FR2994125A1 - GLAZING FOR PRODUCING A LIGHT BEAM ACCORDING TO DIRECTION GIVEN BY INTEGRATED LEDS. - Google Patents

Abstract

The invention relates to a laminated glass pane (15) comprising at least two sheets (17; 19) of glass separated by at least one interlayer (21) for lamination, the pane further comprising at least one of the interleaves (21). ) laminating, at least one light emitting diode (23) capable of emitting light rays (35), characterized in that the diode or diodes are arranged facing at least one reflecting device (25) configured to concentrate and reflect the spokes (35) in a given direction.

Description

The invention is in the field of vehicle glazing, for example of motor vehicles, and concerns in particular light windows and vehicles having such glazings. BACKGROUND OF THE INVENTION . The invention is also directed to the methods of manufacturing such glazings. It is known to place bright windows for example on panoramic roofs or on the rear windows of vehicles. These glazings are conventionally composed of at least two superimposed glass sheets between which is placed at least one lamination interlayer, plastic material. The lamination interlayer is for example a sheet of polymeric material comprising polyvinyl butyral (PVB), an ethylene / vinyl acetate copolymer (EVA) or a thermoplastic polyurethane (TPU). The glass sheets are sheets of mineral glass and / or organic glass.

The organic glass may be composed of polycarbonate, polymethylmethacrylate, polyamide, or any other material known to those skilled in the art for such an application. The different glass sheets used may have identical or different compositions. For example, one of the sheets may consist of one mineral glass and the other of an organic glass. A black serigraphy is affixed on its periphery delimiting a glass clear. FIG. 1 shows an example of luminous glazing according to the prior art, known for example from document EP1886804 that can be used in particular for application to a vehicle ceiling lamp. The laminated glazing 1 is made bright by incorporating at least one set of LEDs 3 between a glass plate 5 and a plate 7 of a heat-conducting material, for example a metal plate. The LEDs 3 are arranged in a spacer sheet 9 and fed by a supply circuit 11. When the supply circuit is carried by the heat-conducting plate, an insulating strip 13 is inserted between the conductive plate 7 of heat and the insert 9.

It is possible to put the LEDs on the glass plate and associate them with reflective elements to reflect the luminous flux. The document WO2009 / 087583 describes a laminated glazing unit in which LEDs are integrated. The LEDs are arranged between the two sheets of glass, at the level of the interlayer of lamination. They are placed opposite operable reflectors allowing the passage of a state "reflection of light" to a state "light emission". One of the disadvantages encountered is that the light emitting method via diodes arranged behind a glass plate will diffuse in all directions and generate a light that illuminates the entire cabin. This diffusion of light generates glare discomfort for the driver or other passengers, and presents a risk of reflection on the dashboard, in the driving dials and / or in the rearview mirror. Finally, the diffusion of light in all directions impairs its intensity. It would therefore be interesting to be able to emit light in the manner of a conventional reading light, that is to say, to focus it and direct it towards a specific location of the passenger compartment. The object of the invention is to meet at least one of the drawbacks encountered in the prior art, and in particular the invention proposes a new luminous glazing capable of producing illumination with a luminous flux directed towards a specific location. For this purpose, the subject of the invention is a laminated glass pane comprising at least two glass sheets separated by at least one lamination interlayer, the pane further comprising, at the level of the lamination interlayer (s), at least one diode Electroluminescent device capable of emitting light rays, remarkable in that the diode or diodes are arranged facing at least one reflecting device configured to concentrate and reflect the rays in a given direction. According to particular embodiments, the assembly may include one or more of the following characteristics, taken separately or in any technically possible combination: the glazing is a luminous glazing. the reflecting device comprises at least one micro-reflector, preferably it comprises a plurality of micro-reflectors. the light emitting diode (s) and the reflecting device (s) are arranged in a recess of the interlayer (s). the glazing further comprises an antisolar, reflective or absorbent layer disposed between the lamination interlayer comprising the reflector device (s) and a glass sheet, preferably the glass sheet is the outer sheet. the glazing comprises at least two superimposed lamination interleaves, the light emitting diode (s) are arranged at a first lamination interlayer and the reflective device (s) are arranged at a second lamination interlayer. the first lamination interlayer comprising the diodes is an electroconductive layer of polyethylene terephthalate (PET), and the first interlayer is interposed between the second lamination interlayer and a third lamination interlayer PVB, TPU or EVA. one of the glass sheets carries, on the face of the glass sheet in contact with a lamination interlayer, a supply circuit of the light emitting diodes (LEDs). the reflective device or devices comprise at least one elliptical paraboloid-shaped device or in the form of a truncated pyramid open towards the light-emitting diodes. at least one micro-reflector device is in the form of an elliptical paraboloid and is sized and positioned for a light-emitting diode (LED) to be disposed at the focus of said paraboloidal shape. the light emitting diode (LEDs) are oriented to emit their light rays towards the reflective device or devices. the glazing comprises a sheet of colorless glass laminated with a colored glass sheet, and the one or more reflecting devices are oriented to reflect the light rays from the light emitting diode (LEDs) towards the colorless glass sheet. the reflective device (s) are configured to reflect and direct the visible and / or ultraviolet light rays into a beam showing an unfavorable angle with respect to the surface of the glass sheet traversed by the light rays. the reflective device (s) are configured to reflect and direct the visible and / or ultraviolet light rays into a beam showing a right angle to the surface of the glass sheet traversed by the light rays. the reflective device or devices are formed by a reflecting membrane having at least one relief forming an elliptical or truncated pyramidal paraboloid-shaped micro-reflector device. the membrane is a flexible metal membrane. the membrane is made of plastic material with at least one face capable of reflecting visible and / or ultraviolet light radiation, preferably the membrane is made of a polymer material capable of conducting heat. the heat conducting polymer material is a material comprising a thermoplastic polymer polymer matrix such as polycarbonate, polyethylene, or polypropylene, loaded with a heat-conducting material such as aluminum, copper, magnesium, or carbon. the membrane is in contact with one of the glass sheets and said glass sheet carries tracks, for example metal or conductive oxide type ITO (indium tin oxide), or a conductive layer of heat to diffuse the heat harvested by the membrane for evacuation by diffusion. the glazing has a thickness greater than or equal to 4.5 mm, preferably it has a thickness less than or equal to 7 mm. the glazing is mounted on a vehicle and the glass sheet carrying a diode supply circuit is the inner sheet, that is to say the sheet disposed in the passenger compartment. The outer sheet is in contrast, the sheet exposed to the outside of the vehicle. the diaphragm has an asymmetric shape acting as a key during its assembly in the glazing. The glazing is a windshield or a rear window of a vehicle or a side window of a vehicle or a panoramic roof of a vehicle.

The invention also relates to a reflective device comprising at least one micro-reflector for a glazing as defined above. The invention also relates to a remarkable vehicle in that it has a glazing as defined above. As will be understood from reading the definition that has just been given, the invention consists in a first aspect to provide a laminated light glazing, for which light is emitted directly into the glazing. The light is emitted in a direction opposite to its final direction and then sent back in its final direction by reflection. For example, if the light is intended to illuminate the passenger compartment of a vehicle then, at first, it will be emitted in a direction opposite to the passenger compartment and then be reflected, in a second step, in the direction of the vehicle. cabin by means of an optical device capable of concentrating the light rays and directing them in a given direction. The invention proposes to collect the light emitted by a diode to restore it as a collimated beam, that is to say, to concentrate and direct in a predefined direction. Preferably, the beams of the beam are substantially parallel. Thus, it is possible to emit light by controlling its diffusion so as to avoid the discomfort resulting from diffusion in all directions. The invention makes it possible, for example, to form a reading light in a luminous glazing unit. According to a second aspect of the invention, the light extracting device makes it possible to direct a light beam in a direction chosen to present either a right angle or a non-right angle, with the surface of the glazing. It then becomes possible to position the light extraction and scattering device at the edge of the glazing and to project the light beam by giving it an inclination with the face of the glazing from which it is emitted. The light beam can then be emitted at the edge of the glazing and be projected towards a relatively central position of the passenger compartment. As a result, the risk of dazzling passengers or the driver and / or the risk of reflection on the rearview mirror or on the dashboard is reduced. According to a third aspect of the invention, the light rays form a beam of concentrated rays whose luminous intensity is thus increased. It is therefore possible from a conventional light source to illuminate with greater intensity and dazzle less. According to a fourth aspect, the reflecting device is a membrane providing the dual function of reflector and heat sink collecting the heat emitted by the LEDs for its evacuation. According to a fifth aspect, the glazing comprises two superimposed lamination interleaves, one receiving the LEDs and the other receiving the reflecting device. The two dividers are perforated for this purpose. The recess presented by the spacer receiving the diodes is smaller than that receiving the reflective device in the form of a membrane so as to create a rim on which the reflective device rests and thus keep it at a certain distance from the LEDs. This arrangement is particularly advantageous for positioning the light flux generating element at the focal point of the microreflectors of the reflecting device on the one hand. It also preserves an electrically insulating air gap between the LEDs and the reflecting device acting as a heat sink. It will be appreciated that the use of micro-reflectors for directing or converging light is known. For example, the document EP1981147 relates to a 90 ° reflection device of a luminous flux emitted by an integrated LED between a transparent layer and a cover by a parabolic reflector. The LED is powered by an integrated conductive thin film. Finally, US2007002566 relates to a method of manufacturing an LCD screen comprising the integration of an LED on a transparent substrate and a reflector placed above the LED for reflection and concentration of light rays.

The invention will be well understood and other aspects and advantages will become apparent from the following description given by way of example with reference to the accompanying drawings in which: FIG. 1 shows a luminous glazing with a device light extractor according to the prior art; FIG. 2 presents a luminous glazing unit equipped with a luminous device according to the invention; Figure 3 illustrates the mode of operation of the invention; Figure 4 is another view of an exemplary embodiment of the invention. Figures 5 and 6 illustrate the possibilities of orientation of the light beam. In the various figures, the same references designate identical or similar elements. Figure 1 having been commented in part introductory, reference will now be made to Figure 2 showing an embodiment of the invention. FIG. 2 shows a luminous laminated glazing unit comprising an outer glass sheet 17 and a superimposed internal glass sheet 19, between which at least one laminating interlayer 21 made of plastic material is arranged. According to the invention, the glazing 15 comprises at least one light-emitting diode 23 or LED arranged facing at least one reflecting device 25. It will be noted that the invention is described in relation to a projection of visible light, but can be applied to other types of radiation such as ultraviolet radiation. Similarly, the invention is described in the context of a glazing forming the panoramic roof of a vehicle, but other applications can be envisaged. According to the invention, the LEDs 23 and the reflecting devices 25 are arranged at the level of the lamination interlayer 21, preferably in a recess of the lamination interlayer 21. As will be seen below, the LEDs can also, in known manner, be embedded in an electroconductive layer of polyethylene terephthalate (PET).

According to one embodiment of the invention, the LEDs 23 are fixed to a conductive circuit 27 carried by the inner sheet 19 and disposed on its outer face 29 (or first face) opposite to its inner face 31 (or second face ), that is to say on its face 29 in contact with the insert 21. The conductive circuit 27 is for example made of thin electrical son or a conductive layer carried by the glass sheet 19. This conductive layer can in known manner, be composed of conductive oxide such as a fluorine or antimony doped tin oxide (ITO) layer which has the advantage of being transparent to visible light. The conductive circuit 27 is supplied with electricity by power supply means 39 at the edge of the glazing 15.

The LEDs used in the context of the invention are small, preferably less than 1 mm, if possible less than 0.75 mm. If the size of the LEDs used so requires, the skilled person may choose to use lamination interleaves 21 showing a greater thickness than those conventionally used, that is to say a thickness greater than 0.76 mm, or two interposed sheets 21 superimposed between the internal glass sheets 19 and outer 17 are interposed. The important thing being understood is that the interlayer (s) 21 for lamination have a thickness greater than or equal to the thickness presented by the assembly. formed by the LEDs 23 and the reflective device or devices 25. It is indeed necessary to avoid, on the one hand any crushing of the LEDs 23 which would be likely to damage them, and on the other hand any crushing of the reflective devices 25 which would be likely to change their orientation or focus. The LEDs 23 are thus disposed on the outer face 29 of the inner sheet 19 and oriented so that the light flux generating element faces the outer sheet 17. It is understood that the luminous flux is oriented in an opposite direction at its final direction. For example, when the invention is applied to the formation of a reading light in a panoramic roof of a vehicle, the luminous flux is thus directed towards the outside of the passenger compartment and then reflected towards the passenger compartment. as we are going to see it now. At least one reflecting device 25 is arranged facing the LEDs 23, and interposed between the two sheets of glass at the level of the interlayer 21 lamination. The reflecting device or devices 25 comprise at least one micro-reflector 41 and preferably a plurality of micro-reflectors 41 aligned in a grid pattern or in any other arrangement that can be envisaged, for example in a circular arrangement. Advantageously, each micro-reflector 41 is associated with an LED 23 with which it is aligned. In the context of an application to a reader, the skilled person to have between 4 and 10 LEDs 23 in at least one circle, the LEDs 23 being separated by at least 1 cm to promote good heat dissipation that they produce. According to one preferred embodiment of the invention, the micro-reflectors 41 are reflective optical devices in the form of an elliptical paraboloid (or paraboloid of revolution) and capable of projecting light in a particular direction. Other forms are conceivable by those skilled in the art such as truncated pyramidal forms, for example. The important thing for the optical device is to reflect the light by focusing it and directing it in a given direction. The micro-reflectors 41 are dimensioned and positioned so that the LEDs 23 with which they are associated are arranged at their focus. In this way, the light emitted by the LEDs 23 is projected, by reflection, in a given direction, towards the inner sheet 19, so according to our example, towards the passenger compartment of the vehicle. The light rays are projected in the opposite direction to their direction of emission. The micro-reflectors 41 act as projectors directing the light they capture in a given direction.

In FIG. 3, we see how the light 35 is emitted from the LEDs 23 towards the micro-reflectors 25 to be reflected in the form of a collimated beam 37 towards the passenger compartment of the vehicle. According to a preferred implementation of the invention illustrated in FIG. 4, the reflecting device 25 comprising at least one micro-reflector 41 is for example formed of a flexible membrane. The micro-reflectors 41 form a relief on this membrane that can be obtained by punching. The membrane is a metal membrane or a plastic membrane of which at least one face is reflective. When it is made of plastic, the membrane is preferably made of a polymer material capable of conducting heat so as to evacuate the heat produced by the LEDs. For example, it is composed in known manner of a material comprising a polymer matrix of thermoplastic polymer such as polycarbonate, polyethylene, or polypropylene, loaded with a heat-conducting material such as aluminum, copper, magnesium , or carbon. This allows the membrane to act as a heat sink collecting and diffusing the heat emitted by the LEDs 23. The use of heat sinks will be considered by those skilled in the art if the number of LEDs employed is relatively high and / or if their respective spacing from each other is not sufficient to ensure a natural evacuation of sufficient heat to guarantee their performance. The laminating interlayer 21 is partially or completely perforated so as to accommodate the membrane having the reliefs forming micro-reflectors 41 and the LEDs 23 in a recess 33. The micro-reflectors 41 are positioned in the hollow volume 33 of the or interleaves 21 so that each LED 23 is disposed at the focus of one of the parabolic micro-reflectors. Preferably, the glazing comprises two superimposed lamination interleaves (21a; 21b). Thus, the LEDs 23 are disposed at a first laminating interlayer 21a and the reflecting device or devices 25 are arranged at a second laminating interlayer 21b. It will also be advantageous if the recess of the spacer 21a receiving the LEDs 23 is smaller than the recess 21b receiving the membrane of the reflecting device 25 so as to form a rim 43 for supporting the membrane. This arrangement is particularly advantageous in that it allows the creation of an air gap between the LEDs 23 and the heat conductive membrane of the reflecting device 25 which will isolate them electrically. Indeed, the membrane when it is metallic or coated with a metal reflective layer will not only be heat conductor but also electricity.

With two lamination interleaves (21a, 21b), the glazing has a thickness greater than or equal to 4.5 mm. Preferably, the glazing has a thickness of less than or equal to 7 mm, mainly in order to limit the weight that it can present. When the reflecting device 25 is formed by a punched membrane, it will advantageously have an asymmetrical shape and intended to take position in the openwork of the complementary form spacer sheet. This configuration facilitates the alignment of micro-reflectors 41 and LEDs 23. In a vehicle application, and particularly where the glazing constitutes a substantial part or even the entire surface of the roof of the vehicle, it is desirable to limit the energy intake from the outside of the vehicle to avoid heating up the passenger compartment and / or not unnecessarily soliciting the air conditioning installation which consumes a lot of energy. In known manner, for example from EP1200256, it is possible to color the glass sheets or to introduce reflective or absorbent interlayers.

Thus, when it is desirable to limit the energy input from outside the vehicle, it is possible in the context of the invention to color at least one of the glass sheets. Preferably, and for reasons of efficiency, only the outer sheet 17 will be colored. The inner sheet 19 through which the luminous flux is projected is preferably colorless. It will therefore be understood that the light-emitting diode supply circuit 27 is carried by the colorless glass sheet 19 through which the luminous flux is reflected. Similarly, the glazings according to the invention may also comprise functional layers such as, for example, absorbent and / or reflective antisolar layers 45. Such antisolar layers 45, for example based on tin oxides, are known to those skilled in the art and will not be described further herein. Note that in the variants of the invention where such a layer is present, it is disposed on the outer glass sheet 17 in contact with its face which after assembly of the glazing is not exposed to the surrounding air. The antisolar layer 45 is disposed between the intermediate layer 21b comprising the reflecting device 25 and the outer glass sheet 17 so as not to hinder the projection of light towards the passenger compartment. The presence of an antisolar layer 45 also contributes to the diffusion of the heat collected by the membrane of the reflecting device 25 for its evacuation. In the absence of an antisolar layer, the outer glass sheet 17, in contact with the membrane, carries tracks, may for example carry metal tracks, or a heat conductive layer in order to diffuse the heat collected by the membrane for its purpose. evacuation. As illustrated in FIG. 5, the micro-reflectors 41 can be oriented so as to reflect the light perpendicular to the internal sheet 19. It is also possible to configure or orient the micro-reflectors 41 so as to direct the light at a non-right angle with respect to the face 29 of the glass sheet 19 carrying the LEDs 23 as illustrated in FIG. is particularly advantageous for minimizing the possible annoyance generated by the light extraction and scattering means. These can indeed be offset from the place to illuminate within the cabin. According to an implementation not shown, the first lamination interlayer comprising the diodes is an electroconductive layer of polyethylene terephthalate (PET). The embedding of LEDs in an electroconductive layer of PET is a technology known to those skilled in the art which will not be described in detail herein. This first interlayer is then interposed between the second lamination interlayer and a third lamination interlayer PVB, TPU or EVA, materials that offer good adhesion to glass as PET. As already indicated, the invention is described in the context of the realization of a reading light on a panoramic glass roof, it has other applications such as for example a rear light formed on the rear window of a vehicle. In such a case, the reflecting devices and the LEDs are arranged to reflect the light beam towards the outside of the vehicle.

Claims (10)

REVENDICATIONS1. Laminated glass pane (15) comprising at least two sheets (17; 19) of glass separated by at least one interlayer (21) for lamination, the pane further comprising, at the level of the interlayer (21) for lamination, at at least one light-emitting diode (23) capable of emitting light rays (35), characterized in that the diode or diodes are arranged facing at least one reflecting device (25) configured to concentrate and reflect the rays (35) according to a given direction. 2. Glazing (15) according to one of claims 1 characterized in that the glazing comprises at least two lamination interleaves superimposed in that the light emitting diode (s) (23) are arranged at a first interlayer lamination and the at least one reflecting device (25) is disposed at a second lamination interlayer. 3. Glazing (15) according to claim 2 characterized in that the first lamination interlayer comprising the diodes is an electroconductive layer of polyethylene terephthalate, in that the first interlayer is interposed between the second lamination interlayer and a third interlayer lamination . 4. Glazing (15) according to claim 1 or 2, characterized in that the light emitting diode (s) (23) and the reflecting device (s) (25) are arranged in a recess of the insert (21). 5. Glazing (15) according to one of claims 1, 2 or 4 characterized in that one of the sheets (19) of glass carries, on its face (29) in contact with the interlayer (21) lamination, a circuit (27) for supplying the light-emitting diodes (23). 6. Glazing (15) according to one of claims 1 to 5 characterized in that the light emitting diode (s) (23) are oriented to emit their light rays (35) towards the reflective device or devices (25) 7. Glazing (15) according to one of claims 1 to 6 characterized in that the one or more reflecting devices (25) are configured to reflect and direct the visible light rays in a beam showing a non-right angle relative to the surface of the glass sheet (19) traversed by the light rays (35). 8. Glazing (15) according to one of claims 1 to 7 characterized in that the reflective device or devices (25) are formed by a reflective membrane having at least one relief forming a micro-reflector device shaped elliptical paraboloid or shaped truncated pyramid. 9. Glazing (15) according to claim 8 characterized in that the membrane is a flexible metal membrane or a membrane of plastic material with at least one face capable of reflecting a visible light radiation, preferably when the membrane is in a plastic material, it is made of a polymer material capable of conducting heat. 10. Vehicle characterized in that it comprises a glazing unit (15) according to one of the preceding claims.