Lighting device with mechanical dimming system

Abstract

A lighting device (100) is disclosed, comprising a socket (110) configured to hold a light source (115) for generating light, a housing (120) arranged to at least partly enclose the light source, and a mechanical dimming system (130) supported by the housing and operable to control an amount of light emitted from the lighting device. The mechanical dimming system comprises a first adjustable aperture (A1) for controlling the amount of light emitted from the lighting device in a first direction, and a second adjustable aperture (A2) for controlling the amount of light emitted from the lighting device in a second direction.

Description

[0001]LIGHTING DEVICE WITH MECHANICAL DIMMING SYSTEM Technical field The present disclosure relates to lighting devices, and more particularly to lighting devices having mechanical dimming systems. Background Dimmable lighting devices offer the possibility to adjust the lighting to create the desired ambience for any situation. The dimming is often provided by electronic dimmers that control the amount of power delivered to the light source. A common type of dimming method is the ‘phase-cut’ dimming which reduces the power by ‘cutting’ a portion of each waveform of the AC power supply. While these dimmers are popular and widely used, they come with drawbacks such as complex circuitry which can drive production costs, sensitivity to power surges, and noise caused by the interaction between the circuitry and the electrical characteristics of the light source. There is therefore a need for improved technologies for controlling the amount of light emitted from lighting devices. It is an object of the present disclosure to provide a technology that addresses at least some of the above concerns. According to an aspect, there is provided a lighting device comprising a socket configured to hold a light source for generating light, a housing arranged to at least partly enclose the light source, and a mechanical dimming system supported by the housing and operable to control an amount of light emitted from the lighting device. The mechanical dimming system comprises a first adjustable aperture for controlling the amount of light emitted from the lighting device in a first direction, and a second adjustable aperture for controlling the amount of light emitted from the lighting device in a second direction. The mechanical dimming system is composed predominantly of mechanical components, eliminating the need for electronic parts. This design may inherently Internal enhance robustness and durability compared to electronic systems, which may be more vulnerable to failures caused by voltage spikes, component degradation, or electromagnetic interference. Consequently, the mechanical dimming system may be associated with a longer operational lifespan and may be simpler to maintain and repair. Additionally, mechanical dimmers do not produce electromagnetic interference or noise, issues commonly associated with electronic dimmers that use pulse-width modulation for controlling light output. Further, electronic systems can induce thermal cycling and stress on the filament of the light source, potentially shortening its lifespan. This issue can be effectively addressed by the mechanical dimming system, which avoids altering the electrical current. Moreover, a primarily mechanical dimming system comprises fewer hazardous materials than its electric counterparts and contributes less to electronic waste. Its straightforward design also facilitates easier disassembly and separation of recyclable materials, enhancing environmental sustainability. The dimming system is designed to control the amount of light that passes through an opening, or adjustable aperture. By adjusting the size of the opening, a user can precisely control the intensity of the light emitted from the lighting device while maintaining a relatively uniform and concentric light distribution. The adjustable apertures may, for example, be arranged along an optical axis of the lighting device to promote a uniform and consistent spread of the light as it dims. The first and second adjustable apertures may face in opposite directions to better distribute the light throughout a space and provide a more balanced illumination. When in use, the lighting device may be oriented with the opposing directions facing vertically, horizontally, or any other direction in between. A vertical orientation may allow the ceiling and the floor or a tabletop to be illuminated at the same time. The adjustable apertures may be formed by one or more blades or leaves that slides across the opening to progressively block the light. This arrangement may be referred to as a ‘dimmer’ or ‘shutter’ and may comprise one or more blades for dimming the light. In some examples, a single blade shutter may be employed, comprising a single blade for blocking the light. Other examples include multiple blades that overlap or fit together to define an optical passageway, or central opening, through which the Internal light can be emitted from the lighting device. These blades can be adjusted individually or collectively to achieve finer control of the light intensity and pattern. In specific examples, the dimmer comprises a series of blades that can expand or contract in a circular pattern to adjust the cross-sectional area of the optical passageway through which light passes. This allows for an improved and more precise control of light intensity and is commonly referred to as an iris diaphragm. The plurality of blades can be opaque to block light not passing directly through the aperture, thus enhancing the contrast between the fully open and fully dimmed states of the aperture. In examples where the aperture can be fully closed, opaque blades may allow for a complete blocking of light. In other examples, the blades may be at least partly light transmitting, such as translucent. Translucent blades may allow for a controlled diffusion of light even when partially closed, thereby softening the light transitions between the fully open and fully dimmed states of the aperture. This may enable a gradual dimming effect and maintain a natural ambience by softly filtering light through the aperture. Each blade may have a pivot, where it is mounted to a fixed outer ring or frame. The actuating mechanism, such as a rotating ring or lever, may control the movement of the blades around the pivot. Rotating the control in one direction may cause the blades to retract towards the perimeter of the adjustable aperture, thereby increasing the size of the central opening, while rotating the control in opposite direction causes the blades to overlap more towards the centre, reducing the size of the central opening. The housing of the lighting device may comprise a first part and a second part which are movable in relation to each other. The outer ring or frame, to which the blades are rotatably mounted, may be attached to the first part of the housing whereas the actuating mechanism may be attached to the second part of the housing. By moving the first and second parts relative to each other, the blades may be caused to widen or decrease the aperture. In some examples, the first part and the second part of the housing are rotatable in relation to each other to actuate the blades. The lighting device may comprise one or more light diffusing means for softening the light and reducing glare. The light diffusing means may also be referred to as a diffuser, or diffuser plate, depending on its design. In some examples, the housing comprises a first light diffusing means facing the first direction and a second Internal light diffusing means facing the second direction. This arrangement allows of the light emitted in the first and the second to be diffused. Beneficially, the first and second adjustable apertures may be arranged between the light source and the respective diffusing means to ‘mask’ the apertures, i.e., to make them less visual to the user. The housing may comprise a first part (also referred to as a 'body'), the first diffuser, and the second diffuser. The diffuser may be attached to a respective opening of the first part, such that the housing forms a substantially closed volume. In some examples, the first part has a cylindrical shape with a diffuser at its respective end portion. In different words, one or more of the diffusers may form a lid at least partly closing the cylindrical first part. The first part may be formed of an opaque material to prevent light from passing through. As a result, the substantially all light emitted from the lighting device is emitted through the first and / or second adjustable apertures. This allows for the contrast between fully open and fully dimmed state to be increased. In other examples, the first part may be formed of an at least partly light transmitting material, such as a translucent material. This allows for light to escape the lighting device through the first part also when the dimming system is in its fully dimmed state. The term ‘lighting device’ typically encompasses a broad array of types and styles suitable for various applications. Examples of such devices include, but are not limited to, table lamps, floor lamps, wall-mounted lamps, pendant lamps, and desk lamps. In a specific example, the lighting device comprises a base or foot portion configured to support the lighting device in a stable, and upright position on surfaces such as a table, a windowsill, or a desk. The foot portion may either be integrated into or attached to the main housing of the lighting device. Additionally, the foot portion can be engineered to actuate the dimming system by its rotation relative to another part of the housing, enhancing the functionality and user interaction with the device. The light source may be of various types, including traditional options such as halogen spots or incandescent lamps, as well as semiconductor light sources like LEDs and OLEDs. It should be appreciated that the lighting device can incorporate multiple light sources, such as a pixilated LED array, and / or light sources of different colours to enhance functionality and aesthetic appeal. Internal A light diffusing means, or simply ‘diffuser’, is understood as a component capable of scattering light, thereby spreading or softening the light emitted from the lighting device. The design and configuration of the diffuser may vary depending on the lamp’s overall design. For instance, the diffuser might be formed as a planar disc or ring that can be attached to an opening of the housing. The diffuser may typically be formed from materials such as plastic or glass and may be frosted or otherwise patterned to effectively control light diffusion. Further examples include micro prismatic diffusers, which utilise a surface pattern of small prisms to evenly distribute light. It is also noteworthy that multiple diffusers can be stacked along a common axis, requiring light to traverse through the entire stack before escaping the lighting device. Further features and examples of the invention will become apparent from the following description of embodiments, given by way of example only, which is made with reference to the accompanying drawings. Various aspects and examples of the present disclosure will be readily understood from the embodiments discussed in the following detailed description and the accompanying drawings, in which: Figure 1 is a cross section of a lighting device according to an example; Figure 2 is a cross section of a lighting device according to another example; Figures 3a and b are exploded views of adjustable apertures; and Figure 4 is a perspective view of a lighting device according to an example. Detailed Figure 1 is a cross-sectional view of a lighting device 100 according to an embodiment. The lighting device 100 comprises a socket 110 for securing a light source 115, and a housing 120 arranged to at least partly enclose the light source 115. A mechanical dimming system 130, supported by the housing 120, is arranged to control the amount of light emitted from the lighting device 100. This is achieved through a first adjustable aperture A1, which regulates light emitted in a first direction, and a second adjustable aperture A2, which controls light emitted in a second direction. Internal Various types of light sources 115 are possible. The present example comprises a light emitting diode (LED), which advantageously generates relatively little heat compared to, e.g., incandescent bulbs. The LED 115 may be releasably mounted in the socket 110 supplying the LED 115 with the electric power required for its operation. It should be noted that the socket 110 and the light source 115 are schematically illustrated in figure 1, and that the socket 110 in various implementations of the lighting device 100 may be supported by a base or by the housing 120. The housing 120 is arranged to at least partly enclose the light source 115. More specifically, the light source 115 may be arranged within the housing 120, allowing light generated by the light source 115 to exit the lighting device 100 through the housing 120. This light may pass through the housing material itself, which hence may be partially light-transmitting, or escape via openings in the housing 120. Various materials can be used to form the housing 120. For instance, the housing 120 may be formed from a light-transmitting material, such as frosted plastic or glass, which scatters the light as it passes through. Alternatively, in other examples, the housing 120 may be formed of an opaque material, such as opaque plastic or metal, directing the majority of the light to escape through designated openings in the housing 120. The depicted housing 120 of the lighting device 100 comprises two openings: a first opening facing in a first direction and a second opening facing in a second direction, with the first designated as the top opening and the second as the bottom opening in this example. However, various shapes and orientations of the housing 120 are conceivable, depending on the lighting device’s 100 design and configuration. The housing 120 could be cylindrical with a circular, oval, or polygonal cross-section. The absolute orientation of the openings may vary depending on the lighting device’s 100 usage and installation. Additionally, it is important to note that the first and second directions are not limited to being directly opposite each other at 180°; they could also, for example, be orthogonal, or even face the same direction, depending on the specific usage and illumination requirements. The dimming system 130 may be arranged at the openings of the housing 120 to control the amount of light exiting the housing 120. Specifically, in this embodiment, a first adjustable aperture A1 is arranged at the first opening of the housing 120, and a second adjustable aperture A2 is arranged at the second opening of the housing 120. Internal Each aperture A1, A2 may be formed by a respective dimmer 131, 132, which comprises one or more light blocking elements such as movable blades, shutters, or leaves. As depicted in figures 3a and b, each dimmer 131, 132 comprises a plurality of partially overlapping blades forming an iris diaphragm. These dimmers 131, 132 may be mounted within the housing 120, aligned to cover the respective openings of the housing 120 completely to ensure that light can only escape through the adjustable apertures A1, A2. Additionally, the dimmers 131, 132 may, for example, be formed as plates that fit snugly within the interior of the housing 120, effectively sealing any gaps between the dimmers 131, 132 and the housing walls to prevent uncontrolled light leakage. The size of the apertures A1, A2 may be adjusted (as indicated by arrows in figure 1) to control the intensity of light emitted by the lighting device 100. These apertures A1, A2 may be adjusted gradually, ranging from a fully open state, where the apertures A1, A2 achieve their maximum cross-sectional area, to a fully dimmed state where the apertures A1, A2 have their minimum cross-sectional area. In the fully dimmed state, the apertures A1, A2 may be completely closed (corresponding to a zero cross-sectional area) or remain slightly open to allow at least some light to pass through. The light blocking elements utilised can be opaque to fully block light, or they may be partly light-transmitting or translucent to soften the transition between the fully open and fully dimmed states. In the specific example shown in figure 1, the lighting device 100 further comprises light diffusing means 141, 143, which serve to soften the light emitted from the lighting device 100. The light diffusing means 141, 143 may be arranged to obscure the dimmers 131, 132 to make them less distinctly visible and enhance the dispersion of light. Referred to simply as ‘diffusers’, these components may be formed from a variety of materials including glass, plastic, and fabric, each chosen for its specific diffusion properties, durability, or aesthetic appeal. In the specific example shown in figure 1, the diffusers 141, 143 are formed of a plastic material that scatters the light effectively. The diffusers 141, 143 are shaped as plates that can be attached directly over the respective openings of the housing 120 to cover them completely. In further examples, the diffusers 141, 143 may be integrated into the housing 120 itself, forming an integral part of its structure. Internal Figure 2 is a cross-sectional view of a lighting device 100 according to an embodiment, which may be configured similarly to the lighting device 100 depicted in figure 1. However, in this version the housing 120 is formed of two main parts - a first part 121 forming a body of the housing 120, enclosing the socket 110 and the light source 115, and a second part 122 forming a foot portion 122, or base of the housing 120. The base 122 may support the socket 110 and stabilise the lighting device 100 when it stands upright. The body 121 may be designed with the first and second openings at its respective ends, facilitating the escape of light generated by the light source 115. The body 121 may, for example, be cylindrical, with the top and bottom openings arranged at the respective ends of the cylinder. The cross section of the cylinder may be circular, oval, or polygonal. Other types of cross sectional-shapes are however possible. The base 122 is positioned at the bottom opening of the body 121 and is designed with a diameter smaller than the body 121. This configuration allows light to escape through a ring-shaped gap between the body 121 and the base 122. Consequently, the second dimmer 132 may be adapted to fit this arrangement. In this setup, the adjustable aperture A2 may form a continuous peripheral ring between the upper part of the base 122 and edge of the bottom opening in the body 121. This design allows the base 122 to be positioned centrally at the opening of the body portion 122 and the aperture A2 to encircle it. The second dimmer 132, which defines the adjustable aperture A2, may comprise a plurality of adjustable blades which can vary the diameter of this annular aperture A2. The first and second dimmers 131, 132 are operable by manipulating the base 122 relative to the body 121. This movement may include a relative rotation around a central axis C, which in the present example aligns with the directions in which light is exiting both dimmers 131, 132. To facilitate synchronous actuation of the dimmers 131, 132, an actuating mechanism 134 may couple the dimmers 131, 132 to each other. This actuating mechanism 134 may, for example, comprise a set of rods 134 that extend between the first dimmer 131 and the second dimmer 132, transferring motion and allowing simultaneous adjustment of the first and second apertures A1, A2 in response to the movement of the base 122 relative to the body 121. Rotating the base 122 in one direction may cause the first and second dimmers 131, 132 to open fully, increasing the Internal light intensity by maximising the width or open area of the apertures A1, A2. Conversely, rotating the base 122 in the opposite direction may drive the first and second dimmers 131, 132 to their fully dimmed state, thereby narrowing the apertures A1, A2 and reducing light intensity. As shown in figure 2, light may exit the housing 120 through the top opening and the annular opening at the bottom of the body portion 121. The top opening may be covered by a first diffuser 141, similar to the one discussed above in connection with figure 1. Meanwhile, the annular opening at the bottom, which encircles the centrally located base 122, may be covered by a second diffuser 143. The second diffuser 143 may be annular or ring-shaped and may include a central opening designed to accommodate the base 122. A non-limiting example of a mechanical dimming system 130 will now be described with reference to figures 3a and b. Figure 3a shows an exploded view of a first dimmer 131, which is configured to be covered by a first diffuser 141, while figure 3b shows an exploded view of a second dimmer 132 alongside a second diffuser 143. These components may be configured similarly to those illustrated in figures 1 and 2. The depicted dimmers 131, 132 employ a series of partially overlapping blades 210, 220, 310, 320 to adjust the cross-sectional area of an optical passageway, i.e., the adjustable apertures A1, A2 shown in figures 1 and 2. The manipulation of the apertures A1, A2 is facilitated by a control ring or similar actuating mechanism that ensures synchronous movement of the blades, expanding or contracting the aperture. The first dimmer 131 shown in figure 3a comprises two sets of blades 210, 220 held in position between two blade holder rings 211, 221. One ring is situated above and the other below the blades 210, 220, securely clamping them in place. The first set of blades 210 are pivotally attached to the upper blade holder ring 211, while the second set of blades 220 are pivotally attached to the lower blade holder ring 221. An actuator ring 230, positioned between these two sets, features guide slits 232 which engage with protruding guide pins 212, 222 on the blades 210, 220. Rotating the actuator ring 230 causes the blades 210, 220 to either converge towards the centre opening or diverge away from it, effectively closing or opening the aperture A1. The blade holder rings 211, 221 may be secured to the body 121 of the housing 120 by two attachment rings 142, 231. These attachment rings 142, 231 may be Internal configured to clamp the blade holder rings 211, 221 and secure the entire assembly firmly to the housing body 121. The actuator ring 230 may be provided with tabs 233 – small, outwardly projecting parts – that can be used to rotate the actuator ring 230. In the present example, the tabs 233 comprises holes by means of which the actuator ring 230 can be attached to the rods 134 shown in figure 2. By rotating the actuator ring 230 relative to the housing body 121 and thus the blade holder rings 211, 221, the blades 210, 220 may be caused to converge towards, or diverge away from, the opening. The first diffuser 141 may be attached to the housing body 121 by one of the attachment rings 142, such that the light that passes through the first diffuser 141 after exiting the first dimmer 131. The second dimmer 132 may be similarly configured with a dual set of blades 310, 320, each clamped between an upper blade holder ring 311 and a lower blade holder ring 321, as shown in figure 3b. The first set of blades 310 are pivotally attached to the upper blade holder ring 311, and the second set of blades 320 to the lower blade holder ring 321. Furthermore, an actuator ring 332 with guide slits 332 may be arranged between these two sets, with the guide slits 332 engaging with protruding pins 312, 322 of the blades 330 to allow the blades 330 to reduce or increase the opening through the dimmer 132 upon rotation of the actuator ring 330. However, it should be noted that unlike the first dimmer 131, the blades 310, 320 of this second dimmer 132 do not define a central opening. Instead, they define an annular opening that encircles the centre of the dimmer 132. This annular opening may be narrowed by moving the blades outward towards the periphery of the housing opening in which the dimmer 132 is arranged and increased by moving the blades inward towards the centre of the housing opening. In this way, an adjustable aperture may be formed, which is not obscured by the base 122. The actuator ring 330 may be attached to the housing body 121, while the blade holder rings 311, 321 may be attached to the rods 134, which in turn are connected to the base 122. Consequently, the second dimmer 132 may be actuated by rotating the base 122, and hence the blade holder rings 311, 321, relative to the housing body 121. It should be noted that this configuration is inverted compared to the configuration of the first dimmer 131, in which it is the blade holder rings 211, 221 that are attached to the housing body 121. Internal The blade holder rings 311, 321 of the second dimmer 131 may be connected to the actuator ring 230 of the first dimmer 131 by means of the rods 134 shown in figure 2, causing both dimmers 131, 132 to be actuated at the same time by rotating the housing body 121 and the base 122 relative to each other. The second diffuser 143 may be attached to the housing body 121 and may comprise guide pins 144 configured to engage with corresponding tabs 333 of the actuator ring 330 to cause the actuator ring 330 to rotate together with the housing body 121. Figure 4 is a perspective view of a lighting device 100 according to an embodiment, which may be configured similarly to the embodiments illustrated in figures 1 and 2. Further, it may comprise a mechanical dimming system similar to the one discussed with reference to figures 3a and b. The lighting device 100 depicted in figure 4 is a table lamp configured to be supported by the base 122, or foot, of the housing 120. The base 122 provides a support for the body 121 as well as the light source (not shown), as well as the electronic circuitry and power supply necessary for the operation of the lamp 100. In the present example, the base 122 comprises a push button for turning on and off the light source. Further, an electric cord is indicated 124, supplying the lamp 100 with electric power. The housing 120 comprises a cylindrical body 121 which a circular cross section. The body 121 is formed from, but not limited to, sheet metal, which effectively blocks light transmission. The body 121 may also be made of other materials, such as plastic materials including acrylonitrile butadiene styrene (ABS) and polypropylene (PP). The top opening of the cylindrical body 121 is covered with a top diffuser 141, which may be formed of a polymethyl methacrylate (PMMA), PP, or polycarbonate plate scattering the light passing through. The diffuser 141 may, for example, be injection moulded. As shown in the present figure, the base 122 may have a cylindrical shape similar to the body 121, allowing the base 122 to support the lamp 100 in an upright position when standing on a horizontal surface such as a table. The diameter of the base 122 is smaller than the diameter of the body 121 to allow light to pass through the annular opening formed between the body 121 and the base 122. This annular opening may be covered with a bottom diffuser 143 (not visible in figure 4), which may be Internal formed of the same type of material as the top diffuser 141. Thus, the bottom diffuser 143 may be formed of a PMMA, PP, or polycarbonate annular disc attached to the bottom opening of the body 121. During operation, the lamp 100 may be dimmed by rotating the body 121 in relation to the base 122. This rotation may cause the blade holder rings 211, 221 of the first dimmer 131 to rotate with the body 121 while the actuator ring 230, which is attached to the base 122 via the rods 134, is stationary (see figures 3a and b). This relative rotation between the blade holder rings 211, 221 and the actuator ring 230 causes the blades 210, 220 to move to close or open the first aperture A1. Similarly, the rotation of the body 121 causes the actuator ring 330 of the second dimmer 132 to rotate with the body 121 while the blade holder rings 311, 321, which are attached to the base 122, are stationary. This relative rotation between the actuator ring 330 and the blade holder rings 311, 321 causes the blades 310, 320 to open or close the second aperture A2. Internal

Claims

CLAIMS 1. A lighting device (100), comprising: a socket (110) configured to hold a light source (115) for generating light; a housing (120) configured to at least partly enclose the light source; and a mechanical dimming system (130) supported by the housing and operable to control an amount of light emitted from the lighting device; the mechanical dimming system comprising: a first adjustable aperture (A1) for controlling the amount of light emitted from the lighting device in a first direction, and a second adjustable aperture (A2) for controlling the amount of light emitted from the lighting device in a second direction.

2. The lighting device according to claim 1, wherein each of the first and second adjustable apertures comprises a plurality of partially overlapping blades defining an optical passageway.

3. The lighting device according to claim 2, wherein the plurality of partially overlapping blades are operable to decrease a cross-sectional area of the optical passageway and to increase the cross-sectional area of the optical passageway.

4. The lighting device according to claim 2 or 3, wherein each of the first and second adjustable apertures is an iris diaphragm.

5. The lighting device according to any of claims 2-4, wherein the plurality of blades are opaque.

6. The lighting device according to any of claims 2-4, wherein the plurality of blades are translucent. Internal7. The lighting device according to any of claims 2-6, wherein the plurality of blades are rotatably attached to a first part (121) of the housing and configured to be actuated by an actuating mechanism (134) coupled to a second part (122) of the housing.

8. The lighting device according to claim 7, wherein the first part and the second part of the housing are rotatable in relation to each other to actuate the plurality of blades.

9. The lighting device according to claim 7 or 8, wherein the first part of the housing is opaque.

10. The lighting device according to claim 7 or 8, wherein the first part of the housing is translucent.

11. The lighting device according to any of claims 7-10, wherein the second part of the housing forms a foot portion configured to support the first part of the housing when the lighting device is standing in an upright position.

12. The lighting device according to any of claims 7-11, wherein the first part of the housing comprises: a first light diffusing means (141) facing the first direction; and a second light diffusing means (143) facing the second direction.

13. The lighting device according to claim 12, wherein the first light diffusing means is configured to face upwards, and the second light diffusing means is configured to face downwards when the lighting device is in the upright position.

14. The lighting device according to claim 12 or 13, wherein the housing is cylindrical and the first and second light diffusing means are arranged at a respective end portion of the housing. Internal

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