An elongated flexible LED lighting device

Abstract

An elongated flexible LED lighting device (1) comprising a flexible elongated carrier (2) comprising a longitudinal carrier axis (LCA), a first major surface (10) and a second major surface (11), and a plurality of LEDs (3) configured to, in operation, emit LED light (4), each LED of the plurality of LEDs (3) comprising a longitudinal LED axis (LLA), each LED of the plurality of LEDs (3) being mechanically connected to the first major surface (10) of the flexible elongated carrier (2), and each LED of the plurality of LEDs (3) being arranged such that its respective longitudinal LED axis (LLA) extends in an angle θ with respect to the longitudinal carrier axis (LCA) of the flexible elongated carrier (2), where the angle θ is in a range from 87 to 50 degrees.

Description

[0001] An elongated flexible LED lighting device

[0002] FIELD OF THE INVENTION

[0003] The invention relates to an elongated flexible LED lighting device comprising a flexible elongated carrier with a longitudinal carrier axis, and a plurality of LEDs configured to, in operation, emit LED light, each LED of the plurality of LEDs comprising a longitudinal LED axis, and the plurality of LEDs being mechanically connected to the flexible elongated carrier. The elongated flexible LED lighting device may for instance be a LED strip or a LED filament.

[0004] The invention further relates to a luminaire and a lamp comprising such an elongated flexible LED lighting device.

[0005] BACKGROUND OF THE INVENTION

[0006] Flexible LED strips and LED filaments are two dominating LED lighting configurations. They are used in many lighting applications including non-flat designs. It is forecasted that its market size will increase with a factor 4 over the coming 5 years.

[0007] US 2019 / 0331311 Al discloses a flexible lighting strip for use in a vehicle signaling light. The flexible lighting strip comprises a multitude of LEDs. The flexible lighting strip is arranged to be bent around at least two, more preferably three linear independent axes. LEDs of at least a first group of the LEDs are inclined with respect to a longitudinal extension of the flexible lighting strip such that the surface normal of light exit surfaces of the first group of the LEDs enclose a first angle of more than 0° with the corresponding surface normal of a light emission surface of the flexible lighting strip.

[0008] US 2013 / 229796 discloses an LED bar and an LED module. The LED bar includes a long shaped substrate, a plurality of first LEDs and a second LED. Two long parallel edges of the long shaped substrate are extended along a first direction. The long shaped substrate includes a non-connecting area and a connecting area located at an end of the long shaped substrate. The first LEDs are interlaced and disposed in the non-connecting area and between the two long sides. Each first LED has a first long axis disposed along the first direction. The second LED has a second long axis disposed in the connecting area and along a second direction. The first direction and the second direction are intersected at a predetermined angle. It is desired to improve the performance of LED strips and / or LED filaments.

[0009] SUMMARY OF THE INVENTION

[0010] It is an object of the present invention to overcome this problem, and to provide an elongated flexible LED lighting device, such as for example an LED strip or an LED filament, with an improved performance.

[0011] It is a further object to provide an elongated flexible LED lighting device which may be shaped easily, and which is more reliable, and particularly with which the risk of fracture or damage to the LEDs and their mechanical and electrical connection during the shaping process is lowered.

[0012] According to a first aspect of the invention, this and other objects are achieved by means of an elongated flexible LED lighting device configured to provide, when in operation, device light and comprising a flexible elongated carrier comprising a longitudinal carrier axis, LCA, a first major surface and a second major surface opposite to said first major surface, and a plurality of LEDs configured to, in operation, emit LED light, each LED of the plurality of LEDs comprising a longitudinal LED axis, LLA, where each LED of the plurality of LEDs is mechanically connected to the first major surface of the flexible elongated carrier, and where each LED of the plurality of LEDs is arranged such that its respective longitudinal LED axis, LLA, extends at an angle 9 with respect to the longitudinal carrier axis, LCA, of the flexible elongated carrier, and where the angle 9 is in a range from 87 to 59 degrees.

[0013] Thereby, and in particular by providing that each LED of the plurality of LEDs is arranged such that its respective longitudinal LED axis, LLA, extends in an angle 9 with respect to the longitudinal carrier axis, LCA, of the flexible elongated carrier, and that the angle 9 is in a range from 87 to 59 degrees, it is ensured that when the elongated flexible LED lighting device is shaped, and in particular is arranged in a helix configuration, the longitudinal LED axis, LLA, of the LEDs is oriented in the pitch direction of the shape, and particularly the helix.

[0014] Thereby, an elongated flexible LED lighting device is provided which may be shaped easily and which is more reliable, and particularly with which the risk of fracture or damage to the LEDs and its mechanical and electrical connection during the shaping process is lowered.

[0015] Thus, an elongated flexible LED lighting device, such as for example an LED strip or an LED filament, with an improved performance is provided for. The angle 0 may be in a range from 80 to 60 degrees.

[0016] Thereby, it is ensured that when the elongated flexible LED lighting device is shaped, and in particular is arranged in a helix configuration, the longitudinal LED axis,

[0017] LLA, of the LEDs is oriented in the pitch direction of the shape, and particularly the helix, in a particularly precise manner.

[0018] The angle 9 may be in a range from 70 to 50 degrees. Alternatively, or additionally, the plurality of LEDs may be arranged in a configuration being free from further LEDs.

[0019] Thereby, it ensured that the above objects are achieved, even when shaping the elongated flexible LED lighting device in such a way that it is provided with one or more sharp bends. By a “sharp bend” is in this connection to be understood a bend comprising a bending angle of at least 80 degrees.

[0020] The angle 9 may be in a range from 87 to 70 degrees. Alternatively, or additionally, the elongated flexible LED lighting device may further comprise one or more further LEDs, the one or more further LEDs each comprising a further longitudinal LED axis,

[0021] LLB, LLB’, and the one or more further LEDs being arranged on the elongated flexible carrier such that i) their respective further longitudinal LED axis, LLB, LLB’, extends either in parallel with the longitudinal carrier axis, LCA, of the elongated flexible carrier or perpendicular to the longitudinal carrier axis, LCA, of the elongated flexible carrier, and ii) the one or more further LEDs are arranged between the LEDs of the plurality of LEDs on the elongated flexible carrier.

[0022] Thereby, it ensured that the above objects are achieved, even when shaping the elongated flexible LED lighting device in such a way that it is provided with one or more gentle bends. By a “gentle bend” is in this connection to be understood a bend comprising a bending angle of more than 45 degrees but less than 80 degrees.

[0023] The angle 0 may be constant for the LEDs of the plurality of LEDs.

[0024] Thereby, a constant light effect is obtained over the whole length of the elongated flexible LED lighting device.

[0025] The angle 0 may be varied for the LEDs of the plurality of LEDs.

[0026] Thereby, a light effect is obtained which may be varied over the length of the elongated flexible LED lighting device.

[0027] The angle 0 may be varied for the LEDs of the plurality of LEDs in such a way that the angle 0 is gradually increasing or is gradually decreasing or a combination thereof when seen in the direction of the longitudinal carrier axis, LCA, of the elongated flexible carrier, and the angle 0 may be gradually increasing or gradually decreasing across at least three neighboring LEDs.

[0028] Thereby, a light effect is obtained which may be varied over the length of the elongated flexible LED lighting device in a particularly simple and aesthetically pleasing manner.

[0029] The plurality of LEDs may comprise N LEDs, where N is an integer being at least 10, at least 20, or at least 30.

[0030] It has been found that such a number of LEDs ensure that the above objects are achieved in a particularly efficient and visually clear manner.

[0031] The plurality of LEDs, and, where provided, the one or more further LEDs, may be arranged with a spacing between neighboring LEDs measured along the longitudinal carrier axis, LCA, of the flexible elongated carrier, and the spacing may be varied.

[0032] Thereby, a light effect is obtained which may be varied over the length of the elongated flexible LED lighting device is obtained.

[0033] Alternatively, the spacing may be constant.

[0034] By providing a constant spacing, a constant light effect is obtained over the whole length of the elongated flexible LED lighting device is obtained.

[0035] Alternatively, the spacing may be in a range from 0.1 mm to 1 mm.

[0036] By providing a spacing in a range from 0.1 mm to 1 mm it is ensured that the output light of the elongated flexible LED lighting device is homogeneous over the length of the elongated flexible LED lighting device.

[0037] Alternatively, the spacing may be in the order of the cosine to the angle 9.

[0038] By providing a spacing in the order of the cosine to the angle 9, it has been found that the effect of the angle 9 chosen and the effect of the spacing chosen do not affect each other adversely.

[0039] The plurality of LEDs, and, where provided, the one or more further LEDs, may be arranged with a spacing between neighboring LEDs measured along the longitudinal carrier axis, LCA, of the flexible elongated carrier, where the spacing is varied depending on (i) the LED size and / or (ii) the angle 9 between one or both of the respective longitudinal LED axis, LLA, of the respective LED and the angle 9 between the respective further longitudinal LED axis LLB, LLB’ of the respective further LED, and the longitudinal carrier axis, LCA, of the flexible elongated carrier. By varying the spacing as described above, it has been found that the effect of the angle 0 chosen and the effect of the spacing chosen do not affect each other adversely.

[0040] The LEDs of the plurality of LEDs may comprise a mutually similar shape.

[0041] Each of the LEDs of the plurality of LEDs comprises a length, L, extending in the direction of the longitudinal LED axis, LLA, of each LED of the plurality of LEDs, a width, W, extending transverse to the length, L, and an aspect ratio, AR, defined as AR = LAV, where AR may be at least 1.2 or at least two.

[0042] Thereby, it is ensured that when the elongated flexible LED lighting device is shaped, and in particular is arranged in a helix configuration, the longitudinal LED axis, LLA, of the LEDs is oriented in the pitch direction of the shape, and particularly the helix, in a particularly precise manner.

[0043] The elongated flexible LED lighting device may further comprise electrical circuitry configured to provide the plurality of LEDs, and, where provided, the one or more further LEDs, with a current, where the electrical circuitry is arranged on the elongated carrier, where the electrical circuitry for each LED of the plurality of LEDs, and, where provided, the one or more further LEDs, comprises an anode and a cathode, and where each anode and its associated respective cathode of the electrical circuitry are arranged such that a virtual, straight line, which spans the shortest distance between the anode and the cathode of each LED, extends in an angle <p with respect to the longitudinal carrier axis, LCA, of the flexible elongated carrier, and where the angle <p is different from 90 degrees.

[0044] Alternatively, or additionally, at least the anodes and the cathodes of the electrical circuitry may be arranged such as to extend in a plane, P, the plane, P, extending an angle <p with respect to the longitudinal carrier axis, LCA, of the flexible elongated carrier.

[0045] Thereby, an elongated flexible LED lighting device is provided which may be shaped easily and which is more reliable, and particularly with which the risk of fracture or damage to not only the LEDs but in particular also the electrical circuitry during the shaping process is lowered.

[0046] Thus, an elongated flexible LED lighting device, such as for example an LED strip or an LED filament, with an even further improved performance is provided for.

[0047] The angle <p may be in a range from 87 to 50 degrees, or in a range from 80 to 60 degrees, or in a range from 70 to 50 degrees, or in a range from 87 to 70 degrees. By providing the angle <p with a size being similar to or the same as the angle 0, it has been found that the risk of fracture or damage to the electrical circuitry during the shaping process becomes particularly low.

[0048] The elongated flexible LED lighting device may further comprise an elongated flexible encapsulant covering at least the plurality of LEDs, and, where provided, the one or more further LEDs.

[0049] Thereby, the above-described effects relating to the shaping and the reliability or performance improvement of the elongated flexible LED lighting device is further improved.

[0050] The elongated flexible LED lighting device may further comprise a further elongated flexible encapsulant provided on the second major surface of the elongated flexible carrier opposite to the first major surface of the elongated flexible carrier on which the plurality of LEDs is arranged.

[0051] Thereby, the above-described effects relating to the shaping and the reliability or performance improvement of the elongated flexible LED lighting device is further improved.

[0052] The further flexible encapsulant may be light-transmissive, translucent, or transparent.

[0053] The elongated flexible encapsulant, and optionally the further elongated flexible encapsulant, may comprise a light scattering material for scattering at least part of the LED light into scattered light.

[0054] Alternatively, or additionally, the elongated flexible encapsulant, and optionally the further elongated flexible encapsulant, may comprise a luminescent material for converting at least part of the LED light into converted light.

[0055] The invention further relates to a luminaire or a lamp comprising an elongated flexible LED lighting device according to the invention.

[0056] It is noted that the invention relates to all possible combinations of features recited in the claims.

[0057] BRIEF DESCRIPTION OF THE DRAWINGS

[0058] 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.

[0059] Fig. 1 shows a schematical top view of an elongated flexible LED lighting device according to an embodiment of the invention. Fig. 2 shows a schematical side view of the elongated flexible LED lighting device according to Fig. 1.

[0060] Fig. 3 shows a schematical top view of an elongated flexible LED lighting device according to another embodiment of the invention.

[0061] Fig. 4 schematically shows another LED filaments achievable with an elongated flexible LED lighting device according to the invention and being helix shaped.

[0062] Fig. 5 shows a cross-sectional side view of a luminaire comprising an elongated flexible LED lighting device according to the invention.

[0063] As illustrated in the figures, the sizes of layers and regions are exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of embodiments of the present invention. Like reference numerals refer to like elements throughout.

[0064] DETAILED DESCRIPTION

[0065] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

[0066] Fig. 1 shows a schematical top view of an elongated flexible LED lighting device 1 according to an embodiment of the invention, while Fig. 2 shows a schematical side view of the elongated flexible LED lighting device 1.

[0067] Generally, and irrespective of the embodiment, the elongated flexible LED lighting device 1 is configured to, in operation, provide device light and comprises a flexible elongated carrier 2 and a plurality of LEDs 3. The device light may be white light. The white light may have a correlated color temperature in a range from 1800 to 6500K and a CRI of at least 80.

[0068] The flexible elongated carrier 2 comprises a longitudinal carrier axis LCA, a first major surface 10 (cf. Figs. 1 and 2) and a second major surface 11 (cf. Fig. 2). The flexible elongated carrier 2 may be a substrate or a printed circuit board. The flexible elongated carrier 2 may be made of a suitable polymer.

[0069] The plurality of LEDs 3 is configured to, in operation, emit LED light 4 (cf. Fig. 2). The plurality of LEDs may comprise RGB LEDs and / or white phosphor converted LEDs. Each LED of the plurality of LEDs 3 comprises a longitudinal LED axis LLA, a length L extending in parallel with the longitudinal LED axis LLA, a width W extending perpendicular or transverse to the length L and a height H (cf Fig. 2) extending perpendicular to both the length L and the width W. The plurality of LEDs 3 is mechanically connected to the flexible elongated carrier 2. The plurality of LEDs 3 is arranged on the first major surface 10 of the elongated flexible carrier 2. The plurality of LEDs 3 comprises N LEDs, N being an integer being at least 10, at least 20, or at least 30.

[0070] Each LED of the plurality of LEDs 3 is arranged such that its respective longitudinal LED axis LLA extend in an angle 0 with respect to the longitudinal carrier axis LCA of the flexible elongated carrier 2. The angle 9 is in a range from 45 to 89 degrees, such as in a range from 87 to 50 degrees. The angle 9 may also be in a range from 80 to 60 degrees. In the embodiment shown in Figs. 1 and 2, the plurality of LEDs 3 is arranged in a configuration being free from any further LEDs. That is, the elongated flexible LED lighting device 1 exclusively comprises the plurality of LEDs 3. In such a case, the angle 0 may be chosen to be in a range from 70 to 50 degrees.

[0071] The angle 0 may be constant for all of the LEDs of the plurality of LEDs 3. Alternatively, the angle 0 is varied or may be varying for the LEDs of the plurality of LEDs 3. In the latter case, the angle 0 may for instance be varied or varying in such a way that the angle 0 is gradually increasing or is gradually decreasing or a combination thereof when seen in the direction of the longitudinal carrier axis LCA of the elongated flexible carrier 2. For instance, the angle 0 may be gradually increasing or gradually decreasing across at least three neighboring LEDs, or at least five neighboring LEDs, of the plurality of LEDs 3.

[0072] Each of the LEDs of the plurality of LEDs 3 further comprise an aspect ratio AR. The aspect ratio AR is defined as AR = LAV. The aspect ratio AR may be chosen such that AR > 1.2 or even AR > 2.

[0073] The plurality of LEDs 3 is further arranged with a spacing 6 between neighboring LEDs. The spacing 6 is measured as the shortest distance between two points on neighboring LEDs, that is the shortest distance spanning the open area between neighboring LEDs. The spacing 6 may as shown on Figs. 1 and 2 be constant over the longitudinal extension of the carrier 2. Alternatively, the spacing 6 may be varied or varying over the longitudinal extension of the carrier 2. For instance, the spacing 6 may be varied depending on the LED size. Alternatively, or additionally, the spacing 6 may be varied depending on the angle 0 between the respective longitudinal LED axis LLA of the respective LED and the longitudinal carrier axis LCA of the flexible elongated carrier 2. For instance, the spacing 6 may be chosen to be between 0.1 mm and 1 mm. The spacing 6 may also be chosen to be in the order of the cosine to the angle 0.

[0074] The plurality of LEDs 3 may further be arranged with a pitch T between neighboring LEDs. The pitch T is measured as the center-to-center distance between two neighboring LEDs. The pitch T may, as shown on Figs. 1 and 2, be constant over the longitudinal extension of the carrier 2. Alternatively, the pitch T may be varied or varying over the longitudinal extension of the carrier 2.

[0075] Referring specifically to Fig. 1, the elongated flexible LED lighting device 1 may further comprise electrical circuitry 7 configured to provide the plurality of LEDs 3 with electrical energy. The electrical circuitry 7 may be arranged on or in the elongated carrier 2. In other words, the plurality of LEDs 3 may also be electrically connected to the elongated carrier 2. For each LED of the plurality of LEDs 3, the electrical circuitry 7 comprises an anode 12 and a cathode 13. For each LED of the plurality of LEDs 3, the associated anode 12 and cathode 13 of the electrical circuitry 7 are arranged such that a virtual, straight line 18 (cf. Fig. 1) spans the shortest distance between the anode 12 and the cathode 13. In other words, a virtual, straight line 18 (cf. Fig. 1) spans the shortest distance between the anode 12 and the cathode 13 of each LED of the plurality of LEDs 3. The anode 12 and the cathode 13 of each LED of the plurality of LEDs 3 are further arranged such that the corresponding virtual, straight line 18 extends in an angle <p with respect to the longitudinal carrier axis LCA of the flexible elongated carrier 2. For at least some, and particularly for each, LED of the plurality of LEDs 3, at least the anodes 12 and the cathodes 13 of the electrical circuitry 7 are arranged such as to extend in a plane P. The plane P extends an angle <p with respect to the longitudinal carrier axis LCA of the flexible elongated carrier 2. The angle <p may be similar to or equal to the angle 0. The angle <p may for instance be chosen to be between 87 and 50 degrees, or between 80 and 60 degrees, or between 70 and 50 degrees, or between 87 and 70 degrees. In any event, the angle <p may be different from 90 degrees.

[0076] Referring specifically to Fig. 2, the elongated flexible LED lighting device 1 may further comprise an optional elongated flexible encapsulant 8. The elongated flexible encapsulant 8 is arranged such as to cover at least the plurality of LEDs 3. The elongated flexible encapsulant 8 may further be arranged such as to cover at least a part of the elongated flexible carrier 2. The elongated flexible encapsulant 8 is arranged on the first major surface 10 of the elongated flexible carrier 2. The elongated flexible encapsulant 8 may comprise a light scattering material 15 for scattering at least part of the LED light 4. Alternatively, or additionally, the elongated flexible encapsulant 8 may comprise a luminescent material 16 for converting at least a part of the LED light 4 into converted light 17.

[0077] Referring still to Fig. 2, the elongated flexible LED lighting device 1 may also comprise an optional further elongated flexible encapsulant 9. The further elongated flexible encapsulant 9 may be arranged such as to cover at least a part of the elongated flexible carrier 2. The further elongated flexible encapsulant 9 is provided on the second major surface 11 of the elongated flexible carrier 2. The further elongated flexible encapsulant 9 may be light- transmissive, translucent, or transparent. The further elongated flexible encapsulant 9 may comprise a light scattering material for scattering at least part of the LED light 4. Alternatively, or additionally, the further elongated flexible encapsulant 9 may comprise a luminescent material for converting at least a part of the LED light 4 into converted light.

[0078] Turning now to Fig. 3, a schematical top view of an elongated flexible LED lighting device 100 according to another embodiment of the invention is shown. The elongated flexible LED lighting device 100 differs from the elongated flexible LED lighting device 1 described above in relation to Figs. 1 and 2 in virtue of the following features.

[0079] The angle 0 is chosen to be between 87 and 70 degrees. The elongated flexible LED lighting device 100 comprises one or more further LEDs 5, 5’. The one or more further LEDs 5, 5’ each comprise a further longitudinal LED axis LLB, LLB’, respectively. The one or more further LEDs 5, 5’ are arranged on and mechanically connected to the elongated flexible carrier 2.

[0080] The one or more further LEDs 5 are more specifically arranged on the elongated flexible carrier 2 in such a way that their respective further longitudinal LED axis B extends in parallel with the longitudinal carrier axis LCA of the elongated flexible carrier 2. The one or more further LEDs 5’ are more specifically arranged on the elongated flexible carrier 2 in such a way that their respective further longitudinal LED axis LLB’ extends perpendicular to the longitudinal carrier axis LCA of the elongated flexible carrier 2. Furthermore, both the one or more further LEDs 5 and the one or more further LEDs 5’ are arranged between the LEDs of the plurality of LEDs 3.

[0081] The plurality of LEDs 3 and the one or more further LEDs 5, 5’ are arranged with a spacing 6 and 6’, respectively, between neighboring LEDs. The spacing 6, 6’ may be constant. As shown on Fig. 3, however, the spacing 6, 6’ is varied or varying over the longitudinal extension of the carrier 2. For instance, the spacing 6, 6’ may be varied depending on the LED size and / or depending on the angle 0 between the respective longitudinal LED axis LLA of the respective LED 3 and the longitudinal carrier axis LCA of the flexible elongated carrier 2 and / or depending on the angle 9 between the respective further longitudinal LED axis LLB; LLB’ of the respective further LED 5, 5’ and the longitudinal carrier axis LCA of the flexible elongated carrier 2. For instance, the spacing 6, 6’ may be chosen to be between 0.1 mm and 1 mm. The spacing 6, 6’ may also be chosen to be in the order of the cosine to the angle 9. The spacing 6, 6’ shown on Fig. 3 is varied or varying over the longitudinal extension of the carrier 2. In the example illustrated in Fig. 3, the spacing 6, 6’ is increased over the longitudinal extension of the carrier 2, when seen from left to right on Fig. 3, such that the spacing 6’ is larger than the spacing 6. Alternatively, the spacing 6, 6’ may be decreased over the longitudinal extension of the carrier 2, such that the spacing 6’ would be smaller than the spacing 6. A combination of an increasing and a decreasing spacing 6, 6’ over the longitudinal extension of the carrier 2 is also feasible.

[0082] The plurality of LEDs 3 and the one or more further LEDs 5, 5’ may further be arranged with a pitch T, T’ between neighboring LEDs. The pitch T, T’ is measured as the center-to-center distance between two neighboring LEDs, 3, 5, 5’. The pitch T may be varied or varying over the longitudinal extension of the carrier 2. In the example illustrated in Fig. 3, the pitch T, T’ is increased over the longitudinal extension of the carrier 2, when seen from left to right on Fig. 3, such that the pitch T’ is larger than the pitch T. Alternatively, the pitch T, T’ may be decreased over the longitudinal extension of the carrier 2, such that the pitch T’ would be smaller than the pitch T. A combination of an increasing and a decreasing pitch T, T' over the longitudinal extension of the carrier 2 is also feasible.

[0083] The electrical circuitry 7 may further be configured to provide the one or more further LEDs 5, 5’ with electrical energy. Thus, the one or more further LEDs 5, 5’ may be electrically connected to the elongated carrier 2. The electrical circuitry 7 may for each of the one or more further LEDs 5, 5’ comprise an anode 12 and a cathode 13.

[0084] The elongated flexible encapsulant 8 may further be covering the one or more further LEDs 5, 5’.

[0085] Fig. 4 schematically shows a helix-shaped LED filament achievable with an elongated flexible LED lighting device 1 according to the invention. Elongated flexible LED lighting devices 1 according to the invention are particularly suitable for providing high performance helix-shaped LED filaments. However, elongated flexible LED lighting devices 1 according to the invention may also be shaped into a wide variety of other feasible shapes, such as, but not limited to, spiral-shaped, meandering, twisted, and combinations thereof. Finally, Fig. 5 shows an exemplary lamp 20 comprising an elongated flexible LED lighting device 1 according to any embodiment of the invention. In the embodiment shown, the elongated flexible LED lighting device 1 is a substantially straight LED filament. The elongated flexible LED lighting device 1 of such a lamp may in other embodiments be an elongated flexible LED lighting device 1 with another shape, such as, but not limited to, spiral-shaped, helix-shaped (cf. for example Fig. 5), meandering, twisted, flat and combinations thereof.

[0086] The lamp 20 further comprises a driver or controller 25 configured for controlling the LEDs 3, 5, 5’ of the elongated flexible LED lighting device 1. The controller 25 is configured to power the LEDs 3, 5, 5’ via the electrical circuitry 7 of the elongated flexible LED lighting device 1. The controller 25 may further be configured for controlling at least one of the CCT of the LED light 4 and the CRI of the LED light 4. The controller 25 may also be configured for controlling other parameters related to the LEDs 3, 5, 5’ and the LED light 4.

[0087] The lamp 20 further comprises an envelope 21 at least partially enveloping the at least one elongated flexible LED lighting device 1. The lamp 20 further comprises a cap 22. As shown in Fig. 5, the controller 25 is arranged within the envelope 21. When comprising a cap 22, the controller 25 may also be arranged inside the cap 22 such that it is hidden from view. The lamp 20 further comprises threading 23 for connection to a socket and a terminal 24 for connection to a source of electrical energy.

[0088] The envelope 21 of the lamp 20 may further and optionally be provided with a coating 26, such as a reflective coating, covering at least a part of the envelope 21.

[0089] 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.

[0090] Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

CLAIMS1. An elongated flexible LED lighting device (1) providing, when in operation, device light and comprising: a flexible elongated carrier (2) comprising a longitudinal carrier axis (LCA), a first major surface (10) and a second major surface (11) opposite to said first major surface, and a plurality of LEDs (3) configured to, in operation, emit LED light (4), each LED of the plurality of LEDs comprising a longitudinal LED axis (LLA), wherein each LED of the plurality of LEDs (3) is mechanically connected to the first major surface (10) of the flexible elongated carrier (2), and wherein each LED of the plurality of LEDs (3) is arranged such that its respective longitudinal LED axis (LLA) extends at an angle 0 with respect to the longitudinal carrier axis (LCA) of the flexible elongated carrier (2), and wherein the angle 9 is in a range from 87 to 50 degrees, and wherein the plurality of LEDs (3) is arranged in a configuration being free from further LEDs, the elongated flexible LED lighting device (1) exclusively comprises the plurality of LEDs (3).

2. An elongated flexible LED lighting device according to claim 1, wherein the angle 9 is in a range from 80 to 60 degrees.

3. An elongated flexible LED lighting device according to claim 1, wherein the angle 0 is in a range from 70 to 50 degrees.

4. An elongated flexible LED lighting device according to claim 1, wherein one or both of the following applies: the angle 0 is in a range from 87 to 70 degrees, and the elongated flexible LED lighting device (1) further comprises one or more further LEDs (5; 5’), the one or more further LEDs each comprising a further longitudinal LED axis (LLB; LLB’) and the one or more further LEDs being arranged on the elongated flexible carrier (2) such that i) their respective further longitudinal LED axis (LLB, LLB’)extends either in parallel with the longitudinal carrier axis (LCA) of the elongated flexible carrier or perpendicular to the longitudinal carrier axis (LCA) of the elongated flexible carrier (2), and ii) the one or more further LEDs (5; 5’) are arranged between the LEDs of the plurality of LEDs (3) on the elongated flexible carrier (2).

5. An elongated flexible LED lighting device according to any one of the above claims, wherein the angle 0 is constant for the LEDs of the plurality of LEDs (3), or wherein the angle 9 is varied for the LEDs of the plurality of LEDs (3).

6. An elongated flexible LED lighting device according to any one of the above claims, wherein the angle 9 is varied for the LEDs of the plurality of LEDs (3) in such a way that the angle 9 is gradually increasing or is gradually decreasing or a combination thereof when seen in the direction of the longitudinal carrier axis (LCA) of the elongated flexible carrier (2), and wherein the angle 9 is gradually increasing or gradually decreasing across at least three neighboring LEDs.

7. An elongated flexible LED lighting device according to any one of the above claims, wherein the plurality of LEDs (3) comprises N LEDs, and wherein N is an integer being at least 10, at least 20, or at least 30.

8. An elongated flexible LED lighting device according to any one of the above claims, wherein the plurality of LEDs (3), and, where provided, the one or more further LEDs (5; 5’), are arranged with a spacing (6; 6’) between neighboring LEDs measured along the longitudinal carrier axis (LCA) of the flexible elongated carrier (2), and wherein the spacing (6; 6’) is varied.

9. An elongated flexible LED lighting device according to claim 5, wherein the plurality of LEDs (3), and, where provided, the one or more further LEDs (5; 5’), are arranged with a spacing (6; 6’) between neighboring LEDs measured along the longitudinal carrier axis (LCA) of the flexible elongated carrier (2), and wherein the spacing (6; 6’) is varied depending on (i) the LED size and / or (ii) angle 9 between the longitudinal carrier axis (LCA) of the flexible elongated carrier (2) and one or both of the respective longitudinalLED axis (LLA) of the respective LED (3) and the angle 9 between a respective further longitudinal LED axis (LLB; LLB’) of the respective further LED (5; 5’).

10. An elongated flexible LED lighting device according to any one of the above claims, wherein each of the LEDs of the plurality of LEDs (3) comprise a length (L) extending in the direction of the longitudinal LED axis (LLA) of each LED of the plurality of LEDs, a width (W) extending transverse to the length (L) and an aspect ratio (AR) defined as AR = LAV, and wherein AR is at least 1.2.

11. An elongated flexible LED lighting device according to any one of the above claims, and further comprising electrical circuitry (7) configured to provide the plurality of LEDs (3), and, where provided, the one or more further LEDs (5; 5’), with a current, wherein the electrical circuitry (7) is arranged on the elongated carrier (2), wherein the electrical circuitry (7) for each LED of the plurality of LEDs (3), and, where provided, the one or more further LEDs (5; 5’), comprise an anode (12) and a cathode (13), and wherein each anode (12) and its associated respective cathode (13) of the electrical circuitry are arranged such that a virtual, straight line (18), which spans the shortest distance between said anode and said cathode of each LED, extends in an angle <p with respect to the longitudinal carrier axis (LCA) of the flexible elongated carrier (2); and wherein <p is 90 degrees.

12. An elongated flexible LED lighting device according to claim 11, wherein the angle <p is in a range from 87 to 50 degrees, or in a range from 80 to 60 degrees, or in a range from 70 to 50 degrees, or in a range from 87 to 70 degrees.

13. An elongated flexible LED lighting device according to any one of the above claims, wherein the elongated flexible LED lighting device further comprises: an elongated flexible encapsulant (8) covering at least the plurality of LEDs (3), and, where provided, the one or more further LEDs (5; 5’), and optionally a further elongated flexible encapsulant (9) provided on the second major surface (11) of the elongated flexible carrier (2) opposite to the first major surface (10) of the elongated flexible carrier on which the plurality of LEDs (3) is arranged.

14. An elongated flexible LED lighting device according to claim 13, wherein the elongated flexible encapsulant (8), and optionally the further elongated flexible encapsulant (9), comprises one or both of (i) a light scattering material (15) for scattering at least part of said LED light (4) into scattered light (19) and (ii) a luminescent material (16) for converting at least part of said LED light (4) into converted light (17).

15. A luminaire or a lamp (20) comprising an elongated flexible LED lighting device (1) according to any one of the above claims.

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