LED filament comprising LED arranged to emit purple light and ultraviolet light

Abstract

A light emitting diode, LED, filament (100) is provided, the LED filament configured to emit LED mercerizing (105). The LED filament comprises a first linear array (110) of a plurality of first light emitting diodes (LEDs), where the plurality of first LEDs are arranged to emit purple light having a wavelength range of 380 nm to 420 nm, and a second linear array (120) of a plurality of second LEDs, where the plurality of second LEDs are arranged to emit ultraviolet (UV) light having a wavelength range of 100 nm to 380 nm, and where the second array is arranged adjacent to and parallel to the first array. The LED filament further includes a first encapsulant (130) at least partially surrounding the first array of the plurality of first LEDs, where the first encapsulant includes a light scattering material configured to scatter violet light emitted from the plurality of first LEDs.

Description

Technical Field

[0001] The present invention relates generally to light emitting diodes, LEDs, filaments. More particularly, the present invention relates to LED filaments arranged to emit a combination of ultraviolet, UV and violet light. Background Art

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

[0003] Due to the advantages of using LEDs, interest in replacing conventional light sources with LEDs in many lighting devices is rapidly increasing. It will be appreciated that this replacement, also known as retrofitting, is appreciated and desired by users who wish to have the appearance of an incandescent light bulb. Light source replacement (retrofitting) is usually performed by removing the conventional light source(s) from the fixture (e.g., lamp holder) of the lighting device and attaching an LED, LED device(s) or LED apparatus(s) to the fixture. One of these concepts is based on an LED filament placed in a light bulb, which is popular because the appearance of this type of lamp is very decorative.

[0004] Furthermore, it is interesting to combine the advantageous properties of LED filaments according to the above for aesthetic and light distribution purposes with the advantageous properties of disinfection (germicidal) lighting. It should be understood that disinfection lighting has become a topic of renewed interest as the need for disinfection increases. For example, UVA (315nm to 400nm) and / or violet light (400nm to 420nm) can be used for disinfection purposes, such as inactivating / killing bacteria.

[0005] It should also be noted that there is a desire to replace older technologies (e.g. mercury-based UV lamps) with UV LED-based solutions. Furthermore, existing arrangements comprising LEDs arranged to emit UV light may suffer from complexity and / or operational issues regarding efficiency characteristics and / or safety.

[0006] It is therefore an object of the present invention to combine the advantageous properties of LEDs for energy efficiency and light distribution purposes with the advantageous properties of disinfecting (bactericidal and / or virucidal) lighting. It is another object of the present invention to overcome at least some of the complexities and / or operational issues regarding current / voltage drive properties, efficiency properties and / or safety. Summary of the invention

[0007] Of interest are LED arrangements that combine the favorable attributes of LEDs in terms of energy efficiency, light distribution purposes and / or aesthetics with the favorable attributes of providing disinfecting (bactericidal and / or virucidal) lighting, while providing efficient and / or safe operation.

[0008] This and other objects are achieved by providing a LED filament having the features of the independent claim. Preferred embodiments are defined in the dependent claims.

[0009] Therefore, according to the present invention, there is provided a light emitting diode (LED) filament, which is configured to emit LED filament light. The LED filament comprises a first linear array of a plurality of first light emitting diodes (LEDs), wherein the plurality of first LEDs are arranged to emit violet light in a wavelength range of 380 nm to 420 nm. The LED filament further comprises a second linear array of a plurality of second LEDs, wherein the plurality of second LEDs are arranged to emit ultraviolet (UV) light in a wavelength range of 100 nm to 380 nm, and wherein the second array is arranged adjacent to and parallel to the first array. The LED filament further comprises a first encapsulant at least partially surrounding the first array of the plurality of first LEDs, wherein the first encapsulant comprises a light scattering material, which is configured to scatter the violet light emitted from the plurality of first LEDs.

[0010] Therefore, the present invention is based on the idea of ​​providing an LED filament, which includes a first LED linear array configured to emit violet light via a light scattering encapsulation, and a second LED linear array configured to emit mainly non-scattered ultraviolet light. The first linear array and the second linear array are arranged adjacent to each other and parallel to each other, so that adjacent and parallel linear emissions of violet and UV light can be achieved respectively. Therefore, an LED filament is provided, which can effectively and safely provide disinfecting UV light while providing visible violet light.

[0011] An advantage of the present invention is that a linear array of multiple LEDs provides two adjacent and parallel line emissions of violet light and UV light, respectively, providing a combination of visible violet light and disinfecting UV light.

[0012] A further advantage of the present invention is that the visible violet light can be decorative and aesthetically pleasing and simultaneously indicate when and where the UV light was emitted.Because UV light can be harmful to humans, the violet light emitted by the plurality of first LEDs provides increased safety.

[0013] The present invention is also advantageous in that the plurality of first LEDs surrounded by the light scattering encapsulant can emit violet light in a scattered manner, thereby providing more efficient and aesthetically pleasing visible light, while the second LEDs are arranged outside the light scattering encapsulant so that no UV light is scattered back into the LED filament. By not scattering back the UV light, the risk of UV light damaging the LED filament is significantly reduced, as the UV light can be harmful to the components of the LED filament.

[0014] A further advantage of the invention is that the linear array of a plurality of LEDs of the LED filament allows for an uncomplicated and convenient circuit, which in turn increases the service life of the LED filament and / or reduces the risk of its failure in operation.

[0015] The advantage of the present invention is that the LED is relatively small, and the LED filament providing UV light can be smaller than conventional UV light. Therefore, the UV LED filament of the present invention can be more convenient and versatile.

[0016] It will be appreciated that the wavelength of the first LED, 380 nm to 420 nm, provides both visible light and at least partially disinfecting light.

[0017] It will also be appreciated that the second LED provides UV light having disinfecting properties.

[0018] It should also be understood that the LED filament of the present invention also includes relatively few components. A relatively small number of components is advantageous because LED filaments are relatively cheap to manufacture. In addition, the relatively small number of components of the LED filament means that it is easier to recycle, especially compared to an apparatus or device including a relatively large number of components, which hinders easy disassembly and / or recycling operations.

[0019] The LED filament configured to emit LED filament light comprises a first linear array of a plurality of first LEDs, wherein the plurality of first LEDs are arranged to emit violet light in a wavelength range of 380nm to 420nm. The LED filament further comprises a second linear array of a plurality of second LEDs, wherein the second LEDs are arranged to emit UV light in a wavelength range of 100nm to 380nm. Thus, the LED filament comprises two linear arrays, wherein each linear array comprises (corresponding) a plurality of LEDs. The plurality of first LEDs may comprise at least 10 LEDs, preferably at least 20 LEDs, more preferably at least 30 LEDs, and most preferably at least 40 LEDs. The plurality of second LEDs may comprise at least 5 LEDs, preferably at least 10 LEDs, more preferably at least 15 LEDs, and most preferably at least 20 LEDs. The second linear array is arranged adjacent to and parallel to the first linear array. For example, the first array and the second array may be arranged linearly adjacent to each other and extend along the LED filament. In addition, the LED filament comprises a first encapsulant at least partially surrounding the first array of first LEDs, wherein the first encapsulant comprises a light scattering material configured to scatter violet light emitted from the first LEDs. The term "encapsulant" herein means a material, element, device, etc., which is configured or arranged to at least partially surround, enclose and / or surround a linear array. The light scattering material is configured to scatter light. More specifically, the light scattering material can be configured to scatter violet light in the wavelength range of 380nm to 420nm. The light scattering material can achieve forward scattering and / or backward scattering. The scattering can be mainly forward scattering or backward scattering. In one embodiment, at least 50% of the violet light emitted from the plurality of first LEDs is scattered by the light scattering material, preferably at least 70%, more preferably at least 80%, and most preferably at least 90%. In another embodiment, at most 10% of the UV light emitted from the plurality of second LEDs is scattered, preferably at most 7%, more preferably at most 5%, and most preferably at most 3%.

[0020] According to an embodiment of the present invention, the LED filament further comprises a second encapsulant, wherein the second encapsulant is transparent and at least partially surrounds a second array of a plurality of second LEDs. The term "transparent" herein means that the second encapsulant comprises a transparent and / or translucent material, composition and / or substance. The second encapsulant may have some light scattering properties. For example, at most 10% of the UV light emitted from the plurality of second LEDs is scattered in the second encapsulant, preferably at most 7%, more preferably at most 5%, and most preferably at most 3%. An advantage of this embodiment is that it can improve the disinfection performance of the LED filament because the UV light can be better extracted from the second LED, for example via better distribution of the light after passing through the second encapsulant.

[0021] According to an embodiment of the present invention, the light scattering material includes a silicone matrix having at least one of Al2O3 particles, BaSO4 particles, TiO2 particles, SiO2 particles, CaF2 particles, CaCO3 particles, and BaTiO3 particles.

[0022] According to an embodiment of the present invention, the first encapsulant is configured to reflect UV light emitted from the plurality of second LEDs. An advantage of this embodiment is that it reduces the amount of UV light that can reach the plurality of first LEDs.

[0023] According to an embodiment of the present invention, the number N1 of the first LEDs and the number N2 of the second LEDs may satisfy N1≥2N2, in particular N1≥3N2, or N1≥4N2. In addition, the number N1 of the first LEDs of the first array per unit length L1 and the number N2 of the second LEDs of the second array per unit length L2 may satisfy N1 / L1≥2N2 / L2, in particular N1 / L1≥3N2 / L2 or N1 / L1≥4N2 / L2. In other words, the number N1 of the first LEDs is equal to or greater than four times the number N2 of the second LEDs, or the number N1 / L1 of the first array per unit length (i.e., the LED density of the first linear array) is equal to or greater than two, three or even four times the number N2 / L2 of the second LEDs of the second array per unit length.

[0024] The advantage of this embodiment is that a more efficient and aesthetically pleasing LED light distribution is provided. This is because by having a relatively high number of LEDs, an improved line emission is achieved for visible violet light, while the number of second LEDs emitting invisible UV light is relatively small, so as to provide more efficient disinfection lighting, for example by generating less heat, while still providing sufficient disinfection lighting.

[0025] According to an embodiment of the present invention, the plurality of first LEDs include a first LED subset, which is arranged to emit violet light having a first main peak wavelength DPW1 in the range of 400nm to 410nm. "Main peak wavelength" here means the centroid wavelength, i.e., the wavelength at which the UV light reaches maximum intensity. An advantage of this embodiment is that the LED light includes a wavelength of UV light that is a balance option between safety and disinfection performance.

[0026] According to an embodiment of the present invention, at least one of the plurality of first LEDs comprises a second LED subset, the second LED subset being arranged to emit violet light having a second main peak wavelength DPW2 in the range of 410nm to 420nm, and the plurality of first LEDs comprises a third LED subset, the third LED subset being arranged to emit violet light having a third main peak wavelength DPW3 ​​in the range of 390nm to 400nm. The advantage of this embodiment is that two violet spectrum intervals are used in combination, for example, different ranges of visible light are provided, thereby providing a more aesthetic effect and / or disinfection performance level. For example, the second subset may be arranged on a portion of the LED filament, while the third subset is arranged on a different portion of the LED filament, so that a user can choose between better disinfection performance and more harmful / less safe light, and limited disinfection performance and more harmless / safer light by moving in the area illuminated by the LED filament light. Light in the wavelength range of 380nm to 400nm has a relatively high disinfection performance compared to light in the wavelength range of 400nm to 420nm. Light with a wavelength range of 400nm to 420nm is more visible and relatively safe compared to light with a wavelength range of 380nm to 400nm. Light with a wavelength range of 400nm to 410nm can provide a balanced / optimal light output in terms of performance, safety, and visibility.

[0027] According to an embodiment of the present invention, the encapsulant comprises an elongated shape and has a length of at least 4 cm, wherein the plurality of first LEDs comprises at least 10 first LEDs, and wherein the distance d between adjacent first LEDs of the first array satisfies d≤4 mm. An advantage of this embodiment is that the first LEDs can emit purple light in an improved line pattern. As a result, the purple light is emitted in a more aesthetically pleasing manner.

[0028] According to an embodiment of the present invention, a plurality of second LEDs are arranged to emit UVC light in a wavelength range of 100 nm to 280 nm. An advantage of this embodiment is that UVC light in the range of 100 nm to 280 nm can penetrate the skin less than longer wavelength UV light (such as UVB light). Therefore, UVC light can be less harmful than other types of UV light, such as to human skin. An additional advantage of this embodiment is that the UVA wavelength range has improved disinfection performance, i.e., improved operation of inactivating / killing bacteria.

[0029] According to an embodiment of the present invention, an LED device is provided. The LED device comprises at least one LED filament according to any one of the preceding claims and a carrier, wherein the at least one LED filament is supported by the carrier. It should be understood that the LED filament can be arranged on and / or supported by a carrier. The term "carrier" here means an element, a substrate, etc. that is arranged to mechanically and / or electrically support the LED. Thus, a plurality of LEDs can be arranged, mounted and / or mechanically coupled to / to a carrier (e.g., a substrate), wherein the carrier is configured to mechanically and / or electrically support the LED. The carrier can also be elongated so as to support an LED array of (elongated) LED filaments.

[0030] According to an embodiment of the invention, the LED device further comprises a control unit, which is configured to (individually) control the plurality of first LEDs and the plurality of second LEDs. The LED device further comprises a user interface, wherein the controller is configured to be controlled by an operator via the user interface. An advantage of this embodiment is that the individual control of the plurality of LEDs provided by the controller may even further improve aesthetics and / or light distribution purposes, with the advantageous properties of disinfecting (bactericidal and / or virucidal) lighting. For example, the controller may thereby be configured to control one or more properties (e.g., intensity) of the LEDs of the first linear array.

[0031] According to an embodiment of the present invention, the LED device further comprises a sensor configured to detect at least one of the presence of at least one person and the distance of the person from the sensor. In the case where the sensor detects the presence of at least one person and / or at least one person is located within a predetermined distance D to the sensor, the control unit is configured to perform a reduction in the intensity of the UV light emitted by the plurality of second LEDs and / or turn off the UV light emitted by the plurality of second LEDs. The sensor may include a motion sensor and / or a proximity / presence sensor. An advantage of this embodiment is that the UV light can be automatically adjusted depending on whether a person is detected. Therefore, the LED device can be operated more safely because the UV light can be weakened and / or turned off in the event that a person is in danger of being irradiated by the UV light. In one embodiment, the turning off of the UV light emitted by the plurality of second LEDs can be based (only) on the (threshold) distance of the person from the sensor. In another embodiment, the reduction in the intensity of the UV light emitted by the plurality of second LEDs can be based (only) on the presence of at least one person detected by the sensor.

[0032] In one embodiment, the LED device includes a control unit and a sensor, the control unit is configured to individually control a plurality of first LEDs and a plurality of second LEDs, and the sensor is configured to detect at least one of the presence of at least one person and the distance of the person from the sensor. In the event that the sensor detects at least one of the presence of the at least one person and the at least one person is within a predetermined distance D from the sensor, the control unit is configured to perform one of reducing the intensity of UV light emitted by the plurality of second LEDs and turning off the UV light emitted by the plurality of second LEDs.

[0033] According to an embodiment of the invention, the control unit is configured to perform one of the following: reduce the intensity of the violet light emitted by the plurality of first LEDs; reduce the intensity of the violet light emitted by the plurality of first LEDs with a time delay relative to at least one of the presence of at least one person being detected and at least one person being within a predetermined distance D to the sensor, and / or turn off the violet light emitted by the plurality of first LEDs with a time delay relative to at least one of the presence of at least one person being detected and at least one person being within a predetermined distance D to the sensor. An advantage of this embodiment is that a time window is created in which violet light is emitted by the plurality of first LEDs and UV light is not emitted by the plurality of second LEDs, making it less likely that a person is inadvertently exposed to UV light that may be harmful. In one embodiment, the time delay may be at least 0.1 seconds, preferably at least 0.5 seconds, more preferably at least 0.8 seconds, and most preferably at least 1 second. In another embodiment, the time delay may be at most 10 seconds, preferably at most 5 seconds, more preferably at most 3 seconds, and most preferably at most 2 seconds.

[0034] According to an embodiment of the present invention, the LED device includes a housing configured to at least partially surround a plurality of first LEDs and a plurality of second LEDs, and wherein the housing is translucent to violet light emitted by the plurality of first LEDs and is translucent to UV light emitted by the plurality of second LEDs.

[0035] According to an embodiment of the present invention, a tubular lighting device is provided, the tubular lighting device comprising an LED device according to an embodiment of the present invention, wherein the housing comprises a first end cap at a first end of the tubular housing; and a second end cap at a second end of the tubular housing, the second end being opposite to the first end of the tubular housing. The first end cap and the second end cap respectively comprise a first pair of pins and a second pair of pins; and a fixture comprising a first connector and a second connector, wherein the first pair of pins and the second pair of pins of the tubular housing are configured to be matched and connected to the first connector and the second connector, respectively, for mechanical and electrical connection between the tubular housing and the fixture.

[0036] Further objectives, 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

[0037] 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.

[0038] Figure 1a-1b schematically illustrates an LED filament according to an exemplary embodiment of the present invention,

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

[0040] Figure 3 Schematically shows an LED device according to an exemplary embodiment of the present invention,

[0041] Figure 4 schematically shows the distribution of violet light and UV light as a function of time according to an exemplary embodiment of the present invention, and

[0042] Figure 5 A tubular LED device according to an exemplary embodiment of the invention is schematically shown. DETAILED DESCRIPTION

[0043] Figure 1a-1b An LED filament 100 according to an exemplary embodiment of the present invention is schematically shown. Each of the LED filaments 100 includes a first linear array 110 of a plurality of first light emitting diodes LED. The plurality of first LEDs are arranged to emit violet light in a wavelength range of 380nm to 420nm. The LED filament 100 includes a second linear array 120 of a plurality of LEDs. The plurality of second LEDs are arranged to emit ultraviolet UV light in a wavelength range of 100nm to 380nm. Alternatively, the plurality of second LEDs may be arranged to emit UVC light in a wavelength range of 100nm to 280nm. In addition, in Figure 1a-1bIn the embodiment, the LED filament 100 includes an elongated shape extending in a first direction A. The first array 110 and the second array 120 extend linearly in a direction parallel to the first direction A. The second array 120 is adjacent to the first array 110 and is arranged in parallel. Therefore, the LED filament 100 emits filament light 105, wherein the filament light 105 includes both violet light and UV light. The LED filament light 105 provides both visible violet light and disinfecting UV light. The plurality of first LEDs and the plurality of second LEDs can emit light simultaneously, so that the violet light of the plurality of first LEDs can indicate when the UV light of the plurality of second LEDs is emitted. The violet light of the plurality of first LEDs and the UV light of the plurality of second LEDs can be emitted at least partially in the same area, and / or at least partially have the same light distribution cone, so that the violet light can indicate the location where the UV light is emitted.

[0044] exist Figure 1a-1b, the number N1 of the first LEDs and the number N2 of the second LEDs satisfy N1≥4N2. In addition, the number N1 of the first LEDs of the first array 110 per unit length L1 and the number N2 of the second LEDs of the second array 120 per unit length L2 satisfy N1 / L1≥4N2 / L2. In other words, if the number of the first LEDs is 4 times higher than the number of the second LEDs, and the LED density of the first array 110, i.e., the number of LEDs per unit length, is 4 times higher than that of the second array 120. It should be understood that the number N1 of the first LEDs may be equal to or greater than four times the number N2 of the second LEDs, and / or the number N1 / L1 of the first LEDs of the first array per unit length (i.e., the LED density of the first linear array) may be equal to or greater than four times the number N2 / L2 of the second LEDs of the second array per unit length. In addition, it should be understood that the number of LEDs of each array per unit length may vary, and the LED density may also vary. The LED filament 100 includes a first encapsulant 130, wherein the first encapsulant 130 at least partially surrounds the first array 110 of a plurality of first LEDs. It should be understood that the first encapsulant 130 may surround some or all of the plurality of first LEDs. In addition, it should be understood that the first encapsulant 130 may completely surround some or all of the plurality of first LEDs. The first encapsulant 130 may include a light scattering material. The light scattering material may include a silicone matrix having at least one of Al2O3 particles, BaSO4 particles, TiO2 particles, SiO2 particles, CaF2 particles, CaCO3 particles, and BaTiO3 particles. In addition, the first encapsulant 130 may be configured to reflect UV light emitted from the plurality of second LEDs. For example, the first encapsulant 130 may include a material that reflects UV light in a wavelength range of 100nm to 380nm. The first encapsulant 130 may include an elongated shape. The first encapsulant 130 may preferably have a length of at least 4cm, and the plurality of first LEDs may preferably include at least 10 first LEDs, wherein the distance d between adjacent first LEDs of the first array 110 preferably satisfies d≤4mm. It should be understood that the length of the LED filament 100 and / or the first array 110 and / or the second array 120 may be longer than 4 cm and still achieve the line emission effect of purple light.

[0045] Figure 1bAn LED filament 100 according to an exemplary embodiment of the present invention is schematically shown. The plurality of first LEDs of the first array 110 include a first LED subset 110a, which is arranged to emit violet light having a first main peak wavelength DPW1 in the range of 400nm to 410nm. The plurality of first LEDs of the first array 110 also include a second LED subset 110b, which is arranged to emit violet light having a second main peak wavelength DPW2 in the range of 410nm to 420nm. The plurality of first LEDs of the first array 110 also include a third LED subset 110c, which is arranged to emit violet light having a third main peak wavelength DPW3 ​​in the range of 390nm to 400nm. It should be understood that the plurality of first LEDs may include any combination of the first LED subset, the second LED subset, and the third LED subset.

[0046] Figure 2 Schematically shows an LED device 200 according to an exemplary embodiment of the present invention. The LED device 200 includes at least one LED filament 100, which is configured to emit LED filament light 105. It should be noted that the LED filament 100 is an exemplary embodiment of the present invention and has the same Figure 1a-1b The LED filaments 100 shown in FIG. 1 share several features common to the LED filaments 100 and are referred to herein. Figure 1a-1b and related text to increase understanding of at least some features and / or functions of the LED filament 100. As shown in the first direction A, for ease of understanding, Figure 2 At least one LED filament is perpendicular to the LED filament 100 shown in FIG. 1 . The LED device 200 includes a carrier 140. The LED filament 100 is supported / carried by the carrier 140. The LED filament 100 may be arranged on the carrier 140. Figure 2 In the embodiment, the LED filament 100 includes a first linear array 110 of a plurality of first LEDs and a second linear array 120 of a plurality of second LEDs. The first linear array 110 and the second linear array 120 are arranged adjacent to and in parallel.

[0047] Figure 2The LED filament 100 of the LED device 200 in the embodiment of the present invention includes a first encapsulant 130 that at least partially surrounds the first array 110. The first encapsulant 130 includes a light scattering material that is configured to scatter violet light from the plurality of first LEDs. The first encapsulant 130 may also be configured to reflect UV light emitted by the plurality of second LEDs. For example, the first encapsulant 130 may include a material that reflects UV light of the plurality of second LEDs. The LED filament 100 also includes a second encapsulant 190 that at least partially surrounds the second array 120. It should be understood that the second encapsulant 190 may surround some or all of the plurality of second LEDs. Furthermore, it should be understood that the second encapsulant 190 may completely surround some or all of the plurality of second LEDs. The second encapsulant 190 is configured to be transparent. For example, the second encapsulant 190 includes a transparent material. The second encapsulant 190 may be configured to at least partially direct UV light so that the distribution of the UV light may be improved, for example, allowing for improved sterilization. The LED device 200 includes a housing 170 configured to at least partially surround a plurality of first LEDs and a plurality of second LEDs. The housing 170 is transparent to violet light emitted by the plurality of first LEDs and is transparent to UV light emitted by the plurality of second LEDs. The housing 170 may include an elongated semi-cylindrical shape extending along the LED filament 100. The housing 170 may be attached / mounted / fixed to the carrier 140. The housing 170 may at least partially surround the LED filament 100 between the carrier 140 and the housing 170.

[0048] The LED filament light 105 includes a combination of light from a first plurality of LEDs and a second plurality of LEDs. A portion of the LED filament light 105 is visible light in a wavelength range of 380 nm to 420 nm, and a second portion is invisible UV light in a wavelength range of 100 nm to 380 nm. The combination of violet light and UV light provides visible light emission of violet light, and / or close to UV light that can disinfect. The visible violet light of the first plurality of LEDs can be used as a visual guide to observe what is being illuminated by the UV light. The violet light of the first plurality of LEDs can be at least partially disinfecting light.

[0049] Figure 3 Schematically shows an LED device 200 according to an exemplary embodiment of the present invention. It should be noted that Figure 3 The LED device 200 shown in FIG. Figure 2 The LED devices 200 shown in FIG. 1 and 2 share several features in common, and are therefore referenced to Figure 21 and associated text to increase understanding of some of the features and / or functions of the LED device 200. The LED device 200 includes an LED filament 100. The LED filament 100 includes a first array 110 and a second array 120 of LEDs, and a first encapsulant 130 at least partially surrounding the first array 110. The first array 110 and the second array 120 are supported / arranged on a carrier 140. The LED device 200 includes a housing 170 at least partially surrounding the first array 110 and the second array 120.

[0050] exist Figure 3 , the LED device further comprises a control unit 150, which is configured to individually control the plurality of first LEDs and the plurality of second LEDs. The LED device 200 further comprises a user interface 180, wherein the control unit 150 is configured to be controlled by an operator via the user interface 180. The control unit 150 may form part of the LED device and / or may be arranged outside the LED device. The LED device 200 further comprises a sensor 160 (shown schematically). The sensor 160 may form part of the LED device and / or may be arranged outside the LED device. The sensor 160 is configured to detect the presence of at least one person and / or the distance of the person 165 to the sensor 160. In the event that the sensor 160 detects the presence of (one or more) persons 165 and / or (one or more) persons 165 are located within a predetermined distance D to the sensor 160, the control unit 150 is configured to reduce the intensity of the UV light emitted by the plurality of second LEDs and / or turn off the UV light emitted by the plurality of second LEDs. The control unit 150 is also configured to reduce the intensity of the violet light emitted by the plurality of first LEDs and / or turn off the violet light emitted by the plurality of first LEDs. The reduction in intensity and / or shut down may be performed with a time delay relative to the detection of the presence of person(s) 165 and / or the location of person(s) 165 within a predetermined distance D from the sensor 160 .

[0051] Figure 4 Schematically shows the distribution of violet light represented by a first series S1 provided by a plurality of first LEDs and UV light represented by a second series S2 provided by a plurality of second LEDs, their respective intensities (y-axis, arbitrary units) as a function of time (x-axis, arbitrary units). Figure 4 In the embodiment, the purple light S1 gradually decreases after a time T1, wherein T1 is the time when the sensor detects that the person and / or at least one person is located within a predetermined distance D from the sensor. The control unit may be configured to control the intensity of the plurality of first LEDs such that the intensity decreases over time. Figure 3Examples of sensors and control units used are depicted and described in and related texts. The purple light S1 is reduced until time T2, when the plurality of first LEDs are turned off and / or the intensity of the purple light reaches zero or a relatively low value. The reduction of the purple light S1 can be linear and / or non-linear. After time T1, the ultraviolet light S2 can be turned off directly / quickly / instantly. The control unit can be configured to control the plurality of second LEDs so that they are turned off. It should be understood that time T2 occurs after time T1. Therefore, the plurality of second LEDs are turned off before the plurality of first LEDs. The delay T2-T1 between the turn-off time of the plurality of second LEDs and the plurality of first LEDs can be in the range of 0.1 seconds to 6 seconds.

[0052] Figure 5 A tubular LED device TLED 300 according to an exemplary embodiment of the present invention is schematically shown. The TLED 300 includes a housing 170. According to an embodiment of the present invention, the housing 170 at least partially surrounds an LED filament (not shown). Therefore, the housing 170 at least partially surrounds a plurality of first LEDs and a plurality of second LEDs. It should be understood that the housing 170 can completely surround the plurality of first LEDs and the plurality of second LEDs, and / or the entire LED filament 100. The housing 170 is transparent to both the purple light transmitted by the plurality of first LEDs and the UV light emitted by the plurality of second LEDs. The housing 170 includes a first end cap 310 at a first end of the housing 170. The housing 170 is a tubular housing elongated in the length direction of the TLED. The tubular housing 170 includes a second end cap 315 at a second end of the tubular housing 170, the second end being opposite to the first end of the tubular housing 170. The first end cap 310 and the second end cap 315 include a first pair of pins 320a and a second pair of pins 320b, respectively. The TLED 300 also includes a fixing member 340. The fixture 340 includes a first connector 345a and a second connector 345b. The first pair of pins 320a and the second pair of pins 320b are configured to be mated and connected to the first connector 345a and the second connector 345b, respectively, for mechanical and electrical connection between the tubular housing 170 and the fixture 140.

Claims

1. A light emitting diode (LED) filament (100), configured to emit LED filament light (105), comprising a first linear array (110) of a plurality of first light emitting diodes (LEDs), wherein the plurality of first LEDs are arranged to emit violet light in a wavelength range of 380 nm to 420 nm, a second linear array (120) of a plurality of second LEDs, wherein the plurality of second LEDs are arranged to emit ultraviolet (UV) light in a wavelength range of 100 nm to 380 nm, and wherein the second array is arranged adjacent to and parallel to the first array, a first encapsulant (130) at least partially surrounding the first array of the plurality of first LEDs, wherein the first encapsulant includes a light scattering material configured to scatter the violet light emitted from the plurality of first LEDs, and The number N1 of the first LEDs and the number N2 of the second LEDs satisfy N1≥2N2, in particular N1≥3N2, or N1≥4N2, and the number N1 of the first LEDs of the first array per unit length L1 and the number N2 of the second LEDs of the second array per unit length L2 satisfy N1 / L1≥2N2 / L2, in particular N1 / L1≥3N2 / L2 or N1 / L1≥4N2 / L2.

2. The LED filament of claim 1, further comprising a second encapsulant (190), wherein the second encapsulant is transparent and at least partially surrounds the second array of the plurality of second LEDs.

3. The LED filament according to claim 1 or 2, wherein the light scattering material comprises a silicone matrix having at least one of Al2O3 particles, BaSO4 particles, TiO2 particles, SiO2 particles, CaF2 particles, CaCO3 particles and BaTiO3 particles.

4. The LED filament of any one of the preceding claims, wherein the first encapsulant is configured to reflect at least a portion of the UV light emitted from the plurality of second LEDs.

5. The LED filament according to any one of the preceding claims, wherein the plurality of first LEDs comprises a first subset of LEDs (110a) arranged to emit violet light having a first dominant peak wavelength DPW1 in the range of 400 nm to 410 nm.

6. The LED filament according to any one of the preceding claims, wherein at least one of the following is satisfied: The plurality of first LEDs include a second LED subset (110b) arranged to emit violet light having a second dominant peak wavelength DPW2 in the range of 410 nm to 420 nm, and The plurality of first LEDs includes a third LED subset (110c) arranged to emit violet light having a third dominant peak wavelength DPW3 ​​in the range of 380 nm to 400 nm.

7. The LED filament according to any one of the preceding claims, wherein the encapsulant comprises an elongated shape and has a length of at least 4 cm, and wherein the plurality of first LEDs comprises at least 10 first LEDs, and wherein a distance d between adjacent first LEDs of the first array satisfies d≤4 mm.

8. The LED filament according to any one of the preceding claims, wherein the plurality of second LEDs are arranged to emit UVC light in a wavelength range of 100 nm to 280 nm.

9. A light emitting diode (LED) device (200), comprising at least one LED filament according to any one of the preceding claims, and A carrier (140), wherein the at least one LED filament is supported by the carrier.

10. The LED device according to claim 9, further comprising a control unit (150) configured to individually control the plurality of first LEDs and the plurality of second LEDs, and A user interface (180), wherein the control unit is configured to be controlled by an operator via the user interface.

11. The LED device according to claim 10, further comprising a sensor (160) configured to detect at least one of the presence of at least one person (165) and the distance of the person from the sensor, and In case the sensor detects at least one of the presence of at least one person and at least one person is located within a predetermined distance D from the sensor, the control unit is configured to perform one of the following: reducing the intensity of the UV light emitted by the plurality of second LEDs, and The UV light emitted by the plurality of second LEDs is turned off.

12. The LED device according to claim 11, wherein the control unit is configured to perform one of the following: reducing the intensity of the purple light emitted by the plurality of first LEDs, reducing the intensity of the purple light emitted by the plurality of first LEDs with a time delay relative to at least one of detecting the presence of at least one person and at least one person being within a predetermined distance D from the sensor, and The purple light emitted by the plurality of first LEDs is turned off with a time delay relative to at least one of detecting the presence of at least one person and at least one person being located within a predetermined distance D from the sensor.

13. An LED device according to any one of claims 9 to 12, wherein the LED device includes a housing (170), the housing being configured to at least partially surround the plurality of first LEDs and the plurality of second LEDs, and wherein the housing is translucent to the purple light emitted by the plurality of first LEDs, and is translucent to the UV light emitted by the plurality of second LEDs.

14. A tubular lighting device (300), comprising The LED device according to claim 13, The housing comprises a first end cap (310) at a first end of the tubular housing, and a second end cap (315) at a second end of the tubular housing, the second end being opposite to the first end of the tubular housing, The first end cover and the second end cover respectively include a first pair of pins (320a) and a second pair of pins (320b), A fixture (340) comprises a first connector (345a) and a second connector (345b), wherein the first pair of pins and the second pair of pins of the tubular housing are configured to be mated and connected to the first connector and the second connector, respectively, for mechanical and electrical connection between the tubular housing and the fixture.

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