Ultra-efficient color tunable lamp

Abstract

The present invention relates a light emitting diode (LED) filament lamp (100) having a longitudinal extension along a central axis X, the LED filament lamp (100) comprising: a white LED filament arrangement (101) comprising at least one white LED filament (110), configured to, in operation, emit white light having a white light emission profile having a first emission angle relative the central axis; an RGB LED arrangement (102) comprising at least one RGB LED (111), configured to, in operation, emit colored light having a RGB light emission profile having a second emission angle relative the central axis; a transparent envelope (104) at least partly enclosing the white LED filament arrangement (101) and the RGB LED arrangement (102), and a connector (105) for electrically and mechanically connecting the LED filament lamp (100) to a socket of a luminaire, wherein the white light emission profile matches the RGB light emission profile.

Description

[0001] Ultra-efficient color tunable lamp

[0002] FIELD OF THE INVENTION

[0003] The present invention generally relates to a light emitting diode, LED, filament lamp. More specifically, the present invention relates to a LED filament lamp comprising both white light filaments and RGB LEDs for providing color tunable light and a high energy efficiency.

[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.

[0006] Color tunable LED lamps are also well known for their great capabilities. However, the energy efficiency of color tunable LED lamps is substantially lower compared to ordinary LED filament lamps. To date, color tunable LED filaments lamps are often marked as energy efficiency class F, i.e. >85 %. Currently, ordinary LED filaments are among the LED types with the highest efficiency. Values of around 230 LPW can be obtained for white LEDs in the range of 2700-4000 K. Large LED efficiency improvements, suitable for these lamp applications are not to be expected in a near future. Therefore, lamps designed using LEDs must be extremely efficient, with optical and electrical efficiency typically >95 % to be rated as an energy efficiency class A lamp. Color mixing in color tunable LED lamps is usually done by diffusing the light generated by the different color sources, e.g. by letting the light pass through a diffuse outer envelope. A very distinct drawback of this is the loss of efficiency. Typical energy efficiency values of such diffuse outer envelopes are in the range of 80-90 %. This is not sufficient when aiming at the higher energy efficiency classes.

[0007] Therefore, there is a need to provide an improved color tunable LED filament lamp with consideration to energy efficiency. WO 2021 / 018646 discloses a LED filament including a linear array of LEDs arranged on a carrier substrate, wherein the linear array is divided into two separate longitudinal sections, a first longitudinal section including only LEDs configured to emit white light, and a second longitudinal section including only LEDs configured to emit color controllable light. The present invention suggests confining the color LEDs to the second longitudinal section of the array, so that the first longitudinal section of the array is capable of emitting homogenous white light of a color temperature in the range of the LEDs in that section.

[0008] SUMMARY OF THE INVENTION

[0009] Consequently, the present invention is aimed on solving the problems identified above. To this end, the present invention provides a light emitting diode (LED) filament lamp having a longitudinal extension along a central axis. The LED filament lamp comprises a white LED filament arrangement comprising at least one white LED filament. The at least one white LED filament is configured to, in operation, emit white light having a white light emission profile having a first emission angle relative the central axis. The white LED filament arrangement may follow a contour of an internal shape of a transparent envelope. Alternatively, the white LED filament arrangement have a special angular position.

[0010] The LED filament lamp further comprises an RGB LED arrangement comprising at least one RGB LED. The at least one RGB LED is configured to, in operation, emit colored light, having a RGB light emission profile having a second emission angle relative the central axis. The RGB LED arrangement may be a package mounted on a PCB. In the context of the present invention the RGB LED arrangement is different from a LED filament.

[0011] The white light emission profile matches the RGB light emission profile. The white light emission profile and the RGB light emission profile are combined in a joint emission profile. Since the LED filament lamp enables a joint emission profile, color mixing at a certain distance from the light sources is enabled without the need of a color mixing element, such as e.g. a diffuse envelope.

[0012] The LED filament lamp further comprises a transparent envelope at least partly enclosing the white LED filament arrangement and the RGB LED arrangement. Therefore, in contrast to prior art where the envelope usually is diffuse, it is sufficient for the white light and the colored light to be mixed at a larger distance. For example, it is sufficient for the white light and the colored light to be mixed at a distance of 10-15 cm from the light sources. This way, color inhomogeneity still exists at the location of the envelope. However, since it is a transparent envelope, the inhomogeneities are not visible. At the distance where a lamp shade may be present, the colors are sufficiently mixed and illuminate the lamp shade homogeneously.

[0013] The use of a transparent envelope enables a higher lumen efficiency, which in particular is beneficial for the white light. In case the color mixing of the RGB LED arrangement is done before the light exits from the LED filament lamp this requires a diffusor to be added to the envelope. This goes at the expense of the optical efficiency. In the present invention the optical efficiency is held at 99% due to the absence of a diffusor in the envelope and this raises the efficiency in lumen per watt (LPW or Im / W) with about 10%.

[0014] The LED filament lamp further comprises a connector for electrically and mechanically connecting the LED filament lamp to a socket of a luminaire.

[0015] The RGB LED arrangement according to the present invention may further comprise a printed circuit board (PCB) for carrying the at least one RGB LED. The PCB may be arranged at a second angle in relation to the central axis. In such an embodiment, the second angle is equal to the second emission angle. When the RGB LEDs are attached to a PCB, the RGB light emission profile may easily be adjusted by tilting the PCB. Provided that the second angle is adjusted such that it is the same as the first emission angle, the RGB light emission profile will coincide with the white light emission profile and form a joint emission profile.

[0016] Further, the RGB LED arrangement may comprise an optical element arranged on top of the at least one RGB LED. According to such an embodiment, the colored light emitted through the optical element has the RGB light emission profile having the second emission angle in relation to the central axis. The optical element may for example be a prism or another optical structure. Having such an optical element may be particularly advantageous because it can provide a second emission angle that coincides with the first emission angle, forming a joint emission profile without having to tilt the PCB such that the second angle is equal to the second emission angle.

[0017] The at least one white LED filament comprised in the white LED filament arrangement may be linear. Thereby, the relation between the filaments and the central axis may be such that there is a filament angle y between the filaments and the central axis. In such an embodiment, the at least one filament may be attached to the carrier in different ways, such that the filament angle y may vary from 0° - 180°. Alternatively, the white LED filament arrangement may comprise at least one white LED filament, wherein the at least one white LED filament is divided into segments. In particular, the white LED filament may comprise a first and a second segment. The first segment may have a length LI, and the second segment may have a length L2. The first segment and the second segment may be arranged in a non-linear configuration, such that the first segment has a first segment angle y and the second segment has a second segment angle a relative to the central axis. The first segment angle y and second segment angle a may be same or different. The shape of the white LED filament arrangement in this particular embodiment may for example be formed as a diamond. However, the white LED filament arrangement may also be formed as a triangle, a square or another geometrical shape. An advantage of such a particular embodiment is that the first and second segment of the at least one white LED filament, forming the specific shape, may be designed in different ways to change the emission profile of the white light. For example, the lengths LI and L2 may be same (L1=L2) or different (LI L2), and thereby the shape of the LED filament arrangement can be changed. Another way to vary the shape of the white LED filament may be to change the first and second filament angle y and a.

[0018] The white LED filament arrangement may comprise a plurality of white LED filaments, and the RGB LED arrangement may comprise a plurality of RGB LEDs. In such an embodiment, each RGB LED may be configured to be arranged between two white LED filaments. Thereby, the white LED filament arrangement and the RGB LED arrangement may form a single light source with a structure of different geometrical shapes, such as for example square, hexagonal, octagonal or any other geometrical shape. The advantage of being able to design the light source of the LED filament lamp in different geometrical shapes is that in such a way, the white light emission profile and the RGB light emission profile can be adjusted thereafter. Thus, the joint emission profile may also indirectly be adjusted.

[0019] In another particular embodiment of the LED filament lamp, the RGB LED arrangement may comprise a first set of RGB LEDs and a second set of RGB LEDs. Each RGB LED in the first set of RGB LEDs may be arranged between the first segments of the white LED filaments, and each RGB LED in the second set of the RGB LEDs may be arranged between the second segments of the white LED filaments. Such an embodiment offers the advantage of providing a joint emission profile having a particular shape, e.g. a diamond shape. Alternatively, the RGB LED arrangement may be encircled by the white LED filament arrangement. In such an embodiment, the RGB LEDs are arranged between the central axis and the white LED filaments, while the white LED filaments are arranged between the RGB LED arrangement and the transparent envelope.

[0020] As mentioned above, the LED filament lamp further comprises a transparent envelope. The transparent envelope may be closed and may contain vacuum. Alternatively, the transparent envelope may be filled with helium (He) gas. By filling the transparent envelope with He gas, the cooling of the at least one white LED filament and the at least one RGB LED is facilitated. The transparent envelope may also contain any other gas which would facilitate cooling, increase the energy efficiency, or in any other way improve the performance of the LED filament lamp.

[0021] The color temperature of the at least one white LED filament may by example be in the range of 2700 K - 5000 K. This range comprise the color temperatures commonly used in applications of which the invention is intended. Alternatively or additionally, the color temperature of the at least one white LED filament may by example be in the range of 1800 K-4000K, 2200K-6500K or 2700K-6500K.

[0022] The LED filament lamp according to the present invention may further comprise a carrier extending along the central axis of the LED filament lamp. The carrier may have a first end portion and a second end portion. The white LED filament arrangement or the RGB LED arrangement or a combination thereof may be connected to the second end portion of the carrier, and thus held up by the carrier. The first end portion of the carrier may be connected to a connector.

[0023] Alternatively, the white LED filament arrangement may be connected to the second end portion of the carrier, while the RGB LED arrangement is connected to the first end portion of the carrier. Thus, the light source for white light respectively the light source for colored light are located on different places. The RGB LEDs may be attached to a PCB comprised in the RGB LED arrangement. The PCB may further comprise electronics to enable the RGB to function. Thus an advantage of having the RGB LED arrangement connected to the first end portion of the carrier is that the PCB electronics can be enclosed within the connector.

[0024] Further, in an embodiment as described above where the white LED filament arrangement and the RGB LED arrangement form a single geometrical structure, such a structure may be connected to the second end portion of the carrier. In such an embodiment, the PCB electronics may be placed inside the structure formed by the white LED filament arrangement and the RGB LED arrangement. Thus, the PCB electronics may not be visible. Placing the PCB electronics inside such a structure and thereby inside the transparent envelope or bulb, is advantageous because less wires have to enter the transparent envelope or bulb. Normally, a LED filament lamp with a transparent envelope or bulb can only be designed such that 4 or less wires enter through the transparent envelope or bulb. Thereby, in the present invention only 3 wires would be free to use for the RGB LED arrangement. By placing the PCB electronics or part of the PCB electronics inside the transparent envelope or bulb the number of wires to use for the RGB LED arrangement may be increased.

[0025] Further, the LED filament lamp may also comprise a controller configured, in operation, to control the white LED filament light and / or the RGB light, thereby enabling color tuning of the light emitted from the LED filament lamp.

[0026] It is noted that the invention relates to all possible combinations of features recited in the claims. 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. 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.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Fig. la schematically shows a LED filament lamp according to an exemplifying embodiment of the present invention;

[0029] Fig lb shows Fig. la turned 30°;

[0030] Fig. 2a schematically shows a LED filament lamp according to another exemplifying embodiment of the present invention;

[0031] Fig 2b shows Fig. 2a turned 30°;

[0032] Fig 2c shows a perspective view of a segmented white LED filament arrangement;

[0033] Fig. 3a schematically shows the LED filament lamp according to another exemplifying embodiment of the present invention;

[0034] Fig. 3b shows Fig. 3a turned 30°;

[0035] Fig 3c shows a perspective view of Fig. 3a;

[0036] Figs. 3d-3f schematically show top views of the white LED filament arrangement and the RGB LED arrangement in different geometrical shapes; Fig. 4a shows a LED filament lamp according to another exemplifying embodiment of the present invention;

[0037] Fig. 4b shows Fig. 4a turned 30°.

[0038] DETAILED DESCRIPTION

[0039] 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.

[0040] Fig la shows a LED filament lamp 100 according to the present invention. The LED filament lamp 100 has a longitudinal extension along a central axis X. The LED filament lamp 100 comprise a white LED filament arrangement 101 comprising six white LED filaments 110. Each of six white LED filament 110 is configured to, in operation, emit white light having a white light emission profile having a first emission angle relative to the central axis. The six white LED filaments 110 comprised in the white LED filament arrangement 101 are linear. Thereby, the relation between the filaments 110 and the central axis X is such that there is a filament angle y between the filaments 110 and the central axis X. The filament angle y is equal to the first emission angle in this particular embodiment.

[0041] The LED filament lamp 100 further comprises a RGB LED arrangement 102 comprising six RGB LEDs 111. Each of six RGB LEDs is configured to, in operation, emit colored light having a RGB light emission profile having a second emission angle relative the central axis X. The white light emission profile matches the RGB light emission profile, and the profiles are combined in a joint emission profile. Since the LED filament lamp enables a joint emission profile, color mixing at a certain distance from the light sources is enabled without the need of a color mixing element, such as a diffuse envelope or diffuse outer bulb.

[0042] The LED filament lamp in Fig. la further comprises a carrier 106 having a first end portion 112 and a second end portion 113, which extends along the central axis X of the LED filament lamp 100. The white LED filament arrangement 101 is connected to the second end portion 113 of the carrier 106 and is thus held up by the carrier 106. The RGB LED arrangement 102 is connected to the first end portion 112 of the carrier 106. The first end portion 112 of the carrier is also connected to a connector 105. The LED filament lamp 100 further comprise a transparent envelope 104 enclosing the white LED filament arrangement 101 and the RGB LED arrangement 102. The transparent envelope 104 is fully clear, such that it affects the energy efficiency of the lamp 100 with the minimal impact. The transparent envelope 104 either contains vacuum or is filled with helium (He) gas. By filling the transparent envelope 104 with He gas, the cooling of the at least one white LED filament 110 and the at least one RGB LED 111 is facilitated.

[0043] The RGB LED arrangement 102 further comprise PCBs 103 for carrying the RGB LEDs 102. The PCBs 103 are arranged at a second angle in relation to the central axis X. In the embodiment shown in Fig. la, the second angle is equal to the second emission angle. By attaching the RGB LEDs 111 to a PCB 103, the RGB light emission profile may easily be adjusted by tilting the PCB 103. Provided that the second angle is adjusted in conjunction with the first emission angle, the second emission profile and the first emission profile will coincide and form ajoint emission profile.

[0044] The use of a transparent envelope enables a higher lumen efficiency, which in particular is beneficial for the white light. The difference occurs when a lamp is designed to emit white light and RGB light.

[0045] In the prior art LED lamp that emits combined white light and RGB light the optical efficiency will be lower (about 90%), because for having a good color mixing of the RGB light it is necessary to add e.g. a diffusor to the outer envelope to make sure that the emission profiles of the white light and that of the RGB light are matched. As a consequence, this type of lamps has a lower efficiency, because the white light also experiences the lower optical efficiency.

[0046] In the invention, the light emission profiles of the white and RBG light already match, so the optical efficiency can remain high (99%). As a result, the white light efficiency can remain the 210 lumen / watt. This is illustrated in the Table below.

[0047] In the present invention the optical efficiency is held at 99% due to the absence of a diffusor in the envelope and this raises the efficiency in lumen per watt (LPW) with about 10% with respect to the prior art LED lamp that has to fulfill the demand that the color mixing is done at the envelope.

[0048] Fig. lb illustrates the same embodiment of the present invention as Fig la. However, the LED filament lamp 100 is turned 30°, showing that the LED filament lamp 100 is rotationally symmetric.

[0049] Fig. 2a shows another schematical embodiment of the present invention. In this particular embodiment, the white LED filaments 201 are divided in two segments. Thereby, the white LED filaments 201 each comprise a first segment 207 and a second segment 208. The first segment 207 is connected to the carrier 206 and is tilted with a segment angle y from the central axis X of the LED filament lamp 200. The second segment 208 is connected to the first segment 207 and tilted with an angle P from the first segment 207 and has a second filament angle a with respect to the central axis X. The first segment 207 has a length LI and the second segment 208 has a length L2. According to the embodiment shown in Fig. 2a, L2<L1. However, in another embodiment it may be so that LI = L2, or L2>L1.

[0050] Fig. 2b shows the same embodiment of the present invention as Fig. 2a. However, the LED filament lamp is turned 30°, illustrating that the LED filament lamp 200 is rotationally symmetric.

[0051] Fig 2c shows the first and second segments 207, 208 of the white LED filament arrangement 201. The first segment angle y, the second segment angle a and the angle are also shown in Fig. 2c. The three angles form a triangle, which means that the angles can be deduced from the formula y + P + a = 180°. In another embodiment where the white LED filaments are not segmented, i.e. are linear, the angle y is referred to as filament angle.

[0052] Fig. 3a illustrates another embodiment of the LED filament lamp 300. Herein, both the white LED filament arrangement 301 and the RGB LED arrangement 302 are connected to the second end portion 313 of the carrier 306, and thus both arrangements 301, 302 are being held up by the carrier 306, while the first end portion 312 of the carrier is connected to a connector 305. In this particular embodiment, the white LED filaments 310 are divided into two segments. Thereby, the white LED filaments 310 each comprise a first segment 307 and a second segment 308. The first segment 307 is connected to the carrier 306 and is tilted with an filament angle y from the central axis X of the LED filament lamp 300. The second segment 308 is connected to the first segment 307 and tilted with an angle P from the first segment 307 and has a second filament angle a with respect to the central axis X. The RGB LED arrangement 302 comprises a first set of RGB LEDs 311 and a second set of RGB LEDs 31 L . Each RGB LED in the first set of RGB LEDs 311 are arranged between the first segments 307 of the white LED filaments 310, and each RGB LED in the second set of the RGB LEDs 311 ' are arranged between the second segments 308 of the white LED filaments 310. Thereby, the white LED filament arrangement 301 and the RGB LED arrangement 302 form a light source with a diamond structure. However, the light source can have other shapes, such as the geometrical shapes shown in Figs. 3d-3f.

[0053] Fig. 3b shows the same embodiment of the present invention as Fig. 3a. However, the LED filament lamp is turned 30°, illustrating that the LED filament lamp 300 is rotationally symmetric.

[0054] Fig. 3c illustrates a perspective view of the LED filament lamp depicted in Fig. 3a and 3c.

[0055] Figs. 3d is a top view of the light source comprising a white LED filament arrangement 301 and a RGB LED filament arrangement 302. Four RGB LEDs 311 are each placed on a PCB 303. Each PCB 303 is further arranged between two white LED filaments 310, thereby forming a square. If rotating the light source 90° it is shown that the light source is rotationally symmetric.

[0056] Fig. 3e is a top view of the light source comprising a white LED filament arrangement 301 and a RGB LED filament arrangement 302. Six RGB LEDs 311 are each placed on a PCB 303 which is arranged between two white LED filaments 310, thereby forming a hexagon. If rotating the light source 60°, it is shown that the light source is rotational symmetric.

[0057] Fig 3f is a top view of the light source comprising a white LED filament arrangement 301 and a RGB LED filament arrangement 302. Eight RGB LEDs 311 are each placed on a PCB 303 which is arranged between two white LED filaments 310, thereby forming an octagon. If rotating the light source 45°, it is shown that the light source is rotational symmetric.

[0058] Fig. 4a shows a side view of the LED filament lamp 400. In this particular embodiment, the RGB LED arrangement 402 is encircled by the white LED filament arrangement 401. In such an embodiment, the RGB LEDs 411 are arranged between the central axis X and the white LED filaments 410, while the white LED filaments 410 are arranged between the RGB LED arrangement 402 and the transparent envelope 404. Both the white LED filament arrangement 401 and the RGB LED arrangement 402 are connected to the second end portion 413 of the carrier 406, and thus both arrangements are being held up by the carrier 406. Similarly to previous embodiment in Fig. 3a and 3b of the present invention, the RGB LED arrangement 302 has a diamond shape. The first end portion 412 of the carrier 406 is connected to a connector 405.

[0059] Although the present invention has been described with reference to various embodiments, those skilled in the art will recognize that changes may be made without departing from the scope of the invention. It is intended that the detailed description be regarded as illustrative and that the appended claims including all the equivalents are intended to define the scope of the invention.

Claims

CLAIMS1. A light emitting diode (LED) filament lamp (100) having a longitudinal extension along a central axis X, the LED filament lamp (100) comprising: a white LED filament arrangement (101) comprising at least one white LED filament (110), configured to, in operation, emit white light having a white light emission profile having a first emission angle relative the central axis; an RGB LED arrangement (102) comprising at least one RGB LED (111) and, a printed circuit board, PCB, (103) for carrying the at least one RGB LED (111), wherein the PCB is arranged at a second angle in relation to the central axis, the RGB LED arrangement configured to, in operation, emit colored light having a RGB light emission profile having a second emission angle relative the central axis, wherein the second angle is equal to the second emission angle; a transparent envelope (104) at least partly enclosing the white LED filament arrangement (101) and the RGB LED arrangement (102), and a connector (105) for electrically and mechanically connecting the LED filament lamp (100) to a socket of a luminaire, wherein the white light emission profile and the RGB light emission profile are combined in ajoint emission profile, wherein the transparent envelope (104) enables color mixing at a certain distance from the at least one white LED filament (110) and the at least one RGB LED (111).

2. The LED filament lamp (100) according to claim 1, wherein the RGB LED arrangement (102) comprises an optical element arranged on top of the at least one RGB LED (111), such that the colored light emitted through the optical element has the RGB light emission profile having the second emission angle in relation to the central axis.

3. The LED filament lamp (100) according to any of the preceding claims, wherein the at least one white LED filament (110) is linear, and wherein the at least one white LED filament (110) is arranged at a filament angle in relation to the central axis.

4. The LED filament lamp (200) according to claim 1 or 2, wherein the at least one white LED filament (210) comprises a first segment (207) and a second segment (208), wherein the first segment (207) and the second segment (208) are arranged in a non-linear configuration.

5. The LED filament lamp (200) according to claim 4, wherein the first segment (207) of the at least one white LED filament (210) is arranged at a first segment angle (y) relative the central axis, and wherein the second segment (208) of the at least one white LED filament (201) is arranged at a second segment angle (a) relative the central axis.

6. The LED filament lamp (300) according to claim 4 or 5, wherein the white LED filament arrangement (301) comprises a plurality of white LED filaments (310), wherein the RGB LED arrangement (302) comprises a plurality ofRGB LEDs (311), and wherein each RGB LED (311) is configured to be arranged between two white LED filaments (310).

7. The LED filament lamp (300) according to claim 6, wherein the RGB LED arrangement (302) comprises a first set of RGB LEDs (311) and a second set of RGB LEDs (311 '), wherein each RGB LED in the first set ofRGB LEDs (311) is arranged between the first segments (307) of the white LED filaments (310), and wherein each RGB LED in the second set of the RGB LEDs (311 ) is arranged between the second segments (308) of the white LED filaments (310).

8. The LED filament lamp (400) according to any one of the preceding claims, wherein the RGB LED arrangement (402) is encircled by the white LED filament arrangement (401).

9. The LED filament lamp (100) according to any one of the preceding claims, wherein the transparent envelope (104) is closed and contains vacuum or is filled with helium (He) gas.

10. The LED filament lamp (100) according to any one of the preceding claims, the LED filament lamp further comprising a carrier (106) having a first end portion (112) anda second end portion (113) and extending along the central axis of the LED filament lamp (100).

11. The LED filament lamp (100) according to claim 10, wherein the first end portion (112) of the carrier (106) is connected to the connector (105), and the second end portion (113) of the carrier (106) is connected to the white LED filament arrangement (101).

12. The LED filament lamp (300) according to claim 10, wherein the first end portion (312) of the carrier (306) is connected to the connector (305), and the second end portion (313) of the carrier (306) is connected to the white LED filament arrangement (301) and the RGB LED arrangement (302).

13. The LED filament lamp (100) according to any of the preceding claims, wherein the at least one white LED filament (101) of the white LED filament arrangement (110) is configured, in operation, to emit light having a color temperature in the range of 2700 K - 5000 K.

14. The LED filament lamp (100) according to any one of the preceding claims, wherein the LED filament lamp (100) further comprises a controller configured, in operation, to control the white LED filament light and / or the RGB light.

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