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EP-4739941-A1 - A LED FILAMENT LAMP BASED ON PHOSPHOR-CONVERTED GREEN LED FILAMENT AND HYBRID DIRECT-EMITTING RED-BLUE LED FILAMENT

EP4739941A1EP 4739941 A1EP4739941 A1EP 4739941A1EP-4739941-A1

Abstract

The LED filament lamp (1) is configured to provide lamp light emitting from a plurality of LED filaments (2, 3, 12). LED filament lamp (1) comprises a phosphor-converted green LED filament (2) and a hybrid direct-emitting red-blue LED filament (3). 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, in operation, emit first LED light being blue light. When the light emits from the blue or UV LEDs (91), the light is passing through the mixture of the greenish phosphor coating, wherein the converted light is mainly distributed in a part of the visible light spectrum as a green light. The first LED light is converted into a first converted light being only green light. The light emitted from the second LED filament (3) may be blue light or red light, or a light mixed with blue light or red light. The red-blue light emitted from the red- blue LED filament (3) stimulates the relative blue and red receptors of the eye, and the converted green light stimulates the green receptors of the eye, such that the resulting mix of converted green light, the blue and red light gives the appearance of a 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 emits white light with a variable color temperature or emits colored light.

Inventors

  • VAN BOMMEL, TIES
  • HIKMET, RIFAT, ATA, MUSTAFA

Assignees

  • Signify Holding B.V.

Dates

Publication Date
20260513
Application Date
20240624

Claims (15)

  1. 1. A LED filament lamp (1) providing lamp light, wherein the LED filament lamp (1) comprises: at least one first LED filament (2) emitting first LED filament light and comprises a first elongated carrier having a first major surface and a second major surface arranged opposite each other, wherein the first major surface is adapted to receive a plurality of first blue LEDs (9 1 ) configured to, in operation, emit first LED light being first blue light, wherein said first blue LEDs (9 1 ) are arranged in at least one first array on said first elongated carrier (7 1 ), wherein the plurality of first blue LEDs (9 1 ) is covered by a first elongated encapsulant (8 1 ) comprising a first luminescent material (8') configured to fully convert the first LED light into a first converted light, the first converted light being a first green light, such that the first LED filament (2) emits first green light; at least one second LED filament (3) emitting second LED filament light and comprises a second elongated carrier (7 2 ) having a third major surface and a fourth major surface arranged opposite each other, wherein the third major surface and the fourth major surface are adapted to receive: (i) a plurality of second blue LEDs (9 2 ) configured to, in operation, emit second LED light being second blue light, and (ii) a plurality of red LEDs (10) configured to, in operation, emit third LED light being first red light, wherein the plurality of second blue LEDs (9 2 ) and the plurality of red LEDs (10) are arranged in at least one second array on said second elongated carrier (7 2 ), such that the second LED filament (3) emits second blue light and first red light.
  2. 2. LED filament lamp (l)according to claim 1, wherein the at least one first LED filament (2) and the at least one second LED filament (3) are arranged at a distance, D, from one another, wherein D is at least 5mm.
  3. 3. 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 ) configured to, in operation, emit a fourth LED light being a third blue light, wherein the plurality of third blue LEDs (9 3 ) is arranged on said second major surface (11 2 ) of the first elongated carrier (7 1 ), wherein the plurality of third blue LEDs (9 3 ) is covered by a second elongated encapsulant (8 2 ) comprising a second luminescent material (8") configured to fully convert the fourth LED light into a second converted light, and wherein the second converted light is a second green light having a peak emission wavelength higher than a peak emission wavelength of the first converted light.
  4. 4. LED filament lamp (1) according to claim 1 or 2, and further comprising a third LED filament (13) configured to emit a third LED filament light, wherein the third LED filament (13) comprises a plurality of fourth blue LEDs (9 4 ) configured to, in operation, emit fifth LED light being third blue light, wherein the plurality of fourth blue LEDs (9 4 ) is arranged in at least one array on the third elongated carrier (7 3 ), wherein the plurality of fourth blue LEDs (9 4 ) is covered by a third encapsulant (8 3 ) comprising a third luminescent material configured to at least partially convert the fifth blue light into a third converted light, and wherein the third converted light is third green light, second red light or a combination of green light and red light.
  5. 5. LED filament lamp (1) according to any of the preceding claims, wherein: the plurality of second blue LEDs (9 2 ) and the plurality of red LEDs (10) are arranged altematingly on said third major surface (11 3 ) of the second elongated carrier (3), or the plurality of second blue LEDs (9 2 ) and the plurality of red LEDs (10) are arranged altematingly on said third major surface (11 3 ) and on said fourth major surface (11 4 ) of the second elongated carrier (3), wherein the fourth major surface is opposite to the first major surface, or the plurality of second blue LEDs (9 2 ) is arranged on said third major surface (11 3 ) of the second elongated carrier (3) and the plurality of red LEDs (10) are arranged on said fourth major surface (11 4 ) of the second elongated carrier (3).
  6. 6. LED filament lamp (1) according to any of the preceding claims, wherein the second LED filament (3) comprises a third encapsulant (8 3 ) comprising a light scattering material configured to scatter the second LED light into second scattered light and the third LED light into third scattered light, wherein said third encapsulant (8 3 ) covers said plurality of second blue LEDs (9 2 ) and said plurality of red LEDs (10).
  7. 7. LED filament lamp (1) according to any one of the preceding claims, wherein the one or more of the first elongated carrier (7 1 ), the second elongated carrier (7 2 ) and, where provided, the third elongated carrier (7 3 ) is translucent, and said respective elongated carriers are configured to at least partly transmit a LED light, which LED light comprises one or both of a direct light and a converted light.
  8. 8. LED filament lamp (1) according to any one of the preceding claims, wherein the first LED filament (2) is obliquely arranged with respect to the second LED filament (3), and wherein an axis of elongation (LI) of the first LED filament (2) and an axis of elongation (L2) of the second LED filament (3) are not arranged in a plane; and where provided, wherein the third LED filament (12) is obliquely arranged with respect to the second LED filament (3), and wherein an axis of elongation (L3) of the third LED filament (12) and an axis of elongation (L2) of the second LED filament (3) are not arranged in a plane.
  9. 9. LED filament lamp (1) according to any of the preceding claims, wherein said LED filament lamp comprises a light transmissive envelope (4) at least partly enclosing the first LED filament (2), the second LED filament (3) and, where provided, the third LED filament (13), wherein the envelope (4) and the respective LED filaments (2, 3,13) are arranged in electrically connection with at least one lamp connector configured for mechanically and electrically connecting to said LED filament lamp to a socket of a luminaire.
  10. 10. 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. 11. LED filament lamp (1) according to claim 10, wherein a cross-sectional shape of the envelope is circular, wherein the at least two first LED filaments and the at least two second LED filaments are arranged alternatingly and equally distributed around a center axis of the envelope (4).
  12. 12. 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 respective first major surface or the respective third major surface of the first LED filament and the second LED filament face each other, or the respective first major surface or the respective third major surface of the first LED filament and the second LED filament face an inner surface of the envelope, or the respective second major surface or the respective fourth major surface of the first LED filament and the second LED filament face away from a longitudinal axis of the LED filament lamp.
  13. 13. 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 where provided the third LED filament (12), comprises a longitudinal axis, and wherein the first LED filament (2), the second LED filament (3), and where provided the third LED filament (12) 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. 14. LED filament lamp (1) according to any of the preceding claims, wherein the LED filament lamp (1) further comprises a controller (6) configured to individually control each respective array of LEDs of each respective LED filament of the LED filament lamp separately, such that said controller (6) individually controls the first LED light emitted by said plurality of first blue LEDs (9 1 ), the second LED light emitted by said plurality of second blue LEDs (9 2 ) and the third LED light emitted by said plurality of red LEDs (10); and wherein the controller is configured control said first LED filament (2) and second LED filament (3), such that the lamp light in a first operational mode is only first LED light, in a second operational mode is only second LED light, in a third operational mode is only third LED light, and in a fourth operational mode is white lamp light having a correlated color temperature in a range from 1700K to 6500K and a color rendering index of at least 80.
  15. 15. LED filament lamp (1) according to claim 14, wherein the controller (6) is configured to individually control each respective array of LEDs of each respective LED filament (2, 3,12) of the LED filament lamp (1) separately, such that the lamp light emitted by the LED filament lamp (1) is varied from a first white lamp light having a first correlated color temperature (CCT1) to a second white lamp 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 more than 1000 K.

Description

A LED filament lamp based on phosphor-converted green LED filament and hybrid direct- emitting red-blue LED filament FIELD OF THE INVENTION The invention relates to LED filament lamp comprising at least two LED filaments, wherein the LED filament lamp comprises phosphor-converted LED filament and direct-emitting dual-color LED filament. BACKGROUND OF THE INVENTION A trend in lighting is LED filament lamps. An LED filament lamp, such as LED retrofit lamps or LED light bulbs, is a LED lamp which may 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 light-emitting diodes. LEDs filaments are available in all colors i.e., blue, green, red, and white LED filaments. Most commercially available LED retrofit lamps may include one or more LED filament that provide white light with a single-color temperature, wherein LED filaments typically include one type of LEDs, e.g., blue or UV LEDs, covered by a luminescent coating, e.g., a polymer layer comprising a yellowish phosphor coating capable of providing yellow converted light based on blue or UV LEDs. When the light emitting from the blue or UV LEDs, is passing through the mixture of the yellowish phosphor coating, the converted light is distributed in 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 mix of blue and yellow converted light gives the appearance of a white light. When controlling a white light emitting from the LED filament lamp, the LED filament lamp may be controllable between a warm white light and a cool white light, being accomplished 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 filament relative to the preferred white light. Alternatively, when controlling a white light emitting from the LED filament lamp, the LED filament lamp may be controlled between warm white light and a cool white light accomplished 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 filament and the red and blue light relative to the preferred white light. US 2021/0018146 Al discloses an LED light bulb for proving light distribution of the LED flexible filament light bulb. The LED light bulb comprise at least two filaments. Each of the filament is capable of emitting light with a different light characteristic from each other. The LED filament includes a linear array of LEDs arranged on a carrier substrate, wherein the linear array is divided into two separate longitudinal sections, a first longitudinal section including only LEDs configured to emit white light, and a second longitudinal section including only color controllable LEDs configured to emit color controllable light, said color controllable LEDs comprise LED groups each including a red LED, a green LED, and a blue LED. It is desired to improve the performance and/or the functionality of LED filaments for use in a LED filament lamp. SUMMARY OF THE INVENTION It is an object of the present invention to overcome this problem, and to improve performance and/or functionality of LED filaments for use in a LED filament lamp. These and other objects are achieved by providing a LED filament lamp configured to, in operation, provide lamp light, wherein the LED filament lamp comprises: at least one first LED filament emitting first LED filament light, and comprises a first elongated carrier having a first major surface and a second major surface arranged opposite each other, wherein the first major surface is adapted to receive a plurality of first blue LEDs configured to, in operation, emit first LED light being a first blue light, 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 encapsulant comprising a first luminescent material, configured to fully convert the first LED light into a first converted light, the first converted light being a first green light, such that the first LED filament (2) emits first green light at least one second LED filament emitting second LED filament light, and comprises a second elongated carrier having a third major surface and a fourth major surface arranged opposite each other, wherein the third major surface and/or the fourth major surface are adapted to receive: (i) a plurality of second blue LEDs configured to, in operation, emit second LED light being second blue light, and (ii) a plurality of red LEDs configured to, in operation, emit third LED light being first red light, wherein the plurality of second blue LEDs and the pluralit