Lighting device

Abstract

A lighting device includes a baffle extending about an optical axis to surround a light source, and a reflector module connected to the baffle. The reflector module includes a main reflector having a light exit opening from which a light output of the lighting device is projected towards a target area, the optical axis passing through the opening, and reflective surfaces adjacent to the opening for reflecting light incident thereon away from the opening. The reflector module further includes auxiliary reflectors for adjusting the shape of the light output of the lighting device. Each auxiliary reflector has a reflective surface, and is moveable relative to the main reflector between a stowed position and a deployed position in which at least part of the reflective surface of the auxiliary reflector is exposed, by the opening of the main reflector, to reflect light incident thereon away from the target area.

Claims

1. A lighting device comprising: a light source disposed on an optical axis; a baffle extending about the optical axis and surrounding the light source; and a reflector module connected to the baffle, the reflector module comprising: a main reflector having a light exit opening from which a light output of the lighting device is projected towards a target area, the optical axis passing through the opening, and a plurality of reflective surfaces adjacent to the opening for reflecting light incident thereon away from the opening and at an angle to the optical axis; and a plurality of auxiliary reflectors for adjusting the shape of the light output of the lighting device, each auxiliary reflector comprising a reflective surface, each auxiliary reflector being moveable relative to the main reflector between a stowed position and a deployed position in which at least part of the reflective surface of the auxiliary reflector is exposed, by the opening of the main reflector, to reflect light incident thereon away from the target area.

2. The lighting device of claim 1, wherein each auxiliary reflector is slidable relative to the main reflector.

3. The lighting device of claim 1, wherein each auxiliary reflector is moveable relative to the main reflector along a linear path.

4. The lighting device of claim 3, wherein each linear path is angled to the optical axis.

5. The lighting device of claim 1, wherein each auxiliary reflector is, when in its stowed position, shielded by the main reflector from the light generated by the light source.

6. The lighting device of claim 1, wherein each of the auxiliary reflectors is moveable independently relative to the main reflector.

7. The lighting device of claim 1, wherein said at least part of the reflective surface of the auxiliary reflector is, when in the deployed position, parallel to an adjoining reflective surface of the main reflector.

8. The lighting device of claim 1, wherein the plurality of auxiliary reflectors comprises a pair of first auxiliary reflectors which approach one another with movement thereof towards their deployed positions, and a pair of second auxiliary reflectors which approach one another with movement thereof towards their deployed positions, the first auxiliary reflectors and the second auxiliary reflectors being disposed alternately about the optical axis.

9. The lighting device of claim 8, wherein the first auxiliary reflectors have a shape which is different from that of the second auxiliary reflectors.

10. The lighting device of claim 8, wherein each of the first auxiliary reflectors comprises a planar reflective surface.

11. The lighting device of claim 10, wherein the reflective surfaces of the first auxiliary reflectors are non-coplanar.

12. The lighting device of claim 8, wherein the reflective surface of each of the first auxiliary reflectors is inclined relative to a plane which is normal to the optical axis of the opening.

13. The lighting device of claim 12, wherein the reflective surface of each of the first auxiliary reflectors is inclined relative to said plane at an angle in the range from 5 to 30.

14. The lighting device of claim 8, wherein each of the second auxiliary reflectors comprises a plurality of non-coplanar reflective surfaces.

15. The lighting device of claim 14, wherein the reflective surfaces of each of the second auxiliary reflectors are inclined relative to a plane which is normal to the optical axis of the opening.

16. The lighting device of claim 14, wherein each reflective surface of the second auxiliary reflectors is parallel to a reflective surface of an adjacent first auxiliary reflector.

17. The lighting device of claim 8, wherein, when the auxiliary reflectors are in their deployed positions, at least a portion of each of the second auxiliary reflectors is disposed between the main reflector and one of the first auxiliary reflectors.

18. The lighting device of claim 17, wherein a first portion of each of the second auxiliary reflectors is disposed between the main reflector and a first one of the first auxiliary reflectors, and a second portion of each of the second auxiliary reflectors is disposed between the main reflector and a second one of the first auxiliary reflectors.

19. The lighting device of claim 8, wherein each of the first auxiliary reflectors is moveable relative to the main reflector in a direction which intersects the optical axis at a first angle, and each of the second auxiliary reflectors is moveable relative to the main reflector in a direction which intersects the optical axis at a second angle, and wherein the first angle is different from the second angle.

20. The lighting device of claim 19, wherein the second angle is 90.

21. The lighting device of claim 1, wherein the baffle comprises a first end proximate to the light source, and a second end remote from the light source, and wherein the main reflector is connected to the second end of the baffle.

22. The lighting device of claim 1, wherein each of the reflective surfaces of the main reflector which are adjacent to the opening is a planar reflector which faces away from the optical axis.

23. The lighting device of claim 1, wherein the main reflector comprises a plurality of peripheral surfaces arranged about, and angled relative to, the reflective surfaces adjacent to the opening.

24. The lighting device of claim 23, wherein each of the peripheral surfaces faces towards the optical axis.

25. The lighting device of claim 23, wherein each of the peripheral surfaces comprises a reflective surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred features of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:

(2) FIG. 1 is a perspective view, from above, of a lighting device;

(3) FIG. 2 is a side view of the lighting device;

(4) FIG. 3 is a bottom view of the lighting device;

(5) FIG. 4(a) is a front sectional view taken along line A-A in FIG. 3, FIG. 4(b) is a close-up of region B in FIG. 4(a), and FIG. 4(c) is a side sectional view taken along line C-C in FIG. 3;

(6) FIG. 5(a) is a perspective view, from above, of a baffle and a reflector module of the lighting device, with auxiliary reflectors of the reflector module in a stowed position, FIG. 5(b) is a top view of the baffle and the reflector module as shown in FIG. 5(a), FIG. 5(c) is a side sectional view taken along line A-A in FIG. 5(b), and FIG. 5(d) is a front sectional view taken along line B-B in FIG. 5(b);

(7) FIG. 6(a) is a perspective view, from above, of the baffle and the reflector module, but with the auxiliary reflectors in a first deployed position, FIG. 6(b) is a top view of the baffle and the reflector module as shown in FIG. 6(a), FIG. 6(c) is a side sectional view taken along line A-A in FIG. 6(b), and FIG. 6(d) is a front sectional view taken along line B-B in FIG. 6(b);

(8) FIG. 7(a) is a perspective view, from above, of the baffle and the reflector module, but with the auxiliary reflectors in a second deployed position, FIG. 7(b) is a top view of the baffle and the reflector module as shown in FIG. 7(a), FIG. 7(c) is a side sectional view taken along line A-A in FIG. 7(b), and FIG. 7(d) is a front sectional view taken along line B-B in FIG. 7(b); and

(9) FIG. 8(a) is a perspective view, from above, of part of the reflector module, and FIG. 8(b) is a similar view to FIG. 8(a) but with a pair of second auxiliary reflectors removed.

DETAILED DESCRIPTION OF THE INVENTION

(10) FIGS. 1 to 3 are external views of a lighting device. In this embodiment, the lighting device is in the form of a suspended lighting device 10 which is suspended from the ceiling of a room, office, hall or other domestic or commercial environment to illuminate a target area, such as a desk, a bench or a meeting table. However, the lighting device may take other forms, such as floor- or desk-standing lamp, or a wall-mounted lighting device.

(11) With reference also to FIGS. 4(a) to 4(c), the lighting device 10 comprises a light source 12 for generating visible light. In this embodiment, the light source 12 is a chip-on-board (COB) LED module which is mounted on a thermally conductive mounting plate 14. The mounting plate 14 is in thermal communication with a cooling circuit, which comprises a plurality of heat pipes 16 which engage the mounting plate 14, and a plurality of fins 18 which are connected to the heat pipes 16. Details of the cooling circuit are described in WO 2015/136241, the contents of which are incorporated herein by reference, and so will not be repeated here.

(12) The lighting device 10 is suspended from the ceiling by suspension cables (not shown) which are physically connected to the heat pipes 16. Driving electronics for the lighting device 10 are located within a separate module (not shown) which may be mounted on, or recessed into, the ceiling, or housed within the ceiling void. These electronics are connected to the light source 12 by wires which are attached to, or form part of, the suspension cables.

(13) The lighting device 10 comprises a lens 20 for creating a desired light distribution pattern from the light generated by the light source 12. In this embodiment, the lens 20 is shaped to create a light distribution pattern for illuminating a rectangular target area located beneath the lighting device 10. The lens 20 is mounted on a supporting plate 22 which extends about the mounting plate 14 for the light source 12, and which forms part of a support frame for supporting the cooling circuit. A baffle 24 surrounds both the light source 12 and the lens 20. With reference also to FIGS. 5(a) to 5(d), the baffle 24 is generally in the form of a truncated rectangular pyramid, which comprises a series of annular ridges located between a first, relatively small, open end 26 and a second, relatively large, open end 28. The first open end 26 is connected to the supporting plate 22 so that the baffle 24 is axially aligned with the optical axis X of the light source 12, as shown in FIGS. 4(b) and 4(c), with the open ends of the baffle 24 concentrically arranged on the optical axis X. The internal surface of the baffle 24 may be lined with, or formed from, reflective material so that any light emitted from the lens 20 which is incident thereon is reflected towards the second open end 28. Alternatively, or additionally, a curved or conical reflector 32 may be connected to the internal surface of the baffle 24, and disposed about the lens 20, for guiding light incident thereon towards the second open end 28 of the baffle 24.

(14) The lighting device 10 further comprises a reflector module 40. The reflector module 40 is disposed relative to the baffle 24 so that reflective surfaces of the reflector module 40 are spaced from, and located optically downstream of, the baffle 24, and so in this embodiment the reflector module 40 is located beneath the baffle 24. The reflector module 40 is connected directly to the baffle 24 via struts 42 which extends between the second open end 28 of the baffle 24 and the reflector module 40. The reflector module 40 is preferably detachably connected to the struts 42 to allow the reflector module 40 to be removed from the lighting device 10, for example for cleaning or adjustment, as discussed in more detail below.

(15) The reflector module 40 defines an aperture of variable size through which the light generated by the light source 12 is projected towards the target area. The reflector module 40 comprises a main reflector 44 and a plurality of auxiliary reflectors which are moveable relative to the main reflector 44 to adjust the size of the aperture of the reflector module 40. The main reflector 44 is connected to the baffle 24, and the auxiliary reflectors are connected to the main reflector 44. The auxiliary reflectors are moveable relative to the main reflector 44 between a stowed position and one of a number of deployed positions. When each of the auxiliary reflectors is in its stowed position, the aperture size of the reflector module 40 is at a maximum value, whereas when each of the auxiliary reflectors is in a fully deployed position, the aperture size of the reflector module 40 is at a minimum value.

(16) The main reflector 44 comprises a light exit opening 46 from which the light output of the lighting device 10 is projected towards the target area. The main reflector 44 is shaped so that the light exit opening 46 is spaced along the optical axis X from the second open end 28 of the baffle 24, and so that the centre of the light exit opening 46 is located on the optical axis X.

(17) As discussed below, when the auxiliary reflectors are in their stowed positions they are shielded from the light incident on the reflector module 40 by the main reflector 44. In this configuration of the reflector module 40, the periphery of the light exit opening 46 defines the maximum size of the aperture of the reflector module 40. The light which is incident on the reflector module 40 from the light source 12 is cropped by the main reflector 44 to generate the desired illumination pattern on the target area. In this embodiment, the illumination pattern is substantially rectangular, and so the edges of the light exit opening 46 are shaped to define the shape of the overall light beam which passes through the reflector module 40 to generate such an illumination pattern. The light exit opening 46 comprises a pair of relatively long edges 48 and a pair of relatively short edges 50. The long edges 48 are substantially parallel to one another, whereas the short edges 50 are non-parallel, having mutually inclined sections.

(18) The upper surfaces of the main reflector 44 comprise reflective surfaces 52 located adjacent to the light exit opening 46. These reflective surfaces 52 define the edges of the light exit opening 46, and are arranged to reflect light incident thereon away from the target area located beneath the lighting device 10 and towards a secondary target area, such as a ceiling upon which the lighting device 10 is mounted, for indirect, or secondary, illumination of the local environment of the lighting device 10. These reflective surfaces 52 are arranged in a non-coplanar, non-parallel arrangement, in this embodiment such that each reflective surface 52 faces away from the optical axis X to ensure that any reflected light is not incident upon, and so is not absorbed by, other components of the lighting device 10, but is instead reflected away from the optical axis and towards the secondary target area.

(19) Each reflective surface 52 of the main reflector 44 may take any shape for creating a desired illumination pattern on the secondary target area, and so may be a curved, a faceted or a planar reflector, or may comprise a combination of different shapes. In the preferred embodiment, each reflective surface 52 of the main reflector 44 is a planar reflective surface, which is inclined at an angle in the range from 5 to 30 relative to a plane which is normal to the optical axis X of the light exit opening 46. In this example, each reflective surface 52 of the main reflector 44 is inclined at an angle of approximately 15 to that plane.

(20) The main reflector 44 also comprises a plurality of peripheral walls 54 which are arranged about, and angled relative to, the reflective surfaces 52. The peripheral walls 54 serve to shield the reflective surfaces 52 of the main reflector 44 from a normal field of view of the lighting device 10. Each of the peripheral walls 54 preferably comprises reflective surfaces which face towards the optical axis to direct light, which is reflected thereon by one of the other reflective surfaces of the reflector module 40, towards the secondary target area.

(21) As mentioned above, the reflector module 40 comprises a plurality of auxiliary reflectors which are connected to, and moveable relative to, the main reflector 44 to adjust the size of the aperture of the reflector module 40, and so adjust the size of the light output of the lighting device 10. The upper surfaces of the auxiliary reflectors also comprise reflective surfaces. Each reflective surface of the auxiliary reflectors may take any shape for creating a desired illumination pattern on the secondary target area, and so may be a curved, a faceted or a planar reflector, or may comprise a combination of different shapes.

(22) In the preferred embodiment, each reflective surface of the auxiliary reflectors is a planar reflective surface.

(23) In this embodiment, each auxiliary reflector is slidable manually relative to the main reflector 44 along slots or grooves of the main reflector 44, which slots or grooves also serve to retain the auxiliary reflectors on the main reflector 44. The main reflector 44 comprises upper and lower body sections which are connected together during assembly of the reflector module 40, and between which one or more portions of each auxiliary reflector are retained.

(24) Each of the auxiliary reflectors is moveable relative to the main reflector 44 between a stowed position and one of a number of deployed positions. FIGS. 5(a) to 5(d) illustrate the configuration of the reflector module 40 when each of the auxiliary reflectors is in its stowed position. In this position, each of the auxiliary reflectors is located directly beneath the main reflector 44 so that it is shielded by the main reflector 44 from the light generated by the light source 12. In this embodiment, the reflector module 40 comprises a pair of first auxiliary reflectors 60 and a pair of second auxiliary reflectors 62. The first auxiliary reflectors 60 are disposed on first opposite sides of the light exit opening 46, and the second auxiliary reflectors 62 are disposed on second opposite sides of the light exit opening 46, and so the first auxiliary reflectors 60 and the second auxiliary reflectors 62 are disposed alternately about the optical axis X.

(25) In its stowed position, each of the first auxiliary reflectors 60 lies directly beneath, and parallel to, a respective one of the reflective surfaces 52 of the main reflector 44. Each of the first auxiliary reflectors 60 comprises a single planar reflective surface, which extends along the length of one of the relatively long edges 48 of the light exit opening 46, and has a leading edge 64 which is substantially parallel with that long edge 48 of the light exit opening 46. Similar to the reflective surfaces 52 of the main reflector 44, the reflective surface of each of the first auxiliary reflectors 60 is thus inclined at an angle of 15 relative to a plane which is normal to the optical axis X of the light exit opening 46.

(26) In contrast, in its stowed position each of the second auxiliary reflectors 62 lies directly beneath respective portions of both reflective surfaces 52 of the main reflector 44. Thus, each second auxiliary reflector 62 comprises (i) a first portion which, in the stowed position, lies directly beneath one of the reflective surfaces 52, and preferably between that reflective surface 52 and one of the first auxiliary reflectors 60, and (ii) a second portion which, in the stowed position, lies directly beneath the other reflective surface 52, and preferably between that reflective surface 52 and the other first auxiliary reflector 60.

(27) Each portion of the second auxiliary reflector 62 comprises a respective reflective surface. Thus, the reflective surfaces of each of the second auxiliary reflectors 62 are also inclined relative to a plane which is normal to the optical axis of the light exit opening, but in this case the reflective surfaces of a second auxiliary reflectors 62 are mutually relatively inclined. Each of the second auxiliary reflectors 62 has a leading edge 66 which has the same shape as the relatively short edge 50 of the light exit opening 46.

(28) Each of the auxiliary reflectors is moveable relative to the main reflector 44 from the stowed position to one of a number of deployed positions. FIGS. 6(a) to 6(d) illustrate the configuration of the reflector module 40 when the auxiliary reflectors are in a first deployed position, which is midway between the stowed position and a second, fully deployed position, and FIGS. 7(a) to 7(d) illustrate the configuration of the reflector module 40 when the auxiliary reflectors are in the fully deployed position. The auxiliary reflectors may be moveable individually, in pairs or simultaneously relative to the main reflector 44.

(29) Each auxiliary reflector is moveable relative to the main reflector 44 along a respective path, which in this embodiment is a linear path. Each of these paths is angled relative to the optical axis X. The first auxiliary reflectors 60 are moveable along a path which extends in a direction D1indicated in FIG. 4(c)which is inclined relative to the optical axis X by an angle of 105, so that the reflective surface of each first auxiliary reflector 60 remains substantially parallel to its respective reflective surface 52 of the main reflector 44 as it moves between its stowed and fully deployed positions. The second auxiliary reflectors 62 are moveable along a path which extends in a direction D2indicated in FIG. 4(b)which is substantially orthogonal to the optical axis X so that each reflective surface of each second auxiliary reflector 62 remains substantially parallel to its respective reflective surface 52 of the main reflector 44 as it moves between its stowed and fully deployed positions.

(30) Each pair of auxiliary reflectors approach one another as those auxiliary reflectors are moved away from their stowed positions. As an auxiliary reflector moves away from its stowed position, it moves across the light exit opening 46 of the main reflector 44 to reduce the aperture area of the reflector module 40, and thereby crop the light output projected towards the target area. Simultaneously with the reduction of the aperture area of the reflector module 40, the amount of light which is reflected away from the target area increases, through the exposure of the reflective surface of the auxiliary reflector to the generated light. In other words, the cropped light is not absorbed by the lighting device 10, but is instead also reflected towards the secondary target area where it can contribute to the overall illumination of the environment in which the lighting device 10 is located. The movement of the auxiliary reflector towards its fully deployed position thus gradually increases the size and/or intensity of the illumination pattern generated on the secondary target area.

(31) Each auxiliary reflector is preferably moveable relative to the main reflector 44 from the stowed position to one of a number of deployed positions, in each of which the reflective surface of the auxiliary reflector is exposed by a respective different amount to the light generated by the light source 12. With reference to FIGS. 8(a) to 8(b), in this embodiment each of the first auxiliary reflectors 60 comprises a detent member 70 on each side thereof, and the main reflector 44 comprises two series of detent recesses 72 each for engaging with a respective detent member 70 at a respective one of the deployed positions to check the motion of the first auxiliary reflector 60 relative to the main reflector 44. Similarly, with reference to FIGS. 5(d), 6(d) and 7(d), in this embodiment each of the second auxiliary reflectors 62 comprises a centrally positioned detent member 74, and the main reflector 44 comprises a series of detent recesses 76 each for engaging with the detent member 74 at a respective one of the deployed positions to check the motion of the second auxiliary reflector 62 relative to the main reflector 44. A catch or locking mechanism may be provided for securing an auxiliary reflector in a desired position.

(32) As shown solely in FIGS. 4(a) to 4(c), an additional light source 12a may be provided for illuminating the secondary target area. This additional light source 12a may be mounted on an additional thermally conductive mounting plate 14a disposed on the opposite side of the heat pipes 16 to the mounting plate 14, which allows the cooling circuit to dissipate heat generated during use of both of the light sources.