LED filament lamp with green LED filaments based on phosphor conversion and mixed direct red-blue LED filaments

Abstract

The LED filament lamp (1) is configured to provide light emitted from a plurality of LED filaments (2, 3, 12). The LED filament lamp (1) comprises a green LED filament (2) for phosphor conversion and a red-blue LED filament (3) for mixed direct emission. The LED filament lamp (1) comprises at least one first LED filament (2) and at least one second LED filament (3). The first LED filament (2) comprises a plurality of first blue LEDs (91) configured to emit, in operation, first LED light as blue light. When light is emitted from a blue or UV LED (91), light passes through the mixture of light green phosphor coatings, where the converted light is distributed predominantly as green light in a portion of the visible spectrum. The first LED light is converted into first converted light that is only green light. The light emitted from the second LED filament (3) may be blue light or red light, or light mixed with blue light or red light. The red-blue light emitted from the red-blue LED filament (3) stimulates the opposite blue and red receptors of the eye and the converted green light stimulates the green receptors of the eye such that the resulting mixture of the converted green light, blue light and red light gives the appearance of white light. The white light may be controllable. The LED filaments (2, 3, 12) may be controllable such that the LED filaments (2, 3, 12) together emit white light with variable color temperature or colored light.

Description

TECHNICAL FIELD

[0001] The present invention relates to an LED filament lamp comprising at least two LED filaments, wherein the LED filament lamp comprises a phosphor-converted LED filament and a direct emitting bi-color LED filament. BACKGROUND

[0002] A trend in lighting is the LED filament lamp. An LED filament lamp, such as an LED retrofit lamp or LED bulb, is an LED lamp that can be designed to resemble a traditional incandescent light bulb, with a visible filament for aesthetic and light distribution purposes, but with the high efficiency of a light emitting diode. LED filaments are available in various colors, i.e. blue, green, red and white LED filaments.

[0003] Most commercially available LED retrofit lamps can comprise one or more LED filaments providing white light with a single color temperature, wherein the LED filament typically comprises one type of LED, e.g. a blue or UV LED, covered by a luminescent coating, e.g. a polymer layer comprising a yellowish phosphor coating capable of providing a yellow converted light based on the blue or UV LED. When the light emitted from the blue or UV LED passes through the mixture of the yellowish phosphor coating, the converted light is distributed over the entire visible spectrum. The blue light emitted from the LED filament stimulates the blue receptors of the eye and the yellow light stimulates the red and green receptors of the eye, such that the resulting mixture of blue and yellow converted light gives the appearance of white light.

[0004] When controlling the white light emitted from the LED filament lamp, the LED filament lamp can be controllable between warm white light and cool white light, by using a first LED filament emitting warm white light and a second LED filament emitting cool white light, and individually controlling the intensity of the individual LED filaments with respect to the preferred white light. Alternatively, when controlling the white light emitted from the LED filament lamp, the LED filament lamp can be controllable between warm white light and cool white light, realized using a first LED filament emitting warm white light and a second LED filament emitting additional red and blue light. And individually controlling the intensity of the individual LED filaments as well as the red and blue light with respect to the preferred white light.

[0005] US 2021 / 0018146 A1 discloses an LED bulb for proving a light distribution of an LED flexible filament bulb. The LED bulb comprises at least two filaments. Each filament is capable of emitting light having light properties different from each other. The LED filament comprises a linear array of LEDs arranged on a carrier substrate, wherein the linear array is divided into two separate longitudinal portions, a first longitudinal portion comprising only LEDs configured to emit white light, and a second longitudinal portion comprising only color controllable LEDs configured to emit color controllable light, said color controllable LEDs comprising LED groups, each LED group comprising a red LED, a green LED and a blue LED.

[0006] It is desirable to improve the performance and / or functionality of LED filaments for LED filament lamps. SUMMARY

[0007] It is an object of the present invention to overcome this problem and to improve the performance and / or functionality of LED filaments for use in LED filament lamps.

[0008] These and other objects are achieved by providing an LED filament lamp configured to provide light in operation, wherein the LED filament lamp comprises:

[0009] at least one first LED filament emitting a first LED filament light and comprising a first elongated carrier having a first main surface and a second main surface arranged opposite each other, wherein the first main surface is adapted to receive a plurality of first blue LEDs configured to emit a first LED light being a first blue light in operation, wherein said first blue LEDs are arranged in at least one first array on said first elongated carrier, wherein the plurality of first blue LEDs is covered by a first elongated encapsulation comprising a first luminescent material configured to convert the first LED light completely into a first converted light being a first green light, such that the first LED filament (2) emits the first green light

[0010] at least one second LED filament emitting a second LED filament light and comprising a second elongated carrier having a third main surface and a fourth main surface arranged opposite each other, wherein the third main surface and / or the fourth main surface is adapted to receive:

[0011] (i) a plurality of second blue LEDs configured to emit a second LED light being a second blue light in operation, and

[0012] (ii) a plurality of red LEDs configured to emit a third LED light being a first red light in operation,

[0013] wherein the plurality of second blue LEDs and the plurality of red LEDs are arranged in at least one second array on the second elongated carrier such that the second LED filament (3) emits second blue light and first red light.

[0014] The LED filament lamp is configured to provide light emitted from the various LED filaments. The LED filament lamp comprises a green phosphor converted LED filament and a directly emitting red-blue LED filament. The LED filament lamp comprises at least one first LED filament and at least one second LED filament. The first LED filament and the second LED filament are both elongated. When light is emitted from the blue or UV LED, the light passes through a mixture of e.g. a green phosphor coating comprising one or more green phosphors, wherein the converted light is predominantly distributed in a part of the visible light spectrum as green light. The red-blue light emitted from the red-blue LED filament stimulates the opposing blue and red receptors of the eye and the converted green light stimulates the green receptors of the eye, such that the combined mixture of converted green light, blue light and red light gives the appearance of white light.

[0015] Thereby, an improved performance and / or functionality of the LED filaments for the LED filament lamp is achieved.

[0016] The first LED filament comprises a plurality of first blue LEDs configured to emit, in operation, first LED light as blue light. The first blue LEDs can be configured to emit first blue light having a dominant peak wavelength in the wavelength range of 400 nm to 480 nm. The first blue LEDs are arranged in at least one first array on a first elongated carrier. The first elongated carrier comprises a first main surface and a second main surface configured to receive the LEDs. The first main surface and the second main surface are arranged such that the first main surface and the second main surface are opposite to each other. The plurality of first blue LEDs are arranged on one or both of the first main surface and the second main surface along the first elongated carrier. The first blue LEDs are covered by a first elongated encapsulant comprising a first luminescent material. The first elongated encapsulant can also at least partially cover at least one of the first main surface or the second main surface, such that at least a portion of the first main surface and optionally the second main surface can also be covered by the first elongated encapsulant comprising the first luminescent material. The encapsulant can be a polymeric material, which can be rigid or flexible.

[0017] The first luminescent material is configured to convert the first LED light completely into first converted light. The term "completely" is to be understood that at least 95% of the first LED light is converted. The converted light can preferably be 98% of the light emitted from the first blue LED. The converted light can more preferably be 99% of the light emitted from the first blue LED. The converted light is preferably 100% of the light emitted from the first blue LED. The first luminescent material is configured to convert the first LED light into first converted light that is first green light. The first LED light can be converted into first converted light that is green light only. The converted light converted from the first blue light emitted from the first blue LED can preferably have a dominant peak wavelength in the wavelength range from 510 nm to 580 nm as green light.

[0018] The second LED filament comprises a plurality of second blue LEDs configured to emit, in operation, second LED light that is second blue light, and a plurality of red LEDs configured to emit, in operation, third LED light that is red light. The second blue LEDs can be configured to emit second blue light having a dominant peak wavelength in the wavelength range from 400 nm to 480 nm. The red LEDs can be configured to emit third LED light that is first red light having a dominant peak wavelength in the wavelength range from 600 nm to 680 nm. The plurality of second blue LEDs and the plurality of red LEDs are arranged in at least one second array on a second elongated carrier. The second elongated carrier comprises a third major surface and a fourth major surface. The second elongated carrier comprises the third major surface and the fourth major surface configured to receive LEDs. The third major surface and the fourth major surface are arranged such that the third major surface and the fourth major surface are opposite each other. Light emitted from the second LED filament can emit second LED filament light that is second blue light or first red light, or light mixed with the second blue light and the first red light. The plurality of third blue LEDs are covered by a second encapsulant comprising a second luminescent material configured to at least partially convert the third blue light into second converted light, and wherein the second converted light is green light, red light, or a combination of green light and red light.

[0019] In an embodiment, the at least one first LED filament and the at least one second LED filament are arranged at a distance from each other, wherein the distance is at least 5 mm.

[0020] The at least one first LED filament and the at least one second LED filament, when arranged within the LED filament lamp, can be positioned such that they are at least or at an average distance from each other. This distance can be at least 5 mm. Preferably, it can be at least 10 mm. More preferably, it can be at least 13 mm. Most preferably, it can be at least 15 mm. The distance between the LED filaments can depend on the size and shape of the LED filament lamp. The distance between the LED filaments can depend on the size and shape of the LED filaments arranged within the LED filament lamp. The distance between the LED filaments can depend on the number of first and second filaments placed within the LED filament lamp.

[0021] Referring to the first and second LED filaments, the effects of the latter two embodiments are obtained, namely, reduced crosstalk, i.e., the first luminescent material (e.g., one or more green phosphors) is hardly excited or not excited by the blue light emitted by at least one second LED filament.

[0022] In one embodiment, the first LED filament further includes a plurality of third blue LEDs configured to emit fourth LED light as third blue light in operation, wherein the plurality of third blue LEDs are disposed on the second main surface of the first elongated carrier opposite the first main surface, wherein the plurality of third blue LEDs are covered by a second elongated encapsulation comprising a second luminescent material configured to completely convert the fourth LED light into second converted light, and wherein the second converted light is second green light having a peak emission wavelength higher than that of the first converted light.

[0023] Multiple first blue LEDs may be arranged on a first main surface of a first elongated carrier. The first LED filament also includes multiple third blue LEDs configured to emit fourth LED light as a third blue light during operation. Multiple third blue LEDs may be arranged on a second main surface of the first elongated carrier opposite to the first main surface.

[0024] Multiple third blue LEDs may be covered by a second elongated package, which includes a second luminescent material configured to completely convert the light from the fourth LEDs into second converted light. The second converted light is a second green light with a peak emission wavelength higher than that of the first converted light.

[0025] In one embodiment, the LED filament lamp further includes a third LED filament configured to emit third LED filament light, wherein the third LED filament includes a plurality of fourth blue LEDs configured to emit fifth LED light as third blue light in operation, wherein the plurality of fourth blue LEDs are arranged in at least one array on a third elongated carrier, wherein the plurality of fourth blue LEDs are covered by a third encapsulation comprising a third luminescent material, the third luminescent material being configured to at least partially convert the third blue light into third converted light, and wherein the third converted light is green light, red light, or a combination of green and red light.

[0026] The third LED filament includes a plurality of fourth blue LEDs configured to emit fifth LED light as third blue light during operation. The fourth blue LEDs can be configured to emit fifth LED light having a dominant peak wavelength in the wavelength range of 400 nm to 480 nm. The dominant peak wavelength of the fifth LED light can be equal to or different from the dominant peak wavelength of one of the first, second, or fourth LED lights. The plurality of fourth blue LEDs can be arranged in at least one array on a third elongated carrier. The plurality of fourth blue LEDs can be completely or partially covered by a third encapsulation comprising a third luminescent material. The third luminescent material converts the fifth LED light, or part of the fifth LED light, into third converted light. The third converted light can be third green light in the wavelength range of 500 nm to 580 nm. The third converted light can also be red light in the wavelength range of 400 nm to 480 nm. The third converted light can also be a combination of additional green and red light. When the plurality of fourth blue LEDs are partially covered by the third encapsulation comprising the third luminescent material, the third filament can emit the fifth LED light, the converted green light, and the red light. The third filament can be configured to provide white light.

[0027] In one embodiment, a plurality of second blue LEDs and a plurality of red LEDs are alternately arranged on the third main surface of the second elongated carrier, or a plurality of second blue LEDs and a plurality of red LEDs are alternately arranged on the third main surface and the fourth main surface of the second elongated carrier, or a plurality of second blue LEDs are arranged on the third main surface of the second elongated carrier and a plurality of red LEDs are arranged on the fourth main surface of the second elongated carrier.

[0028] Multiple second blue LEDs and multiple red LEDs can be alternately arranged on the third main surface of the second elongated carrier. Multiple second blue LEDs and multiple red LEDs can also be alternately arranged on the fourth main surface of the second elongated carrier, opposite the third main surface. Alternatively, multiple second blue LEDs and multiple red LEDs can be alternately arranged on both the third and fourth main surfaces of the second elongated carrier, with the second blue LEDs arranged on the third main surface and the red LEDs arranged on the fourth main surface.

[0029] In one embodiment, the second LED filament includes a third encapsulation comprising a light-scattering material configured to scatter the second LED light into a second scattered light and the third LED light into a third scattered light, wherein the third encapsulation covers the plurality of second blue LEDs and the plurality of red LEDs.

[0030] The second LED filament may include a third encapsulation comprising a light-scattering material. The third encapsulation may not contain any light-emitting material. Therefore, the second LED filament may not contain any light-emitting material. The light-scattering material may be configured to scatter the light from the second LED into second scattered light and the light from the third LED into third scattered light. The third encapsulation completely or partially covers a plurality of second blue LEDs and a plurality of red LEDs. The light-scattering material can provide second scattered light as blue scattered light. The light-scattering material can provide third scattered light as red scattered light.

[0031] In one embodiment, one or more of the first elongated carrier, the second elongated carrier, and the third elongated carrier are translucent, and each elongated carrier is configured to at least partially transmit LED light, which includes direct light and / or converted light.

[0032] One or more of the first elongated carrier, the second elongated carrier, and, if configured, the third elongated carrier, may be translucent. One or more carriers may be reflective or translucent. One or more carriers may be translucent. One or more carriers are preferably transparent. One or more carriers may be rigid, for example, made of polymer, glass, quartz, metal, or sapphire. Alternatively, one or more carriers may be flexible, for example, made of polymer or metal, such as a film or foil or the like.

[0033] In one embodiment, the first LED filament is arranged obliquely relative to the second LED filament, and the elongation axes of the first LED filament and the second LED filament are not arranged in a plane; and in another embodiment, the third LED filament is arranged obliquely relative to the second LED filament, and the elongation axes of the third LED filament and the second LED filament are not arranged in a plane.

[0034] The first LED filament can be arranged at an angle relative to the second LED filament. Preferably, the elongation axes of the first and second LED filaments are not arranged in similar planes. When a third LED filament is provided, the third LED filament can be arranged at an angle relative to the second LED filament, and wherein the elongation axes of the third LED filament and the second LED filament are not arranged in the same or parallel planes. When a third LED filament is provided, the third LED filament can be arranged at an angle relative to the first and second LED filaments, and wherein the elongation axis of the third LED filament, preferably the elongation axes of the first and second LED filaments, is not arranged in a plane. The resulting effect further reduces crosstalk.

[0035] One or more of the first LED filament, the second LED filament, and, in some configurations, the third LED filament, may be arranged at an angle relative to the longitudinal direction of the LED filament lamp. Alternatively, the first LED filament, the second LED filament, and, in some configurations, the third LED filament, may be arranged at different angles relative to the longitudinal direction of the LED filament lamp.

[0036] In one embodiment, the LED filament lamp includes a light-transmitting housing that at least partially surrounds a first LED filament, a second LED filament, and, in some cases, a third LED filament, wherein the housing and the respective LED filaments are arranged to be electrically connected to at least one lamp connector configured to mechanically and electrically connect the LED filament lamp to a socket of a luminaire.

[0037] The LED lamp includes a light-transmitting housing that at least partially surrounds a first LED filament, a second LED filament, and, in some configurations, a third LED filament. The housing may be arranged to contact at least one connector configured to mechanically connect the LED filament lamp to a receptacle of a luminaire. Each LED filament is arranged to contact at least one connector configured to mechanically and electrically connect the LED filament lamp to the receptacle of the luminaire. The LED filament lamp may include a base member. The base member may be a connector. The housing and each LED filament are arranged to contact the base member for connecting the LED filament lamp to the receptacle of the luminaire.

[0038] In one embodiment, the LED filament lamp includes at least two first LED filaments and at least two second LED filaments.

[0039] An LED filament lamp includes at least two first LED filaments and at least two second LED filaments. The LED filament lamp may also include at least two third LED filaments. Alternatively, the LED filament lamp may include at least three first LED filaments and at least three second LED filaments. The LED filament lamp may also include at least three third LED filaments. The at least two first LED filaments, the at least two second LED filaments, and, when present, the at least two third LED filaments are arranged to be spaced apart from each other by a distance D, where D may be at least 7 mm. The at least two first LED filaments, the at least two second LED filaments, and, when present, the at least two third LED filaments are arranged to be approximately uniformly distributed within the LED filament lamp.

[0040] In one embodiment, the cross-sectional shape of the housing is circular, wherein at least two first LED filaments and at least two second LED filaments are arranged alternately and equally around the central axis of the housing.

[0041] The cross-sectional shape of the housing can be circular. The at least two first LED filaments and the at least two second LED filaments can be arranged alternately and equally around the central axis of the housing. The at least two first LED filaments and the at least two second LED filaments, and when at least two third LED filaments are provided, can be arranged alternately and equally around the central axis of the housing.

[0042] In one embodiment, a first LED filament and a second LED filament are arranged in an LED filament lamp such that the corresponding first main surface or corresponding third main surface of the first LED filament and the second LED filament face each other, or the corresponding first main surface or corresponding third main surface of the first LED filament and the second LED filament face the inner surface of the housing, or the corresponding second main surface or corresponding fourth main surface of the first LED filament and the second LED filament face the inner surface of the housing.

[0043] A first LED filament and a second LED filament can be arranged in an LED filament lamp such that their respective first main surfaces or respective third main surfaces face each other. Alternatively, the respective first main surfaces or respective third main surfaces of the first and second LED filaments face the inner surface of the housing. Alternatively, the respective second main surfaces or respective fourth main surfaces of the first and second LED filaments face the inner surface of the housing. A second blue LED, configured to emit blue light during operation, can face away from the central axis of the housing. The central axis of the housing can be similar to the longitudinal axis of the LED filament lamp. The central axis of the housing can be parallel to the longitudinal axis of the LED filament lamp.

[0044] In an embodiment, each of the first LED filament, the second LED filament, and, in some cases, the third LED filament, includes a longitudinal axis, and wherein the first LED filament, the second LED filament, and the provided third LED filament are arranged such that the respective longitudinal axes of at least the first LED filament and the second LED filament extend in different planes.

[0045] The first LED filament has a first longitudinal axis, which extends in a first plane. This first longitudinal axis can be arranged in a position parallel to or at an angle relative to the longitudinal axis of the LED filament lamp. The second LED filament has a second longitudinal axis, which extends in a second plane. This second longitudinal axis can be arranged in a position parallel to or at an angle relative to the longitudinal axis of the LED filament lamp. The second longitudinal axis can be arranged in a position parallel to or at an angle relative to the first longitudinal axis. In the case of a third LED filament, the third LED filament includes a third longitudinal axis extending in a third plane. This third longitudinal axis can be arranged in a position parallel to or at an angle relative to the longitudinal axis of the LED filament lamp. The third longitudinal axis can be arranged in a position parallel to or at an angle relative to the respective first and second longitudinal axes. The first LED filament, the second LED filament, and, in the case provided, the third LED filament, can be arranged such that at least the corresponding longitudinal axes of the first LED filament, the second LED filament, and the third filament extend in the same plane or in different planes.

[0046] In one embodiment, the LED filament lamp further includes a controller configured to individually control each corresponding LED array of each corresponding LED filament of the LED filament lamp, such that the controller individually controls first LED light emitted by the plurality of first blue LEDs, second LED light emitted by the plurality of second blue LEDs, and third LED light emitted by the plurality of red LEDs, and the controller is configured to control the first LED filament and the second LED filament such that the light in a first operating mode is only the first LED light, the light in a second operating mode is only the second LED light, the light in a third operating mode is only the third LED light, and in a fourth operating mode is white light having a correlated color temperature in the range of 1700K to 6500K and a color rendering index of at least 80.

[0047] LED filament lamps can be controlled using internal or external controllers. An internal controller can be located inside the LED filament, for example, in the base. An external controller can control the internal controller wirelessly or via a wired connection. The controller can be configured to individually control each corresponding LED array of each corresponding LED filament in the LED filament lamp. When the LEDs are electrically controlled, the controller individually controls the intensity of the LED light emitted by multiple LEDs. Specifically, the controller individually controls the intensity of the first LED light emitted by the multiple first blue LEDs, the intensity of the second LED light emitted by the multiple second blue LEDs, and the intensity of the third LED light emitted by the multiple red LEDs.

[0048] The controller can control the first LED filament and the second LED filament, such that in the first operating mode, the light emitted from the LED filament lamp can be solely the light from the first LED. By using the term "solely," it should be understood that in the first operating mode, at least 95% of the light can be the light from the first LED. Preferably, 98% of the light can be the light from the first LED. More preferably, 99% of the light can be the light from the first LED. Most preferably, 100% of the light can be the light from the first LED.

[0049] In the second operating mode, the light emitted from the LED filament lamp may be solely the light emitted by the second LED. By using the term "solely," it should be understood that in the second operating mode, at least 95% of the light may be the second LED light. Preferably, 98% of the light may be the second LED light. More preferably, 99% of the light may be the second LED light. Most preferably, 100% of the light may be the second LED light.

[0050] In the third operating mode, the light emitted from the LED filament lamp can be solely the third LED light. By using the term "solely," it should be understood that in the third operating mode, at least 95% of the light can be the third LED light. Preferably, 98% of the lamp can be the third LED light. More preferably, 99% of the light can be the third LED light. Most preferably, 100% of the light can be the third LED light.

[0051] In the fourth operating mode, the light emitted from the LED filament lamp can be white light with a correlated color temperature in the range of 1700K to 6500K, and the color rendering index (CRI) of the white light is at least 80. Preferably, the CRI of the white light is at least 85. More preferably, the white light has a CRI of at least 90. Most preferably, the white light has a CRI greater than 95.

[0052] In one embodiment, the controller is configured to individually control each corresponding LED array of each corresponding LED filament of the LED filament lamp, such that the light emitted by the LED filament lamp changes from a first white light having a first correlated color temperature CCT1 to a second white light having a second correlated color temperature CCT2, wherein the difference between the first and second correlated color temperatures, CCT2-CCT1, is ≥1000K.

[0053] The controller can be further configured to control each corresponding LED array of each corresponding LED filament of the LED filament lamp individually, such that the light emitted by the LED filament lamp varies between the following:

[0054] - White light with a color temperature in the range of 1800K to 6500K, or

[0055] - The first light including the first dominant peak wavelength in the blue wavelength range of 430nm to 495nm, or

[0056] - The second light includes a second dominant peak wavelength in the green / yellow wavelength range of 500nm to 595nm, or

[0057] - The third light includes the third dominant peak wavelength in the red wavelength range of 600nm to 695nm.

[0058] Alternatively, the light emitted by the LED filament lamp can be varied within the following steps:

[0059] - White light has a color temperature in the range of 1800K to 3000K, or

[0060] - White light has a color temperature in the range of 3500K to 4500K, or

[0061] White light has a color temperature ranging from 5000K to 6500K.

[0062] The controller can be configured to control each corresponding LED array of each corresponding LED filament of the LED filament lamp individually, so that the light emitted by the LED filament lamp can be changed.

[0063] The light emitted from the LED filament lamp can be white light with a color temperature in the range of 1700K to 6500K. Preferably, the light emitted from the LED filament lamp can vary within the steps of white light with a color temperature in the range of 1800K to 3000K, white light with a color temperature in the range of 3500K to 4500K, or white light with a color temperature in the range of 5000K to 6500K. The light emitted from the LED filament lamp can be white light with a color temperature in the range of 1800K to 6500K. The white light can include a first light having a first dominant peak wavelength in the blue wavelength range of 430nm to 495nm. The white light can also include a second light having a second dominant peak wavelength in the green / yellow wavelength range of 500nm to 595nm, and, when present, the white light can also include a third light having a third dominant peak wavelength in the red wavelength range of 600nm to 695nm.

[0064] The light emitted from the LED filament lamp can also vary between a first light, a second light, or a third light. The first light includes a first dominant peak wavelength in the blue wavelength range of 430nm to 495nm, the second light includes a second dominant peak wavelength in the green / yellow wavelength range of 500nm to 595nm, and the third light includes a third dominant peak wavelength in the red wavelength range of 600nm to 695nm.

[0065] The LED filaments can be controllable, so that the LED filaments together emit white light with a color temperature in the range of 1800-3000K, preferably in the range of 2000-2700K, more preferably in the range of 2100-2400K, and most preferably in the range of 2150-2350K.

[0066] The LED filaments can also be controllable, allowing them to emit white light with a color temperature ranging from 3500-5000K, preferably from 3500-4500K, more preferably from 3700-4300K, and most preferably from 3800-4200K. The LED filaments can also be controllable, allowing them to emit white light with a color temperature ranging from 5000-7000K, preferably from 5500-6500K, more preferably from 5700-6300K, and most preferably from 5800-6200K. The color temperature of the emitted light can be controlled by adjusting the relative intensity of each type of LED. The light can be controlled to change the color temperature steplessly or in 500K increments. The light can be controlled to change the color temperature preferably in 250K increments.

[0067] The light can be controlled so that the color temperature changes more preferably in 100K increments. The light can also be controlled so that the color temperature changes most preferably in 50K increments. White light can change its color temperature substantially along a blackbody trajectory or along a line perpendicular to the blackbody trajectory according to a predetermined color temperature.

[0068] It should be noted that the present invention relates to all possible combinations of the features described in the claims. Attached Figure Description

[0069] This and other aspects of the invention will now be described in more detail with reference to the accompanying drawings, which illustrate embodiments of the invention.

[0070] Figure 1 A schematic side view of an LED filament lamp is shown.

[0071] Figure 2a and Figure 2b A schematic side view of an LED filament is shown.

[0072] Figure 3a and Figure 3b A schematic cross-sectional view showing the position of the LED filament in an LED filament lamp is shown.

[0073] Figure 4 The different variations of light emitted from five LED filaments are shown.

[0074] Figure 5 A schematic side view of the first, second, and third LED filaments is shown.

[0075] Figure 6a and Figure 6b A schematic side view of the first and second LED filaments is shown.

[0076] As shown in the figures, the dimensions of the layers and regions have been enlarged for illustrative purposes; therefore, the dimensions of the layers and regions are provided to illustrate the general structure of embodiments of the present invention. The same reference numerals consistently denote the same elements. Detailed Implementation

[0077] The invention will now be described more fully below with reference to the accompanying drawings, in which presently preferred embodiments of the invention are illustrated. However, the invention may 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 to fully convey the scope of the invention to those skilled in the art.

[0078] Figure 1 A schematic side view of an LED filament lamp 1 is shown. The LED filament lamp 1 includes a housing 4 and a base 5. The LED filament lamp 1 includes a first LED filament 2 and a second LED filament 3. The LED filament lamp 1 may include a light-transmitting housing 4 surrounding the first LED filament 2 and the second LED filament 3. The housing 4 and the corresponding LED filaments 2, 3 are arranged to contact the base 5. The first LED filament 2 and the second LED filament 3 are mechanically and electrically connected to the base 5. The base 5 is configured such that the LED filament lamp 1 can be connected to a socket of a luminaire. The housing 4 includes a central axis. The central axis of the housing 4 is parallel to the longitudinal axis X1 of the LED filament lamp 1. Figure 1 The shape of the LED filament lamp 1 shown can be referred to as a classic filament LED bulb or a modified bulb. The LED filament lamp 1 includes at least one first LED filament 2 (such as a phosphor-converted green LED filament) and a second LED filament 3 (such as a direct-emission bicolor LED filament). The LED filaments 2 and 3 can be arranged parallel to each other and extend along the longitudinal axis X1 of the LED filament lamp 1.

[0079] The first LED filament 2 and the second LED filament 3 are arranged at a distance D from each other within the LED filament lamp 1. The distance D between the LED filaments 2 and 3 can depend on the size and shape of the LED filament lamp 1. The distance D between the LED filaments 2 and 3 can depend on the size and shape of the LED filaments 2 and 3 arranged inside the LED filament lamp 1. The distance D between the LED filaments 2 and 3 can depend on the number of the first and second filaments 2 and 3 that can be placed inside the LED filament lamp 1.

[0080] The LED filament lamp 1 also includes a controller 6. The controller 6 is configured to individually control each corresponding LED array of each corresponding LED filament 2, 3 of the LED filament lamp 1.

[0081] Figure 2a and Figure 2b Two different schematic side views of an LED filament are shown. Figure 2aIt is shown to include a first main surface 11 1 Second main surface 11 2 The LED filament is carried by a slender carrier 7. In this example, LED 9 1 9 n 10 is arranged on the first main surface 11 1 Above. The slender carrier 7 has a longitudinal direction that defines the longitudinal axis X2 ( Figure 2a (The arrow in the image). The elongated carrier 7 may be translucent. One or more elongated carriers 7 may be reflective or translucent, for example, translucent, preferably transparent. The elongated carrier 7 is covered by an elongated encapsulation 8. The elongated encapsulation 8 includes a light-emitting material. The light-emitting material is configured to convert light into converted light, which is essentially converted green light. For example, the light-emitting material includes a phosphor conversion material, such that light emitted from the LED is converted into green light. Alternatively, the LED filaments 2, 3 may include a carrier 7 covered by an encapsulation 8 including a light-scattering material. The light-scattering material is configured to scatter LED light into diffused light.

[0082] See also Figure 2b The first LED filament 2 includes multiple LEDs configured to emit LED light as green conversion light during operation. The second LED filament 3 includes multiple LEDs 9. 1 10, these LEDs 9 1 LED filament 1 is configured to emit LED light as a colored light during operation, which is either blue or red light. Alternatively, the second LED filament 3 is configured to emit a third LED light during operation, which is, for example, a second blue light and a first red light. The light emitted from LED filament lamp 1 can be controlled to be dimmable, allowing the light to change between different color temperatures during use. Controller 6 can control each corresponding LED array of each corresponding LED filament of the LED filament lamp individually, making it possible to change the light emitted by the LED filament lamp. LED filament lamp 1 can emit white light providing a color temperature in the range of 1800K to 3000K. LED filament lamp 1 can also emit white light providing a color temperature in the range of 3500K to 4500K. LED filament lamp 1 can also emit white light providing a color temperature in the range of 5000K to 6500K.

[0083] Figure 3a and Figure 3b Two different schematic cross-sectional views are shown illustrating the possible positions of the LED filaments in the LED filament lamp 1 according to the present invention. The LED filament lamp 1 includes a plurality of first LED filaments 2 and a plurality of second LED filaments 3 arranged alternately along the circumference of the housing of the LED filament lamp 1. Figure 3aIn the illustrated embodiment, the LED filament lamp 1 includes three first LED filaments 2 and three second LED filaments arranged alternately along the circumference of the outer casing of the LED filament lamp 1. Figure 3b In the illustrated embodiment, the LED filament lamp 1 includes two first LED filaments 2 and two second LED filaments arranged alternately along the circumference of the lamp's housing. When arranged inside the LED filament lamp 1, the first and second filaments 2 and 3 are equidistant from each other by a distance D. The distance D between the individual LED filaments 2 and 3 depends on the size and shape of the LED filament lamp 1. The distance D between the LED filaments 2 and 3 can also depend on the size and shape of the LED filaments 2 and 3 arranged inside the LED filament lamp 1. The distance D between the LED filaments can also depend on the number of first and second filaments 2 and 3 placed inside the LED filament lamp 1.

[0084] Figure 4 Five different variations of light emitted from five LED filaments are shown. Light 12 emitted from LED filament lamp 1. 1 The first change can be the green light provided by the first LED filament 2. The LED light 12 emitted from the LED filament lamp 1... 2 The second variation can be the warm white light provided by the first and second LED filaments 2 and 3 together. The light 12 emitted from the LED filament lamp 1... 3 The third variation can be cool white light provided by the first and second LED filaments 2 and 3 together. Light 12 emitted from LED filament lamp 1 4 The fourth change could be the red light provided by the second LED filament 3. The light 12 emitted from the LED filament lamp 1... 5 The fifth variation could be blue light, also provided by the second LED filament 3.

[0085] Figure 5 A schematic side view of a first LED filament 2, a second LED filament 3, and a third LED filament 13 is shown. The LED filament lamp 1 may therefore also include a third LED filament 13. The third LED filament 13 may include a plurality of fourth blue LEDs configured to emit a fifth LED light as a third blue light in operation. The plurality of fourth blue LEDs may be covered by a third encapsulation comprising a third luminescent material configured to at least partially convert the third blue light into third converted light. The third converted light may be green light, red light, or a combination of green and red light. The LED filament lamp 1 may include a first LED filament 2, a second LED filament 3, and a third LED filament 13 when configured. The LED filament lamp 1 may be configured to provide light emitted from a combination of multiple LED filaments emitting multiple wavelength ranges. Each LED filament is arranged to contact at least one connector configured to mechanically and electrically connect the LED filament lamp to a socket of the luminaire.

[0086] Figure 6a and Figure 6b A schematic side view of two different embodiments of first and second LED filaments 2 and 3 is shown. The first LED filament 2 includes a first elongated carrier, such as... Figure 2a As shown, it has a first main surface 111 and a second main surface 11 arranged opposite to each other. 2 First primary surface 11 1 Second main surface 11 2 Suitable for accommodating multiple first blue LEDs 9 1 First blue LED 9 1 The first LED to emit blue light. First blue LED 9 1 It can be configured to emit first blue light with a dominant peak wavelength in the wavelength range from 400nm to 480nm. Multiple first blue LEDs 9 1 Composed of a first encapsulation containing a first luminescent material 8 1 Coverage. The first luminescent material passes through the first encapsulation 8 1 The first LED light is converted into the first converted light. The first converted light is green light with a main peak wavelength in the range of 510nm to 580nm.

[0087] The second LED filament 3 has a second carrier 7, which includes a third main surface and a fourth main surface arranged opposite to each other. The second carrier 7 includes a third main surface configured to receive LED 10 and a main surface configured to receive LED 9. 2 The fourth main surface. Multiple second blue LEDs 9 2 Multiple red LEDs 10 are arranged in at least one second array on the second carrier 7. Multiple second blue LEDs 9... 2 The second LED emits blue light. (Second blue LED 9) 2 A second blue light can be emitted, having a dominant peak wavelength in the wavelength range of 400 nm to 480 nm. Multiple red LEDs 10 emit a third LED light as red light. The red LEDs can be configured to emit the third LED light having a dominant peak wavelength in the wavelength range of 600 nm to 680 nm. The light emitted from the second LED filament can be blue light, red light, or a mixture of blue and red light.

[0088] Figure 6a The first example is shown on the left side, featuring multiple second blue LEDs (9). 1 Multiple red LEDs 10 and second LED filaments 3 are alternately arranged on the third main surface. Multiple second blue LEDs 9 1Multiple red LEDs 10 are alternately arranged on the third main surface of the second elongated carrier 7, and, if present, on the fourth main surface. Figure 6a The right side shows a second example, which has multiple second blue LEDs 9 1 The second LED filament 3 is arranged on the side of the second carrier 7, i.e., the third main surface. Multiple red LEDs 10 are arranged on the opposite side of the second carrier 7, i.e., the fourth main surface.

[0089] Figure 6b A first example is shown, wherein the first LED filament 2 comprises two packages 8 having first and second light-emitting materials 8', 8" that are different from each other. 1 8 2 The second LED filament may include multiple second blue LEDs. 1 And multiple red LEDs 10 are arranged relative to each other, as if combined Figure 6a As described. Multiple first blue LEDs 9 1 It is arranged on the first main surface of the first elongated carrier. The first LED filament 2 also includes multiple third blue LEDs 9. 3 The third blue LED 9 3 It can emit a fourth LED light. The third blue LED is 9. 3 It can emit light similar to the first blue LED 9. 1 The first light. Multiple third blue LEDs (9) 3 Arranged on the second main surface of the first carrier. Multiple third blue LEDs 9 3 It can be encapsulated by a second elongated package 8 2 Coverage. Second elongated package 8 2 It can be different from the second elongated package 8 1 The second elongated package 8 2 It may include a second light-emitting material 8". The second light-emitting material 8" may be different from the first light-emitting material 8'. The second light-emitting material 8" can convert the fourth LED light into a second converted light. The second converted light may be green light with a peak emission wavelength higher than that of the first converted light.

[0090] Those skilled in the art will recognize that the present invention is by no means limited to the preferred embodiments described above. Rather, many modifications and variations are possible within the scope of the appended claims.

[0091] Furthermore, by studying the accompanying drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement variations of the disclosed embodiments in practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. The fact that certain measures are recited in mutually different dependent claims does not imply that combinations of these measures cannot be advantageously used.

Claims

1. An LED filament lamp (1) for providing light, wherein the LED filament lamp (1) comprises: - At least one first LED filament (2) emits first LED filament light and includes a first elongated carrier having a first main surface and a second main surface arranged opposite to each other, wherein the first main surface is adapted to receive a plurality of first blue LEDs (9) 1 ), the plurality of first blue LEDs (9 1 ) is configured to emit a first LED light as a first blue light during operation, wherein the first blue LED (9 1 ) is arranged on the first elongated carrier (7) 1 In at least one first array on ), wherein the plurality of first blue LEDs (9 1 ) by the first elongated encapsulation (8 1 ) covering, the first elongated package (8 1 The first LED filament (2) includes a first light-emitting material (8') configured to completely convert the first LED light into a first converted light, wherein the first converted light is a first green light, causing the first LED filament (2) to emit the first green light. - At least one second LED filament (3), emitting light from the second LED filament and including a second elongated carrier (7) 2 The second elongated carrier has a third main surface and a fourth main surface arranged opposite to each other, wherein the third main surface and the fourth main surface are adapted to receive: (i) Multiple second blue LEDs (9 2 ), configured to emit a second LED light as a second blue light during operation, and (ii) Multiple red LEDs (10) are configured to emit a third LED light as a first red light during operation. -wherein the plurality of second blue LEDs (9 2 The plurality of red LEDs (10) are arranged on the second elongated carrier (7). 2 In at least one second array on the LED, the second LED filament (3) emits a second blue light and a first red light.

2. The LED filament lamp (1) according to claim 1, wherein the at least one first LED filament (2) and the at least one second LED filament (3) are arranged to be spaced apart from each other by a distance D, wherein D is at least 5 mm.

3. The LED filament lamp (1) according to claim 1 or 2, wherein the first LED filament (2) further comprises a plurality of third blue LEDs (9) 3 ), the plurality of third blue LEDs (9 3 ) is configured to emit a fourth LED light as a third blue light during operation, wherein the plurality of third blue LEDs (9 3 ) is arranged on the first elongated carrier (7) 1 The second main surface (11) 2 On, wherein the plurality of third blue LEDs (9 3 ) consisting of a second elongated encapsulation (8") including a second luminescent material (8") 2 The second luminescent material is configured to completely convert the fourth LED light into a second converted light, wherein the second converted light is a second green light with a peak emission wavelength higher than that of the first converted light.

4. The LED filament lamp (1) according to claim 1 or 2, further comprising a third LED filament (13) configured to emit third LED filament light, wherein the third LED filament (13) comprises a plurality of fourth blue LEDs (9). 4 ), the plurality of fourth blue LEDs (9 4 ) is configured to emit a fifth LED light as a third blue light during operation, wherein the plurality of fourth blue LEDs (9 4 ) is arranged in the third slender carrier (7) 3 In at least one array on ), wherein the plurality of fourth blue LEDs (9 4 ) by a third encapsulation (8 3 ) covering, the third encapsulation (8 3 The material includes a third luminescent material configured to at least partially convert the fifth blue light into a third converted light, wherein the third converted light is a third green light, a second red light, or a combination of green and red light.

5. The LED filament lamp (1) according to any one of the preceding claims, wherein: -The plurality of second blue LEDs (9) 2 The plurality of red LEDs (10) are alternately arranged on the third main surface (11) of the second elongated carrier (3). 3 On, or -The plurality of second blue LEDs (9) 2 The plurality of red LEDs (10) are alternately arranged on the third main surface (11) of the second elongated carrier (3). 3 On the first main surface (1) and the fourth main surface (114), wherein the fourth main surface is opposite to the first main surface, or -The plurality of second blue LEDs (9) 2 The third main surface (11) of the second elongated carrier (3) is arranged on the third main surface (11). 3 The plurality of red LEDs (10) are arranged on the fourth main surface (11) of the second elongated carrier (3), and the plurality of red LEDs (10) are arranged on the fourth main surface (11) of the second elongated carrier (3). 4 )superior.

6. The LED filament lamp (1) according to any one of the preceding claims, wherein the second LED filament (3) comprises a third package (8) 3 ), the third package (8 3 The third encapsulation includes a light-scattering material configured to scatter the light from the second LED into a second scattered light and the light from the third LED into a third scattered light, wherein the third encapsulation (8) 3 ) covering the plurality of second blue LEDs (9 2 ) and the plurality of red LEDs (10).

7. The LED filament lamp (1) according to any one of the preceding claims, wherein the first elongated carrier (7) 1 ), the second slender carrier (7) 2 ) and the third elongated carrier (7) in the configured case 3 One or more of the components are translucent, and the corresponding elongated carrier is configured to at least partially transmit LED light, the LED light comprising one or both of direct light and converted light.

8. The LED filament lamp (1) according to any one of the preceding claims, wherein the first LED filament (2) is arranged obliquely relative to the second LED filament (3), and wherein the elongation axis (L1) of the first LED filament (2) and the elongation axis (L2) of the second LED filament (3) are not arranged in a plane; and In the configuration, the third LED filament (12) is arranged at an angle relative to the second LED filament (3), and the elongation axis (L3) of the third LED filament (12) and the elongation axis (L2) of the second LED filament (3) are not arranged in a plane.

9. The LED filament lamp (1) according to any one of the preceding claims, wherein the LED filament lamp includes a light-transmitting housing (4) that at least partially surrounds the first LED filament (2), the second LED filament (3), and, in the case of an arrangement, the third LED filament (13), wherein the housing (4) and the corresponding LED filaments (2, 3, 13) are arranged to be electrically connected to at least one lamp connector configured to mechanically and electrically connect the LED filament lamp to a socket of a luminaire.

10. The LED filament lamp (1) according to any one of the preceding claims, wherein the LED filament lamp comprises at least two first LED filaments (2) and at least two second LED filaments (3).

11. The LED filament lamp (1) according to claim 10, wherein the cross-sectional shape of the housing is circular, wherein the at least two first LED filaments and the at least two second LED filaments are arranged alternately and equally around the central axis of the housing (4).

12. The LED filament lamp (1) according to any one of the preceding claims, wherein: - The first LED filament and the second LED filament are arranged in the LED filament lamp such that the corresponding first main surface or the corresponding third main surface of the first LED filament and the second LED filament face each other, or - The corresponding first main surface or the corresponding third main surface of the first LED filament and the second LED filament face the inner surface of the housing, or - The corresponding second main surface or the corresponding fourth main surface of the first LED filament and the second LED filament are opposite to the longitudinal axis of the LED filament lamp.

13. The LED filament lamp (1) according to any one of the preceding claims, wherein each of the first LED filament (2), the second LED filament (3) and the third LED filament (12) in the case of the arrangement includes a longitudinal axis, and wherein the first LED filament (2), the second LED filament (3) and the third LED filament (12) in the case of the arrangement are arranged such that the respective longitudinal axes of at least the first LED filament (2) and the second LED filament (3) extend in different planes.

14. The LED filament lamp (1) according to any one of the preceding claims, wherein the LED filament lamp (1) further comprises a controller (6), the controller (6) being configured to individually control each corresponding LED array of each corresponding LED filament of the LED filament lamp, such that the controller (6) individually controls each of the plurality of first blue LEDs (9 1 The first LED light emitted by the plurality of second blue LEDs (9) is further emitted by the plurality of second blue LEDs (9) 2 The second LED light emitted by the plurality of red LEDs (10) and the third LED light emitted by the plurality of red LEDs (10); and The controller is configured to control the first LED filament (2) and the second LED filament (3) such that the light in the first operating mode is only the light of the first LED, the light in the second operating mode is only the light of the second LED, the light in the third operating mode is only the light of the third LED, and the light in the fourth operating mode is white light with a correlated color temperature in the range of 1700K to 6500K and a color rendering index of at least 80.

15. The LED filament lamp (1) according to claim 14, wherein the controller (6) is configured to individually control each respective LED array of each respective LED filament (2, 3, 12) of the LED filament lamp (1), such that the light emitted by the LED filament lamp (1) changes from a first white light having a first correlated color temperature (CCT1) to a second white light having a second correlated color temperature (CCT2), wherein the difference between the first correlated color temperature and the second correlated color temperature is equal to or greater than 1000K.

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