GB2513484A

GB2513484A - Window Privacy Screen

Info

Publication number: GB2513484A
Application number: GB1407253.2A
Authority: GB
Inventors: Sara Gilmer
Original assignee: LAUREN GILMER
Current assignee: LAUREN GILMER
Priority date: 2013-04-24
Filing date: 2014-04-24
Publication date: 2014-10-29
Anticipated expiration: 2034-04-24
Also published as: GB201407253D0; EP2989277B1; WO2014174297A3; GB201612271D0; EP2989277A2; GB2513484B; WO2014174297A2

Abstract

A screen assembly includes a screen 2 for mounting outside a window 6 of a building to obscure selected outward lines of sight 10 from the window. The screen is movable with respect to the window such that further lines of sight 12, 14 are available from the window and can be changed without making available the selected obscured lines of sight. Preferably, the screen is spaced from the window and dimensions of the screen are selected so that the screen is at least as long as the hypotenuse of a right angle triangle having a base provided by the window and a height determined by the spacing from the window. In a second aspect, a kit of parts comprising a frame and a screen is provided. A building comprising a privacy screen obscuring the view between two windows and an associated method are also provided.

Description

Window Privacy Screen The present disclosure relates to methods and apparatus for screening windows, and more particularly to a privacy screen, and a method of arranging a privacy screen.

Where buildings are close together, the windows of adjacent buildings may overlook each other. In domestic dwellings this is particularly undesirable, although it is also preferable to avoid windows overlooking each other in commercial premises.

It has been proposed to use shutters or screens to preserve privacy in dwellings and to prevent people outside a building from seeing into it. It has also been proposed to arrange the windows of a building so that they do not overlook their neighbours, for example by using bay-type windows in which the central portion of the window area is screened by an opaque material.

Aspects and examples of the disclosure relate to privacy screens, and methods of arranging privacy screens as set out in the appended claims.

In one aspect the present disclosure provides a screen assembly adapted to obscure selected outward lines of sight from a window and to be movable with respect to the window so the lines of sight available from the window can be changed without making available the selected obscured lines of sight. For example, the screen assembly may be configured to obscure all lines of sight that are normal to the plane of the window. The screen may be movable by pivoting or sliding with respect to the window to enable the available lines of sight, and the amount of light incident on the window, to be varied.

One way to achieve this is to assemble a screen to a building using a mounting assembly so that the screen is arranged spaced from the window. The screen can be arranged to move with respect to the window only within a limited range of movement, and the screen can have dimensions selected so that movement of the screen within the limited range of movement changes the outward lines of sight available from the window whilst selected outward lines of sight from a window remain obscured throughout the range of movement.

Various approaches to limiting the range of movement may be used. As just one example, the screen can be operable to pivot on the frame with respect to the window to change the lines of sight available from the window. The dimensions of the screen can be selected based on the dimensions of the window and the perpendicular spacing from the window so the angular range of movement through which the screen can pivot is limited.

As one example, if the window is considered to be the base of a right angle triangle, and the hypotenuse of that triangle is provided by the screen, the angular range of movement of the screen can then be restricted by virtue of its length and its spacing from the window, and pivoting the screen cannot make lines of sight that are normal to the window available from the window.

In one aspect there is provided screen assembly comprising a screen for mounting outside a window of a building to obscure selected outward lines of sight from the window, wherein the screen comprises a plurality of louvres and wherein the louvres are configured to be movable with respect to the screen to modulate the incidence of light onto the window without making available the selected obscured lines of sight. This screen assembly may be fixed with respect to the window, or it may be movable with respect to the window. Where the screen is movable t may be configured so the lines of sight available from the window can be changed without making available the selected obscured lines of sight.

The screen assembly and/or the louvres may be configured to obscure the available lines of sight normal to the plane of the window. The assembly may be configured to space the screen from the window and the dimensions of the screen can be selected based on the dimensions of the window and the spacing between the window and the screen. For example, the dimensions of the screen can be selected so that the screen is at least as long as the hypotenuse of a right angle triangle having a base provided by the window and a height determined by the spacing of the screen from the window.

In some embodiments, the screen comprises a plurality of louvres. The louvres may have reflective surfaces arranged to reflect light towards the window. The reflective surfaces may comprise metallic, silvered, or mirrored surfaces. Rotation of the louvres may be constrained so that the louvres are operable to rotate only within a selected range of angles. As one example, the selected range of angles can be selected based on the width of the louvres to ensure that rotation of the louvres does not make available any line of sight through the screen from the window.

The screen assembly may comprise a controller configured to control the selected range of angles through which the louvres can be rotated based on the position of the screen.

This controller may be provided by an electronic controller configured to sense the angle of the screen with respect to the window, and to adhust the range of rotation of the louvres based on the angle of the screen, or it may be provided by a mechanical controller, operable to constrain movement of the louvres based on rotation of the screen. For example the controller may comprise a rotatable gear adapted to be rotated by the pivoting of the screen on the frame, wherein the gear is coupled to adjust a plurality of mechanical stops for constraining the range of movement of the louvres.

Other mechanical and/or electrical controllers may be used so that the range of angles through which the louvres can be rotated is determined by the position of the screen to ensure that the selected obscured lines of sight remain obscured (e.g. cannot be made available by rotation of the louvres).

In some embodiments the screen assembly comprises a mover configured to rotate the louvres based on sensed light conditions to modify the incidence of light towards the window. In addition, or as an alternative, the scree assembly may comprise a mover configured to move the whole screen based on sensed light conditions to modify the incidence of light towards the window. A surface of the screen may be reflective, and for example the reflective surface may comprise a metallic, silvered or mirrored surface.

Some screens may comprise a solar panel, and the solar panel may comprise at least one of photovoltaic cells, and a solar water heater.

The screen may be operable to be retracted toward the wall, and locked in place to secure the window. In some examples a recess is provided around the window, and the screen is adapted to fit into the recess.

The screen may comprise a thermally insulating fire retardant panel. For example the screen may comprise one or more fire retardant layers such as intumescent materials and/or may comprise rock wool gypsum board, asbestos cement, perlite calcium silicate, or plywood or other timber treated with fire retardant substances such as hydroxides of aluminium or magnesium.

The screen may be configured to be retracted toward the window in the event of a fire. In some embodiments the screen assembly may be coupled to a fire sensor, such as a heat sensor or smoke sensor configured to for sense a fire outside the building.

Accordingly, the screen assembly may comprise a controller configured to retract the screen toward the window in the event that the fire sensor senses a fire.

In some embodiments there is provided a kit of parts for a screen assembly, the kit comprising a frame for coupling a screen to a building outside a window to enable a screen to pivot with respect to the window, a screen for mounting to the frame. The kit may comprise least one extension panel adapted to be fixed to the screen to extend the panel. The kit may further comprise a window4rame carrying attachment points for attaching the window-frame to the frame of the screen assembly. The frame of the kit can be configured to space the screen from the window, and the length of the screen is selected based on the spacing provided by the frame and the size of the window-frame.

Some embodiments of the invention will now be described, by way of example only with reference to the accompanying drawings, in which: Figure 1 shows a schematic plan view of a screen assembly arranged outside a window; Figure 2 shows a schematic plan view of a second screen assembly arranged outside a window; Figure 3A shows a schematic plan view of a screen assembly configured to move in response to prevailing light conditions, inset in Figure 3A is a schematic diagram of the control means which moves the screen; Figure 38 shows a schematic view of a louvred screen; Figure 30 shows a section through the screen of Figure 3B along the line C-C indicated in Figure 3B; Figure 4 shows a schematic plan view illustrating one type of frame for mounting a screen to a building; Figure 5 shows a schematic plan view illustrating another type of frame for mounting a screen to a building; Figure 6 shows a schematic plan view of a screen assembly such as that illustrated in Figure 5; Figure 7 shows a schematic plan view of another screen assembly; Figure 8 shows a schematic plan view of another screen assembly; Figure 9 shows a schematic plan view of another screen assembly; and Figure 10 shows a privacy screen assembly comprising a plurality of screens each arranged to obscure the lines of sight normal to the plane of the window from a corresponding one of a plurality of adjacent portions of a window.

Figure 1 shows a plan view of a wall 8 of a building having a window 6 arranged in the wall 8. A privacy screen 2 is arranged outside the window to restrict lines of sight in to and out from the window 6.

An arm 4 couples the screen 2 to the building so that it is spaced at some perpendicular distance from the window 6. As shown in Figure 1, the arm 4 is arranged to support the screen 2 at a pivot 7 to allow the screen 2 to be rotated with respect to the window 6.

The pivot 7 is configured to enable the screen 2 to pivot about a vertical axis.

As shown in Figure 1, the screen 2 is arranged so that it can only move within a limited range of positions. In Figure 1 the movement of the screen 2 is limited by the length of the screen 7, and its spacing from the wall 8 of the building. One extreme of this range of movement is illustrated in solid lines by the screen 2, and another extreme of this range of movement is illustrated by phantom lines 2'. In Figure 1 the window 7 may be considered to be the base of a right angle triangle, and the extent of the screen is selected so that it is at least as long as the hypotenuse of the right angle triangle having the window as its base, and having a height determined by the arm 4.

In operation of, with the screen 2 in the position illustrated in Figure 1, some lines of sight 12 are available at one side of the window 6, whilst other lines of sight 10, 14 are obscured. As the screen 2 is moved through its range of movement into the position illustrated in phantom lines 2' some of the lines of sight 12 available from the window 6 will become obscured, whilst some obscured lines of sight 14 will become available from the window 6. However, because of the manner in which the screen is arranged, some selected lines of sight 12 will remain obscured.

Figure 2 illustrates another privacy screen 22, and shows a plan view of a wall 8 of a building having a window 6 arranged in the wall 8. The privacy screen 22 is arranged outside the window to restrict lines of sight in to and out from the window 6.

In Figure 2, the screen 22 is flexible, and configured to slide along a track 28 coupled outside the building by arms 24, 26. To provide flexibility, the screen of Figure 2 may for example be provided by a roller shutter comprising a plurality of scrolled slats. The track 28 is arranged in a half-stadium configuration, where each end of the track 22 curves in towards the wall 8, and the screen 22 can be moved along the track within a limited range of positions. The length of the screen 22 is selected so that part of the screen always extends along all of the straight section of the half-stadium shaped track 22.

Thereby, all lines of sight which are normal to the plane of the window 6 are always obscured by the screen 22, regardless of its movement along the track 28.

Accordingly, in operation of the screen assembly shown in Figure 2 with the screen 22 in the position illustrated by the heavy black line, some lines of sight 12 are available at one side of the window 6, whilst other lines of sight 10, 14 are obscured. As the screen 22 is moved along the track through its range of movement into the position illustrated in phantom lines 22', some of the lines of sight 12 available from the window 6 will become obscured, whilst some obscured lines of sight 14 will become available from the window 6. However, because of the manner in which the screen is arranged, some selected lines of sight 12 will always remain obscured.

Figure 1 and 2 illustrate two configurations of screens, but it is anticipated that other arrangements may be used, and some of these are illustrated in later drawings.

As will be appreciated by the skilled addressee in the context of the present disclosure, in embodiments where the screen is movable, particular configurations such as those illustrated in the drawings may be advantageous, but other configurations may also be used. For example the screen need not pivot, and where the screen is arranged to pivot it may be configured to pivot along other axes, or it may be pivoted from any point along its length, or from one end of the screen. As another example, the screen need not slide along a track, and where it does slide along a track the screen may be suspended from the track, or carried on it. The track need not be curved, and the screen of course does not need to be flexible. Where a flexible screen is used it may be provided in the manner of a roller shutter, e.g. using scrolled slats, or it may comprise a flexible material.

In Figure 1 and Figure 2 the lines of sight 10 which are permanently obscured by the screen are those which lie normal (perpendicular) to the plane of the window. However, as will be appreciated by the skilled reader in the context of the present disclosure, more or fewer selected lines of sight may be obscured, for example the lines of sight to be obscured may be selected based on the arrangement of one or more windows on an adjacent building.

Figure 3A shows a privacy screen assembly that is configured to adjust the available lines of sight from the window based on prevailing light conditions. The arrangement in Figure 3A is similar to that shown in Figure 1, and in Figure 1 and Figure 3A like reference numerals are used to indicate like elements.

As in Figure 1 a screen 2 is arranged outside a window 6 as described above, in addition, the apparatus of Figure 3A comprises a device 37 for moving the screen. A schematic diagram of components of the device 37 is shown in Inset A of Figure 3A. In Figure 3A-lnset A the device 37 comprises a mover 32 for moving the screen 2, two light sensors 34, 35, a power provider 36, and a controller 38.

The controller 38 is coupled to the power provider 36, the mover 32, the first light sensor 34, and the second light sensor 35. The controller 38 may comprise any processing means such as an application specific integrated circuit, ASIC, a FPGA, a combination of logic gates, an analogue electronic control circuit, or a suitably programmed general purpose processor comprising a signal or computer readable storage media encoding computer readable program instructions operable to program a programmable processor to control the mover 32 based on signals obtained from the sensors 34, 35 The power provider 36 is coupled to provide electrical power to the mover 32 and the controller 38. The power provider may comprise a battery, or it may be a coupling to a main power supply from the building, or it may be provided by a solar panel carried on the screen 2.

The first light sensor 34, and the second light sensor 35 are configured to provide a signal to the controller based on the level of light sensed by the sensors. The sensors 34, are arranged to collect light from different directions to enable the controller to determine, based on signals from the sensors 34, 35, the direction from which the predominant light source is incident on the window 6.

The mover 32 comprises an electric motor operable to rotate the screen 2 about its pivot 7. The controller 38 is operable to control the mover 32 to move the screen 2 about its pivot 7 based on the light sensed by the sensors 34, 35.

In operation, the controller 38 compares a signal obtained from the first light sensor 34 with a signal obtained from the second light sensor 35 to determine the direction from which most light is incident toward the window 6. Based on this comparison, the controller 38 operates the mover 32 to move the screen 2 to vary the amount of light that is incident on the window 6 and/or incident on the screen 2. This enables, for example, the screen 7 to be moved in response to the movement of the sun throughout the day to improve natural light conditions in a room. In addition, the screen assembly may be configured to reduce the amount of natural light which is able to enter through the window 6. In some embodiments the screen may comprise a solar panel, and the controller can be configured so that the screen tracks the movement of the sun to increase the amount of light that is incident on the screen.

Although in Figure 3A the device 37 is shown as an integrated unit in some embodiments the functionality of the device is distributed about the screen assembly and/or the building. For example, some or all of the components may be carried on the wall 8 of the building, or on the window 6. The sensors 34, 35 may be provided toward opposite ends of the screen 2, or on the wall 8 adjacent opposite sides of the window 6.

The light sensors 34, 35 may comprise photodiodes or photoresistors (e.g. light dependent resistors) or any other light sensor. In addition, the mover 32 may comprise any type of actuator, and may for example be an electro-mechanical actuator. The use of the device 37 has been described with reference to pivoting screens, but similar devices may be applied to move screens which move other than by pivoting such as, for example, the sliding screen of Figure 2.

Figure 38 shows an example of a screen 200 comprising a plurality of louvres 204. The louvres 204 are coupled between end pieces 202, 202' which hold the louvres in place to provide the screen 200. Each of the louvres 204 are operable to rotate to allow light and ventilation to pass through the screen. The surfaces of the louvres 204 which face in towards the window are reflective.

The endpieces 202 are coupled to pivots 370, 370 for mounting the screen 200 to a frame such as the frame 4 described with reference to Figure 1, and Figure 3A. The endpieces 202 also comprise a device similar to the device 37 described above with reference to Figure 3A, comprising light sensors for sensing prevailing light conditions, a mover for moving the louvres, and a controller configured to move the louvres based on sensed light conditions.

As shown in Figure 30, the louvres are able to rotate through a range of angles a, and each louvre has a width d. The range of angles through which the louvres can rotate is constrained based on their width, d, to ensure that no line of sight that is normal to the plane of the screen 200 is available through the screen 200.

In operation, the light sensors sense the direction from which light is falling on the screen and the controller controls the mover to move the louvres 204 so that light is -10-reflected by the reflective surfaces of the louvres and in towards the window.

It will be appreciated that the controller may also be configured to move the louvres to inhibit light from being reflected into the window from the screen. In one example the range of rotation of the louvres may not be constrained, for example the louvres may be operable to rotate through 1800, 2700, or 360°. In these and other examples, one side of the louvres may carry a relective surface whilst the other side of the louvres may comprise a less reflective surface, which may be dark, or matt, or comprise a surface configured to diffuse any reflected light. Accordingly, the louvres may be controlled to reflect light away from the window and/or to reduce the amount of light reflected from the screen and into the window.

In some examples the endpieces 202, 202, may comprise a controller configured to control the range of rotation ci of the louvres based on the angle of screen with respect to window. For example, the controller may be configured to rotate the louvres to ensure that no line of sight is available from the window through the louvres.

Any of the embodiments described herein may employ a screen such as that described with reference to Figure 3B Figure 4, Figure 5, Figure 6, Figure 7 and Figure 8 each illustrate in plan view screen assemblies similar to those described with reference to Figure 1. In these Figures like reference numerals are used to indicate like elements.

Figure 4 shows a screen 2 mounted outside a window 6 arranged in the wall 8 by a movable mounting frame 44.

With the screen 2 in the position illustrated in Figure 4, some lines of sight are available whilst other lines of sight are obscured. The screen 2 is movable on the mounting frame 44, and arranged so that it can move by pivoting with respect to the frame 44 only within a limited range of angular movement. Accordingly, as it moves through this range some of the lines of sight available from the window 6 will become obscured, whilst some obscured lines of sight will become available from the window 6. However, because of -11 -the manner in which the screen is arranged, some selected lines of sight 12 will remain obscured however the screen is moved.

The frame 44 of Figure 4 is arranged to enable the screen 2 to be retracted in toward the window 6 and the wall 8 to enable the screen to be used as a security shutter. In Figure 4 the frame 44 comprises frame members that are hinged so that the frame 44 is collapsible to retract the screen toward the window. The frame 44 may be lockable to hold the screen 2 against the window 6. In addition, or as an alternative, further locking means may be provided to secure the screen 2 closed against the window 6.

Figure 5 illustrates an example of a screen assembly in which one side of the screen 2 is fixed to the wall 8 to hold the screen in a selected position.

Figure 6 illustrates an example of a screen assembly such as that shown in Figure 1 in which the screen is arranged to make available lines of sight at both sides of the window 6.

Figure 7 illustrates another example of a screen assembly similar to that shown in Figure I wherein the screen is curved or bowed in toward the wall 8 at the ends of the screen 2.

This has the advantage of further restricting the available lines of sight available from the window. In some examples the screen may be bowed outward from the wall 8 at the ends of the screen, and this has the advantage of increasing the amount of ambient light that is reflected into the room by the screen whilst also making available more outward lines of sight from the window 6.

Figure 8 illustrates another example of a screen assembly similar to that shown in Figure I wherein the screen 2 is mounted on a single pivot arm 84. In Figure 8 the screen 2 is operable to be retracted in toward the window 6 and the wall 8 to enable the screen to be used as a security shutter. This may be accomplished by the arm 84 being telescopic, or by the screen being operable to slide along the arm 84 toward and away from the window 6.

Figure 9 illustrates another example of a screen assembly similar to that shown in Figure -12 - 1. In Figure 9 a screen 220 is mounted on a frame 4 coupled to the window 6, or the window-frame, or to the wall 8 above or below the window 6. Coupled to each end of the screen 220 are slidable extension panels 222, 224 which are operable to extend the length of the screen. By sliding the extension panels 222, 224 the length of the screen can be adjusted so that the screen assembly can be adapted for different sized windows and/or to adjust the lines of sight that are available from a window and/or those lines of sight which are permanently obscured by the screen.

Although the extension panels are shown as being slidable, extension panels need not be slidable, and for example may be clipped or otherwise fixed onto the screen to extend its width and/or length. In Figure 9 the extension panels are shown as extending the length of the screen 220. In some examples extension panels may also be provided to adjust the height of the screen.

Figure 10 illustrates an example of a screen assembly comprising a plurality of screens 2, 2', 2". As illustrated in Figure 10, each privacy screen 2, 2', 2" is arranged outside the window to restrict lines of sight in to and out from a portion of the window 6.

An arm 4, 4', 4" couples each screen 2, 2', 2" to the building so that it is spaced at some perpendicular distance from the window 6. As shown in Figure 1, the arms 4, 4', 4" are arranged to support the screen 2, 2', 2" at a pivot 7, 7', 7" to allow the corresponding screen 2, 2', 2" to be rotated with respect to the window 6. The pivot 7, 7', 7" may be configured to enable the screen 2 to pivot about a vertical axis.

As illustrated in Figure 10, the dimensions of each screen 2, 2', 2" are selected so that the screen is at least as long as the hypotenuse of a right angle triangle having a base provided by a portion of the window from which the lines of sight normal to the plane of the window are to be obscured, and a height determined by the spacing of the screen from the window (e.g. based on the length of the arm). The plurality of screens 2, 2', 2" may each be arranged to obscure the lines of sight normal to the plane of the window from a corresponding one of a plurality of adjacent portions of a window. These adjacent portions of the window may be selected to span the window. -13-

Screen assemblies may be provided in kits of parts, which may comprise the screen, the frame for the screen and one or more extension panels.

Any of the screens described herein, for example the screen described and shown in the drawings may comprise fire retardant materials. Examples of screens may comprise one or more thermally insulating fire retardant panel. For example the screen may comprise one or more fire retardant layers such as intumescent materials and/or may comprise rock wool gypsum board, asbestos cement, perlite calcium silicate, or plywood or other timber treated with fire retardant substances such as hydroxides of aluminium or magnesium.

Other possibilities include that the screen can be arraned to be adjustable in length both vertically or horizontally through the addition of filler pieces (such as extension panels).

In one possibility the screen can be fitted with a solar panel with additions, such as the controller described with reference to Figure 3A allowing for the rotation of the panel throughout the day to allow for maximum solar gain.

In one possibility the screen can be constructed using fire insulated material and configured to close in the event of a fire at a neighbouring building.

The screens described herein can be finished with any material such as brick, aluminium, timber or glass, etc. In one possibility the screen is louvred, the louvres may be arranged horizontally and/or vertically, and may comprise a fine louvred mesh with the louvers orientated to allow maximum light in toward the window but to prevent overlooking. -14-

In one possibility the screen may comprise a reflective material on the internal surface of the screen to force maximum light and subsequent solar heat gain in through the window.

In one possibility, the screen can comprise advertiseing media. In one possibility the screen can comprise an antenna, such as a satellite receiving device, for example a satellite dish for receiving television signals.

In one possibility the screen comprises a locking mechanism configured to lock the screen to the building.

In one possibility the frame for supporting the screen can be incorporated into the window-frame or alternatively a window frame may be provided comprising clips for fitting the frame of the screen assembly to the window frame.

As will be appreciated by the skilled reader in the context of the present disclosure the screen assemblies disclosed herein may be retrofitted to pre-existing buildings to improve the privacy of the rooms of the building and those of adjacent buildings.

Embodiments of the disclosure comprise buildings, and pairs of buildings having privacy screens substantially as disclosed herein with reference to Figures 1 to 8 arranged to obscure the windows of one building from view from the other. Other implementations, examples and variations of the present disclosure may be provided, and it is anticipated that the features of any of the screen assemblies described herein may be combined with one or more other features of any of the other screen assemblies, or combinations thereof. -15-

Claims

Claims: 1. A screen assembly comprising a screen for mounting outside a window of a building to obscure selected outward lines of sight from the window, wherein the assembly is adapted so that the screen is movable with respect to the window such that the lines of sight available from the window can be changed without making available the selected obscured lines of sight.
2. The screen assembly of claim 1 comprising a frame for coupling the screen to the building, wherein the screen and frame are arranged so that the screen is operable to pivot with respect to the window to change the lines of sight available from the window, and the movement of the screen is limited so that the selected obscured lines of sight cannot be made available by pivoting the screen.
3. The screen assembly of any preceding claim wherein the screen assembly is configured to obscure the available lines of sight normal to the plane of the window.
4. The screen assembly of any preceding claim wherein the assembly is configured to space the screen from the window and the dimensions of the screen are selected based on the dimensions of the window and the spacing between the window and the screen.
5. The screen assembly of claim 4 in which the dimensions of the screen are selected so that the screen is at least as long as the hypotenuse of a right angle triangle having a base provided by the window and a height determined by the spacing of the screen from the window.
6. The screen assembly of claim I in which the screen comprises a plurality of louvres having reflective surfaces, wherein the louvres are operable to be rotated so that the reflected surfaces are arranged to reflect light towards the window.
7. The screen assembly of claim 6 in which the reflective surfaces are silvered or mirrored. -16-
8. The screen assembly of any preceding claim in which the screen comprises a plurality of louvres and rotation of the louvres is constrained so that the louvres are operable to rotate only within a selected range of angles.
9. The screen assembly of claim 8 in which the selected range of angles is selected based on the width of the louvres to ensure that rotation of the louvres does not make available any line of sight through the screen from the window.
10. The screen assembly of claim 9 in which the selected range of angles through which the louvres can be rotated is selected based on the position of the screen.
11. The screen assembly of claim 9 or 10 comprising a controller configured to control the selected range of angles through which the louvres can be rotated based on the position of the screen.
12. The screen assembly of any of claims 6 to 11 further comprising a mover configured to rotate the louvres based on sensed light conditions to modify the incidence of light towards the window.
13. The screen assembly of any preceding claim comprising a mover configured to move the screen based on sensed light conditions to control the incidence of light on the window.
14. The screen assembly of any preceding claim comprising a solar panel carried on the screen.
15. The screen assembly of claim 14 wherein the solar panel comprises at least one of photovoltaic cells, and a solar water heating apparatus.
16. The screen assembly of any preceding claim in which the screen is operable to be retracted toward the wall, and locked in place to secure the window.
17. The screen assembly of any preceding claim, wherein the screen comprises a -17-thermally insulating fire retardant panel.
18. The screen assembly of claim 17, wherein the screen is configured to be retracted toward the window in the event of a fire.
19. The screen assembly of claim 18 comprising a fire sensor for sensing a fire outside the building, and a controller configured to retract the screen toward the window in the event that the fire sensor senses a fire.
20. The screen assembly of claim 1 comprising a frame for coupling the screen to the building, wherein the screen and frame are arranged so that the screen is operable to translate laterally with respect to the window to change the lines of sight available from the window, and the movement of the screen is limited so that the selected obscured lines of sight cannot be made available by lateral translation of the screen.
21. The screen assembly of claim 20 wherein the screen assembly is configured to obscure the available lines of sight normal to the plane of the window.
22. The screen assembly of claims 20 or 21 having the features of any of claims 2 to 19.
23. The screen assembly of claim 4, or any of claims 5 to 22 as dependent upon claim 4, comprising a plurality of screens in which the dimensions of each screen are selected so that the screen is at least as long as the hypotenuse of a right angle triangle having a base provided by a portion of the window from which the lines of sight normal to the plane of the window are to be obscured, and a height determined by the spacing of the screen from the window.
24. The screen assembly of claim 23 in which the plurality of screens are each arranged to obscure the lines of sight normal to the plane of the window from a corresponding one of a plurality of adjacent portions of a window.
25. The screen assembly of claim 24 in which the plurality of adjacent portions of the -18-window are selected to span the window.
26. A kit of parts for a screen assembly according to any preceding claim, the kit comprising a frame for coupling a screen to a building outside a window to enable a screen to pivot with respect to the window, a screen for mounting to the frame.
27. The kit of parts of claim 26 further comprising least one extension panel adapted to be fixed to the screen to extend the panel.
28. The kit of parts of claims 26 or claim 27 further comprising a window-frame carrying attachment points for attaching the window-frame to the frame of the screen assembly.
29. The kit of parts of claim 28 wherein the frame is configured to space the screen from the window, and the length of the screen is selected based on the spacing provided by the frame, and the size of the window-frame.
30. A building comprising: a wall comprising a first window, wherein the wall is arranged to face a second wall comprising a second window, and a privacy screen coupled to the exterior of the building and arranged relative to the window such that the second window is obscured from view from the first window by the privacy screen.
31. The building of claim 30 wherein the dimensions of the privacy screen are selected based on the size of the second window in the second wall and the spacing between the screen and the first wall.
32. The building of claim 30 or 31 wherein the second wall is a wall of a different building.
33. The building of any of claims 30 to 32 in which the screen is movable with respect to the first window such that the lines of sight available from the window can be changed -19-without making available a line of sight from the first window to the second window.
34. The building of any of claims 30 to 33 comprising the screen assemblies of any of claims I to 25, or the kit of parts of any of claims 26 to 29.
35. A method of adapting a building comprising a wall comprising a first window, wherein the wall is arranged to face a second wall comprising a second window, the method comprising securing a privacy screen to the exterior of the building relative to the first window such that the second window is obscured from view from the first window by the privacy screen.
36. The method of claim 35 in which securing the screen to the building comprises providing a spacing between the screen and the first window to enable light to enter the building through the window, the method further comprising selecting the spacing based on the dimensions of the screen and the dimensions of the second window.
37. The method of claim 35 or 36 wherein the screen is provided by the screen assembly of any of claims 1 to 25, or the kit of parts of any of claims 26 to 29.
38. A privacy screen assembly substantially as described herein with reference to the accompanying drawings.
39. A building comprising a privacy screen assembly according to any of claims I to 25, or a screen assembly assembled from the kit of parts of claims 26 to 29, or the screen assembly of claim 38.Amendments to the claims have been made as follows: Claims: 1. A screen assembly comprising a screen for mounting outside a window of a building to obscure selected outward lines of sight from the window, wherein the assembly is configured to space the screen from the window and the dimensions of the screen are selected so that the screen is at least as long as the hypotenuse of a right angle triangle having a base provided by the window and a height determined by the spacing of the screen from the window; and the assembly is adapted so that the screen is movable with respect to the window such that the lines of sight available from the window can be changed without making available the selected obscured lines of sight.2. The screen assembly of claim I comprising a frame for coupling the screen to the building, wherein the screen and frame are arranged so that the screen is operable to v" 15 pivot with respect to the window to change the lines of sight available from the window, tiC) and the movement of the screen is limited so that the selected obscured lines of sight cannot be made available by pivoting the screen.C3. The screen assembly of any preceding claim wherein the screen assembly is configured to obscure the available lines of sight normal to the plane of the window.4. The screen assembly of claim 1 in which the screen comprises a plurality of louvres having reflective surfaces, wherein the louvres are operable to be rotated so that the reflected surfaces are arranged to reflect light towards the window.5. The screen assembly of claim 4 in which the reflective surfaces are silvered or mirrored.6. The screen assembly of any preceding claim in which the screen comprises a plurality of louvres and rotation of the louvres is constrained so that the louvres are operable to rotate only within a selected range of angles.7. The screen assembly of claim 6 in which the selected range of angles is selected based on the width of the louvres to ensure that rotation of the louvres does not make available any line of sight through the screen from the window.8. The screen assembly of claim 7 in which the selected range of angles through which the louvres can be rotated is selected based on the position of the screen.9. The screen assembly of claim 7 or 8 comprising a controller configured to control the selected range of angles through which the louvres can be rotated based on the position of the screen.10. The screen assembly of any of claims 4 to 9 further comprising a mover configured to rotate the louvres based on sensed light conditions to modify the incidence of light towards the window."" 15 11. The screen assembly of any preceding claim comprising a mover configured to tiC) move the screen based on sensed light conditions to control the incidence of light on the 0 window.12. The screen assembly of any preceding claim comprising a solar panel carried on the screen.13. The screen assembly of claim 12 wherein the solar panel comprises at least one of photovoltaic cells, and a solar water heating apparatus.14. The screen assembly of any preceding claim in which the screen is operable to be retracted toward the wall, and locked in place to secure the window.15. The screen assembly of any preceding claim, wherein the screen comprises a thermally insulating fire retardant panel.16. The screen assembly of claim 15, wherein the screen is configured to be retracted toward the window in the event of a fire.17. The screen assembly of claim 16 comprising a fire sensor for sensing a fire outside the building, and a controller configured to retract the screen toward the window in the event that the fire sensor senses a fire.18. The screen assembly of claim I comprising a frame for coupling the screen to the building, wherein the screen and frame are arranged so that the screen is operable to translate laterally with respect to the window to change the lines of sight available from the window, and the movement of the screen is limited so that the selected obscured lines of sight cannot be made available by lateral translation of the screen.19. The screen assembly of claim 18 wherein the screen assembly is configured to obscure the available lines of sight normal to the plane of the window.20. The screen assembly of claims 20 or 21 having the features of any of claims 2 to 15 19. LtD21. The screen assembly of any preceding claim comprising a plurality of screens in C which the dimensions of each screen are selected so that the screen is at least as long as the hypotenuse of a right angle triangle having a base provided by a portion of the window from which the lines of sight normal to the plane of the window are to be obscured, and a height determined by the spacing of the screen from the window.22. The screen assembly of claim 21 in which the plurality of screens are each arranged to obscure the lines of sight normal to the plane of the window from a corresponding one of a plurality of adjacent portions of a window.23. The screen assembly of claim 22 in which the plurality of adjacent portions of the window are selected to span the window.24. A kit of parts adapted to provide a screen assembly according to any preceding claim, the kit comprising a frame for coupling a screen to a building outside a window to enable a screen to pivot with respect to the window, and a screen for mounting to the frame.25. The kit of pads of claim 24 further comprising least one extension panel adapted to be fixed to the screen to extend the panel.26. The kit of parts of claims 24 or claim 25 further comprising a window-frame carrying attachment points for attaching the window-frame to the frame of the screen assembly.27. The kit of parts of claim 26 wherein the frame is configured to space the screen from the window, and the length of the screen is selected based on the spacing provided by the frame, and the size of the window-frame.28. A building comprising: a wall comprising a first window, wherein the wall is arranged to face a second "" 15 wall comprising a second window, and tiC) a privacy screen coupled to the exterior of the building and arranged relative to the window such that the second window is obscured from view from the first window by C the privacy screen; wherein the privacy screen is mounted to be movable with respect to the first window so the lines of sight available from the first window can be changed, and the mounting is configured such that the range of movement of the screen is restricted to prevent movement of the screen from making available a line of sight from the first window to the second window.29. The building of claim 28 wherein the dimensions of the privacy screen are selected based on the size of the second window in the second wall and the spacing between the screen and the first wall.30. The building of claim 28 or 29 wherein the second wall is a wall of a different building.31. The building of any of claims 28 to 30 in which the screen is movable with respect to the first window such that the lines of sight available from the window can be changed without making available a line of sight from the first window to the second window.32. The building of any of claims 28 to 31 comprising the screen assemblies of any of claims I to 23, or the kit of parts of any of claims 24 to 27.33. A method of adapting a building comprising a wall comprising a first window, wherein the wall is arranged to face a second wall comprising a second window, the method comprising securing a privacy screen to the exterior of the building relative to the first window such that the second window is obscured from view from the first window by the privacy screen.34. The method of claim 33 in which securing the screen to the building comprises providing a spacing between the screen and the first window to enable light to enter the building through the window, the method further comprising selecting the spacing based " 15 on the dimensions of the screen and the dimensions of the second window. LtD35. The method of claim 33 or 34 wherein the screen is provided by the screen C assembly of any of claims 1 to 25, or the kit of parts of any of claims 26 to 29.36. A privacy screen assembly substantially as described herein with reference to the accompanying drawings.37. A building comprising a privacy screen assembly according to any of claims I to 23, or a screen assembly assembled from the kit of parts of claims 24 to 27, or the screen assembly of claim 36.