GB2349942A

GB2349942A - Lamp comprising a plurality of coloured light sources

Info

Publication number: GB2349942A
Application number: GB0005918A
Authority: GB
Inventors: Alan Edgar Hatherley
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-03-09
Filing date: 2000-03-09
Publication date: 2000-11-15
Anticipated expiration: 2020-03-09
Also published as: GB9905408D0; GB0005918D0; GB2349942B

Abstract

A lamp comprises a translucent cover 10 containing a plurality of differently coloured light sources 12, 13, 14 and control means 15 for continuously and independently varying the intensities of the light sources. The cover 10 may be substantially spherical. The light sources 12, 13, 14 may be incandescent lamps and are preferably red, green and blue. The control means 15 may comprise a plurality of oscillators 22R, 22B, 22G, one for each light source. The control means may cycle the intensities of the light sources at rates with periods of the order of 10 s and the rates for each light source may be approximately equal and randomly or pseudo-randomly associated to each other.

Description

2349942 1 he present invention relates to lighting devices.

The primary purpose of a simple light is to illuminate a room or similar space, and such a light consists essentially of a luminous element. A develop ment of such lights involves directing the light onto a reflective surface such as a well or ceiling.

Lights of a different nature are known, however, in which the light is intended as much as or more for ornament or interest as for simple illumination. There is a wide variety of such lights, some of which are static and others of which involve some form of changing appearance. The latter type includes such widely different lights as revolving mirror lights used in ballrooms, lava lamps, and table-top fibre optic lights containing a set of differently coloured light sources and a rotating disc or the like which cycles slowly to couple the light sources to the fibres in a predetermined sequence.

The general object of the present invention is to provide a new form of lamp of the latter type.

According to the invention there is provided a lamp comprising a translucent cover containing a plurality of differently coloured light sources and control means for continuously varying the intensities of the light sources independently.

The cover can conveniently be substantially spherical, and its translucency is preferably such that no significant details of its contents can be perceived though it. The light sources can conveniently be Incandescent lights, having bulbs of coloured but transparent glass, and mounted in a cluster at or towards 'the bottom of the cover. There are preferably 3 light sources, preferably having colours of or close to the 3 primary colours (red, green, and blue).

The control means preferably cycle the intensities of the light sources at cycle rates with periods of the order of around 10 s; the frequency may be chosen to match the inverse of one or more of the natural brain frequencies such as the alpha, bets, or theta rhythms. A frequency in the region of 0. 14 Hz has been found to produce attractive results. The light sources are preferably cycled at individual rates which are approximately equal but are randomly or pseudo-randomly related to each other, so that exact repetition of the combined cycling is avoided. The control means may conveniently comprise a plurality of oscillators, one for each light source.

The present lamp is, as stated above, intended as much as or more for ornament or interest as for simple illumination. However, it may also be psychologically therapeutic, having a soothing or tranquillizing effect in suitable circumstances, and may be used, either alone or in combination with other lightIng, in situations where a -soothing effect on those in the vicinity is desired.

A lamp in accordance with the invention will now be described, by way of example, with reference to the drawings, in which.

Fig. 1 is a vertical section through the lamp; Fig. 2 is a block diagram of the control means; and Fig. 3 is a circuit diagram of an oscillator of the control means.

Referring to Fig. 1, the main body of the lamp consists of a generally spherical cover 10 with a supporting plinth 11 on which are mounted three incandescent lights 12-14 forming a cluster, and a control unit 15. The cover 10 is of white translucent material which diffuses substantially all light falling on it, so that effectively nothing of whatever structures are inside it can be seen.

The three lights 12-14 are red, green, and blue respectively, and have clear (non-translucent) glass, so that none of them casts a shadow as a result of being between another of the lights and a part of the cover 10. The lights 12-14 are mounted close together and are preferably relatively small compared to the size of the cover 10, so that each illuminates the inside of the cover 10 fairly. uniformly. This avoids appreciable colour variation over the surface of the cover.

Fig. 2 shows the control unit 15 in block form. An ordinary mains supply 20 feeds a power supply unit 21 which produces a low voltage DC power supply. Three free-running analog oscillators 22R, 22G, and 22B are energized from the power supply unit. Three switching units 23R, 23G, and 2313, which may convenientlY use SCRs (triacs), are fed with the mains supply 20 and feed the three respective incandescent lights 12-14. The switching units are controlled by the respective oscillators.

In operation, the three oscillators are all tuned to run at approximately 0.07 Hz. Each produces a sine wave, and each switching unit modulates the power fed to its respective light accordingly. Each light therefore oscillates between dim (or dark) and bright (full power) at around 0.07 Hz. The outputs of the three lights will therefore combine to produce a continuously varying colour. Since the oscillators are independent, their outputs will combine to produce a continuously varying colour which never repeats exactly. Further, since the oscillators are analog, their cycles will vary slightly as a result of component drift with time and temperature, so even if two oscillators happen to reach related frequencies, that relationship will not be maintained.

If desired, a balancing circuit (not shown) may be provided to prevent very dim moments. Such a circuit may, for example, combine the outputs of the three oscillators and feed an additional signal to the switching circuits if the combined signals from the oscillators falls below a preset minimum.

Fig. 3 is a partial circuit diagram of the control unit. The power supply unit 21 consists of a rectifying diode DI, a dropping resistor RI, a zener diode W1, and a capacitor Cl. This feeds the three oscillators 22R, 22G, and 2213, only one of which, 22R, is shown. Oscillator 22R has a transistor TRI with its collector coupled to its base via a 3-stage RC circuit, and driving an output transistor TR2. The switching circuit 23R consists of a triac SCRI with its base coupled to the output of transistor TR2 of the oscillator 22R. The light 12 is connected in series with the triac SCRI across the mains supply 20.

The lamp cycles between being turned fully off, or nearly so, at one extreme of the oscillator output signal and fully on at or near the other extreme of the oscillator output. The control circuitry for the triac is suitably arranged to achieve this. For the near-off lamp state, a variable resistor RIO is coupled f rom the triac's output back to its input as shown, and is adjusted so that the lamp just turns on if the oscillator 22R is disabled to produce a steady output. For the nearfully- on state, the components are suitably chosen so that the lamp - 4 approaches or reaches the fully on state at the other extreme of the oscillator output signal.

The oscillator 22R is tuned to approximately 0.14 Hz. One or more of the resistors in the RC chain in the oscillator may of course be made variable, to allow the frequency to be varied if desired.

It will be realized that several similar lamps, of the same or different sizes, may be driven in parallel from a single control unit. If desired, a single oscillator may drive differently coloured bulbs in different lamps, so that the lamps follow matching but different colour sequences.

The lamp as shown is spherical with a simple flat plinth. Obviously different shapes, either abstract or representational, may be used for the lamp, and the plinth may similarly have more ornamental shapes. If desired, the main body may be mounted on a standard above a base plinth. If desired, the lamps 12-14 may be housed in the base of the plinth and coupled to the main translucent body via optical cables.

It will of course be realized that the control unit may use a high frequency oscillator the output of which is divided down by digital counting techniques to generate the signals required to control the lights 12-14. If this is done, it is desirable for the divisors for the three lights to be such that the period required for any two of them to repeat their phase relationship should be very large. It may also be desirable to include a random or pseudo-random dither to prevent exact repetition of the colour sequence of the three lights in combinetion. Alternatively, if desired, the oscillators 22 may be provided with controls whereby their frequency can be adjusted.

The control unit may of course be incorporated into the plinth.

If desired, switches may be provided between the oscillators 22 and the switching units 23, to enable a remote control unit (not shown) to be used to control the cycling of the lights. Also, the control unit may be adjustable to permit different supply voltages and/or lamp voltages and/or powers to be used.

elk:[ m 1 A lamp comprising a translucent cover containing a plurality of differently coloured light sources and control means for continuously varying the intensities of the light sources independently.

2 A lamp according to claim 1 wherein 1-he cover is substantially spherical.

3 A lamp according to either previous claim wherein the light sources are incandescent lights having bulbs of coloured but transparent glass and are mounted in a cluster at or towards the bottom of the cover.

4 A lamp according to any previous claim wherein there are 3 light sources.

A lamp according to claim 4 wherein the lamps have colours of or close to the 3 primary colours (red, green, and blue).

6 A lamp according to any previous claim wherein the control means cycle the intensities of the light sources at cycle rates with periods of the order of 10 s.

7 A lamp according to any previous claim wherein the control means cycle the light sources at individual rates which are approximately equal but are randomly or pseudo-randomly related to each other.

8 A lamp according to any previous claim wherein the control means comprise a plurality of oscillators, one for each light source.

9 A lamp substantially as herein described and illustrated.

Any novel and Inventive feature or combination of features specifically disclosed herein within the meaning of Article 4H of the International Convention (Paris Convention).