LED filament luminaire comprising a LED filament arrangement
Patent Information
- Application Number
- PCT/EP2026/060295
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-09-15
- Filing Date
- 2026-04-09
- Publication Date
- 2026-10-22
Smart Images
Figure EP2026060295_22102026_PF_FP_ABST
Abstract
Description
[0001] 2025PF80249
[0002] 1
[0003] LED filament luminaire comprising a LED filament arrangement
[0004] FIELD OF THE INVENTION
[0005] The present invention generally relates to a light emitting diode, LED, filament luminaire. More specifically, the present invention relates to a LED filament luminaire comprising a LED filament arrangement.
[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] Recently, there has been a surge in the interest of using LED filaments in lamps or luminaires, using the virtuous aspects and features of LED filaments in these lighting devices or arrangements. However, it is desired to even further improve the performance, functionality and / or appearance of LED filaments and / or LED filament lamps / luminaires. More specifically, due to high demands on performance and functionality, there is a particular desire to improve the thermal management of the LED filament devices / arrangements in order to obtain higher efficiency and / or brightness. Furthermore, it is2025PF80249
[0010] 2
[0011] desirable to improve the mechanical stability and robustness of the LED filament device s / arrangements .
[0012] Based on the above, there is a wish to provide LED filaments and / or LED filament lamps / luminaires with an improved performance, functionality and / or appearance. Consequently, it is desirable that the LED filaments and / or LED filament lamps / luminaires provide an efficient LED filament lighting during operation, and an improved performance and / or functionality of the light emission and / or light distribution from the LED filaments.
[0013] SUMMARY OF THE INVENTION
[0014] It is of interest to explore the possibility of combining one or more of the numerous advantages of LED filament arrangements comprising LEDs, whilst improving the LED filaments’ performance and / or functionality, and improving the appearance and / or the decorative aspect of the LED filaments and / or the LED filament lamps. In particular, it is of interest to improve the efficiency, brightness and / or mechanical stability of the LED filament luminaires / lamps.
[0015] This and other objects are achieved by providing a LED filament luminaire having the features in the independent claim. Preferred embodiments are defined in the dependent claims.
[0016] According to the present invention, there is provided a light emitting diode, LED, filament luminaire configured to provide, during operation, LED filament luminaire light. The LED filament luminaire comprises a LED filament arrangement configured to provide LED filament light and a light exit window. The LED filament arrangement comprises a light-transmissive board carrier comprising a first edge, a second edge, oppositely arranged the first edge, a first major surface, and a second major surface, opposite to the first major surface. The first and second major surfaces are arranged between the first and second edges. The first major surface comprises a first peripheral portion arranged adjacent to the first edge, and the second major surface comprises a second peripherical portion arranged adjacent to the first edge. The LED filament arrangement further comprises an array of a plurality of light emitting diodes, LEDs, arranged on the first peripheral portion, wherein the plurality of LEDs is configured to emit LED light. The LED filament arrangement further comprises an elongated encapsulant at least partially covering the first peripheral portion, at least partially covering the second peripheral portion, and at least partially enclosing the plurality of LEDs. The elongated encapsulant comprises at least one of a luminescent material configured to at least partly convert the emitted LED light into2025PF80249
[0017] 3
[0018] converted light, and a light-scattering material configured to at least partly scatter the emitted LED light into scattered light. The first edge is arranged closer to the light exit window than the second edge. The LED filament luminaire may further comprise a collimator configured to collimate or shape at least part of the LED filament light to provide the luminaire light.
[0019] Thus, the present invention is based on the idea of providing a LED filament luminaire with a LED filament arrangement, which in turn comprises a light-transmissive board carrier. A plurality of LEDs is arranged on a peripheral portion of the light-transmissive board carrier, and an elongated encapsulant at least partially encloses the plurality of LEDs.
[0020] The present invention is advantageous in that the light-transmissive board carrier efficiently improves the LED filament luminaire’s strength, solidity, robustness and reliability. Generally, it should be noted that carrier material(s) may be susceptible to break during assembly or use. Via the provision of a board carrier, according to the present invention, the strength, solidity and reliability of the LED filament luminaire is increased. Consequently, the functionality and service life of the LED filament luminaire are improved. The LED filament luminaire hereby provides an exceptional functionality and lighting performance, whilst achieving a decorative and aesthetically appealing LED filament look and LED filament light.
[0021] The present invention is particularly advantageous in that the LED filament luminaire, via the light-transmissive board carrier, achieves an efficient thermal management. Consequently, by virtue of this improved thermal management, the LED filament luminaire attains an improved functionality and lighting performance by a higher efficiency and / or brightness.
[0022] The present invention is further advantageous in that the LED filament luminaire achieves an improved performance and / or functionality of the light emission and / or light distribution from the LED filament arrangement, as well as a decorative effect of the LED filament luminaire during operation (on-state). It will be appreciated that one or more properties of the light-transmissive board carrier, encapsulant, etc., may be set or tuned for optimizing the performance and / or functionality of the light emission and / or light distribution from the LED filament luminaire. Analogously, one or more properties of the light-transmissive board carrier, encapsulant, etc., may be set or tuned for optimizing the aesthetical attractiveness of the LED filament luminaire during operation thereof.
[0023] In case the LED filament arrangement of the LED filament luminaire comprises a collimator configured to collimate at least part of the LED filament light to2025PF80249
[0024] 4
[0025] provide the luminaire light, the performance, functionality and / or appearance of the LED filament luminaire and / or the luminaire light may be improved even further.
[0026] 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 luminaire as disclosed.
[0027] The present invention is further advantageous in that the LED filament luminaire of the present invention comprises relatively few components. The low number of components is advantageous in that the LED filament luminaire is relatively inexpensive to fabricate. Moreover, the low number of components of the LED filament luminaire 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.
[0028] There is provided a light emitting diode, LED, filament luminaire configured to provide, during operation, LED filament luminaire light. The LED filament luminaire comprises a LED filament arrangement configured to provide LED filament light. The LED filament luminaire comprises a light exit window. By “light exit window”, it is here meant substantially any opening, aperture, cover, lens, or the like, via which the LED filament light is arranged to exit. The LED filament luminaire arrangement comprises a light-transmissive board carrier. By “board carrier”, it is here meant that the carrier is shaped as a (flat) board, plate, or the like. By “light-transmissive board carrier”, it is here meant that the board carrier is translucent (e.g., transparent), wherein the board carrier furthermore may be lightdiffusing. The light-transmissive board carrier may, for instance, be a substrate, that may be rigid (made from, e.g., a polymer, glass, quartz, ceramic, or sapphire). The (rigid) light-transmissive board carrier preferably comprises a thermally conductive material (e.g., (white) aluminum oxide) having a thermal conductivity of at least 2 W / m-K or at least 5 W / m-K or at least 10 W / m-K.
[0029] The light-transmissive board carrier comprises a first edge and a second edge, oppositely arranged the first edge, a first major surface, and a second major surface, opposite to the first major surface, and wherein the first and second major surfaces are arranged between the first and second edges. Hence, the light-transmissive board carrier comprises first and second major surfaces defined (delimited) by first and second edges of the light-transmissive board carrier. The first major surface comprises a first peripheral portion arranged adjacent to the first edge, and the second major surface comprises a second peripherical portion arranged adjacent to the first edge. Hence, the first and second peripheral portions constitute portions or parts of the light-transmissive board carrier provided in a2025PF80249
[0030] 5
[0031] vicinity of the first edge thereof. The LED filament arrangement further comprises an array of a plurality of light emitting diodes, LEDs, arranged on the first peripheral portion. By the term “array”, it is here meant a linear arrangement or chain of LEDs, or the like. The plurality of LEDs is configured to emit LED light during operation.
[0032] The LED filament arrangement further comprises an elongated encapsulant at least partially covering the first peripheral portion, at least partially covering the second peripheral portion, and at least partially enclosing the plurality of LEDs. 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 at least a portion of the board carrier and / or the plurality of LEDs. For example, the LED filament arrangement may comprise only one encapsulant, i.e. the elongated encapsulant. The encapsulant may be a polymer material which may be flexible such as for example a (crosslinked) silicone e.g. (crosslinked) polydimethylsiloxane (PDMS), polydiphenylsiloxane (PDPS), polymethylphenylsiloxane (PMPS) or combinations thereof. The encapsulant comprises a luminescent material configured to at least partly convert the emitted LED light into converted light and / or a light-scattering material configured to at least partly scatter the emitted LED light into scattered light. The luminescent material of the encapsulant may be a phosphor such as an inorganic phosphor (e.g. YAG, LuAG, EC AS, KSiF, etc.) and / or quantum dots or rods. The phosphor may further be e.g. a (blue) green / yellow and / or red phosphor. The light-scattering material may be e.g. a polymer matrix comprising BaSCU, AI2O3 and / or TiCL particles.
[0033] The first edge of the light-transmissive board carrier is arranged closer to the light exit window than the second edge of the light-transmissive board carrier. Hence, a (first) distance, Di, between the first edge and the light exit window and a (second) distance, D2, between the second edge and the light exit window fulfil Di < D2.
[0034] The LED filament luminaire may optionally comprise a collimator configured to collimate at least part of the LED filament light to provide the luminaire light.
[0035] According to an embodiment of the present invention, the elongated encapsulant may at least partially e.g. fully cover the first edge. Hence, the elongated encapsulant may at least partially cover the first and second peripheral portions of the light-transmissive board carrier as well as the first edge. Thus, it is preferred that the second edge is not be covered (by the or an elongated encapsulant). The present embodiment is advantageous in that the LED filament light emitted via the first edge is converted and / or scattered by the encapsulant, thereby even further enhancing the lighting effect of the LED2025PF80249
[0036] 6
[0037] filament luminaire. The first edge may not be visible e.g. when looking into the light exit window of the luminaire, because the first edge may be hidden by the elongated encapsulant.
[0038] According to an embodiment of the present invention, the elongated encapsulant may consist of a single (e.g. one-piece or monolithic) encapsulant layer. Hence, the LED filament luminaire may comprise a single, common encapsulant. The present embodiment is advantageous by its relatively simple construction, still achieving the desired light distribution properties and aesthetical attractiveness of the LED filament luminaire. The present embodiment is further advantageous by its convenient manufacturing, e.g., via partly-overmolding, whereby the partly-overmolding architecture has the advantage of an improved filament look in the luminaire.
[0039] According to an embodiment of the present invention, the elongated encapsulant may comprise a first encapsulant layer at least partially covering the first peripheral portion and at least partially enclosing the plurality of LEDs, and a second encapsulant layer at least partially covering the second peripheral portion. Hence, the elongated encapsulant may comprise (at least) two layers. The present embodiment is advantageous in that the first and second encapsulant layers may contribute to the customization of the light distribution properties and / or aesthetical attractiveness of the LED filament luminaire, e.g., by having different properties such as different dimension(s), material(s), etc. The present embodiment is further advantageous in that the emission of the LED light may be converted and / or scattered by the elongated encapsulant even via transmission through the second peripheral portion of the board carrier due to its light-transmissive properties. Hence, by virtue of the light-transmissive board carrier, the emitted LED filament light may be substantially omnidirectional, and the elongated encapsulant may hereby achieve an even more improved LED filament light emission and / or an even more augmented LED filament attractiveness.
[0040] According to an example of the present invention, the first encapsulant layer may be configured to provide a first portion of the LED filament light with a first CCT, CCTi, and the second encapsulant layer may be configured to provide a second portion of the LED filament light with a second CCT, CCT2, wherein |CCTi - CCT2I > 500 K. For example, the first encapsulant layer may be configured to provide relatively cold white light and the second encapsulant layer may be configured to provide relatively warm white light. The present example is advantageous in that the difference in CCT for the LED filament light provided by the first and second encapsulant layers achieve a particularly attractive lighting effect.2025PF80249
[0041] 7
[0042] According to an embodiment of the present invention, the second encapsulant layer may at least partly enclose the first encapsulant layer. Hence, the first and second encapsulant layers may be stacked. Consequently, at least part of the LED light emitted by the plurality of LEDs may be converted and / or scattered by the first encapsulant layer, and thereafter be converted and / or scattered by the second encapsulant layer. For example, the first encapsulant layer, arranged beneath the second encapsulant layer, may be transparent for an improved light distribution, especially to guide the light to the other side of the light-transmissive board carrier. The present embodiment of first and second encapsulant layers is advantageous in that the lighting and / or aesthetical properties of the LED filament luminaire may be customized even further.
[0043] According to an embodiment of the present invention, the first and second encapsulant layers may differ in at least one of luminescent material type and / or luminescent material concentration, and light-scattering material type and / or light-scattering material concentration. The present embodiment is advantageous in that the different property(ies) of the first and second encapsulant layers may even further contribute to the customization of the light distribution properties and / or aesthetical attractiveness of the LED filament luminaire.
[0044] According to an embodiment of the present invention, a first portion of the elongated encapsulant at least partially covering the first peripheral portion may have a first thickness, Tl, and a second portion of the elongated encapsulant at least partially covering the second peripheral portion may have a second thickness, T2, wherein T2 < TL Hence, the first portion of the elongated encapsulant may be thinner than the second portion of the elongated encapsulant. The present embodiment is advantageous in that the first and second portions of the elongated encapsulants are dimensioned according to the (position of the) plurality of LEDs, being arranged on the first peripheral portion of the first major surface.
[0045] According to an embodiment of the present invention, a surface area, Ai, of the first peripheral portion, a surface area, A2, of the first major surface, a surface area, A3, of the second peripheral portion, and a surface area, A4, of the second major surface, may fulfil A1 / A2 < 0.3 and A3 / A4 < 0.3, or A1 / A2 < 0.1 and A3 / A4 < 0.1, or A1 / A2 < 0.05 and A3 / A4 < 0.05. Hence, the surface area, Ai, of the first peripheral portion is much smaller than the surface area, A2, of the first major surface and / or the surface area, A3, of the second peripheral portion is much smaller than the surface area, A4, of the second major surface. The present embodiment is advantageous in that (only) the first and second peripheral portions2025PF80249
[0046] 8
[0047] are provided for the plurality of LEDs and encapsulant(s), whereby the opposing edge portion may be provided for insertion into a holder.
[0048] According to an example of the present invention, 0.7 < A1 / A3 < 0.3 or 0.8 < A1 / A3 < 1.2 or 0.9 < A1 / A3 < 1.1.
[0049] According to an embodiment of the present invention, the board carrier may have a thickness, T, in a range of 0.1-4 mm, such as 0.2-2 mm, a length, L, in a range of 20-200 mm, such as 40-150 mm, and / or a width, W, in a range of 5-150 mm, such as 10-100 mm. It will be appreciated that the thickness, T, the length, L and the width, W, constitute the (perpendicular) dimensions of the light-transmissive board carrier, i.e. the dimensions along the Cartesian coordinates x, y, z. The elongated encapsulant may elongate along the length (dimension) of the board carrier. The present embodiment is advantageous in that the dimensions of the light-transmissive board carrier provide an improved mechanical stability of the LED filament luminaire.
[0050] According to an example of the present invention, the elongated encapsulant may have a first width, Wl, and the light-transmissive board carrier may have a second width, W2, wherein W2 >3-W 1 or W2 > 6-W 1 or W2 > 9-W 1. Wl may be in a range from 1-4 mm or 1-3 mm. W2 may be in a range from 10-100 mm or 30-100 mm. For example, Wl may be 2 mm and W2 may be 30 mm.
[0051] According to an example of the present invention, a ratio, R=Wi / W between a width, Wi, covered by the elongated encapsulant and the width, W, of the board carrier, fulfils R< 0.3.
[0052] According to an example of the present invention, the array of a plurality of LEDs may extend in a direction of a length axis of the light-transmissive board carrier.
[0053] According to an embodiment of the present invention, the LED filament luminaire may further comprise electrical tracks connected to the plurality of LEDs and provided at least partly on the first major surface, and electrodes connected to the electrical tracks and extending on the first major surface. The present embodiment is advantageous in that the provision of electrical tracks and electrodes on / in the LED filament luminaire entails a convenient electrical connection of the LED filament luminaire and power supply to the plurality of LEDs.
[0054] According to an embodiment of the present invention, the LED filament luminaire may further comprise a third peripheral portion of the light-transmissive board carrier, e.g. arranged adjacent to the second edge, and a holder arranged to hold the LED filament arrangement upon insertion of the third peripheral portion into the holder. The2025PF80249
[0055] 9
[0056] present embodiment is advantageous in that the holder is configured to firmly hold the LED filament arrangement, thereby contributing to the robustness and mechanical stability of the LED filament luminaire.
[0057] According to an embodiment of the present invention, the holder may comprise at least one of a clamping mechanism arranged to clamp the third peripheral portion, and a groove arranged to form-fittingly hold the third peripheral portion. Hence, the holder may comprise a clamping mechanism and / or a groove for accommodation and / or fastening of the third peripheral portion. The present embodiment is advantageous in that the clamping mechanism and / or groove achieve an even further augmented robustness and mechanical stability of the LED filament arrangement in the LED filament luminaire.
[0058] According to an embodiment of the present invention, the holder may comprise a heat sink configured to dissipate heat from the plurality of LEDs during operation. The heat sink may be in thermal and / or physical contact with the light-transmissive board carrier for efficient heat dissipation from the plurality of LEDs during operation. The present embodiment is advantageous in that the heat sink improves the heat management of the LED filament luminaire, and consequently improves the service life of the LED filament luminaire. The efficient heat management of the present embodiment further improves lighting properties of the LED filament luminaire such as efficiency and / or brightness.
[0059] According to an embodiment of the present invention, the electrodes may be arranged on the third peripheral portion of the light-transmissive board carrier and on the first major surface of the light-transmissive board carrier, and wherein the holder comprises electrical contacts arranged to come in electrical contact with the electrodes when holding the LED filament arrangement. The present embodiment is advantageous in that the provision of the electrodes and the electrical contacts confers a convenient and reliable electrical connection between the LED filament arrangement.
[0060] According to an embodiment of the present invention, the light-transmissive board carrier may extend perpendicular to the light exit window, the elongated encapsulant may be arranged in an optical center, OA, of the collimator, and / or the collimator may be a tapered reflector. The present embodiment is advantageous in that the symmetry of the configuration or construction of the LED filament luminaire even further augments the beneficial lighting properties and the aesthetical attractiveness thereof.
[0061] According to an example of the present invention, the light-transmissive board carrier may comprise a material selected from the group consisting of ceramic, glass, quartz2025PF80249
[0062] 10
[0063] and sapphire. Hence, the light-transmissive board carrier may comprise (a) light-transmissive ceramic (preferably AI2O3 or DGA), glass, quartz and / or sapphire. A particularly preferred material choice of the carrier for reasons of an optimal heat management may be a thermally conductive (white) alumina oxide. The present example is advantageous in that the mentioned material of the carrier has a high thermal conductivity, and provides an efficient thermal path to the ambient environment, which even further contributes to the thermal management of the LED filament luminaire.
[0064] According to an example of the present invention, the LED filament luminaire light may be white light having a correlated color temperature, CCT, in a range of 1700 -6500 K and e.g. a color rendering index, CRI, of least 80 or at least 85. The present example is advantageous in that this type of white light is often desired for lighting applications and / or aesthetical attractiveness.
[0065] According to an example of the present invention, the thermal conductivity, Tci, of the light-transmissive board carrier is at least 1 W / m-K. Preferably, the thermal conductivity, Tci, of the light-transmissive board carrier is at least 2 W / m-K, more preferred at least 10 W / m-K, and even more preferred at least 20 W / m-K. The high thermal conductivity of the light-transmissive board carrier provides superior thermal management such that the brightness and / or the efficiency of the LED filament luminaire (light) can be increased substantially.
[0066] According to an example of the present invention, the LED filament luminaire may comprise a plurality of LED filament arrangements, and a controller configured to individually control each array of plurality of LEDs of the respective LED filament arrangements. By “controller”, it is here meant any device, unit, or the like, which is able to control the LED arrays either by wire or via wireless technology. The present embodiment is advantageous in that the controller may conveniently and efficiently control the emitted LED light, thereby even further ameliorating the LED filament luminaire light and improving the appearance and / or the decorative aspect thereof.
[0067] 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 invention can be combined to create embodiments other than those described in the following.
[0068] BRIEF DESCRIPTION OF THE DRAWINGS2025PF80249
[0069] 11
[0070] 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.
[0071] Figs, la, lb, 2a, 2b, 3a-h and 4 show LED filament arrangements of a LED filament luminaire according to exemplifying embodiments of the present invention, and Figs. 5a and 5b show LED filament luminaires according to exemplifying embodiments of the present invention.
[0072] DETAILED DESCRIPTION
[0073] Fig. la shows a LED filament arrangement 120 of a LED filament luminaire 100 according to an exemplifying embodiment of the present invention. The LED filament luminaire 100 is configured to provide, during operation, LED filament luminaire light 110. The LED filament arrangement 120 comprises a light-transmissive board carrier 130. The light-transmissive board carrier 130 has a length, L (parallel to the axis, A), and a width, W (perpendicular to the axis, A). The length, L, is in a range of 25-200 mm, preferably in a range of 40-150 mm, the width, W, is in a range of 5-150 mm, preferably in a range of 10-100 mm, and the thickness, T, may be in a range of 0.1-3 mm, preferably in a range of 0.2-2 mm.
[0074] The light-transmissive board carrier 130 may be translucent and preferably transparent. The thermal conductivity of the light-transmissive board carrier 130, may be at least 1 W / m-K. Preferably, the thermal conductivity of the light-transmissive board carrier 120 is at least 2 W / m-K, more preferred at least 10 W / m-K, and even more preferred at least 20 W / m-K.
[0075] The LED filament arrangement 120 comprises an array of a plurality of light emitting diodes, LEDs 200, arranged to emit LED light 210. The array of the plurality of LEDs extends in a direction of the length, L, of the light-transmissive board carrier 130, i.e. parallel to the axis, A. It should be noted that the LED filament arrangement 120 may comprise substantially any number of array(s) of the plurality of LEDs 200. The (array(s) of the) plurality of LEDs 200 preferably comprises more than 5 LEDs, more preferably more than 8 LEDs, and even more preferred more than 10 LEDs. The plurality of LEDs 200 may be direct emitting LEDs which provide a color, e.g. blue LED light.
[0076] The LED filament arrangement 120 further comprises an elongated encapsulant 220 at least partially enclosing the plurality of LEDs 200. The encapsulant 220 may be a polymer material which may be flexible such as for example a (crosslinked) silicone e.g. (crosslinked) polydimethylsiloxane (PDMS), polydiphenylsiloxane (PDPS),2025PF80249
[0077] 12
[0078] polymethylphenylsiloxane (PMPS) or combinations thereof. The encapsulant 220 comprises a luminescent material configured to at least partly convert the emitted LED light 210 into converted light and / or a light-scattering material configured to at least partly scatter the emitted LED light 210 into scattered light. The luminescent material of the encapsulant 220 may be a phosphor such as an inorganic phosphor (e.g. YAG, LuAG, EC AS, KSiF, etc.) and / or quantum dots or rods. The phosphor may further be e.g. a (blue) green / yellow and / or red phosphor. The light-scattering material may be e.g. a polymer matrix comprising BaSCU, AI2O3 and / or TiCE particles. The LED filament luminaire light 110 may comprise the converted light and / or the scattered light, and part of the LED light 210. The LED filament luminaire light 110 may be white light having a correlated color temperature, CCT, in a range of 1700 - 6500 K and a color rendering index, CRI, of least 80. The LED filament luminaire light 110 may have a light distribution with a FWHM of at most 140 degrees or at most 120 degrees or at most 100 degrees. A ratio, R=Wi / W between a width, Wi, covered by the elongated encapsulant 220 and the width, W, of the board carrier 130, may fulfil R < 0.3.
[0079] Fig. lb shows a LED filament arrangement 120 of a LED filament luminaire 100 according to an exemplifying embodiment of the present invention. It should be noted that Fig. lb has many features in common with the LED filament arrangement 120 of Fig. la, and it is hereby also referred to Fig. la and the associated text for an increased understanding and for references omitted in Fig. lb. The LED filament arrangement 120 of the LED filament luminaire 100 in Fig. lb further comprises electrical tracks 300a, 300b connected to the plurality of LEDs and electrodes 310a, 310b connected to the electrical tracks 300a, 300b.
[0080] Figs. 2a and 2b show LED filament arrangements 120 of a LED filament luminaire 100 according to exemplifying embodiments of the present invention. It should be noted that Figs. 2a and 2b show the LED filament arrangements 120 of the LED filament luminaire(s) 100 of Fig. la in the direction of the axis, A, and it is hereby also referred to Fig. la and the associated text for an increased understanding.
[0081] The LED filament arrangement 120 of the LED filament luminaire 100 in Fig. 2a comprises is configured to provide LED filament light 125. The LED filament arrangement 120 comprises a light-transmissive board carrier 130. The light-transmissive board carrier 130 comprises a first edge 140 and a second edge 150, oppositely arranged the first edge 140. The light-transmissive board carrier 130 further comprises a first major surface 160 and a second major surface 170, opposite to the first major surface 160. The first and second major surfaces 160, 170 are arranged between the first and second edges 140, 150. The first major surface 160 comprises a first peripheral portion 180 arranged adjacent to2025PF80249
[0082] 13
[0083] the first edge 140, and the second major surface 170 comprises a second peripherical portion 190 arranged adjacent to the first edge 140. The LED filament arrangement 120 further comprises an array of a plurality of LEDs 200 arranged on the first peripheral portion 180, wherein the plurality of LEDs 200 is configured to emit LED light 210. The LED filament arrangement 120 further comprises an elongated encapsulant 220. The elongated encapsulant 220 (i) at least partially covers the first peripheral portion 180, (ii) at least partially covers the second peripheral portion 190, and (iii) at least partially encloses the plurality of LEDs 200. The elongated encapsulant 220 comprises (iv) a luminescent material configured to at least partly convert the emitted LED light 210 into converted light 230 and / or (v) a light-scattering material configured to at least partly scatter the emitted LED light 210 into scattered light 240. Here, the elongated encapsulant 220 is arranged flush with the first edge 140. The light-transmissive board carrier 130 further comprises a third peripheral portion 320 arranged adjacent to the second edge 150. The third peripheral portion 320 is arranged for insertion into a holder arranged to hold the LED filament arrangement 120 (as further disclosed in Fig.
[0084] 4, 5a and / or 5b and the associated text(s)).
[0085] In Fig. 2b, a first portion 450 of the elongated encapsulant 220 at least partially covers the first peripheral portion 180 and has a first thickness, Tl. Analogously, a second portion 460 of the elongated encapsulant 220 at least partially covers the second peripheral portion 190 has a second thickness, T2, wherein the relation between Tl and T2 may be T2 < TL Furthermore, a surface area, Ai, of the first peripheral portion 180, a surface area, A2, of the first major surface 160, a surface area, A3, of the second peripheral portion 190, and a surface area, A4, of the second major surface 170, may fulfil A1 / A2 < 0.3 and / or A3 / A4 < 0.3. The light-transmissive board carrier 130 may furthermore have a thickness, T, in a range of 0.1-3 mm, preferably in a range of 0.2-2 mm.
[0086] Figs. 3a-h show LED filament arrangements of a LED filament luminaire according to exemplifying embodiments of the present invention. It should be noted that Figs. 3a-h correspond to Figs. 2a and 2b, and it is hereby also referred to Figs. 2a and 2b and the associated text(s).
[0087] In Fig. 3a, the elongated encapsulant 220 is arranged flush with the first edge 140. Hence, the elongated encapsulant 220 does not cover the first edge 140, whereby the elongated encapsulant 220 comprises two separate portions or layers. More specifically, the elongated encapsulant 220 comprises a first encapsulant layer 220i at least partially covering the first peripheral portion and at least partially enclosing the plurality of LEDs. Furthermore, the elongated encapsulant 220 comprises a second encapsulant layer 2202 at least partially2025PF80249
[0088] 14
[0089] covering the second peripheral portion. The first and second encapsulant layers 220i, 2202 may have one or more different properties, e.g., for obtaining (first and second portions) of the LED filament light with different (first and second) CCTs (e.g., relatively cold and warm white light).
[0090] In Fig. 3b, the elongated encapsulant 220 is arranged flush with the first edge 140. The elongated encapsulant 220 comprises a first encapsulant layer 220i at least partially covering the first peripheral portion and at least partially enclosing the plurality of LEDs. The elongated encapsulant 220 further comprises a second encapsulant layer 2202 at least partially covering the second peripheral portion and at least partly enclosing the first encapsulant layer 220i.
[0091] The LED filament luminaire of Fig. 3c corresponds to the LED filament luminaire 100 of Fig. 3b in terms of dimensions and / or positions. In Fig. 3c, however, the first and second encapsulant layers 220i, 2202 of the elongated encapsulant 220 differ in (i) luminescent material type and / or luminescent material concentration and / or (ii) lightscattering material type and / or light-scattering material concentration.
[0092] In Fig. 3d, the elongated encapsulant 220, which consists of a single (common) encapsulant (layer), covers the first edge 140.
[0093] In Fig. 3e, the elongated encapsulant 220 comprises first and second encapsulant layers 220i, 2202. Both first and second encapsulant layers 220i, 2202 cover the first edge 140.
[0094] The LED filament luminaire of Fig. 3f corresponds to the LED filament luminaire 100 of Fig. 3e in terms of dimensions and / or positions. In Fig. 3f, however, the first and second encapsulant layers 220i, 2202 differ in (i) luminescent material type and / or luminescent material concentration and / or (ii) light-scattering material type and / or lightscattering material concentration.
[0095] In Fig. 3g, the elongated encapsulant 220 comprises first, second and third encapsulant layers 220i, 2202, 220s. All encapsulant layers 220i, 2202, 220s cover the first edge 140. The first encapsulant layer 220i at least partially covers the first peripheral portion and at least partially encloses the plurality of LEDs. The second encapsulant layer 2202 at least partially covers the second peripheral portion and at least partly encloses the first encapsulant layer 220i. The third encapsulant layer 220s at least partially encloses the second encapsulant layer 2202. The first, second and third encapsulant layers 220i, 2202, 220s differ in (i) luminescent material type and / or luminescent material concentration and / or (ii) lightscattering material type and / or light-scattering material concentration.2025PF80249
[0096] 15
[0097] In Fig. 3h, the elongated encapsulant 220 is arranged at a distance, d, from the first edge 140. Hence, the encapsulant 220 is not fully provided at one end of the light-transmissive board carrier.
[0098] Fig. 4 shows a plurality of LED filament arrangements 120 of a LED filament luminaire 100 according to an exemplifying embodiment of the present invention. Here, the LED filament arrangements 120 are constructed according to Fig. 3h, wherein the elongated encapsulant is arranged at a distance, d, from the first edge. The LED filament luminaire 100 further comprises a plurality of holders 510 arranged to hold the LED filament arrangements 120 upon insertion thereof in a respective holder 510. According to this example, the LED filament luminaire 100 further comprises a heat sink 600 configured to dissipate heat from the plurality of LEDs of the LED filament arrangements 120 during operation. Furthermore, according to this example, the two leftmost LED filament arrangements 120 are attached to the holder(s) 510 by their short ends of the light-transmissive board carrier, whereas the two rightmost LED filament arrangements 120 are attached to the holder(s) 510 by their long ends of the light-transmissive board carrier.
[0099] Fig. 5a schematically shows an insertion of a LED filament arrangement 120 into a LED filament luminaire 100 according to an exemplifying embodiment of the present invention. The LED filament arrangement 120 is hereby releasably attachable to a holder 510 of the LED filament luminaire 100 for mechanical and electrical connection of the LED filament arrangement 120. Upon attachment, the electrodes 310a, 310b of the LED filament arrangement 120 come into electrical contact with the electrical contacts 700a, 700b of the holder 510. It will be appreciated that Fig. 5b presents detailed information of the features of the LED filament luminaire 100, whereas Fig. 5a merely schematically discloses the releasable attachment of the LED filament arrangement 120.
[0100] Fig. 5b shows a LED filament luminaire 100 according to an exemplifying embodiment of the present invention. The LED filament luminaire 100 is configured to provide, during operation, LED filament luminaire light 110. The LED filament luminaire comprises a LED filament arrangement 120 configured to provide LED filament light 125. The LED filament arrangement 120 comprises a light-transmissive board carrier 130, an array of a plurality of LEDs 200 arranged on the light-transmissive board carrier 130, and an elongated encapsulant 220, in accordance with one or more of the embodiments or examples of the LED filament luminaire 100 of Figs. 1-4. The LED filament luminaire 100 in Fig. 5b further comprises a collimator 300 configured to collimate at least part of the LED filament light 125 to provide the LED filament luminaire light 110. The collimator 300 (reflector)2025PF80249
[0101] 16
[0102] partially encloses the LED filament arrangement 120, and is exemplified as being tapered (parabolic). The LED filament luminaire 100 further comprises a light exit window 400. The light-transmissive board carrier 130 extends perpendicular to the light exit window 400. The elongated encapsulant 220 of the LED filament arrangement 120 is arranged in an optical center, OA, of the collimator 300, wherein the dashed arrow indicates the focal line, FL, of the collimator 300. The first edge 140 of the light-transmissive board carrier 130 is arranged closer to the light exit window 400 than the second edge 150.
[0103] The light-transmissive board carrier 130 comprises a third peripheral portion 320 arranged adjacent to the second edge 150 of the light-transmissive board carrier 130. The LED filament luminaire 100 further comprises a holder 510 arranged to hold the LED filament arrangement 120 upon insertion of the third peripheral portion 320 into the holder 510. The holder 510 may comprise a clamping mechanism 520 arranged to clamp the third peripheral portion 320 and / or a groove 530 arranged to form-fittingly hold the third peripheral portion 320. According to this example of the LED filament luminaire 100, the holder 510 further comprises a heat sink 600 configured to dissipate heat from the plurality of LEDs 200 during operation.
[0104] 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 120, the light-transmissive board carrier 130, the encapsulant 220, etc., may have different shapes, dimensions and / or sizes than those depicted / described.2025PF80249
[0105] 17 REFERENCE LIST:
[0106] 100 LED filament luminaire
[0107] 110 LED filament luminaire light
[0108] 120 LED filament arrangement
[0109] 125 LED filament light
[0110] 130 Light-transmissive board carrier
[0111] 140 First edge
[0112] 150 Second edge
[0113] 160 First major surface
[0114] 170 Second major surface
[0115] 180 First peripheral portion
[0116] 190 Second peripheral portion
[0117] 200 LEDs
[0118] 210 LED light
[0119] 220 Elongated encapsulant
[0120] 2201 First encapsulant layer
[0121] 2202 First encapsulant layer
[0122] 230 Converted light
[0123] 240 Scattered light
[0124] 300 Collimator
[0125] 300a, 300b Electrical tracks
[0126] 310a, 310b Electrodes
[0127] 320 Third peripheral portion of the light-transmissive board carrier 400 Light exit window
[0128] 450 First portion of the elongated encapsulant
[0129] 460 Second portion of the elongated encapsulant
[0130] 510 Holder
[0131] 520 Clamping mechanism
[0132] 530 Groove
[0133] 600 Heat sink
[0134] 700a, 700b Electrical contacts
Claims
2025PF8024918CLAIMS:
1. A light emitting diode, LED, filament luminaire (100) configured to provide, during operation, LED filament luminaire light (110), the LED filament luminaire comprisinga LED filament arrangement (120) configured to provide LED filament light (125),a collimator (300), anda light exit window (400),wherein the LED filament arrangement (120) comprisesa light-transmissive board carrier (130) comprisinga first edge (140),a second edge (150), oppositely arranged the first edge (140),a first major surface (160), anda second major surface (170), opposite to the first major surface (160),wherein the first and second major surfaces (160, 170) are arranged between the first and second edges (140, 150), wherein the first major surface (160) comprises a first peripheral portion (180) arranged adjacent to the first edge (140), and the second major surface (170) comprises a second peripherical portion (190) arranged adjacent to the first edge (140),an array of a plurality of light emitting diodes, LEDs (200) arranged on the first peripheral portion (180), wherein the plurality of LEDs is configured to emit LED light (210),an elongated encapsulant (220)(i) at least partially covering the first peripheral portion (180), (ii) at least partially covering the second peripheral portion (190), and (iii) at least partially enclosing the plurality of LEDs (200), wherein the elongated encapsulant (220) comprises at least one of (iv) a luminescent material configured to at least partly convert the2025PF8024919emitted LED light (210) into converted light (230), and(v) a light-scattering material configured to at least partly scatter the emitted LED light (210) into scattered light (240),wherein the first edge (140) is arranged closer to the light exit window (400) than the second edge (150), andwherein the collimator (300) is configured to collimate at least part of the LED filament light (125) to provide the LED filament luminaire light (110), andwherein the LED filament luminaire further comprisinga third peripheral portion (320) of the board carrier (130), arranged adjacent to the second edge (150) , anda holder (510) arranged to hold the LED filament arrangement (120) upon insertion of the third peripheral portion (320) into the holder (510).
2. The LED filament luminaire according to claim 1, wherein the elongated encapsulant (220) at least partially covers the first edge (140).
3. The LED filament luminaire according to claim 2, wherein the elongated encapsulant (220) consists of a single encapsulant layer (220a).
4. The LED filament luminaire according to claim 1 or 2, wherein the elongated encapsulant (220) comprisesa first encapsulant layer (220i) at least partially covering the first peripheral portion (180) and at least partially enclosing the plurality of LEDs (200), anda second encapsulant layer (22O2) at least partially covering the second peripheral portion (190).
5. The LED filament luminaire according to claim 4, wherein the second encapsulant layer (22O2) at least partly encloses the first encapsulant layer (220i).
6. The LED filament luminaire according to claim 4 or 5, wherein the first and second encapsulant layers (220i, 22O2) differ in at least one of(i) luminescent material type and / or luminescent material concentration, and (ii) light-scattering material type and / or light-scattering material concentration.2025PF80249207. The LED filament luminaire according to any one of the preceding claims, whereina first portion (450) of the elongated encapsulant (220) at least partially covering the first peripheral portion (180) has a first thickness, Tl, anda second portion (460) of the elongated encapsulant (220) at least partially covering the second peripheral portion (190) has a second thickness, T2,wherein T2 < Tl.
8. The LED filament luminaire according to any one of the preceding claims, wherein(i) a surface area, Ai, of the first peripheral portion (180), (ii) a surface area, A2, of the first major surface (160),(iii) a surface area, A3, of the second peripheral portion (190), and (iv) a surface area, A4, of the second major surface (170), fulfilA1 / A2 < 0.3, andA3 / A4< 0.3.
9. The LED filament luminaire according to any one of the preceding claims, wherein the board carrier (130) hasa thickness, T, in a range of 0.2-2 mm,a length, L, in a range of 40-150 mm, anda width, W, in a range of 10-100 mm.
10. The LED filament luminaire according to any one of the preceding claims, further comprisingelectrical tracks (300a, 300b) connected to the plurality of LEDs (200) and provided at least partly on the first major surface (160), andelectrodes (310a, 310b) connected to the electrical tracks (300a, 300b) and extending on the first major surface (160).
11. The LED filament luminaire according to any of the preceding claims, wherein the holder (510) comprises at least one of2025PF8024921a clamping mechanism (520) arranged to clamp the third peripheral portion (320), anda groove (530) arranged to form-fittingly hold the third peripheral portion (320).
12. The LED filament luminaire according to any of the preceding claims, wherein the holder (510) comprises a heat sink (600) configured to dissipate heat from the plurality of LEDs (200) during operation.
13. The LED filament luminaire according to claim 10 and to any one of claims 1-9 and 11-12,wherein the electrodes (310a, 310b) are arranged on the third peripheral portion (320) of the board carrier (130) and on the first major surface (160) of the board carrier (130), andwherein the holder (510) comprises electrical contacts (700a, 700b) arranged to come in electrical contact with the electrodes (310a, 310b) when holding the LED filament arrangement (120).
14. The LED filament luminaire according to any one of the preceding claims, wherein(i) the board carrier (130) extends perpendicular to the light exit window (400),(ii) the elongated encapsulant (220) is arranged in an optical center, OA, of the collimator (300), and(iii) the collimator (300) is a tapered reflector.