WO2012110908A1

WO2012110908A1 - A luminaire comprising a fixture and at least one lighting element, as well as such a fixture

Info

Publication number: WO2012110908A1
Application number: PCT/IB2012/050483
Authority: WO
Inventors: Alexander Cornelis GEERLINGS; Martine Gabrielle Pythia Van Beers; Henk Albert DAMMER
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2011-02-18
Filing date: 2012-02-02
Publication date: 2012-08-23

Abstract

A luminaire (1, 21, 31, 41, 51) comprises a fixture (2, 22, 32, 42, 52) and at least one lighting element (29). The fixture (2, 22, 32, 42, 52) is suspendible from a ceiling above a working area, wherein, in use, a side of the fixture (2, 22, 32, 42, 52) is directed towards the working area. On said side of the fixture (2, 22, 32, 42, 52),the fixture (2, 22, 32, 42, 52) comprises a sound reflecting element at least near a central region of the fixture (2, 22, 32, 42, 52) and a sound absorbing element (6, 26, 36, 46, 56) at least near the periphery (5, 25, 35, 45, 55) of the fixture (2, 22,32, 42, 52). Projected on the working area, the surface of the sound reflecting element is in the range of 40 to 80 percent of the total projected surface of the fixture on the working area, whilst the surface of the sound absorbing element (6, 26, 36, 46, 56) is in the range of 60 to 20 percent of the total projected surface of the fixture on the working area.

Description

A LUMINAIRE COMPRISING A FIXTURE AND AT LEAST ONE LIGHTING ELEMENT, AS WELL AS SUCH A FIXTURE

FIELD OF THE INVENTION

The invention relates to a luminaire comprising a fixture and at least one lighting element, which fixture is suspendible from a ceiling above a working area, wherein, in use, a side of the fixture is directed towards the working area.

The invention also relates to a fixture.

BACKGROUND OF THE INVENTION

Luminaires which are suspended from a ceiling above an area to be illuminated are well known in the art in all kinds of shapes. They are used in living rooms, bedrooms etc. of housings. In offices, suspended luminaires are used less frequently. In offices it is more common to use lighting mounted in the ceiling to illuminate the whole office.

In open-space office environments, there is an increasing demand to create locally a workspace where a limited number of persons can meet and discuss topics. The requirements to be fulfilled by such a local workspace are that the members of the meeting can speak freely with each other without disturbing other persons in the office and without being overheard by other persons in the office. However, if the noise level in the office is relatively high, the members of the meeting will tend to increase the intensity of their voice to enhance its audibility, thereby disturbing other persons in the office or being overheard by other persons in the office.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a luminaire to illuminate a working area, which luminaire has improved acoustics, so that persons present in the working area can meet and discuss topics with each other at a lower voice without loss of audibility to the other persons present in the working area. This object is achieved by the luminaire according to the invention, in that on said side of the fixture, the fixture comprises a sound reflecting element at least near a central region of the fixture and a sound absorbing element at least near the periphery of the fixture. The luminaire can for example be suspended from a ceiling in an office and may be located above a conference table around which people may sit or stand. When persons gathering in a relatively large open office are standing or sitting below the luminaire, the sound reflecting element improves the audio of the speaker for the other persons in the meeting. The sound absorbing element near or on the periphery of the fixture prevents early reflections of speech sounds towards the speaker himself, which reflections would be annoying to the speaker. Due to the improved acoustics in the working area below the luminaire, the persons attending the meeting will lower their voices without loss of audibility. Noise pollution to the rest of the office will be reduced, so they will not, or to a lesser degree, disturb or be overheard by other persons in the office. An embodiment of the luminaire according to the invention is characterized in that, projected on the working area, the surface of the sound reflecting element is in the range of 40 to 80 percent of the total projected surface of the fixture on the working area, whilst the surface of the sound absorbing element is in the range of 60 to 20 percent of the total projected surface of the fixture on the working area. It has been found that these percentages of the surfaces of the sound reflecting element and sound absorbing element yield a good balance between improving the audibility of the speaker and avoiding early speech reflections towards the speaker or persons close to the speaker .

Another embodiment of the luminaire according to the invention is characterized in that the sound reflecting element and the sound absorbing element are reflective and absorbent, respectively, for speech relevant frequencies in the range of 200 Hz to 7000 Hz. Since the luminaire is to be used above a working area where people can meet and speak to each other, the sound reflecting element and the sound absorbing element should at least reflect and absorb, respectively, these frequencies.

A further embodiment of the luminaire according to the invention is characterized in that, in use, at least two persons facing each other can be present in the virtual cylinder bounded by the periphery of the fixture and the projection thereof on the working area, wherein, when a first person speaks to the second person, the sound of the speech is partly absorbed by a part of the sound absorbing element near the first person and partly reflected by the sound reflecting element towards the second person. The luminaire needs to be so large that at least two persons, but preferably a larger number of persons, for example 6 to 12 persons, can be accommodated in the virtual cylinder. The virtual cylinder can have any cross section like circular, oval, elliptical, square, rectangular, organic, etc... If the periphery of the fixture has a circular shape, the diameter of the circle will be at least 1 metre, but preferably in the range of 1.5 meter to 3 meter.

The persons may, however, also be present outside the virtual cylinder and still be part of the meeting. The required sound absorbing and sound reflecting properties of the fixture will work as long as the heads of the persons are within a preferred distance of about 0.5 - 1 meter from the periphery of the fixture. Yet another embodiment of the luminaire according to the invention is characterized in that the fixture itself forms at least part of the sound reflecting element.

In said embodiment, a separate sound reflecting element can be dispensed with.

Another embodiment of the luminaire according to the invention is characterized in that the sound reflecting element is concave shaped. In the case of such a concave shaped or dome shaped sound reflecting element, a focus will be created on a side of the working area opposite to the speaker.

Another embodiment of the luminaire according to the invention is characterized in that the sound reflecting element extends substantially horizontally. Such a flat reflector favours acoustic reflections towards a side of the working area opposite to the speaker.

Another embodiment of the luminaire according to the invention is characterized in that the sound absorbing element fixture is ring-shaped.

Because the sound absorbing element has the shape of a ring, the person speaking can stand anywhere under the luminaire, and early reflections of his voice will be absorbed by the part of the sound absorbing element closest to him.

Another embodiment of the luminaire according to the invention is characterized in that an air gap is located between the fixture and the sound absorbing element.

Due to the air gap the absorption performance of the sound absorbing element will be broadened towards lower frequencies.

Another embodiment of the luminaire according to the invention is characterized in that the luminaire comprises a light diffuser, wherein the lighting element is located between the sound reflecting element and the light diffuser.

The light diffuser will create a diffused lighting effect for the working area, which will improve the atmosphere and enhance the feeling of being a member of a team for the persons in the meeting. Another embodiment of the luminaire according to the invention is characterized in that the light diffuser has a relatively low density to be transparent to speech relevant frequencies.

In this manner, the voices will only be reflected by the sound reflecting element, whose shape and size can be optimized for this acoustic function, whilst the light diffuser can be optimized for its light diffusing function.

The invention also relates to a fixture that is suspendible from a ceiling above a working area, wherein, in use, a side of the fixture is directed towards the working area, whilst on said side of the fixture, the fixture comprises a sound reflecting element at least near a central region of the fixture and a sound absorbing element at least near the periphery of the fixture.

Such a fixture can be used as a fixture for a luminaire but can also be used without lighting elements. In the latter case, the fixture is used to improve the acoustics in a working area. It has to be noted that US 6,202,361 B l discloses an acoustic dome having a diameter smaller than the table above which it is suspended. Persons standing around the table will not be located under the dome. The dome has an inner shell with a downward facing smooth side to reflect sound generated at or near the working area towards the working area. However, since the whole inner shell is made of sound reflecting material, a speaker will get annoyed by early reflections of the speech sounds to the speaker himself.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail with reference to the drawings, in which

Fig. 1A, IB and 1C are a perspective view, a cross sectional view and a bottom view, respectively, of a luminaire according to a first embodiment of the invention, Fig. 2A, 2B and 2C are a perspective view, a cross sectional view and a bottom view, respectively, of a luminaire according to a second embodiment of the invention,

Fig. 3 A, 3B and 3 C are a perspective view, a cross sectional view and a bottom view, respectively, of a luminaire according to a third embodiment of the invention, Fig. 4A, 4B and 4C are a perspective view, a cross sectional view and a bottom view, respectively, of a luminaire according to a fourth embodiment of the invention,

Fig. 5A, 5B and 5C are a perspective view, a cross sectional view and a bottom view, respectively, of a luminaire according to a fifth embodiment of the invention.

Like parts are indicated by the same reference numbers in the figures. DETAILED DESCRIPTION OF EMBODIMENTS

Fig. 1A, IB and 1 C are different views of a luminaire 1 according to a first embodiment of the invention. The luminaire 1 comprises a rounded triangular dome- shaped fixture 2. The fixture is made of sound reflecting material like fiberglass. By means of a cable 3, the fixture 2 is suspended from a ceiling 4 above a working area. A virtual cylinder 5 ' is bounded by the periphery 5 of the fixture 2 and the projection thereof on the working area. The fixture 2 comprises a ring-shaped sound absorbing element 6 located on a side of the fixture 2 directed towards the working area and near the periphery 5 of the fixture 2. The sound absorbing element 6 is made of sound absorbing material. An absorbing material is a substantially open pore material which, for example, can be obtained by using open pore foam such as PU foam, a packing of fibres such as glass wool or even a basically reflective material with many perforations. Sound is absorbed by pressure fluctuations in these pores. The sound absorbing element 6 can be covered with a relatively thin layer of a dense material for design reasons. This thin layer will have no or nearly no effect on the sound absorbing properties of the sound absorbing element 6. Due to the ring-shaped sound absorbing element 6 located in front of the fixture 2, only the central region of the fixture 2 will act as a sound reflecting element. Projected on the working area, the surface of the sound reflecting element is in the range of 40 to 80 percent, whilst the surface of the sound absorbing element 6 is in the range of 60 to 20 percent. The sound reflecting element and the sound absorbing element 6 are reflective and absorbent, respectively, for speech relevant frequencies in the range of 200 Hz to 7000 Hz. The absorption by the sound absorbing element 6 will be at least 20% and preferably even more. With a radius of the fixture of about 1.5 meter, the sound absorbing element 6 may have a width of about 0.2 meter.

The luminaire 1 comprises a circular light diffuser 7. The light diffuser 7 is located inside the ring shaped sound absorbing element 6, thereby hiding the central region of the fixture 2 from view. The lighting element (not shown) is located between the sound reflecting element formed by the fixture 2 and the light diffuser 7. Preferably, the light diffuser 7 has a relatively low density to be transparent to speech relevant frequencies, so that sound directed from the working area to the luminaire 2 will either be absorbed by the sound absorbing element 6 or reflected by the sound reflecting material of the central region of the fixture 2.

The size of the fixture 2 is such that a predetermined number of persons, for example 2 or 10, can sit or stand in or near the virtual cylinder 5 ' to speak to each other. In the vicinity of the first person who is speaking, the sound of the speech is absorbed by a part of the sound absorbing element 6. However, the other persons will clearly hear the first person since his speech will be reflected towards them by the sound reflecting element.

The side of the fixture 2 directed towards the ceiling 3 can be made of or provided with any kind of material. However, preferably at least one material is chosen which prevents acoustics to travel from above through the fixture 2 towards the working area. Fig. 2A, 2B and 2C are different views of a luminaire 21 according to a second embodiment of the invention. The luminaire 21 comprises a cone shaped fixture 22. The fixture 22 is suspended from a ceiling above a working area by means of cable 23. A virtual cylinder 25 ' is bounded by the periphery 25 of the fixture 22 and the projection thereof on the working area. In the fixture 22 a sound reflecting element 28 is located. The fixture 22 comprises a ring-shaped sound absorbing element 26 located on a side of the fixture 22 directed towards the working area and on the periphery 25 of the fixture 22. Due to the ring-shaped sound absorbing element 26 located in front of the sound reflecting element 28, only the central region of the sound reflecting element 28 will be able to reflect sounds. The other part of the sound reflecting element 28 located between the fixture 22 and the sound absorbing element 26 will only be used as part of the design and the mechanical structure. The luminaire 21 comprises a circular light diffuser 27. The light diffuser 27 is located inside the ring shaped sound absorbing element 26, thereby hiding the sound reflecting element 28 from view. The lighting element 29, a circular fluorescent lamp, is located between the sound reflecting element 28 and the light diffuser 27. Preferably, the light diffuser 27 has a relatively low density to be transparent to speech relevant frequencies, so that sound directed from the working area to the luminaire 22 will either be absorbed by the sound absorbing element 26 or reflected by the sound reflecting element 28.

Fig. 3A, 3B and 3C are different views of a luminaire 31 according to a third embodiment of the invention. The luminaire 31 comprises a concave, rounded, square shaped fixture 32. The fixture 32 is suspended from a ceiling above a working area by means of cables 33. The fixture 32 itself forms the sound reflecting element. The fixture 32 comprises a ring-shaped sound absorbing element 36 located on a side of the fixture 32 directed towards the working area and adjacent the periphery 35 of the fixture 32. Due to the ring-shaped sound absorbing element 36 located in front of the fixture 32, only the central region of the fixture 32 will be able to reflect sounds. The luminaire 31 comprises a circular light diffuser 37. The light diffuser 37 is located inside the ring shaped sound absorbing element 36, thereby hiding the fixture 32 from view. The lighting element (not shown) is located between the fixture 32 and the light diffuser 37. Preferably, the light diffuser 37 has a relatively low density to be transparent to speech relevant frequencies, so that sound directed from the working area to the luminaire 32 will either be absorbed by the sound absorbing element 36 or reflected by the central portion of the fixture 32. Fig. 4A, 4B and 4C are different views of a luminaire 41 according to a fourth embodiment of the invention. The luminaire 41 comprises a concave, circular fixture 42. The fixture 42 itself forms the sound reflecting element. The fixture 42 comprises a ring- shaped sound absorbing element 46 located on a side of the fixture 42 directed towards the working area and near the periphery 45 of the fixture 42. The luminaire 41 comprises a circular light diffuser 47 located inside the ring shaped sound absorbing element 46.

Fig. 5A, 5B and 5C are different views of a luminaire 51 according to a fifth embodiment of the invention. The luminaire 51 comprises a concave, circular fixture 52 with a number of horizontally extending ring shaped parts 59 and a centrally located circular part 60. The fixture 52 itself forms the sound reflecting element. The fixture 52 comprises a ring-shaped sound absorbing element 56 located on a side of the fixture 52 directed towards the working area and near the periphery 55 of the fixture 52. The luminaire 51 comprises a circular light diffuser 57 located inside the ring shaped sound absorbing element 56. It is also possible that an air gap is located between the fixture and the sound absorbing element to enhance the sound absorbing properties at and/or near the periphery of the fixture.

It is also possible to use a relatively small light diffuser or no light diffuser at all.

The fixture can be sized such that it can be suitably located above a working area provided for example with a conference table to improve the acoustics at the working area.

It is also possible to use as a lighting element, for example, a plurality of LEDs or a high intensity discharge lamp.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practising 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. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A luminaire (1, 21, 31, 41, 51) comprising a fixture (2, 22, 32, 42, 52) and at least one lighting element (29), which fixture (2, 22, 32, 42, 52) is suspendible from a ceiling (4) above a working area, wherein, in use, a side of the fixture (2, 22, 32, 42, 52) is directed towards the working area, characterized in that on said side of the fixture (2, 22, 32, 42, 52), the fixture (2, 22, 32, 42, 52) comprises a sound reflecting element at least near a central region of the fixture (2, 22, 32, 42, 52) and a sound absorbing element (6, 26, 36, 46, 56) at least near the periphery (5, 25, 35, 45, 55) of the fixture (2, 22, 32, 42, 52).

2. A luminaire (1, 21, 31, 41, 51) according to claim 1, characterized in that, projected on the working area, the surface of the sound reflecting element is in the range of 40 to 80 percent of the total projected surface of the fixture on the working area, whilst the surface of the sound absorbing element (6, 26, 36, 46, 56) is in the range of 60 to 20 percent of the total projected surface of the fixture on the working area.

3. A luminaire (1, 21, 31, 41, 51) according to claim 1 or 2, characterized in that the sound reflecting element and the sound absorbing element (6, 26, 36, 46, 56) are reflective and absorbent, respectively, for speech relevant frequencies in the range of 200 Hz to 7000 Hz.

4. A luminaire (1, 21, 31, 41, 51) according to any one of the preceding claims, characterized in that, in use, at least two persons facing each other can be present in the virtual cylinder (5 ', 25') bounded by the periphery (5, 25, 35, 45, 55) of the fixture (2, 22, 32, 42, 52) and the projection thereof on the working area, wherein, when a first person speaks to the second person, the sound of the speech is partly absorbed by a part of the sound absorbing element (6, 26, 36, 46, 56) near the first person and partly reflected towards the second person by the sound reflecting element.

5. A luminaire (1, 21, 31, 41, 51) according to any one of the preceding claims, characterized in that the fixture (2, 22, 32, 42, 52) itself forms at least part of the sound reflecting element.

6. A luminaire (1, 21, 31, 41, 51) according to any one of the preceding claims, characterized in that the sound reflecting element is concave shaped.

7. A luminaire (1, 21, 31, 41, 51) according to any one of the preceding claims 1 to 5, characterized in that the sound reflecting element extends substantially horizontally.

8. A luminaire (1, 21, 31, 41, 51) according to any one of the preceding claims, characterized in that the sound absorbing element (6, 26, 36, 46, 56) is ring-shaped.

9. A luminaire (1, 21, 31, 41, 51) according to any one of the preceding claims, characterized in that an air gap is located between the fixture (2, 22, 32, 42, 52) and the sound absorbing element (6, 26, 36, 46, 56).

10. A luminaire (1, 21, 31, 41, 51) according to any one of the preceding claims, characterized in that the luminaire (1, 21, 31, 41, 51) comprises a light diffuser, wherein the lighting element (29) is located between the sound reflecting element and the light diffuser.

11. A luminaire (1, 21, 31, 41, 51) according to claim 10, characterized in that the light diffuser has a relatively low density to be transparent to speech relevant frequencies.

12. A fixture (2, 22, 32, 42, 52) according to any one of the preceding claims, which fixture (2, 22, 32, 42, 52) is suspendible from a ceiling above a working area, wherein, in use, a side of the fixture (2, 22, 32, 42, 52) is directed towards the working area, whilst on said side of the fixture (2, 22, 32, 42, 52), the fixture (2, 22, 32, 42, 52) comprises a sound reflecting element at least near a central region of the fixture (2, 22, 32, 42, 52) and a sound absorbing element (6, 26, 36, 46, 56) at least near the periphery (5, 25, 35, 45, 55) of the fixture (2, 22, 32, 42, 52).