EP1934066A1

EP1934066A1 - Layer arrangement for darkening a transparent pane

Info

Publication number: EP1934066A1
Application number: EP06805427A
Authority: EP
Inventors: Ismail Cuma
Original assignee: Webasto SE
Current assignee: Webasto SE
Priority date: 2005-10-13
Filing date: 2006-10-13
Publication date: 2008-06-25
Also published as: US20080264466A1; WO2007042019A1; DE102005049081B3

Abstract

A layer arrangement for darkening a transparent pane (4), in particular a motor vehicle window pane, so as to offer protection from incident light (5), comprises: at least one first photovoltaic layer (1; 1a, 1b) with a high degree of light absorption, at least one second photovoltaic layer (2) with a high degree of light absorption and a high degree of light reflection, arranged behind the at least one first photovoltaic layer (1; 1a, 1b), in the direction of incidence of the incident light (5), at least one active insulating layer (3; 3a, 3b) with an electrically variable degree of darkening, and arranged behind the at least one second photovoltaic layer (2), in the direction of incidence of the incident light (5), and a controller for electrically controlling the degree of darkening of the at least one active insulation layer (3; 3a, 3b) using the electric energy generated by the at least one first photovoltaic layer (1; 1a, 1b) and/or the at least one second photovoltaic layer (2).

Description

Layer arrangement for darkening a transparent pane

The present invention relates to a layer arrangement for darkening a transparent pane or foil, in particular a motor vehicle pane, for protection against incident light.

Although applicable to any disc, the present invention as well as its underlying problem with respect to a motor vehicle window and in particular with respect to a windshield of a motor vehicle are explained in more detail.

To prevent the incidence of light through a transparent pane in the eyes of people who run or use a motor vehicle, facilities such. As sun visors, sun blinds, dark adhesive films for transparent glass, tinted windows, glare or sunglasses.

However, such devices all have specific disadvantages, such. B. unchangeable light attenuation, complete darkening of the entire area of a transparent pane by coloring or tinting, complete optical suppression by the dimming, such as sunglasses, which causes a darkening even in unwanted areas. Other disadvantages are the cumbersome handling and the disturbing design of some of these facilities.

In addition, the sun visor or sun blind in a motor vehicle takes the upper field of view completely out of sight, so that signals or the like can be overlooked. This can lead to dangerous traffic situations.

Another disadvantage of transparent and / or tinted windows is that they the interior of the vehicle in intense sunlight, especially during the day Vehicles parked outdoors, heat up enormously, especially since conventional sunscreens only partially cover the disc surfaces.

Furthermore, a protection against external view into the interior of the motor vehicle can currently only by Innenver- reflections, d. H. semi-permeable mirror surfaces, by intensive tinting of the windows or by internal curtains or blinds can be achieved. Removing this protection during driving for safety-relevant windows is impossible with mirrored and tinted windows and can only be achieved with mechanical aids, such as sun visors, roller blinds or blinds, with great expenditure of time and traffic-deflecting movements.

From document DE 2 421 486 B2 an anti-glare device is known in which in a partial area of a windscreen of a motor vehicle the light transmission can be regulated with high speed as a function of the brightness of an external light source. In this case, a phototransistor, which is arranged outside the pane, detects the light of an oncoming vehicle. The windshield is formed in the liquid crystal region whose light transmittance is controlled by the phototransistor. Since the phototransistor detects no directional dependence on the incident light, it detects the entire ambient light and thus controls the intended windshield area dark.

However, this approach has proved to be disadvantageous in that the phototransistor for detecting the incident light needs to be mounted outside the disk and thus cumbersome and costly. Furthermore, additional energy sources are necessary to control the liquid crystal.

The present invention is based on the object, a device for protecting a transparent pane or film indicate in front of incident light, which can be produced inexpensively, which can be easily integrated and their protective effect in dependence of the incident light is controlled.

This object is achieved by the layer arrangement with the features of claim 1.

The idea underlying the present invention is that the layer arrangement for darkening a transparent pane to protect against incident light at least a first photovoltaic layer having a high degree of light absorption; at least one second photovoltaic layer having a high degree of light absorption and a high degree of light reflection, which is arranged in the direction of the incident light behind the at least one first photovoltaic layer; at least one active insulation layer with an electrically variable darkening degree, which is arranged in the direction of the incident light behind the at least one second photovoltaic layer; and a control device for electrically controlling the degree of darkening of the at least one active insulation layer using the electrical energy generated by the at least one first photovoltaic layer and / or the at least one second photovoltaic layer.

Thus, the present invention over the known approaches in the prior art has the advantage that no additional energy sources for driving the at least one active insulating layer for a change in the dimming level of the same are necessary because the electric

Energy is generated by the photovoltaic layers and used for the control. Furthermore, the photovoltaic layers have a dual function, since they on the one hand absorb the incident light radiation into electrical energy and on the other hand already absorb and / or reflect a certain percentage of the incident radiation and thus already ensure a predetermined darkening of the transparent pane. In addition, the layer arrangement of the present invention can be formed as a thin film, which can be attached, for example, in a simple and cost-effective manner on a disc to be darkened.

In the dependent claims are advantageous embodiments and improvements of the claim 1 layer arrangement.

According to a preferred refinement, a plurality, preferably two to three, first photovoltaic layers are provided successively in order to increase the total amount of light absorbed. As a result, on the one hand, a predetermined darkening and, on the other hand, a sufficient amount of electrical energy are created.

According to a further preferred development, a plurality, preferably two to three, second photovoltaic layers are used to increase the total absorbed and reflected

Amount of light (photons, light quanta) provided sequentially. This can also increase the degree of darkening and the amount of electrical energy generated.

According to a further preferred embodiment, the at least one photovoltaic layer and / or the at least one second photovoltaic layer each consist of at least one suitably doped semiconductor material, for example of silicon, germanium or the like. The material of the at least one first photovoltaic layer has in particular a high degree of light absorption, wherein the material of the at least one second photovoltaic layer preferably has a high degree of light absorption and a high degree of light reflection such that reflected light passes through the at least one first photovoltaic layer again is reflected through to generate additional electrical energy. According to a further preferred development, the at least one first photovoltaic layer and / or the at least one second photovoltaic layer each have a nano and / or a pikomaterial and / or an even smaller material. As a result, the photovoltaic layers can be formed in such a finer and improved manner that the amount of light absorbed and thus the current generated and the degree of darkening can be increased in comparison to an embodiment with a micromaterial.

Advantageously, several, for example, two to three active insulation layers to increase the Gesamtabdunklungsgrades successively provided. Advantageously, all insulation layers are controlled by using the energy generated at the photovoltaic layers by a common control device as a function of the incident light.

Preferably, the at least one active insulation layer is formed as a semiconductor layer. By way of example, the active insulation layer may be in the form of an organic light-emitting diode (OLED), in the form of a light-emitting diode (LED), an LCD and / or a mixture of substances provided for this purpose. Such organic light-emitting diodes are good insulators and particularly suitable for darkening. The at least one active insulation layer may advantageously have a nano and / or a pico material and / or an even smaller material.

According to a further preferred embodiment, the layer arrangement can be fastened on a transparent pane, for example by means of a suitable adhesive connection. Alternatively, the layer arrangement can also be integrated in a pane, for example, the layer arrangement can be laminated or embedded in the pane.

The invention is explained in more detail below on the basis of exemplary embodiments with reference to the accompanying figures of the drawing. From the figures show:

FIG. 1 shows a cross-sectional view of a layer arrangement applied on a pane according to a first preferred embodiment of the present invention; and

FIG. 2 shows a cross-sectional view of a layer arrangement applied on a pane according to a second preferred embodiment of the present invention.

In the figures, the same reference numerals designate the same or functionally identical components, unless indicated otherwise.

The figures illustrate cross-sectional views of inventive layer arrangements according to preferred embodiments of the present invention, which on a transparent

Disk 4 of a motor vehicle are preferably glued by means of a suitable adhesive. In the exemplary embodiments, the arrows denoted by the reference numeral 5 designate the direction of the incident light, for example the incident sunlight. Furthermore, in the exemplary embodiments, the layer arrangements are accordingly arranged on the outside of the transparent pane 4 in the direction of the incident light 5. However, it is obvious to a person skilled in the art that the layer arrangements can also be mounted analogously on the inside of the pane 4 or can be laminated into the pane 4 in the case of a pane of glass pane.

According to a first preferred embodiment according to FIG. 1, the layer arrangement for darkening the transparent pane 4 consists of a first photovoltaic layer 1 which represents the foremost one in the direction of the incident light 5 or the uppermost layer in FIG. The entire layer arrangement is formed for example as a thin film, which can be easily glued to the transparent pane 4 or laminated or embedded in the transparent pane 4.

The first photovoltaic layer 1, d. H. The solar cell layer 1 serving essentially as an energy converter preferably consists of one or more semiconductor elements, such as silicon, germanium or the like. The semiconductor elements are appropriately doped in a conventional manner such that a predetermined percentage of the incident light 5 is converted into electrical energy or heat energy. The operation of such solar cells together with the energy-absorbing device is well known in the prior art, so that a detailed description thereof can be dispensed with.

The first photovoltaic layer 1 is further preferably designed such that it has a high degree of light absorption in order to convert a predetermined portion of the incident light 5 into electrical energy.

As can be seen in FIG. 1, a second photovoltaic layer 2 is arranged behind the first photovoltaic layer 1 in the direction of the incident light 5, which likewise advantageously has a high degree of light absorption and a high degree of light reflection, on the one hand a predetermined proportion of the incident light 5 passing through the first photovoltaic layer into electric energy and, on the other hand, reflecting a portion of the incident light 5 toward the first photovoltaic layer 1, so that the first photovoltaic layer 1 additionally has a proportion thereof by scattering or refraction absorb reflected radiation and convert it into electrical energy. This increases the efficiency of the layer arrangement.

The second photovoltaic layer 2 is analogous to the first photovoltaic layer 1 preferably one or more formed semiconductor elements, for example, again suitably doped silicon or germanium can be used.

The photovoltaic layers 1 and 2 each serve for a light absorption for the generation of electrical energy or heat energy and for darkening the transparent pane 4.

In particular, the charge carrier layers of the two photovoltaic layers 1 and 2 are each preferably produced by means of nano and / or picotechnology and / or even smaller technologies, ie. H. at least the p-n layers of the photovoltaic layers 1 and 2 have nano- and / or pico particles and / or even smaller particles. As a result, a larger portion of the incident radiation 5 can be absorbed as compared with the conventional microtechnology because of the smaller size of the particles and thus smaller interparticle space, so that the efficiency of the photovoltaic layers 1 and 2 is increased over the commonly used micro-technology can. It is obvious to a person skilled in the art that instead of nanotechnology, it is also possible to use picotechnology or, if appropriate, also microtechnology, or that several layers with differing particle configurations can be provided in succession. Furthermore, layers comprising a mixture of femto, pico, nano and / or microparticles or even smaller particles may be used. Advantageously, the photovoltaic layers 1 and 2 are designed such that the efficiency, d. H. the generated electrical energy is optimized.

According to the first exemplary embodiment according to FIG. 1, the layer arrangement has an active insulation layer 3 behind the second photovoltaic layer 2 in the direction of the incident radiation 5. The active insulation layer 3 is preferably composed of one or more semiconductor elements. builds and has, for example, polycarbonate or silicon dioxide and each heavily depleted space charge zones.

Preferably, the active insulation layer 3 is in the form of an organic light emitting diode (OLED), wherein the organic material in the undoped state has no free charge carrier. Thus, such materials are good insulators. An organic light-emitting diode (OLED) generally consists of a substrate, an anode, an organic emitter layer and a cathode, wherein by applying a suitable electrical voltage, the degree of absorption or the degree of the generated current and thus the degree of darkening can be changed , If a voltage is applied in such a way that the current flowing in the OLED layer 3 is reduced, the degree of darkening of the layer 3 is correspondingly increased. Thus, the degree of darkening of the OLED layer 3 can be appropriately controlled by applying an appropriate voltage.

By way of example, the active insulation layer 3 is formed as OLED from suitable thin-film layers. These are already at low temperatures and thus easy and inexpensive to produce.

By way of example, the active insulation layer 3 can also be produced by means of nanotechnology or picotechnology and accordingly have nano- or pico-particles in order to improve the properties of the insulation layer 3 accordingly.

Preferably, a control device, not shown, is provided in the layer arrangement, for example a common thin-film control circuit which uses the electrical energy generated by the photovoltaic layers 1 and / or 2 to drive the active insulation layer 3 to change the degree of darkening thereof. For example, the degree of darkening of the OLED layer 3 can be achieved by applying a suitable voltage as a function of the Lenden light intensity can be controlled, in which case the incident radiation 5 is detected and evaluated. Furthermore, a control by the motor vehicle user can be made such that it manually adjusts the dimming level of the layer arrangement by setting a suitable voltage at the OLED layer 3.

In order to reduce the self-consumption and the high temperature development of the photovoltaic layers 1 and 2, it is also conceivable to form these two layers also from an organic light-emitting diode (OLED), in which case preferably the degree of absorption for generating electrical energy is high Value.

FIG. 2 illustrates a cross-sectional view of a layer arrangement applied to a transparent pane 4 according to a second preferred embodiment of the present invention. Unless otherwise stated below, the embodiments made according to the first exemplary embodiment are analogously applicable to the second exemplary embodiment.

In contrast to the first exemplary embodiment, the layer arrangement according to the second exemplary embodiment has two successive first photovoltaic layers Ia and Ib. It is obvious to a person skilled in the art that more than two first photovoltaic layers can be provided in succession. Several first photovoltaic layers cause an increase in the degree of light absorption of the entire layer arrangement and thus an increase in the generated electrical energy. Advantageously, the generated electrical energy is not used exclusively for controlling the degree of darkening of the active insulation layer, but can be stored, for example, in an energy store or used directly for operating further components of the motor vehicle. Although only a second photovoltaic layer 2 is shown in FIG. 2, it is also obvious to a person skilled in the art that two or more second photovoltaic layers 2 can also be provided in order to form the entire layer arrangement with the desired absorption and reflection properties. Furthermore, a plurality of first and second layers may also be arranged alternately or in any desired sequence.

As also shown in FIG. 2, in contrast to the first embodiment, two active insulation layers 3a and 3b are provided in succession. Again, it will be apparent to one skilled in the art that more than two active isolation layers may be provided.

The insulating layers 3a and 3b are preferably analogous to the first exemplary embodiment in each case formed as inorganic light emitting diodes (OLED) and are in each case by a common or separate control device with the energy generated by the photovoltaic layers Ia, Ib and / or 2 such energy controlled that they achieve a total desired darkening.

Although the present invention has been described above by means of preferred embodiments, it is not limited thereto, but modifiable in many ways.

LIST OF REFERENCE NUMBERS

1 first shift

Ia front first layer Ib rear first layer

2 second layer

3 active insulation layer

3a front active insulation layer

3b rear active insulation layer 4 transparent disc

5 incident light

Claims

claims

1. Layer arrangement for darkening a transparent pane (4), in particular a motor vehicle pane, for protection against incident light (5), comprising:

at least one first photovoltaic layer (1, Ia, Ib) having a high degree of light absorption;

at least one second photovoltaic layer (2) with a high degree of light absorption and a high degree of light reflection, which is arranged in the direction of the incident light (5) behind the at least one first photovoltaic layer (1, Ia, Ib);

at least one active insulating layer (3; 3a, 3b) with an electrically variable darkening degree, which is arranged in the direction of the incident light (5) behind the at least one second photovoltaic layer (2); and

a control device for electrically controlling the degree of darkening of the at least one active insulation layer (3; 3a, 3b) using the at least one first photovoltaic layer (1, Ia, Ib) and / or the at least one second photovoltaic layer (2) generated electrical energy, wherein the control device is provided in the layer arrangement as a thin-film control circuit.

2. Layer arrangement according to claim 1, characterized in that a plurality, for example two or three, first photovoltaic layers (Ia, Ib) are provided successively to increase the total amount of light absorbed.

3. Layer arrangement according to claim 1 or 2, characterized in that a plurality, for example two or three, second photovoltaic layers (2) for increasing the total absorbed and reflected amount of light are provided in succession.

4. Layer arrangement according to claim 1, characterized in that the at least one first photovoltaic layer (1, Ia, Ib) and / or the at least one second photovoltaic layer (2) each consist of at least one suitably doped semiconductor material, for example doped silicon, doped germanium or the like.

5. Layer arrangement according to claim 1, characterized in that the at least one first photovoltaic layer (1, Ia, Ib) and / or the at least one second photovoltaic layer (2) each have a nano- and / or pico material ,

6. Layer arrangement according to at least one of the preceding claims, characterized in that a plurality, for example two or three, active insulation layers (3; 3a, 3b) are provided successively to increase the overall degree of dimming.

7. Layer arrangement according to claim 1, characterized in that the at least one active insulation layer (3; 3a, 3b) is in the form of a semiconductor layer, preferably in the form of an organic light emitting diode (OLED), an LED, an LCD or a mixture of OLED, LED and LCD or the like is formed.

8. Layer arrangement according to claim 1, characterized in that the at least one active insulation layer (3; 3a, 3b) has a nano and / or pico material and / or an even smaller material.

9. Layer arrangement according to at least one of the preceding claims, characterized in that the layer arrangement on a transparent pane (4) by means of a gluing bond attachable or in a transparent pane (4) by means of a Einlamminierung, embedding, or the like can be integrated.