DE102013009457A1 - Reflecting optical component for use as outside mirror in vehicle, has reflective layer or optical effective layer arranged on opposite side of surface heating, where optical effective layer is faced away from transparent covering layer - Google Patents

Abstract

The component (2) has a surface heating element (4) directly joined to a transparent covering layer (3) in the form of an electrical strip conductor. A reflective layer (5) or optical effective layer facing away from the transparent covering layer, is arranged on an opposite side of the surface heating element. The electrical strip conductor is formed in a form of a lattice. The optical effective layer is arranged between the surface heating element and the reflective layer, where the optical effective layer comprises an electrochromic layer structure. The optical effective layer comprises a layer structure with polymeric-dispersed liquid crystals. The transparent covering layer is made of a plastic or glasses.

Description

The invention relates to an optical component according to the closer defined in the preamble of claim 1. Art Furthermore, the invention relates to the use of such a reflective optical component.

Optical components are known from the general state of the art. They typically consist of a transparent cover layer, which can generally be made of glass or a transparent plastic material. Together with a reflective layer, they then form, for example, a reflective optical component. This can be used, for example, as a mirror. A preferred embodiment of such reflective optical components is their use as rearview mirrors, especially as exterior mirrors in vehicles. Here there is basically the risk of wetting with water, fogging or even icing of the reflective optical component, which is to be counteracted according to the prior art with a surface heating device. For this, see the US disclosure US 2013/0027952 A1 directed. There, and so it is with all other components of the general state of the art, the reflective optical component has a surface heating element. This is applied to the side facing away from the transparent cover layer on the back of the reflective layer. The overall structure of the reflective optical component can be heated so as to remove, for example, ice and / or water from the surface of the transparent cover layer and to ensure a good optical reflectivity of the component. The disadvantage of the design is that comparatively much electrical energy is needed to achieve just that. In addition to the transparent cover layer, which is actually intended to be heated, further layers, in particular the reflective layer and, if appropriate, further functional layers arranged therebetween, must also be heated. On the one hand, this leads to a high electrical energy requirement and, on the other hand, to a time delay until sufficient heating of the transparent cover layer to improve the optical reflection properties can be achieved.

Furthermore, optical components without a reflecting layer are known from the general state of the art. These components may in particular be components with an optically active layer or an optically effective layer structure. Such an optically effective layer structure in the sense of the invention is understood to mean a layer or a layer structure which is capable of actively changing, for example, the transparency, the color or both in the optically active layer structure. This can be done for example by applying an electrical voltage. Such optically active layers are for example in the DE 10 2011 015 949 A1 as well as the DE 10 2011 015 951 A1 described. In particular, in the latter document is described that the electrodes used to change the optical properties can also be used for heating. However, this has the disadvantage that along with the heating, there is the risk that the optical properties change, which is usually undesirable at this time.

The object of the present invention is now to avoid these disadvantages and to provide an optical component which ensures very fast and energy efficient improvement of the optical properties in the case of wetting with liquids and / or ice.

The object is achieved by an optical component having the features in the characterizing part of claim 1. Advantageous embodiments and further developments emerge from the subclaims dependent thereon. In addition, a particularly preferred use of the reflective optical component according to the invention is specified in claim 9. An advantageous development thereof can be found in the dependent subclaim.

In the case of the optical component according to the invention, provision is made for the surface heating element to be connected directly to the transparent cover layer in the form of at least one electrical conductor, wherein the reflective layer or the at least one optically active layer is arranged on the side of the surface heating element facing away from the transparent cover layer. By embedding the surface heating element between the reflective layer or the at least one optically active layer and the transparent cover layer, a very good heating of the transparent cover layer is achieved, since there is a direct heat-conducting contact between the surface heating element and this layer, without layers arranged therebetween.

Another advantage of the structure results in the case of a reflective layer in that the reflective layer is designed to be reflective in the direction of the transparent cover layer. Typically, this not only reflects light waves, but at least also a part of the heat generated by the surface heating element, so that a radiation of heat in the direction of the reflective layer and therethrough is approximately avoided. This also contributes to a very rapid and energy-efficient heating of the transparent cover layer.

According to a very favorable development of the optical component according to the invention, it is then further provided that the at least one electrical conductor track is designed in the form of a grid. Such a grid, in particular a grid of inert metal, can be applied in various ways, for example, to the back of the transparent cover layer. In particular, production methods such as sputtering, printing or even chemical or electrochemical deposition processes are conceivable.

In a very favorable development of this idea, it is provided that the strength of the electrical conductor track is selected to be so fine that it does not cause any optical damage. In particular, when using a metallic grid this can be applied in such a fine thickness on the back of the transparent cover layer that hardly measurable and not visible to the human eye impairments of transparency or reflection can be achieved. Nevertheless, a very durable and reliable heating of the reflective optical component via the surface heating element can be achieved via the metallic grid, which can be formed in particular from an inert material.

In a further very advantageous embodiment of the optical component according to the invention, it can now also be provided that at least one further optically active layer is provided, which is arranged between the surface heating element and the reflective layer. The structure of the optical component can thus comprise both at least one optically active layer or the optically active layer structure and the reflective layer. In addition to the reflective properties, therefore, actively variable properties such as color, transparency or the like can be present in the optical component. The fact that the surface heating element again directly follows the transparent cover layer and that at least one optically active layer is arranged between the latter and the reflective layer does not result in any disadvantages with regard to heating, since the at least one optically active layer does not hinder the heat flow to the transparent cover layer , In addition, the optically active layer may have its own functional elements, so that heating and switching of the optically active layer can be carried out independently of each other.

The optical element according to the invention can thus be put into a state in which a very good optical reflection and / or transparency is achieved very quickly and energy-efficiently, for example from wetting with liquid and / or an iced state. The component according to the invention is therefore particularly suitable as a trim panel or mirror in a vehicle, preferably as an exterior mirror, which is exposed depending on the weather again and again the risk of fogging and / or icing.

Further advantageous embodiments of the optical component according to the invention will become apparent from the remaining dependent claims and will be apparent from the embodiment, which is described below with reference to the figures.

Showing:

1 a schematic representation of an exterior mirror on a vehicle;

2 a schematic representation of a trim part made of transparent material on a vehicle;

3 a first possible layer structure of the optical element according to the invention;

4 a second possible layer structure of the optical element according to the invention;

5 a third possible layer structure of the optical element according to the invention;

6 a fourth possible layer structure of the optical element according to the invention; and

7 a fifth possible layer structure of the optical element according to the invention.

In the presentation of the 1 is an exterior mirror 1 represented as it may be arranged for example on a vehicle not shown in its entirety. The exterior mirror 1 includes an optically reflective component 2 which is typically movable in its angular position relative to the vehicle inside the exterior mirror 1 is arranged.

In the presentation of the 2 is a transparent trim part 1' represented for example of the vehicle, for example an outer pane or in particular a transparent roof element of the vehicle, which can be actively influenced by an optically active layer, for example in its transparency and / or color.

In the presentation of the 3 is a principle section through the optical component 2 to recognize. From top to bottom this consists of a transparent cover layer 3 a surface heating element 4 , which is in the form of a metal grid on the transparent cover layer 3 upset is. The structure is then covered by a reflective layer 5 completed. The surface heating element 4 in the form of the grid can be z. B. be formed as a lattice-shaped or meandering electrical conductor. The thickness of the trace, especially in the direction perpendicular to the direction in which the light passes through the transparent cover layer 3 on the reflective layer 5 is to be chosen so that an optical impairment is at most measurable, but not or barely perceptible to the human eye. In addition to the possibility of applying a metallic material, for example by sputtering, printing, in particular screen printing, or electrochemical or chemical deposition, there is also the possibility to use other materials, such as electrically conductive nanotubes, ceramics or the like.

The structure of the reflective optical component 2 as he is in the presentation of 3 can be seen, allows a very good and efficient heating of the transparent cover layer 3 if necessary, for example, because the transparent cover layer 3 wetted with liquid or iced, since a direct heat-conducting contact between the surface heating element 4 in the form of the grid and the transparent cover layer 3 is guaranteed.

In the following figures, this will now be in 3 explained construction of transparent cover layer 3 and directly arranged surface heating element 4 picked up again in the form of a grid, wherein at least one further optically active layer 100 or layered structures 100 between the reflective layer 5 or a transparent substrate S 'and the combination of transparent cover layer 3 and surface heating element 4 are arranged.

In the presentation of the 4 For example, a structure is shown in which is attached to the surface heating element 4 a transparent electrode 6 followed. On the transparent electrode 6 follows a functional layer 7 and another electrode 8th which, for example, also as a transparent electrode or in the form of a metallic grid, comparable to the surface heating element 4 , can be trained. This is followed by the reflective layer 5 or alternatively the transparent substrate 5 ' at. The functional layer 7 For example, it may now comprise polymer-dispersed liquid crystals, electrochromic layers based on viologens or suspended particles, which depend on one at the electrodes 6 . 8th For example, align the voltage applied to the transparency of the functional layer 7 and optionally to influence its color in the desired manner. This structure closes between the reflective layer 5 or alternatively the transparent substrate 5 ' and the surface heating element 4 to this, so that it can be used and used without the direct heating of the transparent cover layer 3 through the surface heating element 4 adversely affect.

In the presentation of the 5 is a similar structure to recognize. The functional layer 7 is divided into three individual layers, namely an electrochromic layer 9 , in an ion-conductive layer 10 For example, in the form of a liquid, a solid or a polymer, as well as in an ion storage layer 11 , Again, the structure of the other electrode 8th and the reflective layer 5 or alternatively the transparent substrate 5 ' completed.

In the presentation of the 6 is in turn a comparable structure as in the representation of 4 to recognize. In addition to the in 4 described structure is an intermediate layer 12 between the surface heating element 4 and the transparent electrode 6 to recognize. This intermediate layer may be formed, for example, as a protective layer or release layer. It can alternatively or additionally be used as a bonding layer, for example as an adhesive layer for bonding the components.

In the presentation of the 7 Finally, the same structure is again shown, in addition to the intermediate layer 12 between the intermediate layer 12 and the transparent electrode 6 an independent adhesive layer 13 is arranged.

The described optically active or functional layers 7 For example, with electrochromic layer structure or polymer-dispersed liquid crystals in the layer structure can be combined with each other arbitrarily, whereby the number of layers relative to the embodiments shown here increases accordingly. However, all of this is within the skill and skill of the artisan.

With regard to the exact functionality of, for example, the electrochromic layer structures or other types of layer structures operating, for example, with polymer-dispersed liquid crystals, reference is made to the general state of the art and, in particular, to US Pat DE 10 2011 015 951 A1 the applicant with respect to the electrochromic layers and on the DE 10 2011 015 949 A1 by the Applicant with regard to the functional layers with polymer-dispersed liquid crystals.

All described layer structures and their characteristics such as intermediate layers 12 and / or adhesive layers 13 can be thereby arbitrarily combine with each other. Of course, intermediate layers in the form of adhesives or the like are also possible and conceivable here.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2013/0027952 A1 [0002]
• DE 102011015949 A1 [0003, 0031]
• DE 102011015951 A1 [0003, 0031]

Claims (10)

Optical component ( 2 ) with a transparent cover layer ( 3 ), with a surface heating element ( 4 ), and with a reflective layer ( 5 ) or at least one optically active layer ( 100 ), characterized in that the transparent cover layer ( 3 ) the surface heating element ( 4 ) directly in the form of at least one electrical trace, wherein the reflective layer ( 5 ) or the at least one optically active layer ( 100 ) on the transparent cover layer ( 3 ) facing away from the surface heating element ( 4 ) is arranged Optical element ( 2 ) according to claim 1, characterized in that the at least one electrical conductor track is designed in the form of a grid. Optical element ( 2 ) according to claim 1 or 2, characterized in that the thickness of the at least one electrical conductor track is chosen so that it does not cause visual impairment. Optical element ( 2 ) according to claim 1, 2 or 3, characterized in that at least one optically active layer ( 100 ) is provided, which between the surface heating element ( 4 ) and the reflective layer ( 5 ) is arranged. Optical component ( 2 ) according to one of the preceding claims, characterized in that the at least one optically active layer ( 100 ) has an electrochromic layer structure. Optical component ( 2 ) according to one of the preceding claims, characterized in that the at least one optically active layer ( 100 ) has a layer structure with polymer-dispersed liquid crystals. Optical component ( 2 ) according to one of the preceding claims, characterized in that the at least one optically active layer ( 100 ) has a layer structure with susceptible particles which can be oriented by electrical voltage. Optical component ( 2 ) according to one of claims 1 to 7, characterized in that the transparent cover layer ( 3 ) is formed of a plastic or glass. Use of the optical component ( 2 ) in a vehicle. Use according to claim 9, characterized in that the optical component ( 2 ) as exterior mirrors ( 1 ) is used.

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