An LED lighting device

Abstract

A lighting device having a printed circuit board with an aperture. A sealing mechanism is used to seal at least a portion of the sidewall of the aperture from fluid ingress. A washer of the sealing mechanism has a protruding portion that extends into the aperture and presses a gasket against a portion of the sidewall of the aperture, to thereby seal said portion. The protruding portion engages or secures to the sidewall using an interference fit in order to provide the force for pressing the gasket.

Description

[0001] An LED lighting device

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the field of artificial lighting.

[0004] BACKGROUND OF THE INVENTION

[0005] The increasing use of artificial light is causing a greater demand for artificial lighting devices, such as LED lighting devices. A typical lighting device will comprise a printed circuit board configured to support one or more light emitting devices, such as light emitting diodes (LEDs).

[0006] It is common for a printed circuit board of a lighting device to comprise one or more apertures. These apertures are commonly used to permit the passage of a screw therethrough, e.g., for securing the LED lighting device to a surface or component, or for securing the printed circuit board to another component.

[0007] The presence of one or more apertures exposes the printed circuit board to an external environment, e.g., allowing for liquid to ingress onto a surface of the printed circuit board via the aperture(s) and / or between layers of a multilayer printed circuit board.

[0008] There is an ongoing desire to improve the robustness of lighting devices to liquid ingress, e.g., to reduce the risk that liquid will reach elements carried by or on the printed circuit.

[0009] US 8167468B1 discloses an LED lighting fixture includes a metal core printed circuit board (MCPCB) having a rear side and a front side. At least one LED is mounted to the front side of the MCPCB. A transparent window is mounted and sealed to the front side of the MCPCB to enclose the LED. A portion of the MCPCB extends from the transparent window so that it can be in heat exchange contact with water when the window of the lighting fixture is submerged in water.

[0010] SUMMARY OF THE INVENTION

[0011] The invention is defined by the claims. According to examples in accordance with an aspect of the invention, there is provided a lighting device comprising a printed circuit board and a sealing mechanism.

[0012] The printed circuit board is configured to support one or more light emitting devices, wherein the printed circuit board comprises an aperture passing from a first surface to a second surface, the aperture having an inner sidewall.

[0013] The sealing mechanism comprises a sealing mechanism comprising: a gasket positioned to contact the inner sidewall of the aperture of the printed circuit board; and a washer comprising a protruding portion that extends into the aperture. The protruding portion is configured to engage with the inner sidewall of the aperture using an interference fit and squeeze the gasket between the washer and the inner sidewall of the aperture.

[0014] The present disclose proposes a sealing mechanism for an aperture in a printed circuit board that seals a portion of a sidewall of the aperture against fluid ingress. A gasket is positioned within the aperture so as to contact a portion of the sidewall to be sealed. A protruding portion of a washer couples against the sidewall and applies a pressure or force against the gasket so as to press the gasket against the portion of the sidewall to be sealed (thereby sealing said portion). In this way, the protruding portion acts to squeeze the gasket between itself and the sidewall, thereby sealing a portion of the sidewall against fluid ingress (i.e., so that less or no fluid is able to flow between the gasket and the sidewall).

[0015] The lighting device may further comprise a screw comprising: a head portion configured to engage with the washer; and a screw fitting configured to pass through the washer and the aperture of the printed circuit board for securing the lighting device to an external surface or component. By configuring the screw to engage with the washer (when securing to an external surface or component), the likelihood that the washer will shift and thereby cause the gasket to unseal the (portion of the) sidewall is reduced. This approach also increases a pressure applied by the washer to the gasket, to improve the sealing performance of the sealing mechanism.

[0016] In preferred examples, the surface of the protruding portion has a shape matching with the inner sidewall of the aperture. This approach facilitates a tight squeeze or fitting of the gasket between the washer and the inner sidewall of the aperture.

[0017] In preferred examples, the printed circuit board comprises a plurality of layers comprising at least one humidity-sensitive layer; and the gasket has a thickness sufficient to cover at least the at least one humidity-sensitive layer from the inner sidewall of the aperture. This approach reduces a risk of fluid ingress between layers of a multilayer printed circuit board (e.g., a MCPCB). In some examples, the printed circuit board comprises a plurality of layers and the gasket is positioned to contact, at the inner sidewall of the aperture, at least one boundary or interface between two or more of the plurality of layers. This approach causes the gasket to seal the previously exposed (to the aperture) edges of the boundary / boundaries between layers from fluid ingress, reducing a risk of inter-layer damage or moisture.

[0018] The washer may comprise a gasket restricting portion that extends from the protruding portion and over at least a portion of the gasket so as to restrict a movement of the gasket in a direction away from the aperture (e.g., in a direction towards a plane in which the first surface lies). This reduces a risk or likelihood that the gasket will shift or change position, thereby affecting the seal that it makes with the sidewall of the aperture.

[0019] The washer may comprise a PCB cover portion configured to extend from the gasket restricting portion and cover a portion of the first surface of the printed circuit board. This PCB cover portion can come into contact with the first surface, e.g., to restrict a movement of the gasket in a direction away from the plane in which the first surface lies. This similarly reduces a risk that the seal, that the gasket makes with the portion of the sidewall, will be affected.

[0020] The lighting device may, in some embodiments, further comprise a second gasket positioned between the PCB cover portion and the first surface of the printed circuit board. The second gasket can serve to reduce a risk of water ingress from the first surface of the printed circuit board towards the sealed portion of the sidewall.

[0021] In some examples, the second gasket is positioned between a first PCB cover sub-portion of the PCB cover portion and the first surface of the printed circuit board; and the PCB cover portion further comprises a second PCB cover sub-portion configured to contact the first surface of the printed circuit board, the second PCB cover sub-portion being located between the first PCB cover sub-portion and the gasket restricting portion.

[0022] This approach provides further sealing between the PCB cover portion and the first surface of the printed circuit board, so as to reduce fluid ingress towards the gasket from the first surface of the printed circuit board. This improves the sealing performance of the sealing mechanism.

[0023] The lighting device may be configured wherein the second PCB covering subportion is configured to surround the aperture at the main surface of the printed circuit board; and the first PCB covering sub-portion is configured to surround the second PCB covering subportion. In some examples, the second gasket comprises adhesive configured to adhesively couple the washer to the first surface. This approach advantageously increases the pressure applied to the gasket by the washer, so as to improve the sealing performance of the sealing mechanism against the (sealed portion of the) side wall.

[0024] The gasket may comprise a flexible material (e.g., an elastomer) that makes (continuous) contact with the inner sidewall of the aperture. By way of example, the gasket may be an O-ring.

[0025] The washer, the inner sidewall of the aperture of the printed circuit board and the first surface of the printed circuit board may be configured to enclose the gasket therebetween. In other words, the gasket may be encapsulated (e.g., entirely) by the sealing mechanism and the printed circuit. The encapsulation may define an encapsulated volume that contains the gasket and a portion of the sidewall (e.g., a sealed portion of the sidewall). The encapsulated volume is thereby protected from water or liquid ingress,

[0026] The lighting device may further comprise a covering layer configured to cover at least a portion of the printed circuit board. The covering layer preferably comprises one or more lenses for the one or more light emitting devices, e.g., a lens for each light emitting device.

[0027] The lighting device may further comprise a third gasket configured to adhesively couple the washer to the covering layer. This increases the fluid ingress protection of the sealing mechanism.

[0028] The lighting device may further comprise a fourth gasket configured to adhesively couple the covering layer to the printed circuit board. This causes the covering layer to press against the washer to thereby increase the pressure applied by the washer to the gasket, thereby improving the sealing performance of the sealing mechanism.

[0029] The lighting device may further comprise a fifth gasket comprising an integrally formed portion of adhesive configured to adhesively couple the covering layer to both the printed circuit board and the washer. This approach reduces a likelihood of fluid ingress from a region not between the washer and the first surface of the printed circuit board to a region between the washer and the first surface of the printed circuit, thereby improving the fluid ingress protection of the sealing mechanism. This approach also causes the covering layer to press against the washer to thereby increase the pressure applied by the washer to the gasket, thereby improving the sealing performance of the sealing mechanism.

[0030] If present, the third, fourth and fifth gasket may be formed from a uniform, integrally formed portion of adhesive. In some examples, the lighting device comprises a plurality of apertures together with a corresponding plurality of sealing mechanisms. Each sealing mechanism may be positioned and / or configured to he in and / or around a corresponding aperture. Each sealing mechanism may be embodied as previously described.

[0031] There is also proposed a luminaire comprising any herein described lighting device and a lighting installation comprising one or more luminaires and / or one or more lighting devices.

[0032] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

[0033] BRIEF DESCRIPTION OF THE DRAWINGS

[0034] For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

[0035] Figure 1 illustrates a proposed lighting device;

[0036] Figure 2 illustrates a cross-section of a portion of the proposed lighting device;

[0037] Figure 3 illustrates another cross-section of a portion of the proposed lighting device;

[0038] Figure 4 provides an exploded view of a portion of the proposed lighting device;

[0039] Figure 5 provides a side view of a sealing mechanism for a proposed lighting device;

[0040] Figure 6 provides a cross-sectional view of the sealing mechanism for a proposed lighting device;

[0041] Figure 7 provides an exploded view of the sealing mechanism for a proposed lighting device;

[0042] Figure 8 provides a first view of a washer for use in the sealing mechanism; and Figure 9 provides a second view of the washer for use in the sealing mechanism.

[0043] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] The invention will be described with reference to the Figures.

[0045] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems and methods of the present invention will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

[0046] The invention provides a lighting device having a printed circuit board with an aperture. A sealing mechanism is used to seal at least a portion of the sidewall of the aperture from fluid ingress. A washer of the sealing mechanism has a protruding portion that extends into the aperture and presses a gasket against a portion of the sidewall of the aperture, to thereby seal said portion. The protruding portion engages or secures to the sidewall using an interference fit in order to provide the force for pressing the gasket.

[0047] Figure 1 illustrates a lighting device 100 in which proposed embodiments can be employed, for improved contextual understanding. The lighting device 100 comprises a printed circuit board 110 and a covering layer 120 that covers a first surface of the printed circuit board 110.

[0048] Examples of printed circuit boards (PCBs) are well known in the art, and include multilayer printed circuit boards (i.e., PCBs comprising a plurality of layers). One example of a multiplayer PCB is a MCPCB (metal core PCB), comprising a stack of layers comprising: a first insulator layer, a (copper) track layer; a second insulator layer and an aluminum core or aluminum layer. Other examples of multilayer PCBs are known in the art.

[0049] The printed circuit board 110 may support one or more light emitting elements (not visible in Figure 1), such as LEDs or LED arrangements. Thus, the lighting device may comprise one or more LEDs or LED arrangements supported by the printed circuit board.

[0050] The covering layer 120 may comprise a lens 125 for each light emitting element, e.g., to control the direction of a beam of light output by the corresponding light emitting element.

[0051] To facilitate coupling of the printed circuit board 110 to another element or surface, e.g., a heatsink for thermal dissipation, the printed circuit board 110 comprises one or more apertures 115 that extend through the printed circuit board from the first surface to a second, opposite surface. An alternative label for an aperture is therefore a through-hole. A screw or other fixture (e.g., clip) may extend through this hole and engage with the lighting device 100 to secure the lighting device, and therefore printed circuit board 110, to another element or surface, such as a heatsink or a surface of a luminaire. The covering layer 120 may comprise similarly positioned and structured apertures.

[0052] The covering layer may be formed of any suitable material, e.g., an optically transmissive material such as plastic or glass.

[0053] The existence of the aperture(s) means that there is an increased risk of fluid ingress to elements of the printed circuit board, particularly between any layers of the printed circuit board. The present disclosure proposes an approach for reducing this risk. More particularly, the present disclosure provides a sealing mechanism for each aperture of the printed circuit board that can be employed to improve fluid ingress protection.

[0054] The printed circuit board may comprise one or more apertures, e.g., a plurality of apertures. A hereafter described sealing mechanism may be provided for each aperture.

[0055] Figure 2 is a cross-sectional view of a portion of the lighting device 100 illustrating a proposed sealing mechanism 200. Figure 3 provides an enlarged view of a portion of the proposed sealing mechanism 200.

[0056] As previously explained, the lighting device 100 comprises a printed circuit board 110 having a first surface 111 and a second surface 112. An aperture 115 of the printed circuit board extends from the first surface 111 to the second surface 112, i.e., through the printed circuit board. Aperture 115 has or defines an inner sidewall 116. In the illustrated example, the aperture 115 has a circular cross-sectional shape. However, the aperture may have a different cross-sectional shape.

[0057] It will be appreciated that the printed circuit board 110 may be a multilayer printed circuit board, i.e., may comprise a plurality of layers. In such circumstances, the aperture 115 will expose boundaries between the plurality of layers at the aperture, and more particularly, at the inner sidewall 116 of the aperture. The proposed approach provides a mechanism for sealing at the inner sidewall 116 of the aperture, e.g., to facilitate protection of fluid ingress between any layers of the printed circuit board.

[0058] The sealing mechanism 200 comprises a gasket 210 and a washer 220.

[0059] The gasket 210 is positioned to contact the inner sidewall 116 of the aperture 115. In particular, the gasket 210 may entirely encircle or make continuous contact with the inner sidewall 116 of the aperture 115. In the illustrated example, the gasket 210 is made of a flexible material (e.g., an elastomer) that makes continuous contact with the inner sidewall 116 of the aperture 115. In particular, the gasket 210 may be formed of a flexible, but non-adhesive, material, such as a rubber, elastic material, thermoelastic material, thermoset material or thermoplastic material. For instance, the gasket 210 may be formed from a (e.g., high temperature resistant) fluorine rubber, an example of a thermoset elastomer. For example, the gasket 210 may be a ring, e.g., an O-ring, although the gasket may take other shapes for non- cylindrical apertures 115.

[0060] The washer 220 comprises a protruding portion 225 that extends into the aperture 115. The protruding portion 225 is configured to engage with the inner sidewall 116 of the aperture using an interference fit, also known as a press fit or friction fit. This may take place at an interference fit location 225 A. The protruding portion is also configured to, by way of the interference fit, contact the gasket 210 and squeeze the gasket 210 between the washer 220 and the inner sidewall 116. Thus, the protruding portion 225, as a result of the interference fit, applies a pressure to the gasket 210 in a direction towards the inner sidewall, so as to press the gasket 210 against the inner sidewall.

[0061] This approach provides a mechanism for sealing at least a portion of the inner sidewall against fluid ingress via the aperture. This significantly reduces a risk of fluid ingress disrupting the printed circuit board or components carried by the PCB.

[0062] Put another way, the configuration of the protruding portion 225 and the gasket 210 is configured to press the gasket 210 against a portion of the inner sidewall 116 of the aperture 115. This prevents or reduces a fluid flow or ingress towards said portion of the inner side wall 116. This portion of the inner sidewall 116 can be referred to as a sealed portion of the inner sidewall, as the portion is sealed from fluid ingress by the gasket 210 as it is pressed against the inner sidewall.

[0063] In particular, a portion of the surface of the protruding portion may have a shape that matches or complements the inner sidewall of the aperture. This approach facilitates a tight squeeze or fitting of the gasket between the washer and the inner sidewall of the aperture.

[0064] If the PCB is a multilayer PCB, then the gasket 210 is preferably positioned to contact or press against at least one boundary between layers of the PCB at the inner sidewall 116 of the aperture. In particular, the gasket 210 may cover the (otherwise exposed) portion of at least one layer of the PCB at the inner sidewall of the aperture. This reduces a risk of ingress of fluid between the layers of the PCB. Thus, the sealed portion of the inner sidewall 116 may comprise one or more locations on the inner sidewall where an interface or boundary between two layers of the PCB would otherwise be exposed to the aperture.

[0065] In particular examples, if the PCB is a metal core PCB, then the gasket 210 is preferably pressed against the metal core layer of the metal core PCB, e.g., a portion of the metal core layer of the metal core PCB exposed at the inner sidewall. More particularly, the gasket 210 may be positioned so as to cover any interface (at the inner sidewall of the aperture) between the metal core layer and any other layer of the PCB.

[0066] The protruding portion 225A may have a shape that complements, e.g., is the same as, the shape of the aperture 115. Preferably, the value of at least one dimension (e.g., a width or length) of the protruding portion in a plane parallel to the first surface 111 of the printed circuit board is a little or slightly greater than the value of the same dimension(s) of the aperture 115 in the same plane. This ensures an interference fit is achieved.

[0067] By way of example, in a plane parallel to the first surface 111, the aperture 115 may have a circular cross-sectional shape and the protruding portion 225A may have an annular cross-sectional shape. The diameter of this annular cross-sectional shape of the protruding portion 225 A may be a little or slightly greater than the diameter of the circular cross-sectional shape of the aperture 115.

[0068] The washer 220 may further comprise a gasket restricting portion 226. The gasket restricting portion 226 extends from the protruding portion 225 and over at least a portion of the gasket so as to restrict a movement of the gasket in a direction away from the aperture. In particular, the gasket restricting portion 226 is configured to restrict or prevent a movement of the gasket in a direction away from the interference fit location 225A.

[0069] The gasket restricting portion 226 may make contact with the first surface 111 of the printed circuit board 110. In this way, the washer 220 may entirely enclose the gasket 210 between itself and the printed circuit board 110. In particular, the gasket restricting portion 226, the protruding portion 225, inner sidewall 116 and (optionally) first surface 111 of the printed circuit board may together enclose and / or encapsulate the gasket 210.

[0070] The washer 220 may further comprise a PCB cover portion 221, 222 that is configured to extend from the gasket restricting portion 226 and cover a portion of the first surface 111 of the printed circuit board 110. In particular, the PCB cover portion may extend away from the aperture over the first surface 111 of the printed circuit board, e.g., in directions generally perpendicular to a direction of the protruding portion 225.

[0071] The PCB cover portion 221, 222 may comprise a first PCB cover sub-portion 221 (i.e., a first sub-portion). The first sub-portion is coupled to the first surface 111 of the printed circuit board 110 via a second gasket 230.

[0072] The second gasket 230 may comprise a sealing material, such as silicon gel or epoxy glue. In such embodiments, the interference fit of the protruding portion may be further configured such that the first PCB cover sub-portion 221 squeezes the second gasket 230 against the first surface 111 of the printed circuit board 110. This reduces a risk of ingress of any fluid at the first surface towards the gasket 210, e.g., and thereby towards the sealed portion of the sidewall 116 of the aperture 115.

[0073] In another example, the second gasket comprises an adhesive that adhesively couples the washer 200 to the first surface 111. The adhesive acts to both improve the engagement of the washer with the printed circuit board, e.g., provide a stronger coupling to reduce a risk of movement - which could result in fluid ingress, and as a barrier to fluid ingress from the first surface 111.

[0074] In particular, the interference fit of the protruding portion and the adhesive force provided by a second gasket formed from an adhesive together combine to increase the pressure of the gasket 210 against the sidewall 116 of the aperture 115. This aids in preventing fluid seeping or flowing past the gasket along the sidewall, e.g., reducing a fluid flow through the aperture and / or between layers of the printed circuit board (when the gasket 210 is positioned against any such boundaries).

[0075] The first sub-portion 221 is thereby effectively raised with respect to the first surface 111 of the printed circuit board 110. This leaves a space for the gasket, e.g., glue, to be positioned therebetween.

[0076] The PCB cover portion 221, 222 may further comprise a second PCB cover subportion 222 (i.e., a second sub-portion). The second sub-portion 222 directly contacts the first surface 111 of the printed circuit board. The second sub-portion is located between the aperture 115 and the first sub-portion 221. The use of the second sub-portion 222 further improves the mechanical strength of the washer because the concave / convex shape of the sub-portions 221, 222 makes the cover portion more rigid than a sub-portion having a flat shape.

[0077] The second sub-portion 222 may surround the aperture at / on the main surface 111 of the printed circuit board 110. The first sub-portion 221 may surround the second subportion 222.

[0078] Figure 2 also illustrates how the aperture 115 is configured to allow the passage of a fixing device 290, e.g., a screw, therethrough. The fixing device is configured to engage with the printed circuit board and / or washer to secure the printed lighting device to an external component or surface.

[0079] In particular examples, the fixing device 290 engages with the washer 220 to secure the printed lighting device to an external component or surface. This reduces a likelihood that the washer will shift position, e.g., fall out of the aperture 115, and thereby increases a sealing success of the sealing mechanism. The fixing device 290 may, for instance, comprise a screw. The screw may comprise a head portion 291 configured to engage with the washer (and / or printed circuit board). The screw may also comprise a screw fitting configured to pass through the washer and the aperture of the printed circuit board for securing the lighting device to an external surface or component. Use of a screw is particularly advantageous, as the screw will (when securing to an external component or surface) directly press on the washer to increase the sealing effect of the sealing mechanism.

[0080] The washer 220 may be formed from any suitable material for ingress protection, such as a stainless steel or plastic. In particular, the washer 220 may be made of a spring-like (elastic) material so that the washer can be manipulated to be inserted into the aperture and apply pressure to the gasket 210.

[0081] Further fluid ingress protection can be achieved using the covering layer 120.

[0082] As previously mentioned, the covering layer is configured to cover (a portion of) the first surface of the printed circuit board 110.

[0083] In particular, the lighting device may further comprise a third gasket 252 positioned between the washer 220 and the covering layer 120. The third gasket is able to prevent or reduce fluid ingress from the aperture to the first surface 111 of the printed circuit board 110 (or vice versa). Preferably, the third gasket does not directly contact the printed circuit board 110.

[0084] The third gasket may comprise an adhesive, such as a sealing glue / paste, for adhesively coupling the washer to the covering layer. This approach also helps to increase the force applied by the washer to the gasket 210, to further improve the sealing by the sealing mechanism.

[0085] The lighting device may further comprise a fourth gasket 253 positioned between the covering layer 120 and the (first surface 111 of the) printed circuit board 110. The fourth gasket may be positioned proximate or adjacent to the washer, e.g., to surround the washer. The fourth gasket is similarly able to prevent or reduce fluid ingress from the aperture to the first surface 111 of the printed circuit board 110 (or vice versa). Preferably, the fourth gasket does not directly contact the washer.

[0086] In some examples, the fourth gasket comprises adhesive, such as a sealing glue / paste, for adhesively coupling the covering layer to the (first surface 111 of the) printed circuit board 110. This advantageously increases the force applied by the washer to the gasket (via other parts of the covering layer 120). The lighting device 100 may comprise a fifth gasket 254 comprising an integrally formed portion of adhesive, such as a sealing glue / paste, configured to adhesively couple the covering layer 120 to both the printed circuit board 110 and the washer 220. Thus, a single piece of adhesive covers the bounds between the edge of the washer 220 and the printed circuit board 110. This reduces or prevents fluid flow from the printed circuit board to beneath the washer (e.g., towards the gasket).

[0087] In a typical embodiment, the third, fourth and / or fifth gasket(s) may be formed from an adhesive, such as a (thermal) melt adhesive or a sealing glue / paste such as a silicon gel or an epoxy. However, in alternative embodiments to those disclosed above, the third, fourth and / or fifth gasket (where present) may comprise a flexible material, such as an elastomer or thermoplastic.

[0088] The third, fourth and / or fifth gasket may be held in place by the covering layer 120 being secured to the washer 220 and / or printed circuit board 110, e.g., by the fixing device 290. Alternatively and / or additionally, the third, fourth and / or fifth gasket may itself / themselves hold the covering layer 120 to the washer and / or printed circuit board, e.g., using an adhesive force (i.e., by being formed of adhesive),

[0089] In practice, if all of the third, fourth and fifth gaskets are present, then they may be formed of a single, uniform piece of material. In particular, they may be formed from a single adhesive layer. The covering layer 120 may comprise a groove for each of the third, fourth and fifth gaskets, which groove is filled with adhesive after which the covering layer is pressed against the washer 220 and printed circuit board 110 so as to adhere the covering layer thereto. In this way, the third, fourth and fifth gaskets may effectively form a single gasket that couples the covering layer 120 to the washer 220 and the printed circuit board.

[0090] Figure 2 also illustrates the relative position of a light emitting element 299 with respect to a lens 125 of a covering layer 120.

[0091] Figure 4 provides an exploded view of a portion of the lighting device 100, to more clearly demonstrate the various feature previously described.

[0092] Figure 4 also aids in the understanding of how the third, fourth and fifth gaskets may be formed in an embodiment. In particular, a series of grooves 410 may be defined in the covering layer 120. Each groove may define the shape and / or position of a respective one of the third, fourth and fifth gaskets. The grooves 410 may then be filled with a sealing glue or paste (such as a silicon gel). The covering layer 120 may then be pressed or pushed against the printed circuit board 110 and washer 220. The sealing glue / paste then cures to create the gaskets 252, 253, 254. Figure 5 illustrates a side view of a proposed sealing mechanism. Figure 6 provides a cross-sectional view of the proposed sealing mechanism. Figure 7 provides an exploded view of the proposed sealing mechanism. These figures more clearly demonstrate the structure of a proposed sealing mechanism, particularly the protruding portion 225.

[0093] As illustrated in Figure 7, the gasket 210 may have a thickness t. Preferably, the thickness t of the gasket is sufficient to cover, from the inner sidewall of the aperture, at least one or more humidity sensitive layers of the printed circuit board (if present). In particular, the gasket may be sized and positioned to cover an interface or boundary of each humidity sensitive layer at the inner sidewall of the aperture, so as to prevent or reduce a fluid ingress between layers of the printed circuit board.

[0094] Figure 8 provides an upper view of the washer 220, whilst Figure 9 provides a lower view of the washer 220. These figures more clearly demonstrate the structure of the subportions of the washer 220.

[0095] Although not illustrated or described in detail, it will be apparent that the printed circuit board may carry connecting circuitry (e.g., conductors) and / or carry one or more other electrical components. Such configurations are well known in the art.

[0096] There is also proposed a luminaire comprising one or more lighting devices as herein disclosed. The luminaire may comprise additional components, e.g., driving circuitry, one or more mounts, one or more housings, sensing circuitry, monitoring circuitry, control circuitry and so on.

[0097] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0098] 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.

[0099] If the term "adapted to" is used in the claims or description, it is noted the term "adapted to" is intended to be equivalent to the term "configured to". If the term "arrangement" is used in the claims or description, it is noted the term "arrangement" is intended to be equivalent to the term "system", and vice versa.

[0100] Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS:

1. A lighting device (100) comprising: a printed circuit board (110) configured to support one or more light emitting devices (299), wherein the printed circuit board comprises an aperture (115) passing from a first surface (111) to a second surface (112), the aperture having an inner sidewall (116); and a sealing mechanism (200) comprising: a gasket (210) positioned to contact the inner sidewall (116) of the aperture (115) of the printed circuit board (110); and a washer (220) comprising a protruding portion (225) that extends into the aperture (115), wherein the protruding portion is configured to engage with the inner sidewall (116) of the aperture using an interference fit and squeeze the gasket (210) between the washer and the inner sidewall (116) of the aperture (115); wherein the lighting device (100) further comprises a screw (290) comprising: a head portion (291) configured to engage with the washer; and a screw fitting (292) configured to pass through the washer and the aperture of the printed circuit board for securing the lighting device (100) to an external surface or component.

2. The lighting device (100) of claim 1, wherein: the printed circuit board comprises a plurality of layers comprising at least one humidity-sensitive layer; and the gasket (210) has a thickness (t) sufficient to cover at least the at least one humidity-sensitive layer from the inner sidewall (116) of the aperture (115).

3. The lighting device (100) of claim 1 or 2, wherein the washer (220) comprises a gasket restricting portion (226) that extends from the protruding portion and over at least a portion of the gasket so as to restrict a movement of the gasket in a direction away from the aperture.

4. The lighting device of claim 3, wherein the washer comprises a PCB cover portion (221, 222) configured to extend from the gasket restricting portion and cover a portion of the first surface (111) of the printed circuit board.

5. The lighting device of claim 4, further comprising a second gasket positioned between the PCB cover portion (221, 222) and the first surface (111) of the printed circuit board.

6. The lighting device of claim 5, wherein: the second gasket is positioned between a first PCB cover sub-portion (221) of the PCB cover portion and the first surface (111) of the printed circuit board (110); and the PCB cover portion further comprises a second PCB cover sub-portion (222) configured to contact the first surface (111) of the printed circuit board, the second PCB cover sub-portion being located between the first PCB cover sub-portion and the gasket restricting portion (226).

7. The lighting device of claim 6, wherein: the second PCB covering sub-portion is configured to surround the aperture at the main surface of the printed circuit board; and the first PCB covering sub-portion is configured to surround the second PCB covering sub-portion.

8. The lighting device (100) of any of claims 5 to 7, wherein the second gasket comprises adhesive configured to adhesively couple the washer (200) to the first surface (111)9. The lighting device (100) of any of claims 1 to 8, wherein the gasket (210) is an O-ring.

10. The lighting device (100) of any of claims 1 to 9, wherein the washer (220), the inner sidewall (116) of the aperture (115) of the printed circuit board (110) and the first surface (111) of the printed circuit board (100) are configured to enclose the gasket therebetween.

11. The lighting device (100) of any of claims 1 to 10, further comprising a covering layer (120) configured to cover at least a portion of the printed circuit board.

12. The lighting device (100) of claim 11, further comprising a third gasket (252) configured to adhesively couple the washer to the covering layer.

13. The lighting device (100) of any of claims 11 or 12, further comprising a fourth gasket (253) configured to adhesively couple the covering layer to the printed circuit board.

14. The lighting device (100) of any of claims 11 to 13, further comprising a fifth gasket (254) comprising an integrally formed portion of adhesive configured to adhesively couple the covering layer to both the printed circuit board and the washer.

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