A lighting device

Abstract

A lighting device (100) for illuminating a surface (195). The lighting devices has a tubular housing (110) with a first side portion (111), for facing the surface (195) to be illuminated, and a second side portion (112), for facing away from the surface (195) to be illuminated. The tubular housing (110) has linear arrays of LED arrangements (431, 432) that each emit light, a first part (LI) of which is projected out of the first side portion (111) and a second part (L2) of which is leaked out of the second side portion (112). The second part (L2) is light that is leaked as a result of projecting the first part (LI) of the light.

Description

[0001] 2024PF80453

[0002] A lighting device

[0003] FIELD OF THE INVENTION

[0004] The present invention relates to the field of artificial lighting, and in particular to lighting devices for illuminating a surface.

[0005] BACKGROUND OF THE INVENTION

[0006] There is an increasing reliance upon artificial lighting worldwide. One form of lighting device for use in providing artificial lighting is designed for illuminating a surface. Examples of this type of lighting device include wall washers.

[0007] One form of this type of lighting device is a freestanding lighting device, which comprises a stand and a tubular housing. One or more linear arrays of LED arrangements are mounted in the tubular housing and are positioned to, when activated, illuminate a surface faced by the freestanding lighting device. This provides a wall wash effect.

[0008] There is an ongoing desire to reduce the visual impact of a lighting device, particularly to reduce a perceived blocking of light produced by the lighting device.

[0009] SUMMARY OF THE INVENTION

[0010] The invention is defined by the claims.

[0011] According to examples in accordance with an aspect of the invention, there is provided a lighting device for positioning on a planar surface.

[0012] The lighting device comprises: a tubular housing configured to extend, when the lighting device is positioned on the planar surface, in a first direction substantially perpendicular to the planar surface, wherein the tubular housing comprises: a first light exit window on a first side portion of the tubular housing; and a second light exit window on a second side portion of the tubular housing, wherein the first side portion is adapted to face towards a second surface, and the second side portion is adapted to face away from the second surface and towards an observer; wherein the second surface is substantially perpendicular to the planar surface; linear arrays of LED arrangements positioned in the tubular housing, wherein each LED arrangement is configured to output light having a controllable color and each linear array extends parallel to the first direction.2024PF80453

[0013] 2

[0014] Each LED arrangement is configured to: project a first part of the light output by said LED arrangement out of the first light exit window of the tubular housing towards the second surface; and leak a second part of the light output by said LED arrangement out of the second light exit window of the tubular housing, wherein the second part is leakage light resulting from the projecting of the first part of the output light.

[0015] The present disclosure proposes a lighting device mountable on a planar / first surface. The lighting device comprises LED arrangements, for which a first part of light emitted by each LED arrangement is projected out of a first side portion of a tubular housing and a second part of light (specifically: leakage light) is leaked out of a second side portion of the tubular housing. In practice, the light projected out of the first side portion is designed for illuminating a second surface. When in use, the first side portion is adapted to face the second surface, whereas the second side portion is adapted to face away from the second surface.

[0016] The intentional leakage of some light out of the second side portion reduces a perceived profile of the lighting device. In particular, this leakage of emitted light functions to smooth a contrast between the lighting device and the illuminated second surface, which smoothing is synchronous with the color of the illumination and exploits the same light sources (thereby saving power and / or material resource).

[0017] In some examples, the linear arrays comprises: a first linear array, wherein each LED arrangement of the first linear array is configured to project the first part of light output by said LED arrangement in a direction parallel to a first projection direction; and a second linear array, wherein each LED arrangement of the second linear array is configured to project the first part of the output light in a direction parallel to a second projection direction, wherein the second projection direction makes a non-zero angle with respect to the first projection direction.

[0018] This provides a mechanism for producing multiple patches of light upon the second surface, for improved and more precise control over the illumination of the second surface. In particular, this mechanism facilitates a change in color in a horizontal direction, when the planar surface is a horizontal surface.

[0019] In some examples, a smallest angle between the first projection direction and the second projection direction is less than 180°. In some examples, the first projection direction and the second projection direction are substantially perpendicular to the first direction.

[0020] In some examples, for each linear array of LED arrangements, the tubular housing defines a respective first optical cavity and each LED arrangement of the linear array2024PF80453

[0021] 3

[0022] projects light out of the first light exit window through said first optical cavity; the LED tubular housing defines a second optical cavity optically connected to each first optical cavity; and for each LED arrangement of each linear array, the second part of the light output by the LED arrangement is light that leaks from the first optical cavity of the respective first optical cavity of said linear array into the second optical cavity.

[0023] This provides a mechanism by which some of the light projected to form the first part of light is able to leak out of the second light exit window. The second optical cavity also facilitates, where appropriate, the mixing of light from different LED arrangements, to thereby further reduce a contrast between light illuminating the second surface and light output from the second side portion.

[0024] In some examples, the first optical cavity and the second optical cavity are optically connected together by a translucent or transparent portion of a divider for securing the linear arrays of LED arrangements to the tubular housing. This provides a mechanism that simultaneously provides mechanical support to the tubular housing as well as optically connecting different optical cavities to one another.

[0025] In some examples, where present, the first optical cavity for the first linear array is not directly optically connected to the first optical cavity for the second linear array. This reduces a risk of color mixing between the first part of light projected by each linear array for more precise control over the illumination of a second surface.

[0026] In some examples, the second light exit window comprises a diffuser for diffusing the second part of light received from each LED arrangement. This approach results in the second part of the light emitted out of the second light exit window being more diffuse and / or dispersed. This improves the masking of the lighting device (i.e., reduces a contrast between the appearance of the lighting device and the illuminated second surface) and reduces a glare to an observer of the lighting device (and second surface).

[0027] In some examples, for each linear array, the LED arrangements are spaced apart by a distance of between 5 mm and 30 mm. This helps produce a uniform spread of light upon the second surface.

[0028] In some examples, for each LED arrangement, the first part of the light output by the LED arrangement comprises no less than 60% of the light output by the LED arrangement. This approach ensures higher intensity illumination of the second surface, e.g., reducing wasted energy, whilst also reducing a glare perceived by an observer of the lighting device (and second surface).2024PF80453

[0029] 4

[0030] In some examples, for each LED arrangement, the first part of the light output by the LED arrangement comprises no less than three times (e.g., no less than four times) the amount of light in the second part of the light output by the LED arrangement. This provides a more efficient lighting device.

[0031] In some examples, the tubular housing has a rounded cross-sectional shape along its length. For instance, the tubular housing may have a circular, elliptical, oval or otherwise curved cross-sectional shape along its length. This approach reduces a risk of unexpected or uncontrollable scattering of light at comers or vertices, thereby further reducing a contrast between the lighting device and the illuminated (second) surface.

[0032] In some examples, the tubular housing is formed of transparent or translucent material.

[0033] In some examples, the second part of light output by each LED arrangement is light generated by said LED arrangement that is reflected and / or scattered by the first light exit window, e.g., and no other light. This approach repurposes light that would otherwise not be projected through the first light exit window to instead be emitted or leaked through the second light exit window.

[0034] In some examples, the planar surface is a horizontal surface, such that the first direction extends vertically. In such examples, the lighting device may further comprise a stand for positioning the light device on the planar surface.

[0035] The lighting device may further comprise a control unit and / or a sensor configured to control the color of light output by each LED arrangement.

[0036] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment s) described hereinafter.

[0037] WO 2025036751 Al discloses a light generating system, configured to generate system light; wherein the light generating system comprises a tubular light generating device, a tubular optical element, and a device support.

[0038] BRIEF DESCRIPTION OF THE DRAWINGS

[0039] 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:

[0040] Figure 1 provides a first view of a proposed lighting device;

[0041] Figure 2 provides a second view of the proposed lighting device;

[0042] Figure 3 is a cross-sectional view of one version of the proposed lighting device;2024PF80453

[0043] 5

[0044] Figure 4 is a cross-sectional view of another version of the proposed lighting device;

[0045] Figure 5 provides a partially exploded view of the proposed lighting device; Figure 6 provides a view of the proposed lighting device with an alternative stand;

[0046] Figure 7 provides another view of the proposed lighting device; and Figure 8 illustrates further optional elements of the proposed lighting device.

[0047] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0048] The invention will be described with reference to the Figures.

[0049] 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.

[0050] The present disclosure provides a lighting device for illuminating a surface. The lighting devices has a tubular housing with a first side portion, for facing the surface to be illuminated, and a second side portion, for facing away from the surface to be illuminated. The tubular housing has linear arrays of LED arrangements that each emit light, a first part of which is projected out of the first side portion and a second part of which is leaked out of the second side portion. The second part is light that is leaked as a result of the projecting the first part of the light.

[0051] Figures 1 and 2 illustrate a use-case scenario for a proposed lighting device 100, for improved contextual understanding.

[0052] The lighting device 100 is designed for positioning on a planar surface 190, e.g., a floor. The intent of the lighting device is to illuminate a second surface 195, such as a wall, with light L. The second surface 195 may be substantially perpendicular to the planar surface 190, but this is not essential.2024PF80453

[0053] 6

[0054] The lighting device 100 comprises a tubular housing 110 that generally extends in a first direction Yl, which is substantially perpendicular to the planar surface 190 (when the lighting device 100 is positioned thereon).

[0055] As illustrated in Figure 1, the tubular housing 110 has a first side portion 111 for facing the second surface 195 and a second side portion 112 that, when the first side portion 111 faces the second surface, faces away from the second surface. Thus, the first side portion 111 acts or functions as a front of the tubular housing, with the second side portion acting or functioning as a rear of the tubular housing.

[0056] As later described in further detail, the tubular housing 110 comprises linear arrays of LED arrangements for generating the light L for illuminating the second surface 195. The linear array(s) of LED arrangements are thereby configured to emit light out of the first side portion 111 of the lighting device for illuminating the second surface 195 with light.

[0057] The lighting device 100 may also comprise a stand 120 for mounting or supporting the lighting device 100 on the planar surface 190. In this way, the lighting device 100 may be a freestanding lighting device 100. However, in other examples, the stand is replaced by another form of mounting element, such as a screw-based mounting element or the like.

[0058] In the illustrated example, the stand takes a conical or frustum shape, which (in use) tapers with increased distance from the planar surface 190. This shape reduces the risk of the lighting device 100 tipping or falling over, by effectively keeping the center of gravity of the lighting device 100, when in use, closer to the planar surface. However, over suitable shapes for a stand 120 will be apparent to the skilled person, and some examples are later described.

[0059] With specific reference to Figure 2, the lighting device 100 may comprise two or more linear arrays of LED arrangements, each designed to generate light PAI, PA2 having a controllable color.

[0060] The LED arrangements of each linear array may be arranged to output light from the first side portion 111 and into a volume for its respective linear array, to thereby (if positioned adjacent to the second surface) illuminate different portions or patches PAI, PA2 of the second surface.

[0061] In the example illustrated by Figure 2, the lighting device comprises only two linear arrays of LED arrangements, and each LED arrangement in a same linear array is here controlled to emit light of a same color (with different linear arrays emitting light of different colors). In this way, a first linear array produces a first patch PAI of light and the second linear array produces a second patch PA2 of light.2024PF80453

[0062] 7

[0063] However, embodiments are not limited thereto. In some examples, the lighting device 100 may comprise a single linear array of LED arrangements or more than two linear arrays of LED arrangements.

[0064] Moreover, in some examples, LED arrangements on a same linear array may be controlled to emit light of different colors. This will effectively subdivide each patch / portion of light PAI, PA2 into different sub-portions or sub-patches, to provide more granular control over the illumination of the second surface. This provides vertical control over the color of the second surface.

[0065] Put more generally, each LED arrangement is configured to output light from the first side portion 111 into a respective sub-volume. Each sub-volume will, if the lighting device is positioned proximate to the second surface, illuminate different sub-portions or subpatches of the second surface. LED arrangements belonging to a same linear array will contribute to the illumination of a same patch PAI, PA2 on the second surface.

[0066] A working example of illuminating sub-patches is provided later in this disclosure.

[0067] Example LED arrangements are well known to the skilled person, and typically comprise a plurality of LEDs each configured to, when powered, emit light. Each LED arrangement has a controllable color. This can be achieved by forming the LED arrangement from three or more LED strings of different colors (e.g., in an RGB array or a RGBW arrangement), and controlling the current flow through each LED string to thereby control a color of light emitted by the LED arrangement. Color controllable LED arrangements are well established in the art and are not further described in detail for the sake of conciseness. An LED arrangement may, for instance, comprise an LED chip package or similar.

[0068] Although not illustrated in Figures 1 and 2, it will be appreciated that the lighting device may comprise one or more other components (e.g., housed by the tubular housing) for powering and / or controlling the operation of the LED arrangements.

[0069] By way of example, the lighting device may comprise a control unit configured to control the color of light output by each LED arrangement. Thus, each LED arrangement may be separately controllable by the control unit. In other examples, different sets or subsets of LED arrangements may be controlled synchronously or simultaneously with one another.

[0070] The control unit may, for instance, be responsive to one or more control signals generated by an interface of the lighting device (e.g., a communication interface, a user interface, a remote control interface and so on).2024PF80453

[0071] 8

[0072] Of course, the lighting device may comprise driving circuitry, communication circuitry, sensing arrangements, one or more power connectors (for connecting the lamp to a power source) and / or any other suitable electronic component. These may be housed, at least partially, within the tubular housing.

[0073] The present disclosure recognizes that the profile of the lighting device 100 may block or impede the appearance of the light L, PAI, PA2 projected onto the second surface 195. In particular, at least the tubular housing 110 of the lighting device 100 will block any light reflected back from the second surface 195. This phenomenon is perhaps best illustrated by Figure 2, in which the profile of the lighting device is visible to a viewer of the second surface.

[0074] The present disclosure proposes a mechanism for at least partially addressing this problem. In particular, it is herein proposed to intentionally leak part of the light output by the LED arrangements to be emitted or leaked from the second side portion 112 of the lighting device 100. In this way, the profile of the lighting device 100 is at least partially masked by the emission of the leaked light.

[0075] The proposed approach also avoids the need for a dedicated LED arrangement for emitting light from the second side portion 112 of the lighting device 100 to achieve masking of the profile (i.e., attenuating of the perceived profile) of the lighting device. Rather, some of the light that is already emitted for illuminating the second surface is (re)routed for illuminating in a direction away from the second surface.

[0076] Figure 3 provides a cross-sectional view of one version of the proposed lighting device 100, which is taken in the plane A-B indicated in Figure 1.

[0077] As previously explained, the lighting device 100 comprises a tubular housing 110, which has a first side portion 111 and a second side portion 112. The first and second side portions face different directions (e.g., face away from one another). Conceptually, it is possible to consider a dividing plane Pl that divides the lighting device into two parts, e.g., two halves. The first side portion 111 lies entirely within a volume on one side of the dividing plane and the second side portion 112 lies entirely within a volume on the other side of the dividing plane.

[0078] The tubular housing 110 of the proposed lighting device comprises a first light exit window 311, positioned on the first side portion 111, and a second light exit window 312, positioned on the second side portion 112. Both light exit windows are configured to permit the (at least partial) transmission of light therethrough.2024PF80453

[0079] 9

[0080] The lighting device 100 also comprises at least one linear array 320 of LED arrangements 330, here: a single linear array 320. Only one LED arrangement 330 for the linear array 320 is visible in Figure 3. The linear array is housed in the tubular housing 110 and extends parallel to the first direction Y1 (Figure 1).

[0081] In the illustrated example, the linear array is positioned parallel to the hypothetical dividing plane Pl, and such that light emitted by the linear array is directed (e.g., only) away from the hypothetical dividing plane Pl and towards the first light exit window 311.

[0082] Each LED arrangement is configured to project a first part LI of the light L output by said LED arrangement out of the first light exit window 311 of the tubular housing 110, and thereby (in use) towards the second surface 195. Various exemplary rays of the first part LI of light L are labelled in Figure 3. The first part LI of the light contributes to the formation of a particular patch of light, e.g., on the second surface.

[0083] Each LED arrangement is also configured to leak a second part L2 of the light L output by said LED arrangement out of the second light exit window 312 of the tubular housing 110. More particularly, the second part L2 is leakage light resulting from the projecting of the first part LI of the output light (through the first light exit window 311).

[0084] Thus, for each linear array, the LED arrangements are configured to project light L, e.g., each centered around a respective central axis CA. At least the central axis of the projected light may be perpendicular to the first direction (although this is not essential). A first part LI of the projected light L is projected out of the first light exit window 311. A second part L2 of the projected light L is leaked out (i.e., transmitted out) of the second light exit window 312.

[0085] In the context of the present disclosure, a light exit window 311, 312 is a portion of the tubular housing through which light is able to escape the tubular housing 110. The light exit window may, in some instances, comprise an aperture of the tubular housing. However, in preferred examples, the light exit window is formed from translucent or transparent material.

[0086] By way of example only, the entirety of the tubular housing may be formed from a transparent or translucent material (such as glass or plastic).

[0087] Example mechanisms for defining the second part L2 of light, i.e., mechanisms by which the projecting of the first light LI creates leakage light that forms the second part L2 of the light, are hereafter described.

[0088] In some examples, as illustrated in Figure 3, the second part L2 may comprise a part of the light L that is scattered or reflected by the first light exit window 311. Thus, the2024PF80453

[0089] 10

[0090] first light exit window 311 may comprise a transparent or translucent material (such as glass or plastic) that partially reflects / scatters light received from the LED arrangement(s), e.g., as a natural consequence of functioning as an interface between two different materials. At least some of the partially reflected / scattered light is transmitted out of the second light exit window to form the second part L2 of the light L.

[0091] In some scenarios, each LED arrangement may be configured to project light L having a non-zero beam angle, e.g., a beam angle greater than 45°. Thus, the light L may have a defined beam spread. In such scenarios, the second part L2 of the light may include some of the light at the edge of the beam spread, e.g., light that is emitted by the LED arrangement that makes an angle (with the central axis CA of the emitted light) greater than a predetermined angle, e.g., greater than 60°. This form of light leakage may be particularly prevalent or apparent for LED arrangements that are angled with respect to the hypothetical dividing plane Pl that separates the first side portion 111 from the second side portion 112 of the lighting device, which is not illustrated by Figure 3.

[0092] In some scenarios, the second part may comprise a part of the light emitted by the LED arrangement(s) that is routed around the tubular housing 110 from the first light exit window 311 to the second light exit window 312. For instance, the tubular housing may (as illustrated) comprise a continuous or monolithic piece of translucent / transparent material, with different portions of this piece of material defining the first light exit window and the second light exit window. Some of the light emitted by the LED arrangements may propagate through this piece of material from the first light exit window to the second light exit window, and exit the lighting device therefrom.

[0093] Other mechanisms for configuring the LED arrangements and / or the tubular housing to cause at least some of the light generated by the LED arrangements to be leaked through the second light exit window will be readily apparent to the skilled person.

[0094] Preferably, for each LED arrangement, the first part of the light output by the LED arrangement comprises no less than 60%, e.g., no less than 80%, e.g., no less than 90% of the light output by the LED arrangement. This can be achieved through appropriate material selection of the first light exit window, design of the LED arrangement(s), positioning of the LED arrangement(s) and / or design of the tubular housing.

[0095] Preferably the lighting device 100 is configured such that a majority of light (e.g., >60%) emitted by each LED arrangement is directed towards the first light exit window. This can be achieved through appropriate placement of the LED arrangement and design of LED arrangement (e.g., to achieve a particular beam angle). This is useful for improved2024PF80453

[0096] 11

[0097] illumination of the second surface and to reduce a risk of glare to a viewer of the lighting device and the illuminated second surface (e.g., to a viewer standing closer to the second side portion than the first side portion - which is a typical use case for the proposed lighting device).

[0098] In some examples, for each LED arrangement, the first part of the light output by the LED arrangement comprises no less than three times (e.g., no less than four times) the amount of light in the second part of the light output by the LED arrangement. This provides a more efficient lighting device.

[0099] In particular examples, for each linear array 320 of LED arrangements, the tubular housing defines a respective first optical cavity 341. Each LED arrangement 330 of the linear array 320 projects light LI out of the first light exit window 311 through said first optical cavity 341.

[0100] Similarly, the LED tubular housing may define a second optical cavity 342 optically connected to each first optical cavity. The second part L2 of the light output by the LED arrangement may be (e.g., only) light that leaks from the first optical cavity 341 of the corresponding linear array into the second optical cavity 342.

[0101] The light in the second optical cavity may be mixed within the second optical cavity. In this way, the second part of light emitted by each LED arrangement may be mixed in the second optical cavity, which (when output) causes the emitted light to resemble a transition between the light emitted by the different linear arrays and / or LED arrangements.

[0102] In particular, each LED arrangement may be configured to only emit light into the first optical cavity 341 for its respective linear array. For instance, each LED arrangement may be positioned in the first optical cavity 341 for its respective linear array. The second part L2 of the light output by the LED arrangement may thereby only comprise light that was previously in the first optical cavity 341 and was leaked into the second optical cavity 342.

[0103] In some examples, each first optical cavity and the second optical cavity may be optically connected together by a translucent or transparent portion 350 of a divider. The divider may, for instance, lie upon and / or define the hypothetical dividing plane PL The divider may be configured to at least partially secure the linear arrays of LED arrangements to the tubular housing, e.g., provide a bracing functionality for securing the linear arrays of LED arrangements to the tubular housing.

[0104] In some examples, at least the second light exit window is a diffuser, examples of which are well known in the art. This configures the second part of the light emitted out of the second light exit window to be more diffuse, to improve the masking of the lighting device and reducing a perceived glare to an observer of the lighting device (and second surface).2024PF80453

[0105] 12

[0106] Figure 4 provides a cross-sectional view of another version of the proposed lighting device 100, which is taken in the plane A-B indicated in Figure 1.

[0107] This version differs from the previously disclosed version by comprising a plurality of linear arrays 421, 422 of LED arrangements 431, 432, namely a pair of linear arrays of LED arrangements. The linear arrays make a non-zero angle with respect to one another, so as to, in use, illuminate different patches or portions of a second surface.

[0108] As before, each LED arrangement is configured to project a first part LI, LX of the light L output by said LED arrangement out of the first light exit window 311 of the tubular housing 110, and thereby (in use) towards the second surface 195. The first part LI of the light contributes to the formation of a particular patch of light, e.g., on the second surface. In particular, the first part LI, LX of light emitted by LED arrangements of different linear arrays contributes to a different patch of light, e.g., on the second surface.

[0109] Similarly, each LED arrangement is also configured to leak a second part L2 of the light L output by said LED arrangement out of the second light exit window 312 of the tubular housing 110. The second part L2 is leakage light resulting from the projecting of the first part LI of the output light (through the first light exit window 311).

[0110] Thus, the illustrated lighting device 100 comprises a first linear array 421 and a second linear array 422.

[0111] The first and second linear arrays make a non-zero angle with respect to one another. In other words, each LED arrangement of the first linear array is configured to project the first part LI of light output by said LED arrangement in a direction parallel to a first projection direction. Similarly, each LED arrangement of the second linear array 422 is configured to project the first part LX of the output light in a direction parallel to a second projection direction. The second projection direction makes a non-zero angle (a) with respect to the first projection direction.

[0112] In this context, a projection direction is a central axis of light output by the LED arrangement, e.g., a direction in which the LED arrangement(s) are aimed. Thus, a projection direction may represent the direction along which the greatest intensity of light is emitted by the LED arrangement.

[0113] In some examples, a smallest angle a between the first projection direction and the second projection direction is less than 180°, e.g., less than or equal to 160°, e.g., less than or equal to 120°. Thus, if each projection direction is perpendicular to a respective plane in which a linear array mounting the LED arrangement lies, then a smallest angle between the2024PF80453

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[0115] linear arrays may be more than 0°, e.g., more than or equal to 20°, e.g., more than or equal to 60°.

[0116] In some examples, the smallest angle a between the first projection direction and the second projection direction is greater than or equal to 30°, e.g., greater than or equal to 40°, greater than or equal to 80°. This provides a good spread of the first part(s) of light when projected onto the second surface.

[0117] Thus, if each projection direction is perpendicular to a plane in which a linear array mounting the LED arrangement lies, then a smallest angle between the linear arrays may be less than 150°, e.g., less than or equal to 140°, e.g., less than or equal to 100°.

[0118] Thus, the smallest angle a between the first projection direction and the second projection direction may, for instance, take a value of between 40° and 120° (inclusive). A good working example for the value of the smallest angle a is 120°. Thus, if each projection direction is perpendicular to a respective plane in which a linear array mounting the LED arrangement lies, then a smallest angle between the linear arrays may be between 60° and 140°.

[0119] The first projection direction and the second projection direction may be substantially perpendicular to the first direction, i.e., substantially perpendicular to the respective plane in which each linear array lies.

[0120] It has previously been described how each linear array may have a corresponding first optical cavity 441 A, 441B. In other words, the tubular housing may define a respective first optical cavity for each linear array, and each LED arrangement of (each) linear array may be configured to project light out of the first light exit window through said first optical cavity, e.g., project all light into the corresponding first optical cavity.

[0121] In the illustrated example, each first optical cavity 441A, 441B is independent from each other first optical cavity. In other words, the first optical cavities are not directly optically connected to one another, such that light is not able to pass directly between the first optical cavities. Thus, the first optical cavity 441 A for the first linear array 421 is not directly optically connected to the first optical cavity 44 IB for the second linear array 422. This does not exclude the possibility of some light passing from one first optical cavity 441 A to another first optical cavity 44 IB via the second optical cavity 442 and / or via another element (such as the tubular housing).

[0122] This approach reduces a risk of mixing light before emission from the first side portion 111 of the tubular housing 110, which facilitates more precise control over the projection of light onto the second surface.2024PF80453

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[0124] It will be appreciated that, in such examples, the first light exit window 411 may be conceptually divided into a respective sub-window for each first light optical cavity.

[0125] In other examples, the first optical cavity of more than one linear array may be optically connected to one another, e.g., defining a same optical cavity. This facilitates lighting mixing within the lighting device, which may provide a smoother transition of light between different patches or regions (of the second surface) illuminated by the lighting device 100.

[0126] The linear array(s) 421, 422 may be mounted on or supported by a supporting structure 460. The supporting structure may extend along in the first direction Y1 (Figure 1) and support one or more other components of the lighting device, including at least the linear array. The supporting structure may be configured to, in some embodiments, optically separate different first optical cavities from one another, such that the first optical cavities are not directly optically connected to one another.

[0127] The lighting device may again comprise a divider having one or more translucent or transparent portions 450 that separate the first optical cavity / cavities 441 A, 441B from the second optical cavity 442. The divider may, for instance, lie upon and / or define the hypothetical dividing plane Pl. The divider may be formed as part of the supporting structure 460 or be supported by the supporting structure 460.

[0128] In some examples, such as those illustrated by Figures 3 and 4, the tubular housing has a rounded cross-sectional shape along its length. For instance, the tubular housing may have a circular or elliptical cross-sectional shape along its length. Thus, the tubular housing may be generally cylindrical. This provides a good distribution of light out from the lighting device, as well as reducing a risk of expected light scattering and / or refracting (e.g., at corners of the tubular housing).

[0129] In any above described embodiment, the tubular housing may be a continuous, monolithic piece of material. This further reduces a visual impact of the lighting device 100.

[0130] That being said, in other examples, the tubular housing need not be a continuous, monolithic piece of material, but may comprise different sections connected to form a tube, e.g., one or more sections defining the first light exit window and one or more sections defining the second light exit window.

[0131] Figure 5 provides an exploded view of a portion of a proposed lighting device 100, which comprises two linear arrays 421, 422 of LED arrangements 431, 531, 432, 532.

[0132] Figure 5 illustrates how each linear array 421, 422 extends parallel to the first direction Y 1.2024PF80453

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[0134] In some examples, for each linear array, the LED arrangements are spaced apart by a distance DI of between 5 mm and 30 mm, e.g., 10 mm. This provides a good spread of light emitted by the lighting device.

[0135] Figure 6 provides a view of a lighting device 100 with a variant base 620. The base 620 here instead comprises a dish-shaped portion or disc-shaped portion for contacting the ground surface. This provides a large floor contact area for reducing a risk of the lighting device toppling or falling.

[0136] Figure 7 provides another view of the lighting device 100.

[0137] It has previously been explained how the lighting device may comprise a plurality of linear arrays, e.g., two linear arrays, of LED arrangements.

[0138] In some examples, the color and / or intensity of each LED arrangement (in each linear array) is separably controllable, e.g., by a control unit. This facilitates the control of the color and / or intensity of a plurality of different patches.

[0139] In particular, a first patch PAI may be generated by a first linear array and a second patch PA2 may be generated by a second linear array. The first patch PAI and the second patch PA2 may each be formed from a set of sub-patches SP1, SP2, SP3, SP4, each sub-patch resulting from the output of a different LED arrangement (or set of synchronously controlled LED arrangements). Each sub-patch is therefore formed from the first part of light output by one or more LED arrangements.

[0140] As previously explained, the lighting device 100 may comprise a control unit configure to control at least the color and / or intensity of light output by each LED arrangement. In this way, the color and / or intensity of each sub-patch SP1, SP2, SP3, SP4 (and each patch PAI, PA2) may be controlled by the control unit.

[0141] The control unit may be manually controlled to facilitate manual control over the color of light emitted by each LED arrangement.

[0142] For instance, the control unit may be configured to communicate with a user input interface, e.g., via an application hosted by a mobile phone. The user input interface may be configured to provide a control signal indicating a desired operation of each LED arrangement.

[0143] The user input interface may, for instance, receive a direct control indication from the user specifying a color for each LED arrangement. As another example, the user input interface may be configured to process an image and / or description provided by the user to determine or select a color for each LED arrangement, and provide this information to the control unit.2024PF80453

[0144] 16

[0145] In some examples, the control unit may itself comprise a user interface. Thus, the lighting device 100 may comprise a user interface, e.g., on a top of the lighting device and / or on one side of the tubular housing. The user interface may, for instance, comprise one or more buttons, touch-sensitive displays or panels, switches, toggles or any other similar input elements suitable for generating control information for controlling the operation of the LED arrangements. More specifically, each input element may be configured to allow a user to send or define control signals to the control system, which sends corresponding signal(s) to the LED arrangements for controlling their operation.

[0146] Figure 8 illustrates an example of the lighting device 100 comprising a user interface to illustrate optional positions or locations for elements of the user interface. In particular, the lighting device may comprise a first user interface portion 810, located on the top of the lighting device and / or a second user interface portion 820, located on the side of the lighting device.

[0147] Other example locations will be readily apparent to the skilled person, e.g., at the base of the tubular housing, on the stand and so on.

[0148] As another example, the control unit may be adapted to communicate with a remote control to permit remote control of the lighting device. The remote control may, for instance, comprise one or more buttons, touch-sensitive displays or panels, switches, toggles or any other similar input elements suitable for generating control information for controlling the operation of the LED arrangements. A user may interact with the input element(s) of the remote control, which may in turn send signals (e.g., over an infrared channel, via a wireless network and / or via a direct communication channel such as Wi-Fi Direct) to the control unit. The control unit may react accordingly, to thereby control the operation of the LED arrangement responsive to the interaction with the remove control.

[0149] In some examples, the control unit comprises one or more sensors. Example sensors include presence sensors (e.g., PIR sensors), light sensors, time-of-flight sensors, cameras and so on. Each sensor may be integrated within the lighting device body. Each sensor captures sensor or environment information (e.g. presence of human beings, ambient light, adjacent object’s color(s) and so on) which may be carried by one or more sensor signals. The sensor signal(s) are passed or sent to the control system, which controls the operation of the LED arrangements accordingly. Thus, the control unit may be configured to receive the sensor signal(s) from the sensor(s), and control the operation of the LED arrangements responsive to the sensor / environment information carried by the sensor signals.2024PF80453

[0150] 17

[0151] For instance, the lighting device may comprise a lux sensor (i.e., a light intensity sensor) that works in conjunction with the linear arrays 421, 422. The control unit may be configured to control the brightness of any active LED arrangement responsive to the sensed light intensity, e.g., to maintain a consistent brightness of total light incident upon the second surface and / or to react to changes in ambient light level.

[0152] As another example, the lighting device may comprise a distance sensor, such as a time-of-fhght sensor, configured to face the second surface (a wall) 195 and monitor the relative distance to the wall (i.e., between the lighting device and the wall). The control unit may control one or more properties of the LED arrangements, such as brightness, responsive to the determined distance. For instance, the control unit may increase the brightness for increasing distances, e.g., to ensure a consistent and repeatable illumination of the wall.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] Any reference signs in the claims should not be construed as limiting the scope.

Claims

2024PF8045318CLAIMS:

1. A lighting device (100) for positioning on a planar surface (190), the lighting device comprising:a tubular housing (110) configured to extend, when the lighting device is positioned on the planar surface, in a first direction (Yl) substantially perpendicular to the planar surface, wherein the tubular housing comprises:a first light exit window (411) on a first side portion (111) of the tubular housing; anda second light exit window (412) on a second side portion (112) of the tubular housing; wherein the first side portion (111) is adapted to face towards a second surface (195), and the second side portion (112) is adapted to face away from the second surface (195) and towards an observer;wherein the second surface (195) is substantially perpendicular to the planar surface (190);linear arrays (421, 422) of LED arrangements (431, 432, 531, 532) positioned in the tubular housing, wherein each LED arrangement is configured to output light (L) having a controllable color and each linear array extends parallel to the first direction (Yl), wherein the linear arrays comprises:a first linear array (421), wherein each LED arrangement (431, 531) of the first linear array is configured to project the first part (LI) of light output by said LED arrangement in a direction parallel to a first projection direction; anda second linear array (422), wherein each LED arrangement (432, 532) of the second linear array is configured to project the first part (LX) of the output light in a direction parallel to a second projection direction, wherein the second projection direction makes a nonzero angle (a) with respect to the first projection direction;wherein each LED arrangement is configured to:project a first part (LI, LX) of the light output by said LED arrangement out of the first light exit window of the tubular housing towards the second surface (195); and2024PF8045319leak a second part (L2) of the light output by said LED arrangement out of the second light exit window of the tubular housing, wherein the second part is leakage light resulting from the projecting of the first part of the output light;wherein:for each linear array of LED arrangements, the tubular housing defines a respective first optical cavity (441A, 441B) and each LED arrangement of the linear array projects light out of the first light exit window through said first optical cavity;the LED tubular housing defines a second optical cavity (442) optically connected to each first optical cavity; andfor each LED arrangement of each linear array, the second part (L2) of the light output by the LED arrangement is light that leaks from the first optical cavity (441 A, 441B) of the respective first optical cavity of said linear array into the second optical cavity (442);wherein the first optical cavity (441A) for the first linear array (421) is not directly optically connected to the first optical cavity (44 IB) for the second linear array (422).

2. The lighting device of claim 1, wherein a smallest angle (a) between the first projection direction and the second projection direction is less than 180°.

3. The lighting device of any one of claims 1 or 2, wherein the first projection direction and the second projection direction are substantially perpendicular to the first direction.

4. The lighting device of claim 1, wherein the first optical cavity and the second optical cavity are optically connected together by a translucent or transparent portion (450) of a divider for securing the linear arrays of LED arrangements to the tubular housing.

5. The lighting device of any one of claims 1 to 4, wherein the second light exit window (412) comprises a diffuser for diffusing the second part of light received from each LED arrangement.

6. The lighting device of any one of claims 1 to 5, wherein, for each linear array, the LED arrangements are spaced apart by a distance (DI) of between 5 mm and 30 mm.2024PF80453207. The lighting device of any one of claims 1 to 6, wherein, for each LED arrangement, the first part (LI, LX) of the light output by the LED arrangement comprises no less than 60% of the light output by the LED arrangement.

8. The lighting device of any one of claims 1 to 7, wherein the tubular housing has a rounded cross-sectional shape along its length.

9. The lighting device of any one of claims 1 to 8, wherein the tubular housing is formed of transparent or translucent material.

10. The lighting device of any one of claims 1 to 9, wherein the second part (L2) of light output by each LED arrangement is light generated by said LED arrangement that is reflected and / or scattered by the first light exit window.

11. The lighting device of any one of claims 1 to 10, wherein the planar surface is a horizontal surface, such that the first direction extends vertically; further comprising a stand (120, 620) for positioning the light device on the planar surface.

12. The lighting device of any one of claims 1 to 11, further comprising a control unit (810, 820) and / or a sensor configured to control the color of light output by each LED arrangement.

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