EA012744B1 - Automotive glazing - Google Patents

Abstract

The present invention relates to automotive glazing and particularly to glazing for sunroofs and glazing placed on tailgates or as rear windows, which glazing includes electroluminescent elements. The glazing comprises at least one rigid sheet of mineral or organic glass and at least one sheet of a thermoplastic bonded to the rigid sheet. It includes a set of light-emitting diodes incorporated into the thermoplastic sheet(s), the diodes being supplied by means of metal wires having a diameter of less than 300 mkm, which wires are also incorporated into the thermoplastic sheet(s).

Description

The present invention relates to automotive glazing elements, in particular to the elements of the glazing of the roof, as well as the glass units of the door of the rear wall of the body or the rear window of the car.

More specifically, the present invention relates to methods for incorporating light-emitting elements into said glazing elements.

The use of LEDs in automotive glazing elements has been previously demonstrated in a large number of examples. In particular, this refers to the installation of these LEDs to display information regarding the performance of the vehicle, and in this case the LEDs are mounted on the windscreen of the vehicle. In addition, this relates to the creation of a light source, in particular, installed in the roof structure.

The choice of LEDs for these applications is explained, first of all, by the task of enabling a display device in glass without the need for relatively complex technical solutions, including so-called dashboards on the windscreen. Secondly, traditional lighting devices cannot be embedded in glazing elements without affecting such an aesthetic parameter as transparency, which is the reason for choosing a glazed roof for this purpose, and the use of LEDs is chosen as a way to preserve transparency as much as possible.

In addition to the principles of using such LEDs, various questions arise, in particular, regarding the method of embedding LEDs or supplying power to them. In the two cases described above, it was proposed to embed the LEDs in a multi-layered glazing and supply them with power, essentially using transparent conductive layers. The choice of this method is easy to explain if the glazing elements in question already have coatings of such layers to give them certain characteristics, regardless of the presence of LEDs. In particular, this is the case with the device conductive layers, which, as you know, have the property of filtering solar radiation, significantly reducing the proportion of transmitted infrared rays, or serve as a means of heating the glazing elements.

In practice, not all glazing elements are equipped with such conductive layers. In addition, the incorporation of LEDs into these layers requires very careful assembly and the same careful organization of the power supply circuits, as described, for example, in European patent application no. EP 1437215 A1, Οία соπμ sshrgd and 1shopi and 8th esp1 (Glazing element containing the light element).

The present invention is to provide glazing elements containing groups of LEDs, which are relatively more convenient in production and are well combined with current leads that are compatible with those that are necessary, in particular, to connect the interior lighting of the vehicle.

According to the present invention, the glazing comprises at least one rigid sheet of mineral or organic glass and at least one sheet of thermoplastic material glued onto the rigid sheet. The LEDs are embedded in a sheet of thermoplastic material and supplied with power using metallic conductive wires, which are also included in the sheet of thermoplastic material.

It is known the production of automotive glazing elements with conductive wires included in them with the formation of a heating system. Such structures are used, in particular, as anti-icing or anti-defogging windshields in certain vehicles. This solution is chosen as an alternative to using thin heating layers that present difficulties in assembly, in particular, in the case of glazing elements of large dimensions, which, at a thickness that still provides sufficient light transmission, have very high resistance, with the result that the power of such a heating device becomes incompatible with used voltage.

However, inserting wires into the windshield is not the preferred solution. The presence of even extremely thin wires in the driver’s field of view is undesirable, especially if such wiring covers virtually the entire area of the windshield. However, the present invention does not impose such limitations.

In the main use cases, the LEDs are embedded in the double-glazed windows or glazing elements that are not directly in the field of view of the driver. In particular, this applies to the glazing of the roof, as well as to the rear windows. In addition, in the latter case, the presence of wiring causes fewer complaints from users, for whom the presence of an anti-icing net on the rear window of a car with a wire section much larger than the metal wiring section assumed in the present invention is customary. In the case of the roof glazing, the presence of wiring is not very noticeable, because, in addition to the fact that the roof glazing is not in the driver’s constant field of vision, the glazing elements used to make ceiling glazing have a reduced light transmission of about 30% or less, which is done in particular, in order to reduce the inconvenience associated with exposure to sunlight. In such light transmission conditions, the contrast created by the wires is less noticeable.

Regardless of the above, it remains preferable to use the wiring as little as possible.

- 1 012744 possible cross-sections with simultaneous provision of sufficient conductivity to exclude local heating, which, together with the heating caused by the operation of the LEDs, can cause the temperature to rise to a level dangerous for the thermoplastic material in which the LEDs and lead wires are embedded. In practice, these wires have a diameter of not more than 300 microns, preferably not more than 200 microns. In the most preferred embodiment, the current lead wiring of the LEDs has a diameter of about 20-100 microns.

Although it is preferable to use the thinnest wires to reduce their negative impact on the driver's view, it is also preferable to ensure that the wiring has a tensile strength sufficient to resist the mechanical stresses arising in the applications described below.

In the previous method, provided for embedding the LEDs with the power supplied by the circuits formed from the conductive layers, it is obvious that these layers themselves are not able to withstand the load of the LEDs. In other words, the connection of the LEDs with the power source should be carried out after ensuring the mechanical amplification of the conductive layers by connecting them with other elements of the structure. When connecting the LEDs to the power source in such conditions, a rather complicated task is to install the LEDs in the desired position relative to the power circuits.

The present invention allows to overcome these obstacles, in particular, when installing a large number of LEDs. In this case, it becomes possible and preferable to go directly to creating groups of LEDs on the same lead wire before embedding the specified wire into a thermoplastic material. The connection of the LEDs in these conditions is carried out with all the necessary accuracy and without the danger of installing the LEDs in the wrong position relative to the power circuit.

Creating groups of LEDs has the added advantage of allowing these wires to be placed in a thermoplastic material in this way and using such tools that were traditionally used previously for embedding heating wires as described above.

In accordance with one embodiment of the present invention, the glazing constitutes the rear window or glass of the vehicle rear wall door, and the LEDs in it form brake lights, turn lights, parking lights or alarms.

Below, the present invention will be described with reference to the drawings, in which FIG. 1 shows schematically a typical glazing structure of the present invention;

in fig. 2 is a diagram showing a practical example of embedding wires with LEDs in a sheet of thermoplastic material;

in fig. 3 - a variant of the arrangement of the lead wires with an installed group of LEDs; in fig. 4 is a schematic sectional view of an embodiment of a glazing according to the invention;

in fig. 5 is similar to FIG. 4 shows another embodiment of a glazing according to the invention.

FIG. 1 shows a glass unit with a detailed image, clearly illustrating the mutual arrangement of the various components that form part of the glazing element. In the depicted embodiment, said glazing contains two rigid transparent sheets (1, 2) of mineral or organic glass. These sheets in the glazing are connected using a thermoplastic intermediate layer 3 in accordance with standard methods for producing laminated glazing. According to the present invention can be used material traditionally used for this purpose. Such materials include polyacetals, in particular polyvinyl butyral resin (PVB), as well as polyvinyl chloride (PVC) or ethylene vinyl acetate (EVA).

After assembly, the sheets of intermediate layer 3 connecting the two rigid sheets (1, 2) remain the same perfectly transparent.

Sheets of glass can be either colorless or colored. In particular, if the glazing forms the roof or part of the roof of the vehicle, usually colored sheets of glass are used with limited light transmission, or, for example, the maximum limited transmission of energy. The latter quality usually refers to glazing with intense color, for example, due to the presence of a relatively high iron concentration. The intermediate layer (3) can also be colored.

In the embodiment shown in FIG. 1, the glazing is intended to form the roof of the vehicle, and the LEDs form the light source of the passenger compartment. To this end, the LEDs (5), each of which has a limited power, are installed in the position of the interior lighting. This method of installation, which in traditional embodiments using incandescent bulbs implies essentially the point-like nature of the light source, can obviously be changed, since the LEDs do not need to be installed in a limited area. The preferred option may be the distribution of these light sources formed by LEDs, for example, in such a way that they cover a significant part of the surface of the glass unit. This installation option is particularly preferred in cases where a light source with a reduced level of glare or even a light source that provides softer illumination is needed.

- 2,012,744 spaces. In such cases, the installation of the LEDs can be evenly distributed over the surface or part of the surface of the glazing, and can their location relative to each other to form patterns.

Depending on the type of light used or its application, in addition to installing LEDs, the right choice of their relative output power is important. In the case of daylight sources, it is preferable to use a significant number of distributed LEDs, each of which may have limited output power. For example, in the case of lighting a car roof, each of the LEDs used creates a luminous flux, preferably not exceeding 3 lm, more preferably not more than 1 lm. In the case of a more local light source, such as a spot or a limited number of LEDs, such as a door-closing indicator, light sensors, etc., the diodes preferably have a significantly higher output power. For example, such diodes can create a luminous flux from 5 to 25 lm, preferably from 10 to 20 lm.

In the embodiment shown in FIG. 1, the LEDs (5) are located in groups along the lead wires (4). These lead wires, in turn, are connected to conductors 6 located on both sides of the glazing. These conductors (tires) are formed in the traditional way either by wires, strips or also enamel conductors. In the latter case, they are located on the glass sheet (1), and not on the intermediate layer (3), as shown in the figure.

The contact between the wires (4) and the conductors (6) is provided in the traditional way by using a conductive adhesive, by welding or simply by connecting the edges of the wires (4) under pressure when assembling the sheets.

FIG. 4 shows a sectional view of the construction of various elements forming the glazing assembled. In the case shown, LEDs (5), the thickness of which is chosen so that it does not exceed the thickness of the intermediate layer (3), are embedded in the thermoplastic material of the specified sheet. Due to its plasticity, the material during assembly undergoes a change in shape in accordance with the LEDs built into it without the formation of air cavities and bubbles. The small LEDs are fully covered by the material of the intermediate layer.

FIG. 4 shows a group of 5 series-connected LEDs connected to the same lead wire 4. If several groups of series-connected LEDs are located close to each other, as shown in FIG. 1, it becomes possible to position the LEDs along two adjacent wires. In other words, the LEDs will be arranged in parallel. However, this accommodation option is not preferred. Individual characteristics of standard LEDs may differ significantly from each other either initially, or accumulate such a difference in the process of operation. Under these conditions, it becomes possible to visually distinguish their individual brightness. Although this possibility does not adversely affect the realization of the function of a group of LEDs as a source of illumination, from an aesthetic point of view, it is preferable that all LEDs in a design have almost the same visible characteristics during their operation. For this reason, it is preferable to arrange the diodes in series-connected groups. This will provide the same intensity of all the LEDs installed along the same wire and, therefore, in essence, the same brightness.

If the LEDs are connected in series, one failed LED may render the entire group inoperative. In practice, this possibility is unlikely. The principle of operation of LEDs, in contrast to incandescent bulbs, involves a gradual decrease in output power during operation. In addition, this degradation is extremely slow. The reduction in power by half is observed after several tens of thousands of hours of operation of the LED. Therefore, the likelihood of any malfunction due to degradation of the LED, as a rule, is absent.

If a fault occurs, it is most likely due to an external defect, such as an assembly defect. To avoid this situation, each LED can, for example, be divided into two. In this case, each LED turns on in parallel with the same LED along the same wire. In order to avoid the appearance of a noticeable difference in brightness, in this case it is preferable to ensure that the power allocated by each LED does not exceed half of its rated power. In the event of a fault in one of the LEDs in the pair, the power of the remaining LED will essentially compensate for the difference, approximately reaching the power of a pair of LEDs in the same sequential group.

The configuration of the carrier wires of the LEDs should preferably be formed before embedding in the intermediate sheet. Preferably, the LEDs are fixed on the lead wire (4) as shown in FIG. 3. Fastening is carried out in the traditional way, for example, using a conductive adhesive or welding with the LED contacts (10). As a rule, it is easier to fix the LEDs on a continuous wire, as shown in FIG. 3, than to collect a sequence of LEDs from several pieces of lead wires. Obviously, performing this operation requires

- 3 012744 would have to cut the wire, as can be seen from position (11) in FIG. 4, between the two contacts (10) of each LED. The wire can be initially manufactured with gaps in the intended installation locations of the LEDs, but before embedding into the intermediate layer. You can also cut (11) the wire after the wire and LEDs are laid in the intermediate layer. The first method of cutting is very convenient and eliminates the possibility that can lead to accidental shorting of the LEDs.

Regardless of the method chosen, embedding into the intermediate layer can be carried out in the manner previously used for embedding the heating wire. As an example, this method is schematically depicted in pos. 1 in FIG. 2

In accordance with this method, the intermediate layer is wound on a drum (7), possibly together with previously laid conductors on it (6). Wires (4) with installed LEDs (5) are unwound under tension from a coil (8). To facilitate the embedding of wires and LEDs in the intermediate layer, their preheating is possible. The coil (9), which forms a calender with the drum (7), is also preferably used to press wires and LEDs into the thermoplastic material of the intermediate sheet.

In the above illustration, the assembled from the wire structure is embedded in the intermediate sheet during a single operation, but the wires can also be embedded one by one.

After the wires with the LEDs are embedded in the thermoplastic material, the intermediate sheets (3) are connected to the rigid sheets in the traditional way, for example by heat treatment under pressure. The temperatures used for the assembly ensure the final melting of the LEDs into the thermoplastic material while simultaneously interconnecting the sheets.

Another way to embed wires with LEDs in a thermoplastic material, not shown in the illustrations, is to lay the wires with LEDs on the intermediate sheet to form the required shape, and the connection is made locally, for example, by spot welding the intermediate sheet along the contours of the wires. Wires, fixed in their positions on the intermediate sheet by such welded points, can be immediately sent to the operation of joining the sheets, during which the pressure and temperature will lead to their inclusion in the intermediate sheet.

The multilayer composition, shown in detail in FIG. 1 and in the roof lighting embodiment of FIG. 4, involves the installation of LEDs in such a way that their light is directed into the interior of the vehicle. For this purpose, light-emitting diodes with mirror-like working surfaces are used, which ensures the direction of the whole world, in the case shown in the illustration, towards the glass sheet (2). On the contrary, if we are talking about a stoplight or other light indicator, for example, mounted on the rear window or the glazing of the rear door (fifth door), the light emitted by the LEDs is directed exclusively outwards. In commercially available LEDs, there are both versions of the orientation of the mirror surfaces.

FIG. 4 shows an assembled glazing element comprising an intermediate sheet (3). The thickness of the intermediate sheet, which can be achieved by modern industry, is less than 1 mm. In particular, PVB sheets are available in 0.38 and 0.76 mm thick. The LEDs used in the preferred embodiment should be less than 0.5 mm thick. To ensure their proper incorporation into the thermoplastic material, its thickness should obviously be at least equal to or somewhat greater than this value.

Regardless of the method of assembly of the glazing elements of the present invention, they all necessarily include the application of pressure to the sheets forming the assembly, and the mechanical stresses applied to the LEDs should not lead to the possibility of degrading their characteristics. From this point of view, it is preferable to ensure that the thickness of the intermediate sheet or sheets is at least 20% greater than the thickness of the LEDs. The specified margin of thickness prevents crushing of the LEDs between the sheets during assembly. The essence of the assembly method also implies the existence of rather strong mechanical stresses. Depending on the size, shape and type of glass, they can undergo calendering, vacuum compression, etc. The pressures applied during calendering are such that, with a high degree of probability, excessive local mechanical stresses in groups of LEDs can be caused. In this case, the thickness of the intermediate layers in practice should be greater than the thickness of the LEDs. In the methods involving a slight compression of the collected sheets, a more uniform distribution of mechanical stresses occurs, and the thickness of the intermediate layers may be closer to the thickness of the LEDs.

Assembly may also be carried out with one or more sheets of thermoplastic material. In the case of two intermediate sheets (the method is not shown in the illustration), wires with LEDs are preferably laid between these two sheets. Thus, it will allow embedding of the LEDs into the thermoplastic material in a reliable manner.

Although the glass packs of the present invention most often consist of two rigid sheets (1, 2), it is also possible to assemble one rigid sheet with two or more sheets of flexible material. There is a similar method of manufacturing products, commonly referred to as double-layer glazing.

- 4 012744

The flexible material is polyurethane, for example, one that, along with its flexibility, can also have good scratch resistance or self-cleaning properties.

Other materials are also suitable for use in assembly with only one rigid sheet (1). FIG. 5 shows a schematic sectional view of a material of this type, for example, in addition to a rigid sheet, a sheet of material traditionally used for making multilayer compositions, in particular a PVB sheet (3), the sheet being protected from scratching from the side opposite to the rigid sheet (1), more rigid protective layer (12). The specified layer is preferably made of polymer and has a sufficiently small thickness to repeat the shape of a rigid sheet, which determines the overall shape of the product. Sheets (3) and (12) are produced industrially in a pre-assembled form, for example, as in the case of a product sold by ϋυροηΐ. Obviously, it is possible to assemble several separate sheets. In all these cases, the embedding of wires and diodes carried out by the methods described above.

Claims (9)

CLAIM 1. Automobile glazing comprising at least one rigid sheet of mineral or organic glass and at least one sheet of thermoplastic material glued to said rigid sheet, said glazing comprising a set of LEDs included in thermoplastic sheet (s), characterized in that LEDs are powered by metal wires having a diameter of less than 300 microns, and the wires are also included in the thermoplastic sheet (s). 2. Glazing according to claim 1, characterized in that the LEDs are located in the form of one or more connected groups along the lead wire. 3. Glazing according to claim 2, characterized in that said current-carrying (e) wire (a) and the LEDs that they supply with power are included in the sheet (s) of plastic material by calendering. 4. Glazing according to claim 3, characterized in that the wires and LEDs that they supply are included in the thermoplastic sheet (s) during the operation prior to assembly with a rigid sheet or sheets of mineral or organic glass. 5. Glazing in one of the preceding paragraphs, characterized in that the lead wires continue from one edge of the glazing to the other and are connected to power contacts located along the edges of the glazing. 6. Glazing according to one of the preceding paragraphs, characterized in that said LEDs are arranged in pairs arranged parallel to the lead wires. 7. Glazing in one of the preceding paragraphs, characterized in that the thermoplastic (e) sheet (s) connects (s) two sheets of organic or mineral glass. 8. Glazing in one of the preceding paragraphs, forming part of the roof of the car, characterized in that the LEDs form the source of the internal lighting of the vehicle. 9. Glazing according to one of claims 1 to 7, forming a rear window or a fifth door glazing, characterized in that said LEDs form brake lights, turning lights, parking lights or alarms.