FIELD OF THE INVENTION

The present invention relates to a lighting device, in particular to a lighting device comprising Solid State Lighting (SSL) elements.

The present invention also relates to a luminaire comprising the lighting device.

The present invention also relates to a method of configuring the lighting device, a computer program product for implementing the method and a computing device including the computer program product.

The present invention also relates to a lighting system comprising the lighting device.

BACKGROUND OF THE INVENTION

With a continuously growing population, it is becoming increasingly difficult to meet the world's energy needs and, simultaneously, to control carbon emissions to kerb greenhouse gas emissions which are considered responsible for global warming phenomena. These concerns have triggered a drive towards a more efficient use of electricity in an attempt to reduce energy consumption.

One such area of concern is lighting applications, either in domestic or commercial settings. There is a clear trend towards the replacement of traditional, relatively energy- inefficient, light bulbs such as incandescent or fluorescent light bulbs with more energy efficient replacements. Indeed, in many jurisdictions the production and retailing of incandescent light bulbs has been outlawed, thus forcing consumers to buy energy-efficient alternatives, for example when replacing incandescent light bulbs.

A particularly promising alternative is provided by solid state lighting (SSL) elements, which can produce a unit luminous output at a fraction of the energy cost of incandescent or fluorescent light bulbs. An example of such a SSL element is a light emitting diode (LED).

It is known to provide SSL element-based lighting devices having a similar overall shape to incandescent light bulbs, for example, bulbous SSL element-based lighting devices. However, it is a particular challenge to provide an appearance that is comparable with traditional lighting devices wherein appearance is an important factor for market penetration as customers may like or be accustomed to the appearance of incandescent light bulbs. This is particularly problematic where the SSL element-based lighting device is configurable, as such different configurations may require different optics that prevent the SSL element-based lighting device from having an appearance similar to that of traditional lighting devices such as incandescent light bulbs.

SUMMARY OF THE INVENTION

The present invention inter alia seeks to provide a configurable SSL element- based lighting device that can have an appearance comparable with traditional lighting devices, such as traditional incandescent light bulbs, GLS bulbs, or SSL element based lighting devices resembling such bulbs.

The present invention further seeks to provide a luminaire including such a lighting device.

The present invention yet further seeks to provide a method of configuring such a lighting device.

The present invention yet further seeks to provide a computer program product implementing such a method.

The present invention yet further seeks to provide a computing device including such a computer program product.

The present invention yet further seeks to provide a lighting system including the lighting device and optionally the computer program product and/or the computing device.

According to an aspect, there is provided a lighting device comprising a housing including a bulbous light exit window comprising a first region adjoining a second region, a first set of solid state lighting elements in said housing for providing light to the first region; and a second set of solid state lighting elements in said housing for providing light to the second region, wherein the second region comprises a frosted glass or plastic having a first translucence and wherein the first region comprises a material having a translucence adjustable between at least a first state having the first translucence and a second state having a second translucence.

By controlling the first and second sets of solid state lighting elements independently and controlling the state of the material a multiplicity of lighting effects may be produced. This lighting device can therefore provide a range of different lighting effects using only a single adjustable material and a minimum of two sets of solid state lighting elements. A narrow spot beam may be obtained when the first set of solid state lighting elements are powered, and an omnidirectional light distribution may be obtained by powering the second set of solid state lighting elements. Additionally this lighting device can also be aesthetically pleasing because the bulbous light exit window may be given a uniform appearance by adjusting the material into a state of first translucence, thus matching the translucence of the second region. This may be particularly advantageous in persuading consumers who are accustomed to the overall appearance of an incandescent bulb to choose such a lighting device. When the lamp is in the OFF state, the translucence of the first region may be in the diffuse state and therefore may match the translucence of the region of the light exit window thus allowing the lighting device to provide the same visual attributes as an incandescent bulb in the OFF state. Preferably, the diffuse translucence of the first region may mean that the first set of solid state lighting elements cannot be seen by an observer when the lighting device is in the OFF state.

The lighting device may further comprise a controller for adjusting the material to different degrees of translucence and for selectively enabling, and optionally dimming, the first set and/or the second set of solid state lighting elements in different operation modes of the lighting device. This has the advantage that the lighting device is operable in a self-contained fashion, i.e. without the need for a separate controller.

The controller may be configured to switch the lighting device between:

a first mode of operation in which the first and second sets of solid state lighting elements are on and the material is adjusted to the first state; and at least one of:

a second mode of operation in which the first set of solid state lighting elements is on, the second set of solid state lighting elements is off and the material is adjusted to the second state; and

a third mode of operation in which the first set of solid state lighting elements is on, the second set of solid state lighting elements is off and the material is adjusted to the first state.

The controller may be further configured to receive configuration instructions and control the first and second set of solid state lighting elements and the material in accordance with said configuration instructions such that the lighting device can be controlled remotely, e.g. using wired or wireless communications, in which case the controller may be coupled to an antenna for receiving the wireless communication. The lighting device may comprise at least one off state in which the material is in the first state in order to provide the bulbous light exit window with a uniform appearance in the off state, e.g. for the aforementioned aesthetic reasons.

The second state may be a transparent state, in which case the first state for instance may be a scattering or dispersive state. This facilitates a mode of operation of the lighting device in which all SSL elements may be activated whilst the material is in the first state, thereby providing a diffusive lighting device mimicking the appearance and/or luminous distribution of an incandescent light bulb, whilst further facilitating a mode of operation in which the first set of SSL elements may be selectively engaged to produce a spot light effect through the transparent material. This means that a single lighting device can offer both task lighting in the spot configuration and ambient lighting in the flood

configuration.

The material advantageously may be a polymer dispersed liquid crystal material. Such materials may be relatively easily adjusted between a continuum of states having different translucence characteristics.

The material may define a single pixel across the entire first region;

alternatively, the material may be pixelated. Where the material is pixelated the individual pixels may be addressed as in a display, in this way dynamic projections can be provided in the modes discussed above.

The lighting device may further comprise an electrode arrangement for adjusting the material between the first state and the second state.

The second region may be formed of a frosted glass or plastic, e.g. a coated or etched glass or plastic material, a plastic material filled with scattering particles, a silicone polymer, and so on. Such materials may be advantageous in that their degree of translucency may be adapted relatively simply, e.g. to match the translucency of the second region to that of the material in the first state for aesthetic reasons as previously explained.

The first and/or second sets of solid state lighting elements may be arranged to produce white light. The white light may be of any correlated color temperature (CCT).

The first and/or second sets of solid state lighting elements may be arranged to be tuneable to provide a selected colored or white light.

The first set of solid state lighting elements may be arranged to produce light of a first spectral composition and the second set of solid state lighting elements be arranged to produce light of a second spectral composition that is different to the first spectral composition. This for instance enables the lighting device to provide a multiplicity of colored lighting effects. Such lighting effects may be desired in certain applications and may be advantageously produced on user instruction.

The second region of the light exit window may surround the first region of the light exit window. Such a configuration may be used to provide a more focused light from the first region and a less focused light form the first and the second region together.

The second region of the light exit window may be centered around the optical axis of the lighting device.

The second set of solid state lighting elements may surround the first set of solid state lighting elements.

The lighting device may further comprise an opaque wall structure for confining the luminous output of the first set of solid state lighting elements to the first region in order to improve the focus of said luminous output, which may be advantageous when producing a spot light in one of the operating modes of the lighting device.

The opaque wall structure may be specular or diffusely reflective to reflect the luminous output of the first set of solid state lighting elements towards the first region and/or the luminous output of the second set of solid state lighting elements towards the second region to enhance the luminous efficiency which is achieved by the lighting device and/or to provide desired lighting effects or a desired aesthetic appearance of the lighting device.

According to a further aspect, there is provided a luminaire comprising the lighting device described above. Such a luminaire benefits from a configurable lighting device having an appearance that may mimic that of traditional lighting devices.

According to a yet further aspect, there is provided a method of configuring a lighting device according to one or more of the above embodiments, wherein the lighting device is adapted to receive configuration instructions, the method comprising receiving user inputs specifying configuration instructions for configuring the first set of solid state lighting elements, the second set of solid state lighting elements and the material of the lighting device; and transmitting said configuration instructions to the lighting device. Such a method facilitates a user to (remotely) configure the lighting device, which may further aid user satisfaction.

According to a yet further aspect, there is provided a computer program product comprising computer-readable storage means comprising computer program code for, when executed on one or more processors of a computing device, implementing the above method. This facilitates the execution of the method on generic computing devices, thereby improving flexibility. According to a yet further aspect, there is provided a computing device including at least one processor and the computer program product wherein the at least one processor is adapted to execute the code of said product. The computing device may be selected from the group consisting of a mobile phone, a phablet, a tablet, a desktop computer, a laptop computer, a personal organizer, a music player, such that the lighting device may be controlled by a generic computing device. Alternatively, the computing device may be a dedicated lighting controller, e.g. a dedicated remote controller of a lighting device or lighting system.

According to a yet further aspect, there is provided a lighting system comprising the lighting device according to one or more of the above embodiments and, optionally, the aforementioned computer program product or the aforementioned computing device. Such a lighting system benefits from the inclusion of a configurable lighting device having an appearance that can mimic the appearance of traditional lighting devices. BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are described in more detail and by way of non- limiting examples with reference to the accompanying drawings, wherein

Fig. 1 depicts a partially cut away view of a lighting device according to an embodiment of the present invention;

Fig. 2 schematically depicts the lighting device of Fig. 1;

Fig. 3 depicts a perspective view from above of the lighting device of Fig. 1; Fig. 4 depicts a perspective view of an embodiment of a luminaire comprising the lighting device of Fig. 1;

Fig. 5 depicts a flow chart of a method according to an embodiment of the present invention;

Fig. 6 depicts a computer program product according to an embodiment of the present invention; and

Fig. 7 depicts a computing device according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

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. Embodiments of the present invention are concerned with SSL element based lighting devices. An area identified for improvement in SSL element based lighting devices is the provision of lighting devices which can provide a multiplicity of lighting effects, for example spot lighting and/or ambient lighting, whilst at the same time having a pleasing aesthetic, for example having an appearance comparable to incandescent light bulbs.

In the following, where it is stated that a region or material of the lighting device has a first or a second translucence this means that the region or material has a particular degree of translucence. For instance, the region or material may have a high degree of transparency as a first translucence and a low degree of transparency, e.g. be diffusive or scattering, as a second translucence or vice versa; the first translucence may be greater than the second translucence, in other words, the second translucence may be more transparent than the first translucence. In other embodiments the second translucence may be greater than the first translucence, in other words, the first translucence may be more transparent than the second translucence.

In the present application, where reference is made to a material adjustable between a first translucence and a different second translucence, it should be understood that this includes materials for which the translucence may be gradually adjusted, i.e. a material comprising an infinite number of translucent states that may be invoked by employing an appropriate voltage across the material.

Referring firstly to Fig. 1 and Fig. 2 of the accompanying drawings, an embodiment of a lighting device 100 can be seen to comprise a housing 102 including a bulbous light exit window 104 comprising a first region 106 adjoining a second region 108. The second region 108 has a first translucence. The first region 106 comprises a material having a translucence adjustable between at least a first state having the first translucence and a second state having a second translucence, such that the material can be adjusted between a state in which its translucence is different to that of the second region 108 and another state in which its translucence is substantially the same to that of the second region 108. To this end, the lighting device 100 may include an electrode arrangement 109 as schematically shown in FIG. 2 that is arranged such that the arrangement can adjust the material between these different translucent states by applying an appropriate voltage across the material. The electrodes of the electrode arrangement 109 may be arranged in any suitable arrangement. The electrodes of the electrode arrangement 109 preferably are made of a transparent electrically conductive material, e.g. an electrically conductive oxide material such as Indium Tin Oxide (ITO), Fluorine-doped Tin Oxide (FTO), Indium Zinc Oxide (IZO), carbon nanotube-based materials, graphene-based materials or any other suitable transparent electrically conductive material.

The material of the first region 106 may be any suitable material that can be adjusted between states having different translucencies. In an embodiment, the material is a polymer dispersed liquid crystal (PDLC) material. Other acronyms are also used for such liquid crystal systems. Apart from PDLC (polymer dispersed liquid crystal), the terms PNLC (Polymer Network Liquid Crystal), LCPC (Liquid Crystal Polymer Composite), NCAP (Nematic Curvilinear Aligned Phase) and PSCT (Polymer Stabilized Cholesteric Texture) are used. Such materials comprise liquid crystals which are dissolved or dispersed in a polymer material. A PDLC material is essentially a matrix material in which droplets of liquid crystal are dispersed. Dispersion of the liquid crystal in the polymer can be obtained through methods of emulsion or phase separation. The emulsion may be polyvinyl alcohol (PVA) based, latex based or water based. Phase separation methods include polymerization induced phase separation, thermally induced phase separation and solvent induced phase separation.

For polymerization of the matrix material derivatives of the acrylate, methacrylate or vinyl families may be used. Alternatively thiolene and polyurethane or ring- opening polymerization reactions - such as epoxy chemistry can be used. The liquid crystal itself can be non-chiral and chiral liquid crystals. Dichroic dies can be incorporated into some types of PDLC films which enable the device to change from scattering into an absorbing state instead of a transparent state.

The optical properties of such a material may be controlled by applying a voltage across the PDLC material. Without the application of a voltage, the liquid crystals are randomly arranged, resulting in scattering of light as it passes through the material, yielding a diffuse state. This results in the material having a translucent, scattering, effect - consequently the material may have an opaque appearance, e.g. appear 'milky'. PDLC materials can be contrasted with twisted nematic displays which use variable absorbance; PDLCs can modulate light through a controllable scattering effect without the need for polarizers. The principal advantage of this is that PDLC materials have higher optical output.

When a voltage is applied to the material, the resulting electric field across the material causes the liquid crystals to align, thereby allowing light to pass through the material with very little scattering and resulting in a transparent state. Alternatively, in some embodiments the liquid crystals may be pre-aligned, such that without an applied voltage the film is transparent. Upon application of a voltage the liquid crystals align in such a way that the liquid crystals scatter light. This is more complex arrangement which may be less favored, as this arrangement may be less cost-effective. In both systems, it is common to apply an AC voltage in order to prevent or at least substantially reduce electromigration of the liquid crystal droplets.

In this way, the degree of transparency can be controlled and adjusted by the applied voltage. For example, at lower voltages, only a few of the liquid crystals align completely in the electric field, and/or the liquid crystals only partially align, so only a small portion of the light passes through unscattered whilst most of the light is scattered. As the applied voltage is increased, fewer liquid crystals remain out of alignment, resulting in less light being scattered. This is one way in which the material may be made to have the first translucence in the first state - i.e. the same translucence as the second region. Alternatives, such as a choice of a material having an intrinsic translucence equal to that of the second region in a particular state, will be familiar to the skilled person. PDLC materials have been commonly used for other applications, such as privacy control and are therefore well-known per se. Any suitable PDLC material may be used as the material of the first region 106.

The material may define a single pixel across the entire first region, in which case an electrode arrangement having a single pair of electrodes for addressing the full area of the material may be present; alternatively, the material may be pixelated in which case an electrode comprising a plurality of electrode pairs each arranged to address a separate region of the material may be present. In other words, where the material is pixelated the individual pixels may be addressed as in a display, in this way dynamic projections can be provided.

Alternatively, any other material may be used which is capable of being adjusted between at least a first state having the first translucence and a second state having a second translucence. Such materials for instance are commonly used in technical fields such as smart glasses or switchable glass technologies. A non-exclusive list of such technologies includes electrochromic, photochromic, thermochromic, suspended particle and micro-blind technologies.

The lighting device 100 also comprises a first set of solid state lighting elements 110 in said housing 102 for providing light to the first region 106, and a second set of solid state lighting elements 112 in said housing 102 for providing light to the second region 108. The first and second sets of solid state lighting elements 110,112 may each comprise only a single solid state lighting element; alternatively, at least one of these sets of solid state lighting elements, e.g. both sets, may comprise multiple solid state lighting elements. Where a set 110,112 comprises multiple solid state lighting elements, the solid state lighting elements may be arranged in an array. Another alternative is for each set to comprise a large pixelated solid state lighting element. The solid state lighting elements may be light emitting diodes (LEDs). The sets 110,112 of solid state lighting elements may be arranged to produce white light of any correlated color temperature (CCT). Alternatively, the sets 110,112 may be tuneable to provide a selected colored or white light. Other alternative sets and elements will be apparent to the skilled person.

Such a lighting device 100 may be operable in a number of different operation modes, e.g. in a first mode in which only the first set of solid state lighting elements 110 are switched on, a second mode in which both the first set of solid state lighting elements 110 and the second set of solid state lighting elements 112 are switched on, and optionally a third mode in which only the second set of solid state lighting elements 112 are switched on, wherein the material in the first region 106 may be adjusted to a state that is appropriate for the operating mode of the lighting device 100.

Throughout this specification, when a set of solid state lighting elements is referred to as being switched on, the luminous output may be adjusted or dimmed such that the set provides a particular luminous output for a desired lighting effect.

In an example embodiment, the lighting device 100 is configurable between a first mode in which the lighting device 100 is configured as a spot light and a second mode in which the lighting device 100 is configured to mimic an incandescent light bulb. In the first mode, only the first set of solid state lighting elements 110 are switched on and the first region 106 may be adjusted to a transparent state, i.e. the second translucence is a transparent state, thereby reducing the scattering of the light through the first region 106 such that a focused beam may be produced. One or more additional optical elements, e.g. one or more lenses, collimators or the like may be included in the design of the lighting device 100 to shape the luminous output produced in this first mode.

In the example second mode, both the first set of solid state lighting elements

110 and the second set of solid state lighting elements 112 are switched on, wherein the material of the first region 106 may be adjusted to a first translucent state such that both the first region and the second region have the same translucency, i.e. the first translucency, such that both groups of solid state lighting elements appear to operate as a single group of solid state lighting elements. For instance, the first translucency may be a diffusive or scattering state in which the bulbous light exit window 104 has a uniform appearance and in which the first set of solid state lighting elements 110 and the second set of solid state lighting elements 112 are obscured, i.e. cannot be directly observed. The appearance of the lighting device 100 may not be determined solely by the translucency of the first and second regions 106,108. As discussed above, the LEDs can also be dimmed to provide or enhance a particular luminous effect. For example, if it is desired for the first and second regions 106,108 to appear near identical, then the regions 106,108 should have the same luminous output. This may be achieved by adjusting the luminous output of the first and second sets of solid state lighting elements 110,112. The appearance of the lighting device 100 may also be governed by the luminance under different viewing angles. The angular dependence is governed, at least in part, by the scattering properties of the first and second regions 106,108. However, the luminance is governed, at least in part, by the total flux per unit surface area of the region 106,108 and hence is related to the amount of light coming from the sets of solid state lighting elements 110,112 - this can be adjusted by adjusting or dimming the luminous output of the sets of solid state lighting elements 110,112.

Such a lighting device 100 may further be considered to have a pleasing aesthetic. In particular, when in the aforementioned second mode, the bulbous light exit window 104 may appear uniform to a user, i.e. when the material of the first region 108 is in the first state such that it matches the translucence of the second region 108. Such an appearance may be advantageous in that it may be similar to that of a traditional incandescent light bulb having a pearl or frosted appearance.

In an embodiment, the lighting device 100 may exhibit such a pearl or frosted appearance when the lighting device 100 is in use, i.e. in the second mode, and also when the lighting device 100 is off, such that the lighting device 100 may mimic an incandescent light bulb in the off state, which may improve the marketability of the lighting device 100 e.g. when on the shelves of a retailer or advertised on the Internet. Additionally, during day time when there is sufficient ambient light and a lighting effect from the lighting device 100 is not needed, the lighting device 100 may have a particularly pleasing aesthetic, for example when it is visible inside a luminaire.

As will be apparent, such a lighting device 100 can provide a range of different lighting effects using only a single adjustable material and two sets of solid state lighting elements 110,112. Accordingly, the lighting device 100 may further comprise a controller 120 configured to switch the lighting device 100 between its different modes of operation. To this end, the controller is electrically connected to the electrode arrangement for adjusting the material of the first region 106, the first set of solid state lighting elements 110 and the second set of solid state lighting elements 112 respectively, wherein the controller 120 is configured to enable the appropriate set(s) of solid state lighting elements and adjust the material of the first region 106 to the desired state in accordance with the selected mode.

Alternatively, a controller may be omitted from the lighting device 100 and, for instance, the first set of solid state lighting elements 110, the second set of solid state lighting elements 112 and the material may be controlled by an external controller, in which case the lighting device 100 may comprise a plurality of control terminals for providing external control signals to the first set of solid state lighting elements 110, the second set of solid state lighting elements 112 and the material of the first region 106.

The controller 120 may be configured to receive configuration instructions and control the first and second sets of solid state lighting elements 110,112 and the material in accordance with said configuration instructions, as will be described in more detail below.

The second region 108 of the light exit window 104 may be formed of any suitable materials, as is known to the skilled person. In some embodiments it is preferred for the second region 108 of the light exit window 104 to have a relatively high translucence. For example, a frosted or coated glass or plastic may be used, e.g. a coated or etched glass or plastic material, a plastic material filled with scattering particles, a silicone polymer, and so on. The use of such materials allows the degree of first translucence to be accurately controlled. For example, by varying the type or thickness of the coating on the glass the translucency may be increased or decreased, e.g. a thicker coating can provide a greater translucence. As another example, by increasing the number of scattering particles within the plastic the translucence can be increased. Alternatively, the translucence may be varied, e.g. increased, by changing the scattering particle within the plastic or by changing the scattering particle plastic combination.

As a further alternative, the second region 108 of the light exit window 104 may be formed of a PDLC material. If the first region 106 of the light exit window 104 is also formed of a PDLC material, then this is another possible way of matching the translucence of the second region 108 and the first region 106 in the first state.

As illustrated in Fig. 3, where like reference numerals are used to designate like parts, the second region 108 of the light exit window 104 may surround the first region 106 of the light exit window 104. For example, the second region 108 of the light exit window 104 may be centered around the optical axis of the lighting device 100. Such a configuration can be used to provide a more focused light from the first region 106 and a less focused light from the first region 106 and the second region 108 together, as previously explained. In some embodiments the boundary where the first region 106 adjoins the second region 108 may not be visible as a distinct feature; this may be particularly

advantageous where an appearance comparable to a traditional incandescent light bulb is desired or preferred for reasons such as those discussed above. However, as illustrated in Fig. 3, in some embodiments the boundary 107 between the first region 106 and the second region 108 of the light exit window 104 may be visible.

As illustrated in Fig. 1, the lighting device may comprise an opaque wall structure 114 for confining the luminous output of the first set of solid state lighting elements 110 to the first region 106 and/or the luminous output of the second set of solid state lighting elements 112 to the second region 108. Such an arrangement prevents light from the first set of solid state lighting elements 110 from reaching the second region 108 of the light exit window 104 and also prevents light from the second set of solid state lighting elements 112 from reaching the first region 106 of the light exit window 104. Therefore this arrangement can enhance the contrast between the first region 106 and the second region 108 of the light exit window 104, when one of the respective regions is illuminated by the respective first or second set of solid state lighting elements 110,112 and the other respective region 106,108 is not illuminated by its respective set of solid state lighting elements 110,112.

The opaque wall structure 114 may be reflective, to reflect the luminous output of the first set of solid state lighting elements 110 towards the first region 106 of the light exit window 104 and/or the luminous output of the second set of solid state lighting elements 112 towards the second region 108 of the light exit window 104. This can help increase the overall luminous efficiency of the device by ensuring that more of the light emitted by the sets solid state lighting elements 110,112 reaches the respective region 106,108 of the light exit window 104.

The wall structure 114 may be shaped so as to provide chosen lighting effects; this may be particularly effective when the wall structure is reflective. For example, a reflective wall structure 114 may be shaped so as to provide spot lighting from the first region 106 of the light exit window 104, for example, by having a net concentrating or focusing effect. A specularly reflective wall structure 114 may be provided by e.g. an aluminum coating on the wall structure 114. The combination of a specularly reflective wall structure 114 which is also shaped so as to provide spot lighting may be particularly preferred where a very narrow spot beam effect is desired.

In some embodiments, the wall structure 114 is diffusely reflective, for example the wall structure 114 may be made of or coated with a white plastic material. When the wall structure 114 is diffusely reflective, light will be scattered when reflected, therefore a broader spot beam may be provided than with a specularly reflective wall structure 114, which may be preferred for some applications.

Additionally or alternatively, a reflective wall structure 114 may be shaped so as to provide ambient lighting from the second region 108 of the light exit window 104, for example by having a net dispersing or wide angle effect.

The provision of spot and/or ambient lighting by embodiments of the lighting device 100 is a particularly interesting application of the lighting device 100. For example, where the second state is transparent and the material is in the second state, the first set of solid state lighting elements is on and the second set of solid state lighting elements is off, a spot light function may be provided. An alternative, more diffuse, spot light function may be provided where the first state is translucent and the material is in the first state, the first set of solid state lighting elements is on and the second set of solid state lighting elements is off - as will be apparent to the skilled person, when the material is adjusted to a translucent state, the first region 106 of the light exit window will scatter light resulting in the provision of a more diffuse spot light.

Ambient light may be provided where the first state is relatively highly translucent, e.g. diffusive or scattering, the material is in the first state and the first and second sets of solid state lighting elements 110,112 are on. As in this configuration both the first and second regions 106,108 of the light exit window are highly translucent, the sets of solid state lighting elements 110,112 may not be directly visible and/or glare from the lighting device 100 may be reduced or eliminated. In particular lighting applications glare may be undesired, as will be apparent to the skilled person, accordingly, such a lighting device and configuration may be advantageous from an aesthetic appearance point of view. The luminous output of the sets of solid state lighting elements 110,112 may also be adjusted to provide such a lighting effect, as discussed above.

In an embodiment, the controller 120 is configured to receive configuration instructions and to control the first and second set of solid state lighting elements 110,112 and the material in accordance with the received configuration instructions. The

configuration instructions may comprise on/off instructions and/or light intensity levels for the first and second set of solid state lighting elements 110,112 and adjusting instructions for the adjustable material. Alternatively, the configurations instructions may comprise a desired lighting effect, in which case the controller may be adapted to process the configuration instructions in order to determine intensity levels for the first and second set of solid state lighting elements 110,112 and a adjusting state for the adjustable material and to control the first and second set of solid state lighting elements 110,112 and the material accordingly.

The controller 120 may include a receiver for wirelessly receiving the configuration instructions. In this embodiment, the lighting device 100 may further comprise an antenna functionally (not shown) connected to the controller 120, wherein the antenna is configured to wirelessly receive said configuration instructions and relay the received configuration instructions to the receiver of the controller 120. This can simplify retrofitting of the lighting device into fittings for traditional lighting devices, such as incandescent light bulbs. For example, the lighting device 100 may comprise a bayonet fitting or Edison screw fitting to receive power and the configurations of the light output from the device may be controlled wirelessly. Such an installation may be simple and therefore cost-effective. Any suitable wireless communication protocol may be used for the wireless communication with the lighting device 100, e.g., an infrared link, Zigbee, Bluetooth, a wireless local area network protocol such as in accordance with the IEEE 802.11 standards, a 2G, 3G or 4G telecommunication protocol, any suitable proprietary protocol, and so on.

Alternatively, the lighting device 100 may be configured by wired communication, in which case the controller 120 may include a receiver for receiving the configuration instructions in a wired fashion. For example, one or more dedicated wires may be supplied to the lighting device 100 in order to provide the lighting device 100, i.e. the controller 120, with such configuration instructions. As another example, configuration instructions may be transmitted to the lighting device 100 by modulating the power signal supplied to the lighting device 100, wherein the modulation includes the configuration instructions. Such an arrangement may obviate the need for the installation of additional wires to the location in which the lighting device 100 is to be fitted.

As illustrated in Fig. 4, one or more lighting devices 100 according to any embodiment of the invention may be advantageously included in a luminaire 200 such as a holder of the one or more lighting devices 100, e.g. a ceiling light fitting, a light fitting for illuminating a picture or other artwork installation, and so on. Fig. 4 schematically depicts a luminaire 200 comprising a single lighting device 100 fitted in a housing 210 of the luminaire 200 by way of non-limiting example only. The luminaire 200 comprises a light exit window 220, which may simply be formed by an opening in the housing 210 or alternatively may include some optical material, e.g. an optical grade glass or polymer to protect the lighting device 100 in the luminaire 200 from accidental damage. Fig. 5 depicts a flow chart of a method 400 for configuring the lighting device 100. The method 400 starts in step 402 which may include powering up systems for implementing the method, such as switching on a control device used for configuring the lighting device 100. The method subsequently proceeds to step 404, in which user inputs are received on the control device, for example through a user interface (UI). The user for instance may provide configuration instructions for configuring the first set of solid state lighting elements 110, the second set of solid state lighting elements 112 and the material of the lighting device 100 in step 404, e.g. by selecting a predefined operating mode of the lighting device 100 or by actually defining the desired operating mode.

The user may provide configuration instructions in step 404 which comprise instructions to co-ordinate the lighting configuration to operate in tandem with other lighting configurations, e.g. lighting configurations of further devices, for example, lighting devices which provide colored or other effects. Additionally or alternatively, the user may provide instructions to provide a selected colored or white light. Additionally or alternatively, the user may provide instructions to configure the lighting device in response to a timer, for example, to provide a particular lighting configuration at 6am to function as an alarm clock. Additionally or alternatively, the user may provide instructions in step 404 to configure the lighting device in response to a notification such as a text message or an e-mail in order to notify a user of such an occurrence.

The configuration instructions are subsequently transmitted in step 406 to the lighting device 100. In response to receiving the configuration instructions, the controller 120 of the lighting device 100 may accordingly configure the lighting device 100 in step 408, after which the method terminates in step 410.

As illustrated in Fig. 6, the method 400 may be a computer-implemented method stored on a computer program product 500 comprising a computer-readable storage medium 502 embodying computer program code 504 for, when executed on one or more processors of a computing device, implementing the method 400 of configuring a lighting device. In an embodiment, the computer program product 500 may be made available on a server, e.g. hosting an application store, in which case the computer program code 504 may come as an app to be installed on the computing device 600.

Fig. 7 schematically depicts an example embodiment of such a computing device 600 including at least one processor 602 and the computer program product 500, wherein the at least one processor 602 is adapted to execute the computer program code 504 of said product 500. The computing device 600 may further comprise a user interface 604 for receiving user instructions, as will be familiar to the skilled person. Any suitable user interface, e.g. a keypad, touch screen, a movement sensor such as a gyroscope for detecting a movement-based user instruction, e.g. a head, hand or arm movement or the like, an image sensor for capturing a gesture-based user instruction, and so on may be considered.

The computing device 600 may further comprise an antenna 606 for wirelessly transmitting configuration instructions to the lighting device 100, as is known in the art.

The computing device may be any one of a large number of different computing devices. Consumer electronics devices having significant computing power for executing the computer program product have increased in popularity, such that it is common for an individual to own a number of such devices. A particularly prevalent computing device suitable for executing the computer program product is a mobile phone, which has the advantage of being portable and often readily available to a user.

The computing device alternatively may be selected from the group consisting of a phablet, a tablet, a desktop computer, a laptop computer, a personal organizer, a music player and a dedicated lighting controller. These devices are prevalent and readily available in a number of environments.

The lighting device 100 according to any embodiment of the invention may advantageously be included in a lighting system comprising the lighting device 100. The lighting system may further comprise the computer program product and/or the computing device described above. Additionally or alternatively the lighting system may further comprise other lighting devices, e.g. lighting devices which provide different effects, e.g. colored effects, such as those available as part of the Philips Hue system. The system may also comprise bridge units for interfacing between proprietary wireless networks specifically designed to connect multiple lighting devices together and conventional (wireless) home networks, such as Wi-Fi networks.

Aspects of the present invention may be embodied as a lighting device, luminaire, method, computer program product, computing device and/or lighting system. Aspects of the present invention may take the form of a computer program product embodied in one or more computer-readable medium(s) having computer readable program code embodied thereon.

Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Such a system, apparatus or device may be accessible over any suitable network connection; for instance, the system, apparatus or device may be accessible over a network for retrieval of the computer readable program code over the network. Such a network may for instance be the Internet, a mobile communications network or the like. More specific examples (a non- exhaustive list) of the computer readable storage medium may include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of the present application, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Computer program code for carrying out the methods of the present invention by execution on at least one processor of a computing device may be written in any combination of one or more programming languages, including an object oriented

programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the at least one processor as a stand- alone software package, e.g. an app, or may be executed partly on the at least one processor and partly on a remote server. In the latter scenario, the remote server may be connected to the computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer, e.g. through the Internet using an Internet Service Provider. Aspects of the present invention are described above with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions to be executed in whole or in part on the at least one processor of the computing device, such that the instructions create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a computer-readable medium that can direct computing device to function in a particular manner.

The computer program instructions may be loaded onto the at least one processor to cause a series of operational steps to be performed on the at least one processor, to produce a computer-implemented process such that the instructions which execute on the at least one processor provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. The computer program product may form part of a computing device 100, e.g. may be installed on the computing device.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several distinct elements. A single controller, processor or other unit may fulfil the functions of several items recited in the claims. A computer program may be

stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. In the device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.