Light guide glass material

Abstract

The vehicle glazing (10) has a light guide stack (22) disposed between a portion of an inner transparency (26) and a portion of an outer transparency (28). The light guide stack includes a polycarbonate film (32) bonded to the transparencies (26, 28) by PET layers (38, 40). One side of the PET layers (38, 40) is attached to the film by silicone (34, 36) and the other side is attached to the transparencies by PVB (42, 44). The film's extended tab terminates on an edge to which the light bar (14) is attached, and visible light propagates from the light bar through the edge and into the film. Visible light propagates through etched sections in the film's smooth surface to form an image. One transparent extension protects the polycarbonate tab and supports the light bar during installation of the glazing within the vehicle opening.

Description

Technical Field

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 894,037, filed Aug. 30, 2019, the entire disclosure of which is incorporated herein by reference.

[0002] The invention disclosed herein relates to a glazing suitable for use in vehicle windows and a method of making such glazing.

Background Art

[0003] The development of vehicles is also directed towards electric vehicles and autonomous vehicles. In addition, there is a desire for communication from the vehicle to people outside of it, such as pedestrians and other vehicle drivers. For these and other reasons, there has been an increasing interest in vehicle glazing that collaborates with various sensors to form communication with vehicle drivers and other people through designs and alphanumeric codes displayed on the glazing. Such combinations also assist “head-up” displays, which are often considered safer and more reliable than other information systems and methods.

[0004] In this regard, attention has been directed to systems incorporating LED front lighting technology. LEDs are convenient for optical guide designs intended for high performance because LEDs have a relatively high coupling efficiency. In such a system, a preferred material for directing light into the optical guide has a high refractive index and a high reflectivity. Inside the optical guide, when light travels through the optical guide in the direction of net internal reflection to the end of the optical guide, the light is reflected to travel back and forth across a plurality of surfaces. In particular, LED front lighting has been found to satisfy lower power requirements than conventional backlighting technology. In an LED front lighting system, the optical guide displays a fixed image in response to illumination from an illuminated light-emitting diode in the “on” state. Such an image cannot be seen when the LED is in the “off” state.

[0005] A "light guide" is an optically transparent material capable of propagating and distributing visible light. Light guide materials employ the principle of reflection resulting from the different refractive indices of two materials. Light guides are used to uniformly distribute a light source over a predetermined range. Examples of applications for such light guides include LCD backlighting, information displays, mood lighting, and design lighting effects.

[0006] In front lighting, all power is used to form a light image (as opposed to forming the silhouette of the illuminated panel). For example, FLEx Lighting supplies LED front lighting products that incorporate ultrathin flexible light guides in the form of film or sheet. The light guide film, thinner than a piece of paper, is illuminated through the edge of the film from a light stick (stick-shaped light source) or a light bar (bar-shaped light source). Typically, LEDs are too large to simply butt against the edge of the film. Instead, a light bar is mounted on the edge of the thin film, and the LED is focused on the end of the light bar to propagate visible light into the film.

[0007] Ultra-thin light guide films can conform to many contours, and as a result, can accommodate many glass material shapes. The ultra-thin light guide film emits visible light from its surface according to the etching on its surface. Thus, the film can convey a message according to a series of designs and alphanumeric characters etched onto the surface of the light guide film. Examples of such messages include conventional road signs and / or written instructions.

[0008] A typical thin film light guide has a thickness ranging from approximately 25 to 75 microns (μm). A light bar is used to propagate light in the visible wavelength range to the edge of the film. The light transmitted within the light guide film is generally confined between the smooth surfaces of the film, except in areas where the smooth surface is disturbed by etching or other surface discontinuities. This configuration has been found to require relatively low power while providing relatively high uniformity, good contrast, a good color range, and a wide viewing angle.

[0009] According to the invention disclosed herein, an ultrathin optical guide is a film of polycarbonate (PC) material that functions as an optical guide and optical transmission film. Vehicle glass materials typically employ polyvinyl butyral (PVB) as an intermediate layer. Although PC does not adhere to PVB, it adheres to vinyl acetate (EVA) and polyurethane (PU), so EVA or PU layers can be used on both sides of the PC film to adhere the optical guide to an adjacent transparent body in an optical guide stack.

[0010] In addition, polyethylene terephthalate (PET) can be bonded to PVB and urethane, and silicone can be used as a binder with PC. Therefore, the PC layer of the optical guide stack, i.e., the PC film, may include multiple transparent layers of PET facing both sides of the PC film. The PVB layer is added to one side of the PET layer and bonded to the adjacent transparent material. Since PET is not laminated to PC, the multiple PET layers are bonded to the PC layer by an adhesive such as silicone. However, it was found that further modifications are necessary to create an optical guide stack suitable for use in automotive glass materials. [Overview of the project]

[0011] According to the invention disclosed herein, a glass material that projects light in the form of an image comprises a glass material laminate including at least one transparent body and an optical guide laminate stack including a PC film. The surface of the PC film is etched according to a design or symbol in a form designed to convey a message. When visible light is propagated from the side edge of the PC film, the light is emitted from the etched portion of the surface according to the etched design or symbol.

[0012] In some cases, the light source is added to the glass material before it is delivered to the vehicle assembly site. In other cases, the light source is added when the glass material is installed in the vehicle opening (portal) for the glass material.

[0013] The glass laminate includes a film, the film containing a polyethylene terephthalate (PET) cladding layer on one or both sides of the PC film. The PET layer is preferably bonded to the PC with a binder such as silicone.

[0014] In automotive glass materials containing more than one transparent sheet, the multiple transparent sheets are typically separated by an intermediate layer, such as PVB or another suitable material. To match the thickness of the optical guide stack to the thickness of these portions of the glass material containing the intermediate layer, the optical guide stack often includes one or more spacer layers. In a preferred embodiment, the spacer layers may be made of EVA, PU, ​​PVB, or a combination thereof.

[0015] To support the lamination process, a partial vacuum is preferably applied to the optical guide laminated stack to remove trapped air between the multiple layers of the optical guide laminated stack. In some cases, the glass material includes a transparent sheet with a peripheral edge, which defines the outer perimeter of the transparent sheet and is combined with an optical guide laminated stack having a PC film terminated at a film edge. The film edge is positioned inside the perimeter of the transparent sheet, and the transparent sheet is connected to a light source connectable to the transparent sheet. In this way, the transparent material extends beyond the PC film, protecting the PC film from accidental bending, impact, or other shocks. This protection is particularly important while installing the optical guide glass material into the vehicle opening. At this point, the glass material assembly is heat-treated to bond the multiple layers of the glass material process. The heat-treatment process tends to make the polycarbonate tabs brittle and more susceptible to damage from impacts with the vehicle body. The glass material with the film edge positioned inside the perimeter of the transparent sheet is preferably degassed in a vacuum bag. In some cases of glass materials configured in this way, a light source can be added before the optical guide glass material is heat-treated, thereby eliminating the need to connect the light source to the glass material lamination during the vehicle assembly process once the assembly reaches the assembly site.

[0016] In other cases, the glass material includes a transparent sheet with a peripheral edge, which defines the outer perimeter of the transparent sheet, and is combined with an optical guide stack containing a PC film, the PC film terminating at a film edge located outside the transparent sheet. Thus, the polycarbonate film of the optical guide stack extends to form an optical guide tab. Before attaching the light source to the PC film, the glass material is preferably degassed using a vacuum collar that surrounds the transparent sheet and the optical guide stack adjacent to its perimeter. The glass material thus constructed can be manufactured relatively quickly because degassing with a vacuum collar is faster than degassing with a vacuum bag.

[0017] Preferably, the disclosed glass material includes a first transparent body, a second transparent body, and an optical guide stacked stack disposed between the portion of the first transparent body and the portion of the second transparent body. The optical guide stacked stack includes a polycarbonate film, the polycarbonate film including a plurality of main surfaces arranged opposite to each other. The plurality of portions of the oppositely arranged main surfaces constitute a smooth continuous surface, however, at least one portion of at least one main surface has a plurality of discontinuities in the smooth continuous surface of the main surface. Light of the visible light spectrum propagates through the polycarbonate film between the smooth continuous portions of the plurality of main surfaces of the polycarbonate film and proceeds out of the polycarbonate film from the discontinuities in the smooth continuous surface. An intermediate layer is disposed between the portion of the first transparent body and the portion of the second transparent body where the optical guide stacked stack is not present. The intermediate layer has a nominal thickness approximately the same as the nominal thickness of the optical guide stacked stack, thereby limiting the generation of bubbles and distortions during the manufacture of the glass material in the region of the glass material where the optical guide stacked stacked stacked stacked against the intermediate layer. A light bar is connected to the edge of a polycarbonate film, and visible spectrum light propagates from the light bar through the edge of the polycarbonate film into the polycarbonate film.

[0018] Other objects and advantages of the inventions disclosed herein will become apparent to those skilled in the art as we proceed to a detailed description of some preferred embodiments herein.

[0019] Preferred embodiments of the invention disclosed herein are shown and described below in connection with the accompanying drawings. [Brief explanation of the drawing]

[0020] [Figure 1] This is a perspective view of an optical guide glass material according to the invention disclosed herein. [Figure 2] Figure 1 is a perspective view of the optical guide glass material, showing further details of the optical guide, including extension optical guide tabs that can be used for connecting to light sources such as light bars. [Figure 3]Figure 2 shows a more detailed view of the glass material, specifically a magnified view of a portion of the optical guide glass material shown in Figure 2. [Figure 4] This is another enlarged view of a portion of the optical guide glass material shown in Figure 2, showing further details of the glass material and including the extended portion of the PC film. [Figure 5] This figure shows a modified embodiment of the disclosed optical guide glass material in which a protective glass layer extends from the main body of the glass material. [Figure 6] This figure shows another modified embodiment of the disclosed optical guide glass material, in which a protective glass layer extends from the main body of the glass material and the optical guide body is in contact with the edge of another glass layer. [Modes for carrying out the invention]

[0021] In the invention disclosed herein, a glass laminate comprising at least one transparent sheet is combined with an optical guide laminate stack useful for vehicle applications. In many vehicles, side lights comprise only a single transparent sheet, while front glass materials such as windshields comprise two or more transparent bodies separated by an intermediate layer. Although preferred embodiments of this specification are described in relation to windshields, the invention disclosed herein is also applicable to glass materials typically employing a single transparent sheet, according to the claims.

[0022] According to a preferred embodiment of the present specification shown in FIG. 1, the vehicle glass material 10 is used as a windshield, and an optical guide stack is attached so as to cross within the daylight opening (DLO) of the windshield. For reasons that will be described in detail later, the glass material 10 incorporates an optical guide stack 12, and the optical guide stack 12 includes a PC film. The glass material 10 includes a first transparent sheet 12a and a second transparent sheet 12b disposed on both sides of the optical guide stack 12. The first transparent sheet 12a has a peripheral side edge 12c that defines the periphery of the first transparent sheet 12a, and the second transparent sheet 12b has a peripheral side edge 12d that defines the periphery of the second transparent sheet 12b. Further, the optical guide stack 12 has tabs 13, and the PC film 12e of the optical guide stack 12 extends outside the periphery of the first transparent sheet 12a and extends outside the periphery of the second transparent sheet 12b. Throughout the optical guide stack 12, the PC film 12e has a surface 13a directed toward the first transparent sheet 12a and a surface 13b directed toward the second transparent sheet 12b. The surface 13a is disposed on the opposite side of the PC film 12e from its surface 13b, and a film edge 13c is disposed between the surface 13a and the surface 13b. The portions of the film surface 13a and the surface 13b each have a smooth continuous surface. Light in the visible light spectrum that illuminates the film edge 13c propagates through the PC film 12e between the smooth continuous portion of the film surface 13a and the smooth continuous portion of the film surface 13b.

[0023] When the glass material 10 is attached to a vehicle, it is preferable that a light source such as a light bar 14 illuminates the film edge 13c and propagates light through the PC film 12e. In some cases, a light source such as an optical guide 14 is adhered to a portion of the film edge 13c of the PC tab 13. In other cases, a light source such as an optical guide 14 is adhered to a portion of the film edge 13c, and the film edge 13c may be disposed in the periphery defined by the peripheral side edge 12c of the first transparent sheet 12a, or may be disposed in the periphery defined by the peripheral side edge 12 of the second transparent sheet 12b, or may be disposed in the periphery of both the first transparent sheet 12a and the second transparent sheet 12b.

[0024] When visible light is irradiated from, for example, the LED 16a to the end portion 16 of the light bar 14, the light from the LED propagates through the light bar 14 and the film edge 13c of the PC film 12e adjacent thereto. Inside the PC film 12e, the light propagates between the smooth surfaces 13a and 13b of the PC film 12e. The portions of the surfaces 13a and 13b of the PC film 12c preferably have an uneven pattern such that the surfaces are discontinuous. Such a pattern may be formed by etching or a similar process so as to form a pattern in the shape of alphanumeric characters, a design, or other images. The light moving through the PC film 12e between the surfaces 13a and 13b passes through the uneven portions formed by etching, that is, the discontinuous portions, and exits the PC film 12e, forming a visible pattern on the surface 13a or the surface 13b according to the discontinuous pattern. Thus, the surface 13a or the surface 13b may be engraved or etched with a series of designs or alphanumeric characters, thereby forming a readable message or an indicative image. In the example of FIG. 1, the design shows a visible message warning of a curve in the road.

[0025] Further details of the vehicle glass material according to the present invention disclosed herein are shown in FIG. 2. FIG. 2 shows a light guide stack 22 extending only to a part of the daylight opening (DLO) of the vehicle glass material 24. A plurality of glass material transparent bodies, an intermediate layer separating the plurality of glass material transparent bodies, and details of the light guide stack 22 are shown and described in relation to FIGS. 3 and 4.

[0026] FIG. 3 shows the light guide stack 22 and the remaining glass material laminate 24 thereof. In the glass material laminate 24, the inner transparent body 26 and the outer transparent body 28 are separated by the PVB intermediate layer 30. During the lamination process, the transparent layers 26, 28 are bonded to the PVB intermediate layer 30. As a result, even if the transparent body 26 or the transparent body 28 is broken, the transparent bodies 26, 28 are sufficiently bonded to the PVB intermediate layer 30, and the fragments of the transparent bodies 26, 28 remain attached to the PVB intermediate layer 30 as a whole.

[0027] To limit weight, reduce material costs, and for other reasons, the overall thickness of the glass material 24 is made as thin as possible. However, the practical effects of performance requirements for the glass material, such as resistance to wind load, impact resistance, chip resistance, shatter resistance, and other factors, have been found to impose a minimum thickness on vehicle glass materials. Although the minimum thickness of vehicle glass materials varies depending on the purpose and orientation of the glass material in the vehicle, commercial factors have comprehensively established the minimum thickness of conventional transparent layers and conventional laminated layers. In PVB used for windshields, the nominal thickness of conventional PVB layers is 0.76 mm. In some cases, thin PVB layers of 0.38 mm may be used for vehicle windshields.

[0028] For glass materials as shown in Figures 2 and 3, where the optical guide stack 22 interferes with the edge of the PVB interlayer 30, it was found that the overall thickness of the optical guide stack must be very close to the overall thickness of the PVB interlayer 30. To avoid visible strain, bubbles, and other undesirable effects that may occur during the lamination process, the overall thickness of the optical guide stack 22 must be very close to the overall thickness of the PVB interlayer 30. Therefore, in a motor vehicle glass material intended for use as a windshield with a nominal thickness of 0.76 mm of PVB interlayer, the thickness of the optical guide stack must also be approximately 0.76 mm to avoid visible strain in the glass material after lamination.

[0029] In the embodiment shown in Figure 3, the optical guide stack 22 includes a PC film 32 and PET clad layers 38 and 40 bonded to both sides of the PC film 32 by silicone layers 34 and 36, respectively. In other examples, a clad layer other than PET bonded by silicone may be used. The thicknesses of the PC film 32, clad layers 38 and 40, and silicone layers 34 and 36 are considerably thinner than the thickness of the PVB interlayer 30, which is 0.76 mm (30 mils). For example, the PC film thickness is approximately 0.127 mm (5 mils), the thickness of each PET clad layer is approximately 0.076 mm (3 mils), and the thickness of each silicone layer is approximately 0.041 mm (1.6 mils). Two intervening layers 42 and 44 are included to bring the thickness of the optical guide stack close to the thickness of the PVB interlayer 30. The intervening layers 42 and 44 allow the PET layers 38 and 40 to be bonded to their respective transparent bodies 26 and 28. In the example in Figure 3, the spacers 42 and 44 are made of PVB. Other compositions such as EVA and PU may be used for the spacers 42 and 44. In some cases, the optical guide stack consists of a layer of PC film 32 and a layer of EVA or PU bonded to the PC film 32 and transparent bodies 38 and 40, avoiding the need for PET, PVB, or other layers. PVB, PU, ​​and EVA with a thickness of approximately 0.38 mm (15 mil) are commercially available. By selecting spacers 42 and 44 with a nominal thickness of 0.38 mm (15 mil), the overall thickness of the optical guide stacked stack comes close enough to the overall thickness of the PVB interlayer 30, avoiding the different thicknesses causing visible strain, bubbles, and other undesirable effects during the lamination process.

[0030] According to the invention disclosed herein, the optical guide stack 22 constitutes an intermediate layer between the inner transparent body 26 and the outer transparent body 28. In the invention disclosed herein, the transparent bodies 26 and 28 are preferably glass. Since PET does not bond to glass, the PET layers of the optical guide stack 22 are covered with PVB layers 42 and 44, respectively. The total thickness of the optical guide stack 22 includes both the PVB layers 42 and 44 covering the PET layers 38 and 40. The optical guide stack 22 must be approximately equal to the nominal thickness of the PVB intermediate layer 30. In the example of Figure 3, the thicknesses of the PC film 32, silicone layers 34 and 36, PET layers 38 and 40, and PVB layers 42 and 44 must be approximately equal to the thickness of the PVB intermediate layer 30, which is 0.76 mm.

[0031] Although the overall thickness of the optical guide stack 22 matches the thickness of the PVB interlayer 30, repeated experiments to achieve the required overall thickness revealed that the selection of the respective thicknesses of the PC film 32, silicone layers 34, 36, PET layers 38, 40, and PVB layers 42, 44 is not simply a matter of selecting or modifying commercially available products. Other factors and limitations that give rise to variables not apparent to those skilled in the art must also be accommodated. In fact, the identification and selection of preferred thicknesses for each layer of the optical guide stack 22 is carried out in a way that is quite counterintuitive and contrary to previously known selections and methods.

[0032] For example, the PVB layers 42 and 44 must have a minimum thickness that supports sufficient lamination with their respective glass layers 26 and 28. This is necessary to ensure that multiple portions of the glass material 24 incorporating the optical guide stack 22 meet various performance requirements for the windshield, such as avoiding free glass fragments during shattering and other factors. It was also found that the PET layers 38 and 40 of the optical guide stack 22 must have a thickness of at least 0.0762 mm (3 mils). This is necessary to avoid undesirable results for the PET layers during lamination, namely flow, wrinkling, and uneven surfaces of the PET layers 42 and 44 during the autoclave process of the lamination process. The use of multiple PET layers, typically of about 0.0508 mm, was surprising and unpredictable. This is because, in the prior art, it was stipulated that multiple PET layers having such effects should be made thinner than 3 mils (about 0.076 mm) and not as thick as in the invention disclosed herein. As another example, it was found that the PC film thickness must be 2 mils (0.0508 mm) to avoid wrinkles in the PC film during the autoclave process of the lamination process. Preferably, the PC film thickness is about 5 mils (0.127 mm), and more preferably in the range of 3 to 4 mils.

[0033] Figure 4 shows that, according to the invention disclosed herein, it is preferable to remove the PET layers 38, 40 and the silicone layers 43, 36 from a portion of the PC film 32 that extends as a tab 13 beyond the periphery of the transparent bodies 26, 28. In addition, it has been found that it is preferable for the PC film 32 to be made thinner than a typical thin optical guide. Preferably, the thickness of the PC film 32 is in the range of 0.0508 mm (2 mils) to 0.127 mm (5 mils). The reason for removing the PET and silicone layers from the extended tab portion of the PC film 32 and limiting the thickness of the PC film 32 is due to an improved manufacturing method. These modifications and limitations of the PC film result in increased flexibility to adapt to commercial processes for forming automotive glass materials.

[0034] In the commercial manufacturing of automotive glass materials, the glass stack undergoes a vacuum process before the autoclave step of the lamination process. The purpose of the vacuum process is to remove air trapped between the various layers of glass material before the autoclave step of the lamination process. If excess air remains between these layers, the glass material tends to have visible defects such as air bubbles. Other undesirable results such as delamination may also occur.

[0035] To remove excess air, a vacuum ring is placed around the glass material 24 before the lamination process. The vacuum ring is in close contact with the edge of the glass material 24, and as a result, the vacuum state inside the vacuum ring is transferred into the interior of the glass material. In this way, air is drawn from between the layers of glass material into the vacuum ring until a sufficient vacuum level is reached inside the glass material stack.

[0036] For the vacuum ring to effectively transmit a vacuum state into the interior of the glass stack, the multiple ports of the vacuum ring must be close to the edges of the glass stack. This means that the allowable gap between the periphery of the glass stack and the inward-facing side surface of the vacuum ring must be small. As previously described in relation to Figure 1, the tab portion 13 of the PC film 12e extends beyond the periphery 12c, 12d of the transparent sheets 12a, 12b of the glass material, and as a result, the light bar 14 transmits light into the PC film 12e through the exposed edge 13a of the PC film 12e. However, because the tab 13 of the PC layer 12 extends beyond the periphery of the transparent sheets 12a, 12b, if the vacuum ring is positioned around the periphery of the glass stack, the vacuum ring will interfere with the tab 13.

[0037] Conventionally, it was believed that the PC film 12e had to have sufficient mechanical strength for acceptable contact with the vacuum ring. This led to designs in which the PET cladding layers 38, 40 of the PC film 32 were maintained throughout the tab 32 and the PC film 32 was made thicker in order to provide the PC film 32 with additional mechanical strength for acceptable contact with the vacuum ring. Surprisingly, however, the invention disclosed herein yielded the opposite result.

[0038] Firstly, according to the invention disclosed herein, the PET layers 38, 40 and the silicone layers 34, 36 are completely removed from the PC film 32. Secondly, the PC film 32 is thinner than any known thickness. In the invention disclosed herein, the PC film 32 resolves interference with the vacuum ring by its flexibility rather than its mechanical strength. In the invention disclosed herein, the PC film 32 is flexible enough to bend out of the path of the vacuum ring without damaging the PC film, while the vacuum ring still maintains a sufficient vacuum inside the glass material. This contradicts the requirement for additional mechanical strength that would be provided by a relatively thick PC film.

[0039] The embodiments shown and described in relation to Figures 2 to 4 may further incorporate a light source, such as a light guide fixed to the tab portion of the PC film 32. The light source may be added before the delivery of the glass material to the vehicle assembly site, or it may be added to the glass material as part of the larger process in vehicle assembly.

[0040] Figure 5 shows a modified embodiment of the invention disclosed herein. In the embodiment of Figure 5, the PC film 12e includes a PC film tab 13 that terminates at the edge 13a. The light bar 14 is connected to the edge 13a of the PC film 12e, as described in relation to Figure 1. Also, as described in relation to Figure 1, when the end 16 of the light bar 14 is illuminated, light propagates from the light bar 14 through the edge 13a into the PC film 12. However, in the embodiment of Figure 5, the glass sheet 28 extends beyond the edge 13a of the tab 13 and beyond at least a portion of the light bar 14. Thus, the light bar 14 is preferably fixed to the glass sheet 28 by a binder or other suitable fastening method, so that the glass sheet 28 mechanically supports the light guide 14 and provides greater stability for the light guide 14 and the PC film tab 13 which are outside the periphery of the periphery side surface of the transparent body 26.

[0041] The structure shown in Figure 5 provides greater durability during the manufacturing and handling of the glass material 10, and when the glass material 10 is installed in the vehicle. This structure has been found to protect the PC film 12 from damage or tearing during handling or during the installation process of the optical guide after autoclaving. The extended portion of the glass sheet 28 can also serve as a guide to maintain the stability of the tab 13 and optical guide 14 when positioning the glass material 10 during installation in the vehicle, and when installing the glass material.

[0042] In the embodiment shown in Figure 5, vacuum channels are generally unsuitable for degassing the glass laminate stack because the clearance tolerance of the vacuum channels does not accommodate the difference between the periphery of transparent body 26 and the periphery of transparent body 28. For example, a vacuum channel moving close to the edge of transparent body 26 would interfere with the extended portion of transparent body 28. Therefore, in the embodiment shown in Figure 5, a vacuum bag or equivalent device is preferable to be used to degass the glass material before heating or other curing processes in an autoclave.

[0043] The extended portion of the glass sheet 28 has been found to provide protection for PVB, polyurethane, or other intermediate layer materials, particularly after such materials have been made somewhat brittle by autoclaving or other heating or curing processes. For example, when installing glass material into a vehicle opening, the extended tab may be damaged by contact with the vehicle body.

[0044] Figure 6 shows that the light bar 14 is in contact with the peripheral edge 12c of the transparent body 26. When the light bar 14 is positioned to be in contact with the peripheral edge in this manner before autoclaving, the body of the light guide 14 forms a seal with the peripheral edge 6 of the transparent body 26 during the autoclaving step of the lamination process. This seal helps maintain the lamination of the light guide stack and avoids bubbles in the lamination, particularly near the peripheral boundary of the transparent body 26. To assist in the formation of such a seal, the invention disclosed herein employs a light guide having a body made of Delrin® or a similar plastic material.

[0045] The embodiment in Figure 6 also shows that it is preferable for the thickness of the optical guide (measured perpendicular to the surface of the inner transparent body 28) to be less than 3.0 mm. More specifically, the thickness (T) of the optical guide 14 is 2.6 mm or less. The thickness of the optical guide, as used in connection with the embodiments in Figures 1 to 4, is typically 5 mm. However, the low profile (thickness) of the optical guide preferred in the embodiment in Figure 6 allows the optical bar to abut against the periphery of the inner transparent body 26, and the maximum height of the assembled glass material (including the optical bar) is not higher than the outer surface of the outer transparent body 26. In this way, the assembled glass material can accommodate openings of standard dimensions and shapes that accept glass materials for many vehicles.

[0046] Other features, purposes, and advantages of the invention disclosed herein are described below, along with the claims.

Claims

1. A glazing that projects a predetermined pattern of light in response to an illumination signal, comprising: A glass material stack; a light guide laminate stack; The glass laminate comprises: a) at least one transparent sheet defining a peripheral side edge; b) a second transparent sheet having a surface facing the at least one transparent sheet; and c) an intermediate layer disposed between the second transparent sheet and the at least one transparent sheet, the intermediate layer having a first surface facing a surface of the at least one transparent sheet and a second surface facing a surface of the second transparent sheet directed toward the at least one transparent sheet, the separation length between the first surface and the second surface of the intermediate layer defining a thickness of the intermediate layer; the light guide laminate stack is disposed between the at least one transparent sheet and the second transparent sheet in a portion of the glass laminate and borders an edge of the interlayer, the light guide laminate stack having a first surface facing at least a portion of the at least one transparent sheet and including a film; the film has a first film surface, a second film surface disposed on the film opposite the first film surface, and a film edge between the first film surface and the second film surface, each of a portion of the first film surface and a portion of the second film surface comprising a smooth continuous surface whereby light in the visible spectrum propagates through the film between a portion of the smooth continuous surface of the first film surface and a portion of the smooth continuous surface of the second film surface, the first film surface comprising a textured pattern within its smooth continuous surface whereby light propagating through the film between the first film surface and the second film surface passes out of the first film surface from the textured pattern of the first film surface; further comprising a light source coupled to a film edge of a film of the light guide laminate stack, whereby light in the visible spectrum propagates from the light source through the film edge and into the film between the first film surface and the second film surface; The light source has a body contacting a periphery of the second transparent sheet.

2. The glass material of claim 1 , wherein the light source comprises a light emitting diode.

3. The glass material of claim 1 , wherein the films of the light guide laminate stack comprise polycarbonate.

4. 4. The glass material of claim 3, wherein the light guide laminate stack further comprises at least one polyethylene terephthalate layer between the film and the at least one transparent sheet.

5. 4. The glass material of claim 3, wherein the light guide laminate stack further comprises at least one spacing layer between the film and the at least one transparent sheet, the spacing layer material being selected from the group consisting of polyvinyl butyral, ethylene vinyl acetate, polyurethane, and combinations thereof.

6. 5. The glass material of claim 4, wherein the light guide laminate stack further comprises at least one spacing layer between the polyethylene terephthalate layer and the at least one transparent sheet, the spacing layer material being selected from the group consisting of ethylene vinyl acetate, polyvinyl butyral, polyurethane, and combinations thereof.

7. The glazing of claim 1 , wherein the film edge is disposed outside a perimeter defined by a peripheral side edge of the at least one transparent sheet.

8. The glass material of claim 1 , wherein the light guide laminate stack has a thickness that corresponds to a thickness of the interlayer.

9. The glass material of claim 1 , wherein the films of the light guide laminate stack comprise polycarbonate.

10. 10. The glass material of claim 9, wherein the light guide laminate stack further comprises at least one polyethylene terephthalate layer between the film and the second transparent sheet.

11. 11. The glass material of claim 10, wherein the light guide laminate stack further comprises a spacing layer between the polyethylene terephthalate layer and the second transparent sheet, the spacing layer material being selected from the group consisting of polyvinyl butyral, polyurethane, ethylene vinyl acetate, and combinations thereof.

12. 10. The glass material of claim 9, wherein the light guide laminate stack further comprises a spacing layer between the film and the second transparent sheet, the spacing layer material being selected from the group consisting of ethylene vinyl acetate, polyurethane, and combinations thereof.

13. 12. The glass material of claim 11, wherein a film edge of the film extends beyond a perimeter of the second transparent sheet to form an extension tab outside a perimeter of the second transparent sheet and comprising a distal end of the extension tab.

14. 14. The glass material of claim 13, wherein the film has a thickness in the range of 2 mils to 5 mils.

15. The glazing of claim 1 , wherein the body of the light source forms a seal with a peripheral edge of the second transparent sheet.