The invention relates to a light-transmitting screen, a building provided with such a screen and a method for screening off a room.

It is known to use a curtain, which may or may not be light-tight, for screening off a room. In order to obtain a decorative aspect upon said screening the curtain may be provided with a decoration, such as one or more pictures, which may or may not be in colour and which may or may not be accentuated by the fact that the curtain transmits light. It is also possible for the curtain to be hung or attached in folds (waved) , which may also lead to or enhance a decorative effect.

A screen may also be used for screening off certain room parts of a larger room. Furthermore it may be placed in front of the windows of a room, so that the light entering from outside is blocked entirely or partially. In both cases the screen may have a decorative function.

The object of the invention is to provide a screen which has an aesthetic value and a decorative effect, in particular in that the appearance of the screen can be varied.

In order to accomplish that objective the light- transmitting screen is according to the invention provided with at least two, at least partially transparent layers of material at least partially overlapping each other and being movable in their plane with respect to each other, whereby each of said layers of material is provided with a motif comprising a drawing or a picture, which together form a decoration, which decoration may be changed as regards colour and/or shape by moving said layers of material relative to each other in a direction which

includes an acute angle with at least part of a line in the motif of at least one of said layers of material.

When the screen is used for screening the light entering a building from outside, the windows of that building are according to the invention provided with a light- transmitting screen provided with at least two, at least partially transparent layers of material at least partially overlapping each other and being movable in their plane with respect to each other, whereby each of said layers of material is provided with a motif comprising a drawing or picture, which together form a decoration, which decoration may be changed as regards colour and/or shape by moving the layers of material relative to each other in a direction which includes an acute angle with at least part of a line in the motif of at least one of said layers of material.

The effect that can be achieved by such screening is quite surprising. A slight shift of the two layers of material relative to each other may already result in a considerable change in the appearance of the screen. By applying a different colour to each of said layers of material said colours may be mixed, in that the light entering through the screen passes both colours. As a result of that the screen may exhibit a multitude of colours, whilst only a limited number of colours has been applied to each of the layers of material.

Besides the colour effect also the figurative aspect may play an important role. A simple figurative or geometric pattern on each of the layers of material may already result in a multitude of figurative variations when said layers are slightly shifted relative to each other.

According to one feature of the invention the layers of material may be printed, they may for example be made up of a printed fabric. Furthermore the layers of material may be

provided with geometric figures or with figurative illustrations, whereby several colours may be used.

In particular, according to the invention the entire surface area or nearly the entire surface area of the two layers of material may be light-transmitting.

In order to be able to move the two layers of material relative to each other said two layers of material may according to the invention be made up of a piece of material, which is passed over a reversing roller at one end of the screen. Said reversing roller is for example located at the upper side of the screen, whereby the two layers of material hang down on either side of the roller, possibly being weighted or flexibly attached at their bottom sides. A rotation of the reversing roller will cause the two layers of material to move relative to each other, as a result of which the effect aimed at is achieved.

Furthermore, according to the invention at least one layer of material may be attached by means of resilient elements, whereby means are provided for pulling away said layer of material a little in one or more directions.

According to the invention one or more layers of material may be attached to a roller at their upper sides, by means of which roller the layer of material may be rolled up, so that the screen, or at least part thereof, can be removed.

Particularly when the screen serves to divide up a room into parts said screen may be provided with a movable frame, within which the layers of material are provided, so that the screen can be used in several places.

When the layer of material consists of a slightly elastic material it will be easier to stretch the layer of material

smoothly, whilst a desired change of the decoration may moreover be achieved by extending the layer of material.

The variation as to shape and colour may be set statically as well as be controlled dynamically. In the latter case means may be provided for moving the layers of material automatically, continuously or intermittently with respect to each other.

The method according to the invention consists of screening off a room by means of a light-transmitting screen, whereby at least two overlapping layers of material are moved relative to each other in order to give the screen the desired decorative appearance. The aforementioned features may be used with this method.

The visual effect achieved by using the invention is surprising and - also to a person skilled in the art - unexpected. Although the technique used in accordance with the invention will be clear, in particular also by the explanation given hereafter in the description of the example of an embodiment, it is practically impossible to fully illustrate the visual effects, and thus the result achieved by using the invention, by means of static black- and-white Figures.

The various layers of material may practically abut one another or be spaced apart by some distance. In the latter situation a screen which by itself is static may make a dynamic impression when being looked at at varying angles.

The invention will be explained with reference to the example of an embodiment described hereafter.

Figure 1 shows a first layer of material;

Figure 2 shows a second layer of material; and

Figures 3 - 5 show the first and second layers of material in various overlapping situations.

Figures 1 and 2 each show a portion of a layer of material provided with a print in the shape of a block pattern

(coloured squares) . The squares with left-hand hatching in Figure 1 are yellow, and the squares with right-hand hatching in Figure 2 are blue. Both layers of material are entirely transparent, so that the light entering through said layers of material is coloured by the coloured squares.

Figure 3 shows the result when the two layers of material of Figures 1 and 2 are held exactly aligned with respect to each other, creating a block pattern with green squares, which are indicated by means of a double hatching in Figure 3. The green colour is created by mixing the yellow and blue colours of the squares of Figures 1 and 2 respectively.

Figure 4 shows the result of a vertical shift of the two layers of material of Figures 1 and 2 with respect to each other. The layer of material of Figure 1 has thereby been slightly shifted downwards relative to the layer of material of Figure 2. As a result of this shifting a kind of Scottish tartan is obtained, which comprises green squares (double hatching) surrounded by a border which on the one hand is coloured blue (right-hand hatching) and which on the other hand is yellow (left-hand hatching) . Based on the two layers of material which are each provided with a one-colour print, a screen is obtained whereby the incident light produces a three-colour decoration.

Figure 5 shows the same two layers of material according to Figures 1 and 2 respectively, whereby the two layers of material have been shifted slightly more with respect to each other than in Figure 4. Said shifting results in a

block pattern comprising equally sized squares, which are alternately green (double hatching) , yellow (left-hand hatching) , blue (right-hand hatching) and colourless (no hatching) .

The embodiment illustrates the manner in which a multitude of possible variations can be obtained already with two layers of material, which are both provided with a print comprising identical, simple geometric figures, which are only different from each other as regards their colour. The number of colour mixing possibilities increases more than proportionally when more colours are used for each layer of material.

It will be apparent that there are similar possibilities when the layers of material are provided with figurative illustrations instead of with geometric figures. It is also possible thereby to vary both the line pattern and the colour.