Mood lighting is now an accepted and desirable addition in modern homes, enabling occupiers to select lighting levels and patterns appropriate to their mood and planned activities.

Lighting manufacturers have responded to this demand by producing equipment ranging from very simple devices incorporating a single source of light (which may optionally be dimmable), to more complex devices with several light sources, some capable of colour change or even'moving'light patterns.

It is an object of the present invention to provide an apparatus which can be used for mood lighting.

Accordingly the present invention provides a lighting apparatus comprising a source of illumination, a reservoir of liquid and means for inducing ripples on the surface of the liquid, wherein said apparatus is arranged to project an image of the ripples into a room.

In at least its preferred embodiments the present invention therefore provides a system which a user may configure to his/her liking very easily. The system can have such flexibility that it is attractive to followers of Feng Shui by which it is believed that spaces within the home can be endowed with appropriate energies by configuring the lighting apparatus appropriately.

The means for inducing ripples could comprise means arranged to drop into the liquid from a above-e. g. drops of the liquid itself could be released over the surface of the liquid. Preferably however the means comprises one or more actuators contacting the surface of the liquid. Such an actuator could comprise a pendulum suspended from above the liquid but preferably

it is arranged to float on or be submerged in the liquid. In this case the actuator is preferably magnetic or magnetisable. The magnetism may be permanent-e. g. by virtue of the actuator including a permanent magnet-or it may be temporarily induced by an external magnetic field.

Such arrangements are particularly advantageous as they allow the actuator to be moved by an external magnetic field without any physical connection to the actuator. Thus the need either for a driving means above the surface of the liquid to support the actuator or one passing through the reservoir, is obviated.

Furthermore cleaning of the liquid reservoir is facilitated.

This arrangement is novel and considered particularly beneficial and thus when viewed from a further aspect the present invention provides a lighting apparatus comprising a liquid reservoir, a magnetic or magnetisable actuator for causing ripples on the surface of the water, electromagnetic means for creating a magnetic field to drive said actuator and a light source arranged to illuminate the liquid in such a way as to project an image of said ripples.

Thus the electromagnetic means causes the actuator to move by producing a varying magnetic field so as to attract or repel the magnetic or magnetisable actuator.

If, as is preferred, the electromagnetic means is provided outside the liquid reservoir, such an arrangement is also particularly easy to clean.

Preferably the electromagnetic means is arranged below the liquid reservoir such that the actuator can be made to execute vertical movement in the water to generate the ripples.

It will be understood by those skilled in the art that the distance between the magnetic/magnetisable actuator and the electromagnet is critical since the force that the latter can exert on the former is

inversely proportional to the cube of the distance between them. This could be problematic where, for example, a user was expected to refill the reservoir with liquid since, with a floating actuator, if the reservoir were to be over-filled only slightly the reduction in magnetic force could be great enough to prevent proper operation of the apparatus. Preferably therefore a magnetic field concentrating member is provided in the reservoir. Such a member preferably comprises a temporarily magnetisable material having a relatively high magnetic permeability, e. g. ferrite.

Preferably it is covered or coated to prevent corrosion in the liquid.

It will be appreciated that by virtue of providing such a member, the magnetic field in the vicinity of the actuator may be enhanced for a given separation between the electromagnet coil and the-actuator, thereby making accurate filling, for example, less critical.

The field concentration member could be physically separate from the rest of the electromagnet means-e. g. attached to the floor of the liquid reservoir.

Alternatively the field concentration member could be in contact with or integral with a core of the electromagnetic means. Thus for example the base of the liquid reservoir could be locally deformed around an extension to the core of an electromagnet below the overall level of the base. This is particularly facilitated where, as is preferred, the reservoir is moulded from plastics.

Preferably the apparatus comprises means to locate the actuator laterally. Such means could be provided by forming one of the actuator and field concentration member with an elongate portion for cooperating in use with a corresponding recess on the other. Such an arrangement would allow the actuator to slide vertically but would have the desired effect of locating it laterally. Alternatively lateral location may be

provided magnetically-e. g. by providing a degree of permanent magnetism to the core of the electromagnet and/or the field concentration member, if provided. In one preferred embodiment a permanent magnet is provided on one end of the core of the electromagnet.

Preferably the apparatus-comprises a shield or the like over the liquid reservoir, most preferably a dome, e. g. a part-spherical dome. The shield could be clear, so as to transmit the image of the ripples therethrough -e. g. onto the wall of a room. Alternatively the shield could be translucent or semi-translucent so that the image appears on the outside of the shield.

The electrical signal used to drive the electromagnetic means may be derived from any convenient source. For example it could be generated randomly, or a regular signal could be provided, preferably the characteristics of which, such as the frequency and/or amplitude, can be controlled by a user. Alternatively an external signal such as a music signal, e. g. the bass notes thereof, or a predetermined signal pattern could be used. In one specific example of the latter, a repeating signal reducing in frequency from 12 Hz to 0.25 Hz over 20 minutes is used.

The light source may be placed at any convenient position-e. g. above the liquid. Preferably however it is placed below the liquid so that light is transmitted through it. It may illuminate the liquid directly or by means of a mirror. This may be convenient in allowing the light source to be to one side of the electromagnetic means and thereby reduce the depth of the apparatus.

The liquid may be clear, semi-clear or translucent.

Preferably water is used. Floating or submerged objects or a second, immiscible liquid, may be provided in the liquid to provide interesting patterns. Similarly the liquid may be coloured.

The actuator my be any convenient shape, but

preferably it is downwardly bevelled since this has been found to enhance ripple propagation.

The actuator may be arranged simply to execute a vertical movement in the liquid in order to generate ripples. In some preferred embodiments however it is also arranged to execute a rotational movement. Where the actuator is mechanically driven this may be achieved simply by coupling it to a suitable motor. Where the actuator is magnetically driven however it is preferably achieved by providing the actuator with means for imparting a torque to the actuator from the vertical movement in the liquid. Preferably such means comprises one of more flexible fins e. g of polythene or acetate.

Such fins will be made to execute a flipper-type movement as the actuator reciprocates vertically thereby exerting a small force normal to the direction of reciprocation. By arranging the fin or fins suitably on the actuator, e. g on an edge thereof, this force can be made to exert a torque and thereby cause the actuator to rotate. The rotating actuator could be arranged to drag floating objects around to create further patterns.

It is also preferred in such embodiments to provide one or more additional fins, preferably also flexible, in a different, preferably orthogonal, plane. It has been found that by providing such fins it is possible to reduce the tendency of the actuator to rock about an axis at right angles to the axis of rotation.

Certain preferred embodiments of the invention will now be described, by, way of example only, with reference to the accompanying drawings in which: Fig. l is a cross-section through an apparatus in accordance with the invention ; Fig. 2 is a close-up view showing the arrangement of the actuator and the driving electromagnet; Fig. 3 is a plan view of the apparatus with the dome shown in cross-section ; Fig. 4 is a plan view the actuator of a second

embodiment; Fig, 5 is a close-up cross-section showing a cross- section through actuator of Fig. 4; Fig. 6 shows variation of the actuator in Fig. 4; Fig. 7 shows an actuator arrangement in accordance with a third embodiment; and Fig. 8 shows a fourth embodiment of the invention.

Figures 1 to 3 show a preferred embodiment of the invention, where a point light source (1) rests centrally within a base (2) upon which stands a spherical translucent globe (3). The globe (3) has a flat bottom of a diameter to suit the base (2) and a ventilation hole (4) at the top to allow a through flow of air and prevent condensation inside the globe (3).

Resting horizontally within the globe (3) is an octagonal tray (5) with raised sides (9) containing water (6). Conveniently the globe (3) may be split horizontally to assist assembly. Attached to the underside of the tray in the centre is an electromagnet (8) fed from a remote power supply (not shown), capable of inducing movement in an actuator (7) located in the tray (5) and situated above the electromagnet (8). The actuator (7) may either rest on the bottom of the tray (5) or may float on the surface of the water, and is maintained in position by means of a permanent magnet embedded within it, which permanent magnet is continuously attracted to the ferrous core of the electromagnet (8).

One example of a floating-version of an actuator is shown in Figure 2. The actuator (7) floats on the surface of the water (6), being maintained in position by the small permanent magnet shown contained within its base. In close proximity to the aforementioned actuator is an electromagnet (8) secured to the underside of the tray (5) containing within its core another permanent magnet 10 which continuously attracts the aforementioned permanent magnet housed within the base of the actuator

(7). Whenever current flows within the electromagnet (8), the actuator (7) is attracted towards the electromagnet causing it to dip in the water resulting in a ripple 12 propagating from the actuator outwards towards the edges of the tray (5).

As may be seen from the plan view of Fig. 3, the circular and octagonal shapes of the dome 3 and tray 5 respectively define a ventilation gap 14 between them.

In use the light source (1) is turned on and pulses of current fed to the electromagnet (8) to induce ripples on the surface of the water (6). The frequency and duration of the current pulses can preferably be adjusted by the user to achieve the desired effect.

Images of the ripples will be projected. upwards and outwards: if the globe (3) is semi-translucent, the ripple images will also appear on the upper surface of the globe (3).

Fig. 4 shows an actuator. from a second embodiment.

In this embodiment the actuator 16 comprises an elongate beam 18 having flexible polythene fins 20 attached at either end and respective sides thereof. A small permanent magnet 22 is embedded in the centre of the beam 18. Fig. 5 shows a cross-section through the actuator 16 in situ. It may be seen from this that the beam 18 has a bevelled profile.

In use the actuator 16 is made to reciprocate in the water by the electromagnet 8 as described previously. This causes the fins 20 to flap in the water thereby exerting a torque on the actuator in the direction of the arrows A. This causes the actuator 16 slowly to rotate in the liquid. In an alternative embodiment an additional beam identical to the first could be attached at right angles to it to give a generally cruciform shape.

A variation of the actuator described above is shown in Fig. 6. This is identical to the actuator shown in Fig. 4 except that in this embodiment two

further flexible fins 24 are provided on the beam 18 of the actuator 16. These additional fins 24 are orthogonal to the main fins and serve to counteract any tendency of the actuator to rock backwards and forwards in the vertical plane in addition to the translational reciprocation induced by the electromagnet 8.

Fig. 7 shows a further embodiment of the invention.

In this arrangement the actuator 30 is a bar magnet which rests on a fulcrum bar 32. As well as the core of the electromagnet 8 being premagnetised by a permanent magnet 10 in order to locate one end of the actuator 30, a second permanent magnet 34 is provided to locate the other end and thereby keep the actuator balanced on the fulcrum 32 when no current is passed through the electromagnet. This second magnet 34 is glued to the underside of the glass tray 5.

In use the bar magnet actuator 30 is made to rock to and fro on the fulcrum 32 in response to a varying magnetic field generated by the electromagnet 8. The actuator 30 may simply be pulled off the fulcrum 34 in order to clean it.

Figure 8 shows a fourth. embodiment of the invention. In this embodiment a field concentration member in the form of an iron rod 25 is provided in water reservoir 5. As will be seen, the rod 25 penetrates the base of the reservoir 5 so as to be able to touch the top of the core 36 of the electromagnet 8, thereby meaning that the rod 25 effectively acts as an extension to core 36. The effect of this is to focus the magnetic field from the electromagnet 8 onto the magnet 38 in the actuator 26. By shortening the effective separation of the electromagnet 8 and the actuator 26 in this way, a greater force may be applied to the actuator.

It will also be seen that the magnet 38 in the actuator 26 is located in the vicinity of a recess 40 formed in the actuator. This recess 40 accommodates the

iron rod 25, thereby locating the actuator 26 laterally, whilst allowing it to move up and down. The clearance between the rod 25 and the walls of the recess 40 has been exaggerated for purposes of clarity. It will also be seen that unlike e. g. in Fig 2, no permanent magnet 10 is needed at the bottom of the core 36 in order to locate the actuator.

The features of the embodiment of Fig. 8 could equally be used in other embodiments-e. g. that of Figs. 4 to 6.

It will be appreciated that the foregoing descriptions are merely some of the many possible implementations of the invention and that many variations and modifications are possible within the scope of the invention.