WO2003102668A1

WO2003102668A1 - A method and system for artificially creating and displaying a rainbow

Info

Publication number: WO2003102668A1
Application number: PCT/GB2003/002368
Authority: WO
Inventors: Marc Henri Eugene Quinn
Original assignee: Marc Henri Eugene Quinn
Priority date: 2002-05-31
Filing date: 2003-05-30
Publication date: 2003-12-11
Also published as: GB0428253D0; AU2003244751A1; GB2405490A; GB2405490A9; GB2405490A8; GB0212925D0

Abstract

A system (1) for artificially creating and displaying a rainbow to an observer (2) has a Tungsten lamp (3) and a fountain element (5) for producing a fountain (4) of water droplets. A bank (6) of mirrors directs light from the lamp on to the fountain. The mirrors are arranged into sets and the mirrors of each set are arranged in such a way to cause a virtually collimated beam of light to impinge on the fountain (4). The light is refracted and reflected by the water droplets of the fountain to create the visual effect of a rainbow to an observer (2) viewing the water spray from the direction in which the beams impinge on the water spray (4).

Description

A METHOD AND SYSTEM FOR ARTIFICIALLY CREATING AND DISPLAYING A RAINBOW

The present invention relates to a method and system for artificially creating and displaying a real rainbow to an observer viewing a fountain or other water spray, particularly in situations where there is little or no sunlight.

In nature, a rainbow is formed as the result of sunlight being refracted and reflected in airborne water droplets. However, attempting to create a rainbow by simply shining an artificial light source into a spray of water droplets will not succeed. The reason for this is that an artificial light source does not provide virtually parallel light, unlike the sun.

An object of the present invention is to provide a method and system for artificially displaying a rainbow to an observer. The invention aims to create a parallel source of light to mimic the sun's rays as they reach the Earth. From one aspect, the invention consists in a method of artificially creating and displaying a rainbow to an observer viewing a fountain or other spray of water droplets, comprising the steps of: projecting light from an artificial light source; causing the light from the artificial light source to produce at least one collimated or virtually collimated beam of light; and directing the collimated or virtually collimated beam(s) of light so as to impinge on the water spray, whereupon the light is refracted and reflected by the water droplets to create the visual effect of a rainbow to an observer viewing the water spray from the direction in which the beam(s) impinge on the water spray. The invention enables a rainbow to be displayed indoors as well as outdoors and the invention is best implemented at night or in overcast weather as artificial light cannot compete with the sun.

The light source should have an output covering the full visible light spectrum. For a rainbow to be visible, the angle between the light illuminating the water droplets and the light reflected by the water droplets and viewed by the observer needs to be between 40 degrees 15' 28" for violet light and 42 degrees 1' 52" for red light, the effective band width being 1 degree 46' 24". This angle is represented by the angle Y in Figures 1 and 6 of the accompanying drawings. The light source can vary in power depending on the installation requirements. The intensity of the rainbow depends on the size of the droplets forming in the water spray and adjusting the droplet size affects the rainbow created. For all colours to be seen, a droplet of greater than 0.8 mm in diameter is needed and the diameter of the droplet should preferably be in the range of 0.8 mm to 2.0 mm. In the case of producing virtually parallel light, the steps of collimating and directing light so as to impinge on the water spray may comprise directing a plurality of beams of light in such a way that the beams interfere with each other in the spray to reproduce the combined effect of a virtually parallel light beam. This may comprise directing a plurality of sets of beams of light in such a way that all the beams of each set interfere with each other in the spray to create such a beam of virtually parallel light. The light beams may interfere by overlaying one other, causing the interference patterns to cancel each other and create a pseudo parallel light source. The method may include the preparatory steps of placing a screen in the place where the water spray is to occur, and directing the beams of light in such a way that they interfere with each other at the screen. The screen may then be removed and the spray activated.

From another aspect, the invention consists in a system for artificially creating and displaying a rainbow to an observer, comprising: at least one artificial light source for projecting light; means for producing a spray of water droplets; means for causing at least one collimated or virtually collimated beam of light to be produced from light projected from the light source; and means for directing the collimated or virtually collimated beam(s) of light so as to impinge on the water spray, whereupon the light is refracted and reflected by the water droplets to create the visual effect of a rainbow to an observer viewing the water spray from the direction in which the beam(s) impinge on the water spray.

The directing means may comprise a reflector. The reflector is desirably adjustably mounted so that it can be adjusted to direct light in different directions. The reflector may be a parabolic reflector. The system may include a parabolic light source comprising a said light source and a said parabolic reflector.

In a preferred embodiment, the spray supplying means creates a "wall" of water droplets. The spray supply means may basically be a fountain which can be of any size.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:-

Figure 1 is a schematic view of a first embodiment of the invention;

Figure 2 is a detail of a bank of mirrors for the first embodiment; Figure 3 is a detail of Figure 2;

Figure 4 is a schematic view of a preparatory step for the first embodiment;

Figure 5 is a parabolic light source for the second embodiment; and

Figure 6 is a schematic view of a third embodiment.

Referring to Figures 1 and 2 of the accompanying drawings, a system 1 for artificially displaying a rainbow to an observer 2, comprises a divergent light source 3, such as a Tungsten lamp, for projecting light onto a fountain 4 of water droplets from a fountain element 5. The projected light is directed on the fountain by a wall or bank 6 of plane mirrors 7 mounted on a wall 8 (see Figure 2). The bank may have a hundred mirrors, each mirror having a square reflective surface which has sides of 10 cm.

Referring to Figure 3, each mirror 7 is glued to a plate 9 which is slid into a attachment 10 of the type used for a hotshoe connection in conventional camera equipment. The attachment 10 is part of an adjustable tripod style head 11 which is connected by a ball and socket universal joint 12 to a stud 13, wherein the socket 14 is connected to the attachment 10 and the ball 15 is at one end of the stud 13. The stud 13 extends through the wall 8 and has a wingnut 16 on the opposite side of the wall to the head 11 with a washer 17 between the wingnut and the wall. By unscrewing the wingnut 16, the adjustable head 11 and mirror 7 can be pushed in a forward direction away from the wall 8. The socket 14 has a lock screw 18 which engages the ball 15 and is adjustable to lock the head 11 in the desired direction.

In use, the light source 3 and the fountain element 5 are switched on. The mirrors 7 are arranged into sets of, say, five mirrors and the light reflected by each mirror from the divergent light source 3 is still divergent. However, the mirrors of each set are arranged in such a way that the light reflected from each mirror overlays, or is overlaid by, the reflected light from the other mirrors of the set so that the interference patterns are cancelled out creating a pseudo-parallel light source, and the overlaying is arranged to occur in the fountain 4 of water droplets. Each set of mirrors thus causes a beam of virtually parallel light to impinge on the spray of the fountain, enabling the rainbow effect to occur. The beams of virtually parallel light are refracted and reflected by the water droplets to create the visual effect of a rainbow to an observer 2 viewing the fountain from the direction in which the beams impinge on the water spray when the observer is within the viewing zone 19 shown dotted in Figure 1. The viewing zone is defined as being between light at the outermost edge of the outermost beams from the bank 6 of mirrors after it has been reflected by the water droplets at the angle Y. By having the light source 3 at a greater height than the bank 6 of mirrors, light reflected by the mirrors 7 and then by the water droplets reaches the ground, enabling an observer to be within the viewing zone 19. In order to set up the system 1 , a screen 20 is placed above the centre of the fountain element 5. The light source 3 is switched on and the position of each of the mirrors 7 of a set is adjusted as necessary so that the reflected light from each mirror overlay, or is overlaid by, the light reflected by the other mirrors of the set and form a single square of light on the screen. The mirrors of all the other sets are directed or focussed in the same way to form such squares on the screen 20 and the edge of each square is arranged to adjoin other squares. Once this is completed, the screen 20 is removed, the fountain is activated and a rainbow is created in the manner as previously described.

A mirror or reflector 21 of a second embodiment as shown in Figure 5, is integrated with the light source 22 to form a parabolic light source 23 wherein the mirror is a parabolic mirror 21 and the divergent light source 22 is mounted at the focus of the mirror and receives power via cabling 24. A bank of these parabolic light sources 23 replaces the bank 6 of mirrors and the light source 3 of the first embodiment, and the bank may have a hundred such parabolic light sources 23. Each parabolic light source is mounted on an adjustable head 11 like each mirror 7 of the first embodiment.

In a similar manner to the first embodiment, the bank is divided into a plurality of sets of parabolic light source whereby each parabolic light source 23 of each set forms a beam which overlays, or is overlaid by, the beams from the other parabolic light sources of the set in the fountain of water.

A third embodiment is shown in Figure 6, whereby the bank of parabolic light sources 23 is replaced by a large parabolic light source 25, such as a searchlight, mounted, for example, on a building or scaffold 26.

The third embodiment is for use outdoors, and is on a larger scale so that the viewing zone 19 is increased and the visual effect of a larger rainbow is created. The fountain 4 of water used in such an arrangement may be 15 metres high.

The advantage of the second and third embodiment is the integration of the mirrors and the light source as one unit. For the first embodiment, increasing the number of mirrors per 0.093 square metre (1 square foot) would continue to improve the effect by more closely reproducing a parabolic reflector.

All the above embodiments effectively create a parabolic surface which produces a parallel or near parallel columnar light source that mimics sunlight. To alter the apparent position of the rainbow the relative locations of the light source and the mirrors or parabolic light source(s), and the fountain must be altered. This is most easily done by adjusting the height of the mirrors or parabolic light source(s) above the ground. The parabolic light source or the bank of mirrors or parabolic light sources and the fountain of spray can be of varying size depending on the size of rainbow to be created.

Whilst particular embodiments have been described, it will be understood that various modifications may be made without departing from the scope of the invention. For example, individual mirrors or parabolic light sources of the bank may be arranged to be moved manually or automatically and the adjustable head may be replaced by a servo assisted remote control head. Any suitable means may be used to provide an adjustable mount for a mirror or a parabolic light source.

The bank of mirrors or parabolic light sources could be placed on the ground with the light being directed by the mirrors or parabolic light sources into the spray.

In an indoor environment, spray may be arranged to come from the ceiling.

It may be feasible to have a machine in which a reflector tracks the sun during daylight and an artificial source or sources of light take over at night or in low light conditions. With reference to the third embodiment, the searchlight may be replaced by a series of searchlights and the beams of the searchlights could be overlaid in the fountain.

Claims

CLAIMS:

1. A method of artificially creating and displaying a rainbow to an observer (2) viewing a fountain (4) or other spray of water droplets, comprising the steps of: projecting light from an artificial light source (3); causing the light from the artificial light source (3) to produce at least one collimated or virtually collimated beam of light; and directing the collimated or virtually collimated beam(s) of light so as to impinge on the water spray (4), whereupon the light is refracted and reflected by the water droplets to create the visual effect of a rainbow to an observer (2) viewing the water spray from the direction in which the beam(s) impinge on the water spray (4).

2. The method as claimed in claim 1 , wherein the steps of collimating and directing light so as to impinge on the water spray (4) comprises directing a plurality of beams of light in such a way that the beams interfere with each other in the spray (4) to reproduce the combined effect of a virtually parallel light beam.

3. The method as claimed in claim 2, comprises directing a plurality of sets of beams of light in such a way that all the beams of each set interfere with each other in the spray to create such a beam of virtually parallel light.

4. The method as claimed in claim 2 or 3, wherein the light beams interfere by overlaying one other, causing the interference patterns to cancel each other and create a pseudo parallel light source.

5. The method as claimed in any preceding claim, including the preparatory steps of placing a screen (20) in the place where the water spray (4) is to occur, and directing the beams of light in such a way that they interfere with each other at the screen.

6. The method as claimed in claim 5, including removing the screen (20) before the spray (4) is activated.

7. The method as claimed in any preceding claim, wherein the light source (3) has an output covering the full visible light spectrum.

8. The method as claimed in any preceding claim, wherein a said water droplet has a diameter of at least 0.8 mm.

9. The method as claimed in claim 8, wherein the diameter of the water droplet is in the range of 0.8 mm to 2.0 mm.

10. A system (1) for artificially creating and displaying a rainbow to an observer (2), comprising: at least one artificial light source (3) for projecting light; means (5) for producing a spray (4) of water droplets; means (6,7) for causing at least one collimated or virtually collimated beam of light to be produced from light projected from the light source (3); and means (6,7) for directing the collimated or virtually collimated beam(s) of light so as to impinge on the water spray (4), whereupon the light is refracted and reflected by the water droplets to create the visual effect of a rainbow to an observer (2) viewing the water spray from the direction in which the beam(s) impinge on the water spray (4).

11. The system as claimed in claim 10, wherein the directing means comprises at least one mirror (7,21).

12. The system as claimed in claim 10 or 11 , wherein the means for causing at least one collimated or virtually collimated beam comprises a plurality of mirrors (7) which are arranged in such a way that the light reflected from each mirror overlays, or is overlaid by, the reflected light from the other mirrors so that the interference patterns are cancelled out creating a pseudo-parallel light source.

13. The system as claimed in claim 10 or 11 , wherein the directing means and the means for causing at least one collimated or virtually collimated beam together comprise at least one parabolic mirror (21), the or each mirror having said artificial light source (22) mounted at the focus of the mirror.

14. The system as claimed in claim 11 , 12 or 13, wherein each mirror (7,21) is adjustably mounted so that it can be adjusted to direct light in different directions.

15. The system as claimed in any one of claims 10 to 14, wherein the spray producing means (5) creates a "wall" of water droplets.