LED filament lamp

Abstract

An LED filament lamp 1 that provides LED filament lamp light during operation is an LED filament 21-24 that emits LED filament light during operation, the LED filaments 21-24 including a plurality of LEDs 3-6 that emit LED light during operation and are arranged on elongated supports 7-10, and elongated encapsulants 11-14 that cover the plurality of LEDs 3-6 and at least a portion of the elongated supports 7-10, the elongated encapsulants 11-14 including a first luminescent material 38 that is configured to convert at least a portion of the LED light into converted light, and / or a light-scattering material 39 that is configured to scatter at least a portion of the LED light into scattered light; and a socket 51 of a lighting fixture 50 that electrically and mechanically connects the LED filament lamp 1 to the socket 51. and a translucent envelope 15 at least partially surrounding the LED filaments 21-24 and attached to the base 17, the translucent envelope 15 including a second luminescent material 37, the second luminescent material 37 including one or more of an organic phosphor 41 and quantum dots 42 dispersed in a polymer matrix 40, the second luminescent material 37 configured to convert a portion of the LED filament light to converted LED filament light, the second luminescent material 37 having absorption in a visible wavelength range, at least 80% of the visible wavelength range being within the blue and green wavelength ranges, such that the translucent envelope 15 is perceived as having an amber color.

Description

[Technical Field]

[0001] The present invention relates to an LED filament lamp that provides LED filament lamp light during operation, the LED filament emitting LED filament light during operation, the LED filament including a plurality of LEDs that emit LED light during operation and are arranged on an elongated carrier, and an elongated encapsulant that covers the plurality of LEDs and at least a portion of the elongated carrier.

[0002] It should be noted that, as used herein, the terms "blue" and "blue wavelength range" particularly relate to light having wavelengths in the range of approximately 430 to 495 nm (including some purple and cyan hues). The terms "green" and "green wavelength range" particularly relate to light having wavelengths in the range of approximately 495 to 560 nm. The terms "yellow" and "yellow wavelength range" particularly relate to light having wavelengths in the range of approximately 560 to 590 nm. The terms "orange" and "orange wavelength range" particularly relate to light having wavelengths in the range of approximately 590 to 620 nm. The terms "red" and "red wavelength range" particularly relate to light having wavelengths in the range of approximately 620 to 780 nm. The term "amber" may refer to one or more wavelengths selected from the range of approximately 580 to 605 nm, such as approximately 590 to 600 nm. The term "visible wavelength range" is intended to refer to the wavelength range of 400 to 800 nm. [Background technology]

[0003] A trend in lighting is the LED filament lamp, an LED lamp designed to resemble a traditional incandescent light bulb with a visible filament for aesthetic and light distribution purposes, but with a highly efficient light emitting diode.

[0004] The LED filament provides LED filament light and comprises a plurality of light emitting diodes (LEDs) arranged in a linear array. Preferably, the LED filament has a length L and a width W, where L>5W. The LED filament may be arranged in a straight configuration or in a non-linear configuration, for example, a curved configuration, a 2D / 3D spiral, or a helix. Preferably, the LEDs are arranged on an elongated support, for example, a support that may be rigid (for example, made from a polymer, glass, quartz, metal, or sapphire) or flexible (for example, made from a film or foil of a polymer or metal).

[0005] If the support has a first major surface and an opposite second major surface, the LED is disposed on at least one of these surfaces. The support may be reflective or light-transmitting, such as translucent, preferably transparent.

[0006] As used herein, the terms support and elongated support may be used interchangeably, such that an elongated support may sometimes be referred to simply as a support.

[0007] The LED filament may include an encapsulant at least partially covering at least some of the LEDs. The encapsulant may also at least partially cover at least one of the first major surface and the second major surface. The encapsulant may be a polymer material, such as silicone, which may be flexible. Furthermore, the LEDs may be configured to emit LED light, for example, of different colors or spectrums. The encapsulant may include a luminescent material configured to convert at least some of the LED light into converted light. The luminescent material may be a phosphor, such as an inorganic phosphor, and / or quantum dots or rods (further referred to as QDs).

[0008] An LED filament may have multiple sub-filaments.

[0009] WO 2020 / 161070 A1 discloses an LED filament lamp having an LED filament configured to emit LED filament light and an envelope including a light-absorbing material configured to absorb light in a wavelength range of 400 to 440 nm to provide an amber appearance. The envelope at least partially surrounds the LED filament of the LED filament lamp. The light-absorbing material is transparent to substantially all visible LED filament light having a wavelength longer than 440 nm. The LED filament may further include a luminescent material provided within an encapsulant surrounding the LED strip.

[0010] Many of these LED filament lamps have an amber coating on their envelope to provide a vintage or nostalgic look, however the amber coating absorbs the LED filament light.

[0011] Therefore, it is desirable to improve the performance and / or appearance of LED filaments in LED filament lamps, especially in LED filament lamps configured to have a vintage or nostalgic look.

[0012] US 2022 / 078892 discloses an LED bulb having a lamp housing and a bulb base connected to the lamp housing, wherein the spectral distribution of the bulb is generally in the wavelength range of about 400 nm to 800 nm, and three peak wavelengths P1, P2, and P3 appear within the wavelength ranges corresponding to the light emitted by the bulb, with the wavelength of peak P1 being between 430 nm and 480 nm, the wavelength of peak P2 being between 480 nm and 530 nm, and the wavelength of peak P3 being between 630 nm and 680 nm. Summary of the Invention [Problem to be solved by the invention]

[0013] The object of the present invention is to solve this problem and to provide an LED filament lamp with an LED filament of improved performance and / or appearance within such LED filament lamp, in particular within such LED filament lamp that is configured to have a vintage or nostalgic look. [Means for solving the problem]

[0014] According to a first aspect of the present invention, this and other objects are an LED filament lamp for providing LED filament lamp light during operation, the LED filament emitting LED filament light during operation, the LED filament comprising: a plurality of LEDs emitting LED light during operation and arranged on an elongated support; and an elongated encapsulant covering said plurality of LEDs and at least a portion of said elongated support, said elongated encapsulant comprising at least one of a first luminescent material configured to convert at least a portion of said LED light into converted light and a light-scattering material configured to scatter at least a portion of said LED light into scattered light, said LED filament light comprising said converted light and / or said scattered light; and an LED filament lamp for electrically and mechanically connecting said LED filament lamp to a socket of a lighting fixture. and a translucent envelope at least partially surrounding the LED filament and attached to the base, wherein the translucent envelope includes a second luminescent material, the second luminescent material including one or more of an organic phosphor and quantum dots dispersed in a polymer matrix, the second luminescent material configured to convert a portion of the LED filament light into converted LED filament light, and the second luminescent material is absorbent in the visible wavelength range, at least 80% of which is within the blue and green wavelength range, such that the translucent envelope is perceived as having an amber color.

[0015] Thereby, in particular, by providing the translucent envelope with the second luminescent material as described above, an LED filament lamp is provided in which light loss in the translucent envelope is reduced, and further the performance and / or appearance of the LED filament in such an LED filament lamp is improved. Note that the word "translucent" also includes transparency. Such an LED filament lamp further has a vintage or nostalgic look that works particularly well.

[0016] In an embodiment, the second luminescent material may be absorbing in the visible wavelength range, at least 85%, preferably at least 90%, more preferably at least 93%, and most preferably at least 95% of the visible wavelength range being within the blue and green wavelength range, such that the translucent envelope is perceived to have an amber color.

[0017] The absorptivity of the second luminescent material in the visible wavelength range may be higher in the blue wavelength range than in the green wavelength range.

[0018] It should be noted that this embodiment applies when the second luminescent material is or includes quantum dots dispersed in a polymer matrix, thereby providing an LED filament lamp with improved appearance in the off state when the LED filament does not emit LED filament light.

[0019] The second luminescent material may be absorbing in the visible wavelength range, wherein at least 55%, preferably at least 58%, more preferably at least 60% of the visible wavelength range is in the green wavelength range and at least 25%, preferably at least 28%, more preferably at least 30% is in the blue wavelength range.

[0020] It should be noted that this embodiment is applicable when the second luminescent material is or includes an organic phosphor dispersed in a polymer matrix, thereby providing an LED filament lamp with an improved appearance in the off state when the LED filament does not emit LED filament light.

[0021] The second luminescent material may be configured to convert between 3% and 30%, preferably between 3 and 15%, of the LED filament light.

[0022] Thereby, a small amount of LED filament light is converted, which provides an LED filament lamp with improved lifespan, i.e., longer lifespan, and improved visibility of the LED filament.

[0023] The LED filament light may be a white light having a first correlated color temperature (CCT1), where CCT1≦2500K.

[0024] The use of such a very low CCT LED filament light ensures that a small amount of the LED filament light is converted by the second luminescent material, which ensures that the CCT of the resulting LED filament lamp light is also kept within a CCT range that is sufficiently low to be acceptable to the human eye and therefore suitable for providing an LED filament lamp light that resembles the lamp light of a traditional vintage lamp, particularly an incandescent bulb.

[0025] The LED filament light may be white light having a first correlated color temperature (CCT1), and the LED filament lamp light is white light having a second correlated color temperature (CCT2), where CCT2-CCT1≦500K.

[0026] This ensures that the CCT of the resulting LED filament lamp light is only slightly shifted toward a cooler CCT, thereby keeping the CCT of the LED filament lamp light within a CCT range of sufficiently low values ​​that is favorable to perception by the human eye and therefore suitable for providing LED filament lamp light that resembles the lamp light of conventional vintage lamps, particularly incandescent bulbs.

[0027] The polymer matrix may contain non-luminescent nanoparticles, especially those with diameters smaller than the visible wavelength range.

[0028] By providing such non-luminescent nanoparticles, the converted LED filament light can be scattered outside the envelope while ensuring that the envelope remains translucent, thereby ensuring high visibility of the LED filament.

[0029] The second luminescent material may include one or more of a first phosphor configured to emit a first phosphor light having a dominant wavelength (DW1) in a wavelength range of 550 to 580 nm, and a second phosphor configured to emit a second phosphor light having a dominant wavelength (DW2) in a wavelength range of 500 to 550 nm. In an example, the dominant wavelength (DW) of the converted light emitted by a phosphor may be defined, in terms of a correlated color diagram, as the wavelength at which (i) the color coordinates of the converted light and (ii) the line (L) passing through points x=0.333 and y=0.333 intersect the spectral locus (i.e., the boundary of the correlated color diagram).

[0030] This can be achieved if the second luminescent material is or comprises an organic phosphor dispersed in the polymer matrix, and the second luminescent material can be absorbing in the visible wavelength range, where at least 55%, preferably at least 58%, more preferably at least 60% of the visible wavelength range is in the green wavelength range and at least 25%, preferably at least 28%, more preferably at least 30% is in the blue wavelength range. The second luminescent material is configured to convert 3% to 30%, or 3% to 15% of the LED filament light. The second luminescent material may comprise a first (organic / QD) phosphor, such as a first (organic / QD) phosphor comprising Lumogen F-240, a second (organic / QD) phosphor, such as a second (organic / QD) phosphor comprising Lumogen F-083, or both a first (organic / QD) phosphor and a second (organic / QD) phosphor comprising Lumogen F-240 and Lumogen F-083. The second luminescent material 37 may further be configured to provide no, substantially no, or little scattering of the LED filament light.

[0031] Such phosphors have proven particularly effective in providing the desired amber appearance of the LED filament lamps.

[0032] The LED filament may be free of organic phosphors and quantum dots, and the translucent envelope may be free of inorganic phosphors.

[0033] This provides an LED filament lamp in which the envelope is still perceived as amber while the LED filament has improved performance and / or appearance within the LED filament lamp, and such LED filament lamp also has a vintage or nostalgic look that also performs better.

[0034] The LED filament has an off state in which the LED filament does not emit LED filament light and an on state in which the LED filament emits LED filament light, and the LED filament is visible through the translucent envelope in both the off state and the on state.

[0035] Thereby, an LED filament lamp is provided that includes high visibility of the LED filament and improved appearance in both the off state and the on state.

[0036] The first luminescent material may comprise one or more of a green-yellow inorganic phosphor configured to emit green-yellow light and a red inorganic phosphor configured to emit red light, and the inorganic phosphor may be an organic phosphor or a phosphor that does not include QDs.

[0037] Such phosphors have proven to be particularly efficient and work well to provide the LED filament light with desired parameters, particularly the desired CCT and wavelength spectrum.

[0038] The green to yellow inorganic phosphor may include one or more of a YAG phosphor and a LuAG phosphor, and the red inorganic phosphor may include a KSiF phosphor.

[0039] The elongated support may be light-transmitting and may have a further encapsulant provided on a second side of the support opposite to a first side of the support on which the plurality of LEDs are arranged, the further encapsulant including at least one of a further luminescent material configured to convert at least a portion of the LED light and / or converted light into further converted light, and a further light-scattering material configured to scatter at least a portion of the LED light and / or converted light into further scattered light.

[0040] This prevents the support from absorbing the LED filament light, thereby providing an LED lamp with improved light intensity from the LED filament lamp.

[0041] The translucent envelope may comprise a glass envelope and the second luminescent material may be provided as a coating on the glass envelope.

[0042] Thereby an LED filament lamp is provided that is particularly simple to manufacture.

[0043] The translucent envelope may have a neck, the neck forming the portion of the translucent envelope that is attached to the base, and the neck may be free of the second luminescent material.

[0044] This provides an LED filament lamp with an appearance that visually more closely resembles a vintage lamp, especially in the off state.

[0045] The second luminescent material may further be configured to provide no or substantially no scattering.

[0046] This ensures that the LED filament is still clearly visible through the second luminescent material.

[0047] The LED filament lamp may have multiple LED filaments.

[0048] The LED filaments may be identical, or alternatively, the LED filaments may differ from one another, for example, in terms of color, length and / or light conversion properties.

[0049] Thereby, the LED lamp can have LED filament structures with a wide variety of appearances.

[0050] The invention further relates to a lighting fixture comprising at least one LED filament lamp according to the invention.

[0051] It is to be noted that the invention relates to all possible combinations of the features recited in the claims. [Brief explanation of the drawings]

[0052] This and other aspects of the invention will now be described in more detail with reference to the accompanying drawings, in which embodiments of the invention are shown. [Figure 1] 1 shows a perspective view of a first luminescent material and an LED filament lamp according to the present invention comprising the first luminescent material; [Figure 2] 2 shows a more detailed perspective view of an exemplary LED filament of the LED filament lamp according to FIG. 1; [Figure 3] 1 shows a schematic close-up view of an exemplary second luminescent material. [Figure 4] 1 shows graphs illustrating the absorption coefficients (dashed lines) and emission spectra (solid lines) of a number of different suitable phosphors plotted as normalized intensity as a function of wavelength of incident light, respectively. [Figure 5] 1 shows a graph illustrating the spectrum of light produced from an LED filament according to the present invention as perceived by an observer as a function of wavelength. [Figure 6] 1 shows a vertical cross-sectional view of a lighting fixture with an LED filament lamp according to the present invention.

[0053] The sizes of layers and regions as shown in the figures have been exaggerated for illustrative purposes and are therefore shown to illustrate the general structure of embodiments of the present invention. Like reference numerals refer to like elements throughout. DETAILED DESCRIPTION OF THE INVENTION

[0054] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which presently 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 presented for thoroughness and completeness, and will fully convey the scope of the invention to those skilled in the art.

[0055] Referring to FIG. 1 , an exemplary LED filament lamp 1 according to the present invention is shown. The LED filament lamp 1 is configured to emit LED filament lamp light L3 during operation. The LED filament lamp 1 is shown in the form of a light bulb. The LED filament lamp 1 includes an LED filament array 2. In the illustrated embodiment, the LED filament array 2 includes substantially straight filaments 21-24. In other embodiments, the filaments 21-24 of such an LED filament array 2 may have other shapes, such as, but not limited to, spiral, helical, serpentine, twisted, flat, and combinations thereof. In the illustrated embodiment, the LED filament lamp 1 includes four LED filaments 21, 22, 23, and 24. In other embodiments, the LED filament lamp 1 may include other numbers of LED filaments, such as one, two, three, or five LED filaments, whether less than or more than four. Each LED filament 21-24 is configured to emit LED filament light L2 during operation.

[0056] 2, the LED filaments 21-24 each include a plurality of LEDs 3, 4, 5, and 6. The plurality of LEDs 3-6 is configured to emit LED light L1 during operation. Each of the plurality of LEDs 3-6 is disposed on a respective elongated support 7, 8, 9, 10, in particular on a first surface 71 of the elongated support 7-10.

[0057] Elongated encapsulants 11, 12, 13, and 14 are provided. As can be seen more clearly in FIG. 2 , each elongated encapsulant 11-14 covers a respective one of the plurality of LEDs 3-6 and at least a portion of the associated elongated support 7-10. Each elongated encapsulant 11-14 is therefore disposed on a surface of the respective elongated support 7-10 on which the respective one of the plurality of LEDs 3-6 is disposed, specifically the first surface 71. Each elongated encapsulant 11-14 includes one or both of a first luminescent material 38 configured to at least partially convert LED light L1 into converted LED light and a light-scattering material 39 configured to at least partially scatter the LED light into scattered LED light. The first luminescent material 38 may include a yellow inorganic phosphor, a red inorganic phosphor such as a KSiF phosphor, or a combination of a yellow inorganic phosphor and a red inorganic phosphor such as YAG and KSiF. The inorganic phosphor may be an organic phosphor or a phosphor that does not include QDs.

[0058] Therefore, the LED filament light L2 includes not only the LED light L1 but also the converted LED light and / or the scattered LED light. Generally, the LED filament light L2 has a first correlated color temperature CCT1, and the first correlated color temperature CCT1 is 2500K or less.

[0059] The elongated supports 7-10 have electrical wiring 25 and 26 (see FIG. 2) for supplying electrical energy to the plurality of LEDs 3-6 mounted on the elongated supports 7-10. The elongated supports 7-10 may be substrates or printed circuit boards (PCBs).

[0060] The elongated supports 7-10 may also be optically transparent. In such cases, an encapsulant 43 may be provided on a second surface 72 of the supports 7-10 opposite a first surface 71 of the supports 7-10 on which the LEDs 3-6 are disposed. Optionally, the encapsulant 43 may also include one or more of a luminescent material similar to or identical to the first luminescent material 38 described above and a light-scattering material similar to or identical to the light-scattering material 39 described above. In other examples, the encapsulant 43 may include at least one of a further luminescent material configured to convert at least a portion of the LED light and / or the converted light into further converted light and a further light-scattering material configured to scatter at least a portion of the LED light and / or the converted light into further scattered light.

[0061] Referring again to FIG. 1 , the LED filament lamp 1 further includes a translucent envelope 15 at least partially surrounding the at least one LED filament array 2. The translucent envelope 15 may be shaped into any possible shape, such as resembling a standard light bulb, a spherical light bulb, a candle light bulb, a customized light bulb, or even a spiral light bulb. The translucent envelope 15 includes a second luminescent material 37. Referring also to FIG. 3 , the second luminescent material 37 includes one or more of a phosphor 41 dispersed in a polymer matrix 40 and quantum dots 42 dispersed in the polymer matrix 40. The polymer matrix 40 may further include non-luminescent nanoparticles. The non-luminescent nanoparticles may have a diameter shorter than the visible wavelength range. The second luminescent material 37 is configured to partially convert the LED filament light L2 into converted LED filament light. Thus, the LED filament lamp light L3 includes the LED filament light L2 and the converted LED filament light. The second luminescent material 37 has an absorption such that at least 80% of its absorption in the visible wavelength range is in the blue and green wavelength range, thereby imparting an amber color to the translucent envelope 15 as perceived by an observer. The second luminescent material may be provided as a coating on the translucent envelope 15. Alternatively, or in addition, the second luminescent material may be provided within the bulk of the translucent envelope 15. The second luminescent material 37 may also have a thickness or concentration gradient across the translucent envelope 15.

[0062] When the second luminescent material 37 is or comprises quantum dots 42 dispersed in a polymer matrix 40, the absorption of the second luminescent material 37 in the visible wavelength range is higher in the blue wavelength range than in the green wavelength range. When the second luminescent material 37 is or comprises an organic phosphor 41 dispersed in a polymer matrix 40, the second luminescent material 37 may have absorption in the visible wavelength range, where at least 55%, preferably at least 58%, more preferably at least 60% of the visible wavelength range is in the green wavelength range and at least 25%, preferably at least 28%, more preferably at least 30% is in the blue wavelength range. The second luminescent material 37 is configured to convert 3% to 30%, or 3% to 15% of the LED filament light. The second luminescent material 37 may comprise a first (organic / QD) phosphor, such as a first (organic / QD) phosphor comprising Lumogen F-240, a second (organic / QD) phosphor, such as a second (organic / QD) phosphor comprising Lumogen F-083, or both a first (organic / QD) phosphor and a second (organic / QD) phosphor comprising Lumogen F-240 and Lumogen F-083. The second luminescent material 37 may also be configured to provide no, substantially no, or little scattering of the LED filament light.

[0063] The translucent envelope 15 may be a glass envelope. In such a case, the second luminescent material 37 may be provided as a coating on the glass envelope. The translucent envelope 15 may further include a neck 16. The neck 16 may include the second luminescent material 37. In other examples, the neck 16 may not include the second luminescent material 37.

[0064] The LED filament lamp 1 further has a base 17, such as a cap, to which the translucent envelope 15 is connected or attached. The base 17 is configured to electrically and mechanically connect the LED filament lamp 1 to a socket of a lighting fixture (see FIG. 6). If provided, the neck 16 forms the portion of the translucent envelope 15 that is connected or attached to the base 17.

[0065] The LED filament lamp 1 may further have threads 18 for connection to a socket and terminals 19 for connection to a source of electrical energy. The threads 18 and terminals 19 may form part of the base 17 or may be provided on the base 17.

[0066] The LED filament lamp 1 may optionally further include a driver or controller 30 configured to control the LED filament lamp 1. The driver or controller 30 may be an external unit, a unit disposed within the LED filament lamp 1 as shown in FIG. 1, or a combination of both such units. The controller 30 is configured to power the plurality of LEDs 3-6 via an electrical circuit (not shown) of the LED filament lamp 1. The controller 30 may further be configured to control at least one of the CCT of the LED filament lamp light L3 and the CRI of the LED filament lamp light L3. The controller 30 may also be configured to control other parameters related to the LED filament lamp light source (i.e., the plurality of LEDs 3-6) and the LED filament lamp light L3. As shown in FIG. 1, the controller 30 is disposed within the translucent envelope 15. The controller 30 may also be disposed within the base 17 so as to be hidden from view.

[0067] The LED filament lamp 1 may further include an exhaust pipe 31. The exhaust pipe 31 is disposed within a stem 33 of the LED filament lamp 1, preferably in the center. The exhaust pipe 31 is configured to seal gas between the translucent envelope 15 and the exhaust pipe 31. The controller 30 may be disposed between the translucent envelope 15 and the exhaust pipe 31.

[0068] The LED filament lamp 1 may further include one or two conductive base wires 32. The one or two conductive base wires 32 are separate from the at least two conductive wires 25 and 26. In the embodiment shown in FIG. 1, the connection between the one or two conductive base wires 32 and the conductive wires 25 and 26 of each LED filament 21-24 is achieved by a respective wire segment 34 connected at a first end to the one or two conductive base wires 32. At a second end opposite the first end (not visible in the figure), the one or two conductive base wires 32 pass through the exhaust pipe 31 so as to be electrically connected to a driver 52 (see FIG. 6), a controller 30, or a power source.

[0069] Figure 4 illustrates the absorption coefficient and emission spectrum of each of a number of different suitable phosphors plotted as normalized intensity as a function of wavelength of incident light. The absorption coefficient is shown as a dashed line and the emission spectrum is shown as a solid line. The incident light is LED light with a correlated color temperature (CCT) of 2200K.

[0070] Graphs C and D show the absorption coefficient and emission spectrum, respectively, of Lumogen F-083 phosphor (i.e., the second phosphor), and graphs E and D show the absorption coefficient and emission spectrum, respectively, of Lumogen F-240 phosphor (i.e., the first phosphor).

[0071] 5 shows a graph illustrating the spectrum of light as a function of wavelength resulting from an exemplary LED filament lamp according to the present invention including second luminescent material 37 as perceived by an observer. It can be seen that the spectrum of light, or at least the dominant wavelength of light in said spectrum, corresponds to that of light perceived by an observer as having an amber color.

[0072] Turning finally to Fig. 6, an exemplary lighting fixture in the form of a pendant 50 is shown. The pendant 50 includes an LED filament lamp 1 according to any embodiment of the present invention. In the embodiment shown, the LED filament lamp 1 is of the type shown in Fig. 1 and has a substantially straight filament. The filament of such an LED filament lamp 1 may, in other embodiments, have a filament with another shape, such as, but not limited to, a spiral, a helix, a serpentine, a twisted, a flat, and combinations thereof.

[0073] The pendant 50 further has a socket 51 for connecting the LED filament lamp 1 to the pendant 50. The socket 51 is adapted to cooperate with the base 17 of the LED filament lamp 1. The socket 51 may have threads adapted to cooperate with threads 18 of the LED filament lamp 1. The socket 51 may have terminals adapted to cooperate with terminals 19 of the LED filament lamp 1.

[0074] The pendant 50 may further include a driver 52 configured to control the LED filament lamp 1. The driver 52 may be the same unit as the controller 30 described above, or may not be the same unit as the controller 6 described above. In other words, the driver 52 and the controller 30 may be integrated into the same driver or controller, or may be separate units. The driver 52 is configured to supply power to the multiple LED filaments 21 to 24 via the conductive wires of the LED filament lamp 1. The driver 52 may further be configured to control at least one of the CCT of the LED filament lamp light L3 and the CRI of the LED filament lamp light L3. The driver 52 may also be configured to control other parameters related to the LED filament lamp light source (i.e., the multiple LEDs 3 to 6) and the LED filament lamp light L3.

[0075] 6, the driver 52 is disposed on a reflector or screen 53 of the pendant 50. The driver may also be disposed within or integrated into the reflector or screen 53. The pendant 50 further includes electrical wiring 54 for connection to a power source, such as a mains supply.

[0076] It should be noted that the pendant 50 shown in Figure 6 is only one example of a luminaire in accordance with the present invention. Any suitable type of luminaire may be contemplated, including, but not limited to, a standing luminaire, a wall hung luminaire, a chandelier, a reading luminaire, an outdoor luminaire, a table luminaire, etc.

[0077] Those skilled in the art will appreciate that the present invention is by no means limited to the preferred embodiments described above, but on the contrary, many modifications and variations are possible within the scope of the appended claims.

[0078] Furthermore, those skilled in the art will understand and achieve modifications to the disclosed embodiments in practicing the claimed invention, from a study of the drawings, the specification and the appended claims. In the claims, the word "comprises" does not exclude other elements or steps, and the singular 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

1. an LED filament lamp that provides LED filament lamp light during operation; an LED filament that emits LED filament light during operation, the LED filament including: a plurality of LEDs that emit LED light during operation and that are disposed on an elongated support; and an elongated encapsulant that covers the plurality of LEDs and at least a portion of the elongated support, the elongated encapsulant including at least one of a first luminescent material configured to convert at least a portion of the LED light into converted light and a light-scattering material configured to scatter at least a portion of the LED light into scattered light, the LED filament light including the converted light and / or the scattered light; a base configured to electrically and mechanically connect the LED filament lamp to a socket of a lighting fixture; a translucent envelope at least partially surrounding the LED filament and attached to the base, the translucent envelope comprises a second luminescent material, the second luminescent material comprising one or more of an organic phosphor and quantum dots dispersed in a polymer matrix, the second luminescent material configured to convert a portion of the LED filament light into converted LED filament light, the second luminescent material having absorption in a visible wavelength range, at least 80% of the visible wavelength range being within blue and green wavelength ranges, such that the translucent envelope is perceived to have an amber color; the second luminescent material is a first phosphor configured to emit first phosphor light having a dominant wavelength within a wavelength range of 550 to 580 nm; and An LED filament lamp including one or more second phosphors configured to emit second phosphor light having a dominant wavelength within a wavelength range of 500 to 550 nm.

2. 2. An LED filament lamp as claimed in claim 1, wherein the absorption of said second luminescent material in said visible wavelength range is higher in the blue wavelength range than in the green wavelength range.

3. 2. An LED filament lamp as claimed in claim 1, wherein said second luminescent material has absorption in said visible wavelength range, wherein at least 55% of said visible wavelength range is in the green wavelength range and at least 25% is in the blue wavelength range.

4. 4. An LED filament lamp according to any one of claims 1 to 3, wherein the second luminescent material is configured to convert between 3% and 30%, preferably between 3% and 15%, of the LED filament light.

5. 5. An LED filament lamp according to claim 1, wherein the LED filament light is white light having a first correlated color temperature CCT1, and CCT1≦2500K.

6. The LED filament light is white light having a first correlated color temperature CCT1, and the LED filament lamp light is white light having a second correlated color temperature CCT2, and CCT2-CCT1≦500K. An LED filament lamp according to any one of claims 1 to 5.

7. 7. An LED filament lamp according to claim 1, wherein the LED filament does not contain organic phosphors and quantum dots, and the translucent envelope does not contain inorganic phosphors.

8. 8. An LED filament lamp according to any one of claims 1 to 7, wherein the LED filament is visible through the translucent envelope in an off state in which the LED filament does not emit LED filament light and in an on state in which the LED filament emits LED filament light.

9. 9. An LED filament lamp according to any one of claims 1 to 8, wherein the first luminescent material comprises a green to yellow inorganic phosphor configured to emit green to yellow light, and a red inorganic phosphor configured to emit red light.

10. 10. The LED filament lamp according to claim 9, wherein the green to yellow inorganic phosphor comprises a YAG and / or LuAG phosphor, and the red inorganic phosphor comprises a KSiF phosphor.

11. 11. An LED filament lamp as claimed in any one of claims 1 to 10, wherein the elongated support is light-transmitting, and a further encapsulant is provided on a second surface of the support opposite to a first surface of the support on which the plurality of LEDs are arranged, the further encapsulant including at least one of a further luminescent material configured to convert at least a portion of the LED light and / or converted light into further converted light, and a further light-scattering material configured to scatter at least a portion of the LED light and / or converted light into further scattered light.

12. 12. An LED filament lamp as claimed in any one of claims 1 to 11, wherein the translucent envelope comprises a glass envelope and the second luminescent material is provided as a coating on the glass envelope.

13. 13. An LED filament lamp as claimed in any one of claims 1 to 12, wherein the translucent envelope has a neck, the neck forming the portion of the translucent envelope that is attached to the base, and the neck not including the second luminescent material.

14. A lighting fixture comprising at least one LED filament lamp according to any one of claims 1 to 13.

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