WO2016128427A1

WO2016128427A1 - Lighting module and lighting device comprising a lighting module.

Info

Publication number: WO2016128427A1
Application number: PCT/EP2016/052768
Authority: WO
Inventors: Hendrik Jan Eggink; Sébastien Paul René LIBON; Ties Van Bommel
Original assignee: Philips Lighting Holding B.V.
Priority date: 2015-02-12
Filing date: 2016-02-10
Publication date: 2016-08-18

Abstract

A lighting module (100) is disclosed, comprising an elongated member (110) having a light-guiding region (114) within the elongated member (110), wherein the elongated member (110) permits passage of fluid, e.g. a gas such as air, therethrough. The lighting module (100) comprises at least one light-emitting element (120) arranged within the elongated member (110). The lighting module (100) comprises at least one reflector (130) arranged at an end (116, 118) of the elongated member (110) so as to reflect at least a portion of light at the end (116, 118) back into the light-guiding region (114), towards another end (116, 118) where light can be out-coupled from the light-guiding region (114), wherein the at least one reflector (130) is configured with respect to the elongated member (110), or vice versa, so as to permit passage of fluid into or out of the light-guiding region (114). A lighting device (200) comprising the lighting module (100) is also disclosed.

Description

Lighting module and lighting device comprising a lighting module

TECHNICAL FIELD

The present invention generally relates to the field of lighting equipment and devices. Specifically, the present invention relates to a lighting module for use in a lighting device.

BACKGROUND

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, reduced power consumption, an increased efficiency related to the ratio between light energy and heat energy, etc. Solid state based light sources such as LED based light sources may have different optical characteristics compared to incandescent light sources. In particular, solid state based light sources may provide a more directed light distribution and a higher (i.e. cooler) color temperature compared to incandescent light sources. Therefore, efforts have been made in order to make solid state based lighting devices mimic or resemble traditional incandescent lighting devices, e.g. with respect to light distribution and/or color temperature. In bulb lighting devices based on LEDs, commonly referred to as "retrofit lamps" since these LED lamps are often designed to have the appearance of a traditional incandescent light bulb and to be mounted in conventional sockets, etc., the light emitting filament wire is replaced with one or more LEDs. The atmosphere within the bulb is generally air. However, cooling of the LEDs may pose a problem in LED based retrofit lamps. Overheating of LEDs can lead to reduced lifetime, decreased light output or failure of the LEDs.

SUMMARY

In one lighting device architecture for realizing a LED bulb or retrofit lamp, the LEDs are mounted onto the outside of a tubular carrier with open ends which tubular carrier is arranged within a bulb for example made of glass or ceramic. Such a tubular carrier may generally be referred to as an elongated hollow structure having one or more open ends, which structure for example may be cylindrical, conical, truncated conical, funnel-shaped, etc., and may for example have a circular, triangular, rectangular, etc., cross-section. The tubular carrier provides functionality similar to that of a chimney, allowing a fluid (e.g. gas) flow through the tubular carrier, thereby facilitating cooling of the tubular carrier and the LEDs by way of convection taking place within the 'chimney' (i.e. heat generated by the LEDs is transferred to fluid within the tubular carrier, thereby creating a convection flow of fluid within and through the tubular carrier) and by way of thermal radiation emitted from surfaces of the tubular carrier. Although such a chimney configuration or architecture may provide a relatively high efficiency of heat transport away from the LEDs, it may not be able to realize a uniform light intensity distribution from the LED bulb or retrofit lamp which resembles a traditional incandescent light bulb. For example, a LED bulb or retrofit lamp based on such a chimney configuration or architecture may exhibit a region on the outer surface of the bulb, corresponding to a relatively low intensity of light. Such a 'dark' region may be visible to a viewer, which may be undesired.

In view of the above, a concern of the present invention is to provide a lighting module or lighting device which allows for achieving a more uniform distribution of intensity of light emitted by the lighting module or lighting device as compared to utilizing a chimney configuration or architecture as described in the foregoing.

A further concern of the present invention is to provide a lighting module or lighting device which allows for achieving an efficiency of heat transport away from light- emitting elements in the lighting module or lighting device comparable to that of a chimney configuration or architecture as described in the foregoing or even higher.

To address at least one of these concerns and other concerns, a lighting module in accordance with the independent claim is provided. Preferred embodiments are defined by the dependent claims.

According to a first aspect, there is provided a lighting module comprising an elongated member having an inner surface at least in part delimiting, or defining, a light- guiding region within the elongated member. The elongated member has a first end a second end. The light-guiding region permits passage of fluid therethrough and into and out of the first end and the second end, respectively. The lighting module comprises at least one light- emitting element configured to emit light and arranged within the elongated member so as to emit at least some of the light into the light-guiding region. The lighting module comprises at least one reflector arranged at one of the first end and the second end so as to reflect at least a portion of light at the respective one of the first end and the second end back into the light- guiding region, towards the other one of the first end and the second end, wherein light can be out-coupled from the light-guiding region at least via the other one of the first end and the second end. The at least one reflector is configured with respect to the elongated member, or vice versa, so as to permit passage of fluid into or out of the light-guiding region.

By the elongated member being configured such that the light-guiding region within the elongated member permits passage of fluid therethrough, and into and out of the first end and the second end, respectively, flow of circulation of fluid, e.g. a gas such as air or helium, or a mixture of gases including for example air and/or helium, through the light- guiding region, and hence through the elongated member, is facilitated or enabled. Thus, the elongated member may provide functionality similar to that of a chimney, facilitating or allowing for heat transport by way of convection to take place within the elongated member in addition to thermal radiation emitted from surfaces of the elongated member. Thereby, a relatively high degree of cooling of the light-emitting elements, which are arranged within the elongated member, may be achieved.

By means of the at least one reflector, light emitted by the at least one light- emitting element can be reflected at one of the first end and the second end of the elongated member towards the other end of the elongated member, via which other end light can be out-coupled from the light-guiding region, and hence from the lighting module. Thereby, by means of the at least one reflector, light output from the end of the elongated member at which the at least one reflector is not arranged may be increased (as compared to if the at least one reflector would be omitted). At the same time, by means of the at least one reflector being configured with respect to the elongated member, or vice versa, so as to permit passage of fluid into or out of the light-guiding region, the above-mentioned chimney functionality may be maintained, thereby facilitating or allowing for heat transport by way of convection to take place within the elongated member.

As will be discussed further in the following, a lighting module according to the first aspect may be included in a lighting device comprising a light-transmissive envelope at least in part enclosing the lighting module. The light-transmissive envelope may at least in part define a fluidly sealed and enclosed space within which the lighting module is arranged, and which space may include or be filled with a thermally conductive fluid, for example a gas such as air or a gas including helium and/or oxygen or any other gas or mixture of gases. The lighting device may for example be included in or constitute a LED bulb or retrofit lamp which is connectable to a lamp or luminaire socket by way of some appropriate connector, for example an Edison screw base, a bayonet fitting, or another type of connection suitable for the lamp or luminaire known in the art. By means of the lighting module according to the first aspect, an increased uniformity in light emission, e.g., with respect to light intensity and/or brightness, around the lighting module may be achieved. There may be further light-emitting element(s) arranged on the outside of the elongated member. For example, the elongated member may have an outer surface configured to couple at least one light-emitting element thereto. By means of the at least one reflector, light output from the end of the elongated member at which the at least one reflector is not arranged may be increased (as compared to if the at least one reflector would be omitted), and may allow for or facilitate achieving the same or substantially the same light emission around the lighting module. In particular, by means of the lighting module according to the first aspect, the region on the outer surface of the light-transmissive envelope towards which said end of the elongated member is directed (i.e. the end of the elongated member at which the at least one reflector is not arranged) may be illuminated to the same or substantially the same extent as other regions on the outer surface of the light- transmissive envelope. Thus, any 'dark' region on the outer surface of the light-transmissive envelope, corresponding to a relatively low intensity of light, such as mentioned in the foregoing, may be reduced or even avoided. At the same time, a relatively high degree of cooling of the light-emitting elements which are arranged within the elongated member may be achieved, by means of the 'chimney' functionality or effect which is provided by the elongated member, thereby facilitating or allowing for heat transport by way of convection to take place within the elongated member.

By the at least one reflector being arranged at one of the first and second ends so as to reflect light at the respective end back into the light-guiding region, it may according to one example mean that the at least one reflector is arranged so as to reflect light that has exited from the elongated member back into the elongated member or light-guiding region. To this end, the at least one reflector may for example be arranged just outside the respective one of the first and second ends.

According to another example, in addition or alternatively, by the at least one reflector being arranged at one of the first and second ends so as to reflect light at the respective end back into the light-guiding region, it may mean that the at least one reflector is arranged so as to reflect light that is close to or about to exit from the elongated member back into the elongated member or light-guiding region. To this end, the at least one reflector may for example be arranged just inside the respective end of the elongated member, possibly within the light-guiding region. The at least one reflector may hence be arranged within the elongated member or outside the elongated member.

According to an example, the elongated member may be hollow. The light- guiding region, or cavity, may for example include or be constituted by open void(s), permitting any fluid or gas such as air to pass through the elongated member.

According to another example, the light-guiding region may include or be constituted by one or more materials which permit passage of fluid through the light-guiding region and at the same time permits propagation or conveyance of light therein, for example along a direction in which the light-guiding region extends. The material may at least in part include a transparent material, allowing light to pass through the material without being scattered.

The inner surface of the elongated member may be specularly or diffusely reflecting, or have surface portions which are specularly and diffusely reflecting,

respectively. For example the inner surface may comprise coating or layer including AI₂O₃, BaS0₄ T1O₂, transparent, anodized Al, and/or some other reflective material. The inner surface of the elongated member may be configured such that it exhibits a reflectivity of more than 80%, or more than 85%, or even more that 90%.

Different configurations of the at least one reflector, or configurations of the at least one reflector with respect to the elongated member, or vice versa, so as to permit passage of fluid into or out of the light-guiding region, are possible.

For example, the at least one reflector may include at least one through-hole for permitting passage of fluid through the at least one reflector. The at least one reflector may include a plurality of through-holes. A through-hole may have a diameter of about 3 mm or less, or about 2 mm or less, or about 1 mm or less. A smaller diameter may be preferred since this may allow for more light to be reflected back into the elongated member or light- guiding region.

The lighting module may have a longitudinal axis.

According to another example, the lighting module may comprise at least two reflectors, which are spaced from each other with respect to the longitudinal axis of the lighting module.

Each of the at least two reflectors may be configured such that when seen along the longitudinal axis (e.g., in a plane perpendicular to the longitudinal axis), it extends over a selected portion of the first end or the second end, respectively. The at least two reflectors may be arranged relatively to each other, such that when seen along the longitudinal axis of the lighting module, the at least two reflectors together extend substantially over the entire first end or second end, respectively. Thus, the refiectors may be arranged relatively to each other so as to permit passage of fluid into or out of the light- guiding region while at the same time allowing for or facilitating reflecting a substantial portion or even substantially all light at the one of the first end and the second end at which the reflectors are arranged back into the light-guiding region, towards the other one of the first end and the second end.

According to another example, each of the at least two refiectors includes at least one through-hole for permitting passage of fluid through the reflector. The through- holes may be arranged in a staggered fashion such that there is no alignment of through-holes in adjacently arranged reflectors when seen along the longitudinal axis. For example, the through-holes may be arranged in a staggered fashion such that there is no, or substantially no, overlap between through-holes in adjacently arranged refiectors when seen along the longitudinal axis. Thus, the through-holes may be arranged so as to permit passage of fluid into or out of the light-guiding region while at the same time allowing for or facilitating reflecting a substantial portion or even substantially all of the light at the one of the first end and the second end at which the reflectors are arranged back into the light-guiding region, towards the other one of the first end and the second end.

The at least one reflector may for example be plate-like, or planar.

The at least one reflector may be arranged substantially perpendicular to the longitudinal axis of the lighting module.

The at least one reflector may comprise a plurality of reflective segments. Between at least some of the segments there may be a separation and/or some element permitting flow of fluid between the segments.

Each of the plurality of reflective segments may be arranged at an angle to the longitudinal axis of the lighting module. The segments may be arranged at the same or substantially the same angle to the longitudinal axis of the lighting module, or at different angle to the longitudinal axis of the lighting module. Some segments may be arranged at an angle to the longitudinal axis of the lighting module different from an angle to the longitudinal axis of the lighting module at which other segments are arranged. The angle to the longitudinal axis of the lighting module of each of the plurality of reflective segments may be selected so as to facilitate or enable light being reflected at the at least one reflector to travel or be conveyed to the other end of the elongated member without or substantially without undergoing further reflection within the elongated member or with relatively small amount of reflection within the elongated member.

According to an example, the elongated member is not directly connected to the at least one reflector. As will be described further in the following, the elongated member may be indirectly connected to the at least one reflector, e.g. via one or more intermediate components or elements.

According to another example, the elongated member may be (possibly directly) connected to the at least one reflector. The elongated member may be configured with respect to the elongated member, or vice versa, such that there is at least one intervening space between the at least one reflector and the elongated member, so as to permit passage of fluid into or out of the first end or the second end, respectively. Hence, at least one intervening space may be provided between the at least one reflector and the elongated member, such as to permit passage of fluid into or out of the first end or the second end, respectively. The intervening space may for example include a cutout in the elongated member and/or in the at least one reflector.

The at least one light-emitting element arranged within the elongated member may be coupled or connected to the inner surface.

For example, the elongated member may include, or be constituted by, a carrier, or substrate, which may be configured to couple the at least one light-emitting element thereto and/or support the at least one light-emitting element. The carrier may for example comprise at least one insulated metal substrate (IMS), a ceramic substrate, a printed circuit board (PCB) and/or a foil, or an assembly of one or more of such circuits with another part or foil used for thermal management and/or reflection. It can also be part of the elongated member, bent at a certain angle. The carrier may be at least in part flexible (i.e. at least a portion or portions of the carrier may be flexible). For example, the carrier may include a flexible PCB and/or a flexible foil. The carrier may be configured to transfer heat, generated by the at least one light-emitting element when in use, away from the at least one light-emitting element. Thus the carrier may be configured so as to exhibit a heat transferring capacity and/or functionality.

According to one or more embodiments of the present invention, the carrier may be at least in part flexible, and the inner surface of the elongated member may comprise a portion of the carrier which has been folded over another portion of the carrier. By way of the inner surface of the elongated member comprising a portion of the carrier which has been bent or folded over another portion of the carrier, the need for a carrier which is configured so as to permit coupling of light-emitting element(s) thereto on both of two oppositely arranged sides may be reduced or even avoided. Thus, one or more light-emitting elements may be arranged on or coupled to a portion, e.g. an end portion, of one side of a carrier. The carrier may be bent and the portion may be folded over another portion of the carrier such that the one or more light-emitting elements end up on an inner surface of the elongated member, i.e. within the elongated member. The portion of the carrier that has been folded over the other portion of the carrier may or may not be in contact with the other portion of the carrier. Another way to describe such a configuration is that the carrier may have a first side and a second side, opposite to the first side, wherein one or more light-emitting elements are coupled to the first side of the carrier. The carrier is bent and a first portion of the carrier is folded over a second portion of the carrier such that the second side of the first portion of the carrier at least partially faces the second side of the second portion of the carrier, or vice versa, such that the first side of the first portion of the carrier at least in part constitutes the inner surface of the elongated member.

According to one or more embodiments of the present invention, the elongated member and the at least one reflector may be integrally arranged with respect to each other. Thus, the elongated member and the at least one reflector may be formed as one unit. This may for example be realized by way of the elongated member including or being constituted by a carrier, the carrier being at least in part flexible, and with the at least one reflector at least partially being formed by way of bending of a portion of the carrier (e.g., an edge portion) appropriately. The bent portion of the carrier, which hence may at least in part constitute the at least one reflector, may for example be provided with a reflective coating or layer, or it may be refiective in itself.

The elongated member may have an outer surface, which may be configured to couple at least one light-emitting element thereto. Thus, one or more light-emitting elements may be arranged on the outside of the elongated member.

As indicated in the foregoing, a lighting module according to the first aspect is suitable for use for example in lighting devices which may have a light-transmissive envelope at least in part enclosing the lighting module, e.g. in the form of a light bulb, with the lighting module being arranged within the light bulb or light-transmissive envelope.

According to a second aspect, there is provided a lighting device comprising a lighting module according to the first aspect. The lighting device may comprise a light- transmissive envelope at least in part enclosing the lighting module. The light-transmissive envelope may at least in part define a fluidly sealed and enclosed space within which the lighting module is arranged, and which space may include or be filled with a thermally conductive fluid, for example a gas such as air or a gas including helium and/or hydrogen, or a mixture of gases including for example helium, oxygen and/or air. The light-transmissive material of the light-transmissive envelope may be transparent or translucent. The light-transmissive envelope may include at least one portion that is transparent and at least one portion that is translucent.

The lighting device may comprise a base for connection to a lamp socket. The base may include or be constituted by any suitable type of connector, for example an Edison screw base, a bayonet fitting, or another type of connection.

As known in the art, the lighting module and/or the lighting device may include circuitry capable of converting electricity from a power supply to electricity suitable to operate or drive the at least one light-emitting element. The circuitry may be capable of at least converting between Alternating Current and Direct Current and converting voltage into a suitable voltage for operating or driving the at least one light-emitting element.

As known in the art, the lighting module and/or the lighting device may also include other electrical and electronic functionalities. Examples of such are, protection circuits, color regulation circuits, diming circuits, cut-off circuits, monitoring and

temperature limiting circuits, communication circuits (wired and/or wireless) to control the lighting device or lamp or provide any other functionality like for example coded light.

The at least one light-emitting element may for example include or be constituted by a solid state light emitter. Examples of solid state light emitters include LEDs, OLEDs, and laser diodes. Solid state light emitters are relatively cost efficient light sources since they in general are relatively inexpensive and have a relatively high optical efficiency and a relatively long lifetime. However, in the context of the present application, the term "light-emitting element" should be understood to mean substantially any device or element that is capable of emitting radiation in any region or combination of regions of the electromagnetic spectrum, for example the visible region, the infrared region, and/or the ultraviolet region, when activated e.g. by applying a potential difference across it or passing a current through it. Therefore a light-emitting element can have monochromatic, quasi- monochromatic, polychromatic or broadband spectral emission characteristics. Examples of light-emitting elements include semiconductor, organic, or polymer/polymeric LEDs, violet LEDs, blue LEDs, optically pumped phosphor coated LEDs, optically pumped nano-crystal LEDs or any other similar devices as would be readily understood by a person skilled in the art. Furthermore, the term light-emitting element can, according to one or more embodiments of the present invention, mean a combination of the specific light-emitting element or light- emitting elements which emit the radiation in combination with a housing or package within which the specific light-emitting element or light-emitting elements are positioned or arranged. For example, the term light-emitting element can encompass a bare LED die arranged in a housing, which may be referred to as a LED package.

Further objects and advantages of the present invention are described in the following by means of exemplifying embodiments. It is noted that the present invention relates to all possible combinations of features recited in the claims. Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the description herein. Those skilled in the art realize that different features of the present invention can be combined to create embodiments other than those described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplifying embodiments of the present invention will be described below with reference to the accompanying drawings.

Fig. 1 is a schematic cross-sectional side view of a lighting device according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional side view of a lighting module according to an embodiment of the present invention.

Fig. 3 is a schematic top view of the lighting module illustrated in Figure 2.

Fig. 4 is a schematic cross-sectional side view of a lighting module according to an embodiment of the present invention.

Fig. 5 is a schematic cross-sectional side view of a lighting module according to an embodiment of the present invention.

Fig. 6 is a schematic top view of the lighting module illustrated in Figure 5.

Fig. 7 is a schematic cross-sectional side view of a lighting module according to an embodiment of the present invention.

Fig. 8 is a schematic top view of a lighting module according to an

embodiment of the present invention.

Fig. 9 is a schematic cross-sectional side view of a lighting module according to an embodiment of the present invention.

Fig. 10 is a schematic top view of the lighting module illustrated in Figure 9. Fig. 11 is a schematic cross-sectional side view of a lighting module according to an embodiment of the present invention.

Fig. 12 is a schematic top view of a lighting module according to an embodiment of the present invention.

Figs. 13 and 14 are schematic cross-sectional side views of lighting modules according to embodiments of the present invention.

Fig. 15 is a schematic cross-sectional side view of a lighting module according to an embodiment of the present invention.

Fig. 16 is a schematic top view of the lighting module illustrated in Figure 15.

Fig. 17 is a schematic view of the lighting module illustrated in Figures 15 and

16.

Figs. 18 and 19 are schematic cross-sectional side views of lighting modules according to embodiments of the present invention.

All the figures are schematic, not necessarily to scale, and generally only show parts which are necessary in order to elucidate embodiments of the present invention, wherein other parts may be omitted or merely suggested.

DETAILED DESCRIPTION

The present invention will now be described hereinafter with reference to the accompanying drawings, in which exemplifying embodiments of the present invention are illustrated. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will convey the scope of the invention to those skilled in the art.

In the drawings, identical reference numerals denote the same or similar components having a same or similar function, unless specifically stated otherwise.

Figure 1 is a schematic cross-sectional side view of a lighting device 200 according to an embodiment of the present invention. The lighting device 200 comprises a lighting module 100 and a light-transmissive envelope 210 which encloses the lighting module 100.

In accordance with the embodiment of the present invention illustrated in Figure 1, the light-transmissive envelope 210 is bulb-shaped. However, the bulb-shape of the light-transmissive envelope 210 depicted in Figure 1 is according to an example. Other shapes of the light-transmissive envelope 210 are possible, and the light-transmissive envelope 210 may in principle have any shape. The light-transmissive envelope 210 may at least in part define an enclosed space 220 within which the lighting module 100 is arranged. The light-transmissive envelope 210 may be configured such that the space 220 is a fluidly sealed space, and which space may include or be filled for example with air or a thermally conductive fluid, for example a gas including helium and/or hydrogen, or a mixture of gases including for example helium, oxygen and/or air. In accordance with the embodiment of the present invention illustrated in Figure 1, the lighting device 200 may comprise a base 230 for connection to a lamp or luminaire socket (not shown in Figure 1). The base 230 may include or be constituted by any suitable type of coupler or connector, for example an Edison screw base, a bayonet fitting, or any other type of connection which may be suitable for the particular type of lamp or luminaire.

The lighting module 100 comprises an elongated member 110 having an inner surface 112 which at least in part defines, or delimits, a light-guiding region 114 within the elongated member 110. The elongated member 110 has a first end 116 a second end 118. The elongated member 110 is configured such that the light-guiding region 114 permits passage of fluid through the light-guiding region 114, and into and out of the first end 116 and the second end 118, respectively. To that end, according to an example, the elongated member 110 may be hollow, such that the light-guiding region 114 or cavity includes or is constituted by an open void, as illustrated in Figure 1, thereby permitting any fluid or gas such as air, helium, or oxygen, or a mixture of gases including for example helium, oxygen and/or air, to pass through the elongated member 110. However, it is not necessary for the elongated member 110 to be hollow. According to another example (not shown in Figure 1), the light- guiding region 1 14 may include or be constituted by a structure and/or one or more materials which permit passage of fluid through the light-guiding region 114 while at the same time permitting propagation or conveyance of light in the light-guiding region 114. The one or more materials of the light-guiding region 1 14 may at least in part include a transparent material, allowing light to pass through the material (substantially) without being scattered. The one or more materials of the light-guiding region 114 could for example include a porous material, i.e. a material containing pores, or voids.

By the elongated member 110 being configured such that the light-guiding region 114 within the elongated member 110 permits passage of fluid through the elongated member 110 and into and out of the first end 116 and the second end 118, respectively, flow of circulation of fluid, e.g. a gas such as air or helium, through the light-guiding region 114, and hence through the elongated member 110, may be facilitated or even enabled. Thereby the elongated member 110 may provide functionality similar to that of a chimney, facilitating or allowing for heat transport by way of convection to take place within the elongated member 110 by a continuous circulation of fluid through the light-guiding region 114, and hence through the elongated member 110.

The lighting module 100 comprises light-emitting elements 120 configured to emit light and arranged within the elongated member 110 so as to emit at least some of the light into the light-guiding region 114.

In accordance with the embodiment of the present invention illustrated in Figure 1, the lighting module 100 further comprises light-emitting elements 122 configured to emit light and arranged on the outside of the elongated member 110. For example, the light-emitting elements 122 arranged on the outside of the elongated member 110 may be coupled to an outer surface 113 of the elongated member 110, which may be configured to couple the light-emitting elements 122 thereto.

Any one of the light-emitting elements 120, 122 may for example comprise a LED. The number of light-emitting elements 120 within the elongated member 110 and the number of light-emitting elements 122 on the outside of the elongated member 110 are both according to an example. There may in principle be any number of light-emitting elements 120 within the elongated member 110 and any number of light-emitting elements 122 on the outside of the elongated member 110. According to an example, the ratio between the number of light-emitting elements 120 within the elongated member 110 and the number of light-emitting elements 122 on the outside of the elongated member 110 (or the so called epi surface) is 1 :2, or 1 :3. For example, there may be six light-emitting elements 122 on the outside of the elongated member 110 and two light-emitting elements 120 within the elongated member 110.

The lighting module 100 comprises a reflector 130 arranged at the first end

116 so as to reflect at least a portion of light at the first end 116 back into the light-guiding region 114, towards the second end 118, wherein light can be out-coupled from the light- guiding region 114 at least via the second end 118. In accordance with the embodiment of the present invention illustrated in Figure 1 , light can be out-coupled from the light-guiding region 114 also via the first end 116 (albeit to a lesser extent than via the second end 118, as illustrated in Figure 1). The reflector 130 is configured with respect to the elongated member 110, or vice versa, so as to permit passage of fluid into or out of the light-guiding region 114. In accordance with the embodiment of the present invention illustrated in Figure 1 , the reflector 130 may for example be arranged just outside the first end 116 of the elongated member 110, but without being in direct contact with the elongated member 110, so as to reflect light that has exited from the elongated member 110 back into the elongated member 110 or light-guiding region 114. This is however according to an example and variations are possible, for example such as illustrated in Figure 4.

With further reference to Figure 1, by means of the reflector 130, light emitted by the light-emitting elements 120 can be reflected at the first end 116 of the elongated member 110 towards the second end 118 of the elongated member 110, via which second end light 118 can be out-coupled from the light-guiding region 114, and hence from the elongated member 110 and the lighting module 100. Thereby, by means of the reflector 130, light output from the second end 118 of the elongated member 110 may be increased (as compared to if the reflector 130 would be omitted). At the same time, by means of the reflector 130 being configured with respect to the elongated member 110, or vice versa, so as to permit passage of fluid into or out of the light-guiding region 114, a chimney functionality can be maintained, thereby facilitating or allowing for heat transport by way of convection to take place within the elongated member 110.

There may be a support structure which supports the lighting module 100 in the lighting device 200.

In accordance with the embodiment of the present invention illustrated in Figure 1, the support structure comprises a stem or cylindrical support 141 or the like connected to and/or supported by the base 230. The stem 141 may extend for example along a longitudinal axis of the elongated member 110 and into the elongated member 110 via the first end 116. There may be support rods 142 or the like, possibly extending laterally from the stem 141 within the elongated member 110, and being coupled to the inner surface 112 of the elongated member 110.

In accordance with the embodiment of the present invention illustrated in

Figure 1, the reflector 130 is mechanically connected to the stem 141. This is however according to an example and variations are possible, as will be described in the following with reference to the other figures, e.g. with reference to Figure 2.

As known in the art, the lighting device 200 may include circuitry capable of converting electricity from a power supply to electricity suitable to operate or drive the plurality of light-emitting elements 120 and/or power any other electrical components that may be included in the lighting device 200. Such circuitry, which is not shown in Figure 1, may be capable of at least converting between Alternating Current and Direct Current and converting voltage into a suitable voltage for operating or driving the plurality of light- emitting elements 120.

Figure 2 is a schematic cross-sectional side view of a lighting module 100 according to an embodiment of the present invention. Figure 3 is a schematic top view of the lighting module 100 illustrated in Figure 2. The lighting module 100 illustrated in Figure 2 differs from the lighting module 100 illustrated in Figure 1 in that the reflector 130 is not mechanically connected to the stem 141. Instead, the reflector 130 of the lighting module 100 illustrated in Figure 2 is supported by holders e.g. in the form of reflector support rods 143 (of which only a portion is shown in Figure 2). The reflector support rods 143 may for example be connected to and/or supported by the base 230.

As seen in Figure 3, the elongated member 110 has the shape of a hexagon when seen from above. The elongated member 110 may hence have a shape of a hexagonal prism. It is to be understood that this shape is according to an example and that other shapes are possible. For example, the elongated member 110 may have an octagonal or a cylindrical shape, or any other prismatic shape.

Figure 4 is a schematic cross-sectional side view of a lighting module 100 according to an embodiment of the present invention. The lighting module 100 illustrated in Figure 1 is similar to the lighting module 100 illustrated in Figure 2, but differs from the lighting module 100 illustrated in Figure 2 in that the reflector 130 is arranged just inside the first end 116 of the elongated member 110. Thereby, the reflector 130 is arranged so as to reflect light that is close to or about to exit from the elongated member 110 via the first end 116 back into the elongated member 110 or light-guiding region 114.

Figure 5 is a schematic cross-sectional side view of a lighting module 100 according to an embodiment of the present invention. The lighting module 100 illustrated in Figure 5 is similar to the lighting modules 100 illustrated in Figures 1, 2 and 4, but differs from the lighting modules 100 illustrated in Figures 1, 2 and 4 in that the support rods 142 are coupled to reflector 130. The reflector 130 of the lighting module 100 illustrated in Figure 5 is mechanically connected to the stem 141. Figure 6 is a schematic top view of the lighting module illustrated in Figure 5. Thus, the reflector 130 may be a part or portion of a support structure which supports the lighting module 100 in a lighting device 200 (cf. Figure 1). It is to be understood that Figures 5 and 6 illustrate one example of a configuration in which the reflector 130 is a part or portion of a support structure which supports the lighting module 100 in a lighting device 200, and that other configurations are possible. Figure 7 is a schematic cross-sectional side view of a lighting module 100 according to an embodiment of the present invention. The lighting module 100 illustrated in Figure 7 is similar to the lighting module 100 illustrated in Figure 1. The lighting module 100 illustrated in Figure 7 differs from the lighting module 100 illustrated in Figure 1 in that the lighting module 100 illustrated in Figure 7 has a reflector 130 which includes a plurality of through-holes 135 for permitting passage of fluid through the reflector 130.

Figure 8 is a schematic top view of a lighting module 100 according to an embodiment of the present invention, which is similar to the lighting module 100 illustrated in Figure 7 but differs from the lighting module 100 illustrated in Figure 7 in that the reflector 130 includes a larger number of through-holes 135. Only some of the through-holes 135 shown in Figure 8 are indicated by reference numerals.

It is to be understood that the number of through-holes 135 in Figures 7 and 8 are according to examples. The reflector 130 may include less or more through-holes than illustrated in Figures 7 and 8, such as a single through- hole or three, four, five, six, seven or ten or more through-holes.

It is to be understood that the sizes of the through-holes 135 in Figures 7 and 8 are according to examples. The reflector 130 may include (much) larger or (much) smaller through-holes than illustrated in Figures 7 and 8. For example, the reflector 130 may include a through-hole close to a size of the first end 116 of the elongated member 110. According to another example, the reflector 130 may include one or more through-holes having a diameter of a few millimeters, or 1 mm or less.

Figure 9 is a schematic cross-sectional side view of a lighting module 100 according to an embodiment of the present invention. The lighting module 100 comprises two reflectors 130, 131 spaced from each other with respect to a longitudinal axis LA of the lighting module 100. Each of the two reflectors 130, 131 is configured such that when seen along the longitudinal axis LA, the respective reflector 130, 131 extends over a selected portion of the first end 116 of the elongated member 110. The two reflectors 130, 131 are arranged relatively to each other such that when seen along the longitudinal axis LA they together extend over or substantially over the entire first end 116 of the elongated member 110, which can be seen in Figure 10, which is a schematic top view along the longitudinal axis LA of the lighting module 100 illustrated in Figure 9. As can be seen in Figure 10, when seen along the longitudinal axis LA, from above of the lighting module 100, the two reflectors 130, 131 together extend substantially over the entire first end 116 of the elongated member 110. By the two reflectors 130, 131 together extending "substantially" over the entire first end 116 of the elongated member 110 it is meant that almost the entire first end 116, e.g. more than 90% or more than 95%, or even the entire first end 116 of the elongated member 110 is covered by the reflectors 130, 131 when seen along the longitudinal axis LA, from above of the lighting module 100. It is to be understood that the lighting module 100 may include more than two reflectors.

Although the reflectors 130, 131 illustrated in Figures 9 and 10 are plate-like, or planar, it is to be understood that any of the reflectors 130, 131 may be non-planar and instead for example have a curved shape. A reflector in accordance with any other embodiment of the present invention, e.g. such as described with reference to any one of Figures 1-8 and 11-19, may be plate-like or planar, or have another shape, e.g., a curved shape.

Figure 11 is a schematic cross-sectional side view of a lighting module 100 according to an embodiment of the present invention. The lighting module 100 comprises two reflectors 130, 131 spaced from each other with respect to a longitudinal axis LA of the lighting module 100. The reflectors 130, 131 include through-holes 136, 137, respectively, for permitting passage of fluid through the respective reflector 130, 131. As illustrated in Figure 11, the through-holes 136, 137 are arranged in a staggered fashion such that there is no or substantially no alignment of through-holes 136, 137 in the reflectors 130, 131 when seen along the longitudinal axis LA, and even such that there is no or substantially no overlap between through-holes 136, 137 in the reflectors 130, 131 when seen along the longitudinal axis LA.

It is to be understood that the lighting module 100 may include more than two reflectors spaced from each other with respect to the longitudinal axis LA of the lighting module 100, and where each reflector includes at least one through-hole. The through-holes may be arranged in a staggered fashion such that there is no or substantially no alignment of through-holes in adjacently arranged reflectors when seen along the longitudinal axis LA, and possibly even such that there is no or substantially no overlap between through-holes in adjacently arranged reflectors when seen along the longitudinal axis LA.

Figure 12 is a schematic top view of a lighting module 100 according to an embodiment of the present invention, which is similar to the lighting module 100 illustrated in Figure 11 but differs from the lighting module 100 illustrated in Figure 11 in that the reflector 130 includes a larger number of through-holes 136. Only some of the through-holes 136 shown in Figure 12 are indicated by reference numerals. It is to be understood that the sizes of the through-holes 136, 137 in Figures 11 and 12 are according to examples. Any one of the reflectors 130, 131 may include (much) larger or (much) smaller through-holes than illustrated in Figures 11 and 12.

Figure 13 is a schematic cross-sectional side view of a lighting module 100 according to an embodiment of the present invention. The lighting module 100 illustrated in Figure 13 is similar to the lighting module 100 illustrated in Figure 1. The lighting module 100 illustrated in Figure 13 differs from the lighting module 100 illustrated in Figure 1 in that the reflector 130 comprises a plurality of reflective segments 138. According to the embodiment of the present invention illustrated in Figure 13, the reflective segments 138 are arranged (approximately) perpendicular to the longitudinal axis LA.

Figure 14 is a schematic cross-sectional side view of a lighting module 100 according to an embodiment of the present invention. The lighting module 100 illustrated in Figure 14 is similar to the lighting module 100 illustrated in Figure 13. The lighting module 100 illustrated in Figure 14 differs from the lighting module 100 illustrated in Figure 13 in that each of the plurality of reflective segments 138 is arranged at an angle to the longitudinal axis LA of the lighting module 100 different from (approximately) 90 °. The angle to the longitudinal axis LA of the lighting module 100 of each of the plurality of reflective segments 138 may be selected so as to facilitate or enable light being reflected at the reflector 130 to travel or be conveyed to the second end 118 of the elongated member 110 without or substantially without undergoing further reflection within the elongated member 110 or with relatively small amount of reflection within the elongated member 110.

The numbers of reflective segments 138 shown in Figures 13 and 14 are according to examples, and a smaller or a larger number of reflective segments 138 is possible for the lighting module illustrated in Figure 13 and/or 14.

Figure 15 is a schematic cross-sectional side view of a lighting module 100 according to an embodiment of the present invention. Figure 16 is a schematic top view of the lighting module 100 illustrated in Figure 15. Figure 17 is a schematic view of the lighting module 100 illustrated in Figures 15 and 16.

As perhaps best seen in Figure 17, an intervening space 140 may be provided between the reflector 130 and the elongated member 110, such as to permit passage of fluid into or out of the first end 116. According to the embodiment of the present invention illustrated in Figures 15-17, the intervening space 140 is in the form of a cutout in the elongated member 110. As seen in Figure 16, the elongated member 110 has the shape of a hexagon when seen from above, i.e. along the longitudinal axis LA of the lighting module 110. As seen in Figure 17, the elongated member 110 has a shape of a hexagonal prism. It is to be understood that this shape is according to an example and that other shapes are possible. For example, the elongated member 110 may have a cylindrical shape. Although in Figure 17 only one intervening space 140 is shown, in one of the faces of the elongated member 110, there may be more than one intervening space 140 in the elongated member 110 (as indicated in Figure 15), for example one in each face of the elongated member 110, e.g. in the form of a wedge-shaped cutout such as illustrated in Figure 17.

Figure 18 is a schematic cross-sectional side view of a lighting module 100 according to an embodiment of the present invention. The lighting module 100 illustrated in Figure 18 is similar to the lighting module 100 illustrated in Figure 2. In the lighting module 100 illustrated in Figure 18, the elongated member 110 is constituted by a carrier which is at least in part flexible, and wherein the inner surface 112 of the elongated member 110 comprises a portion of the carrier which has been folded over another portion of the carrier, as indicated by the arrow in Figure 18. The carrier may have a first side 117 and a second side 119, opposite to the first side 117, wherein light-emitting elements 121, 122 are coupled to the first side 117 of the carrier. The carrier can then be bent, and a first portion 151 of the carrier folded over a second portion 152 of the carrier, in such a way that the second side 119 of the first portion 151 of the carrier at least partially faces the second side 119 of the second portion 152 of the carrier, or vice versa, as illustrated in Figure 18. The light-emitting elements 121 thereby end up on the inner surface 112 of the elongated member 110, within the elongated member 110. Thereby, the carrier may be configured so as to possibly only allow for coupling of light-emitting element(s) thereto on one side thereof (the first side 117 according to the example illustrated in Figure 18). The need for a carrier which is configured so as to permit coupling of light-emitting element(s) thereto on both the first side 117 and the second side 119 may thus be avoided.

Figure 19 is a schematic cross-sectional side view of a lighting module 100 according to an embodiment of the present invention, illustrating the possibility of the elongated member 110 and the reflector 130 being integrally arranged with respect to each other. In accordance with the embodiment of the present invention illustrated in Figure 19, this may be implemented by way of the elongated member 110 being constituted by a carrier which is at least in part flexible, and with the reflector 130 at least partially being formed by way of bending by a portion of the carrier appropriately (indicated by the arrow in Figure 19). The bent portion of the carrier which faces the light-guiding region 1 14 may be reflective by itself, or it may for example be provided with a reflective coating or layer. Further in accordance with the embodiment of the present invention illustrated in Figure 19, the inner surface 112 of the elongated member 110 comprises a portion of the carrier which has been folded over another portion of the carrier, similarly to the lighting module 100 illustrated in Figure 18. However, such a configuration is optional and may be provided independently from a configuration where the elongated member 110 and the reflector 130 are integrally arranged with respect to each other, or vice versa.

In conclusion, a lighting device is disclosed, comprising an elongated member having a light-guiding region within the elongated member, wherein the elongated member permits passage of fluid, e.g. a gas such as air, therethrough. The lighting module comprises at least one light-emitting element arranged within the elongated member. The lighting module comprises at least one reflector arranged at an end of the elongated member so as to reflect at least a portion of light at the end back into the light-guiding region, towards another end where light can be out-coupled from the light-guiding region, wherein the at least one reflector is configured with respect to the elongated member, or vice versa, so as to permit passage of fluid into or out of the light-guiding region. A lighting device comprising the lighting module is also disclosed.

While the present invention has been illustrated in the appended drawings and the foregoing description, such illustration is to be considered illustrative or exemplifying and not restrictive; the present invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the appended claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS:

1. A lighting module (100) comprising:

an elongated member (110) having an inner surface (112) at least in part delimiting a light-guiding region (114) within the elongated member, wherein the elongated member has a first end (116) a second end (118), and wherein the light-guiding region permits passage of fluid therethrough and into and out of the first end and the second end, respectively; and

at least one light-emitting element (120; 121) configured to emit light and arranged within the elongated member so as to emit at least some of the light into the light- guiding region;

characterized in that the lighting module comprises:

at least two reflectors (130, 131) arranged at one of the first end and the second end so as to reflect at least a portion of light at the respective one of the first end and the second end back into the light-guiding region, towards the other one of the first end and the second end, wherein light can be out-coupled from the light-guiding region at least via the other one of the first end and the second end, wherein the at least two reflectors are configured with respect to the elongated member, or vice versa, so as to permit passage of fluid into or out of the light-guiding region;

wherein the at least two reflectors are spaced from each other with respect to a longitudinal axis (LA) of the lighting module, and wherein the at least two reflectors are separately arranged with respect to the elongated member.

2. A lighting module according to claim 1, wherein at least one of the reflectors include at least one through-hole (135) for permitting passage of fluid through the at least one reflector.

3. A lighting module according to claim 1 or 2, wherein each of the at least two reflectors is configured such that when seen along the longitudinal axis it extends over a selected portion of the first end or the second end, respectively, wherein the at least two reflectors are arranged relatively to each other such that when seen along the longitudinal axis they together extend substantially over the entire first end or second end, respectively.

4. A lighting module according to claim 1 or 2, wherein each reflector includes at least one through-hole (136, 137) for permitting passage of fluid through the reflector, and wherein the through-holes (136, 137) are arranged in a staggered fashion such that there is no alignment of through-holes in adjacently arranged reflectors when seen along the longitudinal axis.

5. A lighting module according to claim 4, wherein the through-holes are arranged in a staggered fashion such that there is no overlap between through-holes in adjacently arranged reflectors when seen along the longitudinal axis.

6. A lighting module according to any one of claims 1-5, wherein at least one of the refiectors is plate-like and arranged substantially perpendicular to a longitudinal axis of the lighting module.

7. A lighting module according to any one of claims 1-5, wherein at least one of the refiectors comprises a plurality of reflective segments, and wherein each of the plurality of reflective segments is arranged at an angle to a longitudinal axis of the lighting module.

8. A lighting module according to any one of claims 1-7, wherein at least one reflector is arranged within the elongated member.

9. A lighting module according to any one of claims 1-7, wherein at least one reflector is arranged outside the elongated member.

10. A lighting module according to any one of claims 1-9, wherein the elongated member is connected to the at least two refiectors, wherein the elongated member is configured with respect to the at least two refiectors, or vice versa, such that there is at least one intervening space (140) between the at least two refiectors and the elongated member so as to permit passage of fluid into or out of the first end or the second end, respectively.

11. A lighting module according to any one of claims 1-10, wherein the elongated member includes a carrier.

12. A lighting module according to claim 11, wherein the carrier is at least in part flexible and wherein the inner surface comprises a portion of the carrier which has been folded over another portion of the carrier.

13. A lighting module according to any one of claims 1-12, wherein the elongated member has an outer surface (113) configured to couple at least one light-emitting element (122) thereto.

14. A lighting device (200) comprising:

a lighting module (100) according to any one of claims 1-13; and a light-transmissive envelope (210) at least in part enclosing the lighting module.