WO1992004522A1

WO1992004522A1 - Light transmitting arrangement

Info

Publication number: WO1992004522A1
Application number: PCT/GB1991/001483
Authority: WO
Inventors: David Watkins
Original assignee: Good Thinking Limited
Priority date: 1990-09-07
Filing date: 1991-09-02
Publication date: 1992-03-19
Also published as: AU8532391A; GB9019617D0

Abstract

The arrangement comprises a window (2), e.g. of a building, provided with adjustment means, such as a liquid crystal arrangemnt (9), for adjusting the opacity of the window. Control means (10), e.g. a microprocessor, are provided for controlling operation of the adjustment means in dependence upon a signal from input means. A wide range of input means may be used including: touch sensitive means, a tilt sensor, light level sensors provided on opposite sides of the window, means for sensing a person or vehicle, a temperature sensor, a microphone for voice actuated control and manual controls. The arrangement may also be in the form of a pair of glasses or form the windscreen or other windows of a vehicle.

Description

LIGHT TRANSMITTING ARRANGEMENT

TECHNICAL FIELD

This invention relates to a light transmitting arrangement. One embodiment of the invention comprises a window incorporated in a building or other permanent structure. Other embodiments of the invention may comprise windows in other arrangements, e.g. in a motor vehicle or in a pair of sunglasses.

BACKGROUND ART

Windows are usually associated with curtains or blinds to be used when it is desired to provide a degree of privacy within a room provided with the window, or when it is desired to prevent bright sunshine from shining into people's eyes or damaging furniture or other items within the room provided with the winαow. Such curtains or blinds may, in certain circumstances, be subjected to vandalism. Also, the degree of control over the opening and closing of such curtains or blinds is very restricted.

Windows incorporating liquid crystal devices for adjusting their opacity are also known. However, these tend to be controlled simply by means of a manual control or a single light sensor.

DISCLOSURE OF INVENTION

The present invention seeks to provide an improved light transmitting arrangement which provides for a greater range of transparency adjustments and more sophisticated control of the adjustment than known arrangements.

According to this invention there is provided a light transmitting arrangement comprising a window provided with adjustment means for adjusting the opacity of the window and control means for controlling operation of the adjustment means, the control means being arranged to operate in dependence a signal from input means, other than just the output of a manual control or the output of a single lignt sensor. Preferred features of the invention will be apparent from the following description and from the subsidiary claims of the specification.

BRIEF DESCRIPTION OF DRAWINGS

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be further described, merely by way of example, with reference to the accompany drawings in which:

Figure 1 is a schematic cross-sectional view of a wall of a building provided with a window in accordance with an embodiment of the invention and associated equipment;

Figure 2 is a plan view illustrating a wall and a window and items of furniture to be protected from the sun;

Figure 3 is a side elevational view of the wall and window and items of furniture of Figure 2;

Figure 4 is a diagrammatic view indicating how darkened areas on the window of Figures 2 and 3 may move to protect the items of furniture;

Figure 5 is a software flow chart for creating a window mask;

Figure 6 is a series of views illustrating the formation of a window mask in accordance with the software of Figure 5;

Figure 7 is a diagrammatic perspective view of a pair of sunglasses incorporating the invention; and

Figures 8A to 8F illustrate how the transparency ot the sunglasses may be varied.

BEST MODE OF CARRYING OUT INVENTION

Referring to Figure 1, a wall 1 of a building is provided with an aperture

2 in which is mounted a wooden frame 3. Mounted within the wooden frame 3 is a window 4. The window consists of two spaced parallel sheets of glass or other transparent material 5, 6. Mounted on the interior surface of the outer sheet of glass 6 is a uniform electrode 7 of transparent material sucn as tin oxide as sold under the Registered Trade Mark NESA. Provided on the interior of the interior sheet of glass 5 is a plurality oi discrete areas 8 forming transparent electrodes, again formed of tin oxide as sold under the Registered Trade Mark NESA. Individual connections are provided for each electrode 8, and each electrode 8 can be considered to correspond to a pixel. The space between the two sheets of glass is filled with a nematic liquid crystal material 9.

It will thus be understood that the window 4 effectively comprises a large liquid crystal display, with the electrodes 8 forming discrete pixels.

It is to be appreciated, however, that the electrodes may take other forms, to provide the desired effect.

Associated with the window 4, as described, are various control arrangements incluαing, in the described embodiment, a main control unit 10 mounted on the interior of the wall 1, which includes a micro-processor or the like adapted to apply potential to selected electrodes 8. It is to oe appreciated that control buttons or knobs may be mounted on the main control unit 10.

A remote hand-operated control unit il having push-button controls or the like may also be provided which is able to transmit signals to the main control unit 10 by an infra-red linn or the like. A microphone may also be provided on either of the control units 10 or 11 for voice activated control of the window.

Mounted on the interior of the wall 1 is a sensor unit 12. The sensor may be adapted to sense ambient light and/or may be able to detect movement within the room. The sensor 12 may also be adapted to detect temperature. A further sensor 13 is provided on the exterior of the wall 1. This sensor 13 may again be adapted to sense the level of ambient light, and/or may detect movement to sense personnel.

It is to be appreciated that the sensors 12, 13 are connected to the central control unit 10 and the central control unit 10 is adapted to control the window 4 by applying an appropriate control potential to selected electrodes 8, thus causing the liquid crystal in the region of those selected electrodes to become opaque.

It is to be appreciated that in use of the window, in an initial condition the liquid crystal material will not be activated by an applied potential, and thus the window will be transparent. Subsequently, a potential may be applied to some or all of the electrodes 8, thus causing the liouid crystal material, in the region of those electrodes, to become opaque. Thus, the effective transparency of the window may be reduced. By adjusting the control potential applied to the electrodes 8, and by selecting which electrodes receive the signal, the effective transparency of the window may be modulated between a totally transparent state and totally opaoue state. Alternatively, the liquid crystal material may be such that it reacts proportionately to the applied voltage to control the opacity of the window. The condition of the window may be altered at a hign frequency, beyond the registering ability of the human eye.

A safety device 14 may be provided in order to enable the window to perform satisfactorily in the event of a main power supply failure. Thus the device 14 may either contain batteries to maintain battery operation of the window or may comprise a mechanism to release a separate blind or similar mechanical screen in the event of a power failure.

The condition of the window may be controlled by actuating knobs or buttons on the central control unit 10, by operating the buttons on the remote control unit 11 or by voice actuation using the microphone. Thus, at will, the window may be made to be transparent or may be made to be opaque. However, it is envisaged that the window may have other mooes of operation. For example, the window may be caused to become progressively opaque automatically as a result of a comparison between internal ano external ambient light levels. When the level of ambient light within the room is high relative to the level of ambient light outside the room, the window may be made opaque to prevent people outside the room seeing into the room.

Alternatively, one or more areas of the window, or all of the window, may be made to become opaque by speaking command words into the microphone on the control unit 10 or control unit 1 1. For example, using the words "DOWN", "UP", and "STOP", the position control of a vertical blind may be imitated. A larger vocabulary of commands would allow for more sophisticated control of the window opacity.

Alternatively, the control mechanism may incorporate a timer allowing selected daily periods for opacity of the window between sunset and sunrise.

Alternatively, one or more sections of the window, or all of the windows, may be made to become opaque when a person is sensed within the room, for modesty purposes or when a person or vehicle is sensed outside tne window, for security reasons. The window may again be caused to become increasingly opaque in response to a sensed temperature.

Touch sensitive means may be provided to sense the position of a f inger placed upon the interior of the window. For example, the ef fect ive capacitance of each of the electrodes 8 may be monitored, by tne microprocessor of the control unit 10, this capacitance altering when a finger is applied to the window adjacent the electrodes. In response to a finger being placed on the window, when the window is opaque, the area where the f inger is placed may become transparent for a predetermined period of time. Thus, when the window is opaque, for example at night-time, by merely rubbing a finger on the interior of the window, the area where the finger is rubbed will become transparent, thus providing a "peep-hole". The "peephole" will only last for a predetermined period of time. In another arrangement, the position of the finger can be sensed to cause the window to become opaque only above the level of the finger, thus imitating a vertical blind. Other modes could be incorporated to control the opacity in other directions relative to the position of the finger.

A sopnisticated control system may be provided enapling a specific area of the window to be made opaque, so that the opaque area of the window casts a shadow into the room. The area of the window made to be opaque may be selected so that the shadow fails on a particular item of furniture that is not to be damaged by ultra-violet radiation from the sun. The microprocessor may be programmed so that, as time passes, the position of the area of the window that is opaque moves in accordance with the movement of the sun, relative to the window, so that the item of furniture remains in shadow at all times. The mask may only be active according to the sensed exterior brighthess so that during cloudy periods the mask would not be seen.

To achieve this object the micro-processor may utilise information relating to the time, date, and position and orientation of the window, together with information relating to the effective track of the sun, or the sensor 13 may include a light-sensitive imaging device, such as a charge coupled device which monitors the position of the sun relative to the window, and provides that information to the controller which can then calculate which area of the window should be made to be opaque to provide the desired effect.

Simpler control software could be used if three or more mask positions are defined which actually cause a shadow to be cast on the object at different times. The software could then move a mask so that it occupies the defined positions at the appropriate times. This would be appropriate for certain specific applications - for example, where sunlight is reflected from adjacent buildings. The algorithm generated from the three or more positions of the mask, to control the movement of the mask, may also be used to control the movement of other masks, so that they will provide shade for other objects. This algorithm is easily calculated as it is based on the and of a circle, and also the seasonal changes of the sun's position are easily calculated as they are based on a sine wave with the highest point being midsummer and the lowest point being midwinter. In cases where the window is movable, allowance needs to be made for the 'stretching' or 'shrinking' of the mask shape, and this is calculated by knowing the angular change in position of the window (measured by a tilt or position sensor), and the distance of the mask from the window hinge axis (which is always known).

Figures 2 and 3 illustrate a window 20 provided in a wall 21, the window being substantially south-facing, Contained within a room adjacent the window are two items A, B to be protected from the sun.

Two opaque areas 22, 23 are provided initially towards the right-hand side of the window 20, as shown in Figure 2, these areas being so located as to cast a shadow on the items A and B early in the morning, when the sun is towards the east. Figure 4 illustrates the position of these opaque areas 22, 23 when viewed from the exterior of the window. During the course of the day, the described control arrangement will cause the opaque areas to move, as indicated by the dotted tracks 22', 23' until at the end of the day the opaque areas occupy the positions 22" and 23" as illustrated in Figures 2, 3 and 4.

This movement of each opaque area is controlled by the described microprocessor.

In order to create an initial opaque area or "mask" on a window, a software flow chart as illustrated in Figure 5 may be followed, the effect of the various procedural steps being illustrated in Figure 6. In order to create the mask a joy-stick is utilised. Initially the mask control sequence is initiated and a button is pressed to select an object identification letter which appears on an appropriate display screen. A double click of a button starts mask positioning. A flashing mask spot or "cursor" will appear at the centre of the window. By moving the joy-stick the flashing spot is located at a first position of the mask outline, as illustrated at the first stage of Figure 6. The button may be pressed to define this position. The Joy-stick may then be moved to re-locate the cursor at the corners of the desired mask area, the button being pressed at each corner area. There is a facility to erase parts or all of the mask outline if necessary by holding the button down. As the mask is created the outline of the mask is displayed on the window as an opaque line, and when the line forms the complete perimeter of a mask, a double depression of a control button causes the entire mask area to become opaque.

The erasure technique involves the re-commencement of the mask control sequence and the selection of the appropriate identification letter followed by a double depression of a button to start mask positioning. If the button is then held down, erasure of the mask may be effected.

It is possible to review and modify the mask. By operating the button appropriately a mask, located in position at any particular time, will simulate the movement to be followed by that mask area during the course of the day.

Alternative methods may be utilised for creating masks.

Alternatively, the hand-operated control unit 11 may incorporate a light sensor. The hand-operated unit 11 may then be located on the item of furniture or adjacent the item of furniture that is to be protected from direct sunlight, and initially the control unit 10 may be manually operated to set up an area of shade of a predetermined size surrounding the control unit 11. The micro-processor will be adapted then to maintain the control unit 11 in shade for the great proportion of the time. In such an arrangement, from time-to-time, the control unit 11 would cause the pixels of the window to be "scanned" in order to determine precise position of the sun relative to the window and the unit 11. Appropriate calculations could then be carried out to ensure that the item of furniture on which the unit 11 is resting is in shade.

While the window arrangement has been described above with reference to an embodiment in which a liquid crystal arrangement is utilised to make the window opaque, it is to be appreciated that other expedients may be adopted, such as a mechanical blind, shutters or fabric mask or the like suspended within or adjacent the window.

In a modified embodiment of the invention, particularly for use with horizontal windows, instead of utilising a liquid crystal material as described, an element of opaque material may be provided, means also being provided to move the element of opaque material adjacent the window in a direction parallel to the window. Thus the element of opaque material may be moved to cast a shadow at a predetermined point. The means for moving the opaque material may be computer controlled so that a shadow cast by the opaque material maintains in a substantially constant position regardless of the movement of the sun. Alternatively, the material may be transparent, but coloured, thus casting a coloured shadow. Such an arrangement may be used to provide an architectural effect, or to provide protection.

Figure 7 illustrates a pair of sunglasses 30. The glasses 30 incorporate, within the frame, a tilt sensor 31 adapted to determine the orientation of the glasses with respect to the vertical. Each of the lenses 32 of the glasses is formed of a "window" of the type described above incorporating a liquid crystal. The glasses, as described, will operate to adjust the opacity oi the lenses 32 in accordance with the sensed light, but also will adjust the opacity of the lenses in response to signals derived from the tilt sensor 31. Thus, if the sunglasses 30 are tilted so that the person wearing the sunglasses 30 is looking upwards, the lenses 32 will be made more opaque than if the glasses 30 are tilted so that the person using the glasses 30 is looking downwards. Thus, if a person wearing the glasses 30 looks up there is only a minimum change of his or her eyes being damaged by direct sunlight. Whatever the orientation of the glasses 30, if the lenses 32 are in a vertical plane, then the upper part of each lens 32 will be kept opaque, with the lower part of the lens 32 being more transparent.

Using a miniaturised microcomputer combined with a solid state tilting sensor, sunglasses can be controlled to allow for head movement so that sunlight is kept out oi the eyes. Maximum opacity may be arranged to occur when the person wearing the sunglasses is in a horizontal position and optimum transparency occur when the sunglasses are inclined towards the ground. Opacity could also be graduated under normal circumstances with the upper region oi the sunglasses being darker than the lower region. Figures 8A to 8F illustrate the manner in which the transparency of the sunglasses may be adjusted in different positions.

The light transmitting arrangement may also be applied to a vehicle window. By using sensors to detect external light sources which would affect the driver, sections of a controllable windscreen and windows could be darkened to achieve the effect of a sunvisor. Passenger windows could also be controlled automatically or by means of a control button. As with the sunglasses described above, a graduated opacity may be automatically provided so that the top of the windscreen 'visor' is darker than the rest of the windscreen (which is preferably left at maximum transparency).

INDUSTRIAL APPLICABILITY

The light transmitting arrangement may be used in a wide range of products ranging from windows in a building to a pair of sunglasses.

Claims

1. A light transmitting arrangement comprising a window provided with adjustment means for adjusting the opacity of the window and control means for controlling operation of the adjustment means, the control means being arranged to operate in dependence upon a signal from input means, other than just the output of a manual control or the output of a single light sensor.

2. An arrangement according to Claim 1 wherein the input means comprises touch sensitive means.

3. An arrangement as claiiaed in claim 2 in which the touch sensitive means is arranged to sense which part of the window is being touched so that the opacity of different parts of the window can be adjusted in dependence thereon.

4. An arrangement according to Claim 1 wherein the input means comprises means for indicating the position of a light source, such as the sun, relative to the window and which is arranged to adjust the opacity of the window in dependence upon movement of the light source relative to the window.

5. An arrangement according to claim 1 wherein the input means comprises at least one tilt sensor.

6. An arrangement according to Claim 5 in the form of a pair of glasses, each lens of the glasses comprising a said window.

7. An arrangement according to Claim 1 wherein the input means comprises two light level sensors positioned on opposite sides of the window, the control means being arranged to adjust the opacity of the window in dependence upon a comparison between the light levels sensed by the two light level sensors.

8. An arrangement according to Claim 1 wherein the input means comprises at least one sensor adapted to detect a person, vehicle or the like.

9. An arrangement according to Claim 8 wherein the said sensor is adapted to sense a person within a room provided with the window.

10. An arrangement according to Claim 8 wherein the said sensor is adapted to sense a vehicle or person near the exterior of the window.

11. An arrangement according to Claim 1 wherein the input means comprises a temperature sensor.

12. An arrangement according to any preceding claim wherein the adjustment means comprise a liquid crystal arrangement.

13. An arrangement according to Claim 12 wherein the window comprises two spaced apart sheets of transparent material, with liquid crystal material in the space between the sheets and electrodes for enabling a potential to be applied to the liquid crystal material.

14. An arrangement according to Claim 13 wherein the electrodes are formed of transparent material and are adapted to provide potential to discrete pixels of liquid crystal material.

15. An arrangement according to any preceding claim wherein the control means is adapted to receive control signals from a remote control device.

16. An arrangement according to claim 15 wherein the remote control device is adapted to transmit infra-red signals to the control means.

17. An arrangement according to any of the preceding claims wherein the control means comprises a micro-processor.

18. An arrangement according to Claim 17 wherein the control means is provided with manually operable control elements.

19. Any novel combination of features disclosed herein.