WO2002063407A1

WO2002063407A1 - A device for generating multi-coloured light and a control system for controlling the operation of such a device

Info

Publication number: WO2002063407A1
Application number: PCT/DK2002/000091
Authority: WO
Inventors: Steven Scott; Søren Jensen
Original assignee: Hermetic Light Aps
Priority date: 2001-02-08
Filing date: 2002-02-08
Publication date: 2002-08-15

Abstract

A device for generating multi-coloured light (101), comprising two or more individually coloured light sources (103). The light sources (103) are mounted inside a housing (102) which has at least one surface permitting light to escape from the housing. The device further comprises a control system for individually controlling the power fed to each of the light sources (103) and thereby controlling the intensity of each of the colours so that the colour of the light escaping from the housing (102) may be varied. The control system is programmed to, during operation, always feed at least a minimum power level to each of the light sources (103) so that the light escaping from the housing (102) is always a mixture of all the colours of the light sources (103).

Description

A DEVICE FOR GENERATING MULTI-COLOURED LIGHT AND A CONTROL SYSTEM FOR CONTROLLING THE OPERATION OF SUCH A DEVICE

Technical field

The present invention relates to a device for generating multi-coloured light and a device for controlling the operation of such a device. The device may be used as a lamp in an outside or an indoor environment, such as for illuminating the interior or exterior of a building.

Background of the invention

Various lamps and light emitting devices are known from the prior art.

Swedish Patent Application SE 390 830 discloses a road sign with an interior light source which is characterised by a front reflection grid for partially reflecting light from an exterior light source, such as a headlight of a car. The arrangement is aimed at providing at least some visibility of the sign in the dark in case the interior light source is out of order.

UK Patent Application, GB 2 183 387 is concerned with a display device for use in signboards, information or directional signs, indoor or outdoor ornamental plates, lamp shades, clockfaces or the like. The display device is formed with a display plate of fine meshes of variously extending lines in various colours. The display plate is overlapped by a moveable shading plate with the same or different meshes. A plurality of fluorescent light sources are provided inside the device.

United States Patent US 5,309,656 discloses a flashing advertising sign for indoor use, and the patented invention is primarily concerned with a light-diode arrangement for causing on- and off-flashing of the light-diodes.

International Patent Application WO 95/31802 discloses a sign box having a viewing window allowing the presentation of a set of indicia (e.g. a sign) within the box, and having an internal fluorescent lamp capable of producing or not producing light on a repetitive basis.

German utility model application 200 02 060 discloses a lamp with at least two light sources which may emit light of different colours, so that the colour of the light emitting from the lamp may be varied. The document states that the lamp is primarily for use in indoor lighting appliances with the aim of compensating for varying daylight intensity. The document further discloses different colour temperatures of the two light sources. The control system of the lamp has a hand-controlled dimmer for varying the light intensity of the light emitting from the lamp and a microprocessor for varying the power distribution between the two light sources.

European patent application 0 790 457 shows a device for emitting light of varying colours. The device comprises four light sources (red, green, blue and white). The light sources may be filament lamps provided with filters or fluorescent lamps. Each light source is controlled independently so as to switch it on and off, and so that the luminous intensity may be varied gradually from zero to a maximum value. The document refers to the light emitting from the device as "beams".

United Kingdom patent application 2 288 903 discloses a device comprising four light bulbs (red, yellow, green and blue). The bulbs are independently controlled by four light dimmers, so as to vary the colour of light emitting from a housing within which the bulbs are arranged. The description mentions that the light bulbs may be one of several appropriate types, for example ordinary glass incandescent bulbs, tungsten bulbs, reflector bulbs, halogen bulbs, fluorescent tubes, discharge lamps or light emitting diodes. The change of colour may happen in response to an audio signal.

International patent application WO 99/37904 relates to a luminaire or lamp with an array of red, green and blue light emitting diodes with a control system for adjusting the individual components to maintain a desired colour balance in white coloured light being emitted from the lamp. A dimmer is included for controlling the overall light intensity.

French patent application 2 613 037 discloses a cylindrical housing for a lamp.

Description of the invention

It is an object to provide a device which may emit light of a plurality of colours, wherein the colour of the emitted light can be varied easily and rapidly. It is a further object of the invention to provide a device which is cheap to manufacture and which is easy to operate. It is a still further object of the invention to provide a device which can be formed in various shapes and sizes. It is a still further object of the invention to provide a control system for controlling the colour of light escaping from the device, and a method for controlling the colour of light. It is yet another object of the invention to provide a device which prevents flickering and abrupt changes in colour and/or light intensity when the colour of the light escaping from the device is varied. Thus, in a first aspect the invention provides a device for generating multi-coloured light, comprising:

- at least a first and a second electrically powered light source for emitting light of a first and a second colour, respectively, - a housing for housing the first and second light sources and having at least one surface through which light emitted from said light sources may escape,

- a control system for individually controlling the power fed to the first and second light source, respectively,

- the control system being adapted to supply each of said light sources with at least two power levels, whereby the colour of the light escaping from the housing may vary in accordance with the level of the power supplied to the light sources,

- the control system being programmed to, during operation of the device, always supply each of the light sources with at least a predetermined minimum power level, so that the light escaping from the housing is always obtained by a mixture of the light emitted from the at least two light sources.

It will be appreciated that by controlling the power levels, the colour of light emitted from the at least two light sources may be varied due to the fact that different light intensities are emitted from each of the two light sources. It is possible to create white light by mixing for instance the colours dark magenta and dark yellow green or, alternatively, the colours dark amber and deep blue.

By always supplying each of the light sources with at least a predetermined minimum power level during operation of the device, it is assured that none of the light sources are turned on or off. This prevents flickering and abrupt changes in colour and/or light intensity. It should be understood that all of the light sources may be completely switched off, i.e. to zero power, when no power is fed to the device, for example when the power supply is cut off at a main electrical contact. However, once the device is switched on and emitting light, the control system of the device assures that no one of the light sources is ever switched completely off, but that a small amount of power is always supplied to those light sources which emit light of a colour which is not desired in the light escaping from the device.

The device may be used as a module in building and designing of illumination devices. It may be used as an illumination device in industrial environments, in factories, offices, corridors, hallways, airports, train stations, concert halls, etc. When designed appropriately, it may also be used as a designer lamp for museums, luxury homes or offices, etc. The surface through which light may escape from the device may be a plane or a three- dimensional surface, such as a cube or a sphere made from an opaque material, such as glass.

The device according to the invention does in itself have the ability to be viewed as a light emitting object. The light sources may be arranged in such a way that they cannot be seen, i.e. in such a way that no direct light but only light reflected by walls of the housing or further reflecting means in the housing escapes through the opening. Thus, the light emitted from the device has no or little risk of blinding, and the emitted light is softer than direct light.

Preferably, the predetermined power minimum level corresponds to 0.1 - 5% of a maximum power level which the control system may supply to the respective light sources, such as 0.25 - 4%, such as 0.5 - 2%, such as 0.75 - 1.5%, such as approximately 1%. In the present context, the maximum power level should be understood as the power level which provides a maximum light intensity from each light source. The control system may be adapted to limit the power fed to the light sources, even though the main power supply of the device, e.g. a 110 V or 220 V power supply of a usual power distribution network, may supply higher power levels. In that case, the maximum power level should be understood as the maximum power level which may be provided by the control system to the light sources.

The device may comprise at least a first screen arranged in the housing in such a way that at least a portion of the light emitted from the light sources is reflected by the first screen. Thus, light emitted from the light sources may be reflected by the screen onto inner walls of the housing, the inner walls of the housing being adapted to reflect light, so that light reflected from the inner walls of the housing may escape trough the screen or may be reflected by the screen. Thereby, an illuminated three-dimensional space is provided inside the housing whereby the light escaping from the housing may be evenly distributed over the surface. Due to the reflection and possible re-reflection caused by the first screen, the light may escape from the device in not only a single direction but in a plurality of directions and preferably all directions, i.e. all directions within a solid angle of 180°. The reflection effects described above may be further improved by a second screen placed in the housing in such a way that at least a portion of the light emitted from the light sources, from the inner housing walls or first screen is reflected by the mesh.

The first and second screens are preferably semitransparent. Thus, the screens may be made from a coloured or opaque material allowing only a part of the light to pass through the screens. The first and second screens may be made from a woven or a non-woven material. In case of a woven screen, the screen has a slightly uneven surface which may contribute to diffusing and reflecting light.

The first semitransparent screen is preferably arranged at the front of the housing and may define the surface through which light emitted from the light sources may escape. The second semitransparent screen is preferably arranged in a vertical plane between a back and a front of the housing. Further reflection and diffusion may be achieved when the first and second semitransparent screens have different reflection characteristics. In case the semitransparent screens comprise meshes, such as perforated plates, at least one surface of such meshes or plates may be made from or coated with a reflecting material in order to improve reflection and thus diffusion of the emitted light. Similarly, the inner housing walls may be made from or coated with a reflecting material.

A third electrically powered light source for emitting light of a third colour may be provided. Any combinations of colours may be provided, but in a preferred embodiment of the invention, the three colours comprise red, green and blue, whereby light colours from white to black (no light) may be provided. The light sources may be arranged in groups, each group comprising a first, second and optionally a third light source. The groups of light sources may be evenly distributed within the housing, so as to achieve further distribution of the light. Each of the light sources preferably comprises a fluorescent tube, such as an argon tube, a neon tube, or a combined argon-neon tube. The light sources may comprise RGB tubes, e.g. Tecnolux™ tubes which in a preferred embodiment are made of coloured glass containing 100% Argon gas, such as:

Ruby Red Argon N18, for emitting light with wavelengths between 640-680 nm (nano meters), peak 660 nm. Brilliance: 786 cd/m² (Candela pr. m²).

Lite Green N20, for emitting light with wavelengths between 510-570 nm, peak 540 nm. Brilliance: 6883 cd/m².

Cobalt Blue N16, for emitting light with wavelengths between 420-490 nm, peak 440 nm. Brilliance 867 cd/m².

The above brilliances are for tubes of a diameter of 15 mm at a current level of 50 mA.

Preferably, the tubes are arranged within the housing with a mutual distance which is sufficiently large in order to avoid electromagnetic effects. Alternatively, or additionally, the housing may be made from a non-magnetic material, such as plastics or wood. In comparison to known device comprising conventional light bulbs, the device according to the present invention has several advantages. Firstly, the colour of the light may be varied substantially instantaneously, the speed at which the colour may be varied being limited only by the reaction time of the involved electronic components of the control system. Further, in case of a control system which is capable of performing ungraduated control of the power fed to the light sources, and thus the light colour, many more different colours may be created than those which may be created in conventional systems comprising filters or coloured light bulbs. Moreover, the power fed to the light sources is more efficiently utilised in a device according to the invention than in conventional system incorporating light bulbs and possibly filters, as only the amount of power needed for each base colour (for example red, green and blue in a RGB system) is fed to the light sources. No or only little power is absorbed by filters. Thus, the intensity of the light escaping from the device may be higher than in conventional devices. Moreover, the output from a light does not usually reach its maximum until the light bulb is heated to a certain temperature, whereas by appropriate selection of light sources, this problem is avoided in a> device according to the invention.

Furthermore, a fourth electrically powered light source for emitting light of a fourth colour may be provided. Apart from augmenting the number of different light colours, this also has the effect that a weak point in the spectrum of a set of light source, e.g., RGB-tubes, may be compensated for, e.g. by adding a yellow light source to the RGB-tubes.

The housing may further house at least one transformer, at least one dimmer for individually regulating the power supplied to each of the light sources, and a control system for controlling operation of the at least one dimmer. The control system may comprise a microcomputer which can be loaded with a computer program, and the computer program may be adapted to load a set of data into a memory of the control system. The set of data may represent power levels to be supplied to the light sources, and the computer program may further be adapted to cause the control system to control the power levels supplied to each of the light sources in accordance with the power levels represented by the set of data.

The transformer preferably transforms 50 Hz AC 230 V to 2000 V AC, or 60 Hz AC 110 V to 2000 V AC. Some standard available switches require a voltage below 1000 V, in which case the device may comprise a transformer that transforms 50 Hz AC 230 V to 990 V AC, or 60 Hz AC 110 V to 990 V AC. The output of the transformer may be 25mA. The transformer may be a conventional iron core transformer or an electronic transformer, such as an electronic transformer with a high switching frequency, such as 32 kHz. In order to avoid interference between two systems of transformers and cables, such as a system for feeding a red light source and a system for feeding a blue light source, the transformers and cables are preferably arranged with a mutual distance, such as 10 - 50 mm, such as approximately 30 mm. The same distance may be provided between the light sources, such as between light tubes. In order to avoid interference between the device(s) and the surroundings, the device may be placed sufficiently distanced from surrounding devices of the same kind as well as from surrounding metal objects. Alternatively, the housing of the device may be may with wall which provide a shield to electromagnetic interference.

Due to the fact that no or only few mechanical parts, such as moveable filters, are involved in changing the light colour the colour of the light escaping from the device may be rapidly varied, the speed of change being limited only by the response time of the involved electronic components, such as the dimmer or dimmers.

The control system may be operable by at least one switch or touch sensor arranged on an outer surface of the housing, and/or by a remote control. The remote control may preferably be of the infrared (IR) type.

The control system may comprise an input for inputting data in the form of an electrical signal provided by an output of a sound system, and the microcomputer may be adapted to compute, based on the electrical signal, the power levels to be supplied to the light sources. Thus, the colour of the light emitted from the device may vary in accordance with, e.g., sound level, sound pitch, rhythm, sound style, etc. The input of the control system may be connected to a computer system via a serial connection, such as a USB (Universal Serial Bus), via a modem, via an ethernet connection, via radio communication means, via BlueTooth™ radio communication, via an electrical power network, via voice recognition means, via room or temperature sensors, etc. The control system may be analogue or digital. In case the signal is not provided in a format which can be understood by the control system, a converter for converting the signal may be provided.

The control system may be operationally connected to a midi-system for creating an electronic signal representative of a piece of music. The control system may be adapted to process an electronic signal representative of music and transforming that signal into a sequence of different light colours, light intensities, and durations. Alternatively, an external control system may be provided which directly feeds the control system of the device according to the invention with a signal representing light colours, intensities and durations. A DMX-512 standard protocol may be employed for controlling the light sources. Further, the control system may be adapted to control operation of two or more devices according to the invention in such a way that the devices operate in an identical manner, i.e. in a "master-slave" fashion, or independently of one another.

As it appears from the above disclosure, the present invention also provides, in an independent aspect, a control system for controlling the colour of light escaping from a device for generating multi-coloured light, comprising:

- the control system being adapted to individually control the power fed to the first and second light source, respectively, and to supply each of said light sources with at least two power levels, whereby the colour of the light escaping from the housing may vary in accordance with the level of the power supplied to the light sources.

The control system may be programmed to, during operation of the device, always supply each of the light sources with at least a predetermined minimum power level, so that the light escaping from the housing is always obtained by a mixture of the light emitted from the at least two light sources.

Accordingly, the invention also provides a method of controlling the colour of light escaping from a device for generating multi-coloured light, comprising:

- at least a first and a second electrically powered light source for emitting light of a first, a second and a third colour, respectively,

- a housing for housing the first, second and third light sources and having at least one surface through which light emitted from said light sources may escape, the method comprising regulating the power fed to each of the light sources, and thereby changing the colour of the light emitted from the device. The method may further comprise, during operation of the device, always supplying each of the light sources with at least a predetermined minimum power level, so that the light escaping from the housing is always obtained by a mixture of the light emitted from the at least two light sources.

In a further independent aspect the invention relates to a device for generating multi- coloured light, comprising:

- at least a first, a second and a third electrically powered light source for emitting light of a first, a second and a third colour, respectively,

- a housing for housing the first, second and third light sources and having at least one surface through which light emitted from said light sources may escape, - the housing having at least one inner wall made from or coated with a material for causing light reflection, whereby light is substantially evenly distributed over at least a part of said surface through which light emitted from the light sources may escape,

- a control system for individually controlling the power fed to the first, second and third light source, respectively,

- the control system being adapted to supply each of said light sources with at least two power levels, whereby the colour of the light escaping from the housing may vary in accordance with the level of the power supplied to the light sources.

Thanks to the inner walls made from or coated with a material for causing light reflection, light is distributed evenly over at least a part of said surface through which light emitted from the light sources may escape, thereby causing a more homogeneous appearance of the device and diffuse light which homogeneously and evenly illuminates the surrounding of the device. The device according to this aspect of the invention may comprise or incorporate any or all features and functionalities discussed above in connection with the other aspects of the invention.

Brief description of the drawings

Fig. 1 is a schematic end view illustration of a first embodiment of a device according to the invention,

Fig. 2 is an illustration of a control panel incorporated in a device according to the invention,

Fig. 3 is schematic top view illustration of a second embodiment of a device according to the invention,

Fig. 4 is a schematic front view illustration of a device according to the invention.

Fig. 5 shows a possible program for a RGB-device according to the invention.

Detailed description of the drawings

Fig. 1 is a schematic end view illustration of a device 101 according to the invention. The device comprises a housing 102 which houses two sets of RGB light sources in the form of tubes 103. The housing 102 is formed with an opening at which light may escape from the device through a screen 104, such as a mesh. Along the opening and the screen 104, the housing 102 is provided with a non-transparent edge portion 102a, so as to prevent a substantial part of the light emitted by the tubes 103 from passing directly from the tubes 103 to the screen 104. The power fed to the respective RGB tubes 103 is individually controlled by a control system mounted on a control panel 105, comprising electronic components of the control system and a set of transformers 106. 5

The control panel 105 which is illustrated in Fig. 2, comprises 3 transformers, one for each colour represented in the RGB light sources 103. An electronics board 107 is further comprised in the control panel 105. The electronics board 107 comprises a power supply, a microcomputer, dimmers and power outputs for controlling the power fed to the RGB tubes 10 103.

Fig. 3 is schematic top view illustration of a second embodiment 108 of a device according to the invention. The device comprises the housing 102, RGB tubes 103, the mesh 104 and the control panel of Figs. 1 and 2. The device 108 further comprises a second screen ,104a 15 for further reflecting and thus diffusing the light escaping from the device.

Fig. 4 is a schematic front view illustration of the devices 101 and 108 of Figs. 1 and 3, respectively.

20 Fig. 5 shows a possible sequence of the power fed to each light source of a RGB-device according to the invention, respectively. Initially, all three power levels are set to their respective maximum values and after a period of time the power fed to the green and the power fed to the blue light source starts decreasing and continues decreasing until it reaches its respective minimum levels, which is seen to be larger than zero. After a stable

25 period, the power fed to the green is increased until it reaches its maximum level and after yet another stable period the power fed to the red light source starts decreasing etc.

Claims

1. A device for generating multi-coloured light, comprising:

- at least a first and a second electrically powered light source for emitting light of a first and a second colour, respectively,

- a housing for housing the first and second light sources and having at least one surface through which light emitted from said light sources may escape,

- a control system for individually controlling the power fed to the first and second light source, respectively, - the control system being adapted to supply each of said light sources with at least two power levels, whereby the colour of the light escaping from the housing may vary in accordance with the level of the power supplied to the light sources,

2. A device according to claim 1, wherein the predetermined power minimum level corresponds to 0.1 - 5% of a maximum power level which the control system may supply to the respective light sources.

3. A device according to claim 1 or 2, wherein at least a first screen is placed in the housing in such a way that at least a portion of the light emitted from the light sources is reflected by the first screen.

4. A device according to claim 3, wherein at least a second screen is placed in the housing in such a way that at least a portion of the light emitted from the light sources is reflected by the second screen.

5. A device according to claim 3, wherein the first screen comprises a first mesh.

6. A device according to claim 4, wherein the second screen comprises a second mesh.

7. A device according to claim 5 and 6, wherein the first mesh defines openings of a first size, and wherein the second mesh defines openings of a second size, the first size being different from the second size.

8. A device according to any of claims 4-7, wherein the first screen is arranged at the front of the housing and defines said surface through which light emitted from said light sources may escape, and wherein the second screen is arranged in a vertical plane between a back and a front of the housing.

5

9. A device according to any of the preceding claims, further comprising a third electrically powered light source for emitting light of a third colour.

10. A device according to any of the preceding claims, comprising a plurality of first,

10 second and optionally third light sources arranged in multiple groups of light sources, each group comprising one first, one second and optionally one third light source.

11. A device according to any of the preceding claims, wherein each of the light sources comprises a fluorescent tube selected from the group consisting of: an argon tube, a neon

15 tube, and a combined argon-neon tube.

12. A device according to any of the previous claims, wherein at least one inner wall of the housing is made from or coated with a material for causing light reflection.

20 13. A device according to any of claims 3-12, wherein at least one surface of each of the screens is made from or coated with a material for causing light reflection.

14. A device according to any of the preceding claims, wherein the housing further houses at least one transformer, at least one dimmer for individually regulating the power

25 supplied to each of the light sources, and a control system for controlling operation of the at least one dimmer.

15. A device according to claim 14, wherein the control system comprises a microcomputer which can be loaded with a computer program, the computer program being adapted to

30 load a set of data into a memory of the control system, the set of data representing power levels to be supplied to the light sources, the computer program being further adapted to cause the control system to control the power levels supplied to each of the light sources in accordance with the power levels represented by the set of data.

35 16. A device according to claim 14 or 15, wherein the control system is operable by at least one touch sensor arranged on an outer surface of the housing.

17. A device according to any of claims 14-16, wherein the control system is operable by a remote control.

18. A device according to any of claims 15-17, wherein the control system comprises an input for inputting data in the form of an electrical signal provided by an output of a sound system, and wherein the microcomputer is adapted to compute, based on said electrical

5 signal, the power levels to be supplied to the light sources.

19. A control system for controlling the colour of light escaping from a device for generating multi-coloured light, comprising:

- at least a first and a second electrically powered light source for emitting light of a first 10 and a second colour, respectively, a housing for housing the first and second light sources and having at least one surface through which light emitted from said light sources may escape,

- the control system being adapted to individually control the power fed to the first and second light source, respectively, and to supply each of said light sources with at least

15 two power levels, whereby the colour of the light escaping from the housing may vary in accordance with the level of the power supplied to the light sources,

- the control system being programmed to, during operation of the device, always supply each of the light sources with at least a predetermined minimum power level, so that the light escaping from the housing is always obtained by a mixture of the light

20 emitted from the at least two light sources.

20. A method of controlling the colour of light escaping from a device for generating multicoloured light, comprising :

- at least a first and a second electrically powered light source for emitting light of a 25 first, a second and a third colour, respectively,

- a housing for housing the first, second and third light sources and having at least one surface through which light emitted from said light sources may escape, the method comprising:

- regulating the power fed to each of the light sources, and thereby changing the colour 30 of the light emitted from the device

- during operation of the device: always supplying each of the light sources with at least a predetermined minimum power level, so that the light escaping from the housing is always obtained by a mixture of the light emitted from the at least two light sources.

35 21. A device for generating multi-coloured light, comprising: