Solid state lighting device with an adjustable reflector

Abstract

The invention provides a solid state lighting device having an adjustable light output direction. In embodiments, an adjustable reflector element is provided, which is transitionable between at least a first and second orientation status, in order thereby to alter through which one or more of the light exit surfaces of the device the generated luminous output is directed.

Claims

1. A solid state lighting device comprising: a housing having a first light exit surface and a second light exit surface; at least one solid state lighting element contained in said housing for generating a luminous output; an adjustable reflector contained in said housing having an adjustable orientation status for redirecting said luminous output to one of said first light exit surface and second light exit surface dependent on said orientation status; and a control member for adjusting the orientation status of the adjustable reflector; wherein the adjustable reflector comprises a flexible planar element, wherein the adjustable reflector having the adjustable orientation status has an adjustable shape; wherein the at least one solid state lighting element comprises a plurality of solid state lighting elements which are arranged in respective first and second rows on opposing surfaces of the housing, and wherein the adjustable reflector having the adjustable shape is adjustable between: a first shape in which the luminous output of the first row of solid state lighting elements is reflected towards the first light exit surface and the luminous output of the second row of solid state lighting elements is reflected towards the second light exit surface opposing the first light exit surface; and a second shape in which the respective luminous outputs of the first and second rows of solid state lighting elements are reflected towards the first light exit surface.

2. The solid state lighting device of claim 1, wherein the adjustable reflector is mounted on a central axle extending through said housing, said central axle comprising the control member for rotating said central axle to adjust the reflector between the first shape and the second shape.

3. The solid state lighting device of claim 2, wherein: the first shape is a planar shape in which a first surface of the adjustable reflector faces the first row of solid state lighting elements and a second surface of the adjustable reflector opposite said first surface faces the second row of solid state lighting elements; the second shape is a folded shape in which a first section of the first surface faces the first row of solid state lighting elements and a second section of the first surface faces the second row of solid state lighting elements; and wherein a portion of the adjustable reflector comprising the second section is deformable.

4. The solid state lighting device of claim 3, wherein an edge portion of the second section comprises a plurality of cut-outs for allowing the second section to pass the second row of solid state lighting elements.

5. The solid state lighting device of claim 1, wherein the adjustable reflector is a reflector film.

6. The solid state lighting device of claim 1, wherein the device is a light bulb such as a replacement for a CFL light bulb.

7. A luminaire comprising the solid state lighting device of claim 1.

8. A solid state lighting device comprising: a housing having a first light exit surface and a second light exit surface; at least one solid state lighting element contained in said housing for generating a luminous output; an adjustable reflector contained in said housing having an adjustable orientation status for redirecting said luminous output to one of said first light exit surface and second light exit surface dependent on said orientation status; and a control member for adjusting the orientation status of the adjustable reflector; wherein the adjustable reflector comprises a flexible planar element, wherein the adjustable reflector having the adjustable orientation status has an adjustable position; wherein the at least one solid state lighting element comprises a plurality of solid state lighting elements which are arranged in respective first and second rows on opposing surfaces of the housing, and wherein the adjustable reflector having the adjustable shape is adjustable between: a first shape in which the luminous output of the first row of solid state lighting elements is reflected towards the first light exit surface and the luminous output of the second row of solid state lighting elements is reflected towards the second light exit surface opposing the first light exit surface; and a second shape in which the respective luminous outputs of the first and second rows of solid state lighting elements are reflected towards the first light exit surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention are described in more detail and by way of non-limiting examples with reference to the accompanying drawings, wherein

(2) FIG. 1 depicts an example compact fluorescent lamp (CFL) as known in the art;

(3) FIG. 2 depicts an example from the prior art of a solid state replacement for a compact fluorescent lamp;

(4) FIG. 3 depicts a second example from the prior art of a solid state replacement for a compact fluorescent lamp;

(5) FIGS. 4-7 illustrate the functional deficiencies of prior art solid state replacement compact fluorescent lamps;

(6) FIG. 8 depicts in perspective view a first example solid state lighting device;

(7) FIG. 9 depicts an exploded view of the first example solid state lighting device;

(8) FIGS. 10 and 11 depict perspective views of a portion of the interior of the first example solid state lighting device;

(9) FIG. 12 depicts in perspective view a second example solid state lighting device;

(10) FIG. 13 depicts an exploded view of the second example solid state lighting device;

(11) FIGS. 14 and 15 depict a first interior view of the second example solid state lighting device, corresponding to a first mode of operation;

(12) FIGS. 16 and 17 depict a second interior view of the second example solid state lighting device, corresponding to a second mode of operation; and

(13) FIG. 18 depicts a third interior view of the second example solid state lighting device.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(14) The invention provides a solid state lighting device having an adjustable light output direction. In embodiments, an adjustable reflector element is provided, which is transitionable between at least a first and second orientation status, in order thereby to alter through which one or more of the light exit surfaces of the device the generated luminous output is directed.

(15) Embodiments allow for flexibility in the applications of the device, since the output profile of the device may be adapted to fit with the particular structural or functional arrangements of the luminaire in which it is installed, for example. In this way the total luminous output of embodiments may be fully employed to illuminate only along those directions where light is most usefully directed.

(16) It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

(17) In FIGS. 8 and 9 are depicted perspective and blow-up views respectively of a first example lighting device 32 in accordance with embodiments of the invention. The device comprises an outer housing structure, formed of two main housing portions: a light output portion 40 and a body portion 60. The housing forms an elongate cuboid structure, extending from a connection cap 62 mounted at one end. The light output portion 40 of the housing comprises first 36 and second 38 light exit surfaces, which respectively comprise a bottom or end surface and a side surface of the light exit structure. In some examples, the light exit surfaces may comprise light exit windows or areas formed in or through larger surrounding surfaces.

(18) Disposed within the housing is a plurality of LED elements 44, arranged, in the particular example of FIGS. 8 and 9, in an array formation upon a supporting PCB 46. The PCB 46 is oriented such that light exit surfaces of the LED elements are arranged facing in the direction of the first light exit surface 36 of the light exit portion 40 of the housing. The PCB carrying the array of LED elements may, for example, be mounted at or around the junction between the body portion 60 and the light exit portion 40 of the housing structure, having its major surface facing toward the first light exit surface 36.

(19) Arranged between the LED elements 44 and the connection cap 62 is a heat sink structure 58 for assisting in dissipating heat away from the LED elements. The heat sink may, for example, comprise a truncated cuboid structure, of outer dimensions narrower than those of the either the body portion 60 or the light exit portion 40 of the housing structure. The heat sink may in this case for example be arranged or mounted within the outer shell of the body portion of the housing, in thermal communication with the array of LED elements. Note that in alternative examples, the heat sink may assume any number of forms and arrangements within the device (or may be exposed from the housing to ambient air), for example comprising a different shape, a different structure or a different relative position within the overall housing structure.

(20) Running along the interior of opposing side walls of the body portion 60 of the housing structure, adjacent to the bottom surface of the body portion, are opposing guide rails 54 for supporting and guiding the movement of an adjustable reflector element 48 within the housing. The adjustable reflector comprises a major planar portion having a reflective upper surface, with a slider bar 50 mounted across one end for effecting the transport of the reflector along the guide rails. The slider bar comprises protruding handle members at either end for manipulating the slider bar from outside of the housing structure. The handle members extend through two continuous narrow openings 55 formed through the bottom-most portions of the body 60 side walls, directly adjacent and parallel with each of the guide rails.

(21) The slider bar may in some examples, for instance, be itself mounted within the guide rails, and the major planar portion of the reflector merely supported by the rails, resting either above or below them. Alternatively, the planar portion of the reflector may be mounted within the guide rails while the slider bar rests beneath or atop them.

(22) The guide rails may, according to examples, comprise guide channels, each formed by two parallel, opposing rail elements which co-operate to form a narrow conduit along which one or both parts of the reflector element (the slider bar 50 and planar portion) are arranged to slide. The height of said channels may be formed such that the channel partially grips the two side edges of the planar portion of the reflector 48. Alternatively, the height of the channels may be formed such that there is little or no resistance to the sliding of the reflector along the channels, and the channels merely acts to contain or hold the reflector at a particular vertical position within to the housing, i.e. to support the reflector vertically, and to prevent slipping or transit of the reflector into an upper portion of the housing.

(23) When the device is in its final constructed state (as illustrated by FIG. 8), the body portion 60 of the housing is connected directly to connection cap 62 (or connected via heat sink 58), and the reflector 48 is positioned within said body portion, resting upon its bottom surface, or supported parallel to the bottom surface within or on the guide rails 54. The reflector is positioned such that the end handle elements of the slider bar 50 are disposed protruding through openings 55. By sliding the slider barby means of the protruding handle elementsfrom a first position, adjacent to the connection cap 62, to a second position, adjacent to the light exit portion 40 of the housing structure, the reflector may correspondingly be slid between an initial state in which it is positioned wholly or substantially within the body portion of the housing, and a final state, in which at least a portion of the reflector is disposed within the light exit portion 40 of the housing.

(24) FIGS. 10 and 11 depict the interior of the light exit portion 40 of the housing structure, wherein the guide rails 54, continue from their path through the body portion, but curve upwards on entering the light exit portion 40, extending from the base of the housing to the top of the housing, as they span the light exit portion 10, effectively defining a curved diagonal partition across it.

(25) As the reflector 48 is slid along the guide rails, from its initial position, substantially within the body 60 of the housing, to its second position, partially within the light exit portion 40 of the housing, the curved portion of the guide rails induces the reflector to bend in congruence with the curvature of the rails. Once the reflector has been fully slid along the railssuch that one end is disposed adjacent to first light exit surface 36the portion of the reflector supported by the curved guide rails is bent so as to define a curved plane which forms a partition between the solid state lighting elements 44 and the first light exit window 36. Moreover, as illustrated in FIG. 11, the curvature defined by the curved rails 54 is such that light 70 incident upon the reflector 48, when in this curved/engaged state, is redirected by the upper (reflective) surface of the reflector in the direction of the second light exit surface 38.

(26) Hence, by sliding the slider bar 50 between its first position, adjacent to the connection cap 62, and its second position, adjacent to the light exit portion 40 of the housing, the reflector 48 is moved between an initial idle position, in which it is hidden from the light paths of the LED elements, to a second engaged position, it which it is interposed, at a curved incline, between the LED elements 44 and the first light exit window 38. When the reflector is in its first (idle) position, light is emitted from the housing predominantly or entirely through the first light exit surface 36. When the reflector is in its second (engaged) state, light is emitted from the housing predominantly or entirely through the second light exit surface.

(27) Note that according to some examples, the heat sink element 58 may comprise further guide rails 66 for guiding or supporting the transport of the reflector element 48 between the connection cap 62 and the body portion of the housing. For example, the further guide rails may have the same shape and construction as the guide rails 54 of the body portion, and be arranged or positioned along side-walls of the heat sink so as to align and co-operate with the guide rails of the body housing portion 60. In alternative examples, however, such as in cases where the heat sink is mounted or disposed within the body portion 60 of the housing itself (in thermal communication with the LED elements), the heat sink may comprise cut-outs or notches formed along either side of its bottom-most surface, shaped and aligned to co-operate with the guide rails 54 of the housing. In this way, the heat sink may fit within the outer shell of the housing, without snagging or interfering with the guide rails 54 or the sliding operation of the reflector element 48.

(28) Referring again to FIGS. 4-7, embodiments of the invention, in accordance with the examples of FIGS. 8-11, resolve the difficulty of compatibility with differently oriented or arranged luminaires, since the light output direction may be switched to match the intended application. For example, in the case that the lamp 32 is to be installed within a vertically oriented luminaire, such as those depicted in FIGS. 6 and 7, the slider may be manipulated into its first position, adjacent to the connection cap, such that the reflector is held withdrawn from the light output portion of the housing, in its idle/flat state. In this way, light from the LED elements is directed substantially through the end of the device (i.e. through the first light exit surface 36). Alternatively, in the case that the lamp 32 is to be installed within a horizontally oriented luminaire, such as those depicted in FIGS. 4 and 5, the slider may be manipulated into its second position, adjacent to the light exit portion 40, such that the reflector is slid into its curved/engaged state within the light exit portion of the housing. In this state, the reflector is arranged such that light is blocked from passing through the first light exit surface, and is redirected toward the second light surface. Hence light in this case is output through a side surface of the device, and not an end surface, rendering it suitable for use in the horizontal type luminaire of FIGS. 6 and 7.

(29) By way of non-limiting example, the planar portion of the reflector element may comprise a reflector film, for example a layer of reflector film formed over the major surface(s) of a base layer of flexible material, or simply a layer of reflector film on its own.

(30) The connector cap 62 may be a connector cap of any variety, suitable for making electrical and mechanical connection with an existing light fitting, for example, so as to render the lighting device 32 suitable for installation within an existing luminairefor example as a replacement to an existing compact fluorescent lamp. The cap may, by way of example, comprise a screw cap fitting, a bayonet fitting, a GU-type fitting or a MR-type fitting. The cap may be made out of a suitable electrically conductive material, for example.

(31) According to the above-described example, or any other examples or embodiments, the body portion 60 and/or light exit portion 40 of the housing structure may be made of plastics. In particular, it may be desirable that the light exit portion 40 of the housing comprise a diffused plastic cover, for example translucent or frosted plastic, to thereby provide output illumination of an even or homogeneous intensity. A diffused plastic cover may avoid problems of glare, or avoid the occurrence of so-called bright spots in the output distribution, wherein the luminous output comprises isolated points of high intensity surrounded by a broader area of much lower intensity. Additionally, diffused plastic may be preferred for other aesthetic reasons, for example to give to the housing of the lampwhen switched onan even, homogenous appearance.

(32) However, note that in alternative examples, the light exit portion of the housing may comprise a transparent outer material, for example a transparent plastic. This may be preferred, for example, in cases where output intensity is desired to be maximised, at the cost of homogeneity of output, or for example where the output is intended to be more narrowly focussed, for example by one or more beam shaping elements.

(33) In FIGS. 12 and 13 are depicted perspective and exploded views respectively of a second example solid state lighting device in accordance with embodiments of the invention. As with the example of FIGS. 8-11, the device comprises an elongate outer housing structure, extending from a connection cap 62. As is clear from FIG. 13, in this example the housing structure comprises only a single section (light exit portion 40), within which are housed both the LED elements 44 and the adjustable reflector 48. For brevity, the light exit portion 40 of the housing shall for the purposes of description of the present embodiment be referred to simply as the housing 40.

(34) The housing 40 comprises opposing first 36 and second 38 light exit surfaces, each forming a respective horizontal or radial surface of the housing structure. The LED elements are arranged along respective first 76 and second 78 rows, mounted on respective first 84 and second 86 PCBs, running along opposing surfaces of the housing 40. The LEDs of each row are oriented so as to emit light across the body of the housing in the direction of the opposing row. Positioned between the rows, mounted along its centre by a central axle 90, is the adjustable reflector 48, arranged in two planar sections, pivotable about the central axle in order to deform or fold the reflector into different arrangements or orientations.

(35) The structure of the reflector 48 within the housing 40 is depicted more clearly in FIGS. 14-17, which illustrate the two different orientations or shapes which the reflector may be manipulated, by means of rotation of the axle 90, to adopt. The axle divides the reflector into first and second portions (shown extending toward the left and right of the axle respectively in FIGS. 14-17), at least the second of which is rotatable or pivotable about the axle 90 between an upwards, inclined position (FIGS. 14 and 15) and a downwards, declined position (FIGS. 16 and 17). In various examples, the first (left) portion might also be pivotable in a similar manner.

(36) The reflection comprises a first (upper) reflective surface 102 and a second (lower) reflective surface 104. The upper reflective surface 102 is divided by the axle into a first section 110 and a second section 112, and likewise the lower reflective surface 104 is divided into an a first section 116 and a second section 118. The axle hence effectively divides the reflector into left-hand and right-hand portions, each comprising upper (110 and 112 respectively) and lower (116 and 118) reflective surface sections.

(37) The central axle may be twistable or rotatable within the structure by means of an external control element, said rotation acting to thereby deform or bend or pivot the second (right-hand) portion of the reflector from a flat shape (FIGS. 14 and 15), wherein it is oriented parallel with the left-hand portion, to a folded or bent shape (FIGS. 16 and 17) wherein it is disposed at an angle to the left hand portion. As shown in FIG. 13, the axle 90 furthermore comprises a rotation locking member 92 which allows the orientation/shape of the reflector 48 to be fixed (temporarily) after rotation of the axle.

(38) FIGS. 14 and 15 illustrate the first arrangement of the adjustable reflector 48, wherein the reflector is oriented at an angle between the two sides of the housing, extending form a point below the first row 76 of LEDs on the left side of the housing (as shown in FIGS. 14 and 15) to a point above the second row 78 of LEDs on the right hand side of the housing. In this arrangement, the upper surfaces 110, 112 of both the first and second portion of the housing are disposed within the light path of the first row of LED elements, and angled so as to redirect light incident from said first row in the direction of the first (upper) light exit surface 36 of the housing. At the same time within this arrangement, the lower reflective surfaces 116, 118 of both the first and second portions of the reflector are disposed within the light path of the second row 78 of LED elements, and angled such that light incident from said second row is redirected toward the second (lower) light exit surface 38 of the housing. Hence, when the reflector is oriented according to the arrangement of FIGS. 14 and 15, the total luminous output of the device is split between the first and second (upper and lower) light output surfaces. In this mode of operation, light is output though both of these horizontal surfaces, and hence the device may be used to direct light in both directions at once.

(39) FIGS. 16 and 17 illustrate the second possible arrangement of the adjustable reflector 48 according to the example device depicted in FIGS. 12 and 13. In this arrangement, the reflector is bent into a downward facing quasi V-shape, with the left-hand portion of the reflector extending from the axle 90 to a point below the first row 76 of LED elements (in common with the arrangement of FIGS. 14 and 15), and the right-hand portion extending from the axle 90 to a point below the second row 78 of LED elements. In this arrangement, the first section 110 of the upper surface 102 of the reflector 48 is disposed within the light path of the first row 76 of LEDs, and angled to redirect incident light in the direction of the first (upper) light exit window 36, and the second section 112 of the upper surface 102 of the reflector 48 is disposed within the light path of the second row 78 of LEDs, and also angled to redirect incident light in the direction of the first (upper) light exit surface 36. Hence, when the reflector is oriented according to the arrangement of FIGS. 16 and 17, the total luminous output of the device is directed toward only a single exit surfacenamely, the first exit surface 36and the device correspondingly outputs light only in this single direction.

(40) The adjustable reflector of the example device of FIGS. 12 and 13 hence allows for the device to be switched between a uni-directional modein which light is output through only a single exit surfaceand a bi-directional modein which light is output through two opposing exit surfaces. In the latter case, the device may be suitable for use in almost any luminairefor example in both the vertical 24 and horizontal 22 luminaire varieties of FIGS. 4 and 6 respectively. However, by switching to the uni-directional (horizontal output) mode of operation, the lamp is rendered specially applicable for efficient use in horizontal-type luminaires, since light is concentrated through a single horizontal window, and distributed evenly across said window.

(41) In FIG. 18 is depicted a second view of the reflector 48, from the top (or first exit window 32) side of the device. More clearly visible are a plurality of notches or cut-outs formed along the edge of the second portion of the reflector, spaced and shaped so as to allow said portion to slide between angular positions above and below the second row 78 of LED elements without snagging the LED elements themselves. In alternate examples, in which it is desirable that the first portion of the reflector also pivot in a similar way, equivalent notches may additionally be provided along the edge of the first portion of the reflector.

(42) According to this or any other embodiment of the invention, the PCB(s) carrying the plurality of solid state lighting elements 44 may be formed with use of high quality printing oil, in order to maximise the luminous output efficiency of the device.

(43) The lighting device 32 according to one or more embodiments of the present invention may be advantageously included in a luminaire such as a holder of the lighting device, e.g. a ceiling light fitting, or an apparatus into which the lighting device is integrated, e.g. a cooker hood or the like. Other suitable types of luminaires, e.g. advertising luminaire comprising an array of tubular lighting devices and so on, will be apparent to the skilled person.

(44) It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word comprising does not exclude the presence of elements or steps other than those listed in a claim. The word a or an preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several distinct elements. In the device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. 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.