CCT-controllable LED filament device with LED filament that has the same color appearance in the light-off state

Abstract

The present disclosure describes a light-emitting diode (LED) filament device 100 for providing device light, the light-emitting diode (LED) filament device 100 including a first LED filament 110 configured to emit a first LED filament light having a first correlated color temperature CCT1, a second LED filament 160 configured to emit a second LED filament light having a second correlated color temperature CCT2, and a controller 210 for individually controlling the first LED filament light emitted by the first LED filament 110 and the second LED filament light emitted by the second LED filament 160 so that the device light is variable in correlated color temperature. The present disclosure also describes an LED filament lamp 220 including the LED filament device 100, the LED filament lamp 220 further including an envelope 230 at least partially surrounding the first LED filament 110 and the second LED filament 160, and a base 240 for electrically and mechanically connecting the LED filament lamp 220 to a socket of a lighting fixture. The present disclosure also describes a lighting fixture 250 having an LED filament device 100 or LED filament lamp 220.

Description

[Technical Field]

[0001] The present invention relates generally to an LED filament device, and more particularly to an LED filament device for providing light with an adjustable correlated color temperature. [Background technology]

[0002] The field of lighting technology is experiencing rapid development due to the introduction of new technologies such as light-emitting diodes (LEDs). This field is under constant transformation and continues to attract attention. Compared to traditional light sources such as incandescent, fluorescent, and neon lamps, apparatus or devices including LEDs offer many advantages, such as increased flexibility and control, more compact design, and / or reduced power consumption. Notably, traditional light sources are rapidly being replaced by LED-based lighting solutions.

[0003] Apparatuses or devices such as LED filament lamps or luminaires may be used to provide light with an adjustable correlated color temperature (CCT). A device with an adjustable CCT can be obtained by providing multiple LED filaments, each configured to provide light with a different CCT. A problem with the above is that the device has different LED filaments that have different colors in the off state and therefore appears visually unpleasant. Summary of the Invention [Problem to be solved by the invention]

[0004] It is therefore an object of the present invention to provide a lighting device that alleviates this drawback.

[0005] WO 2020 / 260197 relates to a lighting device having an elongated first LED filament and an elongated second LED filament. The lighting device further includes an at least partially light-transmitting envelope at least partially enclosing the first LED filament and the second LED filament, and a base to which the at least partially light-transmitting envelope is attached. The first LED filament is configured to emit light having a different color temperature than the second LED filament. Furthermore, the second LED filament is at least partially curved to define at least a portion of the contour of a volume. The first LED filament is at least partially disposed within the volume. [Means for solving the problem]

[0006] A first aspect of the present invention is a light-emitting diode (LED) filament device for providing device light, comprising: a first LED filament configured to emit first LED filament light having a first correlated color temperature CCT1; a first carrier; a plurality of first LEDs disposed on the first carrier, each first LED configured to emit first LED light having a first peak wavelength λ1; and a first encapsulant encapsulating the plurality of first LEDs and at least partially covering the first carrier, the first encapsulant including a first luminescent material configured to at least partially convert the first LED light into a first converted light, the first encapsulant having a first light-source off-state color appearance. a first LED filament having a first encapsulant having a wavelength (λ) of 1000 nm; a second LED filament configured to emit second LED light having a second correlated color temperature (CCT2); a second carrier; a plurality of second LEDs disposed on the second carrier, each second LED configured to emit second LED light having a second peak wavelength (λ); and a second encapsulant encapsulating the plurality of second LEDs and at least partially covering the second carrier, the second encapsulant including a second luminescent material configured to at least partially convert the second LED light into a second converted light. and a controller for individually controlling the first LED filament light emitted by the first LED filament and the second LED filament light emitted by the second LED filament so that the device light is variable in correlated color temperature, wherein λ1 is in the range of 430 to 494 nm, λ2=487+ / -7 nm, CCT1≦(CCT2-500K), and A1 and A2 are the same.

[0007] The LED filament device can be used to provide device light with an adjustable CCT, and the LED filament of the LED filament device has the same color appearance in the off state. Tests have shown that λ1 in the range of 430 to 494 nm and λ2 = 487 + / - 7 nm makes it possible to provide device light with a high CCT while simultaneously generating melanopic light. The LED filament device also makes it possible to use similar materials for the first encapsulant and the second encapsulant, thus allowing the LED filament of the LED filament device to have the same color appearance in the off state.

[0008] In an embodiment of the present invention, λ1 = 450 + / - 20 nm, λ2 = 487 + / - 7 nm, and λ2 - λ1 ≥ 20 nm. The use of these specific wavelengths allows for the use of similar phosphors and phosphor ratios, and therefore allows the LED filaments of the LED filament device to have the same color appearance in the off state. The use of these specific wavelengths results in favorable light quality because two different types of blue light can be used, creating controllable melanopic light while simultaneously providing device light with a high CCT.

[0009] In another embodiment of the invention, λ1 = 487 + / - 7 nm and λ2 = 487 + / - 7 nm. The use of these specific wavelength ranges is advantageous because it allows the first luminescent material and the second luminescent material to be similar or the same material, and therefore allows the LED filaments of the LED filament device to have the same color appearance in the off state. The use of these specific wavelength ranges also allows both the first LED filament and the second LED filament to emit white light over a wide range of correlated color temperatures and to produce melanopic light at a low CCT.

[0010] In yet another embodiment of the invention, the first encapsulant has a first thickness T1 and a first luminescent material concentration C1, and the second encapsulant has a second thickness T2 and a second luminescent material concentration C2, where T2≦0.8T1 and / or C2≦0.8C1, and the resulting effect is that CCT1 and CCT2 can be chosen to be different to provide device light with an adjustable CCT.

[0011] In yet another embodiment of the invention, the first luminescent material comprises a green and / or yellow phosphor and a red phosphor, and the second luminescent material comprises a green and / or yellow phosphor and a red phosphor, and thus the emissions by the first and second luminescent materials can be selected to at least partially determine CCT1 and CCT2.

[0012] In yet another embodiment of the present invention, the green and / or yellow phosphor of the first luminescent material is the same as the green and / or yellow phosphor of the second luminescent material, and optionally the red phosphor of the first luminescent material is the same as the red phosphor of the first luminescent material, with the resulting effect being that the first LED filament and the second LED filament obtain a light source off state color appearance.

[0013] In yet another embodiment of the invention, the green and / or yellow phosphor has an excitation intensity at the second peak wavelength λ2 that is lower than the excitation intensity at the first peak wavelength λ1. The excitation intensities of the first and second luminescent materials may be selected to at least partially determine the difference between CCT1 and CCT2 such that the CCT of the device light may be adjusted.

[0014] In yet another embodiment of the present invention, the difference between the excitation intensities at the first and second peak wavelengths is at least 20% of the peak excitation intensity of the green and / or yellow phosphor. Thus, the excitation intensities due to the first and second luminescent materials can be of a certain magnitude such that CCT1 and CCT2 can be different.

[0015] In yet another embodiment of the invention, CCT1≦2500 K and CCT2≧2700 K, preferably CCT1 being in the range of 800 to 2400 K. The difference between CCT1 and CCT2 allows for a large variation in the CCT of the device light.

[0016] In yet another embodiment of the invention, the device light is configured to be adjusted between a third correlated color temperature CCT3 and a fourth correlated color temperature CCT4, where CCT3≦2500 K, and CCT4≧2700 K, and CCT3≦CCT4−500 K. This difference between CCT3 and CCT4 has been found by the inventors to be preferable in a wide range of applications, such as LED filament lamps and luminaires.

[0017] In yet another embodiment of the present invention, CCT1≦2300 K, CCT3≦2300 K, CCT2≧3000 K, and CCT4≧3000 K. This difference between CCT3 and CCT4 has been found by the inventors to be preferable in a wide range of applications, such as LED filament lamps and luminaires.

[0018] In yet another embodiment of the present invention, any one or more of the first luminescent material and the second luminescent material is selected from the group consisting of A3B5O 12: Ce type luminescent material, A includes one or more of Y, La, Gd, Tb and Lu, and B includes one or more of Al, Ga, In and Sc, and the device light is white light with a correlated color temperature in the range of 1800 to 6500 K and a color rendering index of at least 80. This selection of the first luminescent material and the second luminescent material allows for a desirable wavelength distribution of the converted light and a high excitation probability.

[0019] In yet another embodiment of the present invention, any one or more of the first luminescent material and the second luminescent material comprises KSiF phosphor, This selection of the first luminescent material and the second luminescent material enables a desirable wavelength distribution of the converted light and a high excitation probability.

[0020] A second aspect of the present invention provides an LED filament lamp having an LED filament device, further comprising an envelope at least partially surrounding the first LED filament and the second LED filament, a base for electrically and mechanically connecting the LED filament lamp to a socket of a lighting fixture, and an antenna for wirelessly controlling the controller. The LED filament lamp can be used to provide light with an adjustable CCT, and the LED filaments of the LED filament lamp have the same color appearance in the off state.

[0021] A third aspect of the present invention provides a luminaire having an LED filament device or LED filament lamp, which can be used to provide light with an adjustable CCT, and wherein the LED filaments of the luminaire have the same color appearance in the off state. [Brief explanation of the drawings]

[0022] 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 illustrates a schematic diagram of an LED filament device having a first LED filament, a second LED filament, and a controller. [Figure 2] 10A and 10B schematically illustrate a first LED filament and a second LED filament, each of which has a carrier, a plurality of LEDs, and an encapsulant, and the thickness of the encapsulant of the first LED filament is thinner than the thickness of the encapsulant of the second LED filament. [Figure 3] 1 illustrates a schematic diagram of an LED filament lamp having an LED filament device. [Figure 4] 1 shows a schematic illustration of the relative intensities of the first LED, the second LED and the blue LED, and the excitation spectrum of a YAG:Ce type phosphor. [Figure 5] 1 schematically illustrates a CIE color space chromaticity diagram in which the correlated color temperature of a first LED filament and the correlated color temperature of a second LED filament are shown. [Figure 6] 1 illustrates a schematic representation of a lighting fixture having an LED filament device. DETAILED DESCRIPTION OF THE INVENTION

[0023] In the following, general and specific exemplary embodiments of the present invention are described. Reference is made to the accompanying drawings. It should be noted, however, that the drawings are exemplary embodiments only, and that other features and embodiments may well fall within the scope of the invention as claimed. Furthermore, the singular form "a," "an," or "the" should not be construed to exclude pluralities, and the term "disclosure" can be used interchangeably with the term "invention" herein.

[0024] Unless otherwise defined, all technical terms, notations, and other scientific or technical terms used herein are intended to have the meanings commonly understood by those of ordinary skill in the art to which the invention pertains. However, certain technical terms, notations, and other scientific or technical terms may be specifically defined as set forth below.

[0025] The present invention relates to an LED filament device, an LED filament lamp having an LED filament device, and a lighting fixture having an LED filament device.

[0026] 1, an LED filament device 100 according to the present invention includes a first LED filament 110, a second LED filament 160, and a controller 210. The first LED filament 110 and the second LED filament 160 may be connected to the controller 210, for example, via a direct or indirect electronic connection, as shown.

[0027] The first LED filament is configured to emit a first LED filament light having a first correlated color temperature CCT1, and the second LED filament is configured to emit a second LED filament light having a second correlated color temperature CCT2. The controller is configured to individually control the first LED filament light and the second LED filament light so that the LED filament device as a whole can emit device light. By controlling the intensity and correlated color temperature of the first LED filament light and the second LED filament light, the correlated color temperature (CCT) of the device light can be changed. The controller itself may be, for example, pre-programmed or may be controlled, for example, via an external switch, an external control unit, or the like. The controller may, for example, have an antenna for wirelessly communicating with an external controller unit or may be connected to said antenna.

[0028] 2 and 3, according to the present invention, a first LED filament 110 includes a first carrier 120, a plurality of first LEDs 130, and a first encapsulant 140, while a second LED filament 160 includes a second carrier 170, a plurality of second LEDs 180, and a second encapsulant 190. The plurality of first LEDs 130 and the plurality of second LEDs 180 are arranged, for example, periodically, on the first carrier 120 and the second carrier 170, respectively. The encapsulant 140, 190 of each filament 110, 160 is arranged to encapsulate the plurality of LEDs 130, 180 arranged on the carrier 120, 170 of the filament 110, 160, and to at least partially cover the carrier 120, 170. An LED 130, 180 disposed on an LED filament 110, 160 may be considered herein encapsulated by an encapsulant if any light emitted by the LED must pass through the encapsulant 140, 190 before escaping the LED filament 110, 160. An LED 130, 180 residing in a carrier 120, 170 and encapsulated by the encapsulant 140, 190 may therefore generally be in contact with the carrier 120, 170 and the encapsulant 140, 190. A first LED filament may, in certain embodiments, include only a first LED. A second LED filament may, in certain embodiments, include only a second LED.

[0029] Each carrier 120, 170 may be an elongated body, e.g., with a longitudinal length in the range of about 1 cm and a lateral width in the range of about 1 mm, as schematically illustrated in FIG. 1 or 2. A plurality of first LEDs 130 and a plurality of second LEDs 180 may be disposed on the first carrier 120 and the second carrier 170, respectively, e.g., evenly spaced along the longitudinal direction of the elongated body of the associated carrier 120, 170. For each carrier 120, 170, the plurality of LEDs 130, 180 may be connected to power via the carrier 120, 170, e.g., via one or more electrical conductors in the carrier 120, 170, or by the carrier 120, 170 itself acting as a conductor. Those skilled in the art with knowledge of this disclosure will understand that either or both of the first carrier 120 and the second carrier 170 may have various shapes, and that the arrangement of the LEDs 130, 180 on either carrier 120, 170 may vary. Either or both of the first carrier 120 and the second carrier 170 may be shaped, for example, as a spiral, a loop, or the like.

[0030] According to the present invention, the first encapsulant and the second encapsulant may include a first luminescent material and a second luminescent material, respectively. The first luminescent material is configured to at least partially convert a first LED light into a first converted light, and the second luminescent material is configured to at least partially convert a second LED light into a second converted light. Each luminescent material may absorb at least a portion of the LED light from the LED it encapsulates and re-emit the converted light in the form of luminescent radiation. The intensity and wavelength distribution of the converted light emitted by the encapsulant may depend on both the characteristics of the LED light emitted by the encapsulated LED and the characteristics of the encapsulant. The characteristics of the LED light may include one or more of the intensity and wavelength distribution. The characteristics of the encapsulant may include one or more of the thickness, transmission characteristics, and excitation intensity of the encapsulant. FIG. 4 schematically illustrates the relative intensity of the excitation spectrum of a blue LED and a YAG:Ce-type encapsulant. Here, it can be seen that the excitation spectrum is shifted relative to the wavelength distribution of the blue LED. As shown schematically in Figure 4, the first and second LED lights have peak wavelengths λ1 and λ2, where λ1 = 440 nm and λ2 = 487 nm.

[0031] The excitation intensities of the first and second encapsulants may depend, inter alia, on the first luminescent material concentration C1 and the second luminescent material concentration C2, respectively. Accordingly, C1 and C2 may be selected to at least partially determine the amount of first converted light and second converted light, respectively. According to certain embodiments of the present disclosure, the first luminescent material concentration may be greater than the second luminescent material concentration. More preferably, the first luminescent material concentration and the second luminescent material concentration may be selected such that C2≦0.8C1. This may allow for a greater amount of first converted light relative to the second converted light, shifting the first filament light to the right of the CIE color space chromaticity diagram relative to the second filament light. This is visualized in FIG. 5.

[0032] According to the present disclosure, the light emitted by an LED filament is a combination of LED light and converted light. Therefore, the CCT of the light emitted by the LED filament can be selected by choosing any one or more parameters that affect the conversion characteristics of the LED light or the encapsulant. Similarly, the device light emitted by an LED filament device is a combination of a first LED filament light and a second LED filament light. Therefore, the device light can be selected by specifying any one or more parameters that affect any one or more of the first LED light, the second LED light, the conversion characteristics of the first encapsulant, and the conversion characteristics of the second encapsulant. As a result, the CCT of the LED filament device depends on CCT1, CCT2, and the intensities of the first LED filament light and the second LED filament light.

[0033] According to the present invention, each first LED is configured to emit a first LED light having a first peak wavelength λ1, and each second LED is configured to emit a second LED light having a second peak wavelength λ2. λ1 may be different from λ2 here. Each first LED may generally be configured to emit a first LED light having a first peak wavelength λ1 in the range of 430 to 494 nm, while each second LED may generally be configured to emit a second LED light having a second peak wavelength λ2 = 487 + / - 7 nm. In other words, each first LED may be configured to emit light in the blue to cyan range, while each second LED may be configured to emit cyan light. The term peak wavelength may be used interchangeably with the term dominant wavelength. λ2 is preferably selected to be λ2 = 487 + / - 6 nm, more preferably λ2 = 487 + / - 5 nm, and most preferably 487 + / - 4 nm.

[0034] In an embodiment of the present invention, λ1 = 450 + / - 20 nm, and λ2 - λ1 ≥ 20 nm. It has been found that these wavelengths make it possible to generate melanopic light while simultaneously providing device light with a high CCT. Melanopic light can be considered light within the wavelength range of 475 to 500 nm. A difference of at least 20 nm between λ1 and λ2, i.e., λ2 - λ1 ≥ 20 nm, is particularly preferred for obtaining device light with both a high CCT and additional melanopic light. In a preferred embodiment, λ2 - λ1 ≥ 25 nm, more preferably ≥ 30 nm, and most preferably ≥ 35 nm. For λ1, it is preferred that λ1 = 450 + / - 15 nm, more preferably λ1 = 450 + / - 12 nm, and most preferably λ1 = 445 + / - 10 nm.

[0035] In a specific embodiment of the present invention, λ1 = 487 + / - 7 nm and λ2 = 487 + / - 7 nm. Selecting λ1 = 487 + / - 7 nm and λ2 = 487 + / - 7 nm allows both the first and second LEDs to emit the same light. The first and second luminescent materials may be the same material; for example, the first and second luminescent materials may have the same ratio of green phosphor to red phosphor, or alternatively, the same ratio of yellow phosphor to red phosphor. Thus, A1 and A2 may be the same. To create a difference between CCT1 and CCT2, the thickness and / or concentration of the phosphor may be different between the first and second LED filaments. Selecting λ1 = 487 + / - 7 nm and λ2 = 487 + / - 7 nm allows both the first and second LED filaments to emit white light with a wide range of correlated color temperatures.

[0036] The difference between λ1 and λ2 can contribute to the first LED filament light having CCT1 and the second LED filament light having CCT2, as schematically visualized in FIG. 5 . Accordingly, a controller can be used to adjust the intensity of the first LED and the intensity of the second LED to adjust the ratio between the first LED filament light having CCT1 and the second LED filament light having CCT2. Because the combination of the first LED filament light and the second LED filament light constitutes the device light, a controller can therefore be used to adjust the CCT of the device light. Here, the intensity of either the first LED and / or the second LED can be adjusted, for example, by adjusting the power supplied to the first LED and / or the second LED.

[0037] The difference between CCT1 and CCT2 may be selected according to the invention so that CCT1≦CCT2−500K, which is preferred in order to provide a minimum adjustment of the CCT of the LED filament device. Preferably, CCT1≦CCT2−500K, more preferably, CCT1≦CCT2−1500K, and most preferably, CCT1≦CCT2−2000K.

[0038] In certain embodiments of the invention, CCT1 and CCT2 may be selected such that CCT1≦2500K and CCT2≧2700K. The device light may be configured to be adjusted between a third correlated color temperature CCT3 and a fourth correlated color temperature CCT4. CCT3 and CCT4 may be selected such that CCT3≦2500K, CCT4≧2700K, and CCT3≦(CCT4−500K). In other embodiments, CCT1, CCT2, CCT3, and CCT4 may be selected such that CCT1≦2300K, CCT3≦2300K, CCT2≧3000K, and CCT4≧3000K.

[0039] Referring to FIG. 2 , the first encapsulant 140 may have a first thickness T1, and the second encapsulant 190 may have a second thickness T2. The thickness of any encapsulant 140, 190 may be understood herein as the thickness of the encapsulant 140, 190 over any LED 130, 180, i.e., the thickness of the encapsulant 140, 190 may be understood as the shortest distance that light from the encapsulated LED 130, 180 of the filament 110, 160 must travel through the encapsulant 140, 190 before the light exits the filament 110, 160. According to an embodiment of the present invention, T1 and T2 may be selected such that T2≦0.8T1. It has been found that such a thickness difference allows for appropriate adjustment of the CCT of the device light.

[0040] According to the present disclosure, the first and second encapsulants may have a first light-off state color appearance and a second light-off state color appearance, respectively. The first and second light-off state color appearances may be generally referred to herein as A1 and A2. The light-off state color appearance of either encapsulant may be determined, for example, by the fluorescence and reflectance of the encapsulant. The light-off state color appearance of an encapsulant may be defined, for example, by the peak wavelength of light emerging from the encapsulant. Using the latter definition, A1 and A2 may be defined herein as the same if the peak wavelength of light emerging from the first encapsulant in the off state is within 15 nm, preferably within 10 nm, of the peak wavelength of light emerging from the second encapsulant. The light-off state color appearance of an encapsulant may alternatively be defined using CIE xy parameters. Using the latter definition, x may be defined herein as the peak wavelength of light emerging from the first encapsulant in the off state, preferably within 15 nm, preferably within 10 nm. A1 =x A2 ±1.0 and y A1 =y A2 In other examples, A1 and A2 may be defined to be the same when x is 0.01 to 0.01. A1 =x A2 ±0.5 and y A1 =y A2A1 and A2 may be defined to be the same when the difference is ±0.5. In another example, A1 may be considered the same as A2 when the first and second encapsulants have the same color, typically orange. The first and second encapsulants may also have the same hue, and more particularly, the first and second encapsulants may have the same colorfulness, chroma, and / or saturation.

[0041] According to an embodiment of the present invention, any one or more of the first luminescent material and the second luminescent material may each include a green and / or yellow phosphor and a red phosphor. In other words, any one or more of the first luminescent material and the second luminescent material may each include a green phosphor and a red phosphor, a yellow phosphor and a red phosphor, or a green phosphor, a yellow phosphor and a red phosphor. The green and / or yellow phosphor of the first luminescent material and the green and / or yellow phosphor of the second luminescent material may be different or the same. Additionally or optionally, the red phosphor of the first luminescent material and the red phosphor of the second luminescent material may be different or the same. The green and / or yellow phosphor may have, for example, a lower excitation intensity at λ2 than at λ1. The difference in excitation intensity at the first peak wavelength and the second peak wavelength may, in certain embodiments, be at least 20% of the peak excitation intensity of the green and / or yellow phosphor.

[0042] According to an embodiment of the present invention, any one or more of the first luminescent material and the second luminescent material is selected from the group consisting of A3B5O 12The first luminescent material and the second luminescent material may have a :Ce type luminescent material, where A may include one or more of Y, La, Gd, Tb, and Lu, B may include one or more of Al, Ga, In, and Sc, and O is oxygen. Any one or more of the first luminescent material and the second luminescent material may be, for example, yttrium aluminum garnet Y3Al5O. 12 , or gadolinium aluminum garnet Gd3Al5O 12 In another example, the first luminescent material and / or the second luminescent material may comprise a KSiF phosphor. In another example, the first luminescent material and / or the second luminescent material may comprise a LuAG phosphor. Those skilled in the art with knowledge of the present invention will understand that the first luminescent material and the second luminescent material may be selected, optionally in combination with λ1 and λ2, to determine the correlated color temperature range over which the LED filament device can be varied. According to any embodiment of the present invention, the device light may generally be white light having a correlated color temperature in the range of 1800 to 6500 K and a color rendering index of at least 80.

[0043] The LED filament device 100 may generally be part of an LED light bulb, an LED filament lamp 220, a lighting fixture 250, or the like. FIG. 3 schematically illustrates an LED filament lamp 220 including the LED filament device 100. The LED filament lamp 220 may further include an envelope 230 that at least partially surrounds the first LED filament 110 and the second LED filament 160, and a base 240 for electrically and mechanically connecting the LED filament lamp 220 to, for example, a socket of a lighting fixture 250. The envelope 230 may be a transparent material, such as a transparent ceramic or polymer. The base 240, sometimes referred to as a base, may be, for example, an Edison screw, e.g., E27, E14, or the like. FIG. 6 schematically illustrates a lighting fixture 250 including the LED filament device 100. As will be understood by those skilled in the art, the lighting fixture 250 may take a wide variety of shapes. The lighting fixture may include multiple LED filament devices 100, as schematically illustrated in FIG. 6.

[0044] The LED filament lamp 220 or lighting fixture may generally further comprise an antenna 260, as shown schematically in Fig. 3. The antenna here may be configured to communicate wirelessly with an external control unit or the like to provide instructions to the controller 210 of the filament device 100. The antenna 260 may therefore be considered to be configured to control the controller 210.

Claims

1. This is an LED filament device for supplying light to the device. A first LED filament configured to emit light having a first correlated color temperature CCT1, First carrier, A plurality of first LEDs arranged on the first carrier, each first LED configured to emit first LED light having a first peak wavelength λ1, and A first encapsulating material that encapsulates the plurality of first LEDs and at least partially covers the first carrier, comprising a first luminescent material configured to at least partially convert the light of the first LEDs into first converted light, wherein the first LED filament has a first encapsulating material having a first light source off-state color appearance A1, A second LED filament configured to emit light having a second correlated color temperature CCT2, Second carrier, A plurality of second LEDs arranged on the second carrier, each second LED configured to emit second LED light having a second peak wavelength λ2, and A second encapsulating material that encapsulates the plurality of second LEDs and at least partially covers the second carrier, comprising a second luminescent material configured to at least partially convert the second LED light into second converted light, wherein the second LED filament has a second encapsulating material having a second light source off-state color appearance A2, An LED filament apparatus including a controller for individually controlling the first LED filament light emitted by the first LED filament and the second LED filament light emitted by the second LED filament, such that the apparatus light is variable in correlated color temperature, An LED filament device in which λ1 is in the range of 430 to 470 nm, λ2 = 487 ± 7 nm, λ2 - λ1 ≥ 20 nm, CCT1 ≤ CCT2 - 500 K, and A1 and A2 are the same.

2. The LED filament apparatus according to claim 1, wherein CCT1 ≤ CCT2 - 1000K.

3. The LED filament apparatus according to claim 1 or 2, wherein the first encapsulant has a first thickness T1 and a first luminescence material concentration C1, and the second encapsulant has a second thickness T2 and a second luminescence material concentration C2, with T2 ≤ 0.8T1 and / or C2 ≤ 0.8C1.

4. The LED filament apparatus according to claim 1 or 2, wherein the first luminescent material comprises a green and / or yellow phosphor and a red phosphor, and the second luminescent material comprises a green and / or yellow phosphor and a red phosphor.

5. The LED filament apparatus according to claim 4, wherein the green and / or yellow phosphor of the first luminescence material and the green and / or yellow phosphor of the second luminescence material are the same, and optionally, the red phosphor of the first luminescence material and the red phosphor of the first luminescence material are the same.

6. The LED filament apparatus according to claim 4, wherein the green and / or yellow phosphor has an excitation intensity at the second peak wavelength λ2 that is lower than the excitation intensity at the first peak wavelength λ1.

7. The LED filament apparatus according to claim 4, wherein the difference in excitation intensity at the first peak wavelength and the second peak wavelength is at least 20% of the peak excitation intensity of the green and / or yellow phosphor.

8. The LED filament apparatus according to claim 1 or 2, wherein CCT1 ≤ 2500K and CCT2 ≥ 2700K, and preferably CCT1 is in the range of 800 to 2400K.

9. The LED filament apparatus according to claim 1 or 2, wherein the apparatus light is configured to be adjusted between a third correlated color temperature CCT3 and a fourth correlated color temperature CCT4, and CCT3 ≤ 2500K, CCT4 ≥ 2700K, and CCT3 ≤ (CCT4 - 500K).

10. The LED filament apparatus according to claim 9, wherein CCT1 ≤ 2300K, CCT3 ≤ 2300K, CCT2 ≥ 3000K, and CCT4 ≥ 3000K.

11. One or more of the first luminescent material and the second luminescent material are A ３ B ５ O １２ The LED filament apparatus according to claim 1 or 2, comprising a Ce-type luminescent material, wherein A comprises one or more of Y, La, Gd, Tb, and Lu, and B comprises one or more of Al, Ga, In, and Sc, and the apparatus light is white light having a correlated color temperature in the range of 1800 to 6500 K and a color rendering index of at least 80.

12. The LED filament apparatus according to claim 1 or 2, wherein one or more of the first luminescent material and the second luminescent material include a KSiF phosphor.

13. An LED filament lamp having the LED filament device according to claim 1 or 2, further comprising an envelope that at least partially surrounds the first LED filament and the second LED filament, a base for electrically and mechanically connecting the LED filament lamp to a socket of a lighting fixture, and an antenna for wirelessly controlling the controller.

14. A lighting fixture having an LED filament device as described in claim 1 or 2.

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