WO2025104744A1

WO2025104744A1 - A composite pane with light guiding means

Info

Publication number: WO2025104744A1
Application number: PCT/IN2024/052230
Authority: WO
Inventors: Robin C JAYARAM; Gayathri PRABHU; Arjun C.R.M
Original assignee: Saint Gobain Sekurit France
Current assignee: Saint Gobain Sekurit France
Priority date: 2023-11-14
Filing date: 2024-11-14
Publication date: 2025-05-22
Anticipated expiration: 2026-05-14

Abstract

Provided herein is a composite pane (110) for automotive glazing, a system (200) and a method (300) thereof The composite pane has one or more display element (114) between said first substrate (111) and second substrate (112), configured to display one or more conditions. It has one or more light guiding means (120) comprising an inner material of a first refractive index and an outer material of a second refractive index wherein said first refractive index is greater than the second refractive index, and said light guiding means (120), disposed via the peripheral region of the composite pane, are configured to provide guided light towards said display elements (112). The solution increases the volume percentage of light entering the substrate and reduces the loss of light at the edges of the composite pane.figure for publication:

Description

TITLE

A COMPOSITE PANE WITH LIGHT GUIDING MEANS

TECHNICAL FIELD

The present disclosure relates to display solutions in glazing, particularly, this disclosure relates to a display solution in automotive glazing and more particularly it relates to inclusion of a light guiding means as means for light injection for a display or lighting solution in automotive glazing

BACKGROUND

Background description includes information that may be useful in understanding the present disclosure. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed disclosure, or that any publication specifically or implicitly referenced is prior art.

Display and lighting system in automotives finds numerous applications. It is useful for Advanced Driver Assistance Systems (ADAS) based solutions, aesthetics and safety as well. Such automotive lighting or display may be exterior or interior. The display in vehicles may have diffusive material or other illuminating material capable of functioning as display or lighting sources. For applications involving display in glazing, there may be provided a light diffusing element on the glazing and a means of light injection. Known in the art are light injection solutions that involve illumination of the substrate through the unground edges of the glazing. However, in applications involving automotive glazing, the edges are completely rounded. This is disadvantageous for conventional light injection due to scattering of light at edges. It has been observed that usual static display application comprises a light diffusing substrate and a means of illumination. General sources of illuminations involve illumination through the edges, making use of polymer-based materials that behave as its own source. These materials are capable of transferring light from one place to another, however, this becomes complex to realize for automotive glazing applications, primarily due to the complete grinding of glass edges, lamination feasibility issues and fixtures for LED mounting.

In an implementation, when the glasses are edge lit, 60-75% of the light is lost due to scattering at the edges. Of the remaining volume of light, some of it is lost in internal rarefaction losses. This along with the material property of the substrate, together constitutes to a substantial loss in overall illumination of the display unit. Thus, resulting in a dim illumination. Lamination of these materials have also been challenging primarily due to their lack of stability at elevated temperatures, or compatibility with the interlayer or both.

Reference is made to CN113251342A that discloses lighting assembly for a vehicle roof and vehicle roof for a motor vehicle. It is suitable for providing a comfortable and efficient illumination of a vehicle interior of a motor vehicle. It relates to a roof for a motor vehicle having such a lighting assembly.

Another reference is made to CN101666462A that discloses about edge-lighting backlight module and light guide element and linear light source thereof. Provided therein is a flat light guide plate that can reflect the light of the linear light source to form an area source with uniform emergent light. The edge-lighting backlight module may reduce the number of parts and strengthen heat dissipation. It may even avoid the conditions of non-uniform brightness.

A still further reference is made to WO2021/198262A1 that discloses a vehicle window having a light source and a light-conducting layer. The window has a wedge-shaped or trapezoidal cross section. Provided further is a light source, which is preferably an light emitting diode (LED) strip is an insert of the casting resin.

It has been observed that the edge of the glazing is completely ground. Any form of edge light injection would be infeasible due to convex nature of the glazing edge that scatters light before it enters the glazing. With varying geometry of the boundary of the glazing, light source cannot be maintained at a constant distance from the display element comprising light diffusing material. This results in non-uniform diffusion, gradient lighting, loss of light, unwanted haze effects due to the non-linear light emission nature of light source.

Further, it has been observed that the curvature of the glazing such as a windshield limits the possibility to inject light tangent to the display element through edge lighting. Solutions such as LED beading would form localised heating zones (depending on the wattage of the LED) when pasted on the edge. Additional dynamic elements or colour variants are difficult to be added with such solutions.

In view of the solutions known hitherto and the drawbacks of the same, it has been observed that there is a requirement of a light injection means in display or lighting system in automotive glazing that provides improved volume percentage of light entering the substrate, improved lighting output and dynamic display ranges

SUMMARY OF THE DISCLOSURE

An object of the present invention is to provide a solution to overcome the drawbacks of the prior art.

Another object of the present invention is to provide a solution to increase the volume percentage of light entering a substrate in glazing and reduce the loss of light. Yet another object of the present invention is to provide a dynamic display range in display design possibilities.

Still another object of the present invention is to provide a display or lighting solution in automotive glazing with uniform light output is achieved.

A further object of the present invention is to provide a display or lighting solution in automotive glazing with directional light input to substrate.

In an aspect of the present invention is provided a composite pane for automotive glazing. Said pane comprising a first substrate of glass or polymer having a first face and a second face, a second substrate of glass or polymer having a third face and a fourth face, and one or more interlayers sandwiched between said first substrate and second substrate forming a single unit. It comprises one or more display element between said first substrate and second substrate, configured to display one or more conditions. It further includes one or more light guiding means comprising an inner material of a first refractive index and an outer material of a second refractive index wherein said first refractive index is greater than the second refractive index, and said light guiding means, disposed via the peripheral region of the composite pane, are configured to provide guided light towards said display elements. The light guiding means are one or more fibre-optic cables, having a core and a cladding, disposed either individually or in groups for directing light towards the display element. One of the layers of the composite pane is configured to function as the cladding. The composite pane comprises a reflective interface between a light source and the light guiding means adapted to concentrate light towards the light guiding means. The light source is adapted to be positioned at a periphery of the composite pane by means of encapsulation. The composite pane comprising a diffusive layer between the light guiding means and the display elements, wherein said diffusive layer is selected such that the refractive index of the diffusive layer matches with the display element. Said diffusive layer is selectively of a varying composition to provide a uniform illumination across a transition region between the light guiding means and the display element . The light guiding means is modified to create a local change in its refractive index (localised change in total internal reflection) for extracting light. The light guiding means comprises one or more cut-outs adapted for extracting light from the edges of the cut-outs, wherein said one or more cut-outs selectively includes a diffusive material. The light guiding means is deformed to create the local change in its refractive index (localised change in total internal reflection) for extracting light. The light guiding means is selected such that the refractive index of said light guiding means matches the refractive index of the display element. The composite pane includes one or more reflective layer along with said display elements, having different refractive indices for enabling selective colouring or mixing of light for display. The display element includes one of or a combination of electroluminescent material, phosphor material, photoluminescent material, ultra-violet emissive material, a diffusive material, holographic display or fibre-optic.

In another aspect of the present invention is provided an automotive display system comprising a composite pane as detailed above. It further includes a driver unit operably coupled with said composite pane for enabling functioning of the one or more display elements. Said driver unit is operably coupled with an electronic control unit for obtaining inputs for display. The electronic control unit is configured with a humanmachine interface and/or one or more data obtaining devices for obtaining inputs for display. The driver unit is configured to active the one or more display elements sequentially or simultaneously.

In another aspect of the present invention is provided a method of making the composite pane. The method comprises the steps of: pre-processing, the first substate and the second substrate, bending S, the first substrate and the second substrate; preparing, a transmission and a receiving end of the light guiding means by providing an optically matching interface for transition regions, wherein refractive index is matched by cleaving the light guiding means according to the thickness of display layer; preparing, the display element, a diffusive layer, and/or an emissive layer according to a pre-determined concentration and design, wherein a thickness of the display element is fixed in accordance with the dimensions of the light guiding means; placing one or more display elements on a desired face of one of the substrates of the composite pane, wherein said display element is any of printing or patch or a combination thereof; selecting the number of light guiding means and placing it at the edge of the display element either individually or in groups; affixing an interface between the light guiding means and the display element; placing the interlayer and the first substrate on top the assembled light guiding means and the display element and placing the second substrate at the bottom of the assembled light guiding means to form the composite pane assembly; de-airing the composite pane assembly; and autoclaving S the de-aired composite pane assembly. The method further talks of making one or more cut-outs in the interlayer to place the light guiding means such that during lamination said light guiding means fuses with the interlayer without any significant change in thickness of the interlayer.

The embodiments of the present invention provide increased volume percentage of light entering the substrate and Reduced loss of light at the edges of the composite pane, it includes dynamic display range and uniform light output is achieved as well. It facilitates directional light input to substrate. The various aspects of the present invention contribute towards, lighting being transferred from edges to display location within glazing. With the disclosed solution light sources need not be required for being mounted. It may be used in multi-coloured display achieved by coloured LED and may be used in combination with projection, reflective film and diffusive layers to create a background and pattern illumination. In the disclosure, animation may be enabled by means of sequential activation of Optical fibres/waveguides. The present solution makes use of utilization of a gradient diffusive composition to achieve uniform light intensity.

These and other objects of the invention are achieved by the following aspects of the invention. The following disclosure presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This presents some concept of the invention in a simplified form to a more detailed description of the invention presented later. It is a comprehensive summary of the disclosure, and it is not an extensive overview of the present invention. The intend of this summary is to provide a fundamental understanding of some of the aspects of the present invention.

The significant features of the present invention and the advantages of the same will be apparent to a person skilled in the art from the detailed description that follows in conjunction with the annexed drawings.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The following briefly describes the accompanying drawings, illustrating the technical solution of the embodiments of the present invention or the prior art, for assisting the understanding of a person skilled in the art to comprehend the invention. It would be apparent that the accompanying drawings in the following description merely show some embodiments of the present invention, and persons skilled in the art can derive other drawings from the accompanying drawings without deviating from the scope of the disclosure.

FIG. 1 illustrates a composite pane with display element according to an embodiment of the present invention. FIGs. 2A-2B illustrates the transition regions of a composite pane according to an embodiment of the present invention.

FIGs. 3A-3B illustrates means of disposing light guiding means in a composite pane according to an embodiment of the present invention.

FIGs. 4A-4B illustrates different means of display in a composite pane according to an embodiment of the present invention.

FIG. 5 illustrates a display system having a composite pane with display element according to an embodiment of the present invention.

FIG. 6 A illustrates a display system with light injection according to prior art.

FIG. 6B illustrates a display system with light injection according to an embodiment of the present invention.

FIG. 7 illustrates a method of making composite pane with display element according to an embodiment of the present invention.

Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the disclosure.

DETAILED DESCRIPTION

The present disclosure is now discussed in more detail referring to the drawings that accompany the present application. It would be appreciated by a skilled person that this description to assist the understanding of the invention but these are to be regarded as merely exemplary.

The terms and words used in the following description are not limited to the bibliographical meanings and the same are used to enable a clear and consistent understanding of the invention. Accordingly, the terms/phrases are to be read in the context of the disclosure and not in isolation. Additionally, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

A waveguide is a structure that guides waves by restricting the transmission of energy to one direction. The wave guide indicated herein primarily refers to optical waveguide. An instance of such a waveguide may be and not limited to fibre optic cable.

It is known to one skilled in the art that glazing refers to any and all the glass or similar material within a structure or the installation of any piece of glass or the similar material within a sash or frame. The glass windows of an automobile are referred to as glazing. For laminated glazing (also referred to herein as composite pane), two or more layers of glass or a similar material, are fused together with an interlayer in the middle. The fusion is completed with pressure and heat and it prevents the sheets of glass or the similar material from breaking. While some pieces of glass or the similar material might end up breaking into larger pieces, those pieces will stay together with the help of the interlayer, making it shatterproof.

The present invention, in its various embodiments, discloses a composite pane with display. Provided in said pane is one or more light guiding means for extracting light towards the display element. In the disclosed solution, the light is injected directly into the composite pane using light guiding means preferably optical waveguides such as fibre optic cables. These advantageously maximizes light injection. The composite pane as disclosed in the present invention having the waveguides facilitates for carrying light to one or more desired locations in the composite pane for illumination. It is known to one skilled in the art that the term composite pane or composite glass refers to a laminate having at least two glass substates which are connected by means of an adhesive intermediate layer.

Reference is made to FIG. 1 a composite pane (110) for automotive glazing. Said pane comprises a first substrate (111) of glass or polymer having a first face (fl) and a second face (f2) and a second substrate (113) of glass or polymer having a third face (f3) and a fourth face (f4). It further includes one or more interlayers (112) sandwiched between said first substrate (111) and second substrate (113) forming a single unit. An instance of the interlayer is Polyvinyl butyral (or PVB). Said composite pane (110) comprises one or more display element (114) between said first substrate (111) and second substrate (112). Said one or more display element (114) is configured to display one or more conditions. Such one or more conditions may include data or signal received as input for display. The display element may be used for either functional lighting or aesthetic lighting. The composite pane further comprises one or more light guiding means (120). Said one or more light guiding means (120) comprises an inner material of a first refractive index and an outer material of a second refractive index wherein said first refractive index is greater than the second refractive index. Said light guiding means (120) is disposed via the peripheral region of the composite pane and is configured to provide guided light towards said display elements (114).

In an embodiment of the present invention, the light guiding means (120) can may be waveguides. Said light guiding means (120) may be grouped or controlled individually to generate animations and dynamic colour gradients in the substrate. The light guiding means (120) may be one or more fibre-optic cables, having a core and a cladding, disposed either individually or in groups for directing light towards the display element (114). In an implementation, one of the layers either of the first substrate (111) or second substrate (112) or interlayer (113) of the composite pane is configured to function as the cladding.

In an embodiment of the present invention, the optical waveguides a refractive index more than substrates of the composite pane. This can advantageously eliminate the need of cladding in care of fibre optics cables being chosen as waveguides and it can further reduce the waveguide thickness. In an implementation of the present invention, the optical waveguides have a refractive index of more than 1.5 preferably 1.55 and above while substrates like glass have 1.5 and interlayer like PVB has a refractive index of around 1.42.

The one or more embodiments of the present invention facilitate for local light spot wastage or removal by way of refractive index matching. This scenario may occur in two specific cases (reference made to FIGs.2A and 2B) primarily at a transition (140) from the light source to optical waveguide and at a transition (150) from optical waveguide to display region. The refractive indices in these scenarios are matched to avoid wastage of light.

In an embodiment of the present invention, the composite pane (110) comprises a reflective interface (141) between a light source (130) and the light guiding means (120) adapted to concentrate light towards the light guiding means (120) as has been depicted in FIG. 2A. In an embodiment of the present invention, the light source may be Light Emitting Diode (LED). Light may propagate from said LED to the light guiding means (120) such as an optical waveguide via an intermediate transition. This intermediate transition may be achieved by means of the reflective interfacing attachment (141). In an implementation, said reflective interface (141) may be a coating or coating or a reflective transition layer configured to enable regular LEDs to be easily integrated to the tip or end of the fibre optic cluster. In another implementation said reflective interface may be conical polymer-based interface with inner silver-based coating. The customization may be done as per the size of the optical display area.

In the present invention, through total internal reflection, the directionality of light is advantageously improved and streamlined towards the display element (114) as compared to the spherical distribution in the LEDs without the in. This can reduce scattering of light inside the laminated glazing and reduce haze effects. This also allows the light source (LEDs) to be place outside of the glazing for applications such as that of edge lighting. Conventionally, in Edge lighting applications LED light source is placed right at the periphery of the glazing as depicted in FIG. 6A. In the present invention, it may advantageously be placed away from the peripheral region as well as seen in FIG. 6B.

Reference is made to FIG. 2B that discloses a display area transition in which a light guiding means (120) having one or more optical waveguide such as fibre optics waveguide configured to provide light towards display area having display elements (114). The transition from the light guiding means towards the display region is achieved by customizing the fibre and the display layer to have matching refractive index. The transitional intermediate region (150) may include a diffusive layer (160). In an implementation, said diffusive layer (160) is selectively of a varying composition to provide a uniform illumination across a transition region (150) between the light guiding means (120) and the display element (114).

In an embodiment of the present invention, the light guiding means (120) is modified to selectively change the total internal reflection for extracting light. The light guiding means (120) comprises one or more cut-outs adapted for extracting light from the edges of the cut-outs, wherein said one or more cut-outs selectively includes a diffusive material. Alternatively, the light guiding means (120) is deformed to selectively change the total internal reflection for extracting light. A waveguide such as a fibre optic works on the phenomenon of total internal reflection. In other words, whatever light enters via the waveguide, stays inside it until there is a change in the refractive index of the transmitting medium. In an embodiment of the present invention, the disclosed invention advantageously makes use of this phenomenon to introduce cut-outs in the waveguides to introduce a local change in the refractive index, thereby extracting light from the edges of the cut-outs. These cut-outs are either be used as is or may be filled with a light diffusing element and use the edges of the cut-out as source of illumination of the ink for display. In such an embodiment, the fibre-optic waveguide is extended as the display element. This waveguide may then be laminated within the glazing or the composite pane at any of the interfacing faces as per the use case. Reference is made to FIG. 4A that discloses a display in accordance with this embodiment of the present invention, fibre optic waveguide (120) is configured to have light extracting cut-outs (170) to function as display element. This advantageously mitigates the requirements of interfaces at transitional regions between optic waveguide and display.

In an alternative embodiment, indentations are provided on the optic fibre waveguides. This serves as an alternate means for extracting light out of the waveguides (120) by creating deformations along the path of light. Such deformations result in localized change in total internal reflection giving a virtual local change in refractive index, as the angle of reflection at that local region changes. Reference is made to FIG. 4B that shows fibre optic waveguide in form of a wire and flat based. Such indentations may be introduced in both flat and wire-based waveguides.

In an embodiment of the present invention is provided a composite pane (110) comprising one or more reflective layer along with said display elements (114), having different refractive indices for enabling selective colouring or mixing of light for display. Said display element (114) includes one of or a combination of electroluminescent material, phosphor material, ultra-violet emissive material, a diffusive material, holographic display or fibre-optic. In an embodiment of the present invention is provided a composite pane having display for 3-dimensional and multicolour creation using primary colours. This may be used with diffusive layer (160) or on its own as well. Additionally, in order to improve the contrast for display, the composite pane (110) may include a reflective layer or a different layer having a refractive index layer to enable selective colouring or mixing. The colour display may be achieved by means of emissive particle dispersion material which may be activated or illuminated by means of an activation such as an ultra-violet or infrared (UV or IR respectively) illumination or similar non-visible or monochromatic light source. Reference is made to FIG. 3B, where the light source (130) may include light of different colours to illuminate each of displays (DI, D2, D3) differently. In an implementation, the light source (130) may illuminate the substrates of the composite pane (110). In an implementation, the composite pane (110) may include more than two substates of glass or polymer (111, 113) such as for a bullet proof glazing. Such a composite pane may be further configured to provide a multi-layer lighting impact to create a depth or 3D effect or holographic effect.

In an implementation of the present invention, the ultraviolet (UV) emissive material may be chosen from phosphors including a host material and an activator material. The host material may be chosen from oxides, nitrides and oxynitrides, sulfides, selenides, halides or silicates of elements like zinc, cadmium, manganese, aluminium, silicon, or various rare-earth metals. The activator may be chosen from any of silver, copper and the like. One instance of UV emissive material may be Copper activated Zinc Sulphide- ZnS:Cu. In an implementation, the diffusive material may be chosen from enamel particles dispersed in polymer matrix. The polymer may be chosen from nitrocellulose polymer or poly methyl methacrylate (PMMA) or Polydimethylsiloxane (PDMS). It would be appreciated by one skilled in the art that these combinations of materials are by means of examples and not limitations. In an implementation of the present invention is provided a solution for display system or lighting solution that provides designing specific LED mounting for each variation of glass curvature. These challenges are addressed in the disclosed solution, where the light is injected directly into the lamination using optical waveguides such as fibre optic cables. These waveguides address the issues of maximum light injection and lamination compatibilities. These waveguides also allow carrying light to desired locations in the lamination for illumination. Additionally, waveguides can be grouped or controlled individually to generate animations and dynamic colour gradients in the substrate. A uniform distribution of these effects can be obtained by using a gradient diffusive substrate composition. Through total internal reflection, the directionality of light increases when compared to the spherical distribution in the LEDs. This can advantageously reduce scattering of light inside the laminated glazing and reduce haze effects. This also allows the source (such as and not limited LED’s) to be place outside of the glazing.

Reference is made to FIG. 5 that discloses an automotive display system (200). Said system (200) comprises a composite pane (110) as described in various embodiments of the present invention. They system further includes a driver unit (201) operably coupled with said composite pane (110) for enabling functioning of the one or more display elements (114). The driver unit (201) is configured to activate the one or more display elements sequentially or simultaneously. The driver unit (201) is responsible for the nature of the output in the display unit. The driver unit (201) is operably coupled with an electronic control unit, ECU, (203) for obtaining inputs for display. Both the driver unit (201) and the electronic control unit (203) are operably coupled to a compatible power supply, which may be a vehicle battery. In an implementation, the electronic control unit (203) may be the vehicle control unit. The electronic control unit (203) may be operably coupled to one or more means for input (204, 205, 206). The electronic control unit (203) may be configured with a human-machine interface (HMI) and/or one or more data obtaining devices for obtaining inputs for display. In an implementation of the present invention, the display system (200) involves a waveguide based light injection unit, and an integrated display element in the glazing. Such an integrated display element may be any coating which is diffusive or emissive or reflective or a combination. The driver unit of the display is controlled by vehicle ECU and is powered by the battery. The ECU receives the information data / inputs by means such as an HMI or manual input unit or input from a Global Positioning System (GPS) unit, from a sensor (such as and not limited to proximity, camera, temperature, parking assistance sensors and the like). The data so obtained is processed and converted to control instructions to the driver unit.

In an embodiment of the present invention is provided a method (300) of making the composite pane described in the various embodiments herein. The method has been depicted in FIG. 7. Said method (300) comprises pre-processing (S301), the first substate and the second substrate. This is usually followed by bending (S302), the first substrate and the second substrate. Further included in the method is the step of preparing (S203), a transmission and a receiving end of the light guiding means by providing an optically matching interface for transition regions. Here, care is taken for the refractive index to be matched by cleaving the light guiding means according to the thickness of display layer. In some embodiments, the transmission and receiving ends of the light guiding means are prepared to have an optically matching interface by cleaving perpendicular or at a low angle to match to the thickness of display layer.

Further, the pattern or design required for the display region is defined. The method thus includes preparing (S304), the display element, a diffusive layer, and/or an emissive layer according to a pre-determined concentration and design, wherein a thickness of the display element is fixed in accordance with the dimensions of the light guiding means. The pre-determined concentration is defined or fixed as per the application. Care is taken to have the thickness of display layer to be fixed for providing a matching optical light guiding means or waveguide end. The method further includes placing (S305) one or more display elements on a desired face of one of the substrates of the composite pane, wherein said display element is any of printing or patch or a combination thereof. The display element may be provided as coating, patch layer and the like (however not limited to these) onto the surface of glass as per the required location. Still further included in the method is the step of selecting (S306) the number of light guiding means and placing it at the edge of the display element either individually or in groups. The method (300) includes the steps of affixing (S307) an interface between the light guiding means and the display element and placing (S308) the interlayer and the first substrate on top the assembled light guiding means and the display element and placing the second substrate at the bottom of the assembled light guiding means to form the composite pane assembly. The interface may be affixed with an adhesive of similar refractive index as the waveguide or display element. In some implementation, the element itself may be used or it can be placed during the coating step of display layer. The method further includes de-airing (S309) the composite pane assembly and autoclaving (S310) the de-aired composite pane assembly. The steps of de-airing and autoclaving process to complete the lamination process and obtain the final optical waveguide and display integrated composite pane or laminated glazing. The light source may be connected to the light receiving end of the light guiding means using a connecting tool or by means of an encapsulation with a guideway provided to place the waveguide and light source.

In an implementation, the lighting layer having the light source may be encapsulated to the edge of the composite pane assembly. This may provide the light source as an integral part of the composite pane assembly and minimizes the loss of light. This may be achieved by means of a customized lighting module slots on the edges to accommodate the LEDs or a provision to sandwich the lighting strip by means of a reflective interior. In an embodiment of the present invention is provided a step of ensuring that delamination is avoided. Generally, when the substrates of the composite pane is laminated, there are chances of occurrence of delamination. The disclosed method thus includes making one or cut-outs in the form of slots or slits in the interlayer such as PVB. In ensures that during the lamination process, the interlayer advantageously fuses over the light guiding means such as a fibre optic cable. This will help with the thickness as well.

Example Embodiment: Provided is an automotive display system. Said display system may include a GPS unit that could provide the geographical navigation information to reach any selected location and the electronic control unit (ECU) may provide control instructions in the form for LEFT or RIGHT indicator signals. The driver unit of the display system may receive this information and convert this data to sequential or blinking instructions to the lighting unit such as an LED layer. The LED layer is used to illuminate this display region by means of the light injection unit such as and not limited to light waveguide, optical fibers and the like. The light injection may be provided as a LED based layer which may generate the different wavelengths needed to illuminate the display region. The display region may be a simple diffusive layer at the end of the injection layer or an emissive layer or in some cases a combination of diffusive and emissive layers.

In another example of the present invention, the LED may be activated through the sequential powering from the driver unit based on ECU input to create a continuous moving image and with different colours and patterns of different width to create a depth effect. The gradient in the individual layers may be achieved by varying the concentration of active particles across the width of the design thereby modifying the amount of illumination achieved. The waveguides disclosed in the composite pane are not limited by the source of light. It may be used in conjunction with edge lighting also along with various combinations. In some implementation, the glass edge lighting may illuminate the projection phosphors using UV light. Alternatively, the optical waveguide will provide diffusive background which may be used to improve contrast for the UV illuminated designs. In another combination both lighting may be white light and the combination may be used to improve the intensity of the display or design based on external lighting levels.

In yet another exemplary implementation of the present invention, the optical waveguides may exhibit a refractive index more than 1.5. In a preferred implementation, refractive index of waveguide may be 1.55 and above with refractive index of glass being 1.5 and PVB being 1.42. This can eliminate the need of cladding, thereby reducing the waveguide thickness. This arrangement works for all LED or point light source-based applications without the LED spotting effect. The UV emissive material is generally preferred to be phosphors that include a host material and an activator material. The host material includes oxides, nitrides and oxynitrides, sulfides, selenides, halides or silicates of elements like zinc, cadmium, manganese, aluminium, silicon, or various rare-earth metals. The activator material may include any of silver, copper and the like. In a preferred implementation, it is Copper activated Zinc Sulphide - ZnS:Cu. The diffusive material is enamel particles dispersed in polymer matrix and the polymer is nitrocellulose polymer or poly methyl methacrylate (PMMA) or Polydimethylsiloxane (PDMS).

Industrial Application: The disclosed invention is capable of providing guided light towards any kind of display element having diffusive or emissive or holographic material. It may be used in any form of glazing for quasi-static display applications. Such application may include and not limited to automotive glazing and building glazing such as facade. In one or more applications of the disclosed invention, the display element may be illuminated by means of diffusive element using an ultraviolet source. Using a combination of projection and diffusive element a coloured pattern of display may be created. Light guiding means may be selectively disposed and required coloured light source may be chosen. The disclosed invention may be used for animation of display elements. Animation of text or pictures can be provided by utilizing sequential activation of the optical fibres. According to an implementation of the present invention, the lighting units may be extended to cover the interior of glass to provide a multiple intensity lighting. The implementation of said lighting is cases dependent. For instance, LED / EL in the glazing having laminated glass can provide indication of safety critical or emergency information and use the light injection to provide a mild or subtle illumination for Logo or mood lighting. Such an application may be especially prevalent in a sunroof. In another implementation, the patterns created on the display may be designed to provide a 3D holographic impact for certain type of designs for an object detection feature utilizing data from the proximity sensor input.

In one of the modification cases, the usage of optically transparent adhesive may be used for integration to glass surface. This enables proper alignment and positioning with the glass surface. For encapsulated glazing, the transparent glazing needs to be placed on the Injection moulding die to enable embedding during the moulding process. Alternatively, slots may be provided on the encapsulation to act as guideways or holder for the waveguide elements.

In a further disclosure herein is provided a comparative study of the disclosed invention as compared with other conventional solutions and prior art:

Some advantages of the present invention are enlisted in the following:

• The various embodiments of the present invention are directed towards lighting means being transferred from edges to display location within glazing without loss of light.

• The disclosed solution does not require edge mounting of lighting source such as LEDs.

• The multi-coloured display may be achieved by coloured LED.

• The disclosed display system may be used in combination with a projection, reflective film and diffusive layers to create a background and pattern illumination.

• The disclosed solution may facilitate for animation enabled by means of sequential activation of optical fibres or waveguides.

• In the disclosed solution, the utilization of a gradient diffusive composition to achieve uniform light intensity.

Note that not all of the activities described above in the general description or the examples are required, that a portion of a specific activity may not be required, and that one or more further activities may be performed in addition to those described. Still further, the order in which activities are listed is not necessarily the order in which they are performed.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.

The specification and illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The specification and illustrations are not intended to serve as an exhaustive and comprehensive description of all of the elements and features of apparatus and systems that use the structures or methods described herein. Certain features, that are for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in a sub combination. Wherever, method steps are indicated, it is meant as a means for conveying the steps involved and it may or may not be sequential in nature. Further, reference to values stated in ranges includes each and every value within that range. Many other embodiments may be apparent to skilled artisans only after reading this specification. Other embodiments may be used and derived from the disclosure, such that a structural substitution, logical substitution, or another change may be made without departing from the scope of the disclosure. Accordingly, the disclosure is to be regarded as illustrative rather than restrictive.

The description in combination with the figures is provided to assist in understanding the teachings disclosed herein, is provided to assist in describing the teachings, and should not be interpreted as a limitation on the scope or applicability of the teachings. However, other teachings can certainly be used in this application.

As used herein, the terms “comprise(s)”, “comprising”, “include(s)”, “including”, “has”, “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive-or and not to an exclusive- or. For example, a condition A or B is satisfied by any one of the following: A is true (or present), and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

Also, the use of “a” or “an” is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural, or vice versa, unless it is clear that it is meant otherwise. For example, when a single item is described herein, more than one item may be used in place of a single item. Similarly, where more than one item is described herein, a single item may be substituted for that more than one item.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent that certain details regarding specific materials and processing acts are not described, such details may include conventional approaches, which may be found in reference books and other sources within the manufacturing arts. While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

List of reference numerals appearing in the accompanying drawings and the corresponding features: 110: composite pane 111: first substrate

113: a second substrate

112: interlayers

114: display elements fl, f2, f3, f4: faces of the composite pane

120: light guiding means

130: light source

140, 150: transitional region

141: reflective interface

160: diffusive layer

200: system

201: driver unit

202: power supply

203 : electronic control unit

204, 205, 206: input units and HMI

300: method

S301-S310: method steps

Claims

1. A composite pane (110) for automotive glazing comprising: a first substrate (111) of glass or polymer having a first face (fl) and a second face (f2); a second substrate (113) of glass or polymer having a third face (f3) and a fourth face (f4); one or more interlayers (112) sandwiched between said first substrate (111) and second substrate (113) forming a single unit; one or more display element (114) between said first substrate (111) and second substrate (112), configured to display one or more conditions; and one or more light guiding means (120) comprising an inner material of a first refractive index and an outer material of a second refractive index wherein said first refractive index is greater than the second refractive index, and said light guiding means (120), disposed via the peripheral region of the composite pane, are configured to provide guided light towards said display elements (112).

2. The composite pane (110) as claimed in claim 1, wherein said light guiding means (120) are one or more fibre-optic cables, having a core and a cladding, disposed either individually or in groups for directing light towards the display element (114).

3. The composite pane (110) as claimed in claim 2, wherein one of the layers (111, 112, 113) of the composite pane is configured to function as the cladding.

4. The composite pane (110) as claimed in claim 1, comprising a reflective interface (141) between a light source (130) and the light guiding means (120) adapted to concentrate light towards the light guiding means (120).

5. The composite pane (110) as claimed in claim 4, wherein the light source (130) is adapted to be positioned at a periphery of the composite pane (110) by means of encapsulation.

6. The composite pane (110) as claimed in claim 1, comprising a diffusive layer (160) between the light guiding means (120) and the display elements (114), wherein said diffusive layer is selected such that the refractive index of the diffusive layer (160) matches with the display element (114).

7. The composite pane (110) as claimed in claim 6, wherein said diffusive layer (160) is selectively of a varying composition to provide a uniform illumination across a transition region (150) between the light guiding means (120) and the display element (114).

8. The composite pane (110) as claimed in claim 1, wherein the light guiding means (120) is modified to selectively change total internal reflection for extracting light.

9. The composite pane (110) as claimed in claim 8, wherein the light guiding means (120) comprises one or more cut-outs adapted for extracting light from the edges of the cut-outs, wherein said one or more cut-outs selectively includes a diffusive material.

10. The composite pane (110) as claimed in claim 8, wherein the light guiding means (120) is deformed to selectively change total internal reflection for extracting light.

11. The composite pane (110) as claimed in claim 1, wherein the light guiding means (120) is selected such that the refractive index of said light guiding means (120) matches the refractive index of the display element (114).

12. The composite pane (110) as claimed in claim 1, comprising one or more reflective layer along with said display elements (114), having different refractive indices for enabling selective colouring or mixing of light for display.

13. The composite pane (110) as claimed in claim 1, wherein the display element (114) includes one of or a combination of electroluminescent material, phosphor material, photoluminescent material, ultra-violet emissive material, a diffusive material, holographic display or fibre-optic.

14. An automotive display system (200) comprising: a composite pane (110) as claimed in any one of the preceding claims 1-13; a driver unit (201) operably coupled with said composite pane (110) for enabling functioning of the one or more display elements (114); wherein said driver unit (120) is operably coupled with an electronic control unit (202) for obtaining inputs for display.

15. The automotive system (200) as claimed in claim 14, wherein the electronic control unit (202) is configured with a human-machine interface and/or one or more data obtaining devices (204, 205, 206) for obtaining inputs for display.

16. The automotive system (200) as claimed in claim 14, wherein the driver unit is configured to active the one or more display elements sequentially or simultaneously.

17. A method (300) of making the composite pane as claimed in any of the claims 1 to 13, wherein said method comprises: pre-processing (S301), the first substate and the second substrate; bending (S302), the first substrate and the second substrate; preparing (S303), a transmission and a receiving end of the light guiding means by providing an optically matching interface for transition regions, wherein refractive index is matched by cleaving the light guiding means according to the thickness of display layer; preparing (S304), the display element, a diffusive layer, and/or an emissive layer according to a pre-determined concentration and design, wherein a thickness of the display element is fixed in accordance with the dimensions of the light guiding means; placing (S305) one or more display elements on a desired face of one of the substrates of the composite pane, wherein said display element is any of printing or patch or a combination thereof; selecting (S306) the number of light guiding means and placing it at the edge of the display element either individually or in groups; affixing (S307) an interface between the light guiding means and the display element; placing (S308) the interlayer and the first substrate on top the assembled light guiding means and the display element and placing the second substrate at the bottom of the assembled light guiding means to form the composite pane assembly; de-airing (S309) the composite pane assembly; and autoclaving (S310) the de-aired composite pane assembly.

18. The method (300) of making the composite pane as claimed in claim 17, further comprising making one or more cut-outs in the interlayer to place the light guiding means such that during lamination said light guiding means fuses with the interlayer without any significant change in thickness of the interlayer.