is used instead of the actual substrate 10 to which the pre-molded stack of lenses 110 will eventually be mounted. It may also be advantageous for the manufacturer of the pre-molded stack of lenses 110 to have the moldable stack 700 include a sacrificial layer 130, using a simple hand-held heat source and applying pressure using a scraper or card. However, it is preferred that specialized equipment can be used to ensure uniform heating and safe application of pressure without scratching the outermost lenses 110, thereby eliminating the need for a sacrificial layer 130. See, for example, Fig. 9 The sub-process can apply heat and pressure by: Figure 7The heater 60 is shown arranged on the frame 50 to direct the heater 60 toward the moldable stack 700 (step 842), and the moldable stack 700 is further pressed with one or more rollers 70 (step 844). In this way, heat and pressure can be uniformly applied to the moldable stack 700 to promote the desired shrinkage and stretching of the lens 110 and the curing of the adhesive layer 120.

[0056] After sufficient heat and pressure have been applied to conform moldable stack 700 to the shape of mold 40, typically after cooling and as described above in conjunction with Figure 5 After trimming the excess material around the mold 40 as described (and stripping the sacrificial layer 130, if applicable), the resulting pre-molded stack of lenses 110 may be removed from the mold 40 (step 850). The pre-molded stack of lenses 110 may then be shipped or otherwise delivered to a customer who may install it on his / her own windshield or other curved substrate 10 without difficulty (step 860). For example, during delivery, a release liner or backing film may be provided on the innermost adhesive layer 120a of the pre-molded stack of lenses 110, or the adhesive layer 120a may be otherwise inactive. The customer may simply remove the release liner and place the lens 110 stack on his / her windshield 10, or may simply place the lens 110 stack on the windshield 10 and activate the adhesive layer 120a (e.g., in the case of a pressure sensitive adhesive, pressing the lens 110 stack against the windshield 10). Because the lens 110 stack is already pre-molded (and optionally pre-trimmed) to fit the windshield 10 , the customer does not need to be concerned with the process of molding the lenses 110 , and no specialized knowledge or special equipment is required.

[0057] Figure 1 The example of can represent a moldable cover 100, and also can represent a moldable stack 700 (or a pre-molded stack after deformation), where three lenses 110 are shown. However, it is contemplated that the moldable cover 100, moldable stack 700, or pre-molded stack with lenses 110 can include a stack with four or more lenses 110, or a stack with two lenses 110, or even a single lens 110, the number of lenses 110 depending on the specific application. Contrary to common sense, the inventors have found that a stack with multiple lenses 110 is easier to thermoform to a curved substrate 10 (or thermoform to a mold 40) than a stack with a single lens 110.

[0058] Throughout this disclosure, the term "transparent" is used broadly to encompass any material through which one can see. The term "transparent" does not exclude translucent, hazy, frosted, tinted or pigmented materials.

[0059] The coatings described throughout this disclosure may be applied by known methods such as spin coating, dip coating, or vacuum deposition.

[0060] The above description is given by way of example and not by way of limitation. Based on the above disclosure, those skilled in the art can design variations within the scope and spirit of the invention disclosed herein. In addition, multiple features of the embodiments disclosed herein can be used alone, or different features can be used in combination with each other, and are not intended to be limited to the specific combinations described herein. Therefore, the scope of the claims is not limited by the embodiments shown.

Claims

1. A method of making a pre-molded stack of lenses mountable on a curved substrate, the method comprising: placing a moldable stack of lenses on a mold, the moldable stack of lenses comprising two or more lenses and an adhesive layer between each pair of adjacent lenses of the two or more lenses; applying heat and pressure to the moldable stack of lenses to prepare a pre-mold stack of lenses from the moldable stack of lenses; as well as The pre-molded stack of lenses is removed from the mold.

2. The method according to claim 1, further comprising: obtaining three-dimensional shape data from the curved substrate; as well as The mold is formed using the three-dimensional shape data. The method of claim 2 , wherein said obtaining three-dimensional shape data comprises optically scanning said curved substrate.

4. The method of claim 1, wherein the curved substrate and the mold are the same type of windshield. The method of claim 1 , wherein the mold comprises a compound curved surface.

6. The method of claim 1, wherein the applying heat and pressure comprises arranging a plurality of heaters on a frame, the frame being positioned to direct the heaters toward the moldable stack of lenses.

7. The method of claim 1, wherein applying heat and pressure comprises pressing the moldable stack of lenses with one or more rollers.

8. The method of claim 1, wherein the moldable stack of lenses further comprises a sacrificial layer disposed on an outermost lens of the stack, the sacrificial layer comprising a sacrificial lens and a sacrificial adhesive between the sacrificial lens and the outermost lens of the stack.

9. The method of claim 8, wherein the sacrificial layer is more heat resistant than the outermost lens of the stack.

10. The method of claim 9, wherein the sacrificial layer is less scratch resistant than the outermost lens of the stack.

11. The method of claim 8, wherein the sacrificial layer is less scratch resistant than the outermost lens of the stack.

12. The method of claim 8, wherein the sacrificial lens comprises a biaxially oriented polyethylene terephthalate film.

13. The method of claim 12, wherein the biaxially oriented polyethylene terephthalate film is capable of withstanding temperatures between room temperature and 220°C for two hours.

14. The method of claim 8, wherein the sacrificial lens comprises an opaque polyester film.

15. The method of claim 14, wherein the outermost lens of the stack comprises a transparent polyethylene terephthalate film.

16. A pre-molded stack having two or more lenses mountable on a curved substrate, the pre-molded stack comprising: A stack of two or more lenses; as well as an adhesive layer between each pair of adjacent lenses of the two or more lenses; Wherein the pre-molded stack has a compound curvature.

17. The pre-molded cover of claim 16, wherein each of the two or more lenses comprises a biaxially oriented polyethylene terephthalate film.

18. A method of making a pre-molded stack having one or more lenses mountable on a curved substrate, the method comprising: placing a moldable stack having one or more lenses on the mold, the moldable stack comprising the one or more lenses and one or more adhesive layers respectively disposed thereon; applying heat and pressure to the moldable stack to prepare a pre-molded stack having one or more lenses from the moldable stack having one or more lenses; as well as The pre-molded stack having one or more lenses is removed from the mold.

19. The method according to claim 18, further comprising: obtaining three-dimensional shape data from the curved substrate; as well as The mold is formed using the three-dimensional shape data.

20. The method of claim 19, wherein said obtaining three-dimensional shape data comprises optically scanning said curved substrate.

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