LED filament arrangement comprising one or more LED filaments

Abstract

There is provided a LED filament arrangement (100) comprising a set (120) of LED filament(s) (130a-d). The set comprises a first LED filament section (150) comprising a first elongated carrier section (170), a plurality of first LED chips (180) arranged on the first elongated carrier section, and a first elongated encapsulant (210). The set further comprises a second LED filament section (230) comprising a second elongated carrier section (250), electrically conductive tracks (260) arranged on the second elongated carrier section, and a plurality of LED packages (280) electrically connected to the electrically conductive tracks. Each LED package comprises a package carrier (290), a second LED chip (300) arranged on the package carrier, and a package encapsulant (320).

Description

[0001] 2024PF80347

[0002] 1

[0003] LED FILAMENT ARRANGEMENT COMPRISING ONE OR MORE LED FILAMENTS

[0004] FIELD OF THE INVENTION

[0005] The present invention generally relates to a light emitting diode, LED, filament arrangement. More specifically, the present invention relates to a LED filament arrangement comprising a set of one or more LED filaments.

[0006] BACKGROUND OF THE INVENTION

[0007] The use of light emitting diodes, LEDs, for illumination purposes continues to attract attention. Compared to incandescent lamps, fluorescent lamps, neon tube lamps, etc., LEDs provide numerous advantages such as a longer operational life, a reduced power consumption, and an increased efficiency related to the ratio between light energy and heat energy.

[0008] Due to the advantageous aspects of the use of LEDs, the interest has rapidly increased to replace conventional light sources with LEDs in many lighting arrangements. It will be appreciated that this replacement, also called retrofitting, is appreciated and desired by users who wish to have the look of an incandescent bulb. The light source replacement (retrofitting) is often performed by removing the conventional light source(s) from the luminaire (e.g. a lamp holder) of the lighting arrangement and attaching the LEDs, LED arrangement(s) or LED device(s) into the luminaire. One of these concepts is based on LED filaments which are placed in a bulb. The visible LED filament(s) may provide a light distribution which is effective and decorative at the same time, whilst taking advantage of LED technology.

[0009] It is of particular interest to even further improve the performance, functionality and / or appearance of LED filament arrangements, lamps or luminaires. More specifically, it is desirable to improve the performance and / or functionality of the light emission and / or light distribution from the LED filament arrangements. Another purpose is to augment the appearance and / or the decorative aspect of the LED filaments and / or the LED filament arrangements, both during operation (on-state) as well as when switched off (off- state). 2024PF80347

[0010] 2

[0011] In EP 4272266 a LED filament is disclosed, comprising a plurality of LEDs wherein the LED filament comprises a center axis, A, and elongates in a meandering shape in a first plane, P, wherein a first portion of the LED filament, which elongates along the center axis, A, comprises an array of the plurality of LEDs and an encapsulant at least partially enclosing the array of the plurality of LEDs, and a second portion of the LED filament, which elongates along the center axis, A, comprises a distribution of LEDs of the plurality of LEDs, and wherein the first portion and the second portion of the LED filament are arranged on opposite sides with respect to the first plane, P.

[0012] SUMMARY OF THE INVENTION

[0013] It is of interest to explore the possibility of combining one or more of the numerous advantages of LED filaments comprising LEDs, whilst improving the LED filaments’ performance and / or functionality, via the properties of the light emission and / or distribution from the LED filaments and improving the appearance and / or the decorative aspect of the LED filaments and / or the LED filament lamps during on-state and off-state.

[0014] This and other objects are achieved by providing a LED filament arrangement having the features in the independent claim. Preferred embodiments are defined in the dependent claims.

[0015] According to the present invention, there is provided a light emitting diode, LED, filament arrangement configured to provide, in an on-state, LED filament arrangement light. The LED filament arrangement comprises a set of at least one LED filament configured to provide, during operation, LED filament light. The set of the at least one LED filament comprises a first LED filament section configured to provide first LED filament section light. The first LED filament section comprises a first elongated carrier section, a plurality of first LED chips arranged on a first major surface of the first elongated carrier section, wherein the plurality of first LED chips is configured to emit first LED chip light, and a first elongated encapsulant at least partially covering the first major surface of the first elongated carrier section and at least partially enclosing the plurality of first LED chips, wherein the first elongated encapsulant comprises a first luminescent material configured to at least partly convert the emitted first LED chip light into first converted light. The set of the at least one LED filament further comprises a second LED filament section configured to provide second LED filament section light. The second LED filament section comprises a second elongated carrier section, electrically conductive tracks arranged on a first major surface of the second elongated carrier section, and a plurality of LED packages electrically connected to the 2024PF80347

[0016] 3 electrically conductive tracks. Each LED package of the plurality of LED packages comprises a package carrier, a second LED chip arranged on the package carrier, wherein the second LED chip is configured to emit second LED chip light, and a package encapsulant at least partly covering the second LED chip, wherein the package encapsulant comprises a second luminescent material configured to at least partly convert the emitted second LED chip light into second converted light.

[0017] Thus, the present invention is based on the idea of providing a LED filament arrangement comprising a combination of a first and a second LED filament section, wherein the first LED filament section comprises a plurality of first LED chips, and the second LED filament section comprises a plurality of LED packages with second LED chips. By the combination of these two kinds of LED technologies, representing (or corresponding to) chip on board (CoB) and surface mount diode (SMD) technologies, this hybrid architecture of the LED filament arrangement provides the benefits of the respective technology concerning e.g. performance and / or functionality (such as light distribution, reliability, cost-efficiency, etc.), appearance, aesthetical attractiveness, etc.

[0018] The present invention is advantageous in that the first LED filament section of the LED filament arrangement, whose architecture represents and / or corresponds to CoB, provides an increased luminous efficiency. The first LED filament section, comprising the plurality of first LED chips, may provide a strong total illumination by its intensity and light concentrated in smaller surface areas of emission.

[0019] The present invention is further advantageous in that the second LED filament section of the LED filament arrangement, whose architecture represents and / or corresponds to SMD, provides a low-power usage and low heat generation. The second LED filament section, comprising the plurality of LED packages with second LED chips, may hereby provide greater brightness with less power compared to other diode options. Hence, the present invention mitigates performance degradation and leads to an improvement of the thermal heat management of the LED filament arrangement.

[0020] The present invention is further advantageous in that the properties of the first elongated encapsulant and the package encapsulant improve the performance and functionality of the LED filament(s) of the LED filament arrangement concerning its light distribution, as well as the appearance and the decorative aspect thereof.

[0021] The present invention is further advantageous in that the properties of the first and second LED filament sections of the set of LED filament(s) may be easily and conveniently customized for desired properties of the light distribution from the LED 2024PF80347

[0022] 4 filament arrangement, as well as the aesthetic appearance of the LED filament arrangement. More specifically, properties of the LED filament(s) and / or the LED filament arrangement such as e.g. flexibility, dimensions (e.g. length, width and / or thickness), LED size and / or distance between LEDs, the type, reflectivity, dimension, etc., of the carrier, may be set, tuned and / or optimized for different purposes. For example, the properties of the first and / or second LED filament sections of the set of LED filament(s) of the LED filament arrangement may be optimized to provide e.g. reliability, cost-efficiency, light distribution, light quality and / or cooling. Furthermore, the properties of the first and second LED filament sections of the set of LED filament(s) of the LED filament arrangement may be set, tuned and / or optimized to provide and / or maintain an aesthetically attractive LED filament (arrangement) look.

[0023] The present invention is further advantageous in that the numerous advantages of using LED technology may be combined with the attractiveness and the appealing properties of the LED filament arrangement as disclosed.

[0024] The present invention is further advantageous in that the LED filament arrangement of the present invention comprises relatively few components. The low number of components is advantageous in that the LED filament arrangement is relatively inexpensive to fabricate. Moreover, the low number of components of the LED filament arrangement implies an easier recycling, especially compared to devices or arrangements comprising a relatively high number of components which impede an easy disassembling and / or recycling operation.

[0025] There is provided a light emitting diode, LED, filament arrangement, configured to provide, in an on-state, LED filament arrangement light. In embodiments, the LED filament arrangement light may be white light having a correlated color temperature, CCT, in a range from 2000 to 6500 K, and preferably a color rendering index, CRI, of at least 80, or at least 85. The LED filament arrangement comprises at set of at least one LED filament. Hence, the set may comprise one (single) LED filament, or a plurality (i.e. two or more) LED filaments. The LED filament(s) is (are) configured to provide, during operation, LED filament light. Preferably, each LED filament has a length, LF, and a width, WF, wherein LF > 5WF or even LF > 10WF. For example, each LED filament may extend along a length axis, LX. The LED filament(s) may be arranged in a straight configuration or in a non-straight configuration such as for example a curved configuration, a 2D / 3D spiral or a helix. The LED filament(s) has (have) a light-emitting surface that extends along the length, 2024PF80347

[0026] 5 and preferably at least partly around the axis of elongation. The light-emitting surface is preferably arranged to homogenously emit light and / or to emit light omnidirectionally.

[0027] The set of the at least one LED filament comprises a first LED filament section configured to provide first LED filament section light. By “section”, it is here meant a part or portion of the LED filament(s). The first LED filament section comprises a first elongated carrier section. The first elongated carrier section may, for instance, be a substrate, that may be rigid (made from e.g. a polymer, glass, quartz, metal or sapphire) or flexible (e.g. made of a polymer or metal e.g. a film or foil). The first elongated carrier section may be reflective or light transmissive, such as translucent and preferably transparent. The first LED filament section comprises a plurality of first LED chips. The first LED chips may be (or correspond to) CoB LEDs. The first LED chips are arranged on a first major surface of the first elongated carrier section, wherein the plurality of first LED chips is configured to emit first LED chip light. Alternatively, the first LED chips may be arranged in the first elongated carrier section.

[0028] The emitted first LED chip light may be white LED light. The plurality of first LED chips may be arranged on the first major surface of the first elongated carrier section in a linear array. By the term “array”, it is here meant a linear arrangement or chain of first LED chips, or the like. The first LED filament section may be provided as a (first) LED strip.

[0029] Each first LED filament section further comprises a first elongated encapsulant at least partially covering the first major surface of the first elongated carrier section and at least partially enclosing the plurality of first LED chips, wherein the first elongated encapsulant comprises a first luminescent material configured to at least partly convert the emitted first LED chip light into first converted light. By the term “encapsulant”, it is here meant an elongated material, element, arrangement, or the like, which in the present context is configured or arranged to at least partially cover, surround, encapsulate and / or enclose the first major surface of the first elongated carrier section and the plurality of first LED chips. The encapsulant may be a polymer material which may be flexible such as for example a silicone. The luminescent material of the first elongated encapsulant may be a phosphor such as an inorganic phosphor and / or quantum dots or rods.

[0030] The second LED filament section is configured to provide second LED filament section light. The second LED filament section comprises a second elongated carrier section. It should be noted that the second elongated carrier section may have one of more properties and / or features in common with the first elongated carrier section. The second LED filament section further comprises electrically conductive tracks arranged on a first 2024PF80347

[0031] 6 major surface of the second elongated carrier section. The second LED filament section further comprises a plurality of LED packages electrically connected to the electrically conductive tracks. Each LED package of the plurality of LED packages comprises a package carrier. It should be noted that the package carrier may have one of more properties and / or features in common with the first and / or second elongated carrier section(s). Each LED package further comprises a second LED chip arranged on the package carrier. Hence, the package carrier carries / supports the second LED chip. Alternatively, the second LED chip may be arranged in the package carrier. The second LED chip is configured to emit second LED chip light. The emitted second LED chip light may be white LED light. The LED package may be (or correspond to) SMD LED technology or architecture. Each LED package further comprises a package encapsulant at least partly covering the second LED chip. The package encapsulant comprises a second luminescent material configured to at least partly convert the emitted second LED chip light into second converted light. It should be noted that the package encapsulant and the first elongated encapsulant may have one or more features and / or properties in common (e.g. the luminescent material). Alternatively, the package encapsulant and the first elongated encapsulant may be different encapsulants concerning features such as size, material, etc. The second LED filament section may be provided as a (second) LED strip.

[0032] According to an embodiment of the present invention, the set of at least one LED filament may comprise at least one first LED filament comprising the first LED filament section, and at least one second LED filament comprising the second LED filament section. Hence, the set of LED filament(s) may comprise one or more first LED filaments (each) comprising the first LED filament section, and one or more second LED filaments (each) comprising the second LED filament section. Phrased differently, at least two different LED filaments (i.e. first and second LED filaments) may be provided comprising a respective first and second LED filament section). The present embodiment is advantageous in that the distribution of the first and second LED filament sections on different LED filaments may even further contribute to the beneficial performance, lighting distribution and / or attractiveness of the LED filament arrangement.

[0033] According to an embodiment of the present invention, the set of at least one LED filament may comprise at least one third LED filament comprising the first LED filament section and the second LED filament section. Hence, the third LED filament(s) may comprise both the first LED filament section and the second LED filament section. By the arrangement of the first and second LED filament sections on a single (third) LED filament 2024PF80347

[0034] 7 of the LED filament arrangement, the present embodiment is advantageous in that a relatively slim and / or cost-efficient LED filament arrangement may be provided whilst achieving an optimized performance and / or functionality of its light emission and / or light distribution as well as augmenting the appearance and / or the decorative aspect of the LED filament(s) and / or LED filament arrangement. Hence, the LED filament arrangement may hereby conveniently and efficiently provide the benefits of the combination of the CoB and SMD technology on a single LED filament (although it should be noted that the LED filament arrangement may comprise a plurality of these (third) LED filaments each comprising a first and second LED filament section.

[0035] According to an embodiment of the present invention, one of the first LED filament section and the second LED filament section are colinearly arranged, and the first LED filament section and the second LED filament section are arranged in parallel and adjacent to each other, is fulfilled. Hence, the first and second LED filament sections may be colinearly arranged (i.e. arranged in sequence one after the other) or be arranged in parallel and adjacent to each other (either on a (single) LED filament or on two or more LED filaments). It should be noted that the present invention encompasses an arrangement of first and second LED filament sections on a single LED filament of the set of LED filament(s) as well as an arrangement of first and second LED filament sections on respective LED filaments of the set of LED filament(s). The colinear arrangement of the first and second LED filament sections of the present embodiment is advantageous in that the plurality of first and second LED chips may be provided as a (single) linear array of LEDs, which may even further improve the desired light distribution and / or aesthetical appearance of the LED filament arrangement. The colinear arrangement of the first and second LED filament sections of the present embodiment is further advantageous in that the dimension(s) of the LED filament arrangement may be reduced, e.g. leading to a slimmer LED filament arrangement. The (alternative) arrangement of the first and second LED filament sections in parallel and adjacent to each other (arranged on a (single) LED filament or on two or more LED filaments) of the present embodiment is advantageous in that a particularly desirable light distribution and / or decorative appearance of the LED filament(s) and / or LED filament arrangement may be obtained.

[0036] According to an embodiment of the present invention, the plurality of first LED chips may be adherently fastened to the first elongated carrier section. For example, the plurality of first LED chips may be glued on the first elongated carrier section. The present 2024PF80347

[0037] 8 embodiment is advantageous in that a convenient and / or cost-efficient LED filament arrangement may be provided and / or produced.

[0038] According to an embodiment of the present invention, each LED package of the plurality of LED packages is soldered to the electrical tracks. The present embodiment is advantageous in that the soldering provides a convenient and / or cost-efficient LED filament arrangement, as well as the production thereof.

[0039] According to an embodiment of the present invention, the first LED filament section may be a chip on board, CoB, and / or each LED package of the plurality of LED packages may be a surface mounted device LED, SMD. The present embodiment is advantageous in that the combination of the CoB and SMD technologies achieves a particularly beneficial hybrid architecture of the LED filament arrangement. More specifically, the LED filaments’ performance and / or functionality, via the properties of the light emission and / or distribution from the LED filaments, and the appearance and / or the decorative aspect of the LED filaments during on-state and off-state, are enhanced.

[0040] According to an embodiment of the present invention, each LED package of the plurality of LED packages may comprise a reflective cup. By the term “reflective cup”, it is here meant a structure, frame, or the like, which is arranged or configured to at least partially reflect the second converted light. The reflective cup may partially enclose the second LED chip and the package encapsulant. The present embodiment is advantageous in that desired emission of the LED filament arrangement light may be even further ameliorated.

[0041] According to an embodiment of the present invention, the first LED filament section may be free from a reflective cup.

[0042] According to an embodiment of the present invention, the package encapsulant is not in physical contact with the second elongated carrier section.

[0043] According to an embodiment of the present invention, the package encapsulant is not covering (a first major surface) of the second elongated carrier section.

[0044] According to an embodiment of the present invention, the first and second elongated carriers sections may differ in at least one of thickness, T, width, W, and thermal conductivity, KTC. Hence, one or more of the thickness, T, width, W, and thermal conductivity, KTC, of the first and second elongated carriers sections may differ. It should be noted that the first and second elongated carriers sections may differ in further properties such as e.g. type, reflectivity, dimension, etc. The present embodiment is advantageous in that the first and / or second elongated carriers sections may be customized in order to attain desired properties of the LED filament arrangement and / or LED filament arrangement light. 2024PF80347

[0045] 9

[0046] According to an embodiment of the present invention, the thickness of the second elongated carrier may be higher than the thickness of the first elongated carrier.

[0047] According to an embodiment of the present invention, the width of the second elongated carrier may be higher than the width of the first elongated carrier.

[0048] According to an embodiment of the present invention, the thermal conductivity of the second elongated carrier may be higher than the thermal conductivity of the first elongated carrier.

[0049] According to an embodiment of the present invention, a distance, dl, between adjacently arranged first LED chips of the plurality of LED chips, and a distance, d2, between adjacently arranged second LED chips of the plurality of LED packages, fulfil dl < d2, e.g. di < 0.8-d2 or e.g. di < 0.6-d2. Hence, the distance, d2, (pitch) between second LED chips arranged adjacent each other may be larger than the distance, dl, (pitch) between first LED chips arranged adjacent each other. The present embodiment is advantageous in that a particular light distribution effect and / or aesthetical effect may be achieved.

[0050] According to an embodiment of the present invention, the first and second LED filament section lights are emitted in different directions e.g. opposite directions. Hence, the first LED filament section light may be emitted in a first direction, and the second LED filament section light may be emitted in a second direction, wherein the first direction is different from the second direction. The present embodiment is advantageous in that the LED filament arrangement light may be particularly customized (e.g. concerning lighting distribution) and / or concerning its aesthetical attractiveness. For example, the first LED filament section light resulting from the CoB technology may emitted in a first direction, whereas the second LED filament section light resulting from the SMD technology may emitted in a different, second direction.

[0051] According to an example of the present invention, the first LED filament section light may comprise (i) first converted light or (ii) first converted light and part of the first LED chip light.

[0052] According to an example of the present invention, the second LED filament section light may comprise (i) second converted light or (ii) second converted light and part of the second LED chip light.

[0053] According to an example of the present invention, the LED filament arrangement light may be white light having a correlated color temperature in a range from 1800K to 6500K and optionally a color rendering index of at least 80 or at least 85. 2024PF80347

[0054] 10

[0055] According to an example of the present invention, the first LED chip light may be blue light and / or the second LED chip light may be blue light.

[0056] According to an example of the present invention, the first luminescent material may comprises a first green-yellow phosphor and / or a first red phosphor.

[0057] According to an example of the present invention, the second luminescent material may comprises a second green-yellow phosphor and / or a second red phosphor.

[0058] According to an example of the present invention, the second LED filament section light may have a different beam angle (i.e. full-width-half-max) e.g. smaller than the first LED filament section light.

[0059] According to an example of the present invention, each LED package of the plurality of LED packages may comprise one or more cathode contacts and one or more anode contacts.

[0060] According to an example of the present invention, each package encapsulant may be arranged in a reflective cup.

[0061] According to an example of the present invention, each second LED chip may be larger (e.g. in epitaxial surface area) than the first LED chip.

[0062] According to an embodiment of the present invention, the first LED filament section light may have a first correlated color temperature, CCT1, and the second LED filament section light may have a second correlated color temperature, CCT2, wherein |CCT1 - CCT2| < 300 K. Hence, the difference between the first correlated color temperature, CCT1, of the first LED filament section light and the second correlated color temperature, CCT2, of the second LED filament section light, may be relatively small. Phrased differently, and according to an example, the first correlated color temperature, CCT1, of the first LED filament section light and the second correlated color temperature, CCT2, of the second LED filament section light may be similar, or substantially the same. Alternatively, |CCT1 - CCT2| may be > 300 K.

[0063] According to an embodiment of the present invention, the LED filament arrangement further comprises a plurality of first LED filament sections, and a first circuitry connecting the LED filament sections of the plurality of first LED filament sections and / or a plurality of second LED filament sections, and a second circuitry connecting the LED filament sections of the plurality of second LED filament sections. Hence, the plurality of first and second LED filament sections may each comprise a respective first and second circuitry. 2024PF80347

[0064] 11

[0065] According to an embodiment of the present invention, the LED filament arrangement may further comprise a controller coupled to the set of at least one LED filament, wherein the controller is configured to individually control each LED filament of the set of at least one LED filament. By “controller”, it is here meant any device, unit, or the like, which is able to control the luminous flux either by wire or via wireless technology. The present example is advantageous in that the controller may conveniently and efficiently control the LED filament(s) of the set of LED filament(s), thereby even further ameliorating the light emission from the LED filament(s) and improving the appearance and / or the decorative aspect of the LED filament(s).

[0066] According to an embodiment of the present invention, the LED filament arrangement may further comprise a controller configured to individually control the plurality of first LED chips and the plurality of LED packages.

[0067] According to an embodiment of the present invention, the first LED chips have a first length, LI, and a first width, Wl, and wherein the second LED chips have a second length, L2, and a second width, W2, and wherein at least one of the following applies: (i) W1<W2 and L1<L2.

[0068] According to an embodiment of the present invention, the first LED filament section light has a first spatial light distribution having a first full-width-half-max, FWHM1, the second LED filament section light has a second spatial light distribution having a second full-width-half-max, FWHM2, and wherein FWHM2<FWHM1. For example, FWHM2<(FWHM1-3O degrees) may applies.

[0069] According to an embodiment of the present invention, there is provided a LED filament lamp or luminaire. The LED filament lamp or luminaire comprises a LED filament arrangement according to any one of the preceding embodiments. The LED filament lamp or luminaire further comprises a light-transmissive envelope at least partly enclosing the set of at least one LED filament, and a connector for electrically and mechanically connecting the LED filament lamp to a socket of a luminaire. Hence, the LED filament lamp or luminaire comprises a LED filament arrangement, which in turn comprises one or more LED filaments. The present embodiment is advantageous in that the LED filament lamp or luminaire, comprising the LED filament(s), combines the aspects of a desired light emission and aesthetical appearance provided via the LED filament arrangement and / or via the feature(s) of the lamp or luminaire.

[0070] According to an example of the present invention, at least one of the first LED filament section and the second LED filament section may appear white when the LED 2024PF80347

[0071] 12 filament arrangement is in an off-state. Hence, the properties of the first and / or second LED filament section(s) may cause them to appear white or whitish when the LED filament is in an off-state. Phrased differently, the first and / or second LED filament section(s) may be rendered white or whitish (for an observer of the LED filament arrangement), when the LED filament arrangement is in an off-state (i.e. switched off). The obtained effect is a visually attractive off-state white appearance of the LED filament arrangement. More specifically, the LED filament arrangement may hereby attain a vintage look, and it will be appreciated that a decor style LED filament arrangement of this kind is considered very attractive. The present example is further advantageous in that it may also provide an improved optical performance. Hence, the present example is advantageous in that the white color as provided renders the LED filament arrangement attractive for an observer, and that an improved lighting performance may also be attained.

[0072] According to an example of the present invention, at least one of the first elongated encapsulant may comprise a first light scattering material configured to at least partially diffusely transmit and at least partially diffusely reflect the emitted first LED chip light, and the package encapsulant may comprise a second light scattering material configured to at least partially diffusely transmit and at least partially diffusely reflect the emitted second LED chip light, is fulfilled. Hence, the first and / or second light scattering material of the first elongated encapsulant and / or the package encapsulant, respectively, may be configured or arranged to at least partially diffusely transmit and diffusely reflect the first and / or second LED chip light. By “diffusely transmit”, it is here meant that the first and / or second light scattering material is configured to transmit the light whilst providing diffusion of the light upon transmission. By “diffusely reflect”, it is here meant that the first and / or second light scattering material is configured to reflect the light whilst providing diffusion of the light upon reflection. The present example is advantageous in that the diffusive property of the first elongated encapsulant and / or the package encapsulant may achieve an omnidirectional, or at least almost omnidirectional, light distribution via the diffusive transmission and reflection.

[0073] According to an example of the present invention, the set of at least one LED filament may comprise N LED filaments, wherein 3 < N < 5. Hence, set of LED filament(s) may comprise between three and five LED filaments.

[0074] Further objectives of, features of, and advantages with, 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 2024PF80347

[0075] 13 invention can be combined to create embodiments other than those described in the following.

[0076] BRIEF DESCRIPTION OF THE DRAWINGS

[0077] This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiment(s) of the invention.

[0078] Fig. 1 shows a LED filament lamp according to the prior art,

[0079] Figs. 2a, 2d and 2e schematically show LED filament arrangements according to exemplifying embodiments of the present invention,

[0080] Figs. 2b and 2c schematically show cross-sections of LED filaments of a LED filament arrangement according to an exemplifying embodiment of the present invention, and

[0081] Fig. 3 shows a LED filament lamp or luminaire comprising a LED filament arrangement according to an exemplifying embodiment of the present invention.

[0082] DETAILED DESCRIPTION

[0083] Fig. 1 shows a LED filament lamp 10 according to the prior art, comprising a plurality of LED filaments 20. LED filament lamps 10 of this kind are highly appreciated as they are very decorative, as well as providing numerous advantages compared to incandescent lamps such as a longer operational life, a reduced power consumption, and an increased efficiency related to the ratio between light energy and heat energy. However, it is of interest to improve the properties of the light distribution emitted from the LED filaments 20, and to even further augment the decorative appearance and / or aspect of the LED filaments 20 and / or the LED filament lamps 10.

[0084] Figs. 2a, 2d and 2e schematically show LED filament arrangements 100 according to exemplifying embodiments of the present invention.

[0085] Fig. 2a schematically shows a LED filament arrangement 100 configured to provide, in an on-state, LED filament arrangement light 110. The LED filament arrangement light 110 may be white light having a correlated color temperature, CCT, in a range from 2000 to 6500 K, and preferably a color rendering index, CRI, of at least 80, or at least 85. The LED filament arrangement 100 comprises a set 120 of at least one LED filament 130a, b. Here, in Fig. 2a, the set 120 of LED filament(s) 130a,b is exemplified as comprising two LED filaments 130a, b. However, the number is arbitrary, and according to an example, the LED filament arrangement 100 may comprise N LED filaments, wherein e.g. 2 < N < 7 or 3 < N < 5. The LED filaments 130a,b are configured to provide, during operation, LED 2024PF80347

[0086] 14 filament light 140. Preferably, each LED filament 130a, b has a length, LF, and a width, WF, wherein LF > 5WF or even LF > 10WF.

[0087] The LED filament 130a of the set 120 of the (two) LED filaments 130a,b, which extends along a length axis, LX, comprises a first LED filament section 150 configured to provide first LED filament section light 160. The first LED filament section 150 comprises a first elongated carrier section 170. The first elongated carrier section 170 may, for instance, be a substrate, that may be rigid (made from e.g. a polymer, glass, quartz, metal or sapphire) or flexible (e.g. made of a polymer or metal e.g. a film or foil). The first elongated carrier section 170 may be reflective or light transmissive, such as translucent and preferably transparent. The first LED filament section 150 comprises a plurality of first LED chips 180 schematically indicated by dashed rectangles. The plurality of first LED chips 180 preferably comprises more than 5 first LED chips 180, more preferably more than 8 first LED chips 180, and even more preferred more than 10 first LED chips 180. The first LED chips 180 may be (or correspond to) CoB LEDs. The first LED chips 180 are arranged on a first major surface 190 of the first elongated carrier section 170. For example, the plurality of first LED chips 180 may be glued on the first elongated carrier section 170. The plurality of first LED chips 180 is configured to emit first LED chip light 200, wherein the emitted first LED chip light 200 may be white LED light. The plurality of first LED chips 180 may be arranged on the first major surface 190 of the first elongated carrier section 170 in a linear array. Adjacently arranged first LED chips of the plurality of LED chips 180 may be separated by a distance, dl.

[0088] The first LED filament section 150 further comprises a first elongated encapsulant 210 at least partially covering the first major surface 190 of the first elongated carrier section 170 and at least partially enclosing the plurality of first LED chips 180. The first elongated encapsulant 210 comprises a first luminescent material configured to at least partly convert the emitted first LED chip light 200 into first converted light 220. The first elongated encapsulant 210 may be a polymer material which may be flexible such as for example a silicone. The luminescent material of the first elongated encapsulant 210 may be a light-scattering material, e.g. a polymer matrix comprising BaSO4, A12O3 and / or TiO2 particles. The luminescent material of the first elongated encapsulant 210 may be a phosphor such as an inorganic phosphor (e.g. YAG, LuAG, ECAS, KSiF, etc.) and / or quantum dots or rods. The phosphor may further be e.g. a (blue) green / yellow and / or red phosphor. Although not shown, a concentration of the luminescent material in the first elongated encapsulant 210 may vary over the length of the LED filament(s) 130a-d. 2024PF80347

[0089] 15

[0090] Fig. 2b schematically shows a cross section of the LED filament 130a perpendicular to the length axis, LX, thereof. Fig. 2b indicates a first LED chip 180 arranged on the first elongated carrier section 170, wherein the first LED chip 180 is configured to emit first LED chip light 200. The first elongated encapsulant 210 at least partially covers the first major surface 190 of the first elongated carrier section 170 and at least partially encloses the first LED chip 180. The first elongated encapsulant 210 comprises a first luminescent material configured to at least partly convert the emitted first LED chip light 200 into first converted light 220.

[0091] In Fig. 2a, the LED filament 130b of the set 120 of the (two) LED filaments 130a, b, which extends along a length axis, LX, comprises a second LED filament section 230. The second LED filament section 230 is configured to provide second LED filament section light 240. The second LED filament section 230 comprises a second elongated carrier section 250. It should be noted that the second elongated carrier section 250 may have one or more properties and / or features in common with the first elongated carrier section 170 of the first LED filament section 150 of the LED filament 130a. The second LED filament section 230 further comprises electrically conductive tracks 260 arranged on a first major surface 270 of the second elongated carrier section 250. The second LED filament section 230 further comprises a plurality of LED packages 280 electrically connected to the electrically conductive tracks 260. The plurality of LED packages 280 preferably comprises more than 5 LED packages 280, more preferably more than 8 LED packages 280, and even more preferred more 10 LED packages 280.

[0092] Each LED package of the plurality of LED packages 280 comprises a package carrier. It should be noted that the package carrier may have one of more properties and / or features in common with the first and / or second elongated carrier section(s) 170, 250. Each LED package 280 further comprises a second LED chip 300 arranged on the package carrier, wherein the second LED chip 300 is configured to emit second LED chip light 310. The emitted second LED chip light 310 may be white LED light. The LED package 280 may be (or correspond to) SMD LEDs. Adjacently arranged second LED chips 300 of the plurality of LED packages 280 may be separated by a distance d2. The distance, dl, between adjacently arranged first LED chips 180, dl, and the distance, d2, between adjacently arranged second LED chips 300, may fulfil dl < d2. Each LED package 280 further comprises a package encapsulant 320 at least partly covering the second LED chip 300. The package encapsulant 320 comprises a second luminescent material configured to at least partly convert the emitted second LED chip light 310 into second converted light 330. 2024PF80347

[0093] 16

[0094] Fig. 2c schematically shows a cross section of the LED filament 130b perpendicular to the length axis, LX, thereof. More specifically, Fig. 2c shows components of the LED filament 130b and the LED package 280 of the second LED filament section shown in Fig. 2a. The LED package 280 comprises a package carrier 290, and a second LED chip 300 arranged on the package carrier 290. Electrically conductive tracks may be arranged on a first major surface of the second elongated carrier section 250, and the LED package 280 is soldered 340 to the electrical tracks. The second LED chip 300 is configured to emit second LED chip light 310. The emitted second LED chip light 310 may be white LED light. The LED package 280 may be (or correspond to) SMD LEDs. Each LED package 280 further comprises a package encapsulant 320 at least partly covering the second LED chip 300. The package encapsulant 320 comprises a second luminescent material configured to at least partly convert the emitted second LED chip light 310 into second converted light 330. The LED package 280 as exemplified in Fig. 2c further comprises a reflective cup 350, such as a white reflective cup 350. The (white) reflective cup 350 may partially enclose the second LED chip 300 and the package encapsulant 320.

[0095] According to the example of the LED filament arrangement shown in Fig. 2a, the first and second LED filament section lights 160, 240 may be emitted in different directions. Furthermore, the first LED filament section light 160 may have a first correlated color temperature, CCT1, and the second LED filament section light 240 may have a second correlated color temperature, CCT2, wherein |CCT1 - CCT2| < 300 K. The first and second elongated carriers sections 170, 250 may furthermore differ in thickness, T, width, W, and / or thermal conductivity, KTC.

[0096] Fig. 2d schematically shows a LED filament arrangement 100 according to an exemplifying embodiment of the present invention. It will be appreciated that the LED filament arrangement 100 as exemplified in Fig. 2d corresponds to the LED filament arrangement 100 in Fig. 2a, and it is hereby also referred to Fig. 2a for an increased understanding of the LED filament arrangement 100 and for references thereof.

[0097] In Fig. 2d, the set of at least one LED filament of the LED filament arrangement 100 comprises a single (third) LED filament 130c. It will be appreciated that the LED filament 100 may comprise a plurality of the type or sort of the LED filament 130c, but that Fig. 2d only shows one of these. The LED filament 130c comprises a first LED filament section 150 comprising a CoB LED architecture as described in Figs. 2a-c and the associated text(s). The LED filament 130c further comprises a second LED filament section 230 comprising a SMD LED architecture as described in Figs. 2a-c and the associated text(s). In 2024PF80347

[0098] 17

[0099] Fig. 2d, the first LED filament section 150 and the second LED filament section 230 of the LED filament 130c are colinearly arranged along the length axis, LX.

[0100] Fig. 2e schematically shows a LED filament arrangement 100 according to an exemplifying embodiment of the present invention. It will be appreciated that the LED filament arrangement 100 as exemplified in Fig. 2e corresponds to the LED filament arrangement 100 in Fig. 2a, and it is hereby also referred to Fig. 2a for an increased understanding of the LED filament arrangement 100 and for references thereof.

[0101] In Fig. 2e, the set of at least one LED filament of the LED filament arrangement 100 comprises a single (third) LED filament 130d. It will be appreciated that the LED filament 100 may comprise a plurality of the type or sort of the LED filament 130d, but that Fig. 2e only shows one of these. The LED filament 130d comprises a first LED filament section 150 comprising a CoB LED architecture as described in Figs. 2a-c and the associated text(s). The LED filament 130d further comprises a second LED filament section 230 comprising a SMD LED architecture as described in Figs. 2a-c and the associated text(s). The first LED filament section 150 and the second LED filament section 230 of the LED filament 130d are arranged in parallel and adjacent to each other. Hence, the first and second LED filament sections 150, 230 extend parallel to the length axis, LX.

[0102] Although Fig. 2e shows a (single) first LED filament section 150 and a (single) second LED filament section 230, it should be noted that the LED filament arrangement 100 alternatively may comprise a plurality of first LED filament sections and a plurality of second LED filament sections. In such a case, the LED filament arrangement 100 may comprise a first circuitry connecting the LED filament sections of the plurality of first LED filament sections, and a second circuitry connecting the LED filament sections of the plurality of second LED filament sections.

[0103] Fig. 3 schematically shows a LED filament lamp or luminaire 500 according to an embodiment of the present invention. The LED filament lamp or luminaire 500 comprises a LED filament arrangement 100 according to any one of the previously described embodiments. The LED filament lamp or luminaire 500 further comprises a light- transmissive envelope 510, which is exemplified as being bulb-shaped. The light- transmissive envelope 510 at least partially encloses the LED filament arrangement 100. The LED filament lamp or luminaire 500 further comprises a connector 520 for electrically and mechanically connecting the LED filament lamp or luminaire 500 to a socket. The LED filament lamp or luminaire 500 may further comprise a controller 400 coupled to the set of LED filament(s) of the LED filament arrangement 100 and which is configured to control the 2024PF80347

[0104] 18 luminous flux of the LED filament light. The controller 400 is schematically indicated by a dashed rectangle in the connector 520, but it should be noted that the controller 400 may be arranged at substantially any position or place. The controller 400 may, for example, be able to control each LED filament of the set of LED filament(s) of the LED filament arrangement 100 individually.

[0105] The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, one or more of the LED filament arrangement 100, the first LED filament section 150, the second LED filament section 230, etc., may have different shapes, dimensions and / or sizes than those depicted / described.

Claims

1. 2024PF8034719CLAIMS:

1. A light emitting diode, LED, filament arrangement (100) configured to provide, in an on-state, LED filament arrangement light (110), the LED filament arrangement comprising a set (120) of at least one LED filament (130a-d) configured to provide, during operation, LED filament light (140), wherein the set of the at least one LED filament comprises a first LED filament section (150) configured to provide first LED filament section light (160), comprising a first elongated carrier section (170), a plurality of first LED chips (180) arranged on a first major surface (190) of the first elongated carrier section, wherein the plurality of first LED chips is configured to emit first LED chip light (200), a first elongated encapsulant (210) at least partially covering the first major surface of the first elongated carrier section and at least partially enclosing the plurality of first LED chips, wherein the first elongated encapsulant comprises a first luminescent material configured to at least partly convert the emitted first LED chip light into first converted light (220), and a second LED filament section (230) configured to provide second LED filament section light (240), comprising a second elongated carrier section (250), electrically conductive tracks (260) arranged on a first major surface (270) of the second elongated carrier section, a plurality of LED packages (280) electrically connected to the electrically conductive tracks, wherein each LED package of the plurality of LED packages comprises a package carrier (290), a second LED chip (300) arranged on the package carrier, wherein the second LED chip is configured to emit second LED chip light (310), and2024PF8034720 a package encapsulant (320) at least partly covering the second LED chip, wherein the package encapsulant comprises a second luminescent material configured to at least partly convert the emitted second LED chip light into second converted light (330), wherein the plurality of first LED chips is glued on the first elongated carrier section and each LED package of the plurality of LED packages is soldered (340) to the electrical tracks.

2. The LED filament arrangement according to claim 1, wherein the set of at least one LED filament comprises at least one first LED filament comprising the first LED filament section, and at least one second LED filament comprising the second LED filament section.

3. The LED filament arrangement according to claim 1 or 2, wherein the set of at least one LED filament comprises at least one third LED filament comprising the first LED filament section and the second LED filament section.

4. The LED filament arrangement according to claim 3, wherein one of the first LED filament section and the second LED filament section are colinearly arranged, and the first LED filament section and the second LED filament section are arranged in parallel and adjacent to each other, is fulfilled.

5. The LED filament arrangement according to any one of the preceding claims, wherein the first LED chips have a first length, LI, and a first width, Wl, and wherein the second LED chips have a second length, L2, and a second width, W2, and wherein at least one of the following applies: (i) W 1<W2 and L1<L2.

6. The LED filament arrangement according to any one of the preceding claims, wherein the first LED filament section light has a first spatial light distribution having a first full-width-half-max, FWHM1, the second LED filament section light has a second spatial2024PF8034721 light distribution having a second full-width-half-max, FWHM2, and wherein FWHM2<FWHM1.

7. The LED filament arrangement according to any one of the preceding claims, wherein the first LED filament section is a chip on board, CoB, and each LED package of the plurality of LED packages is a surface mounted device LED, SMD.

8. The LED filament arrangement according to any one of the preceding claims, wherein each LED package of the plurality of LED packages comprises a reflective cup (350) and wherein the first LED filament section (150) is free from a reflective cup.

9. The LED filament arrangement according to any one of the preceding claims, wherein at least one of the following applies: the thickness of the second elongated carrier is higher than the thickness of the first elongated carrier; the width of the second elongated carrier is higher than the width of the first elongated carrier; and the thermal conductivity of the second elongated carrier is higher than the thermal conductivity of the first elongated carrier.

10. The LED filament arrangement according to any one of the preceding claims, wherein a distance, dl, between adjacently arranged first LED chips of the plurality of LED chips, and a distance, d2, between adjacently arranged second LED chips of the plurality of LED packages, fulfil dl < d2.

11. The LED filament arrangement according to any one of the preceding claims, wherein the first and second LED filament section lights are emitted in different directions.2024PF803472212. The LED filament arrangement according to any one of the preceding claims, wherein the first LED filament section light has a first correlated color temperature, CCT1, and the second LED filament section light has a second correlated color temperature, CCT2, wherein |CCT1 - CCT2| < 300 K.

13. The LED filament arrangement according to any one of the preceding claims, further comprising a plurality of first LED filament sections, and a first circuitry connecting the LED filament sections of the plurality of first LED filament sections, and a plurality of second LED filament sections, and a second circuitry connecting the LED filament sections of the plurality of second LED filament sections.

14. The LED filament arrangement according to any one of the preceding claims, further comprising a controller (400) coupled to the set of at least one LED filament, wherein the controller is configured to individually control each LED filament of the set of at least one LED filament.

15. A LED filament lamp (500), comprising a LED filament arrangement according to any one of the preceding claims, a light-transmissive envelope (510) at least partly enclosing the set of at least one LED filament, and a connector (620) for electrically and mechanically connecting the LED filament lamp to a socket of a luminaire.

Images