EP4673682A1

EP4673682A1 - Heat spreader fixation

Info

Publication number: EP4673682A1
Application number: EP24706164.1A
Authority: EP
Inventors: Micha Jan HORACZEK; Peter Johannes Martinus BUKKEMS
Original assignee: Signify Holding BV
Current assignee: Signify Holding BV
Priority date: 2023-03-02
Filing date: 2024-02-26
Publication date: 2026-01-07
Also published as: CN120813800A; WO2024179950A1

Abstract

The invention provides a light generating system comprising a lamp module, wherein the lamp module comprises (i) a housing, (ii) a heat spreader, (iii) a light generating device, and (iv) an optical arrangement, wherein: (a) the housing comprises a hollow front section, wherein the hollow front section comprises a housing front opening, wherein the hollow front section has a front section height (H1), wherein the hollow front section tapers over at least part of the front section height (H1) in a direction away from the housing front opening, wherein the hollow front section comprises a hollow front section wall; (b) the heat spreader has a cup-like shape, wherein the heat spreader comprises a heat spreader front opening, wherein the heat spreader has a heat spreader height (H2), wherein the heat spreader tapers over at least part of the heat spreader height (H2) in a direction away from the heat spreader front opening; wherein the heat spreader comprises a heat spreader wall, wherein the heat spreader wall comprises a thermally conductive material; wherein the heat spreader is arranged in the hollow front section, wherein at least part of the heat spreader is configured in thermal contact with at least part of the hollow front section wall (520); (c) the light generating device is configured to generate device light; wherein the light generating device is at least partly configured in the heat spreader, and is configured in thermal contact with the heat spreader; and (d) the optical arrangement comprises an optical element, wherein the optical element is configured downstream of the light generating device; wherein the optical element is transmissive for the device light; wherein the optical arrangement is attached to the hollow front section, and is at least partly configured in the housing front opening.

Description

Heat spreader fixation

FIELD OF THE INVENTION

The invention relates to a light generating system comprising a heat spreader. Further, the invention relates to a lighting device comprising the light generating system. The invention also relates to a method of assembly of the light generating system.

BACKGROUND OF THE INVENTION

Light generating systems comprising a heat spreader are known in the art. US2014055997A1, for instance, describes an LED array which is thermally coupled to a heat spreader and a heatsink.

SUMMARY OF THE INVENTION

Light generating systems comprising one or more spot lamps are popular for various applications. Spot lamps are being used in houses as well as public spaces such as shops and museums to illuminate specific items. Spot lamps may typically have a high power density, so they dissipate a relatively high amount of power (heat) in a relatively small volume. Therefore, construction of spot lamps may need to provide efficient cooling to maintain temperature of electrical components and driver components within allowed limits. Current spot lamps may have a low thermal performance of the housing. Further, current methods of manufacturing spot lamps may have several drawbacks such as investment costs, lead time, cost of the housing, and requirements for post processing.

Hence, it is an aspect of the invention to provide an alternative light generating system, which preferably further at least partly obviates one or more of above-described drawbacks. The present invention may have as object to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

According to a first aspect, the invention provides a light generating system comprising a lamp module. In embodiments, the lamp module may comprise one or more of (i) a housing, (ii) a heat spreader, (iii) a light generating device, and (iv) an optical arrangement. The housing may in embodiments comprise a hollow front section. The hollow front section may in embodiments have a front section height (Hl). In embodiments, the hollow front section may comprise one or more of a housing front opening and a hollow front section wall. The hollow front section may in embodiments taper over at least part of the front section height (Hl) in a direction away from the housing front opening. The heat spreader may in embodiments have a cup-like shape. Further, the heat spreader may have a heat spreader height (H2). In embodiments, the heat spreader may comprise one or more of a heat spreader front opening and a heat spreader wall. In embodiments, the heat spreader may taper over at least part of the heat spreader height (H2) in a direction away from the heat spreader front opening. The heat spreader wall may further comprise a thermally conductive material. In embodiments, the heat spreader may be arranged in the hollow front section (of the housing). At least part of the heat spreader wall may in embodiments be conformal with the hollow front section wall. Especially, at least part of the heat spreader wall may be configured in thermal contact with at least part of the hollow front section wall. The light generating device may in embodiments be configured to generate device light. In embodiments, the light generating device may at least partly be configured in the heat spreader. In further embodiments, the light generating device may be configured in thermal contact with the heat spreader. In embodiments, the optical arrangement may comprise an optical element. The optical element may in embodiments be one or more of configured downstream of the light generating device, transmissive for the device light, attached to the hollow front section, and at least partly configured in the housing front opening. Hence, in specific embodiments, the invention provides a light generating system comprising a lamp module, wherein the lamp module comprises (i) a housing, (ii) a heat spreader, (iii) a light generating device, and (iv) an optical arrangement, wherein: (a) the housing comprises a hollow front section, wherein the hollow front section comprises a housing front opening, wherein the hollow front section has a front section height (Hl), wherein the hollow front section tapers over at least part of the front section height (Hl) in a direction away from the housing front opening, wherein the hollow front section comprises a hollow front section wall; (b) the heat spreader has a cup-like shape, wherein the heat spreader comprises a heat spreader front opening, wherein the heat spreader has a heat spreader height (H2), wherein the heat spreader tapers over at least part of the heat spreader height (H2) in a direction away from the heat spreader front opening; wherein the heat spreader comprises a heat spreader wall, wherein the heat spreader wall comprises a thermally conductive material; wherein the heat spreader is arranged in the hollow front section, wherein at least part of the heat spreader wall is configured in thermal contact with at least part of the hollow front section wall 520); (c) the light generating device is configured to generate device light; wherein the light generating device is at least partly configured in the heat spreader, and is configured in thermal contact with the heat spreader; and (d) the optical arrangement comprises an optical element, wherein the optical element is configured downstream of the light generating device; wherein the optical element is transmissive for the device light; wherein the optical arrangement is attached to the hollow front section, and is at least partly configured in the housing front opening.

With such light generating system, heat produced by the system may be distributed more efficiently. As heat may decrease a lifetime of a light generating system, the present invention may provide an increased lifetime. Further, the invention may increase yield and/or efficiency of the light generating system. Also, the method of manufacturing may be more sustainable as well as require less material. Therefore, the present invention may be cheaper to manufacture. The light generating system of the invention may in embodiments comprise one or more of MR16, GU4, GU10, G4, G5.3, G6.35, G9 and GX5.3 spot lamps. However, in embodiments, the invention may also relate to other types of lamps.

As indicated above, the light generating system may especially comprise a lamp module, wherein the lamp module may comprise one or more of (i) a housing, (ii) a heat spreader, (iii) a light generating device, and (iv) an optical arrangement. These components are described in more detail below.

The housing may in embodiments comprise one or more of a deep drawn housing, a (high pressure die) casted housing, a forged housing, a (injection) molded housing, and a rubber pressed housing. In embodiments, the housing may comprise a hollow front section. Especially, the hollow front section may be a part of the housing. Additionally, the housing may in embodiments comprise a back section. In embodiments, the hollow front section and the back section may be monolithic. In alternative embodiments, the hollow front section and the back section may be separate parts assembled into the housing. In embodiments, the hollow front section may comprise a housing front opening. The hollow front section may have a front section height (Hl). In embodiments, the hollow front section may taper over at least part of the front section height (Hl) in a direction away from the housing front opening. In such embodiments, the hollow front section may in embodiments have hollow front section shape, wherein the hollow front section shape may taper. In embodiments, the hollow front section shape may comprise a conical (frustum) shape, a (spherical) dome shape, a cylindrical shape, or a prismatic shape. However, other shapes (including irregular shapes) are herein not excluded. In embodiments, the hollow front section may comprise a hollow front section wall. In embodiments, the hollow front section wall may have a front section wall thickness wherein the front section wall thickness may be substantially constant. In embodiments, the front wall thickness may be selected from the range of 0.5-5 mm. The hollow front section may in embodiments comprise one or more of the heat spreader and the light generating device (see below). However, it is not excluded that the hollow front section may also comprise further components. Hence, in embodiments a shape of the hollow front section wall may be chosen such, that the hollow front section tapers.

Similar to the housing, the heat spreader may in embodiments comprise a heat spreader front opening. The heat spreader may have a heat spreader height (H2). In embodiments, the heat spreader may taper over at least part of the heat spreader height (H2) in a direction away from the heat spreader front opening. In embodiments, the heat spreader may comprise a heat spreader wall. In embodiments, the heat spreader wall may have a heat spreader wall thickness wherein the heat spreader wall thickness may be substantially constant. In embodiments, the heat spreader wall thickness may be selected from the range of 0.5-5 mm. However, other thicknesses may also be possible. The heat spreader wall may in embodiments comprise a thermally conductive material (see further below). Especially, the heat spreader may in embodiments be arranged in the hollow front section.

The heat spreader may comprise a heat spreader shape. In embodiments, the heat spreader shape may be a cup-like shape. In further embodiments, the heat spreader shape may in embodiments be similar to (at least part of) the hollow front section shape. Hence, in embodiments the heat spreader may have a conical (frustum) shape, a (spherical) dome shape, a cylindrical shape, or a prismatic shape. However, other shapes (including irregular shapes) are herein not excluded. Especially, at least part of the heat spreader wall may in embodiments be conformal with the hollow front section wall. More especially, at least part of the heat spreader wall may in embodiments be configured in thermal contact with at least part of the hollow front section wall. Hence, in embodiments a shape of the heat spreader wall may be chosen such, that the heat spreader tapers.

The light generating device may (in an operational mode of the light generating system) in embodiments be configured to generate device light. In embodiments, the device light may comprise visible light, especially white light. In embodiments, the light generating device may at least partly be configured in the heat spreader, especially on a heat spreader wall or on a heat spreader bottom (such as the bottom of the cup-like shaped heat spreader). The light generating device may in embodiments be configured in thermal contact with the heat spreader. In this way, the heat spreader may (in an operational mode of the light generating system) conduct thermal energy away from the light generating device. In embodiments, the light generating device may comprise a solid-state light source. Especially, the solid-state light source may in embodiments be selected from the group of a COB, a LED, a diode laser, and a superluminescent diode. Hence, in specific embodiments, the light generating device comprises a solid-state light source, wherein the solid-state light source is selected from the group of a COB, a LED, a diode laser, and a superluminescent diode.

The light generating device may be functionally coupled to a printed circuit board (PCB). Functionally coupled may herein refer to one or more of mechanically coupled and electrically coupled. Especially, the PCB may mechanically support and electrically connect electronic components or electrical components using electrically conductive tracks, pads and other features etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate (shortly indicated as “track” or “conductive track”); though other options may also be possible.

A PCB may comprise one or more electrically conductive tracks, which may e.g. comprise copper. When there are two or more electrically conductive tracks, two or more tracks may be electrically isolated from each other. In embodiments, two or more electrically conductive tracks may be electrically isolated from each other but be (temporarily) electrically connected to each other via one or more electrical component. The electrical connection may be temporary, when e.g. during operation a switch opens or closes an electrical connection. An electrical connection may e.g. be permanent, when e.g. an electrical component is configured electrically connected to two electrically conductive tracks.

An (electronic) component, such as a solid stage light source, may generally be soldered onto the PCB to both electrically connect and mechanically fasten it to the PCB. For instance, a basic PCB may consist of a flat sheet of insulating material and a layer of copper foil, laminated to the substrate.

Hence, the shape of a PCB may in general be plate-like. Especially, in embodiments the PCB may have a length and a width and a height, wherein an aspect ratio of the length and the height is at least 5, like in the range of 5-5000, like 10-2500, and wherein an aspect ratio of the width and the height is at least 2, such as an aspect ratio of at least 5, like in the range of 5-5000, like 10-2500. The terms “length”, “width”, and “height” may also refer to “largest length”, “largest width”, and “largest height”, respectively. The PCB may especially have a rectangular cross-section (such as a square cross-section).

The height (or thickness) of the PCB may in embodiments be selected from the range of 0.2-10 mm, such as 0.5-5 mm, like 1-2 mm. The width of the PCB may in embodiments be selected from the range of 5-200 mm, such as 5-50 mm. The length of a single printed circuit board area may in embodiments e.g. be selected from the range of 10- 300 mm, such as 10-100 mm, especially 10-50 mm, such as 15-40 mm. The length of the PCB, including a plurality of (connected) PCBs, may in embodiments e.g. be selected from the range of 20-2000 mm, such as 20-1500 mm. Other dimensions may be possible as well.

In further embodiments, the electronic component may be selected from the group comprising a solid state light source, a driver, an electronic module, or a sensor. Especially, the electronic component may comprise a solid state light source.

Hence, the light generating device may especially comprise a solid state light source. Further, the term “light generating device” may also refer to a plurality of (different) light generating devices.

In embodiments, the board may comprise a rigid board or a semi-rigid board, especially a rigid board. In other embodiments, the board may comprise a semi-rigid board. In specific embodiments, the printed circuit may be flexible. In yet other embodiments, the printed circuit board may be rigid.

In embodiments, the board may comprise a metal, especially a metal selected from the group comprising copper aluminum, tin, iron, silver, and lead, more especially a metal selected from the group comprising copper and aluminum.

In further embodiments, the (printed circuit) board may have a thermal conductivity (in an in-plane direction) of at least 100 W/(m*K), such as least 200 W/(m*K), especially at least 250 W/(m*K), such as at least 300 W/(m*K). Instead of “W/m*K” also the indications W/mK or W.m-l.K-1 may be applied.

In embodiments the printed circuit board comprises a thermally conductive material, such as aluminum. Printed circuit boards comprising a metal core may also be indicated as insulated metal substrate (IMS). The substrate may also be based on highly flexible printed electronics where electronic circuitry is printed on substrates such as PET and polyimide films. More especially, the support may comprise a flexible printed circuits (FPC).

In embodiments, the PCB may be configured in the heat spreader, especially on a heat spreader wall or on a heat spreader bottom (such as the bottom of the cup-like shaped heat spreader). In alternative embodiments, the heat spreader may comprise the PCB (see below).

The optical arrangement may in embodiments comprise an optical element. Especially, the optical element may in embodiments be configured downstream of the light generating device. The optical arrangement may further comprise one or more supporting elements that are configured outside of a beam of device light.

The terms “upstream” and “downstream” relate to an arrangement of items or features relative to the propagation of the light from a light generating means (here the especially the light generating device), wherein relative to a first position within a beam of light from the light generating means, a second position in the beam of light closer to the light generating means is “upstream”, and a third position within the beam of light further away from the light generating means is “downstream”.

In embodiments, the optical element may be transmissive for the device light. In further embodiments, the optical element may be transparent for the device light. Especially, in embodiments at least 80%, more especially at least 90%, such as at least about 95%, of the device light received by the optical element will be transmitted by the optical element (especially hereby not taking reflection into account). At least 98% transmission may also be possible. The percentage may refer to the percentage based on power (Watts) of the device light. The optical element may in embodiments comprise one or more of plastic and glass. In embodiments, the optical arrangement may be attached to the hollow front section and may at least partly be configured in the housing front opening. In embodiments, the optical arrangement may be configured to keep the heat spreader arranged in the hollow front section. In alternative embodiments, the optical element may not be involved to keep the heat spreader arranged in the hollow front section.

In further embodiments, the light generating system may be configured (in an operational mode) to generate system light. Especially, the system light may comprise device light escaped from the hollow front section via the optical arrangement. In embodiments, at least part of the device light may escape from the hollow front section via the optical arrangement.

Returning to the heat spreader, in embodiments, the heat spreader wall may be reflective for the device light. In this way, less device light may be absorbed by (parts of) the lamp module, especially the heat spreader, which may provide more system light. Hence, the light generating system may be more efficient. Reflective may herein refer to reflecting at least 50%, such as at least 70% of the device light under perpendicular irradiation. In specific embodiments, the heat spreader wall may comprise a reflective coating, which may further increase the reflectivity for the device light.

As indicated above, at least part of the heat spreader wall may be conformal with the hollow front section wall. Especially, a shape of the heat spreader wall over at least part of the heat spreader height (H2) may be conformal to a shape of the front section wall. In further embodiments, the heat spreader wall over at least part of the heat spreader height (H2) may be in physical contact with at least part of the front section wall. In this way, the heat spreader may efficiently transfer thermal energy to the hollow front section (wall). Hence, in specific embodiments, the heat spreader wall is reflective for the device light, wherein a shape of the heat spreader wall over at least part of the heat spreader height (H2) is conformal to a shape of the hollow front section wall and in physical contact therewith.

In further embodiments, the heat spreader may comprise an external surface and an internal surface. Especially, the external surface may at least partly be defined by the heat spreader wall. In embodiments, at least 5%, such as at least 10%, like at least 15%, especially at least 20% of a surface area of the external surface may be configured in physical contact with the front section wall. In embodiments, such as wherein the heat spreader has a cylindrical shape, a conical frustum shape, or a prismatic shape, the external surface may also be partly defined by the heat spreader bottom. In embodiments, wherein the heat spreader shape comprises a heat spreader wall and a heat spreader bottom, at least 20%, such as at least 30%, like at least 50%, especially at least 60% of an external surface of the heat spreader wall may be configured in physical contact with the front section wall. Note that the printed circuit board may (thus) in embodiments be configured on the internal surface (see also above).

Returning to the optical arrangement, the optical element may in embodiments comprise a lens. The lens may provide beam shaping of the system light. Especially, the optical element may in embodiments comprise a Fresnel lens. In this way, the light generating system may have a flat outer surface while still providing beam shaping of the system light. Other lenses then a Fresnel lens may also be possible. The optical element may also comprise a plurality of lenses.

The optical arrangement may in embodiments be attached to the hollow front section. Especially, the optical arrangement may in embodiments be attached to the hollow front section via a click connection. The click connection may in embodiments be formed by the hollow front section and the optical element. Especially, the hollow front section may comprise a first feature. The first feature may in embodiments be protruding or recessed relative to the hollow front section. Especially, the first feature may in embodiments be protruding or recessed relative to a remainder of the hollow front section. Herein “remainder of the hollow front section” may in embodiments refer to all of the hollow front section except for the first feature. In embodiments, the first feature may be comprised by the front section wall. Additionally or alternatively, the first feature may in embodiments be functionally coupled to the front section wall. In further embodiments, the optical arrangement may comprise a second feature. The second feature may in embodiments be recessed or protruding relative to the optical arrangement. Especially, the second feature may in embodiments be recessed or protruding relative to a remainder of the optical arrangement. Herein “remainder of the optical arrangement” may in embodiments refer to all of the optical arrangement except for the second feature. In specific embodiments, the first feature may be protruding relative to (the remainder) of the hollow front section and the second feature may be recessed relative to (the remainder) of the optical arrangement. In alternative embodiments, the first feature may be recessed relative to (the remainder) of the hollow front section and the second feature may be protruding relative to (the remainder) of the optical arrangement.

Especially, the first feature and the second feature may in embodiments form the click connection. Hence, in specific embodiments, the hollow front section may comprise a first feature that is, in specific embodiments protruding or recessed relative to the hollow front section, wherein the optical arrangement comprises a second feature that is, in specific embodiments recessed or protruding relative to the optical arrangement, and wherein the first feature and the second feature form the click connection. In this way, the optical arrangement may be “clicked” into the hollow front section.

As indicated above, optical arrangement may in embodiments be attached to the hollow front section. In embodiments, the hollow front section may comprise a front section rim. Especially, the optical arrangement may in embodiments at least partly enclose the front section rim. Hence, in specific embodiments, the hollow front section comprises a front section rim, and the optical arrangement at least partly encloses the front section rim. In this way, the hollow front section may be less visible to an observer. Additionally or alternatively, the optical arrangement may have a larger diameter than the housing front opening, hence the device light may exit the optical arrangement via a surface area larger than the housing front opening.

As indicated above, the first feature may be comprised by the front section wall or may be functionally coupled to the front section wall. In embodiments, the first feature may be functionally coupled to the front section rim. Especially the front section rim may be defined by the front section wall and the first feature. Hence, in specific embodiments, the first feature is functionally coupled to the front section rim. In embodiments, the hollow front section may comprise an inward fold. Especially, the hollow front section wall may in embodiments comprise the inward fold. More especially, the first feature may in embodiments comprise the inward fold.

The inward fold may be a folded hem, a flat hem, an open hem, a rolled hem, a teardrop hem, or a rope hem. However, other shapes of the inward fold may also be possible. In embodiments, the inward fold may comprise a first inward bend having a first angle (ai) relative to a tangential (T) to the front section wall. In embodiments, the first angle (ai) may be selected from the range of 0° to ° to 360°, such as from the range of 0° to ° to 270°, like from the range of 10° to 270°, especially from the range of 10° to 210°. In alternative embodiments, ai>360°. Hence, in specific embodiments, the hollow front section comprises an inward fold, wherein the inward fold comprises a first inward bend having a first angle (ai) relative to a tangential (T) to the front section wall, wherein the first angle (ai) is selected from the range of 0° to 270°, such as at least about 10°, wherein the first feature comprises the inward fold. In this way, the inward fold may form the click connection.

Further, the inward fold may also comprise a second inward bend. The second inward bend may have a second angle (a?) relative to a part of the hollow front part wall between the second angle and the first angle. In embodiments, the second angle (a?) may be selected from the range of 0° to 180°, such as from the range of 0° to 135°, like from the range of 45° to 135°, especially from the range of 60° to 120°.

In further embodiments, the inward fold may comprise more than two inward bends. Each inward bend may in embodiments be separated by a linear section of the hollow front section. In yet further embodiments, the inward fold may comprise a continuous bend.

In embodiments, the first feature, especially the inward fold, may be configured to hold the heat spreader in the hollow front section. The first feature, especially the inward fold, may in embodiments be configured to hold the heat spreader in thermal contact with the hollow front section wall. In further embodiments, the first feature, especially the inward fold, may be configured to hold the optical arrangement configured at least partly in the housing front opening.

The embodiments described above in relation to the inward fold and the first (and second) bend are described from a cross-sectional perspective wherein the cross- sectional plane passes through the optical axis. In the embodiments described here below, the inward fold and the rim are described from a cross-sectional perspective perpendicular to the optical axis. In embodiments, the inward fold may be a continuous fold around a perimeter of the rim. In such embodiments, the rim may comprise a full circle inward fold of 360°. In alternative embodiments, the rim may comprise a plurality of inward folds. In such embodiments, the inward fold may comprise an inward fold circle section. In such embodiments, the inward fold circle section may comprise 1° to 40°, such as 3° to 30°, especially 5° to 25°. In embodiments, the rim may comprise 2-20 inward folds, such as 3-10 inward folds, especially 3-6 inward folds. In such embodiments, the rim may further comprise circle sections without an inward fold.

The housing front opening may in embodiments have a housing front opening diameter (DI). The optical arrangement may have an optical arrangement diameter (D2). In embodiments, DI may be selected from the range of 1 - 20 cm, especially from the range of 3 - 15 cm, such as from the range of 4 - 12 cm. D2 may in embodiments be selected from the range of 1 - 25 cm, especially from the range of 3 -20 cm, such as from the range of 4 - 18 cm. In embodiments, D2>D1. Especially, in embodiments 1.02<D2/Dl<1.5, such as 1.02<D2/Dl<1.2, like 1.05<D2/Dl<1.2. In such embodiments, parts of the optical arrangement outside DI (an “edge” of the optical arrangement) may be considered as supporting elements. The edge of the optical arrangement may be configured outside of the beam of the device light (as the device light may be shielded by the housing wall, especially by the inward fold). However, in embodiments, device light (especially system light) may be internally (in the optical arrangement, especially the optical element) reflected and exit the optical arrangement from the edge. In this way, the optical arrangement may provide beam shaping.

As indicated above, the optical element may in embodiments be transmissive for the device light. Especially, the optical arrangement may in embodiments be transmissive for the device light. More especially, the optical arrangement may in embodiments be transparent for the device light. In such embodiments, the supporting elements may be transmissive for the device light, especially transparent for the device light. Hence, in specific embodiments, the housing front opening has a housing front opening diameter (DI), the optical arrangement has an optical arrangement diameter (D2), wherein D2>D1, wherein the optical arrangement is transmissive for the device light.

Returning to the heat spreader. The heat spreader may in embodiments be manufactured via one or more of deep drawing, casting, high pressure die casting, forging, injection molding, and rubber pressing. Hence, in embodiments, the heat spreader may comprise one or more of a deep drawn heat spreader, a (high pressure die) casted heat spreader, a forged heat spreader, a (injection) molded heat spreader, and a rubber pressed heat spreader. Depending on the method of manufacture, the heat spreader may have slightly different properties and/or appearance, which will be known to a person skilled in the art. Hence, in specific embodiments, the heat spreader comprises a deep drawn heat spreader.

As indicated above, the heat spreader (wall) may in embodiments comprise a thermally conductive material. The heat spreader may in embodiments comprise one or more of aluminum, copper, zinc, steel, stainless steel, and plastic. In embodiments, the heat spreader may comprise aluminum. In such embodiments, the heat spreader may in embodiments have a thermal conductivity selected from the range of 100 - 250 W/mK. In specific embodiments, the heat spreader and the housing may comprise aluminum. In other embodiments, the heat spreader may comprise copper, wherein the heat spreader may have a thermal conductivity selected from the range of 300 - 420 W/mK. In other embodiments, the heat spreader may comprise zinc, wherein the heat spreader may have a thermal conductivity selected from the range of 80 - 150 W/mK. In yet other embodiments, the heat spreader may comprise steel, wherein the heat spreader may have a thermal conductivity selected from the range of 5 - 80 W/mK. In other embodiments, the heat spreader may comprise stainless steel, wherein the heat spreader may have a thermal conductivity selected from the range of 10 - 60 W/mK. In yet other embodiments, the heat spreader may comprise plastic, wherein the heat spreader may have a thermal conductivity selected from the range of 0.1 - 30 W/mK. Hence, in further embodiments, the heat spreader may have a thermal conductivity selected from the range of 0.1-420 W/mK. Hence, in specific embodiments, one or more of the following applies: (i) the heat spreader comprises a deep drawn heat spreader; (ii) the heat spreader comprises one or more of aluminum, copper, zinc, steel, stainless steel and plastic; and (iii) the heat spreader has a thermal conductivity selected from the range of 0.1-420 W/mK, especially at least about 5 W/mK, such as at least about 10 W/mK.

The heat spreader may especially be a thermally conductive element. The heat spreader may be configured to transfer energy as heat from a first element to a second element. The second element may especially be a heatsink or heat exchanger. Here, the hollow front section may function as the second element. Additionally or alternatively, the lamp module may in embodiments comprise a heatsink, see below. A heat spreader may be passive or active. Embodiments of passive heat spreaders may comprise a plate or block of material having high thermal conductivity, such as copper, aluminum, or diamond. An active heat spreader may be configured to speed up heat transfer with expenditure of energy as work supplied by an external source. Herein, the heat spreader may especially be a passive heat spreader. Alternatively or additionally, the heat spreader may be an active heat spreader, such as selected from the group of heat pipes and vapor chambers. A heat spreader especially comprises (more especially consists of) a thermally conductive material. The term “heat spreader” may also refer to a plurality of (different) heat spreaders.

In embodiments, the heat spreader may comprise a two-phase cooling device. Two-phase cooling devices may be devices that transfer heat between two locations based on both thermal conductivity and phase transition. In particular, liquid, such as water (e.g. for a copper device) or acetone (e.g. for an aluminum device), may be added to the two-phase cooling device and the two-phase cooling device may be vacuum sealed. When heat is applied to one area of the two-phase cooling device, the liquid may turn to vapor and move to an area of lower pressure where it cools and returns to liquid form whereupon it moves back to the heat source.

In embodiments, the two-phase cooling device may especially comprise a heat pipe or a vapor chamber element, especially a vapor chamber element. Vapor chamber elements and heat pipes are known in the art and may be based on essentially the same principle. A difference between the heat pipe and the vapor chamber element may be that the heat pipe may typically have an essentially rod-shaped shape, whereas the vapor chamber element may in general have a planar shape. In particular, the vapor chamber element may include two essentially planar plates at a relative short distance (such as up to 5 mm). Further, for the vapor chamber element the hot spot may relatively freely be chosen, whereas for a heat pipe there is generally a hot and cold side at the opposing sides of the rod, such as at the bases of a cylinder-shaped heat pipe.

The two-phase cooling device may have a device wall, especially wherein the device wall defines an elongated chamber. In particular, the device wall may enclose the chamber. The device wall may generally be airtight. The device wall may especially comprise a thermally conductive material selected from the group comprising copper, aluminum, stainless steel, titanium, nickel, Monel, tungsten, niobium, tungsten, molybdenum and Inconel. In particular, a medium temperature two-phase cooling device may comprise nickel, and a high temperature two-phase cooling device may comprise one or more of Monel, tungsten, niobium, molybdenum and Inconel. In embodiments, also material combinations, of e.g. two or more metals, may be applied, such as alloys. A two-phase cooling device configured for functional coupling to a luminescent body may especially have a device wall comprising a thermally conductive material selected from the group comprising copper, aluminum, stainless steel, nickel and titanium, which may be particularly suitable for the operational temperatures of such a system. In further embodiments, the device wall may comprise a material with low thermal expansion coefficient, especially a ceramic material, more especially (quartz) glass.

In particular, a low thermal expansion coefficient may result in a lower mechanical stress, which may in turn enable (locally) reducing the thickness further. For instance, quartz glass may have a thermal expansion close to 0 allowing to heat the quartz glass at one side and extremely cool it down on the other side without destroying the glass, which may facilitate obtaining a smaller AT.

The chamber may especially be an elongated chamber, especially wherein an axis of elongation of the chamber is perpendicular to the contact region. The device axis may especially be parallel to the axis of elongation of the chamber. As indicated in https://www.dnp.co.jp/eng/biz/case/detail/10162048_2493.html, both heat pipes and vapor chambers are two-phase devices used as thermal management solutions. A heat pipe may be a device with high thermal conductance that can transport large amounts of heat with a slight temperature difference between its hot and cold ends. On the other hand, a vapor chamber may be composed of flat heat pipes with very high thermal conductance, having flat surfaces on the top and bottom sides. When compared to traditional solutions like copper heat spreaders, heat pipes and vapor chambers have many strengths. First, they have a higher thermal conductivity. Second, the density of the heat pipe and vapor chamber is much lower than that of copper. Because of its hollow structure, the heat spreaders made by vapor chambers are much lighter than those made of copper. These properties make them stand out as ideal thermal management solutions. A vapor chamber may have a metal enclosure that is vacuum sealed, an internal wick structure installed inside, and a working fluid that moves within the system thanks to capillary action. In detail, the heat source may make direct contact with a portion of the vapor chamber and a finned heatsink attached to the top. Some of the working fluid may vaporize and flow to cooler areas. Heat absorption causes the vapor to condense and return to liquid which is reabsorbed by the wick structure and distributed to the heat source. As for the most common configuration, a vapor chamber houses vapor within a chamber instead of a pipe, and that’s why it is called a vapor chamber. The vapor chamber may be a planar heat pipe, which can spread heat in two dimensions, using its entire body to cool the heat source. In embodiments, its flat structure may allow heat to be transferred evenly through a very small space. A vapor chamber may basically be considered as a flat heat pipe. Vapor chambers may usually be composed of thin plates having precisely formed grooves and a wick structure sealed together. They may also be filled with a small amount of fluid, such as de-ionized water, which may allow heat to be dispersed away from the source. The cooling efficiency of heat pipes may be reduced when the pipes are bent or thinned because of its structure. But vapor chambers can be thinned to 0.25 - 0.2 mm thick. Strength of a heat pipe may be: high conductance and flexible in design. Strengths of a vapor chamber may be: high conductance, capable of transferring a large amount of heat, can be made very thin, the heat transfer can stay efficient even when a heat source is high, the planar structure is capable of diffusing heat instantaneously, even for a large area. Both devices have excellent heat transport efficiency for dissipating heat. While heat pipes may remove heat from the heat source, vapor chambers spread heat. As for heat pipes, they may be bent and installed in all directions. This provides heat pipes with design flexibility and enables them to be used alone, in combination, and in different positions. Vapor chambers may also be bent. Vapor chamber may be planar which may have impact on the freedom to bend the vapor chamber. In specific embodiments, the vapor chamber may be bent. Especially, at least part of the vapor chamber may be configured in physical and/or thermal contact with the hollow front section wall. More especially, at least part of the vapor chamber may have a shape conformal with the hollow front section wall. In further embodiments, the PCB may be configured in physical contact with the vapor chamber (or other two-phase cooling device).

Additionally or alternatively, the heat spreader may in embodiments comprise a metal core printed circuit board (MCPCB). In such embodiments, the MCPCB may be part of the heat spreader. Such MCPCB may be suitable for manufacturing via deep drawing because of the metal core of the MCPCB. In embodiments, the MCPCB may be bent. Especially, at least part of the MCPCB may be configured in physical and/or thermal contact with the hollow front section wall. More especially, at least part of the MCPCB may have a shape conformal with the hollow front section wall. In this way, the heat spreader may comprise at least part of an electrical arrangement of the light generating system. The electrical arrangement may herein especially comprise one or more of a printed circuit board (PCB) and an electrical component, especially one or more of a PCB and the light generating device. In yet further embodiments, the heat spreader may comprise a vapor chamber and an MCPCB. In specific embodiments, at least part of the heat spreader wall may comprise the MCPCB. In this way, any heat produced by the electrical arrangement may be efficiently transferred to the hollow front section. Hence, in specific embodiments, the heat spreader comprises one or more of a metal core printed circuit board and a vapor chamber.

Hence, in embodiments the light generating device may be functionally coupled to a metal core printed circuit board, wherein in specific embodiments the metal core printed circuit board is the heat spreader or is comprised by the heat spreader. Hence, the heat spreader may comprise in embodiments a folded or bent two- phase cooling device or folded or bent MCPCB.

Also, the hollow front section (wall) may in embodiments comprise a thermally conductive material. The hollow front section (wall) may in embodiments comprise one or more of aluminum, copper, zinc, steel, stainless steel, and plastic. In embodiments, the hollow front section (wall) may comprise aluminum.

As indicated above, in embodiments, the lamp module may further comprise a heatsink. The heatsink may in embodiments be arranged in the hollow front section. Especially, the heatsink may comprise a heatsink wall. The heatsink may comprise a heatsink shape. In embodiments, the heatsink shape may be similar to (at least part of) the hollow front section shape and/or to the heat spreader shape. Especially, the heatsink wall may in embodiments comprise a shape conformal with at least part of the hollow front section (wall). Additionally or alternatively, the heatsink wall may in embodiments comprise a shape conformal with at least part of the heat spreader wall.

Especially, at least part of the heatsink may in embodiments be configured in thermal contact with at least part of the heat spreader wall and/or with at least part of the hollow front section wall, thereby providing a layer stack partition. The layer stack partition may in embodiments comprise at least part of the heatsink wall, at least part of the heat spreader wall, and at least part of the hollow front section wall. In other words, the layer stack partition may comprise a stack of at least part of the heat spreader wall, at least part of the heatsink wall, and at least part of the hollow front section wall, wherein each may be configured in in thermal contact with at least one of the others (and at least one has contact with both others). In embodiments, the heat spreader wall may be configured between the heatsink wall and the front section wall. In such embodiment, the heat spreader wall may be configured in thermal and physical contact with both the heatsink wall and the front section wall, whereas the heatsink wall and the front section wall may be configured in thermal contact. In alternative embodiments, the heatsink wall may be configured between the heat spreader wall and the front section wall. In such embodiment, the heatsink wall may be configured in thermal and physical contact with both the heat spreader wall and the front section wall, whereas the heat spreader wall and the front section wall may be configured in thermal contact. In embodiments, the heatsink (wall) may comprise one or more of aluminum, copper, zinc, steel, and stainless steel. Hence, in specific embodiments the lamp module further comprises a heatsink, wherein the heatsink is arranged in the hollow front section, wherein the heatsink comprises a heatsink wall comprising a shape conformal with at least part of the hollow front section, wherein at least part of the heatsink is configured in thermal contact with at least part of the heat spreader wall and/or with at least part of the hollow front section wall; thereby providing a layer stack partition comprising at least part of the heatsink wall, at least part of the heat spreader wall, and at least part of the hollow front section wall, wherein the heat spreader wall is configured between the heatsink wall and the front section wall, or wherein the heatsink wall is configured between the heat spreader wall and the front section wall. In this way, the lamp module may dissipate heat even more efficiently.

Also the heatsink may be in embodiments be tapering. Hence, in embodiments a shape of the heatsink wall may be chosen such, that the heatsink tapers.

The system, or apparatus, or device may execute an action in a “mode” or “operation mode” or “mode of operation” or “operational mode”. The term “operational mode may also be indicated as “controlling mode”. Likewise, in a method an action or stage, or step may be executed in a “mode” or “operation mode” or “mode of operation” or “operational mode”. This does not exclude that the system, or apparatus, or device may also be adapted for providing another controlling mode, or a plurality of other controlling modes. Likewise, this may not exclude that before executing the mode and/or after executing the mode one or more other modes may be executed.

However, in embodiments a control system may be available, that is adapted to provide at least the controlling mode. Would other modes be available, the choice of such modes may especially be executed via a user interface, though other options, like executing a mode in dependence of a sensor signal or a (time) scheme, may also be possible. The operation mode may in embodiments also refer to a system, or apparatus, or device, which can only operate in a single operation mode (i.e. “on”, without further tunability).

Hence, in embodiments the light generating system may comprise a control system. The control system may in embodiments comprise a driver. Especially, the driver may in embodiments be configured within the housing and external from the heat spreader. In further embodiments, the driver may be functionally coupled to the light generating device. Hence, in specific embodiments, the light generating system comprises a control system, wherein the control system comprises a driver, wherein the driver is configured within the housing and external from the heat spreader, wherein the driver is functionally coupled to the light generating device. Hence, in embodiments, the control system may control in dependence of one or more of an input signal of a user interface, a sensor signal (of a sensor), and a timer. The term “timer” may refer to a clock and/or a predetermined time scheme.

The term “controlling” and similar terms especially refer at least to determining the behavior or supervising the running of an element. Hence, herein “controlling” and similar terms may e.g. refer to imposing behavior to the element (determining the behavior or supervising the running of an element), etc., such as e.g. measuring, displaying, actuating, opening, shifting, changing temperature, etc. Beyond that, the term “controlling” and similar terms may additionally include monitoring. Hence, the term “controlling” and similar terms may include imposing behavior on an element and also imposing behavior on an element and monitoring the element. The controlling of the element can be done with a control system, which may also be indicated as “controller”. The control system and the element may thus at least temporarily, or permanently, functionally be coupled. The element may comprise the control system. In embodiments, the control system and element may not be physically coupled. Control can be done via wired and/or wireless control. The term “control system” may also refer to a plurality of different control systems, which especially are functionally coupled, and of which e.g. one control system may be a master control system and one or more others may be slave control systems. A control system may comprise or may be functionally coupled to a user interface.

The control system may also be configured to receive and execute instructions from a remote control. In embodiments, the control system may be controlled via an App on a device, such as a portable device, like a Smartphone or I-phone, a tablet, etc. The device is thus not necessarily coupled to the light generating system but may be (temporarily) functionally coupled to the light generating system.

Hence, in embodiments the control system may (also) be configured to be controlled by an App on a remote device. In such embodiments the control system of the light generating system may be a slave control system or control in a slave mode. For instance, the light generating system may be identifiable with a code, especially a unique code for the respective light generating system. The control system of the light generating system may be configured to be controlled by an external control system which has access to the light generating system on the basis of knowledge (input by a user interface of with an optical sensor (e.g. QR code reader) of the (unique) code. The light generating system may also comprise means for communicating with other systems or devices, such as on the basis of Bluetooth, Thread, WIFI, LiFi, ZigBee, BLE or WiMAX, or another wireless technology. Hence, in embodiments, the control system may comprise an antenna. In such embodiments, the control system may communicate with other systems or devices as indicated above. In embodiments, the antenna may be configured within the housing. In further embodiments, the antenna may be configured within (a space of) the heat spreader. Especially, the antenna may in embodiments be functionally coupled to the driver. The antenna may be any type of antenna, e.g. the antenna may in embodiments be an IFA or PIFA. In embodiments wherein the control system comprises an antenna, the front section wall may comprise a housing wall opening. Additionally or alternatively, the heat spreader wall may comprise a heat spreader wall opening. Especially, the heat spreader wall opening may in embodiments at least partly aligned with the housing wall opening. In further embodiments, the heat spreader wall opening and the housing wall opening may be closed with a closure. Especially, the closure may in embodiments be more transmissive for radio (frequency) waves than the front section wall and the heat spreader wall. In this way, the antenna may be functionally (or communicationally) coupled to the driver. In further embodiments, the closure may be transmissive for radio (frequency) waves, in contrast to the front part wall and the heat spreader wall. In embodiments, the closure may comprise one or more of a plastic and glass. In further embodiments, the closure may comprise the same material as (part of) the optical element. In such embodiments, the optical element and the closure may be monolithic. However, in alternative embodiments the optical element and the closure may be separate parts. Hence, in specific embodiments, the control system comprises an antenna, wherein the antenna is configured within the housing, wherein the antenna is functionally coupled to the driver; and wherein the front section wall comprises a housing wall opening and wherein the heat spreader wall comprises a heat spreader wall opening, at least partly aligned with the housing wall opening, wherein the heat spreader wall opening and the housing wall opening are closed with a closure, wherein the closure is more transmissive for radio waves than the front section wall and the heat spreader wall (hence, the closure may even be more transmissive for radio waves than the combination of the front section wall and the heat spreader wall).

The light generating system may be part of or may be applied in e.g. office lighting systems, household application systems, shop lighting systems, home lighting systems, accent lighting systems, spot lighting systems, theater lighting systems, fiber-optics application systems, projection systems, self-lit display systems, pixelated display systems, segmented display systems, warning sign systems, medical lighting application systems, indicator sign systems, decorative lighting systems, portable systems, automotive applications, (outdoor) road lighting systems, urban lighting systems, green house lighting systems, horticulture lighting, digital projection, or LCD backlighting. The light generating system (or luminaire) may be part of or may be applied in e.g. optical communication systems or disinfection systems.

The term “white light”, and similar terms, herein, is known to the person skilled in the art. It may especially relate to light having a correlated color temperature (CCT) between about 1800 K and 20000 K, such as between 2000 and 20000 K, especially 2700- 20000 K, for general lighting especially in the range of about 2000-7000 K, such as in the range of 2700 K and 6500 K. In embodiments, e.g. for backlighting purposes, or for other purposes, the correlated color temperature (CCT) may especially be in the range of about 7000 K and 20000 K. Yet further, in embodiments the correlated color temperature (CCT) is especially within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), especially within about 10 SDCM from the BBL, even more especially within about 5 SDCM from the BBL. The terms “visible”, “visible light” or “visible emission” and similar terms refer to light having one or more wavelengths in the range of about 380-780 nm. Herein, UV may especially refer to a wavelength selected from the range of 190-380 nm, such as 200-380 nm. The terms “light” and “radiation” are herein interchangeably used, unless clear from the context that the term “light” only refers to visible light. The terms “light” and “radiation” may thus refer to UV radiation, visible light, and IR radiation. In specific embodiments, especially for lighting applications, the terms “light” and “radiation” refer to (at least) visible light.

In a further aspect, the invention also provides a lamp or a luminaire comprising the light generating system as defined herein. The luminaire may further comprise a housing, optical elements, louvres, etc. The lamp or luminaire may further comprise a housing enclosing the light generating system. The lamp or luminaire may comprise a light window in the housing or a housing opening, through which the system light may escape from the housing. In yet a further aspect, the invention also provides a projection device comprising the light generating system as defined herein. Especially, a projection device or “projector” or “image projector” may be an optical device that projects an image (or moving images) onto a surface, such as e.g. a projection screen. The projection device may include one or more light generating systems such as described herein. Hence, in an aspect the invention also provides a lighting device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, an automotive lighting device, and an optical wireless communication device, comprising the light generating system as defined herein. The lighting device may comprise a housing or a carrier, configured to house or support, one or more elements of the light generating system. For instance, in embodiments the lighting device may comprise a housing or a carrier, configured to house or support the light generating system.

Instead of the terms “lighting device” or “lighting system”, and similar terms, also the terms “light generating device” or “light generating system”, (and similar terms), may be applied. A light generating device or a light generating system may be configured to generate device light (or “lighting device light”) or system light (“or lighting system light”). As indicated above, the terms light and radiation may interchangeably be used.

The lighting device may comprise a light source. The device light may in embodiments comprise one or more of light source light and converted light source light (such as luminescent material light).

In yet a further aspect, the invention also provides a method of assembly of the light generating system. The method may in embodiments comprise arranging the heat spreader within the housing via the housing front opening. In further embodiments, the method may comprise arranging the light generating device into the heat spreader. Especially, the method may in embodiments comprising the heat spreader such that the light generating device is in thermal contact with the heat spreader. In yet further embodiments, the method may comprise functionally coupling the optical arrangement to the housing thereby securing one or more of the optical arrangement to the housing. Hence, in specific embodiments the invention provides a method of assembly of the light generating system wherein the method comprises: (i) arranging the heat spreader within the housing via the housing front opening and arranging the light generating device into the heat spreader; and (ii) functionally coupling the optical arrangement to the housing thereby securing the optical arrangement to the housing. In this way, the light generating system of the invention may be obtained. In yet an aspect, the invention provides a method of assembly of the light generating system wherein the method comprises: (i) arranging the heat spreader (which may comprise a MCPCB with the light generating device functionally coupled thereto) within the housing via the housing front opening into the heat spreader, wherein the light generating device is functionally coupled to the heat spreader; and (ii) functionally coupling the optical arrangement to the housing thereby securing the optical arrangement to the housing. The heat spreader may thereby enclosed in the housing, and may be kept in place by the inward fold.

Embodiments described above in relation to the light generating system, may also apply to the method of the invention. Here, some embodiments are repeated. As indicated above, the heat spreader may in embodiments comprise one or more of a metal core printed circuit board and a vapor chamber. Also, the heat spreader may in embodiments be manufactured via one or more of deep drawing, casting, high pressure die casting, forging, injection molding, and rubber pressing. Similarly, the housing may in embodiments be manufactured via one or more of deep drawing, casting, high pressure die casting, forging, injection molding, and rubber pressing.

As indicated above, the heat spreader (wall) may in embodiments comprise a thermally conductive material. The heat spreader may in embodiments comprise one or more of aluminum, copper, zinc, steel, stainless steel, and plastic. In embodiments wherein the lamp module (especially the control system) comprises an antenna, the front section wall may comprise a housing wall opening. Additionally or alternatively, the heat spreader wall may comprise a heat spreader wall opening. Especially, the heat spreader wall opening may in embodiments at least partly aligned with the housing wall opening. In further embodiments, the heat spreader wall opening and the housing wall opening may be closed with a closure. Especially, the closure may in embodiments be more transmissive for radio (frequency) waves than the front section wall and the heat spreader wall.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

Fig. la-b schematically depicts embodiments of the invention;

Fig. 2a-b schematically depicts further embodiments of the invention; also Fig. 3a-c schematically depicts further embodiments of the invention;

Fig. 4 schematically depicts embodiments of the method of the invention; and Fig 5 schematically depicts applications of the invention.

The schematic drawings are not necessarily to scale.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Fig. la schematically depicts the light generating system 1000 comprising a lamp module 2000. O may herein indicate an optical axis of the lamp module 2000. The lamp module 2000 may comprise a housing 500, a heat spreader 600, a light generating device 100, and (iv) an optical arrangement 700. The housing 500 may in embodiments comprise a hollow front section 510, wherein the hollow front section 510 may comprise a housing front opening 513. The hollow front section 510 may have a front section height Hl. Especially, the hollow front section 510 may taper over at least part of the front section height Hl in a direction away from the housing front opening 513. The hollow front section 510 may comprise a hollow front section wall 520.

In the depicted embodiment, the heat spreader 600 has a cup-like shape. The heat spreader 600 may in embodiments comprise a heat spreader front opening 613. The heat spreader 600 may have a heat spreader height H2. In embodiments, the heat spreader 600 may taper over at least part of the heat spreader height H2 in a direction away from the heat spreader front opening 613. The heat spreader 600 may in embodiments comprise a heat spreader wall 620. Especially, the heat spreader wall 620 may comprise a thermally conductive material. In embodiments, the heat spreader 600 may be arranged in the hollow front section 510, wherein at least part of the heat spreader wall 620 may be conformal with the hollow front section wall 520 and may be configured in thermal contact with at least part of the hollow front section wall 520. Especially, a shape of the heat spreader wall 620 over at least part of the heat spreader height (H2) may be conformal to a shape of the hollow front section wall 520 and in physical contact therewith. In embodiments, the heat spreader wall 620 may be reflective for the device light 101.

In embodiments, the light generating device 100 may be configured to generate device light 101 (in an operational mode of the light generating system). In embodiments, the light generating device 100 may at least partly be configured in the heat spreader 600. In embodiments, the light generating device 100 may especially be configured in thermal contact with the heat spreader 600. As depicted in Fig la, the light generating system 1000 may (in an operational mode of the light generating system) be configured to generate system light 1001. Especially, the system light 1001 may comprise device light 101 escaped from the hollow front section 510 via the optical arrangement 700.

The optical arrangement 700 may in embodiments comprise an optical element 710. Especially, the optical element 710 may be configured downstream of the light generating device 100. In embodiments, the optical element 710 may be transmissive (such as transparent) for the device light 101. In further embodiments, the optical arrangement 700 may be transmissive (such as transparent) for the device light 101.

The optical arrangement 700 may in embodiments be attached to the hollow front section 510. Additionally or alternatively, the optical arrangement 700 may at least be partly configured in the housing front opening 513. In embodiments, the optical arrangement may be configured to keep the heat spreader 600 arranged in the hollow front section 510. In the depicted embodiment, the optical element 710 comprises a Fresnel lens.

The housing front opening 513 may have a housing front opening diameter DI. Similarly, the optical arrangement 700 may have an optical arrangement diameter D2. In embodiments, D2>D1, especially wherein 1.02<D2/Dl<1.5, such as 1.02<D2/Dl<1.2.

In further embodiments, the light generating system 1000 may comprise a control system 300. The control system 300 may especially comprise a driver 310. In embodiments, the driver 310 may be configured within the housing 500 and external from the heat spreader 600. In an operational mode of the system, the driver 310 may in embodiments be functionally coupled to the light generating device 100.

An enlargement of the circled area in Fig. la is depicted in more detail in Fig. lb. In this enlargement, an embodiment of the invention is depicted wherein the optical arrangement 700 is attached to the hollow front section 510 via a click connection 811,812. Especially, in the depicted embodiment, the hollow front section 510 comprises a first feature 511 that is protruding relative to (a remainder of) the hollow front section 510. Herein, the optical arrangement 700 comprises a second feature 711 that is recessed relative to (a remainder of) the optical arrangement. Especially, the first feature 511 and the second feature 711 may form the click connection 811,812. In alternative embodiments, the hollow front section 510 comprises the first feature 511 that may be recessed relative to (a remainder of) the hollow front section 510 and wherein the optical arrangement 700 comprises a second feature 711 that is protruding relative to (a remainder of) the optical arrangement. In further embodiments, the first feature 511 may be comprised by the front section wall 520 or functionally coupled thereto.

The hollow front section 510 may in embodiments comprise a front section rim 530. Especially, the optical arrangement 700 may in embodiments at least partly enclose the front section rim 530. In further embodiments, the first feature 511 may be functionally coupled to the front section rim 530. In such embodiments, the front section rim 530 may be defined by the front section wall 520 and the first feature 511.

Fig. 2a schematically depicts several embodiments of the front section rim 530. However, other embodiments of the front section 530 rim are herein not excluded. In embodiments, the front section rim 530 may comprise one or more of a linear section and a circular section. As schematically depicted in embodiment I, the hollow front section 510 (especially the hollow front section wall 520 may comprise an inward fold 560. Especially, the inward fold 560 may comprise a first inward bend 561 having a first angle (ai) relative to a tangential (T) to the front section wall 520. Especially, the first angle (ai) may be defined as the angle over which the hollow front section wall 520 may be curved. In embodiments, the first angle (ai) may be selected from the range of 0° to 360° such as from the range of 0° to 270°. In alternative embodiments, ai>360°. In the depicted embodiment, first angle ai= 130°. In further embodiments, the first feature 511 may comprise the inward fold 560. Embodiment II schematically depicts an open hem and embodiment III schematically depicts a flat hem. Both embodiments II and III may essentially correspond to an inward fold 560 comprising a first inward bend 561 having a first angle ai = 180°. Embodiment IV schematically depicts a teardrop hem, which may essentially correspond to an inward fold 560 comprising a first inward bend 561 having a first angle ai = 185°. Embodiment V schematically depicts an inward fold 560 comprising a first inward bend 561 having a first angle ai and a second inward bend 562 having a second angle 012. In the depicted embodiment, ai = 130° and 012 = 90°. Embodiment VI schematically depicts a rolled hem and embodiment VII schematically depicts a rope hem. Embodiments VI may be considered as a continuous bend and/or as a single inward bend 561 wherein in embodiment ai = 270°. Embodiment VII may be considered as an inward fold 560 comprising a fist inward bend 561 having a first angle ai = 230°, followed by an outward bend (not discussed here).

Fig. 2b schematically depicts embodiments of the front section rim 530 applied to the housing 500. Embodiment I depicts a relatively long front section rim 530 having a first inward bend 561. Embodiments II and III depict shorter front section rims 530 combined with different shapes of the optical parts 700. Embodiment IV depicts a front section rim 530 having a first inward bend 561 and a second inward bend 562. In the depicted embodiments, both the heat spreader 600 and the optical element 700 are attached behind the front section rim 530.

Fig. 3a schematically depicts a part of the lamp module 500. For the sake of clarity, the rim 530 and inward fold 560 are not depicted here. The heat spreader 600 may comprise an external surface 601 and an internal surface 602, each at least partly defined by the heat spreader wall 620. In embodiments, at least 10% of a surface area of the external surface 601 may be configured in physical contact with the front section wall 520. Additionally or alternatively, in embodiments, at least 20% of a surface area of an external wall surface 601a of the heat spreader wall 620 may be configured in physical contact with the front section wall 520.

Fig. 3b schematically depicts an embodiment wherein the lamp module 2000 further comprises a heatsink 590. Especially, the heatsink 590 may arranged in the hollow front section 510. The heatsink 590 may comprise a heatsink wall 595. In embodiments, the heatsink wall 595 may comprise a shape conformal with at least part of the hollow front section 510. In embodiments, at least part of the heatsink 590 may be configured in thermal contact with at least part of the heat spreader wall 620 and with at least part of the hollow front section wall 520; thereby providing a layer stack partition 599 comprising at least part of the heatsink wall 595, at least part of the heat spreader wall 620, and at least part of the hollow front section wall 520. In the depicted embodiment, the heatsink wall 595 is configured between the heat spreader wall 620 and the front section wall 520. In such embodiment, the heat spreader wall 620 may not be in physical contact with the hollow front section wall 520, but the heat spreader wall 620 may be in thermal contact with the hollow front section wall 520. However, in embodiments the heat spreader wall 620 may be larger than the heatsink wall 595 and still be in physical contact with the hollow front section wall 520. In another embodiment according to the invention, the heat spreader wall 620 may be configured between the heatsink wall 595 and the front section wall 520. In such embodiment, the heat spreader wall 620 may be in physical and thermal contact with the hollow front section wall 520.

Fig. 3c schematically depicts further embodiments of the rim 530 and inward folds from a plane perpendicular to the optical axis. Embodiment I schematically depicts the rim 530 comprising three inward folds. In such embodiments, the inward fold may comprise an inward fold circle section. Here, the inward fold circle section may comprise approximately up to about 20°, such as about 10°. In between the inward folds, the rim may further comprise circle sections without an inward fold. Embodiment II schematically depicts the inward fold being a continuous fold around a perimeter of the rim 530. In such embodiments, the rim 530 may comprise a full circle inward fold of 360°.

In embodiments, the heat spreader 600 may comprise a deep drawn heat spreader 600. Additionally or alternatively, the heat spreader 600 may comprise one or more of aluminum, copper, zinc, steel, stainless steel, and plastic. In such embodiments, the heat spreader 600 may especially have a thermal conductivity selected from the range of 0.1-420 W/mK.

In further embodiments, the heat spreader 600 may comprise a metal core printed circuit board (MCPCB) 1100. Additionally or alternatively, the heat spreader 600 may in embodiments comprise a vapor chamber (not depicted here). The light generating device 100 may in embodiments comprise a solid-state light source. The solid-state light source may in embodiments be selected from the group of a COB, a LED, a diode laser, and a superluminescent diode.

As indicated above, the light generating system 1000 may comprise a control system 300. In embodiments, the control system 300 may comprise an antenna 330. Especially, the antenna 330 may be configured within the housing 500. In an operational mode, the antenna 330 may be functionally coupled to the driver 310. The front section wall 520 may in embodiments comprise a housing wall opening 525. Additionally or alternatively, the heat spreader wall 620 may in embodiments comprise a heat spreader wall opening 625. Especially, the heat spreader wall opening may at least partly be aligned with the housing wall opening 525. In embodiments, the heat spreader wall opening 625 and the housing wall opening 525 may be closed with a closure 560. Especially, the closure may in embodiments be more transmissive for radio (frequency) waves than the front section wall 520 and the heat spreader wall 620.

Fig. 4 schematically depicts a method of assembly of the light generating system 1000. In embodiments, the method may comprise providing a housing 500 comprising a hollow front section 510 and a back section 515. Especially, the hollow front section 5110 may comprise a hollow front section wall 520 and a housing front opening 513. The method may comprise inserting electrical components 320 in the housing. The electrical components may in embodiments comprise one or more of electrical contacts, the driver, and the control system. However, other electrical components are herein not excluded. Next, the method may in embodiments comprise arranging the heat spreader 600 within the housing 500 via the housing front opening 513. Especially, the heat spreader may comprise a heat spreader wall 620, a heat spreader front opening 613, and a heat spreader height H2. Next, the method may comprise folding the housing to provide the front section rim 530. The front section rim 530 may configure the heat spreader 600 in physical contact with the front section wall 520. Especially, one or more of the front section rim 530 and the inward fold 560 may press the heat spreader 600 towards the front section wall 520. In this way, thermal contact between the heat spreader 600 and the front section wall 520 may be improved. The method may in embodiments further comprise arranging the light generating device 100 and optionally a PCB 1100 into the heat spreader 600. Especially, such that the light generating device 100 may be in thermal contact with the heat spreader 600. The method may in embodiments further comprise functionally coupling the optical arrangement 700 to the housing 500. Especially, the optical arrangement 700 may lock the inward fold 560, and hence lock the heat spreader 600 in place. In such embodiments, the optical arrangement 700 (and the heat spreader 600) may be secured to the housing 500.

Fig. 5 schematically depicts an embodiment of a luminaire 2 comprising the light generating system 1000 as described above. Reference 301 indicates a user interface which may be functionally coupled with the control system 300 comprised by or functionally coupled to the light generating system 1000. Fig. 5 also schematically depicts an embodiment of lamp 1 comprising the light generating system 1000. Reference 3 indicates a projector device or projector system, which may be used to project images, such as at a wall, which may also comprise the light generating system 1000. Hence, Fig. 5 schematically depicts embodiments of a light generating device 1200 selected from the group of a lamp 1, a luminaire 2, a projector device 3, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system 1000 as described herein. In embodiments, such lighting device may be a lamp 1, a luminaire 2, a projector device 3, a disinfection device, an automotive lighting device, or an optical wireless communication device. Lighting device light escaping from the lighting device 1200 is indicated with reference 1201. Lighting device light 1201 may essentially consist of system light 1001 and may in specific embodiments thus be system light 1001. Reference 1300 refers to a space, such as a room.

The term “plurality” refers to two or more. The terms “substantially” or “essentially” herein, and similar terms, will be understood by the person skilled in the art. The terms “substantially” or “essentially” may also include embodiments with “entirely”, “completely”, “all”, etc. Hence, in embodiments the adjective substantially or essentially may also be removed. Where applicable, the term “substantially” or the term “essentially” may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%. The term “comprise” also includes embodiments wherein the term “comprises” means “consists of’. The term “and/or” especially relates to one or more of the items mentioned before and after “and/or”. For instance, a phrase “item 1 and/or item 2” and similar phrases may relate to one or more of item 1 and item 2. The term "comprising" may in an embodiment refer to "consisting of but may in another embodiment also refer to "containing at least the defined species and optionally one or more other species". Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

The devices, apparatus, or systems may herein amongst others be described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation, or devices, apparatus, or systems in operation.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Use of the verb "to comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a device claim, or an apparatus claim, or a system claim, enumerating several means, several of these means may be embodied by one and the same item of hardware. 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. In yet a further aspect, the invention (thus) provides a software product, which, when running on a computer is capable of bringing about (one or more embodiments of) the method as described herein.

The invention also provides a control system that may control the device, apparatus, or system, or that may execute the herein described method or process. Yet further, the invention also provides a computer program product, when running on a computer which is functionally coupled to or comprised by the device, apparatus, or system, controls one or more controllable elements of such device, apparatus, or system.

The invention further applies to a device, apparatus, or system comprising one or more of the characterizing features described in the description and/or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and/or shown in the attached drawings.

The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.

Common spot lamps typically may have high power density, so they may dissipate relatively high amount of power in relatively small volume. Therefore, construction of spot lamps may need to provide very efficient cooling to maintain temperature of the light generating device and driver components within allowed limits.

Typically, housing of spot lamps (such as MR16) may be made using high pressure die casting (HPDC) technique, which may provide design flexibility. However, HPDC may have some drawbacks, such as high investment cost (hard tooling), long lead time, high cost of the housing, low thermal performance of die casted material (approx. (90- 120 W/mK), and/or post processing (milling) step may be needed.

In contrast, thermal conductivity of pure aluminum is very high (230 W/mK). Pure aluminum may however be too soft for majority of applications. Therefore, a number of additives may be needed to improve mechanical properties and castability. Those additives may have negative impact on thermal performance.

Materials used for deep drawing may show much higher thermal conductivity than HPDC materials. This may be mainly because materials for deep drawing may not need additives which HPDC materials may need. For this reason, a lamp concept based on application of deep drawn pars is proposed in this invention.

In a light generating system according to the present invention, heat may be conducted from the light generating device through the heat spreader towards the housing. The heat spreader may overlap with the housing with a relatively large contact surface area. In this way, a thermal interface between those two parts may be highly effective. The housing may be folded on top of the heat spreader to lock the position of the heat spreader and to compress it towards the housing. Such way of assembly may improve thermal contact between the heat spreader and the housing and may improve overall cooling performance of the light generating system.

In further embodiments, the same fold of the housing may be used for snap-in mounting of an optical element such as a lens. In embodiments, the optical element may also be a counter lock of the heat spreader. Once the optical element is pushed in place, the fold may be unable to unfold. Therefore heat spreader may not get loose, and thermal contact between the heatsink and the heat spreader may be well maintained.

Especially, a geometry of the heat spreader in combination with high thermal conductivity of deep drawn material (approx. 190-220 W/mK) may enforce heat transport to the section of the housing below the light generating device. In such way the whole housing surface may be effectively used for cooling.

In further embodiments, the optical component such as the lens may be the only visible component after lamp is mounted in the lamp holder. This may avoid a presence of dark spots on the top side of this lamp in “on” state, especially the complete lens may be illuminated. Additionally or alternatively, a metal part of the housing may not be exposed to the user anymore and restrictions related to the touch temperature may become less harsh. In such way it is possible to increase the output power of the spot lamp and/or avoid derating.

In embodiments, the heat spreader may have opening(s) in different shapes and location(s) which may be used for one or more of: (a) Interconnection between the light generating device and the driver, (b) Clearance for the components mounted on the PCB and/or on the driver, (c) Keying with other parts and/or components, (d) RF connectivity, and (e) Mounting provision (e.g. threaded screw hole, keyhole, etc.).

In further embodiments, the housing geometry may have additional pockets and/or folds which may increase an outer surface of the housing and may improve further cooling performance of the housing.

To improve connectivity of the lamp, there may in embodiments be a cut-out on the side of the housing. Such cut-out would allow RF signal to go pass through the housing. A closure part may be used to close the cut-out. In embodiments, the closure may comprise a plastic part.

Especially, the invention may provide one or more of the following advantages: (a) Lower cost of the housing, (b) More effective cooling due to: (i) Higher thermal conductivity of deep drawn materials in comparison to HPDC materials, (ii) Large overlapping surface between light generating device and heat spreader, and heat spreader and the housing, (iii) Compression of the heat spreader towards the housing by inward fold of the housing, (c) Increased touch temperature limit in the sleeve from 73 °C to 90°C in embodiments wherein the lens covers complete top side, (d) Sustainability: (i) No heat generation in forming process, (ii) Uniform wall thickness, (iii) Much smaller energy consumption in the manufacturing process, (iv) Less material waste in manufacturing process, (e) Look and feel: housing rim may not be visible while lamp is mounted in the lamp holder, no dark ring in “on” state, (f) More space for electronics inside the housing (larger components may spread heat more effectively and/or may contribute to increased efficiency of electrical circuits), and (g) Universal assembly principle which may be applied to different spot lamp variants: MR16, GU4, GU10, G4, G5.3, G6.35, G9, GX5.3, etc.

Claims

CLAIMS:

1. A light generating system (1000) comprising a lamp module (2000), wherein the lamp module (2000) comprises (i) a housing (500), (ii) a heat spreader (600), (iii) a light generating device (100), and (iv) an optical arrangement (700), wherein: the housing (500) comprises a hollow front section (510), wherein the hollow front section (510) comprises a housing front opening (513), wherein the hollow front section (510) has a front section height (Hl), wherein the hollow front section (510) tapers over at least part of the front section height (Hl) in a direction away from the housing front opening (513), wherein the hollow front section (510) comprises a hollow front section wall (520); the heat spreader (600) has a cup-like shape, wherein the heat spreader (600) comprises a heat spreader front opening (613), wherein the heat spreader (600) has a heat spreader height (H2), wherein the heat spreader (600) tapers over at least part of the heat spreader height (H2) in a direction away from the heat spreader front opening (613); wherein the heat spreader (600) comprises a heat spreader wall (620), wherein the heat spreader wall (620) comprises a thermally conductive material; wherein the heat spreader (600) is arranged in the hollow front section (510), wherein at least part of the heat spreader wall (620) is configured in thermal contact with at least part of the hollow front section wall (520); the light generating device (100) is configured to generate device light (101); wherein the light generating device (100) is at least partly configured in the heat spreader (600), and is configured in thermal contact with the heat spreader (600); and the optical arrangement (700) comprises an optical element (710), wherein the optical element (710) is configured downstream of the light generating device (100); wherein the optical element (710) is transmissive for the device light (101); wherein the optical arrangement (700) is attached to the hollow front section (510), and is at least partly configured in the housing front opening (513); wherein the optical arrangement (700) is attached to the hollow front section (510) via a click connection (811,812); wherein the hollow front section (510) comprises a first feature (511) that is protruding or recessed relative to the hollow front section (510), wherein the optical arrangement (700) comprises a second feature (711) that is recessed or protruding relative to the optical arrangement, and wherein the first feature (511) and the second feature (711) form the click connection (811,812); and wherein the first feature (511) is an inward fold (560) configured to hold the heat spreader in the hollow front section.

2. The light generating system (1000) according to claim 1, wherein the heat spreader wall (620) is reflective for the device light (101), wherein a shape of the heat spreader wall (620) over at least part of the heat spreader height (H2) is conformal to a shape of the hollow front section wall (520) and in physical contact therewith; and wherein the optical element (710) comprises a lens, wherein the lens comprises a Fresnel lens.

3. The light generating system (1000) according to any one of the preceding claims, wherein the heat spreader (600) comprises an external surface (601), at least partly defined by the heat spreader wall (620), wherein at least 10% of a surface area of the external surface (601) is configured in physical contact with the front section wall (520).

4. The light generating system (1000) according to any one of the preceding claims, wherein the inward fold is configured to hold the heat spreader in thermal contact with the hollow front section wall.

5. The light generating system (1000) according to any one of the preceding claims, wherein the hollow front section (510) comprises a front section rim (530), and wherein the optical arrangement (700) at least partly encloses the front section rim (530).

6. The light generating system (1000) according to claims 4-5, wherein the first feature (511) is functionally coupled to the front section rim (530).

7. The light generating system (1000) according to any one of the preceding claims, wherein the inward fold (560) comprises a first inward bend (561) having a first angle (ai) relative to a tangential (T) to the front section wall (520), wherein the first angle (ai) is selected from the range of 10° to 270°, wherein the first feature (511) as defined in any one of claims 4 and 6 comprises the inward fold (560).

8. The light generating system (1000) according to any one of the preceding claims, wherein the housing front opening (513) has a housing front opening diameter (DI), wherein the optical arrangement (700) has an optical arrangement diameter (D2), wherein D2>D1, wherein the optical arrangement (700) is transmissive for the device light (101).

9 The light generating system (1000) according to any one of the preceding claims, wherein the lamp module (2000) further comprises a heatsink (590), wherein the heatsink (590) is arranged in the hollow front section (510), wherein the heatsink (590) comprises a heatsink wall (595) comprising a shape conformal with at least part of the hollow front section (510), wherein at least part of the heatsink (590) is configured in thermal contact with at least part of the heat spreader wall (620) and with at least part of the hollow front section wall (520); thereby providing a layer stack partition (599) comprising at least part of the heatsink wall (595), at least part of the heat spreader wall (620), and at least part of the hollow front section wall (520), wherein the heat spreader wall (620) is configured between the heatsink wall (595) and the front section wall (520), or wherein the heatsink wall (595) is configured between the heat spreader wall (620) and the front section wall (520).

10. The light generating system (1000) according to any one of the preceding claims, wherein one or more of the following applies: (i) the heat spreader (600) comprises a deep drawn heat spreader (600); (ii) the heat spreader (600) comprises one or more of aluminum, copper, zinc, steel, stainless steel, and plastic; (iii) the heat spreader (600) has a thermal conductivity selected from the range of 0.1-420 W/mK; and (iv) the light generating device (100) comprises a solid-state light source, wherein the solid-state light source is selected from the group of a COB, a LED, a diode laser, and a superluminescent diode.

11. The light generating system (1000) according to any one of the preceding claims, wherein the heat spreader (600) comprises one or more of a metal core printed circuit board and a vapor chamber.

12. The light generating system (1000) according to any one of the preceding claims, wherein the light generating system (1000) comprises a control system (300), wherein the control system (300) comprises a driver (310), wherein the driver (310) is configured within the housing (500) and external from the heat spreader (600), wherein the driver (310) is functionally coupled to the light generating device (100).

13. The light generating system (1000) according to the preceding claim 12, wherein the control system (300) comprises an antenna (330), wherein the antenna (330) is configured within the housing (500), wherein the antenna (330) is functionally coupled to the driver (310); and wherein the front section wall (520) comprises a housing wall opening (525) and wherein the heat spreader wall (620) comprises a heat spreader wall opening (625), at least partly aligned with the housing wall opening (525), wherein the heat spreader wall opening (625) and the housing wall opening (525) are closed with a closure (560), wherein the closure is more transmissive for radio waves than the front section wall (520) and the heat spreader wall (620).

14. A lighting device (1200) selected from the group of a lamp (1), a luminaire (2), a projector device (3), a disinfection device, a photochemical reactor, an automotive lighting device, and an optical wireless communication device, comprising the light generating system (1000) according to any one of the preceding claims.

15. A method of assembly of the light generating system (1000) according to any one of the preceding claims 1-13, wherein the method comprises: arranging the heat spreader (600) within the housing (500) via the housing front opening (513) and arranging the light generating device (100) into the heat spreader (600); and functionally coupling the optical arrangement (700) to the housing (500) thereby securing the optical arrangement (700) to the housing (500).