LED filament comprising LEDs arranged to emit NIR light

Abstract

A light emitting diode, LED, filament configured to emit LED filament light is provided. The LED filament includes a carrier and an array of a plurality of light emitting diodes (LEDs) disposed on the carrier. The LED filament includes an encapsulant at least partially surrounding the array and at least partially surrounding the carrier. Each of the plurality of LEDs is disposed to emit LED light including at least one of purple light, blue light, cyan light, and red light. The package includes a near infrared (NIR) phosphor configured to convert at least a portion of the LED light emitted from the plurality of LEDs into NIR converted light, the NIR converted light having an NIR main peak wavelength [lambda] 5 in a wavelength range of 700 to 1400 nm, where the LED filament light includes the NIR converted light.

Description

Technical Field

[0001] The present invention generally relates to light emitting diode (LED) filaments. More particularly, the present invention relates to LED filaments arranged to emit near-infrared (NIR) light. Background Art

[0002] The use of light-emitting diodes (LEDs) for lighting purposes continues to gain attention. Compared to incandescent lamps, fluorescent lamps, neon lamps, etc., LEDs offer many advantages, such as longer operating life, reduced power consumption, and improved efficiency related to the ratio between light energy and heat energy. In particular, LED filament lamps are highly popular because they are very decorative.

[0003] Due to the advantages of using LEDs, interest in replacing traditional light sources with LEDs is rapidly increasing in many lighting fixtures. It should be understood that this replacement, also known as retrofitting, is popular and desirable among users who want the appearance of an incandescent bulb. Light source replacement (retrofitting) is typically performed by removing the conventional light source from the fixture (e.g., a lamp holder) of a lighting fixture and attaching an LED, LED device, or LED fixture to the fixture. One of these concepts is based on an LED filament placed in a bulb, as the appearance of such a lamp is highly decorative.

[0004] Furthermore, it is of interest to combine the advantageous properties of LED filaments, as described above for aesthetics and light distribution purposes, with the advantageous properties of near-infrared (NIR) lighting. It is understood that NIR lighting has many health benefits and has become a subject of renewed interest. For example, NIR light (700nm-1400nm) can be used to heal wounds, relieve pain, and potentially aid male infertility and other medical conditions, while being safe, non-invasive, and painless.

[0005] It is therefore an object of the present invention to combine the advantageous properties of LEDs with regard to energy efficiency and light distribution purposes with the advantageous properties of NIR lighting. Summary of the Invention

[0006] It is interesting to combine the advantageous properties of LEDs with regard to energy efficiency, light distribution purposes and / or aesthetics with the advantageous properties of near infrared (NIR) lighting.

[0007] This and other objects are achieved by providing an LED filament having the features of the independent claim.Preferred embodiments are defined in the dependent claims.

[0008] Therefore, according to the present invention, a light-emitting diode (LED) filament is provided, which is configured to emit LED filament light. The LED filament includes a carrier and an array of multiple light-emitting diodes (LEDs) arranged on the carrier. The LED filament also includes an encapsulation that at least partially surrounds the array of multiple LEDs and at least partially surrounds the carrier. Each of the multiple LEDs is arranged to emit LED light, and the LED light includes at least one of the following: violet light having a violet main peak wavelength λ1 within a wavelength range of 380 nm to 420 nm, blue light having a blue main peak wavelength λ2 within a wavelength range of 420 nm to 470 nm, cyan light having a cyan main peak wavelength λ3 within a wavelength range of 470 nm to 520 nm, and red light having a red main peak wavelength λ4 within a wavelength range of 600 nm to 660 nm. The package includes a near-infrared (NIR) phosphor configured to convert at least a portion of LED light emitted from the plurality of LEDs into NIR converted light having an NIR main peak wavelength λ5 within a wavelength range of 700 nm to 1400 nm, wherein the LED filament light includes the NIR converted light.

[0009] The present invention is therefore based on the concept of providing an LED filament comprising an array of LEDs, wherein each LED is arranged to emit LED light comprising at least one of violet light (380nm to 420nm), blue light (420nm to 470nm), cyan light (470nm to 520nm), and red light (600nm to 660nm), and wherein the array is at least partially encapsulated and / or surrounded by an encapsulant that includes an NIR phosphor configured to convert at least a portion of the LED light into NIR light (700nm to 1400nm). In other words, an LED filament is provided that emits NIR light or a combination of NIR light and LED light in the range of 380nm to 660nm. Thus, the LED filament is able to provide the advantageous characteristics of LED lighting in terms of energy efficiency and light distribution, while efficiently and safely providing NIR light, which has numerous health benefits, by emitting LED light in the visible range of 380nm to 660nm and converting the LED light into NIR light using an NIR phosphor.

[0010] The present invention has the advantage of providing NIR light in the wavelength range of 700 nm to 1400 nm by emitting LED light in the wavelength range of 380 nm to 660 nm and converting it into NIR light using an NIR phosphor. In other words, NIR light can be provided without having a light source that directly emits NIR light. Therefore, the present invention can benefit from using less expensive and more commonly available LED lamps that emit visible light to emit NIR light.

[0011] The present inventors will recognize that the LED filaments of the present invention can provide decorative and aesthetically pleasing visible LED light while providing NIR light having health benefits.

[0012] An advantage of the present invention is that the array of multiple LEDs of the LED filament allows for an uncomplicated and convenient circuit system, which in turn increases the service life of the LED filament and / or reduces the risk of failure of the LED filament during operation.

[0013] The advantage of the present invention is that the LED is relatively small, and the LED filament providing NIR light can be smaller than the traditional NIR light. Therefore, the NIR LED filament of the present invention can be more convenient and versatile.

[0014] An advantage of the present invention is that violet light having a main peak wavelength λ1 in the wavelength range of 380nm-420nm, for example 380nm-400nm or 400nm-420nm, is invisible to humans. Another advantage of the present invention is that the red main peak wavelength λ4 in the wavelength range of 600nm to 660nm can provide high energy efficiency (particularly in the wavelength range of 600nm to 630nm) and / or increased health benefits (particularly in the wavelength range of 630nm to 660nm). Another advantage of the present invention is that the NIR main peak wavelength λ5 in the wavelength range of 700nm-1400nm can provide relatively high energy efficiency (particularly in the wavelength range of 700nm-900nm) and / or increased health benefits (particularly in the wavelength range of 900nm-1200nm).

[0015] It should also be understood that the LED filament of the present invention also includes relatively few components. This relatively small number of components is advantageous because LED filaments are relatively inexpensive to manufacture. Furthermore, the relatively small number of components of an LED filament means it is easier to recycle, particularly when compared to devices or apparatuses that include a relatively large number of components, which hinder easy disassembly and / or recycling operations.

[0016] An LED filament configured to emit LED filament light includes a carrier. The term "carrier" herein refers to a component, substrate, printed circuit board, PCB, etc., that is arranged to mechanically and / or electrically support the LED. Thus, the plurality of LEDs can be arranged, mounted, and / or mechanically coupled to the carrier (e.g., substrate), wherein the carrier is configured to mechanically and / or electrically support the LED.

[0017] An LED filament includes an array of multiple LEDs arranged on a carrier. Each of the multiple LEDs can be a direct-emitting LED. "Array" refers to a regular order or arrangement, such as a series. The LEDs are arranged in a specific position and order relative to one another. For example, the LEDs can be arranged in a linear array on the carrier.

[0018] The LED filament includes an encapsulant that is configured / arranged to at least partially encapsulate / surround the plurality of LEDs and at least partially surround / cover the carrier. It should be understood that the encapsulant can completely surround the array of the plurality of LEDs. The term "encapsulant" herein refers to a material, element, arrangement, etc. that is configured or arranged to at least partially surround, encapsulate and / or surround the linear array. Each LED in the plurality of LEDs is arranged to emit LED light that includes at least one of the following: violet light having a violet main peak wavelength λ1, blue light having a blue main peak wavelength λ2, cyan light having a cyan main peak wavelength λ3, and red light having a red main peak wavelength λ4. "Main peak wavelength" herein refers to the centroid peak wavelength, that is, the wavelength at which the light reaches maximum intensity.

[0019] The package includes a near-infrared (NIR) phosphor configured to convert at least a portion of LED light emitted from the plurality of LEDs into NIR-converted light having an NIR dominant peak wavelength λ5, wherein the LED filament light includes the NIR-converted light. A phosphor is a substance / material that exhibits luminescence, i.e., emits light when exposed to a certain type of radiant energy, such as LED light.

[0020] In one or more embodiments, the plurality of LEDs of the array may be electrically connected in series (ie, in a series circuit system).

[0021] According to one embodiment of the present invention, the carrier comprises a first main surface and a second main surface opposite the first main surface, and the encapsulant comprises a first encapsulant that at least partially surrounds the array of the plurality of LEDs and at least partially covers the first main surface and comprises the NIR phosphor. In other words, the carrier has at least two main surfaces arranged opposite each other, wherein the first encapsulant at least partially surrounds the first main surface.

[0022] According to one embodiment of the present invention, the carrier is light-transmissive, wherein the carrier comprises a first major surface and a second major surface opposite the first major surface, and wherein the encapsulant comprises a second encapsulant that at least partially covers the second major surface and comprises an NIR phosphor. The term "light-transmissive" herein means that the carrier comprises a transparent and / or translucent material, composition, and / or substance that allows light to be transmitted through the carrier. An advantage of this embodiment is that the LED filament light can emit LED light and / or NIR light from the first and second major surfaces. For example, the light and / or NIR light can be emitted in opposite directions and / or in all directions.

[0023] According to one embodiment of the present invention, the encapsulant includes a first encapsulant that at least partially surrounds an array of multiple LEDs and at least partially covers a first major surface, wherein the first encapsulant includes a light scattering material that is configured to scatter at least a portion of the LED light emitted from the multiple LEDs through the carrier. The term "light scattering material" herein basically refers to any material that is configured or arranged to scatter (LED) light incident on the material. An advantage of this embodiment is that the LED light emitted from the multiple LEDs is at least partially transmitted through the carrier and emitted in more directions. This can provide more diffuse light and / or more aesthetically pleasing light.

[0024] According to one embodiment of the present invention, a first encapsulant includes a visible light phosphor configured to convert at least a portion of LED light emitted from a plurality of LEDs into converted visible light having a main peak wavelength λ6 within a wavelength range of 420 nm to 700 nm, wherein the LED filament light includes the converted visible light. This embodiment has the advantage that the LED filament lamp can be more decorative and / or aesthetically pleasing.

[0025] According to one embodiment of the present invention, the LED filament light includes at least one of violet, blue, cyan, and red light. This embodiment is advantageous in that the LED filament provides NIR light, which has health benefits, as well as violet, blue, cyan, and / or red visible light. The violet, blue, cyan, and / or red light in the LED filament light can enhance the beneficial effects of the NIR-converted light. For example, violet light can be used for disinfection and / or skin treatment purposes, such as treating acne. Blue light is advantageous given its health benefits, as it can enhance alertness, aid memory and cognitive function, and more. Furthermore, blue light regulates circadian rhythms, the body's natural wake-sleep cycle. Therefore, daytime exposure to blue light helps maintain a healthy circadian rhythm. Cyan light therapy can help kill bacteria that cause skin conditions such as acne, reduce redness and / or inflammation, and stimulate collagen and elastin production in the skin. Furthermore, red light therapy is being promoted as a treatment for several common skin conditions, including improved wound healing and the reduction of stretch marks, wrinkles, fine lines, and age spots. Furthermore, exposure to red light can lead to improvements in facial texture, reducing the effects of psoriasis, rosacea, eczema, scarring, sun-damaged skin, and the like. This embodiment can also be advantageous because LED filament lights can be more decorative and / or aesthetically pleasing. For example, red light can simulate NIR-converted light. Another advantage of this embodiment is that the LED filament light includes visible light that can indicate where the NIR light is being emitted.

[0026] According to one embodiment of the present invention, the NIR phosphor is configured to convert 20% to 80% of the LED light emitted from the plurality of LEDs, and wherein the LED filament light includes NIR-converted light and violet light. This embodiment is advantageous in that this ratio between visible violet light and NIR light in the LED filament light can result in a more decorative and / or aesthetically appealing light.

[0027] According to one embodiment of the present invention, the NIR phosphor is configured to convert 20% to 80% of the LED light emitted from the plurality of LEDs, and wherein the LED filament light includes NIR-converted light and blue light. This embodiment is advantageous in that this ratio between the visible blue light and the NIR light in the LED filament light can result in a more decorative and / or aesthetically pleasing light.

[0028] According to an embodiment of the present invention, the NIR phosphor is configured to convert 20% to 80% of the LED light emitted from the plurality of LEDs, wherein the LED filament light comprises both NIR-converted light and cyan light. This embodiment is advantageous in that this ratio between the visible cyan light and the NIR light in the LED filament light further contributes to the decorative aspect of the emitted light.

[0029] According to an embodiment of the present invention, the NIR phosphor is configured to convert 20% to 80% of the LED light emitted from the plurality of LEDs, and wherein the LED filament light includes both NIR-converted light and red light. This embodiment is advantageous because this ratio of visible red light to NIR light in the LED filament light can even result in a more decorative and / or aesthetically pleasing light.

[0030] According to one embodiment of the present invention, a plurality of LEDs are arranged to emit at least two of violet light, blue light, cyan light, and red light, and the LED filament light includes at least one of violet light, blue light, cyan light, and red light. An advantage of this embodiment is that when the LED filament light includes NIR light and two different visible light wavelengths of different colors, the LED filament light can be more decorative and / or aesthetically pleasing.

[0031] According to one embodiment of the present invention, the NIR phosphor is configured to fully convert a first light from among violet, blue, cyan, and red light, and to convert at least a portion of a second light from among violet, blue, cyan, and red light, where the second light is different from the first light. This embodiment has the advantage that the LED filament can be more versatile in terms of LED color, which can be used for desired and aesthetically pleasing effects. Another advantage of this embodiment is that the LED filament light can include two of the violet, blue, cyan, and red light, and at least a portion of these two lights can be converted into NIR light.

[0032] According to one embodiment of the present invention, the LED filament light comprises white light having a correlated color temperature (CCT) in the range of 1800K to 6500K and a color rendering index (CRI) of at least 80. An advantage of this embodiment is that the LED filament light may be more decorative and / or aesthetically pleasing.

[0033] According to one embodiment of the present invention, there is provided an LED filament arrangement comprising an LED filament according to any of the preceding embodiments, wherein the plurality of LEDs comprises at least two of the following: at least one violet LED, at least one blue LED, at least one cyan LED, and at least one red LED, wherein the LED filament arrangement comprises a controller configured to individually control at least two of the following: the at least one violet LED, the at least one blue LED, the at least one cyan LED, and the at least one red LED. For example, the LED filament arrangement may comprise at least one violet LED and at least one blue LED, such that the plurality of LEDs emit light having two different wavelengths, and wherein the controller may individually control each of the plurality of LEDs.

[0034] According to one embodiment of the present invention, an LED filament lamp is provided. The LED filament lamp comprises an LED filament according to any of the aforementioned embodiments or an LED filament arrangement according to any of the aforementioned embodiments. The LED filament lamp further comprises a light-transmitting (preferably transparent) housing at least partially surrounding the LED filament or the LED filament arrangement, and a base, wherein the base comprises a cap arranged to mechanically and electrically connect the LED lamp to a socket of a lamp fixture.

[0035] Other objects, features and advantages of the present invention will become apparent when studying the following detailed disclosure, the drawings and the appended claims.Those skilled in the art will realize that different features of the present invention can be combined to create embodiments other than those described in the following. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiments of the invention.

[0037] Figure 1a to Figure 1b Schematically shows an LED filament according to an exemplary embodiment of the present invention,

[0038] Figure 1c The distribution of LED light of an LED filament according to an exemplary embodiment of the present invention is schematically disclosed.

[0039] Figure 2 Schematically illustrates an LED filament according to an exemplary embodiment of the present invention,

[0040] Figure 3 schematically illustrates an LED filament arrangement according to an exemplary embodiment of the present invention, and

[0041] Figure 4 An LED filament lamp according to an exemplary embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0042] Figure 1a to Figure 1b An LED filament 100 according to an exemplary embodiment of the present invention is schematically shown. FIG1A shows a side view of the LED filament 100, Figure 1b A top view of the same LED filament 100 is shown. The LED filament 100 is configured to emit LED filament light 105. Preferably, the LED filament 100 has a length L (not shown) and a width W (not shown), where L>5 W. The LED filament 100 can be arranged in a straight configuration or a non-straight configuration, such as, for example, a bent configuration, a 2D / 3D spiral, or a helix.

[0043] The LED filament 100 includes a carrier 110 and an array 120 of a plurality of light-emitting diodes (LEDs) arranged on the carrier 110. The carrier 110 can be rigid (e.g., made of a polymer, glass, quartz, metal, or sapphire) or flexible (e.g., made of a polymer or metal, such as a film or foil). Each LED in the array 120 is arranged to emit LED light comprising at least one of violet light, blue light, cyan light, and red light. The violet light may have a violet primary peak wavelength λ1 within a wavelength range of 380 nm to 420 nm. The blue light may have a blue primary peak wavelength λ2 within a wavelength range of 420 nm to 470 nm. The cyan light may have a cyan primary peak wavelength λ3 within a wavelength range of 470 nm to 520 nm. The red light may have a red primary peak wavelength λ4 within a wavelength range of 600 nm to 660 nm.

[0044] The LED filament 100 further includes an encapsulant 130, wherein the encapsulant 130 at least partially surrounds the array 120 and at least partially surrounds the carrier 110. The encapsulant 130 includes a near-infrared (NIR) phosphor 132. The NIR phosphor 132 is configured to convert at least a portion of the LED light emitted from the plurality of LEDs into NIR light 135. The NIR light 135 may have an NIR main peak wavelength λ5 within a wavelength range of 700 nm to 1400 nm.

[0045] The NIR phosphor 132 may be configured to convert at least a portion of at least one of blue, cyan, purple, and red light into NIR light. Examples of NIR phosphors include, but are not limited to, K3LuSi2O7:0.01Eu 2+ (which can be excited, for example, with blue LED light), ScBO3:Cr 3+ (which can be excited, for example, with blue, cyan and / or red LED light), LiInSiO6:Cr 3+ (e.g. can be excited with blue, cyan and / or red LED light), La2MgZrO6:Cr 3+ (e.g. can be excited by blue, cyan and / or red LED light) and Y 3-x Ca x Al 5-x Si x O 12 :Cr 3+ (x=0-2.0) (which can be excited, for example, with violet, blue, cyan and / or red LED light). The NIR converted phosphor light preferably has a relatively wide full width at half maximum (FWHM), for example ≥90 nm or ≥120 nm, or even ≥150 nm.

[0046] FIG1C schematically illustrates the distribution of LED light provided by LED filament 100, with intensity (y-axis, arbitrary units) as a function of wavelength (x-axis, arbitrary units). Violet light 121 has a first dominant peak wavelength λ1 within the wavelength range of 380-420 nm. Blue light 122 has a second dominant peak wavelength λ2 within the wavelength range of 420 nm to 470 nm. For example, the dominant blue wavelength λ2 can be within the wavelength range of 420 nm to 430 nm, or within the wavelength range of 430 nm to 460 nm (e.g., royal blue light), or within the wavelength range of 460 nm to 470 nm (e.g., for melanopsin illumination).

[0047] The cyan light 123 has a third main peak wavelength λ3 within a wavelength range of 470 nm to 520 nm. For example, the cyan main peak wavelength λ3 may be within a wavelength range of 470 nm to 490 nm, or may be within a wavelength range of 490 nm to 520 nm.

[0048] The red light 124 has a fourth main peak wavelength λ4 in the wavelength range of 600 nm to 660 nm. It should be understood that the intensities I1, I2, I3, and I4 may be the same or different.

[0049] Figure 2 An LED filament 100 according to an exemplary embodiment of the present invention is schematically shown. It should be noted that Figure 2 The LED filament 100 shown in FIG. Figure 1a to Figure 1b The LED filament 100 shown in FIG. 1 has several features in common with the LED filament 100 shown in FIG. 1 , and to increase understanding of the features and / or functions of the LED filament 100, reference is made here to FIG. Figure 1a to Figure 1b and related text. LED filament 100 is configured to emit LED filament light 105. LED filament 100 includes a carrier 110 and an array 120 of a plurality of LEDs arranged on carrier 110. Each LED in array 120 is arranged to emit LED light 125, which includes at least one of violet light, blue light, cyan light, and red light. The different colors of LED light 125 can have a relatively narrow Full Width at Half Maximum (FWHM), for example, ≤40 nm or ≤25 nm.

[0050] exist Figure 2 , the carrier 110 includes a first major surface 112 and a second major surface 114. The second major surface 114 is arranged opposite the first major surface 112. The first and second major surfaces 112, 114 can be the front and back sides of the planar carrier 110. The carrier 110 is light-transmissive and allows light emitted from the plurality of LEDs of the array 120 to be transmitted through the carrier 110, such that the light is at least partially emitted in a direction normal to the second major surface 114.

[0051] LED filament 100 also includes an encapsulant 130, which includes a first encapsulant 134 and a second encapsulant 136. First encapsulant 134 at least partially surrounds array 120 and at least partially covers / surrounds first major surface 112. First encapsulant 134 includes a NIR phosphor 132 configured to convert at least a portion of LED light 125 emitted from the plurality of LEDs into NIR light. NIR phosphor 132 can be configured to fully convert all of LED light 125 into NIR light, such that LED filament light 105 includes only NIR light, i.e., without the blue, cyan, violet, and red light emitted by the plurality of LEDs. Second encapsulant 136 at least partially covers / surrounds second major surface 114. It should be understood that one or more, but not all, of the LEDs in array 120 may be external to encapsulant 130. It should be understood that one or more, but not all, of the LEDs in array 120 may be disposed external to first encapsulant 134. Alternatively, all of the LEDs in the plurality of LEDs are surrounded by the first encapsulant 134. Furthermore, the first major surface 112 may be completely surrounded by the first encapsulant 134, or a portion of the first major surface 112 may be enclosed by the first encapsulant 134. Similarly, the second major surface 114 may be completely or partially surrounded by the second encapsulant 136.

[0052] First encapsulant 134 may include a light-scattering material configured to scatter at least a portion of LED light 125 emitted from the plurality of LEDs through carrier 110. In other words, some light emitted from array 120 is reflected / scattered by first encapsulant 134 and transmitted through carrier 110. At least a portion of the scattered light transmitted through carrier 110 may be transmitted through second encapsulant 136. The light-scattering material may include a silicone matrix having at least one of Al2O3, BaSO4, TiO2, SiO2, CaF2, CaCO3, and BaTiO3 particles. Second encapsulant 136 may include NIR phosphor 132. Second encapsulant 136 may be configured to convert at least a portion of any transmitted scattered LED light 125 into NIR light.

[0053] The NIR phosphor 132 of the first encapsulant 134 and / or the second encapsulant 136 can be configured to convert 20% to 80% of the LED light 125 emitted from the plurality of LEDs and / or transmitted by the first encapsulant 134 into NIR light. In other words, the NIR phosphor 132 can be configured to convert 20% to 80% of any of the blue light, cyan light, violet light, and red light emitted by the plurality of LEDs. Thus, the LED filament light 105 can include NIR light and / or at least one of the blue, cyan, violet, and red light.

[0054] First encapsulant 134 may include a visible light phosphor configured to convert at least a portion of LED light 125 into visible light having a dominant peak wavelength λ6 within a wavelength range of 420 nm to 700 nm. The visible light phosphor may be configured to convert at least a portion of LED light 125 into visible light having a dominant peak wavelength λ6 that is higher than the dominant peak wavelengths λ1, λ2, λ3, and / or λ4 of LED light 125. For example, array 120 may include LEDs configured to emit blue light, and first encapsulant 134 may include a visible light phosphor configured to convert at least a portion of the LED light into any type of visible light, and an NIR phosphor 132 configured to convert at least a portion of the LED light into NIR light. LED filament light 105 may include NIR light and at least one of violet, blue, cyan, and red light of LED light 125. LED filament light 105 may include NIR light, and at least one of violet light, blue light, cyan light, and red light, and also include visible light converted from LED light 125 by a visible light phosphor.

[0055] Figure 3 Schematically shows an LED filament device 200 according to an exemplary embodiment of the present invention. The LED filament device 200 includes an LED filament 100. It should be noted that Figure 3 The LED filament 100 shown in FIG. Figure 1a to Figure 1b and Figure 2 The LED filament 100 has several features identical to those shown in FIG. Figure 1a to Figure 1b and Figure 2 , and related text to enhance understanding of some features and / or functionality of LED filament 100. LED filament 100 is configured to emit LED filament light 105. LED filament 100 includes a carrier 110 having first and second major surfaces 112, 114. LED filament 100 includes an array 120 of a plurality of LEDs disposed on carrier 110. Each LED in array 120 is configured to emit LED light 125, including at least one of violet light, blue light, cyan light, and red light. LED filament 100 includes first and second encapsulants 134, 136.

[0056] exist Figure 3, array 120 includes a first group of LEDs 120a and a second group of LEDs 120b, wherein the first group of LEDs 120a emits different LED light than the second group of LEDs 120b. For example, the first group of LEDs 120a may emit blue light, and the second group of LEDs 120b may emit red light. In other words, the first group of LEDs 120b may emit at least one of: violet light having a violet primary peak wavelength λ1 within the wavelength range of 380 nm to 420 nm, blue light having a blue primary peak wavelength λ2 within the wavelength range of 420 nm to 470 nm, cyan light having a cyan primary peak wavelength λ3 within the wavelength range of 470 nm to 520 nm, and red light having a red primary peak wavelength λ4 within the wavelength range of 600 nm to 660 nm. It should be understood that the array 120 of multiple LEDs may emit one, two, three, or all of the following: blue light, cyan light, violet light, and red light.

[0057] LED filament 100 includes a first encapsulant 134 that at least partially surrounds array 120 and first major surface 112 of carrier 110, and a second encapsulant 136 that at least partially surrounds second major surface 114 of carrier 110. The first encapsulant includes a NIR phosphor 132. The second encapsulant 136 may include NIR phosphor 132. NIR phosphor 132 is configured to fully convert a first light of violet, blue, cyan, and red light, and to convert at least a portion of a second light of violet, blue, cyan, and red light, wherein the second light is different from the first light. LED filament light 105 may include NIR light, and LED light 125 may include one, two, or more of blue, cyan, violet, and red light. LED filament light 105 may include white light having a correlated color temperature (CCT) in the range of 1500K to 8000K and a color rendering index (CRI) of at least 70. NIR phosphor 132 and the plurality of LEDs of array 120 may be selected such that LED filament light 105 includes white light and NIR light.

[0058] The LED filament device 200 includes a controller 210 coupled to an array 120 of a plurality of LEDs, where the controller 210 is schematically shown. The controller 210 can be coupled to the array 120 by wire or wirelessly. The controller 210 is configured to individually control the operation of the array 120. The controller 210 can be configured to individually control each of the plurality of LEDs. For example, the controller 210 can turn one or more LEDs on or off, and / or vary the intensity.

[0059] Figure 4An LED filament lamp 300 according to an exemplary embodiment of the present invention is schematically illustrated. The LED filament lamp 300 includes an LED filament 100. The lamp 300 includes the LED filament 100 according to an embodiment of the present invention. The lamp 300 includes a light-transmissive housing 310 that at least partially surrounds the LED filament 100, and a base 320 that includes a cap 325 that is arranged to mechanically and electrically connect the LED filament lamp 300 to a socket of a light fixture.

[0060] Those skilled in the art will recognize that the present invention is by no means limited to the preferred embodiments described above. On the contrary, numerous modifications and variations are possible within the scope of the appended claims. For example, the LED filament 100, the carrier 110, the array 120 of multiple LEDs, etc. may have shapes, dimensions, and / or sizes different from those depicted / described.

Claims

1. A light emitting diode (LED) filament (100), configured to emit LED filament light (105), comprising: carrier (110); An array (120) of a plurality of light emitting diodes (LEDs) is arranged on the carrier; as well as an encapsulant (130) at least partially surrounding the array of the plurality of LEDs and at least partially surrounding the carrier, wherein each LED of the plurality of LEDs is arranged to emit LED light (125), the LED light comprising at least one of: Purple light (121) having a purple main peak wavelength λ1 within a wavelength range of 380 nm to 420 nm, blue light (122) having a blue main peak wavelength λ2 within a wavelength range of 420 nm to 470 nm, cyan light (123) having a cyan main peak wavelength λ3 within a wavelength range of 470 nm to 520 nm, and Red light (124) having a red main peak wavelength λ4 within a wavelength range of 600 nm to 660 nm; wherein the package includes a near-infrared (NIR) phosphor (132) configured to convert at least a portion of the LED light emitted from the plurality of LEDs into NIR converted light (135), the NIR converted light having an NIR main peak wavelength λ5 within a wavelength range of 700 nm to 1400 nm; wherein the LED filament light includes the NIR converted light, wherein the carrier comprises a first major surface (112) and a second major surface (114) opposite the first major surface, and wherein the encapsulant comprises a first encapsulant (134) at least partially surrounding the array of the plurality of LEDs and at least partially covering the first major surface and comprising the NIR phosphor; and The first encapsulant includes a visible light phosphor configured to convert at least a portion of the LED light emitted from the plurality of LEDs into converted visible light, the converted visible light having a main peak wavelength λ6 within a wavelength range of 420 nm to 700 nm, wherein the LED filament light includes the converted visible light.

2. The LED filament of claim 1 , wherein the carrier is light transmissive, wherein the carrier comprises a first major surface ( 112 ) and a second major surface ( 114 ) opposite the first major surface, and wherein the encapsulant comprises a second encapsulant ( 136 ) at least partially covering the second major surface and comprising the NIR phosphor.

3. The LED filament of claim 2 , wherein the encapsulant comprises a first encapsulant ( 134 ) at least partially surrounding the array of the plurality of LEDs and at least partially covering the first major surface, wherein the first encapsulant comprises a light scattering material configured to scatter at least a portion of the LED light emitted from the plurality of LEDs through the carrier. 4 . The LED filament according to claim 1 , wherein the LED filament light comprises at least one of the following: the violet light, the blue light, the cyan light, the red light.

5. The LED filament of any preceding claim, wherein the NIR phosphor is configured to convert 20% to 80% of the LED light emitted from the plurality of LEDs, and wherein the LED filament light includes the NIR converted light and the violet light.

6. The LED filament of any one of claims 1 to 4, wherein the NIR phosphor is configured to convert 20% to 80% of the LED light emitted from the plurality of LEDs, and wherein the LED filament light includes the NIR converted light and the blue light.

7. The LED filament of any one of claims 1 to 4, wherein the NIR phosphor is configured to convert 20% to 80% of the LED light emitted from the plurality of LEDs, and wherein the LED filament light includes the NIR converted light and the cyan light.

8. The LED filament of any one of claims 1 to 4, wherein the NIR phosphor is configured to convert 20% to 80% of the LED light emitted from the plurality of LEDs, and wherein the LED filament light includes the NIR converted light and the red light.

9. The LED filament of any one of the preceding claims, wherein the plurality of LEDs are arranged to emit at least two of the following: the violet light, the blue light, the cyan light, and the red light, and wherein the LED filament light comprises at least one of the following: the violet light, the blue light, the cyan light, and the red light.

10. The LED filament of claim 9, wherein the NIR phosphor is configured to completely convert a first one of the violet light, the blue light, the cyan light, and the red light, and to convert at least a portion of a second one of the violet light, the blue light, the cyan light, and the red light, wherein the second one is different from the first one.

11. The LED filament of any preceding claim, wherein the LED filament light comprises white light having a correlated color temperature (CCT) in the range of 1800K to 6500K and a color rendering index (CRI) of at least 80.

12. An LED filament device (200) comprising the LED filament according to any one of the preceding claims, wherein the plurality of LEDs comprises at least two of the following: at least one purple LED, at least one blue LED, at least one cyan LED, and At least one red LED, The LED filament device comprises a controller (210) configured to individually control at least two of the following: at least one violet LED, at least one blue LED, at least one cyan LED, and at least one red LED.

13. An LED filament lamp (300), comprising: The LED filament according to any one of claims 1 to 11 or the LED filament device according to claim 14, a light-transmitting housing (310) at least partially surrounding the LED filament or the LED filament arrangement, and A base (320), wherein the base includes a cap (325) arranged to mechanically and electrically connect the LED filament lamp to a socket of a lamp fixture.

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