ILLUMINATION DEVICE WITH WHITE AND NON-WHITE SOURCES

Abstract

There is presented an illumination device (244) comprising a plurality of light sources (103) emitting light along an optical axis (247); a light collector (241) adapted to collect light from the light sources, wherein the plurality of light sources (103) comprises: A first group (404) of light sources comprising a plurality of light sources, which can be driven to emit white light, a second group (405) of light sources comprising a plurality of light sources which can be driven, such as can only be driven, to emit non-white light (such as green light), wherein the plurality of light sources can be driven so that a total D.sub.uv value of light emitted from the illumination device is closer to zero than each of a first D.sub.uv value of light emitted from the illumination device originating from the first group (404) of light sources and a second D.sub.uv value of light emitted form the illumination device originating from the second group (405) of light sources, and a luminous efficacy of the second group (405) of light sources is higher than a luminous efficacy of the first group (404) of light sources.

Claims

1. An illumination device comprising: a plurality of light sources emitting light along an optical axis; and a light collector adapted to collect light from the plurality of light sources and adapted to project at least a part of said light along said optical axis, wherein the plurality of light sources comprises: a first group of light sources comprising a plurality of light sources, which can be driven to emit white light, and a second group of light sources comprising a plurality of light sources which can be driven to emit non-white light, wherein the plurality of light sources can be driven so that: a total D.sub.uv value of light emitted from the illumination device is closer to zero than each of a first D.sub.uv value of light emitted from the illumination device originating from the first group of light sources and a second D.sub.uv value of light emitted from the illumination device originating from the second group of light sources, and a luminous efficacy of the second group of light sources is higher than a luminous efficacy of the first group of light sources.

2. The illumination device according to claim 1, wherein each of the plurality of light sources in the first group of light sources be driven to emit light having a negative D.sub.uv value.

3. The illumination device according to claim 1, wherein each of the plurality of light sources in the second group of light sources can be driven to emit light having a positive D.sub.uv value.

4. The illumination device according to claim 1, wherein the first group of light sources and the second group of light sources can be driven to have D.sub.uv values of opposite sign with respect to each other.

5. The illumination device according to claim 1, wherein each of the plurality of light sources in the second group of light sources can be driven to emit green light.

6. The illumination device according to claim 1, wherein a ratio of intensities of light emitted from the first group of light sources and light emitted from the second group of light sources is substantially fixed.

7. The illumination device according to claim 1, wherein a ratio of intensities of light emitted from the first group of light sources and light emitted from the second group of light sources can be controlled.

8. The illumination device according to claim 1, wherein one or more light sources within the second group of light sources are placed between light sources within the first group of light sources in a tangential and/or a radial direction with respect to the optical axis.

9. The illumination device according to claim 1, wherein one or more light sources placed most distantly with respect to the optical axis are within the first group of light sources.

10. (canceled)

11. The illumination device according to claim 1, wherein white light emitted from the illumination device is light having a D.sub.uv value in an interval [−0.015; +0.015] and a Correlated Colour Temperature (CCT) in an interval [2600 K; 9500 K].

12. The illumination device according to claim 1, wherein the illumination device can be driven to emit a total D.sub.uv value of light in an interval [−0.015; +0.015].

13. The illumination device according to claim 1, wherein a number of light sources within the first group of light sources is 2 or more times higher than a number of light sources within the second group of light sources.

14. The illumination device according to claim 1, wherein the first group of light sources and the second group of light sources are kept in separate strings.

15. (canceled)

16. The illumination device according to claim 1, wherein each light source in the second group of light sources comprises a ceramic converter for wavelength conversion.

17. (canceled)

18. The illumination device according to claim 1, wherein: an illuminance of the first group of light sources can be driven above 350 lm/mm.sup.2 for an effective light emitting surface; or an illuminance of the second group of light sources can be driven above 250 lm/mm.sup.2.

19. (canceled)

20. The illumination device according to claim 1, wherein a luminous efficacy of the second group of light sources is at least 15% higher than a luminous efficacy for the first group of light sources.

21. The illumination device according to claim 1, wherein the light collector comprises a plurality of lenslets adapted to collect light from the plurality of light sources and adapted to convert the collected light into a plurality of light beams so that the light beams propagate along said optical axis, where each of said lenslets comprises an entrance surface where the light enters the lenslet and an exit surface where the light exits the lenslet.

22. The illumination device according to claim 1, further comprising one or more color filters.

23-24. (canceled)

25. The illumination device according to claim 1, wherein the illumination device is capable of delivering at least 10 klm.

26. The illumination device according to claim 1, further comprising an optical gate arranged along the optical axis and wherein the light collector is arranged between said plurality of light sources and said optical gate.

27-34. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The first, second, third and fourth aspect according to the invention will now be described in more detail with regard to the accompanying figures. The figures show one way of implementing the present invention and is not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.

[0067] FIG. 1 shows the CIE 1931 color space.

[0068] FIG. 2 shows a light fixture 200 comprising an illumination device 244.

[0069] FIG. 3 illustrates a structural diagram of a moving head light fixture 302.

[0070] FIG. 4 shows a layout of LEDs 103 as viewed in a direction along the optical axis 247.

DETAILED DESCRIPTION

[0071] FIG. 1 shows the CIE 1931 color space, wherein the black body line (BBL), also know as the black body curve/locus or the Planckian locus, is shown as the curved line with the full circle markers. Colour coordinates light emitted from the first group of light sources at low intensity may in an exemplary embodiment be given as indicated by the star at approximately (x; y)=(0.525; 0.425) (where the actual distance from the black body line might be exaggerated for clarity). At increasing intensity, the colour coordinate may become magenta shifted as indicated by the downward (and left) pointing arrow between the star and the triangle, and end up at the triangle. By adding light from the second group of light sources, which in itself might have a color coordinate as indicated by the rectangle at around (x; y)=(0.32; 0.64) it might be possible to shift the total color coordinate from the triangle along the dotted line between the triangle and the rectangle in a direction towards the rectangle as indicated by the upward pointing arrow. The figure furthermore shows areas in the color space bounded by dashed lines, which defines green light according to embodiments, such as light having coordinates in the CIE 1931 color space falling within an area bounded by (a) the black body line, (b) a line between the achromatic point (as indicated by the pentagon), such as (x; y)=(1/3; 1/3), and a monochromatic point (on the edge of the visible area) with wavelength 490 nm, and (c) a line between the achromatic point and a monochromatic point with wavelength 570 nm and excluding white light, such as excluding light having a positive value of equal to or less than 0.015.

[0072] FIG. 2 shows a light fixture 200 comprising an illumination device 244, wherein the illumination device comprises a plurality of LEDs 103, a light collector 241, an optical gate 242 and an optical projecting and zoom system 243. The light collector 241 is adapted to collect light from the LEDs 103 and to convert the collected light into a plurality of light beams 245 (dotted lines) propagating along an optical axis 247 (dash-dotted line). The light collector can be embodied as any optical means capable of collecting at least a part of the light emitted by the LEDs and convert the collected light to light beams. In the illustrated embodiment the light collector comprises a number of lenslets each collecting light from one of the LEDs and converting the light into a corresponding light beam. However it is noticed that the light collector also can be embodied as a single optical lens, a Fresnel lens, a number of TIR lenses (total reflection lenses), a number of light rods or combinations thereof. It is understood that light beams propagating along the optical axis contain rays of light propagating at an angle, e.g. an angle less that 45 degrees to the optical axis. The light collector may be configured to fill the optical the gate 242 with light from the light sources 103 so that the area, i.e. the aperture, of the gate 242 is illuminated with a uniform intensity or optimized for max output. The gate 242 is arranged along the optical axis 247. The optical projecting system 243 may be configured to collect at least a part of the light beams transmitted through the gate 242 and to image the optical gate at a distance along the optical axis. For example, the optical projecting system 243 may be configured to image the gate 242 onto some object such as a screen, e.g. a screen on a concert stage. A certain image, e.g. some opaque pattern provided on a transparent window, an open pattern in a non-transparent material, or imaging object such as GOBOs known in the field of entertainment lighting, may be contained within the gate 242 so that that the illuminated image can be imaged by the optical projecting system. Accordingly, the illumination device 200 may be used for entertainment lighting. In the illustrated embodiment the light is directed along the optical axis 247 by the light collector 241 and passes through a number of light effects before exiting the illumination device through a front lens 243a. The light effects can for instance be any light effects known in the art of intelligent/entertainments lighting for instance, a CMY color mixing system 251, color filters 253, gobos 255, animation effects 257, iris effects 259, a focus lens group 243c, zoom lens group 243b, prism effect 261, framing effects (not shown), or any other light effects known in the art. The mentioned light effects only serves to illustrate the principles of an illuminating device for entertainment lighting and the person skilled in the art of entertainment lighting will be able to construct other variations with additional are less light effects. Further it is noticed that the order and positions of the light effects can be changed. The illumination device comprises a cooling module 201 with first 115 and second 117 blowers. The light fixture comprises a lamp housing 248 provided with a number of openings 250.

[0073] FIG. 3 illustrates a structural diagram of a moving head light fixture 302 comprising a head 200 rotatably connected to a yoke 363 where the yoke is rotatably connected to a base 365. The head is substantially identical to the light fixture shown in FIG. 2 and substantial identical features are labeled with the same reference numbers as in FIG. 2 will not be described further. The moving head light fixture comprises pan rotating means for rotating the yoke in relation to the base, for instance by rotating a pan shaft 367 connected to the yoke and arranged in a bearing (not shown) in the base). A pan motor 369 is connected to the shaft 367 through a pan belt 371 and is configured to rotate the shaft and yoke in relation to the base through the pan belt. The moving head light fixture comprises tilt rotating means for rotating the head in relation to the yoke, for instance by rotating a tilt shaft 373 connected to the head and arranged in a bearing (not shown) in the yoke). A tilt motor 375 is connected to the tilt shaft 373 through a tilt belt 377 and is configured to rotate the shaft and head in relation to the yoke through the tilt belt. The skilled person will realize that the pan and tilt rotation means can be constructed in many different ways using mechanical components such as motors, shafts, gears, cables, chains, transmission systems, bearings etc. Alternatively it is noticed that it also is possible to arrange the pan motor in the base and/or arrange the tilt motor in the head. The space between the yoke 363 and the bottom part of the head is limited as the moving head light fixture is designed to be as small as possible. As known in the prior art the moving head light fixture receives electrical power 381 from an external power supply (not shown). The electrical power is received by an internal power supply 383 which adapts and distributes electrical power through internal power lines (not shown) to the subsystems of the moving head. The internal power system can be constructed in many different ways for instance by connecting all subsystems to the same power line. The skilled person will however realize that some of the subsystems in the moving head need different kind of power and that a ground line also can be used. The light source will for instance in most applications need a different kind of power than step motors and driver circuits. The light fixture comprises also a controller 385 which controls the components (other subsystems) in the light fixture based on an input signal 387 indicative light effect parameters, position parameters and other parameters related to the moving head lighting fixture. The controller receives the input signal from a light controller (not shown) as known in the art of intelligent and entertainment lighting for instance by using a standard protocol like DMX, ArtNET, RDM etc. Typically the light effect parameter is indicative of at least one light effect parameter related to the different light effects in the light system. The controller 385 is adapted to send commands and instructions to the different subsystems of the moving head through internal communication lines (not shown). The internal communication system can be based on a various type of communications networks/systems. The moving head can also comprise user input means enabling a user to interact directly with the moving head instead of using a light controller to communicate with the moving head. The user input means 389 can for instance be bottoms, joysticks, touch pads, keyboard, mouse etc. The user input means can also be supported by a display 391 enabling the user to interact with the moving head through a menu system shown on the display using the user input means. The display device and user input means can in one embodiment also be integrated as a touch screen.

[0074] FIG. 4 shows a layout of LEDs 103 as viewed in a direction along the optical axis 247, e.g., in a direction from the gate 242 towards the LEDs 103. The first group 404 of LEDs are shown with open structure and the second group 405 of LEDs are shown with closed (black) structure). Light sources within the second group of light sources are placed between light sources within the first group of light sources in a tangential and a radial direction with respect to the optical axis (which is in the center of the circular pattern and oriented orthogonal to the plane of the paper). An average (such as a geometrical average and an intensity weighted average) position of each of the first group of light sources and the second group of light sources is at the optical axis. The light sources placed most distantly with respect to the optical axis are within the first group of light sources.

[0075] The first group of light sources may for example comprise, such as consist of LEDs from OSRAM Opto Semiconductors GmbH (Regensburg, Germany) of type KW CSLNM1.TG and/or LEDs with characteristics as described in the corresponding product sheet (retrieveable, e.g., at https://www.osram-os.com/) denoted “Version 1.2” and dated 2018 May 7.

[0076] The second group of light sources may for example comprise, such as consist of LEDs from OSRAM Opto Semiconductors GmbH (Regensburg, Germany) of type KP CSLNM1.F1 and/or LEDs with characteristics as described in the corresponding product sheet (retrieveable, e.g., at https://www.osram-os.com/) denoted “Version 1.6” and dated 2018 Apr. 25.

[0077] Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is set out by the accompanying claim set. In the context of the claims, the terms “comprising” or “comprises” do not exclude other possible elements or steps. Also, the mentioning of references such as “a” or “an” etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous.