DESCRIPTION

FIELD OF THE DISCLOSURE

The present disclosure relates to the field of automotive glazing and, particularly, to automotive with lighting means providing an aesthetically pleasing and efficient lighting solution.

BACKGROUND

The transportation industry is rapidly adapting to provide more sustainable means of transportation, such as low-emission and electric vehicles, which requires modifications to integrated systems such as air-conditioning, cabin heating, navigation systems, and lighting to comply with the government regulations. Autonomous vehicles designed to provide a comfortable travel experience, often feature large panoramic glazing roofs and windows. However, the preference for large glazing roofs and windshields has led to the need for embedding technology such as lighting, displays, and other controls into the glazing.

One of the most aesthetically appealing lighting solutions is to attach a lighting source to the edge of the glazing and have the light guided inside the glazing through total internal reflection (TIR) and scattered at specific features on the surface, illuminating the passenger cabin. The glazing itself acts as a waveguide for the light, conducting it similarly to an optical fiber. While glass fibers have been used for conducting light for many years in communication systems, the same principle can be applied with laminated glazing.

Light injection into the glazing is achieved by optically coupling the light into the glass from at least one edge of the glazing, a method commonly used in non-automotive applications.

The injected light is then trapped within the glass sheet by the principle of TIR. Edge injection of light into the vehicle glazing can provide ambient cabin illumination, with the glass functioning as a waveguide for the light dispersing means on the glass surface refract the light and provide illumination while being substantially invisible when the lighting means is off. The light dispersing may be patterned to form a graphic.

In the most commonly made illuminated laminate glazing, the inner glass layer is illuminated by a lighting means along at least a portion of the glazing’s periphery. The light dispersing means is deposited on a glass layer major surface interior to the laminate, thereby protecting it from wear and damage. Coatings can be applied to the outer glass layers to further improve performance by reflecting incidental light from the dispersing means inboard. An opaque layer, such as a black frit, may also be used to block light from exiting to the exterior of the vehicle. A dark composition of outer glass layer and/or a dark tint plastic interlayer may be used to minimize the amount of light visible from outside of the vehicle. Conversely, the light dispersing means, plastic interlayer, and outer glass layer can be designed to maximize visibility from the exterior to use the light for signaling.

One major drawback of edge injection is the poor illumination intensity, resulting in a need for larger power and more lighting bulbs.

Several documents such as US8944655, US9630551 , EP2349782B1 , CN102245431 B propose different or complementary solutions for coupling light sources into the edge of the glazing however most of them are entitle to the same drawback poor illumination. There is a significant amount of light that is lost when injecting light from the edges of the glazing. The main problem is that most of the light sources economically available are not collimated, and, therefore, emit in all directions, leading to significant amount of lost light when injecting light from the glazing’s edge. It is hard to treat the glazing edge surface to have light emitted into a specific angle, due to mechanical integrity and manufacturability challenges. Car manufacturers often use point light sources that emit in all directions, and only a portion of the light that emits in a range of angles actually enters and propagates throughout the length of the glazing. This limitation necessitates more light sources or a higher intensity light source that requires more power generating more heat. Some of the light strips and brackets used in the automotive industry, if not properly ventilated, can reach temperatures higher than 100°C, leading to premature failure of the light bulbs.

Another drawback of the edge attachment is the limited space available in this region that cannot fit a light source appropriately illuminating the glazing. Additionally, the edge of the glazing is susceptible to ingress of fluids such as water and external contaminants, and conventional sealing means like encapsulation of the glazing edge normally can cause problems on the light source. Encapsulation is usually carried out at extremely high temperatures which can damage the light source.

The present disclosure proposes a solution to all the problems listed above and describe a vehicle glazing with enhanced light illumination.

BRIEF SUMMARY

It is an object of the disclosure to provide a laminated glazing having enhanced luminosity. This object can be attained by: providing a laminated glazing having a wet zone, the glazing comprising: at least two glass layers comprising: an outer glass layer having an exterior surface oriented towards the outside of the laminated glazing, an interior surface oriented towards the inside of the laminated glazing, and an edge surface; an inner glass layer having an exterior surface oriented towards the inside of the laminated glazing, an interior surface oriented towards the outside of the laminated glazing, and an edge surface; a plastic bonding layer disposed between said at least two glass layers; a step region formed by the edge surface of the outer glass layer extending beyond a portion of the edge surface of the inner glass layer; a light source disposed in the step region, directed towards the interior surface of the outer glass layer; a light guide disposed in the step region between the light source and the edge of the inner glass layer, which guides the light emitted by the light source into the laminated glazing; a light reflector disposed in the step region between the light source and the edge of the inner glass layer, reflecting the light emitted by the light source to the light guide; an electrical circuit in the step region, selected from the group of printed circuit boards (PCBs), FR4, or flexible printed circuits (FPCs), connected to the light source; a housing disposed in the wet zone of the glazing; wherein said housing protects the step region from fluids and external agents; wherein said housing houses the light source, the light guide, and the light reflector, and wherein said housing heat is configured to dissipate the heat from the light source and electrical circuit; and an encapsulation means disposed in the edge of the outer glass layer, configured to collaboratively work with the housing to further protect the step region against fluids and external agents, and maintaining a fixed connection with the housing.

Some advantages:

• Higher illumination efficiency.

• Fits into the wet zone.

• Provides a heat dissipation solution.

• Enhanced light color mixing.

• Provides protection of the light assembly and glazing against fluids and external contaminants.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1A illustrates the cross section of a typical laminated automotive glazing.

Figure 1 B shows the cross section of a typical laminated automotive glazing with performance film and coating.

Figure 2A shows the cross section of a laminated glazing as one embodiment of this disclosure.

Figure 2B shows the cross section of a laminated glazing as another embodiment of this disclosure.

Figure 3 shows the cross section of a laminated glazing as another embodiment of this disclosure.

Figure 4 shows a laminated roof with the light module of this disclosure deconstructed in many layers. Reference Numerals of Drawings

2 Glass;

4 Bonding/Adhesive layer/Plastic Interlayer;

6 Obscuration/Black Paint;

12 Infrared reflecting film;

18 Infrared reflecting coating;

20 Housing;

22 Light source;

24 Light reflector;

26 Adhesive;

28 Light guide;

30 Electrical circuit;

32 Encapsulation;

40 Wet zone;

50 Wet zone adhesive;

60 Light dispersing layer;

101 Exterior side of glass layer 201 , number one surface;

102 Interior side of glass layer 201, number two surface;

103 Exterior side of glass layer 202, number three surface;

104 Interior side of glass layer 202, number four surface;

201 Outer glass layer;

202 Inner glass layer.

DETAILED DESCRIPTION

The present disclosure can be understood by reference to the detailed descriptions, drawings, examples, and claims. However, it should be noted that the disclosure is not limited to specific compositions, articles, devices, and methods unless otherwise specified. The terminology used herein serves to describe aspects of the disclosure and is not intended to be limiting.

The following terminology is used to describe the glazing of the disclosure.

A glazing is an article composed of at least two laminated glass layers, which allows for light transmission and/or viewing of the side opposite the viewer. It can be mounted in an opening of a building, vehicle, wall, roof, or other framing member or enclosure. A preferred embodiment is a glazing for a vehicle. The glazing of the disclosure may comprise multiple glass layers. To comply with regulatory requirements, the glazing must be laminated, and one or more of the multiple glass layers may be annealed, heat strengthened, or chemically strengthened.

Laminates, are generally articles comprised of multiple thin sheets of material with relatively uniform thickness, each having two opposite major surfaces, permanently bonded to one another across at least one major surface of each sheet.

Annealed glass is glass that has been slowly cooled from the bending temperature through the glass transition range, relieving any stress left from the bending process.

Two processes can be used to increase the strength of glass: thermal strengthening, which involves rapid cooling (quenching) of hot glass, and chemical tempering, which achieves similar effect through ion exchange chemical treatment.

Various types of glass that may be used include, but are not limited to, common sodalime glass, aluminosilicate, lithium aluminosilicate, borosilicate, glass ceramics, and other inorganic solid amorphous compositions that undergo a glass transition and are classified as glass, including those that are not transparent. The glass layers may comprise heat absorbing glass compositions and infrared reflecting coatings.

A wide range of coatings, is available to enhance the performance and properties of glass. These include, but are not limited to, anti-reflective, hydrophobic, hydrophilic, self- healing, self-cleaning, anti-bacterial, anti-scratch, anti-graffiti, anti-fingerprint, and antiglare coatings. Any of these coatings may be combined with and applied to the glazing of the disclosure.

Application methods include Magnetron Sputtered Vacuum Deposition (MSVD), and other techniques known in the art, such as pyrolytic, spray, Controlled Vapor Deposition (CVD), dip, sol-gel, and others. In the embodiments, the coating of the disclosure is applied using the MSVD process.

Making reference to the figures, the plastic bonding layer 4 (interlayer) is disposed between the two glass layers, permanently bonding them together, having the primary function of bonding the major surfaces of adjacent glass layers to each other. The bonding layer may be made from various materials known in the art, including but not limited to polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), or thermoplastic polyurethane (TPU).

The light source may comprise several closely grouped LED dies to provide high lumen output. The emitted light may be a single color or RGB color. An electrical circuit is located in the step region and is connected to the light source. The electrical circuit can be selected from the group that includes printed circuit boards (PCBs), FR4, or flexible printed circuits (FPCs). The electrical circuit may be comprised of either a single continuous element or multiple elements connected in a string. The electrical circuit may conform to the shape of the glazing, whether curved or flat.

The light guide is formed into a shape that is configured to guide the light emitted by the light source into the glazing. In a preferred embodiment, the light guide redirects the light emitted by the light source into the edge of the inner glass layer at an angle between 30° and 60° with respect to the light source emitting surface. In a most preferred embodiment, the light guide redirects the light emitted by the light source at an angle of 45° with respect to the light source emitting surface. The light guide may be comprised of a single continuous light guide or multiple light guides. The light guide is made from a transparent material such as polycarbonate (PC), poly methyl methacrylate (PMMA), or liquid silicone rubber (LSR). The light guide may be formed of a single continuous element or multiple segments, and can conform to the shape of the glazing, whether curved or flat.

At least part of the edge surface of the outer glass layer extends beyond the edge surface of the inner glass layer, forming an offset, also known as step region.

The step region is formed by the edge surface of the outer glass layer extending beyond a portion of the edge surface of the inner glass layer. Such step region is located in the wet zone of the glazing, where the glazing is affixed to the vehicle body. The step region houses a light source, which may emit single or RGB color light, and can include a single or a plurality of light dies. The light source is disposed in the step region, directed towards the interior surface of the outer glass layer. This region is called the wet zone because it is susceptible to the ingress of fluids and external agents such as dust, pollution, water, detergent, and other agents from outside. The wet zone is typically a small area, around 20 mm in width and less than 10 mm in depth. It is very challenging to find commercial light stripes or brackets that contain light sources facing the edge of the glazing. Therefore, light sources are more easily accommodated facing one of the major surfaces of the glazing, and a light guide is used to direct light into the edge of the glazing.

A light reflector is disposed in the step region between the light source and the edge of the inner glass layer, reflecting the light emitted by the light source to the light guide. The light reflector may be a single continuous element or a plurality of reflectors. The light reflector may be fixed to a housing or may be fixed to the interior surface of the outer glass layer. The light reflector can be comprised of a reflecting coating or a transparent material coated with a metallic reflecting coating. The light reflector serves to redirect light from a top-emitting LED into the edge of the glass, and ensures proper color mixing. This element can be made of polycarbonate with a metallic coating from 0.05 to 0.1 microns, which can be white or mirror-finished. Alternatively, the reflector can be made of any material comprising a reflecting coating, or a metallic material such as aluminum, steel or similar. The light reflector improves light injection efficiency by redirecting more light to the glazing, and enhances color mixing for more homogeneous illumination. The light reflector may be comprised of a single continuous element.

The encapsulation is disposed in the edge of the outer glass layer and works collaboratively with the housing. The housing is fixed to the encapsulation, and together they provide protection against humidity and external agents, as required by the IP67 weatherproof protection standard.

The housing serves to house or allocate the light source, light reflector, and the light guide as well as to protect the step region against fluids and external agents. The light source and the electrical circuit are physically attached to the housing. The housing is disposed in the wet zone, and is configured to dissipate the heat from the exterior, light source and/or the electrical circuit due to its material. The housing material can be selected from the group of aluminum, copper, steel, or any other metal or material with good heat transfer properties. This prevents overheating and improves the lifetime durability of the light assembly. The housing is fixed to the encapsulation on one side and adhered to the inner glass layer, protecting the elements inside the step region.

In one embodiment, the housing may be fixed to the region close to the edge of the inner glass layer, as illustrated in Figures 2A and 2B. In another embodiment, the housing may extend over the interior surface of the inner glass layer to allow extra space for the electrical circuit, as shown in Figure 3. This embodiment, is advantageous in situations where there is not enough horizontal space in the step region to accommodate the electrical circuit and additional electronics.

Typical automotive laminated glazing cross sections are illustrated in Figures 1A and 1 B. A laminate is comprised of two layers of glass, the exterior or outer, 201 and interior or inner, 202, permanently bonded together by a plastic bonding layer 4 (also named as interlayer). In a laminate, the glass surface on the exterior of the vehicle is referred to as surface one 101 or the number one surface. The opposite face of the exterior glass layer 201 is surface two 102 or the number two surface. The glass 2 surface that is on the interior of the vehicle is referred to as surface four 104 or the number four surface. The opposite face of the interior layer of glass 202 is surface three 103 or the number three surface. Surfaces two 102 and three 103 are bonded together by the plastic bonding layer 4. An obscuration 6 may also be applied to the glass. Obscurations are commonly comprised of black enamel frit printed on either the number two 102 or number four surface 104 or on both. The area of the glazing not covered by an obscuration is the daylight opening. The laminate may have a coating 18 on one or more of the surfaces. The laminate may also comprise a film 12 laminated between at least two plastic bonding layers 4.

One embodiment of this disclosure is a vehicle laminated roof, as illustrated in Figure 4. The laminate is comprised of an outer glass layer 201 and an inner glass layer 202 bonded by a PVB plastic bonding layer 4. The exterior glass layer extends on two sides beyond the inner glass layer, forming a step region. A light module is disposed in the step region, formed by a light source 22, light guide 28, reflector 24 and a housing 30 to protect them all. An encapsulation means 32 (not shown in the Figure) is disposed in the edge of the glazing to provide additional protection against fluids and external agents.

In another embodiment, the luminous laminated glazing may further comprise a light dispersing layer disposed between the inner glass layer and the plastic bonding layer. The light dispersing layer can be comprised of a transparent ink layer applied to the exterior surface of the inner glass layer. This layer serves to evenly distribute the light emitted by the light source throughout the laminated glazing, providing a uniform lighting effect.

A transparent ink layer 60 with light dispersing particles is applied to the exterior surface of the inner glass layer. An obscuration layer 6 is applied onto the interior surface of the outer glass layer and onto the interior surface of the inner glass layer.

Several arrangements of the light module such as the light source, electrical circuit, light guide, reflector, housing, and encapsulation, are provided in the following examples and in Figures 2A, 2B and 3. These arrangements allow for various configurations of the glazing system to accommodate different vehicle designs and requirements.

In some embodiments, the luminous laminated glazing may be curved, conforming to various design requirements and aesthetic preferences. Curved glazings can be used in a variety of applications, such as automotive windshields, vehicle roofs, windows, building facades, or other curved surfaces requiring light transmission and additional functionality provided by the integrated light source, light guide, and light reflector, or where efficient lighting and protection against fluids and external agents are required.

The disclosure further extends to a vehicle comprising the luminous laminated glazing described above. The vehicle can be any type of vehicle, such as an automobile, bus, train, or boat, where the luminous laminated glazing can provide a functional and visually appealing lighting solution.

In some embodiments, the luminous laminated glazing may have an electrical circuit that is comprised of a single continuous circuit. This configuration may simplify the overall design, manufacturing process, and reduce the number of connections required, thereby improving the reliability of the electrical connections and the operation of the light source. In alternative embodiments, the electrical circuit can be comprised of a plurality of electrical circuits. This configuration allows for greater flexibility in design, including the potential for separate control of individual sections or groups of light sources or other electrical components. It may also provide redundancy in case of failure of one or more electrical circuits, improving the reliability and functionality of the luminous laminated glazing.

In curved luminous laminated glazings or glazings with irregular shapes, the electrical circuit may be designed to conform to the shape of the glazing. This can be achieved by using flexible printed circuits (FPCs) or other suitable materials and manufacturing techniques that allow for the formation of electrical circuits that can follow the contours of the glazing.

Similarly, the light guide in some embodiments may conform to the shape of the glazing. This can be accomplished by using materials with suitable flexibility and optical properties, such as certain types of polycarbonate (PC), poly methyl methacrylate (PMMA), or liquid silicone rubber (LSR), among others. The light guide may be designed and manufactured to follow the contours of the curved or irregularly shaped glazing, ensuring that the light emitted by the light source is effectively guided into the laminated glazing and uniformly distributed across its surface.

In some embodiments, the light reflector may also conform to the shape of the glazing. This can be achieved by using flexible materials with suitable reflective properties or by applying a reflective coating to a substrate that conforms to the shape of the glazing. The conforming light reflector ensures that the light emitted by the light source is efficiently reflected towards the light guide, regardless of the shape of the glazing, contributing to the uniform distribution of light across the surface of the laminated glazing. The above-described embodiments provide a wide range of options for the design and implementation of luminous laminated glazings with various shapes, sizes, and configurations. The various components, such as the light source, light guide, light reflector, and electrical circuit, can be adapted to suit specific application requirements, ensuring optimal performance and functionality.

EXAMPLES

1. Example one comprises a laminated automotive windshield with a 2.1 mm thick ultra-clear soda-lime inner and outer glass layer with a 0.76 mm thick PVB interlayer and a light scattering layer applied to surface three, 103. Outer glass layer is larger than inner glass layer forming a step region on the edge. A light source 22 made of a set of RGB LED dies is connected to a flexible PCB strip 30 attached to an aluminum housing 20 in the step region. The RGB LED dies face surface two, 102, of the glazing. A light guide 28 made of LSR or PMMA is placed in between the RGB LED source and the edge of the glazing. A light reflector 24 is attached to the housing and redirects the light coming from different directions into the light guide as illustrated in Figure 2A. The housing 20 is fixed to surface four, 104 of the glazing by means of an adhesive 26. On one side, the housing 20 is attached to the encapsulation 32 that serves as a protecting means against fluids and external agents that might be present in the wet zone 40.

2. Example two is similar to example one. The main difference is that the light concentrator and the light guide are both fixed to surface two, 102, of the glazing in the step region as illustrated in Figure 2B.

3. Example three is based on a laminated automotive sunroof, consisting of a 2.5 mm thick tinted soda-lime inner and outer glass layer with a 1.14 mm thick PVB interlayer and a light scattering layer applied to surface three, 103. The outer glass layer is larger than the inner glass layer, forming a step region on the edge. A light source 22, composed of an array of RGB LED dies, is connected to a flexible PCB strip 30 embedded within a copper housing 20 in the step region. The RGB LED dies face surface two, 102, of the glazing. A light guide 28, made of PMMA, is positioned between the LED source and the edge of the glazing. A light reflector 24 is attached to the interior surface of the outer glass layer and redirects the light coming from various directions into the light guide. The housing 20 is fixed to surface four, 104, of the glazing by means of a mechanical clip 34. On one side, the housing 20 is attached to the encapsulation 32, which provides protection against fluids and external agents that may be present in the wet zone 40.

4. Example four is a variation of example three. The main differences are that the laminated automotive sunroof employs a curved glazing design and that the electrical circuit, light guide, and light reflector all conform to the curved shape. The light guide 28, made of flexible LSR, follows the curvature of the glazing, ensuring efficient light distribution across the curved surface. Similarly, the light reflector 24 is made of a flexible material coated with a metallic reflective coating, allowing it to conform to the curved glazing shape. The flexible PCB strip 30 is designed to follow the contours of the curved glazing, providing a seamless integration of the electrical circuit with the curved design. The housing 20, made of aluminum, is attached to surface four, 104, of the glazing by means of adhesive 26 and mechanical clips 34. The encapsulation 32 is also designed to conform to the curved shape, ensuring effective protection against fluids and external agents in the wet zone 40.

The dimensions in the figures were exaggerated to demonstrate the details of each element and should be taken in no way as limiting to the disclosure.

It should be understood that various modifications and variations can be made to the embodiments described herein without departing from the scope of the invention, which is defined by the claims. Furthermore, specific features from one embodiment can be combined with features from other embodiments to create new embodiments within the scope of the present invention.