DE102013020874A1 - Sun visor on a transparent pane, in particular on a windshield of a motor vehicle, in particular a commercial vehicle - Google Patents

Abstract

The invention relates to a sun visor (1) on a transparent pane (5), in particular on a windshield (16) of a motor vehicle, in particular a utility vehicle (15). The sun visor (1) according to the invention comprises an electro-optically switchable liquid crystal film (LC film 3) and at least one associated solar cell (2) with which a switching voltage level can be generated when exposed to sunlight.

Description

The invention relates to a sun visor on a transparent pane, in particular on a windshield of a motor vehicle, in particular a utility vehicle according to the preamble of claim 1.

Sunshades on motor vehicles are known in a variety of different embodiments: In passenger cars are usually in the vehicle interior above a front windshield plate-shaped, opaque sun protection panels arranged, which are folded down as needed down in the field of view of a vehicle occupant to block the sun.

In trucks sun visors are well known, which are mounted in the upper part of the cab in front of the windshield. Such made of plastic sun visor panels are prone to embrittlement, stone chipping and other mechanical effects such as hail. In addition, such sun visors in the production and possibly as a retrofit part incl. Installation are relatively expensive.

Further, the electro-optical effect in liquid crystals has long been known, with which they are transparent under an associated specific switching voltage level, that is, viewing and image permeable and when exposed to the switching voltage level and higher levels in an opaque, that is opaque state are switchable. By "opaque" is meant here also a translucent state, with a significantly reduced light transmission compared to the transparent state. When applying a certain voltage thus reduces the light transmittance in liquid crystals in particular by influencing the polarization of the light. This effect is used for example in many displays.

Furthermore, it is already known to switch windows on buildings from transparent to opaque with the aid of liquid crystal technology.

Object of the invention is to form conventional sun visors depending on their design, especially in commercial vehicles, less susceptible to mechanical influences and also to facilitate handling by an automated sun visor function. In addition, a space-saving attachment should be possible with relatively low production and assembly costs.

This object is achieved with the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

According to the invention, a sun visor is formed by an electro-optically switchable liquid crystal film (LC film) and at least one associated solar cell with which a switching voltage level can be generated when exposed to sunlight.

This results in an electrically self-sufficient system, which manages without additional external voltage and automatically switches the sun visor function upon reaching the switching voltage level, corresponding to a sufficient solar radiation to the at least one solar cell. The LC foil has a transparent state below the assigned switching voltage level and, from the switching voltage level, an opaque state as a sun visor function.

For this purpose, the LC film is attached to the pane in the size of the area to be shaded, preferably indirectly attached to the inside of the pane. When used in a motor vehicle, especially in a commercial vehicle, this is an upper edge strip on the inside of the windshield.

Optionally, a plurality of solar cells for supplying power to the LC film or for generating the switching voltage level are required and provided, which are arranged facing in the direction of solar irradiation. Thus, depending on the specific configuration of the LC film, electrical energy can be generated in the event of solar radiation, so that the switching voltage level is reached at a prescribable brightness or sunlight irradiation on the solar cells and the LC film switches from its transparent state into its opaque state which fulfills the sunblind function. In the absence or insufficient sunlight or light irradiation, the LC film is traceable back to its transparent state due to lack of sufficient supply voltage. An operation, such as folding and folding back a shutter, is not required here.

For a specific embodiment of the LC film, this consists of a front and a rear plastic film, in each case as a transparent film with on the sides facing electrically conductive and transparent coatings as electrodes, between which liquid crystals are introduced, and the liquid crystal region on all sides bounding edge strips.

In a further advantageous concretization, a transparent carrier foil is provided as system carrier, on the back side of which the LC foil and In addition, the solar cells are preferably attached as a solar cell ribbon above the LC film at the top, preferably glued. The carrier film with the LC film and the solar cells and their electrical connection and circuit components thus form a pre-producible sun protection system unit, which is flexible and attached to the front of the carrier film to the disc, preferably can be glued.

The solar cells are expediently arranged in a suitable number for sufficient power generation number as a closed solar cell ribbon in the upper region of the carrier film and thus outside the immediate field of view. In the case of a transverse extension of the sunshade panel according to the invention over the entire windshield region, an arrangement of the solar cell tape in an upper midfield region of the carrier foil is particularly suitable.

Optionally, the edge strip between the front and rear transparent film may be made opaque and thus visibly limit the shaded area of the LC film.

To protect against damage, it is advantageous to seal the prefabricated sunscreen system unit on its side opposite the carrier film side by a transparent protective film.

For the function of the sunshade also customary electrical connections and switching and control devices are to be provided for coupling the solar cells to the LC film. These may also include a switch located in the power supply circuit, with the function of the sun visor, for example, by a driver of a vehicle arbitrarily off and on. In addition, if necessary, energy surplus generated by the solar cells can be supplied to other electrical consumers and / or to store energy.

Depending on the specific circumstances, a direct control of the LC film may not be possible in all voltage states. In particular, in such a case or as a precaution generally, an electronic circuit may be provided for a suitable control of the switching levels between the solar cells and the LC foil.

Reference to a drawing, the invention will be further explained.

Show it:

1 , A plan view of a sun visor with a running over the entire transverse extent solar cell ribbon;

2 a plan view of a sun visor with a closed solar cell ribbon in the middle region;

3 a sun visor accordingly 1 with an additional display;

4 a cross section through an upper portion of a sunshade attached to a windshield,

5 a cross section accordingly 4 with an additional protective film, and

6 a truck with a sun visor accordingly 1 ,

In 1 is a top view of a sun visor 1 represented, for example, in the mounted state over the entire width in the upper region of a windshield of a motor vehicle, in particular a commercial vehicle extends.

The sun visor 1 consists of solar cells 2 and an LC film 3 , where the solar cells 2 as a closed solar cell ribbon above the LC film 3 are arranged throughout over the entire width.

In a over the entire width of the windshield extending sun visor 1 is it appropriate 2 advantageous, the solar cells 2 as a solar cell strip with a shorter length in the upper middle area above the LC film 3 to arrange. In this arrangement, the field of vision for a driver and passenger through the opaque solar cells can be seen 2 less than at 1 limited.

The LC film 3 can according to 3 at a suitable place, here at its lower edge, with a display 4 be equipped, which can take over the display of operating conditions or notes also warnings.

In 4 is a section AA through an upper area of an already on a windshield 5 glued sunshade 1 shown.

As a system carrier is a transparent carrier film 6 provided on the back of the LC film 3 and the (schematically shown) solar cells 2 , or the solar cell tape above the LC film 3 attached to the upper edge region, preferably glued.

The LC film 3 consists of a front and rear plastic film each as a transparency 7 . 11 with on the sides facing electrically conductive and transparent coatings as electrodes 8th . 10 , between which liquid crystals are introduced. The liquid crystal area is also on all sides between the transparencies 7 . 11 by edge stripes 12 limited.

5 corresponds to the arrangement according to 4 , in which case in addition to the carrier film 6 opposite inside of the LC film 3 and the solar cells 2 a transparent protective film 13 is appropriate.

The arrangement has the following function: In the dark or insufficient light or sunlight 14 in the solar cells is the LC film 3 switched transparent. Upon reaching a certain light or sunlight 14 , which can create a dazzling effect, is in the solar cells 2 generates a solar power with a voltage level as the switching voltage level, such that the LC film 3 is switched into its opaque state by the system-generated solar power and fulfills its sun visor function in this switching state. Electrical energy surplus generated by the solar cells can be used to feed other consumers or to charge a battery. As soon as the sun's rays 14 at the solar cells 2 decreases and thereby the switching voltage level is exceeded, the LC film switches back to its transparent state. The system thus controls autonomously depending on the intensity of the sun or light radiation. In addition, an actuatable switch can be mounted in the supply circuit, with which the sun visor function can be switched on and off arbitrarily, for example by a driver of a commercial vehicle.

In 6 is a truck in a perspective front view of an example 15 shown as a commercial vehicle, on the front windshield 16 in a top edge area from inside a sun visor 1 according to the embodiment according to 1 is appropriate.

LIST OF REFERENCE NUMBERS

1

Sunscreen roofs

2

Solar cells as a solar cell ribbon

3

Liquid crystal film, LC film

4

display

5

Disc, windshield

6

support film

7

front transparency

8th

Electrode on 7

9

liquid Crystals

10

Electrode on 11

11

rear transparency

12

edge strips

13

protector

14

sunlight

15

Lorry

16

Windshield

Claims (12)

Sun visor ( 1 ) on a transparent pane ( 5 ), in particular on a windshield ( 16 ) of a motor vehicle, in particular a commercial vehicle ( 15 ), characterized by - an electro-optically switchable liquid crystal film (LC film 3 ), and - at least one associated solar cell ( 2 ), with which a switching voltage level can be generated when exposed to sunlight. Sun visor according to claim 1, characterized in that the sun visor ( 1 ) by an electrically self-sufficient system consisting of the LC film ( 3 ) and the at least one solar cell ( 2 ) and that the LC film ( 3 ) in the size of the area to be shaded on the disc ( 5 ), in particular on an upper edge strip of a windshield, is mounted, wherein the LC film ( 3 ) has a transparent state below an assigned switching voltage level and an opaque state as a sunshade function from the switching voltage level. Sun visor according to claim 1 or 2, characterized in that the sun visor ( 1 ) indirectly inside the disc ( 5 ) is attached. Sun shade according to one of the preceding claims, characterized in that a plurality of solar cells ( 2 ) for the power supply of the LC film ( 3 ) and / or are provided for generating the switching voltage level, which are arranged pointing in the direction of solar irradiation, whereby at solar irradiation electrical energy can be generated, so that upon reaching the switching voltage level, the LC film ( 3 ) is switchable from its transparent state to its opaque state satisfying the sunblind function, and the LC film 3 in the event of missing or no longer sufficient sunlight or light radiation due to lack of sufficient supply voltage in its transparent state traceable. Sun visor according to one of the preceding claims, characterized in that the LC film ( 3 ) a front and rear plastic film, each as a transparency ( 7 . 11 ) with mounted on the sides facing each other electrically conductive and transparent coatings (electrodes 8th . 10 ) between which liquid crystals ( 9 ) are arranged, and a the liquid crystal region on all sides bounding marginal strips ( 12 ) having. Sunscreen according to one of the preceding claims, characterized in that as a system carrier a transparent carrier film ( 6 ), on the back of which the LC film ( 3 ) and also the solar cells ( 2 ), preferably as a solar cell strip, above the LC film ( 3 ) are attached to the upper edge region, preferably glued, are, and that the carrier film ( 6 ) with the LC film ( 1 ), the solar cells ( 2 ) and their electrical connection and circuit components between them forms a pre-fabricated sunshade system unit which is connected to the front of the carrier film ( 6 ) on the disc ( 5 ) is fastened, preferably anklebbar is. Sun shade according to claim 6, characterized in that the solar cell ( 2 ) in a sufficient number for sufficient power generation as a closed solar cell ribbon in the upper Mittelbreich the carrier film ( 6 ) is arranged. Sun visor according to claim 6 or 7, characterized in that the edge strip ( 12 ) between the front and rear transparencies ( 7 . 11 ) is opaque and thus visible the shaded area of the LC film ( 3 ) limited. Sun visor according to one of claims 6 to 8, characterized in that the prefabricated sunscreen system unit on its the carrier film ( 6 ) opposite side by a transparent protective film ( 13 ) is sealed. Sun visor according to one of the preceding claims, characterized in that electrical connections and / or switching and control devices are provided, with which the function of the sun visor ( 1 ) arbitrarily switched off and on and / or by the solar cells ( 2 ) excessively generated energy can be supplied to other electrical consumers and / or energy stores. Sun shade according to one of the preceding claims, characterized in that an electronic circuit for controlling the switching levels between the solar cells ( 2 ) and the LC film ( 3 ) is provided. Vehicle, in particular commercial vehicle ( 15 ), with a sun visor ( 1 ) according to any one of the preceding claims.

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