WO2013179174A1

WO2013179174A1 - Lighting arrangement

Info

Publication number: WO2013179174A1
Application number: PCT/IB2013/054027
Authority: WO
Inventors: Maarten Marinus Johannes Wilhelmus Van Herpen; Tim Dekker
Original assignee: Koninklijke Philips N.V.
Priority date: 2012-05-29
Filing date: 2013-05-17
Publication date: 2013-12-05

Abstract

A lighting arrangement (100, 400) comprising a first light source (102, 402) configured to emit white light and for illuminating the surroundings of the lighting arrangement (100, 400) and a second light source (104, 404) configured to emit light having a predetermined color in order to combine direct light with decorative lighting. Furthermore, the lighting arrangement (100, 400) comprises a diffuser (106, 306, 406) partly covering the first and second light source and an optical element (108, 308, 408) configured to selectively direct light from the second light source (104, 404) towards at least a portion of the diffuser (106, 306, 406). The diffuser (106, 306, 406) may shine in a luminous color and the contrast of the color on the diffuser (106, 306, 406) is enhanced by the optical element (108, 308, 408) limiting the light of the second light source (104, 404) to solely the diffuser (106, 306, 406).

Description

Lighting arrangement

FIELD OF THE INVENTION

The present invention generally relates to lighting, more specifically to a lighting arrangement configured to emit both white and colored light. BACKGROUND OF THE INVENTION

Today, a lot of focus and interest is put into lighting, and lighting has become an important aspect to consider when decorating a space, such as a room. Lighting is commonly used to create a certain setting in a room or to highlight a specific item, such as a painting, apart from being used to work and read under. Furthermore, lamps are in themselves employed as objects of design and some are solely utilized to provide decorative lighting.

Due to the fast development in light sources over the recent couple of years, it is possible to procure light sources in several different colors. In addition, color adjustable light sources such as light emitting diodes combining for example red, green and blue light to achieve a color changing light source are increasingly used in for example households and in commercial settings, such color changing light sources may for example be found in

Christmas decorations.

Usually, each lamp fulfills a specific purpose in a room. For example, in a typical room there exists, in most cases, one lamp to provide for general lighting, a few reading lamps to provide focused light with higher contrast, at least one lamp in each window and on each sideboard to provide decorative lighting in different colored lights or with different colors or patterns in their lamp shades. Conventional lamps are not that versatile and in order to get both direct lighting and decorative lighting a number of lamps need to be purchased in order to decorate a room and this may amount to a significant cost.

Additionally, the number of lamps may clutter a room.

Hence, there is a need for providing a lamp that can combine these different demands into a more versatile lamp that is easily placed in different environments and that can be adjusted to fit the surroundings. SUMMARY OF THE INVENTION

In view of the above-mentioned and other drawbacks of the prior art, it is an object of the present invention to provide improvements in relation to the usability and placements light sources within a space, such as a room.

According to an aspect of the invention, the above is at least partly met by a lighting arrangement comprising a first light source arranged to illuminate the surroundings of the lighting arrangement, a second light source and a diffuser partly covering the first and second light source, wherein the lighting arrangement further comprises an optical element configured to selectively direct light from the second light source towards at least a portion of the diffuser.

The term diffuser should be understood as any type of object covering the light sources and making the light scatter and spread out in different directions when light is transmitted through the object, which reduces the perceived brightness of the light sources. The optical element should be understood as any type of filter, lens, gobo, crystal structure or optical film that may control the direction and distribution of the light. Further, it may be preferable to employ more than one second light source to illuminate the diffuser, for example when the diffuser surrounds the entire lighting arrangement in 360°.

The present invention is based on the realization that different light sources may be combined to create a more versatile lamp where a special decorative lighting effect may be combined with more direct lighting. More specifically, the inventors have realized that by limiting the directions of the light distribution from the second light source with the optical element, the illumination from the second light source may preferably be concentrated solely onto the diffuser, while white light emitted by the first light source may be unaffected by the colored light of the second light source in directions where the light does not pass the diffuser. Accordingly, by means of such a configuration it is possible to achieve a high contrast for the colored light provided on the diffuser by blocking light from the second light source transmitted in other directions than towards the diffuser through the assistance of the optical element. In addition, the brightness of the second light source may be increased to further improve the contrast of the diffuser. The first light source may be arranged to emit white light. The second light source may be arranged to emit light having a predetermined color.

Furthermore, the diffuser may be constructed as an open structure to enable light from the first light source to be transmitted to the surroundings without first passing the diffuser. Thereby, some of the light from the first light source will not be subdued by the diffuser and will maintain its brightness. Accordingly, an advantage with the present invention may be that the lighting arrangement can function simultaneously as both a lamp to work and read under, as well as for decoration lighting.

In one embodiment of the invention, the color of the light emitted by the second light source may be adjustable. The second light source may comprise any type of single or group of color adjustable light sources such as light emitting diodes in different colors that may combined and mixed to create a larger range of colors. As an example, a color adjustable light source such as a RGBW light source may create a variety of colors. Other color adjustable light sources such as RGB, RGBA, RGBAC and the like may equally well be used.

According to one embodiment of the invention, the diffuser is an open structure and the first light source at least partially illuminates the diffuser. Another part of the light may be transmitted to the surrounding of the lighting arrangement without passing the diffuser.

In one preferred embodiment of the invention, the optical element is arranged between the diffuser and the second light source. The optical element may be arranged in front of the second light source before the diffuser in relation to the direction of light, such that the optical element limits the light from the second light source to the surface of the diffuser by blocking the deviating light from the second light source. The size, shape and position of the diffuser influence the appropriate distance between the optical element and the second light source.

According to one embodiment of the invention, the optical element may be adapted to create an illumination pattern onto the diffuser. As the optical element may be used for controlling the direction and distribution of the light towards the diffuser, it is possible to allow for different decorative patterns and design configurations to be generated and displayed on the diffuser. The pattern may arise from the contrast between shadowed and illuminated areas. The patterns may be any type of pattern for example a graphical pattern comprising of stripes, circles or bar patterns.

In one embodiment of the invention, the optical element may be a gobo. A Gobo should be understood as a filter that may comprise apertures arranged over an element in such a way to generate a decorative pattern or form when placed in front of a light source. The gobo may also include differently colored areas arranged to produce a color pattern. For providing a sharp image, the gobo may be placed in the focal plane and the material of the element may preferably be temperature resistant. The gobo may also be combined with an optical system such as lenses. The gobo may be made of any type of material adapted to be arranged in front of a light source, as for example glass or metal sheets. The shapes and edges of the apertures on the gobo may direct the light from the second light source to display the shape and form of the pattern from the gobo onto the diffuser in a greater scale.

According to one embodiment of the invention, the diffuser may be a lamp shade. Furthermore, in one embodiment of the invention, the optical element may be movable in relation to the diffuser, such that light emitted from the second light source is limited to the diffuser. An advantage with the optical element being movable in relation to both the diffuser and the second light source may be that, when exchanging a diffuser with another of a different size or shape, the distance from the second light source to the optical element may be altered to adapt the shape of the light of the second light source such that light from the second light source is limited to the diffuser.

According to one embodiment of the invention, the optical element may be interchangeable. An advantage is that the decorative patterns or shapes may be conveniently exchanged and altered without having to change an entire lighting arrangement. Moreover, the lighting arrangement may further comprise a control system arranged to control the color of the light of the second light source. The color of the second light source may be continuously altered by a controller, displaying each and every color that may be mixed from the basic colored LEDs in the second light source.

In addition, an optical element and a diffuser may be combined in an incorporated arrangement, separate from the light sources, such that an appropriate optical element for a specific diffuser may be joined with the diffuser, wherein the optical element may automatically be located at a suitable distance from the specific diffuser.

Preferably, the lighting arrangement forms part of a luminaire, possibly also comprising a base structure. For example the luminaire may be provided as a table lamp, a ceiling lamp, a wall lamp or a floor lamp.

Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled person realize that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

The aspect of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which:

Fig.1 illustrates a lighting arrangement according to an embodiment of the present invention in a perspective view;

Fig. 2 illustrates an embodiment of the invention, where the optical element is a gobo;

Fig.3 illustrates a part of the lighting arrangement, where the second light source illuminates an optical element generating an illumination pattern on a diffuser; and

Fig. 4 illustrates an embodiment of the invention, where the optical element is prearranged in separate arrangement with the diffuser adapted to cover the first and second light source when assembled.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person. Like reference characters refer to like elements throughout.

In Fig. 1, there is depicted an exemplifying lighting arrangement 100 comprising a first light source 102, a second light source 104, a diffuser 106 and an optical element 108. The lighting arrangement 100 may for example be a floor lamp, a table lamp, a wall lamp, or a ceiling lamp. The lighting arrangement 100 is, in the illustrated example, stabilized and elevated by a base structure 110. In Fig 1, the first light source 102 is configured to emit white light to the surroundings, and the second light source 104 is arranged to transmit colored light directed towards the diffuser 106. The optical element 108 is provided for guiding the light from the second light source 104 to solely illuminate the diffuser 106, making the diffuser 106 color luminous. Further, the optical element may comprise a gobo, a filter, a filter with at least one opaque edges or a lens system. In the illustrated example the optical element 108 comprises two opaque ends configured to block the emitted light from the second light source 104 that is emitted in a direction not covered by the diffuser 106. Thus, the optical element 108 limits the light distribution of the second light source 104 to only illuminate the diffuser.

The diffuser 106 may be of any type of translucent material that allows for light to be transmitted through the diffuser 106 while no clear structures may be detected through the diffuser 106, including for example fabric, plastic, glass or paper, and is advantageously configured to scatter and diffuse the light transmitted through the diffuser 106. As seen from Fig. 1 , the diffuser 106 may be provided as an open structure having openings at the top and bottom in the vertical direction. The openings allow the light from the first light source 102 to be transmitted to the surroundings without passing through the diffuser 106. The diffuser 106 may be any form such as a plane surface, a cone, a cylinder or an irregular shape arranged for floor-, table or suspended lamp models. The first light source 102 may be any type of light source emitting white light, such as an incandescent light bulb, fluorescent lamps, fluorescent tubes or a combination set of light emitting diodes. Similarly, the second light source 104 may also be selected from any type of light source emitting at least one single color, such as an incandescent light bulb, fluorescent lamps, fluorescent tubes or a set of light emitting diodes. The second light source 104 is directed towards the diffuser 106 and the second light source 104 may therefore have a light distribution only directed in the forward direction. Accordingly, the lighting arrangement 100 may comprise several light sources arranged to illuminate the entire diffuser 106.

Moreover, the second light source 104 may advantageously be a color adjustable light source adapted to emit light in several colors. The color adjustable light source may comprise several light emitting diodes in different colors with the ability to mix and adjust the color by combining the light emitting diodes. Optionally, the lighting arrangement 100 may also comprise a control system (not shown) for controlling the color of the output light of the second light source 104, for example by means of a remote control or any other suitable control interface, being wired or wireless. The control system may include a microprocessor, microcontroller, programmable, digital signal processor or another programmable device. The control system may also, or instead, include an application specific integrated circuit, a programmable gate array or programmable array logic, a programmable logic device, or a digital signal processor. Where the control system includes a programmable device such as the microprocessor, microcontroller or programmable digital signal processor mentioned above, the processor may further include computer executable code that controls operation of the programmable device. Fig. 2, is illustrated by means of an alternate embodiment of the lighting arrangement 100 in Fig. 1. The lighting arrangement in Fig. 2 shows a table lamp 200 comprising a first light source which in the illustrated case is a fluorescent lamp 202. The second light source is, in this case, a color adjustable light source 204 configured to alternate between (a plurality of) different colors. Further, the diffuser is a translucent lamp shade 206 adapted to be illuminated by the color adjustable light source 204 and to diffuse the light and subdue the glare of the light from the color adjustable light source 204. Additionally, the optical element is a gobo 208 arranged to create a luminous pattern on the lamp shade 206. In this case, the gobo 208 comprises an opaque material provided with openings, such that a pattern is created, wherein the openings are configured to let light from the color adjustable light source 204 to be transmitted towards the lamp shade 206. The top and lower parts of the gobo are configured to block the stray light from the color adjustable light source 204. The gobo 206 has diagonal stripes for openings, which are configured to let the light from the color adjustable light source 204 through. Further, the shape of the gobo 208 is cylindrical allowing the entire lamp shade to display the pattern of the gobo when the entire gobo is illuminated by the color adjustable light sources 204.

In another alternative embodiment, the gobo may be a plane surface and arranged with different color transparent areas, wherein the differently colored areas may create an illumination pattern when the gobo is illuminated. In addition, the gobo may be arranged with opaque edges when the diffuser does not envelope the light sources.

Fig. 3 illustrates a part of a lighting arrangement, where a color adjustable light source 304 is arranged to emit light with different colors in the direction of a part of a diffuser 306. The optical element 308 is arranged between the color adjustable light source 304 and the diffuser 306. As seen from Fig. 3, the optical element 308 displays a pattern which is imaged onto the diffuser 306 in an enlarged scale. Patterns may be created by guiding light through a transparent medium with the shape of the a pattern surrounded by a blocking medium. Alternatively, the optical element 308 may comprise a transparent medium in addition to shapes and forms of a non-transparent material distributed over the optical element to create a desired pattern.

The diffuser 306 may be interchangeable and thus allow for the provision of other diffusers having other shapes or provided at another distance from the color adjustable light source 304. In addition, the optical element 308 is arranged to be movable in between the diffuser 306 and the color adjustable light source 304, to avoid emitting light with a color to the surroundings which not restricted by diffuser 306. When changing to a diffuser with a different size, the optical element 308 may be able to limit the light emitted from the color adjustable light source 304 to fall onto the surface of the diffuser, by moving the optical element 308 closer to or further from the diffuser. Since, moving the optical element 308 may affect the angle spread of the light.

Optionally, the pattern provided by the optical element may be dynamically adjusted, for example by arranging the optical element 308 to rotate or to move in a predetermined path. This will give rise to a dynamic lighting effect on the diffuser 306, by enabling the illumination pattern to rotate or to sweep over the diffuser 306.

Furthermore, in another embodiment an adjustable gobo may be used with the ability to alter the shape and size of the openings arranged on the gobo which enables the pattern of the diffuser to be altered. Optionally, the gobo may comprise a plurality of plates surrounding the openings. The size of the openings creating the pattern of the gobo may be changed by moving the plates further apart or closer together.

In Fig. 4, an alternative embodiment of the invention is depicted, where the lighting arrangement 400 may be separated in two parts comprising a covering unit 414 and an illumination unit 412. The illumination unit comprises a first light source 402 and a second light source 404 arranged to receive a covering unit 414 comprising of a diffuser 406 and a optical element 408. In this embodiment, the covering unit 414 is prepared with an optical element 408 adapted for that diffuser 406, where this optical element 408 is arranged such that the light from a second light source 404 only illuminates the diffuser 406 when mounted on the illumination unit 412. Thereby, the lighting arrangement 400 enables to change in-between diffusers of different shapes and sizes without the need for adjustments according to customized arrangement between the diffuser and the optical element.

Even though the invention has been described with reference to specific embodiments thereof, many different alterations, modifications and the like will become apparent for those skilled in the art. For example, the optical element may have opaque edges to restrict the light distribution from the second light source, or the optical element may comprise a lens system that limits the light distribution by refracting the light. Parts of the system may be omitted, interchanged or arranged in various ways, the system yet being able to perform the method of the present invention.

Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage.

Claims

CLAIMS:

1. A lighting arrangement (100, 400) comprising:

- a first light source (102, 402) arranged to illuminate the surroundings of the lighting arrangement (100, 400);

- a second light source (104, 404); and

- a diffuser (106, 306, 406) partly covering the first and second light source, wherein the lighting arrangement (100, 400) further comprises an optical element (108, 308, 408) configured to selectively direct light from the second light source (104, 404) towards at least a portion of the diffuser.

2. The lighting arrangement (100, 400) according to claim 1, wherein a color of the light emitted by the second light source (104, 404) is adjustable.

3. The lighting arrangement (100, 400) according to claim 1 or 2, wherein the diffuser (106, 306, 406) is an open structure and the first light source (102, 402) at most partially illuminates the diffuser (106, 306, 406).

4. The lighting arrangement (100, 400) according to any one of the preceding claims, wherein the optical element (108, 308, 408) is arranged between the diffuser (106, 306, 406) and the second light source (104, 404).

5. The lighting arrangement (100, 400) according to any one of the preceding claims, wherein the optical element (108, 308, 408) is adapted to create an illumination pattern onto the diffuser (106, 306, 406).

6. The lighting arrangement (100, 400) according to any one of the preceding claims, wherein the optical element (108, 308, 408) is a gobo (208).

7. The lighting arrangement (100, 400) according to any one of the preceding claims, wherein the diffuser (106, 306, 406) is a lamp shade (206).

8. The lighting arrangement (100, 400) according to any one of the preceding claims, wherein the optical element (108, 308, 408) is movable in relation to the diffuser (106, 306, 406), such that light emitted from the second light source (104, 404) is limited to the diffuser (106, 306, 406).

9. The lighting arrangement (100, 400) according to any one of the preceding claims, wherein the optical element (108, 308, 408) is interchangeable.

10. The lighting arrangement (100, 400) according to claim 2, further comprises a control system arranged to control the color of the light of the second light source (104, 404).

11. A luminaire comprising a lighting arrangement (100, 400) according to any one of the preceding claims.

12. The luminaire according to claim 11, further comprising a base structure (110) for receiving the lighting arrangement (100, 400).

13. The luminaire according to claim 12, wherein the luminaire is at least one of a table lamp (200), a ceiling lamp, a wall lamp or a floor lamp.