LED filament arrangement

Abstract

There is provided a light emitting diode, LED, filament arrangement 100 configured to provide LED filament arrangement light 105 and comprising: a plurality of LED filaments 110 configured to emit respective LED filament light 115, an at least partially light-transmissive enclosure 120, wherein the enclosure at least partially encloses the plurality of LED filaments, a partitioner 130 arranged within the enclosure, wherein the partitioner and the enclosure define a plurality of partitions 140, wherein the partitioner comprises a plurality of diffuse reflective surfaces 135 configured to reflect light by diffuse reflection, wherein at least one reflective surface of the plurality of diffuse reflective surfaces and at least one LED filament of the plurality of LED filaments are arranged in each partition.

Description

[0001] Led filament arrangement

[0002] FIELD OF THE INVENTION

[0003] The present invention generally relates to the field of light-emitting diode, LED, filament arrangements. More specifically, the present invention relates to a LED filament comprising light converting material.

[0004] BACKGROUND OF THE INVENTION

[0005] The use of light emitting diodes (LEDs) for illumination purposes continues to attract attention. Compared to incandescent lamps, fluorescent lamps, neon tube lamps, etc., LEDs provide numerous advantages such as a longer operational life, a reduced power consumption, and an increased efficiency related to the ratio between light energy and heat energy. In particular, LED lamps are highly appreciated as they may be very decorative and versatile in appearance.

[0006] It is of interest to combine the advantageous properties of LEDs according to the above with the advantageous properties of filament lamps. Filament lamps present an aesthetic design as well as a wide light distribution angle. It will be appreciated that combining filament lamps with the properties of LEDs has become a trend due to the high efficiency of LEDs whilst achieving the resemblance to a traditional incandescent light bulb with a visible filament.

[0007] In addition to the above-mentioned combination of features of LEDs and traditional incandescent light bulbs, it will be appreciated that it may be desirable to emit light from such an arrangement in an efficient manner whilst at the same time fulfilling certain lighting requirements. For example, including different combinations of transmissive and reflective surfaces and objects together with the LED filament may accomplish these objectives. Certain configurations of LED filaments and transmissive / reflective surfaces may thus be used to create arrangements with advantageous light distribution, aesthetics and / or efficiency.

[0008] Hence, it is of interest to provide a LED filament arrangement which can provide aesthetic and efficient lighting. SUMMARY OF THE INVENTION

[0009] It is an object of the present invention to provide a LED filament arrangement which can present the traditional appearance of light bulbs combined with the efficiency of LEDs, whilst at the same time providing improved lighting in an efficient manner.

[0010] This and other objects are achieved by a LED filament arrangement having the features in the independent claim. Preferred embodiments are defined in the dependent claims.

[0011] Hence, according to the present invention, there is provided a light emitting diode, LED, filament arrangement configured to provide LED filament arrangement light. The LED filament arrangement comprises a plurality of LED filaments configured to emit respective LED filament light. The LED filament further comprises an at least partially light- transmissive enclosure, wherein the enclosure at least partially encloses the plurality of LED filaments. The LED filament further comprises a partitioner arranged within the enclosure, wherein the partitioner and the enclosure define a plurality of partitions. The partitioner comprises a plurality of diffuse reflective surfaces configured to reflect light, by diffuse reflection. At least one reflective surface of the plurality of diffuse reflective surfaces and at least one LED filament of the plurality of LED filaments are arranged in each partition (respectively). For example, at least one reflective surface of the plurality of diffuse reflective surfaces and one LED filament of the plurality of LED filaments may be arranged in each partition (respectively).

[0012] Thus, the present invention is based on the concept or idea of providing a LED filament arrangement which can provide efficient lighting whilst providing (diffuse) lighting. This is achieved by having a plurality of LED filaments arranged in separate partitions in an enclosure, wherein the partitions are defined by a partitioner that comprises a reflective surface in each partition, and wherein the diffuse reflective surfaces are configured to reflect light by diffuse reflection. Thus, the present invention provides a LED filament arrangement which may emit LED filament arrangement light in a plurality of directions, wherein the LED filament light comprises diffuse light reflected via the diffuse reflective surfaces from the LED filaments, resulting in a LED filament arrangement that may imitate a single light source in a more efficient manner.

[0013] It will be appreciated that the LED filament arrangement may provide diffused light, which may be more aesthetically pleasing, and at the same time provide an improved light distribution. It will be further appreciated that the combination a plurality of partitions with at least one respective LED filament and at least one respective reflective surface configured to reflect light, e.g. by diffuse reflection, may together provide an imitation of a single light source. For example, this may imitate post top lamps and lanterns.

[0014] The present invention is further advantageous in that the use of LED filaments in the LED filament arrangement of the present invention provides an arrangement that resembles traditional incandescent light bulb arrangements, whilst being more efficient, at least in terms of energy.

[0015] According to the present invention there is provided a plurality of LED filaments configured to emit respective LED filament light. The LED filament arrangement further comprises an at least partially light-transmissive enclosure, wherein the enclosure at least partially encloses the plurality of LED filaments. By the term “enclosure” it is here meant a cover, enclosure, element, component, part, arrangement, or the like, which is configured or arranged to at least partially cover, surround, encapsulate, and / or enclose the plurality of LED filaments. For example, the enclosure may be a lamp post cover. By the term “light-transmissive enclosure”, it is here meant an enclosure which is transparent and / or translucent. The LED filament arrangement further comprises a partitioner arranged within the enclosure, wherein the partitioner and the enclosure define a plurality of partitions. The partitioner may be substantially any element, component, part, arrangement, or the like, which is configured or arranged to separate, split, isolate and / or divide the plurality of LED filaments, such that the LEDs filaments are arranged into separate / different partitions inside the enclosure. For example, the partitioner may be internal walls to the enclosure, that protect, block, guard, and / or shield each LED filament from the light from the other LED filaments to create separate partitions. The plurality of partitions may be compartments, sections, sectors, and / or slices formed by spaces at least partially enclosed by the enclosure and the partitioner.

[0016] The partitioner comprises a plurality of diffuse reflective surfaces configured to reflect light, wherein at least one diffuse reflective surface of the plurality of diffuse reflective surfaces and at least one LED filament of the plurality of LED filaments are arranged in each partition. The plurality of diffuse reflective surfaces may be reflectors. Diffuse reflection is reflection from a surface such that a ray incident on the surface is scattered at many angles rather than just one angle, leading to the effect that diffuse reflection may provide a more dispersed / spread light distribution. In other words, the LED filament arrangement light may comprise more diffuse light due to the diffuse reflection. It is to be understood that the LED filament arrangement may comprise two or more partitions defined by the partitioner and the enclosure, and that e.g. one or more LED filaments and one or more diffuse reflective surfaces are arranged inside each partition. For example, the LED filament arrangement may comprise a partitioner that forms four distinct and separate partitions inside the enclosure, wherein the LED filament arrangement comprises one LED filament arranged inside each partition and the partitioner comprises one reflective surface in each partition. Furthermore, it is to be understood that the LED filament arrangement may comprise a plurality of LED filaments arranged inside each partition, as well as a plurality of diffuse reflective surfaces inside each partition.

[0017] According to an embodiment of the present invention, one or more or each LED filament of the plurality of LED filaments is a spiral LED filament. Other configurations of the LED filament arrangement are also possible, like for instance one or more straight filaments or a combination of straight and spiral filaments, The present embodiment is advantageous in that it may provide an even more pleasing light distribution and an even more efficient lighting for some applications, such as street lanterns.

[0018] According to an embodiment of the present invention, the LED filaments are configured in the partitioner such that at a viewing distance of less than 10 meters or less than 20 meters only 1 or 2 filaments are visible. This will strengthen the effect that the combination of a plurality of partitions with at least one respective LED filament and at least one respective reflective surface configured to diffusely reflect light, may together provide the effect of mimicking a single light source.

[0019] According to an embodiment of the present invention, the LED filament arrangement elongates along a first axis, A, and wherein the enclosure comprises a respective light exit window having a respective opening angle sector, 0n, in relation to the first axis, A, for each of the plurality of partitions, such that the LED filament light is arranged to exit the enclosure via the light exit windows. By the term “light exit window” it is here meant an opening from a partition which provides an exit or output for the respective LED filament light in each partition to exit the partition. It is to be understood that each partition may have at least one light exit window. For example, the LED filament arrangement may comprise four partitions with a respective light exit window. The present embodiment is advantageous in that the LED filament arrangement provides an even more pleasing and practical light distribution.

[0020] According to an embodiment of the present invention, each opening angle sector, 0n, is different from the other opening angle sectors, 0n. In other words, the opening angle sectors, 0n, do not overlap. The present embodiment is advantageous in that the LED filament arrangement may emit the LED filament arrangement light in a more efficient and / or uniform manner. For example, the light distribution of the LED filament light may be more uniform, since there is no overlap between the opening angle sectors, 0n, that could create local intensity peaks at the overlapping opening angles. Hence, the present embodiment is further advantageous in that the light distribution of the LED filament arrangement light is more aesthetically pleasing.

[0021] In embodiments, at least two partitions of the plurality of partitions may have a different opening angle sector, 0n. For example, the difference in opening angle sector, 0nmay be at least 10 or at least 20 degrees.

[0022] According to an embodiment of the present invention, the light exit windows are arranged to allow LED filament light to be emitted omnidirectionally with respect to the first axis A. In other words, LED filament light is emitted in all directions around the first axis, A. For example, an observer moving around the LED filament arrangement in a circle in a plane intersecting the LED filament arrangement and perpendicular to the first axis, A, may see LED filament arrangement light at all angles around the LED filament arrangement. The present embodiment is advantageous in that the LED filament arrangement provides a more pleasing and efficient light distribution. Furthermore, the present embodiment is advantageous in that there are no dark spots with no LED filament arrangement light, resulting in the effect that the present embodiment provides a more useful / practical light distribution. In addition to this, the present embodiment is advantageous in that the LED filament arrangement may better imitate a single light source and thus be more aesthetically pleasing.

[0023] According to an embodiment of the present invention, each LED filament of the plurality of LED filaments is arranged at a first distance, Di, perpendicular to the first axis, A, from the respective light exit window for the respective partition and at a second distance, D2, perpendicular to the first axis, A, from the partitioner, wherein Di and D2 fulfil DI>D2. In other words, in a partition, a distance from a LED filament to a light exit window of the partition is larger than the distance from said LED filament to a reflective surface. The present embodiment is advantageous in that the LED filament arrangement provides improved diffuse lighting and / or improved imitation of a single light source, and / or a more pleasing light distribution. According to an embodiment of the present invention, the partitioner is an at least (partly) light-transmissive partitioner. For example, the partitioner may have a transmissivity in a range from 5% to 30%.

[0024] It is to be understood that any part of the partitioner may be light-transmissive, e.g. the diffuse reflective surfaces may be light-transmissive while also being reflective. The partitioner may be light transmissive to a variety of different degrees, e.g. between 100% light transmissive and 1% light transmissive. The present embodiment is advantageous in that the LED filament arrangement may provide an improved diffuse lighting and a more pleasing light distribution. Furthermore, the present embodiment allows for a further improved imitation of a single light source and a more aesthetically pleasing light distribution.

[0025] In embodiments, the partitioner may be a transflective partitioner.

[0026] According to an embodiment of the present invention, the plurality of diffuse reflective surfaces comprises a diffuse reflective material having a reflectivity, R, of at least 70%. In an embodiment, the reflectivity, R, is preferably at least 75%, more preferably at least 80% and most preferably at least 85%. The diffuse reflective material is a material with properties that allow light that impinges on the material to be reflected in a diffuse manner. The present embodiment is advantageous in that the LED filament arrangement may provide improved diffuse lighting and / or allow the LED filament arrangement to imitate a single light source better. Hence, the present embodiment provides a more pleasing light distribution.

[0027] According to an embodiment of the present invention, the partitioner comprises a light-transmissive material having a light-transmission, T, of 5% to 30%. The present embodiment is advantageous in that the LED filament arrangement may allow the LED filament arrangement to imitate a single light source better. Further, the present embodiment provides a more pleasing light distribution.

[0028] According to an embodiment of the present invention, the partitioner has a cross-shape or asterisk-shape. By “cross-shape” it is here meant, but not limited to, a shape consisting of four different elongated parts arranged in a cross shape that form a single shape. By “asterisk-shape” it is here meant, but not limited to, a shape consisting of 5 or more different elongated parts arranged in an asterisk shape that form a single shape. In a preferable embodiment, the asterisk-shape is a 5-pointed or 6-pointed asterisk, i.e. the asterisk-shape comprises 5 or 6 elongated parts arranged in an asterisk shape. The present embodiment is advantageous in that the LED filament arrangement may provide a more pleasing light distribution. According to an embodiment of the present invention, the partitioner is in thermal contact with the plurality of LED filaments, wherein the partitioner comprises a thermally conductive material and is arranged to dissipate heat from the plurality of LED filament upon operation of the LED filament arrangement, and / or that the partitioner is in physical contact with the plurality of LED filaments. The partitioner may be in direct physical contact with the plurality of LED filaments. Hence, the present embodiment allows excessive heat from the LED filament to be dissipated via the partitioner. The present embodiment is advantageous in that the thermal management of the LED filament arrangement is improved and / or in that the structural stability is improved due to mechanical fixation.

[0029] According to an embodiment of the present invention, at least a first part of the partitioner extends from a center of the enclosure to or towards an inner surface of the enclosure. The partitioner may thus be in contact with the enclosure. The present embodiment is advantageous in that the partitions are better separated which provides improved control of the light distribution. Furthermore, the present embodiment is advantageous in that the LED filament arrangement is more structurally stable. Preferably, the first part may extend over at least 80% of the distance from the center to the enclosure.

[0030] In embodiments, the enclosure may have an inner width (W 1) (e.g. the inner diameter of the enclosure) and the partitioner may have an outer width (W2) (e.g. the outer diameter of the partitioner), wherein O.6<W2 / W1<1, preferably O.7<W2 / W1<1, more preferably O.8<W2 / W1<1, most preferably O.9<W2 / W1<1. The obtained effect is improving mimicking a single light source. The reason is at many viewing angles only a single light source is visible.

[0031] In an embodiment in which the at least a first part of the partitioner extends from a center of the enclosure to an inner surface of the enclosure and wherein the partitioner comprises a thermally conductive material and is arranged to dissipate heat from the plurality of LED filament, the present embodiment is advantageous in that it provides a safer arrangement, with an improved ability to dissipate heat from the plurality of LED filaments.

[0032] According to an embodiment of the present invention, the plurality of LED filament comprises at least n LED filaments configured to emit a respective LED filament light, wherein 6 > n > 3. The partitioner and the enclosure define n partitions, and a respective LED filament of the plurality of LED filaments is arranged in a respective partition of the partitions. In other words, the LED filament arrangement comprises four or more partitions, with a respective LED filament in each partition. The partitioner may comprise a reflective surface in each partition. The present embodiment is advantageous in that the LED filament arrangement may provide an even more pleasing light distribution.

[0033] According to an embodiment of the present invention, there is provided a LED filament lamp comprising the LED filament according to an embodiment of the present invention, wherein the enclosure is an at least partially light-transparent envelope. The LED filament lamp further comprises a base arranged to mechanically and electrically connect the LED lamp to a socket of a luminaire. In an embodiment, the base comprises a cap arranged to mechanically and electrically connect the LED lamp to a socket of a luminaire.

[0034] According to an embodiment of the present invention, there is provided a luminaire, comprising the LED filament arrangement according to an embodiment of the present invention, or the LED filament lamp according to an embodiment of the present invention. The luminaire may be part of a streetlight, meaning that a streetlight may comprise the luminaire connected to a pole.

[0035] Further objectives of, features of, and advantages with, the present invention will become apparent when studying the following detailed disclosure, the drawings, and the appended claims. Those skilled in the art will realize that different features of the present invention can be combined to create embodiments other than those described in the following.

[0036] BRIEF DESCRIPTION OF THE DRAWINGS

[0037] This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiment(s) of the invention.

[0038] Fig. l is a schematic view of a LED filament arrangement according to an exemplifying embodiment of the present invention.

[0039] Figs. 2A-2C are schematic vires of a LED filament arrangement according to exemplifying embodiments of the present invention.

[0040] Fig. 3 is a schematic view of a luminaire according to an exemplifying embodiment of the present invention.

[0041] DETAILED DESCRIPTION

[0042] Fig. 1 is a schematic view of a LED filament arrangement 100 according to an exemplifying embodiment of the present invention.

[0043] The LED filament arrangement 100 in Fig. 1 is configured to provide LED filament arrangement light 105. The LED filament arrangement 100 comprises a plurality of LED filaments 110 configured to emit respective LED filament light 115. Henceforth, the term “plurality of’ and the normal plurality inflection may be used interchangeably, such as “a plurality of LED filaments 110” and “LED filaments 110”. The LED filament arrangement light 105 comprises the LED filament light 115. The LED filament arrangement light 105 and / or the LED filament light 115 may be white light e.g. having a correlated color temperature in a range from 1700K to 6500K and / or a CRI of at least 80.

[0044] The LED filament arrangement 100 further comprises an enclosure 120, wherein the enclosure 120 at least partially encloses the plurality of LED filaments 110. The enclosure 120 is at least partially light-transmissive, i.e. the enclosure may comprise a light- transmissive material. The enclosure 120 may comprise different materials, such as metal or plastic. The enclosure 120 may have different designs and shapes, e.g. a street lantern comprising a frame and a plurality of separated windows allowing light to be emitted in different directions. The LED filament arrangement 100 further comprises a partitioner 130 arranged within the enclosure 120. The partitioner 130 is thus at least partially enclosed by the enclosure 120 and may be fully enclosed by the enclosure 120. The partitioner 130 and the enclosure 120 define a plurality of partitions 140. The partitioner 130 comprises a plurality of diffuse reflective surfaces 135. The diffuse reflective surfaces 135 are configured to reflect light, e.g. by diffuse reflection, i.e. spread / scatter light at many different angles. Each partition 140 has at least one reflective surface 135 and at least one LED filament 110 arranged in it. For example, at least 90% or the complete outer surface of the partitioner 130 may be reflective.

[0045] In Fig. 1, the LED filament arrangement 100 comprises two partitions 140 with a respective LED filament 110 and reflective surface 135. The LED filament light 105 may comprise LED filament light 115 and diffused LED filament light 115 from reflections of the diffuse reflective surfaces 135. The LED filament arrangement 100 may imitate the lighting distribution of a single light source by the plurality of LED filaments 110 and the plurality of diffuse reflective surfaces 135. The LED filament arrangement 100 elongates along a first axis, A, towards the viewer.

[0046] Figs. 2A-2C are schematic views of a LED filament arrangement 100 according to exemplifying embodiments of the present invention. It should be noted that the LED filament arrangement 100 shown in Figs. 2A-2C have several features in common with the LED filament arrangement 100 shown in Fig. 1, and it is hereby referred to Fig. 1 and the associated text for an increased understanding of some of the features and / or functions of the LED filament arrangement 100. Furthermore, the different LED filament arrangements 100 in Figs. 2A-2C have several features in common, and it is hereby referred to the other figures of Figs. 2A-2C for an increased understanding when interpreting any one of Figs. 2A-2C.

[0047] In Figs. 2A-2C the LED filament arrangement 100, elongating along a first axis, A, towards the viewer, comprises a plurality of LED filaments 110. The LED filament arrangement 100 further comprises an at least partially light-transmissive enclosure 120 and a partitioner 130, wherein the partitioner 130 and the enclosure define a plurality of partitions 140. The partitioner 130 comprises at least one reflective surface 135 in each partition 140 of the plurality of partitions 140. The LED filament arrangement 100 comprises at least one LED filament 110 in each partition 140.

[0048] The plurality of diffuse reflective surfaces 135 may comprise a diffuse reflective material having a reflectivity, R, of at least 70%. Thus, a relatively high reflection of the LED filament light is allowed, such that the LED filament arrangement light comprises diffused light originating from the LED filaments 110 and reflected by the diffuse reflective surfaces 135. In a further example, the reflectivity, R, is preferably at least 75%, more preferably at least 80% and most preferably at least 85%.

[0049] The LED filaments 110 may be spiral LED filaments. The spiral LED filaments 110 may extend in a direction parallel with the first axis, A. The LED filament arrangement 100 may extend along the first axis, A. Alternatively or additionally, the LED filaments may be straight filaments. The partitioner 130 may extend in a plurality of directions depending on the number of partitions 140 and the design of the LED filament arrangement 100, wherein the partitioner 130 extends at least in a direction parallel with the first axis, A.

[0050] In Fig. 2A, the LED filament arrangement 100 comprises four LED filaments 110 and four diffuse reflective surfaces 135. In each partition 140, there is arranged one LED filament 110 and one reflective surface 135, wherein the reflective surface 135 is part of the partitioner 130. Here, the partitioner 130 is shaped as a cross, wherein the diffuse reflective surfaces 135 are part of the partitioner 130 and face the respective LED filament 110 in their partition 140, such that they may reflect LED filament light by diffuse reflection. The diffuse reflective surfaces 135 may for example be V-shaped arranged at the inner-most part of the partitioner 130, at the center of the cross-shaped partitioner 130. It is to be understood that the partitioner 130 may comprise different parts assembled to form a single unit with the one partitioner 130. In an example, the reflective surface 135 may be a surface attached / mounted on the partitioner 130. In Fig. 2a, a first part 132 of the partitioner 130 extends from a center 122 of the enclosure 120 to an inner surface 127 of the enclosure 120. The first part 132 and the inner surface 127 may be attached / mounted together to form a joint part of the LED filament arrangement 100. Preferably, the first part extends over at least 80% of the distance from the center 122 to the enclosure 120.

[0051] The LED filament arrangement 100 elongates along the first axis, A, and the enclosure 120 comprises a respective light exit window 125. Each light exit window 125 has a respective opening angle sector, 0n, in relation to the first axis, A, for each of the plurality of partitions 140. A light exit window 125 may be seen as an opening in the enclosure 120 allowing light transmission between a partition 140 and the outside of the enclosure 120. In other words, the LED filament light may exit the enclosure 120 via the respective light exit windows 125. Each partition 140 has a corresponding light exit window 125, through which LED filament light, both direct light from the LED filament 110 and reflected light from the diffuse reflective surfaces 135, may exit the corresponding partition 140. In other words, the LED filament light from different LED filaments 110 and partitions 140 are visible from different angles for an observer from outside the enclosure 120, while they together may provide a light distribution and light intensity to mimic / imitate a single LED filament.

[0052] In Fig. 2A, the LED filament arrangement 100 comprises a first partition 140a having a first LED filament 110a and a first light exit window 125a with a first opening angle sector, 9i, through which LED filament light from the first LED filament 110a exits the first partition 140a. The LED filament arrangement 100 comprises a second partition 140b having a second LED filament 110a and a second light exit window 125b with a second opening angle sector, 02, through which LED filament light from the second LED filament 110a exits the second partition 140a. The LED filament arrangement 100 comprises a third partition 140c having a third LED filament 110a and a third light exit window 125c with a third opening angle sector, 03, through which LED filament light from the third LED filament 110a exits the third partition 140a. The LED filament arrangement 100 comprises a fourth partition 140d having a fourth LED filament 110a and a fourth light exit window 125d with a fourth opening angle sector, 04, through which LED filament light from the fourth LED filament 110a exits the fourth partition 140a.

[0053] According to an example, each opening angle sector, 0n, may be different from the other opening angle sectors, 0n. In other words, there may be no overlap between the different opening angle sectors, 0n, of the different light exit windows 125. The light exit windows 125 may be arranged to allow LED filament light to be emitted omnidirectionally with respect to the first axis, A. Hence, the opening angle sectors, 0n, may include / cover the whole rotation around the first axis A. In Fig. 2B, the LED filament arrangement 100 comprises three LED filaments 110a, 110b, 110c and three diffuse reflective surfaces 135a, 135b, 135c, arranged in a respective partition 140a, 140, 140c. The three LED filaments 110a, 110b, 110c are arranged such that a distance, Di, between a LED filament 110 and the corresponding light exit window 125 at the same partition 140, is larger than the distance, D2, between a LED filament 110 and the corresponding reflective surface 135, in the same partition 140. In other words, in Fig. 2B, a first LED filament 110a is arranged in a first partition 140a, at a first distance, Di, perpendicular to a first axis, A, from a first light exit window 125a. Furthermore, the first LED filament 110a is arranged at a second distance, D2, perpendicular to the first axis, A, from the partitioner 130. A second LED filament 110b is arranged in a second partition 140b, at a first distance, Di, perpendicular to a first axis, A, from a second light exit window 125b. Furthermore, the second LED filament 110b is arranged at a second distance, D2, perpendicular to the first axis, A, from the partitioner 130. A third LED filament 110c is arranged in a third partition 140c, at a first distance, Di, perpendicular to a first axis, A, from a third light exit window 125c. Furthermore, the third LED filament 110c is arranged at a second distance, D2, perpendicular to the first axis, A, from the partitioner 130. In each partition 140, Di is larger than D2. It is to be understood that the first distances, Di, for each LED filament 110 may vary, i.e. Di may be different in each partition 140. Similarly, it is to be understood that the second distances, D2, for each LED filament 110 may vary, i.e. D2 may be different in each partition 140.

[0054] In Fig. 2B, the first reflective surface 135a is one straight surface. The second reflective surface 135b is a curved surface arranged near the center of the enclosure 120, and wherein the curved surface curves at least partially around the second LED filament 110b. The third reflective surface 135c consists of two right-angled surfaces arranged near the center of enclosure 120. It is to be understood that the diffuse reflective surfaces 135 may vary in size and shape.

[0055] In Fig. 2C, the LED filament arrangement 100 comprises six LED filaments 110 and six diffuse reflective surfaces 135. The partitioner 130 is shaped as an asterisk / star with six points, elongated parts, protrusions, legs or arms. The partitioner 130 and the enclosure 120 form six partitions. In each partition, there is arranged one LED filament 110 and one reflective surface 135. Each partition has a light exit window 125 with an opening angle sector, 0n. In Fig. 2C, the partitioner 130 is an at least partly light-transmissive partitioner. The partitioner 130 may comprise a light-transmissive material having a lighttransmission, T, of 5% to 30%. Hence, some LED filament light may be transmitted through the partitioner 130 and provide a further diffusive effect on the lighting distribution of the LED filament arrangement 100.

[0056] In Fig. 2C, the partitioner 130 is in thermal contact and / or in physical contact with the plurality of LED filaments 110. The partitioner 130 may comprise a thermally conductive material and be arranged to dissipate heat from the plurality of LED filaments 110 upon operation of the LED filament arrangement 100.

[0057] Fig. 3 is a schematic view of a luminaire 400 according to an exemplifying embodiment of the present invention. It should be noted that the luminaire 400 shown in Fig. 3 has several features in common with the LED filament arrangement 100 shown in Figs. 1 and 2A-2C, and it is hereby referred to Fig. 1 and 2A-2C, and the associated text(s) for an increased understanding of some of the features and / or functions of the luminaire 400. Fig. 4 illustrates a luminaire 400 connected to a lamp post. The luminaire 400 comprises a LED filament arrangement 100, according to an embodiment of the present invention, arranged inside an enclosure 120. The luminaire 400 comprises five light exit windows 125 formed by the enclosure 120, wherein three light exit windows 125 can be seen in the figure, and two cannot be seen. Each light exit window 125 has a corresponding LED filament 110 of the LED filament arrangement 100 arranged inside the enclosure, in different partitions defined by the enclosure 120 and a partitioner 130.

[0058] The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the LED filament arrangement 100 may have a different number of LED filaments, partitions and diffuse reflective surfaces than those depicted / described. Furthermore, the LED filaments 110, the enclosure 120, the partitioner 130, the diffuse reflective surfaces 135 etc., may have different shapes, dimensions and / or sizes than those depicted / described.

Claims

CLAIMS:

1. A light emitting diode, LED, filament arrangement (100) configured to provide LED filament arrangement light (105) and comprising: a plurality of LED filaments (110) configured to emit respective LED filament light (115), an at least partially light-transmissive enclosure (120), wherein the enclosure at least partially encloses the plurality of LED filaments, a partitioner (130) arranged within the enclosure, wherein the partitioner and the enclosure define a plurality of partitions (140), wherein the partitioner comprises a plurality of diffuse reflective surfaces (135) configured to reflect light by diffuse reflection, wherein at least one reflective surface of the plurality of diffuse reflective surfaces and at least one LED filament of the plurality of LED filaments are arranged in each partition, wherein: the partitioner is an at least partly light-transmissive partitioner; and the partitioner has a transmissivity in a range from 5% to 30%, wherein the plurality of LED filament comprises at least n LED filaments configured to emit a respective LED filament light, wherein 6 > n > 3, wherein the partitioner and the enclosure define n partitions, and wherein a respective LED filament of the plurality of LED filaments is arranged in a respective partition of the partitions.

2. The LED filament arrangement according to claim 1, wherein each LED filament of the plurality of LED filaments is a spiral LED filament.

3. The LED filament arrangement according to claim 1 or 2, wherein the LED filaments are configured in the partitioner such that at a viewing distance of less than 10 meters only 1 or 2 LED filaments are visible.

4. The LED filament arrangement according to any of the preceding claims, wherein the LED filament arrangement elongates along a first axis, A, and wherein the enclosure comprises a respective light exit window (125) having a respective opening angle sector, On, in relation to the first axis, A, for each of the plurality of partitions, such that the LED filament light is arranged to exit the enclosure via the light exit windows.

5. The LED filament arrangement according to claim 4, wherein at least two partitions of the plurality of partitions have a different opening angle sector, 0n.

6. The LED filament arrangement according to claim 4 or 5, wherein the light exit windows are arranged to allow LED filament light to be emitted omnidirectionally with respect to the first axis A.

7. The LED filament arrangement according to any one of claims 4 to 6, wherein each LED filament of the plurality of LED filaments is arranged at a first distance, Di, perpendicular to the first axis, A, from the respective light exit window for the respective partition and at a second distance, D2, perpendicular to the first axis, A, from the partitioner, wherein Di and D2 fulfil DI>D2.

8. The LED filament arrangement according to any one of the preceding claims, wherein the plurality of diffuse reflective surfaces comprises a diffuse reflective material having a reflectivity, R, of at least 70%.

9. The LED filament arrangement according to any one of the preceding claims, wherein the enclosure has an inner width (Wl) and the partitioner has a outer width (W2), wherein O.8<W2 / W1<1.

10. The LED filament arrangement according to any one of the preceding claims, wherein the partitioner has a cross-shape or asterisk-shape.

11. The LED filament arrangement according to any one of the preceding claims, wherein the partitioner is, at least one ofin thermal contact with the plurality of LED filaments, wherein the partitioner comprises a thermally conductive material and is arranged to dissipate heat from the plurality of LED filament upon operation of the LED filament arrangement, and in physical contact with the plurality of LED filaments.

12. The LED filament arrangement according to any one of the preceding claims, wherein at least a first part (132) of the partitioner extends from a center (122) of the enclosure to an inner surface (127) of the enclosure (120), preferably, the first part extends over at least 80% of the distance from the center (122) to the inner surface (127) of the enclosure (120).

13. A LED filament lamp, comprising: a LED filament arrangement according to any one of the preceding claims 1 to 12, wherein the enclosure is an at least partially light-transparent envelope, and a base arranged to mechanically and electrically connect the LED lamp to a socket of a luminaire.

14. A luminaire (400), comprising one of a LED filament arrangement according to any one of claims 1 to 12, and a LED filament lamp according to claim 13.

Images