A rotatable tubular luminair

Abstract

The present invention relates to a luminaire (1) for providing luminaire light (6), the luminaire having a rotation axis (RA) and comprising: - a tubular housing (2) extending along the rotation axis and comprising a compartment (3) enclosed by a wall portion (4) and a light-transmissive light exit window (5); - a LED light source (7) configured to emit LED light and being accommodated in the compartment (3); - a stand (8) which carries the tubular housing, wherein the tubular housing (2) and the stand are rotatable with respect to each other over a rotation angle (θ) around the rotation axis; and - wherein the light exit window (5) is configured to transmit the LED light as the luminaire light (6), and wherein the light exit window has an opening angle (α) in a cross-section perpendicular to the rotation axis, which opening angle (α) varies in dependency on the rotation angle (θ).

Description

[0001] A ROTATABLE TUBULAR LUMINAIR

[0002] TECHNICAL FIELD

[0003] The present invention relates to a rotatable tubular luminaire providing a luminaire light having a beam angle that varies dependent on the rotation angle. Further, the present invention relates to a method for controlling such a luminaire.

[0004] BACKGROUND

[0005] Setting a correct light in an interior environment is of large importance. First of all, a correctly illuminated room is perceived by the user as attractive and pleasant to reside. Thus, in an industrial site or in a workshop, the light setting may be used for providing conditions in which the operators have a clear view of objects that they are working on. This is particularly important when objects comprise small parts to be assembled, or when the operator has to perform the work in an obstructed environment, such as under a vehicle or the like. In a home environment, it may be desirable to adapt the lighting conditions to the activity of subjects residing a room.

[0006] A lighting system used in an interior environment should be highly adaptable, giving the user possibility to control different parts of the lighting system independently, such that the light setting may be adapted to a current situation.

[0007] Currently, tubular luminaires has emerged as a versatile lighting device. Such luminaires have a possibility to provide highly adaptable and decorative lighting. However, there is a need to improve decorative lighting effect of tubular luminaires.

[0008] SUMMARY OF THE INVENTION

[0009] Considering the above, the object of the present invention is to provide such a luminaire. To this end, the present invention provides a luminaire for providing luminaire light, the luminaire having a rotation axis (RA). The rotation axis may coincide with a longitudinal axis of the luminaire. The extension of the luminaire along of the longitudinal axis depends on the intended application, and may be from 10 cm to 5 m.

[0010] The luminaire according to the present invention further comprises a tubular housing extending along the rotation axis and comprising a compartment enclosed by a wall portion and a light-transmissive light exit window. The tubular housing may be arranged such that it delimits an inner compartment and has an inner surface facing the inner compartment and an outer surface facing away from the inner compartment. The wall portion and the light exit window may form a closed tubular structure.

[0011] The luminaire further comprises a LED light source configured to emit LED light and being accommodated in the compartment. The light exit window is configured to transmit the LED light as the luminaire light. The LED light source may be arranged on the inner surface of the wall portion. Alternatively, the LED light source may be arranged elsewhere inside the inner compartment of the luminaire.

[0012] The LED light source may comprise a plurality of red LEDs configured to emit in operation red LED light, a plurality of green LEDs configured to emit in operation green LED light, a plurality of blue LEDs configured to emit in operation blue LED light, and a plurality of white LEDs configured to emit in operation white LED light having a correlated color temperature in a range from 2000K to 6500K and a CRI of at least 80. The plurality of red, green, blue and white LEDs may be arranged in an array extending along the rotation axis. The luminaire may further comprise a control unit configured to individually control the red light emitted by the plurality of red LEDs, the green light emitted by the plurality of green LEDs, the blue light emitted by the plurality of blue LEDs, and the white light emitted by the plurality of white LEDs. According to the present invention, gradients in colors and / or correlated color temperatures can be obtained.

[0013] The luminaire further comprises a stand which carries the tubular housing. The tubular housing and the stand are rotatable with respect to each other over a rotation angle (9) around the rotation axis. The term “rotatable” in the context of the present invention implies to move in such a way that all particles follow circles with a common angular velocity about a common axis.

[0014] According to the present invention, the light exit window has an opening angle (a) in a cross-section perpendicular to the rotation axis, which opening angle (a) varies in dependency on the rotation angle (9).

[0015] The rotation axis may be centrally or non-centrally arranged with respect to the stand and / or tubular housing.

[0016] The light exit window may have a first opening angle (al) when the tubular housing and the stand are in a first mutual rotation position (Ml). In such a configuration, the luminaire light is emitted in a first direction (DI). The first direction DI may be the direction towards a surface being adjacent to the luminaire. The surface being adjacent to a luminaire may be a surface to which the luminaire is attached, or a surface in proximity of the luminaire, e.g. a wall.

[0017] Further, the light exit window may have a second opening angle (a2) when the tubular housing and the stand are in a second mutual rotation position (M2) different from the first mutual rotation position (Ml). In such a configuration, the luminaire light may be emitted in a second direction (D2) opposite to the first direction. The second direction D2 may thus be away from the surface being adjacent to the luminaire.

[0018] The first opening angle al is different from a2. In particular, the first opening angle (al) may be equal to or less than 170°, and the second opening angle (a2) may be equal to or greater than 190°.

[0019] After extensive testing, inventors surprisingly found that the desired light exit window opening angle (a) is dependent on the orientation of a luminaire to a surface being adjacent to the luminaire, e.g. a wall. In the indirect (projection) mode, i.e. when the luminaire light is emitted in the first direction DI towards such a surface, it is desired to have the first light exit window opening angle (al) being equal to or less than 170°, preferably in a range from 120° to 170°. On the other hand, in the direct (view) mode, i.e. when the luminaire light is emitted in the second direction D2 away from the surface being adjacent to the luminaire, it is desired to have the second light exit window opening angle (a2) being equal to or greater than 190°, preferably in a range from 190° to 240°. In the direct mode, the wall portion of the luminaire should not be visible to a viewer and should not provide any light. In the indirect mode, the light exit window opening of the luminaire should not be visible to a viewer and the wall portion, which is then directed towards the viewer should not provide any light.

[0020] Put differently, the light exit window opening can be enlarged when the luminaire is rotated to the direct mode and reduced when the luminaire is rotated to the indirect mode. Such an adjustment of the light exit window opening may be done automatically, e.g. mechanically or electrically.

[0021] According to the present invention, the luminaire light may have a first beam angle (P 1) when the tubular housing is in the first mutual rotation position (Ml), i.e. when the luminaire light is emitted in a first direction DI, and a second beam angle (P2) when the tubular housing is in the second mutual rotation position (M2), i.e. when the luminaire light is emitted in a second direction D2. The first beam angle pi may be different from the second beam angle P2. The control unit may be arranged to control the beam angle. The tubular housing may be (approximately) 180 degrees rotated in the second mutual rotation position (M2) with respect the first mutual rotation position (Ml).

[0022] The tubular housing may comprise at least one rotatable light shielding element rotatable around the rotation axis (RA) and configured to vary the opening angle (a) of the light exit window. The at least one rotatable light shielding element may comprise a reflective inner surface. The shielding element may be configured to vary the light exit window opening angle (a). In particular, the tubular housing may comprise two light shielding elements. The at least one light shielding element may be a diaphragm.

[0023] The beam angle may be optically increased by a stationary optical element being arranged stationary with respect to the stand at the outer surface of the tubular housing. In such an embodiment, the size of the optical element is greater than the size of the light exit window opening in a tangential direction. The optical element may be a diffuser, preferably a conformal diffuser and / or a light guide. In such an embodiment, the size of the optical element in a tangential direction is greater than the size of the light exit window in the second mutual rotation position (M2). The optical element may be a diffuser and / or a light guide.

[0024] The luminaire according to the present invention may further comprise at least a first and a second transverse element arranged in the compartment. In such an embodiment, the first transverse element and a first portion of the light exit window may delimit a first optical compartment, while the second transverse element and a second portion of the light exit window may delimit a second optical compartment. The first optical compartment may be arranged adjacent to the second optical compartment.

[0025] Further, the LED light source may comprise a first and a second LED light source. The first optical compartment may comprise the first LED light source being arranged on the first transverse element for emitting first LED light, and the second optical compartment may comprise the second LED light source being arranged on the second transverse element for emitting second LED light.

[0026] According to the present invention, in the first mutual rotation position (Ml) the luminaire light may comprise only the first LED light emitted by the first LED light source. Further, in the second mutual rotation position (M2) the luminaire light may comprise both the first LED light emitted by the first LED light source and the second LED light emitted by the second LED light source.

[0027] The first LED light and the second LED light may be different. Preferably, the first LED light and the second LED light have the same correlated colour temperature (CCT). In the first mutual rotation position (Ml), a central area of the first portion of the light exit window may be arranged at 0 degrees with respect to the stand. In the second mutual rotation position (M2), a central area of the combined first and second portion of the light exit window is arranged at X degrees with respect to the stand, wherein X may be in a range from 120 to 240 degrees or 170 to 190 degrees such as for example (approximately) 180 degrees. The first portion of the light exit window may be equal to the second portion of the light exit window.

[0028] In the direct mode, i.e. when the luminaire light is emitted in the second direction D2, both the first and the second LED light sources may be operating. In the indirect mode, i.e. when the luminaire light is emitted in the first direction DI, only the first LED light source may be operating. In order to keep symmetry, the rotation angle 9 from a first position wherein the first beam of light is emitted in the first direction DI to a second position wherein the first beam of light is emitted in the second direction D2 is equal to 180- 0.5 y, wherein y is the light exit window opening angle of the first optical compartment.

[0029] The present invention relates to a method for operating a luminaire as described above, the method comprising the steps of a) operating the luminaire such that the luminaire light is emitted in a first direction DI and has a first beam angle (P 1), b) rotating the luminaire over the rotation angle (9) such that the luminaire light is emitted in a second direction D2 and a second beam angle (P2) different from the first beam angle (pi).

[0030] The method of the present invention may further comprise the step of c) adjusting the intensity of the luminaire light at the light exit window such that the intensity is kept constant, wherein step c) occurs simultaneously with or after step b).

[0031] According to such an embodiment, the light intensity of the luminaire light emitted through the light exit window may be kept constant during the increase of the light exit window opening angle. In yet another example, the luminous flux can be kept constant during the increase of the light exit window opening angle. To this end, the control unit may be arranged to control the power supplied to the LED light sources.

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, of which: Fig. la is a cross-section of the luminaire in a plane perpendicular to the rotation axis in the first mutual rotation mode (Ml);

[0034] Fig. lb is a side view of the luminaire depicted in Fig. la;

[0035] Fig. 1c is a back view of the luminaire depicted in Fig. la;

[0036] Fig. Id is a front view of the luminaire depicted in Fig. la;

[0037] Fig. le is a perspective view of the luminaire depicted in Fig. la;

[0038] Fig. 2a is a cross-section of the luminaire in a plane perpendicular to the rotation axis in the first mutual rotation mode (M2);

[0039] Fig. 2b is a side view of the luminaire depicted in Fig. 2a;

[0040] Fig. 2c is a back view of the luminaire depicted in Fig. 2a;

[0041] Fig. 2d is a front view of the luminaire depicted in Fig. 2a;

[0042] Fig. 2e is a perspective view of the luminaire depicted in Fig. 2a;

[0043] Fig. 3 is a perspective view of the luminaire depicted in Figs, la-le and 2a-2e;

[0044] Fig. 4 is a transversal cross-section of the luminaire according to another embodiment of the present invention;

[0045] Fig. 5 is a transversal cross-section of the luminaire according to yet another embodiment of the present invention;

[0046] Fig. 6 is a transversal cross-section of the luminaire according to yet another embodiment of the present invention.

[0047] All the figures are schematic, not necessarily to scale, and generally only show parts which are necessary in order to elucidate embodiments of the present invention, wherein other parts may be omitted or merely suggested.

[0048] DETAILED DESCRIPTION OF THE INVENTION

[0049] The present invention will now be described hereinafter with reference to the accompanying drawings, in which exemplifying embodiments of the present invention are shown. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments of the present invention set forth herein; rather, these embodiments of the present invention are provided by way of example so that this disclosure will convey the scope of the invention to those skilled in the art. In the drawings, identical reference numerals denote the same or similar components having a same or similar function, unless specifically stated otherwise. Figs, la-le depict a luminaire 1 for providing luminaire light. The luminaire has a rotation axis (RA). The rotation axis RA coincides with a longitudinal axis of the luminaire 1.

[0050] The luminaire 1 depicted in Figs, la-le further comprises a tubular housing 2 extending along the rotation axis RA and comprising a compartment 3 enclosed by a wall portion 4 and a light-transmissive light exit window 5. The tubular housing 2 may be arranged such that it delimits an inner compartment 3 and has an inner surface 2' facing the inner compartment and an outer surface 2" facing away from the inner compartment 3. The wall portion 4 and the light exit window 5 form a closed tubular structure.

[0051] The luminaire 1 further comprises a LED light source 7 configured to emit LED light and being accommodated in the compartment 3. The light exit window 5 is configured to transmit the LED light as the luminaire light. The LED light source 7 is arranged on the inner surface 2' of the wall portion 4.

[0052] The luminaire 1 further comprises a stand 8 which carries the tubular housing 2. The tubular housing 2 and the stand 8 are rotatable with respect to each other over a rotation angle (9) around the rotation axis (RA). The term “rotatable” in the context of the present invention implies to move in such a way that all particles follow circles with a common angular velocity about a common axis.

[0053] According to the present invention, the light exit window 5 has an opening angle (a) in a cross-section perpendicular to the rotation axis, which opening angle (a) varies in dependency on the rotation angle (9).

[0054] As shown in Fig. la, the light exit window 5 has a first opening angle (al) when the tubular housing 2 and the stand 8 are in a first mutual rotation position (Ml). In such a configuration, the luminaire light is emitted in a first direction (DI). The first direction DI is the direction towards a surface 9 being adjacent to the luminaire 1. The surface 9 being adjacent to a luminaire 1 may be a surface to which the luminaire is attached, or a surface in proximity of the luminaire, e.g. a wall.

[0055] Further, the light exit window 5 has a second opening angle (a2) when the tubular housing 2 and the stand 8 are in a second mutual rotation position (M2) different from the first mutual rotation position (Ml). In such a configuration, the luminaire light is emitted in a second direction (D2) opposite to the first direction. The second direction D2 may thus be away from the surface 9 being adjacent to the luminaire 1.

[0056] The first opening angle al is different from a2. In particular, the first opening angle (al) is less than 179°, and the second opening angle (a2) is greater than 199°. Put differently, the light exit window opening can be enlarged when the luminaire is rotated to the direct mode and reduced when the luminaire is rotated to the indirect mode. Such an adjustment of the light exit window opening may be done automatically, e.g. mechanically or electrically.

[0057] The luminaire light 6 has a first beam angle (P 1) when the tubular housing 2 is in the first mutual rotation position (Ml), i.e. when the luminaire light 6 is emitted in a first direction DI, and a second beam angle (P2) when the tubular housing 2 is in the second mutual rotation position (M2), i.e. when the luminaire light is emitted in a second direction D2. The first beam angle pi is different from the second beam angle P2. The control unit may be arranged to control the beam angle.

[0058] The tubular housing 2 is 180 degrees rotated in the second mutual rotation position (M2) with respect the first mutual rotation position (Ml), as may be seen in Figs, la- le and Figs. 2a-2e, respectively. This is also illustrated in Fig. 3.

[0059] The tubular housing 301 shown in Fig. 4 comprises two rotatable light shielding elements 304 rotatable around the rotation axis (RA) and configured to vary the opening angle (a) of the light exit window 305. The rotatable light shielding elements 304 comprise a reflective inner surface 302'. The light shielding elements 304 may be diaphragms.

[0060] As shown in Fig. 5, the luminaire 101 comprise an optical element 108 being stationary arranged with respect to the stand 8 and being arranged at an outer surface 102' of the tubular housing 102. In such an embodiment, the size of the optical element 108 in a tangential direction is greater than the size of the light exit window 105 in the second mutual rotation position (M2). The optical element 108 may be a diffuser and / or a light guide.

[0061] In the embodiment shown in Fig. 6, the luminaire 201 comprises a first and a second transverse element 211, 212 arranged in the compartment- 203. In such an embodiment, the first transverse element 211 and a first portion 205' of the light exit window 205 delimit a first optical compartment 213, while the second transverse element 212 and a second portion 205" of the light exit window 205 delimit a second optical compartment 214. The first optical compartment 213 is arranged adjacent to the second optical compartment 214.

[0062] Further, the LED light source 207 comprises a first and a second LED light source 207', 207". The first optical compartment 213 comprise the first LED light source 207' being arranged on the first transverse element 211 for emitting first LED light, and the second optical compartment 214 comprises the second LED light source 207" being arranged on the second transverse element 212 for emitting second LED light.

[0063] According to the present invention, in the first mutual rotation position (Ml) the luminaire light may comprise only the first LED light emitted by the first LED light source 207'. Further, in the second mutual rotation position (M2) the luminaire light may comprise both the first LED light emitted by the first LED light source 207' and the second LED light emitted by the second LED light source 207".

[0064] The first LED light and the second LED light may be different. Preferably, the first LED light and the second LED light have the same correlated colour temperature (CCT).

[0065] In the direct mode, i.e. when the luminaire light 206 is emitted in the second direction D2, both the first and the second LED light sources 207', 207" may be operating. In the indirect mode, i.e. when the luminaire light 206 is emitted in the first direction DI, only the first LED light source 207' may be operating. In order to keep symmetry, the rotation angle 0 from a first position wherein the first beam of light is emitted in the first direction DI to a second position wherein the first beam of light is emitted in the second direction D2 is equal to 180-0.5 y, wherein y is the light exit window opening angle of the first optical compartment.

[0066] Although the present invention has been described with reference to various embodiments, those skilled in the art will recognize that changes may be made without departing from the scope of the invention. It is intended that the detailed description be regarded as illustrative and that the appended claims including all the equivalents are intended to define the scope of the invention. While the present invention has been illustrated in the appended drawings and the foregoing description, such illustration is to be considered illustrative or exemplifying and not restrictive; the present invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the appended 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

CLAIMS:

1. A luminaire (1) for providing luminaire light (6), said luminaire having a rotation axis (RA) and comprising: a tubular housing (2) extending along the rotation axis and comprising a compartment (3) enclosed by a wall portion (4) and a light-transmissive light exit window (5); a LED light source (7) configured to emit LED light and being accommodated in said compartment (3); a stand (8) which carries the tubular housing (2), wherein said tubular housing (2) and said stand (8) are rotatable with respect to each other over a rotation angle (9) around said rotation axis; and wherein the light exit window (5) is configured to transmit said LED light as said luminaire light (6), and wherein the light exit window (5) has an opening angle (a) in a cross-section perpendicular to the rotation axis, which opening angle (a) varies in dependency on the rotation angle (9), wherein said light exit window (5) has a first opening angle (al) when the tubular housing and the stand are in a first mutual rotation position (Ml), and wherein said light exit window (5) has a second opening angle (a2) when the tubular housing and the stand are in a second mutual rotation position (M2) different from said first mutual rotation position (Ml), and wherein al is different from a2, wherein said luminaire (291) further comprises at least a first and a second transverse element (211, 212) arranged in said compartment (293), wherein said LED light source comprises a first and a second LED light source (297’, 297”), wherein said first transverse element (211) and a first portion (295') of said light exit window (295) delimits a first optical compartment (213), said first optical compartment (213) comprising said first LED light source (297') being arranged on said first transverse element (211) for emitting first LED light, and wherein said second transverse element (212) and a second portion (295'') of said light exit window (295) delimits a second optical compartment (214), said second optical compartment (214) comprising said second LED light source (297”) being arranged on said second transverse element (212) for emitting second LED light; andwherein (i) in said first mutual rotation position (Ml) said luminaire light (206) comprises only the first LED light emitted by said first LED light source (207') and (ii) in said second mutual rotation position (M2) said luminaire light (206) comprises both the first LED light emitted by said first LED light source (207') and the second LED light emitted by said second LED light source (207").

2. The luminaire (1) according to claim 1, wherein said first opening angle (al) is equal to or less than 170°.

3. The luminaire (1) according to claim 1 or 2, wherein said second opening angle (a2) is equal to or greater than 190°.

4. The luminaire (1) according to any one of the preceding claims 1 to 3, wherein said tubular housing (2) is X degrees rotated in the second mutual rotation position (M2) with respect the first mutual rotation position (Ml), wherein X is in a range from 120 to 240 degrees.

5. The luminaire (1) according to any one of claims 1 to 4, wherein said luminaire light (6) has a first beam angle (pi) when said tubular housing (2) is in the first rotational position (Ml), and wherein said luminaire light (6) has a second beam angle (P2) when said tubular housing is in the second rotational position (M2), wherein pi is different from P2.

6. The luminaire (301) according to any one of the preceding claims, wherein said tubular housing (302) comprises at least one rotatable light shielding element (304) rotatable around said rotation axis (RA) and configured to vary said opening angle (a) of said light exit window (5).

7. The luminaire (301) according to claim 6, wherein said at least one rotatable light shielding element (304) comprises a reflective inner surface (302').

8. The luminaire (101) according to any one of claims 1 to 5, wherein the luminaire (101) comprises an optical element (108), wherein the optical element (108) is stationary arranged with respect to said stand (8) and being arranged at an outer surface(102") of said tubular housing (102), and wherein in a tangential direction the size of said optical element (108) is greater than the size of said light exit window (105) in the second mutual rotation position (M2).

9. The luminaire (101) according to claim 8, wherein said optical element (108) is a diffuser and / or a light guide.

10. The luminaire (201) according to any one of the preceding claims, wherein said first optical compartment (213) is arranged adjacent to said second optical compartment (214).

11. The luminaire (201) according to any one of the preceding claims, wherein in the first mutual rotation position (Ml) a central area of the first portion (205') of said light exit window is arranged at 0 degrees with respect to the stand (8), and wherein in the second mutual rotation position (M2) a combined central area of the combined first and second portion (205', 205") of the light exit window (205) is arranged at 180 degrees with respect to the stand (8).

12. The luminaire (1) according to any one of the preceding claims, wherein said LED light source (7) comprises a plurality of red LEDs configured to emit in operation red LED light, a plurality of green LEDs configured to emit in operation green LED light, a plurality of blue LEDs configured to emit in operation blue LED light, and a plurality of white LEDs configured to emit in operation white LED light having a correlated color temperature in a range from 2000K to 6500K and a CRI of at least 80; said plurality of red, green, blue and white LEDs are arranged in an array extending along the rotation axis; said luminaire (1) further comprises a control unit configured to individually control the red light emitted by said plurality of red LEDs, the green light emitted by said plurality of green LEDs, the blue light emitted by said plurality of blue LEDs, and the white light emitted by said plurality of white LEDs.

13. A method for operating a luminaire (1) according to any one of claims 1-12, said method comprising the steps of: a) operating said luminaire (1) such that said luminaire light (6) is emitted in a first direction (DI) and has a first beam angle (P 1),b) rotating said luminaire (1) over the rotation angle (9) such that said luminaire light (6) is emitted in a second direction D2 and a second beam angle (P2) different from said first beam angle (pi).

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