Patent Description:
The invention further relates methods of controlling lighting devices to provide immersive, natural lighting conditions as found in an outdoor environment in an indoor environment.

In an outdoor environment, the interaction of natural daylight with its ambient environment results in all kinds of light across the sky and vegetation, with the dynamics, patterns, tonalities and intensities of the light being dependent upon geographic location, season, weather and time of day. Frequently, however, humans do not observe this interaction consciously, simply because the constant cycles and variation of nature are an integral part of humans' natural evolution and habitat. Nevertheless, humans are strongly connected to the emotional and biological benefits of natural light.

In an indoor environment, such as in (deep) open plan offices and hospitality areas, humans' access to natural light may be limited. For example, because persons are seated too far away from a window or because there is only a small window allowing little light in or because the natural light is diffuse (solar tube, milky glass, fog) or because there is no access to natural light at all. In all these cases, humans become to a greater or lesser extent disconnected from the constant cycles and variation nature.

In spaces (partially) deprived of natural light, the dynamics that are present in the outdoor environment are missing. Conventional lighting in an indoor environment, such as in an office building, is often static. Control options may be limited to on/off control or control of a dimming level (e.g. allowing dimming up to increase light intensity or dimming down to lower light intensity).

Conventional lighting devices are arranged in a grid-like structure and controlled individually or as a group in which they are controlled in an identical fashion (e.g. all on/off, all to a specific dimming level or all to a relative dimming level compared to a neighboring lighting device). Generally, the same type of lighting devices is used in a single room or zone. For example, an office space may comprise panel lighting fixtures of the same type in each room except for the corridor where downlights are used. To address different light level needs, the number of lighting devices and/or their placement may be adapted.

Light transmitting structures, such as (real) skylights, (real) windows and the like may be used to increase the amount of daylight that enters an indoor environment. Although light transmitting structures can increase a feeling of well-being of inhabitants of the indoor environment, they are costly and cannot be installed everywhere. Further, they may cause other issues, such as privacy and safety issues.

Artificial skylights and artificial windows have been proposed as a solution, as well as dynamic and static displays showing a view of clouds passing in the sky or other natural elements (e.g. a view of the forest or sea). However, these may actually draw attention to the fact that one is in an indoor environment and have an opposite effect, i.e. lower the feeling of well-being.

<CIT> discloses a natural daylight mimicking system and user interface, wherein a selection indicator has a plurality of indicators associated with light settings which change as a function of time to point to different indicators and change the light attributes in accordance with the currently aligned indicator.

<CIT> discloses a lighting system for dynamic lighting control, wherein the control device has a plurality of one-dimensional user setting, a predetermined sequence of light parameters as a function of time, and an adjustment to the predetermined sequence as a function of a selected one-dimensional user setting.

<CIT> discloses resuming a dynamic light effect in dependence on an effect type and/or user preference.

It is a first object of the invention to provide a system, which is able to provide enhanced emulation of (aspects of) an outdoor environment in an indoor environment.

It is a second object of the invention to provide a method, which is able to provide enhanced emulation of (aspects of) an outdoor environment in an indoor environment.

In a first aspect of the invention, a system for controlling a plurality of lighting devices to provide an illumination of an environment according to a dynamic light scene, comprises at least one input interface, at least one output interface, and at least one processor configured to determine, from said dynamic light scene, a plurality of light effects to be rendered by one or more of said plurality of lighting devices, said plurality of light effects corresponding to a first moment in said dynamic light scene, said dynamic light scene specifying a temporal sequence of light effects for each of said plurality of lighting devices, and control, via said at least one output interface, said one or more lighting devices to render said plurality of light effects.

Said at least one processor is further configured to receive a user input signal via said at least one input interface, determine a second moment in said dynamic light scene based on said user input signal, determine a transition from said first moment to said second moment, said transition being faster than a normal transition from said first moment to said second moment, as specified in said dynamic light scene, determine, from said dynamic light scene, a plurality of further light effects to be rendered by said one or more lighting devices, said plurality of further light effects corresponding to said second moment in said dynamic light scene, and control, via said at least one output interface, said one or more lighting devices to render said plurality of further light effects after said transition.

In many situations, it is possible to render a dynamic light scene without user interaction being required. However, under certain circumstances, e.g. because the use case of a given space changes, because of a change in organizational rhythm (e.g. a deviation from the normal <NUM>:<NUM> - <NUM>:<NUM> working hours), or simply because of a need for a different light scene (to e.g. relax, focus or socialize), a manual override of the content playing across a plurality of different lighting devices, may be demanded, desired and wished for.

One straightforward method to accomplish a change in a given light scene is to simply play another light scene. Another option is to change one or more of the individual settings, but this would normally result in the dynamic light scene rendering stopping. If the dynamic light scene is rendered by a dynamic lighting program, the user may be allowed to change the many parameters that define the dynamic light scene. However, for a human controller, having access to a multiple-button (remote) control, correct and natural matching and mapping of all the interdependent rendering parameters (simultaneously) is an impossible task. Not only in terms of understanding the system complexity, but also in terms of the design of an intuitive user-interface (UI).

It is effective, intuitive and useful to allow humans to control only, and only one light scene parameter for the current scene and it is very intuitive to allow the user to be able to change the moment in a dynamic light scene, e.g. in a dynamic light scene that mimics the light conditions outside or in a firelight scene. The moment in the dynamic light scene may correspond to a time of day, for example. Thus, when only wanting to advance through the time of day, for example for an otherwise clam and sunny day, there is no need to change the rate of dapple or the rate of (pattern) transition or any other subscene other than, for example, that or those involved in the colors and tonalities of the skylight and/or the accent/peripheral light(s).

Said transition is immediate for at least a first subset of said one or more lighting devices. Said transition is gradual for at least a second subset of said one or more lighting devices. In the latter case, said at least one processor is configured to determine one or more intermediate light effects to be rendered by said second subset of lighting devices, each of said one or more intermediate light effects corresponding to a moment between said first moment and said second moment in said dynamic light scene, and control, via said at least one output interface, said second subset of lighting devices to render said one or more intermediate light effects during said transition. The processor may determine said first subset and said second subset of said plurality of lighting devices. The processor may determine for each lighting device of said plurality of lighting devices whether it is part of the first subset or the second subset (or neither the first subset nor the second subset), and may determine such based on e.g. the type of lighting device, the position and/or orientation of a lighting device, an identifier or association of a lighting device, past use of a lighting device or based on a setting provided by a user. This allows certain lighting devices to be part of the first subset, which will immediately transition to the further light effects, and other lighting devices to be part of the second subet, which will render intermediate light effects prior to transition to the furher light effects.

Like in music, abrupt changes in a given light scene can be very disruptive, in particular to those not in control of the light scene change (and possibly not even expecting a change). Further, a (too) rapid change of content can cause disruptive modulation in the (local) light level(s) across the space, unnecessarily distracting office workers from their tasks. Therefore, changes in a light scene should preferably be brought about gradually and smooth, and without noticeable flicker, hick-ups, bumps or jumps.

However, since the different rhythms and cycles of nature (circadian, semantic patterns and light effects like e.g. dapple) are running at the same time, but at different rates of change and scale, "equalizing", "fast-forwarding" or even "reversing" all rhythms at the same time can be very disruptive and even feel alarming. Therefore, different light effects may have different transition durations.

Said at least one input interface may comprise a control device with a one-dimensional control element or an interface to said control device. Said control element may, for example, be rotatable, e.g. continuous rotatable. If said control element is a continuous rotatable control element, a time difference between said second moment and said first moment may be determined based on a rotation of said continuous rotatable control element with the time difference between said second moment and said first moment being relative to the value of time at said first moment, for example. Said control device may comprise a display and said control device may be configured to display a representation of said first moment and/or said second moment in said dynamic light scene on said display. Instant feedback should preferably be provided to the human controller in real-time.

Said user input signal may be indicative of a time difference between said first moment and said second moment and/or indicative of a desire to go forward in time in said dynamic light scene or indicative of a desire to go backward in time in said dynamic light scene.

Said at least one processor may be configured to determine, from said dynamic light scene, at least one subsequence of light effects to be rendered by at least one other lighting device of said plurality of lighting devices, a first plurality of light effects of said at least one subsequence corresponding to a third moment in said dynamic light scene and a second plurality of light effects of said at least one subsequence corresponding to a fourth moment in said dynamic light scene, a time difference between said first moment and said third moment being different than a time difference between said second moment and said fourth moment, and control said at least one other lighting device to render said at least one subsequence of light effects of light effects, said at least one other lighting device being controlled to render said first plurality of light effects while said one or more lighting devices are being controlled to render said plurality of light effects and said at least one other lighting device being controlled to render said second plurality of light effects while said one or more lighting devices are being controlled to render said plurality of further light effects. Thus, a first set of lighting devices renders the same dynamic light scene as a second set of lighting devices, but with a delay. This delay can be adjusted.

Said at least one processor may be configured to determine a further plurality of light effects to be rendered by at least one other lighting device of said plurality of lighting devices, said further plurality of light effects corresponding to a third moment in said dynamic light scene, said third moment being different than said first moment, control, via said at least one output interface, said at least one other lighting device to render said further plurality of light effects, determine a fourth moment in said dynamic light scene based on said user input signal, said fourth moment being different than said second moment and a time difference between said first moment and said third moment being equal to a time difference between said second moment and said fourth moment, determine a transition from said third moment to said fourth moment, said transition being faster than a normal transition from said third moment to said fourth moment, as specified in said dynamic light scene, determine a further plurality of further light effects to be rendered by said at least one lighting device, said further plurality of further light effects corresponding to said fourth moment in said dynamic light scene, and control, via said at least one output interface, said at least one other lighting device to render said further plurality of further light effects after said transition. Thus, a first set of lighting devices renders the same dynamic light scene as a second set of lighting devices, but with a delay. When the user forwards or reverses to another moment, this is applied to both sets of lighting devices and the delay stays the same.

Said dynamic light scene may represent a daylight scene and said first moment and said second moment may correspond to different times of a day, for example. Said dynamic light scene may represents a firelight scene and said first moment and said second moment may correspond to different scales of a fire, for example. Said dynamic light scene may represent a forest scene and said first moment and said second moment may correspond to different tree and/or leaf densities, for example.

Said at least one processor may be configured to determine one or more values of one or more further parameters based on said user input signal, adapt at least one of said plurality of further light effects to be rendered by said one or more lighting devices based on said one or more values and control said one or more lighting devices to render said adapted at least one further light effect after said transition.

Said plurality of lighting devices may comprise a peripheral lighting device for providing dynamic and vertical illumination, an artificial skylight and a functional general lighting device for providing horizontal light.

In a second aspect of the invention, a method of controlling a plurality of lighting devices to provide an illumination of an environment according to claim <NUM>.

Said method may be performed by software running on a programmable device. This software may be provided as a computer program product.

A non-transitory computer-readable storage medium stores at least a first software code portion, the first software code portion, when executed or processed by a computer, being configured to perform executable operations for controlling a plurality of lighting devices to provide an illumination of an environment according to a dynamic light scene.

The executable operations comprise determining, from said dynamic light scene, a plurality of light effects to be rendered by one or more of said plurality of lighting devices, said plurality of light effects corresponding to a first moment in said dynamic light scene, said dynamic light scene specifying a temporal sequence of light effects for each of said plurality of lighting devices, controlling said one or more lighting devices to render said plurality of light effects, receiving a user input signal, and determining a second moment in said dynamic light scene based on said user input signal.

The executable operations further comprise determining a transition from said first moment to said second moment, said transition being faster than a normal transition from said first moment to said second moment, as specified in said dynamic light scene, determining, from said dynamic light scene, a plurality of further light effects to be rendered by said one or more lighting devices, said plurality of further light effects corresponding to said second moment in said dynamic light scene, and controlling said one or more lighting devices to render said plurality of further light effects after said transition. Said method may be performed by software running on a programmable device. This software may be provided as a computer program product.

A non-transitory computer-readable storage medium stores at least a fourth software code portion, the fourth software code portion, when executed or processed by a computer, being configured to perform executable operations for controlling a lighting arrangement, wherein said lighting arrangement comprises an artificial skylight and a functional general lighting device for providing horizontal light, said functional general lighting device comprising a horizontal luminous surface, said functional general lighting device being positioned in parallel and adjacent to said artificial skylight, and a spacing between said functional general lighting device and said artificial skylight not exceeding the width of said artificial skylight.

The executable operations comprise controlling said artificial skylight and said functional general lighting device to render different light effects of a dynamic light scene, said dynamic light scene specifying a temporal sequence of light effects for each of a plurality of lighting devices, said plurality of lighting devices including said artificial skylight and said functional general lighting device. Said method may be performed by software running on a programmable device. This software may be provided as a computer program product.

Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical (e.g. a visible light communication signal), or any suitable combination thereof.

<FIG> shows an embodiment of the system: a controller <NUM>, e.g. a gateway or a bridge, of a NatureConnect lighting system <NUM>. The controller <NUM> comprises a receiver <NUM>, a transmitter <NUM>, a processor <NUM>, and memory <NUM>. NatureConnect is a system that delivers a compelling light experience by creating spaces that connect users with the constant cycles and variation of nature. NatureConnect changes the way how light is created in professional environments, as traditionally, the light generation in these spaces is functional and static.

With NatureConnect, a move is made away from functional illumination to natural light for inspiring environments and enhanced well-being and from static to dynamic and <NUM>-dimensional for an immersive light experience. In this immersive light experience, a plurality of lighting devices, typically multiple kinds of lighting devices, including pixelated lighting devices, work together in one lighting system to provide a wide range of dynamic light scenes, with lighting arrangements <NUM> and <NUM> providing a realistic view to the sky, lighting arrangements <NUM> and <NUM> providing functional light, and peripheral lighting devices <NUM>-<NUM> providing natural feeling patterns, dynamics and tonalities of vertical illumination. Lighting arrangement <NUM> is an artificial skylight. Lighting arrangement <NUM> comprises an artificial skylight and light elements for providing functional light. In the embodiment of <FIG>, lighting arrangement <NUM> is a canopy lighting device. The lighting devices are typically pixelated lighting devices.

A NatureConnect system is typically able to display dynamic and natural feeling content at (locally) different rates, scales and resolution. This offers an opportunity to more easily add a semantic meaning to the content played in using specific colors, dynamics and patterns. An example of natural feeling content is a dapple light effect, representing the shadow play of the sun's light rays falling through a canopy of (moving) tree leaves. Other examples of natural feeling content are the patterns and color gradients at the walls mimicking the natural sky gradient, as well as the set of colors of the sky and sun in the artificial skylight, albeit displayed at different levels of brightness, pixelation and resolution (when compared to, for example, dapple).

In a NatureConnect system, multiple light effects (comprising the different rhythms and cycles of nature) are rendered simultaneously by each of a plurality of lighting devices, wherein the multiple light effects are typically determined based on a (at least partially) predetermined dynamic lighting program which is mapped to a time period by means of a processor, e.g. processor <NUM>, such that the dynamic lighting scene changes as time progresses. As such, the lighting system operates in a natural feeling manner and can operate without the need for user interaction. Alternatively or additionally, a NatureConnect system may be able to render pre-stored dynamic light scenes. In the embodiment of <FIG>, the rendering of the light effects is coordinated centrally, by controller <NUM>.

Lighting arrangement <NUM> is shown in more detail in <FIG>. Lighting arrangement <NUM> comprises three artificial skylights <NUM>-<NUM> and four functional general lighting devices <NUM>-<NUM> for providing horizontal light. Each of the functional general lighting devices <NUM>-<NUM> comprises a horizontal luminous surface. The functional general lighting devices <NUM> and <NUM> are positioned in parallel and adjacent to the artificial skylights <NUM>-<NUM>, each on a different side of the artificial skylights <NUM>-<NUM>. A spacing between the functional general lighting devices <NUM> and <NUM> and the artificial skylights <NUM>-<NUM> does not exceed the width of the artificial skylights <NUM>-<NUM>. The artificial skylights <NUM>-<NUM> and the functional general lighting devices <NUM>-<NUM> have a width and a length in the horizontal direction and a height or depth in the vertical direction. The width is smaller than the length.

Optionally, the parallel arrangement of artificial skylights <NUM>-<NUM> and functional general lighting devices <NUM> and <NUM> is "capped" at least at one end by means of a second large luminous surface. In the embodiment of <FIG>, the functional general lighting device <NUM> is a first edge functional general lighting device adjacent to a first end of the artificial skylight <NUM> in the length direction and the functional general lighting device <NUM> is a second edge functional general lighting device adjacent to a second end of the artificial skylight <NUM> in the length direction.

In the embodiment of <FIG>, the width of the functional general lighting devices <NUM> and <NUM> is at least half of the width of the artificial skylights <NUM>-<NUM> and the spacing between the functional general lighting devices <NUM> and <NUM> and the artificial skylights <NUM>-<NUM> does not exceed five centimeters.

<FIG> shows a perspective view of room in which the lighting arrangement <NUM> of <FIG> has been mounted. In the example of <FIG>, the lighting arrangement <NUM> is suspended from a ceiling. In this way, the lighting arrangement looks like a "stand-alone" island. Although an installer is able to distribute the different lighting devices of a system like NatureConnect as he or she pleases along an existing suspended ceiling grid, the experience of an in grid installation is not as powerful as that of a cluster of lighting devices coming in the form of an "island", for example suspended from an open or closed ceiling. This because a grid "puts" an additional raster feel towards the installation.

The lighting arrangement <NUM> has an island finishing peripheral rim, which is preferably black. By using a height of the artificial skylight that is larger than the height of the island finishing peripheral rim, the level of illusion of the artificial skylight and structural feel of the ceiling may be increased. The peripheral lighting device <NUM> suspended from the lighting arrangement <NUM> and arranged in proximity to at least one of the office walls and illuminates at least one office wall. In an alternative embodiment, the peripheral lighting device <NUM> is attached to the lighting arrangement <NUM>. The functional general lighting devices <NUM>-<NUM> illuminate a table <NUM> in the room.

In the alternative embodiment shown in <FIG>, a lighting arrangement <NUM> is similar to the lighting arrangement <NUM> of <FIG>, but without edge functional general lighting devices <NUM> and <NUM>. In the alternative embodiment shown in <FIG>, a lighting arrangement <NUM> is similar to the lighting arrangement <NUM> of <FIG>, but without functional general lighting device <NUM>.

The controller <NUM> performs at least one of a plurality of functions. If the controller is able to perform a first function, the processor <NUM> is configured to control the artificial skylights <NUM>-<NUM>, the functional general lighting devices <NUM>-<NUM>, and the peripheral lighting device <NUM> to render different light effects of a dynamic light scene. The dynamic light scene specifies a temporal sequence of light effects for each of a plurality of lighting devices. The plurality of lighting devices includes the artificial skylights <NUM>-<NUM>, the functional general lighting devices <NUM>-<NUM>, and the peripheral lighting device <NUM>.

In the embodiment of <FIG>, the processor <NUM> is also configured to control the peripheral lighting device <NUM>-<NUM>, the artificial skylight <NUM>, and the functional general lighting device <NUM>, either to render different light effects of the same dynamic light scene or to render different light effects of a different dynamic light scene.

In the embodiment of <FIG>, the processor <NUM> is configured to control the functional general lighting devices <NUM>-<NUM> at a light level that is harmonized to a light level at which the artificial skylights <NUM>-<NUM> are controlled. In the embodiment of <FIG>, the processor <NUM> is configured to control the artificial skylights <NUM>-<NUM> to render blue and/or cyan light and the functional general lighting devices <NUM>-<NUM> to render light with a color temperature between <NUM> Kelvin and <NUM> Kelvin.

The artificial skylights <NUM>-<NUM> of <FIG> each comprise a light emitting surface and may further comprise a light emitting inner rim surrounding the light emitting surface, which is perpendicular to the light emitting surface. An example of such a light emitting rim is shown in <FIG>. In this case, the dynamic light sequence may specify the light effects for the light emitting surface and the light emitting inner rim of an artificial skylight separately. The processor <NUM> may be configured to control the light emitting inner rims of the artificial skylights to render a shadow effect along at least part of the inner rim. Alternatively, a backlit inner rim may comprise a (static) hard shadow mask at the front of the backlit inner rim to yield a shadow effect.

Lighting arrangement <NUM> is shown in more detail in <FIG>. Lighting arrangement <NUM> does not comprise any functional general lighting device, but only artificial skylights <NUM>-<NUM>. Each of the artificial skylights <NUM>-<NUM> comprises a light emitting surface and a light emitting inner rim surrounding the light emitting surface. The light emitting inner rim is perpendicular to the light emitting surface. The light emitting inner rim may be used to emulate sun struck portions of a rim of a real skylight.

Artificial skylight <NUM> comprises a light emitting surface <NUM> and light emitting inner rim <NUM>. Artificial skylight <NUM> comprises a light emitting surface <NUM> and light emitting inner rim <NUM>. Artificial skylight <NUM> comprises a light emitting surface <NUM> and light emitting inner rim <NUM>. <FIG> shows a perspective bottom view of the lighting arrangement <NUM> of <FIG>.

If the controller <NUM> is able to perform a second function, the processor <NUM> is configured to determine a dynamic light scene and control, via the transmitter <NUM>, the light emitting surfaces <NUM>-<NUM> (also referred to as skylight panels), the light emitting inner rims <NUM>-<NUM> (also referred to as frames), the functional general lighting device <NUM> (also referred to as canopy lighting device), and the peripheral lighting device <NUM> to render the dynamic light scene. The dynamic light scene specifies a temporal sequence of light effects for each of a plurality of lighting devices. The plurality of lighting devices comprises the light emitting surfaces <NUM>-<NUM>, the light emitting inner rims <NUM>-<NUM> and the functional general lighting device <NUM>. The functional general lighting device <NUM> comprises a horizontal luminous surface.

A light intensity level of the light effect for the light emitting surfaces <NUM>-<NUM> at a first moment in the dynamic light scene is higher than a light intensity level of the light effect for the light emitting surface <NUM>-<NUM> at a second moment in the dynamic light scene, a light intensity level of the light effect for the light emitting inner rims <NUM>-<NUM> at the first moment is higher than a light intensity level of the light effect for the light emitting inner rims <NUM>-<NUM> at the second moment, a light intensity level of the light effect for the functional general lighting device <NUM> at the first moment is higher than a light intensity level of the light effect for the functional general lighting device <NUM> at the second moment.

A color temperature of the light effect for the light emitting surfaces <NUM>-<NUM> at the first moment is higher than a color temperature of the light effect for the light emitting surfaces <NUM>-<NUM> at the second moment, a color temperature of the light effect for the light emitting inner rims <NUM>-<NUM> at the first moment is higher than a color temperature of the light effect for the light emitting inner rims <NUM>-<NUM> at the second moment, a color temperature of the light effect for the functional general lighting device <NUM> at the first moment is higher than a color temperature of the light effect for the functional general lighting device <NUM> at the second moment.

In an experiment, on switching on the artificial skylight, although hardly providing any functional light, the space opened up and felt spacious when setting the color temperatures and light intensity levels as described above. Furthermore, by matching the color temperature of the sun struck portion of the inner rim (frame) with the color temperature of functional general lighting device (canopy), the spaciousness was further increased, and a more natural feel was provided. Moreover, when the color of the artificial sky in the skylight was set to deeper blue (><NUM>), the color temperature of the functional light could be increased well beyond <NUM> without feeling uncomfortable.

The first moment may correspond to solar noon and the second moment may correspond to sunrise, a moment between sunrise and at most an hour after sunrise, sunset, or a moment between at most an hour before sunset and sunset, for example. The hour after sunrise and the hour before sunset are also referred to as golden hours.

In the embodiment of <FIG>, the processor <NUM> of the controller <NUM> is configured to ensure that a difference between the color temperature of the light effect for the functional general lighting device <NUM> and the color temperature of the light effect for the light emitting inner rims <NUM>-<NUM> stays below <NUM> Kelvin at the first moment, at the second moment, and at any moment between the first moment and the second moment.

In the embodiment of <FIG>, the processor <NUM> of the controller <NUM> is configured to ensure that the color temperature for the light emitting surfaces <NUM>-<NUM> stays above <NUM> Kelvin at the first moment, at the second moment, and at any moment between the first moment and the second moment.

In the embodiment of <FIG>, the processor <NUM> of the controller <NUM> is configured to ensure that the color temperature of the light effect for the light emitting surfaces <NUM>-<NUM> at the first moment is higher than or equal to the color temperature of the light effect for the functional general lighting device <NUM> at the first moment, and the color temperature of the light effect for the light emitting surfaces <NUM>-<NUM> at the first moment is higher than or equal to the color temperature of the light effect for the light emitting inner rims <NUM>-<NUM> at the first moment.

In the embodiment of <FIG>, the processor <NUM> of the controller <NUM> is configured to ensure that the light intensity level of the light effect for the light emitting surfaces <NUM>-<NUM> at the first moment is higher than the light intensity level of the light effect for the light emitting inner rims <NUM>-<NUM> at the first moment, and the light intensity level of the light effect for the light emitting surfaces <NUM>-<NUM> at the first moment is higher than the light intensity level of the light effect for the functional general lighting device <NUM> at the first moment.

<FIG> shows an example of color temperature changes from a first moment <NUM>, e.g. solar noon, to a second moment <NUM>, e.g. sunset, of different lighting devices participating in a dynamic light scene. The dynamic light scene represented in <FIG> corresponds to a normal sunny day. In <FIG>, color temperatures <NUM> are rendered by the light emitting surface(s) of the artificial skylight(s), color temperatures <NUM> are rendered by the functional general lighting device(s), and color temperatures <NUM> are rendered by the light emitting inner rim(s) of the artificial skylight(s).

In the example of <FIG>, the color temperature <NUM> of the light effect for the light emitting surface(s) at the first moment <NUM> is higher than the color temperature <NUM> of the light effect for the functional general lighting device(s) at the first moment <NUM>, and the color temperature <NUM> of the light effect for the functional general lighting device(s) at the first moment <NUM> is higher than the color temperature <NUM> of the light effect for the light emitting inner rim(s) at the first moment <NUM>.

In the example of <FIG>, a first difference <NUM> between the color temperature <NUM> of the light effect for the functional general lighting device and the color temperature <NUM> of the light effect for the light emitting inner rim exceeds <NUM> Kelvin and a second difference <NUM> between the color temperature <NUM> of the light effect for the light emitting surface and the color temperature <NUM> of the light effect for the functional general lighting device exceeds the first difference <NUM> multiplied by two.

In the example of <FIG>, the color temperature <NUM> of the light effect for the light emitting surface(s) at the second moment <NUM> is higher than the color temperature <NUM> of the light effect for the light emitting inner rim(s) at the second moment <NUM>, and the color temperature <NUM> of the light effect for the light emitting inner rim(s) at the second moment <NUM> is higher than the color temperature <NUM> of the light effect for the functional general lighting device(s) at the second moment <NUM>.

In the example of <FIG>, the color temperatures <NUM> of the light effects for the light emitting surface do not increase between the first moment <NUM> and the second moment <NUM> and the color temperatures <NUM> of the light effects for the functional general lighting device do not increase between the first moment <NUM> and the second moment <NUM>.

Corresponding light intensity levels are not shown in <FIG>, but the light intensity level of the light effect for the light emitting surface(s) at the first moment <NUM> is preferably higher than the light intensity level of the light effect for the light emitting inner rim(s) at the first moment <NUM>, and the light intensity level of the light effect for the light emitting inner rim(s) at the first moment <NUM> is preferably higher than the light intensity level of the light effect for the functional general lighting device(s) at the first moment <NUM>.

Preferably, the light intensity level of the light effect for the light emitting surface(s) at the second moment is higher than the light intensity level of the light effect for the light emitting inner rim(s) at the second moment, and a difference between the light intensity level of the light effect for the light emitting inner rim(s) at the second moment and the light intensity level of the light effect for the functional general lighting device(s) at the second moment is below a predetermined threshold.

In other words, if the light emitting surface is represented by <NUM>, the lighting emitting inner rim is represented by <NUM>, and the functional general lighting device is represented by <NUM>, the following conditions are preferably complied with at the first moment to increase the sensation of spaciousness: <MAT> <MAT> <MAT>.

Preferably, the following condition is complied with at the second moment to increase the sensation of spaciousness: CT1 > CT2 > CT3. Preferably, at the first moment L1>L2>L3 and at the second moment L1>L3-L2.

Alternatively, on an average sunny day, the following conditions may be complied with:.

Alternatively, on a cloudy or foggy day, the following conditions may be complied with: first moment: CT1 ~ CT <NUM> ~ CT3 with L1 > L3 > L2 (supplemental lighting is typically needed to yield a minimum light level at a user's desk).

Alternatively, on an extremely sunny day, the following conditions may be complied with: first moment: CT1 > <NUM>, CT3 < <NUM> and CT2> <NUM>.

If the controller <NUM> is able to perform a third function, the processor <NUM> is configured to receive, via the receiver <NUM>, light sensor data from light sensor <NUM> and determine a visibility threshold based on the light sensor data. The light sensor data is indicative of an ambient light level. The processor <NUM> is further configured to determine the plurality of light effects to be rendered by the peripheral lighting device <NUM> and determine whether light intensity levels of the plurality of light effects exceed the visibility threshold. The light intensity levels comprise at least one light intensity level of the at least one light effect.

The processor <NUM> is configured to increase the at least one light intensity level above the visibility threshold, to harmonize the at least one light intensity level with the ambient light level, upon determining that the at least one light intensity level does not exceed the visibility threshold, and control, via the transmitter <NUM>, the peripheral lighting device <NUM> to render the plurality of light effects. The peripheral lighting device <NUM> is controlled to render the at least one light effect with the increased at least one light intensity level.

The processor <NUM> is configured to do the same with light sensor <NUM> and peripheral lighting device <NUM> and with light sensor <NUM> and peripheral lighting device <NUM>. Additionally, light intensity levels of other lighting devices than the peripheral lighting devices may be adjusted based on light sensor data received from one of light sensors <NUM>-<NUM>. In the embodiment of <FIG>, the plurality of light effects is specified in a dynamic light scene.

One or more of the light sensors <NUM>-<NUM> may be a multispectral light sensor. In this case, the light sensor data received from this light sensor is spectral light sensor data and the processor <NUM> is configured to determine wavelengths of the plurality of light effects and determine whether the light intensity levels of the plurality of dynamic light effects exceed the visibility threshold based on the wavelengths. In this case, the light sensor data is further indicative of an ambient color and the processor <NUM> may then be configured to adjust a color value of the at least one light effect to harmonize the color value with the ambient color.

If the controller <NUM> is able to perform a fourth function, the processor <NUM> is configured to determine, from a dynamic light scene, a plurality of light effects to be rendered by one or more of a plurality of lighting devices, control, via the transmitter <NUM>, the one or more lighting devices to render the plurality of light effects. The plurality of light effects corresponds to a first moment in the dynamic light scene. The dynamic light scene specifies a temporal sequence of light effects for each of the plurality of lighting devices. The plurality of lighting devices comprises lighting devices <NUM>-<NUM>,<NUM>,<NUM>, and <NUM> or a subset thereof.

The processor <NUM> is further configured to receive a user input signal via the receiver <NUM>, determine a second moment in the dynamic light scene based on the user input signal, determine a transition from the first moment to the second moment, determine, from the dynamic light scene, a plurality of further light effects to be rendered by the one or more lighting devices, and control, via the transmitter <NUM>, the one or more lighting devices to render the plurality of further light effects after the transition. The plurality of further light effects corresponds to the second moment in the dynamic light scene.

The transition is faster than a normal transition from the first moment to the second moment, as specified in the dynamic light scene. The transition is immediate for at least a first subset of the one or more lighting devices and gradual for at least a second subset of the one or more lighting devices. The user input signal is indicative of a time difference between the first moment and the second moment and/or indicative of a desire to go forward in time in the dynamic light scene or indicative of a desire to go backward in time in the dynamic light scene.

As a first example, the dynamic light scene represents a daylight scene and the first moment and the second moment correspond to different times of a day. As a second example, the dynamic light scene represents a firelight scene and the first moment and the second moment correspond to different scales of a fire. As a third example, the dynamic light scene represents a forest scene and the first moment and the second moment correspond to different tree and/or leaf densities.

In the example of <FIG>, the user input signal is received from a mobile device <NUM>. Both the controller <NUM> and the mobile device <NUM> are connected to a wireless LAN access point <NUM>, e.g. via Wi-Fi. The mobile device <NUM> may run an app for controlling the lighting devices of the lighting system <NUM> or a subset thereof, for example. The wireless LAN access point <NUM> is also connected to Internet <NUM>. An Internet server <NUM> is also connected to the Internet. The Internet server <NUM> may store dynamic light scenes, for example.

In an alternative embodiment, the user input signal is received via a control device that comprises a one-dimensional control element, e.g. a (continuous) rotatable control element. The control device may be comprised in the controller <NUM> or may be external to the controller <NUM>. The control device may comprise a display and may be configured to display a representation of the first moment and/or the second moment in the dynamic light scene on the display.

It is beneficial to display dynamic visual feedforward and feedback on the control display or on another screen within the room (e.g. smart phone, smart TV or video projector) that can render the current scene in high fidelity, e.g. passing clouds, moving tree canopy, or reflections on water, along with the current value of the dominant parameter controlled by the one-dimensional control element. This dynamic visualization of what is currently playing (e.g. slowly passing clouds) may be adapted dynamically in real-time when the one-dimensional control element is used to change the dominant parameter (e.g. change in cloudiness as clouds continue to pass by at a given time of the day), giving further feedforward/feedback to the user in addition to changes in the lighting system.

It is effective, intuitive and useful to allow humans to control only, and only one light scene parameter for the current scene, preferably the most dominant parameter indicative for the light scene (to be) selected. For a pre-stored dynamic light scene, allowing a user to change individual settings of the dynamic light scene is less beneficial. However, even if the dynamic light scene is created in real-time by dynamic lighting program and it might be possible to allow a user to change higher-level parameters of the program, it is very intuitive to allow the user to be able to change the moment in a dynamic light scene, e.g. in a dynamic light scene that mimics the light conditions outside or in a firelight scene. The moment in the dynamic light scene may correspond to a time of day, for example, but this is not required.

If the dynamic light scene is created in real-time by dynamic lighting program, there may be further (higher-level) parameters that a user is allowed to change, e.g. the weather condition in a daylight mimicking light scene or a light scene scape. In the embodiment of <FIG>, the processor <NUM> is configured to determine one or more values of one or more such further parameters based on the user input signal, adapt at least one of the plurality of further light effects to be rendered by the one or more lighting devices based on the one or more values and control the one or more lighting devices to render the adapted at least one further light effect after the transition.

If a dynamic lighting program renders a fire scene with outdoor mimicking light conditions as backdrop, the user may be able to change the time of day by changing the moment in the dynamic light scene, but may additionally be able to change one or more higher-level parameters relating to the fire. These one or more higher-level parameters may be nested parameters, i.e. a value of a higher-level parameter may correspond to values of multiple different lower-level parameters. Changes these further parameters may also be immediate or gradual.

For example, the user may be able to change the amount of wood on the fire and the transition may be gradual. This is beneficial, because when a calm bonfire is fed by adding more wood to a real fire, it also takes some time before the colors of the fire get richer, the level of motion intensifies, the height of the flames rises as well as the flame density and frequency of change. Thus, a single action of adding wood induces changes in the lower-level parameters (amount and rate of flame-able ingredients escaping at velocity v and burning at height x, at color point y, in and ambient of temperature T and a wind velocity w, etc. etc.), and may affect the rendering on multiple lighting devices.

In the embodiment of the controller <NUM> shown in <FIG>, the controller <NUM> comprises one processor <NUM>. In an alternative embodiment, the controller <NUM> comprises multiple processors. The processor <NUM> of the controller <NUM> may be a general-purpose processor, e.g. ARM-based, or an application-specific processor. The processor <NUM> of the controller <NUM> may run a Unix-based operating system for example. The memory <NUM> may comprise one or more memory units. The memory <NUM> may comprise one or more hard disks and/or solid-state memory, for example.

The receiver <NUM> and the transmitter <NUM> may use one or more wired or wireless communication technologies such as Zigbee or Bluetooth to communicate with the sensor devices <NUM>-<NUM> and the lighting devices <NUM>-<NUM>, <NUM>, <NUM> and <NUM> and Ethernet or Wi-Fi to communicate with the wireless LAN access point <NUM>, for example. In an alternative embodiment, multiple receivers and/or multiple transmitters are used instead of a single receiver and a single transmitter. In the embodiment shown in <FIG>, a separate receiver and a separate transmitter are used. In an alternative embodiment, the receiver <NUM> and the transmitter <NUM> are combined into a transceiver. The lighting devices <NUM>-<NUM>, <NUM>, <NUM>, <NUM> each comprise a plurality of LEDs. The LEDs may be direct emitting or phosphor converted LEDs.

The controller <NUM> may comprise other components typical for a controller such as a power connector. The invention may be implemented using a computer program running on one or more processors. In the embodiment of <FIG>, the system of the invention is a controller. In an alternative embodiment, the system of the invention is a different device, e.g. a lighting device. In the embodiment of <FIG>, the system of the invention comprises a single device. In an alternative embodiment, the system of the invention comprises a plurality of devices.

An example, not covered by the scope of the claims, of the method of controlling a lighting arrangement comprising an artificial skylight and a functional general lighting device for providing horizontal light is shown in <FIG>. The functional general lighting device comprises a horizontal luminous surface. The functional general lighting device is positioned in parallel and adjacent to the artificial skylight. A spacing between the functional general lighting device and the artificial skylight does not exceed the width of the artificial skylight.

A step <NUM> comprises determining a dynamic light scene. The dynamic light scene specifies a temporal sequence of light effects for each of a plurality of lighting devices, including the artificial skylight and the functional general lighting device. In step <NUM>, the dynamic light scene may be partly or entirely obtained from a memory and/or or may be partly or entirely created, e.g. by a dynamic lighting program. Parameters for the dynamic light scene may specify that the artificial skylight should render blue and/or cyan light and the functional general lighting device should render light with a color temperature between <NUM> Kelvin and <NUM> Kelvin, for example.

A step <NUM> comprising determining light effects corresponding to a current moment in the sequences of light effects. A different light effect is determined for each of the plurality of lighting devices. Each light effect comprises a light intensity level and a color. If the lighting device only renders white light, the color may be expressed as color temperature, for example.

In the embodiment of <FIG> a step <NUM> is performed after step <NUM>. Step <NUM> comprises harmonizing the light level for the functional general lighting device to the light level specified for the artificial skylight. Steps <NUM> and <NUM> comprise controlling the artificial skylight and the functional general lighting device, respectively, to render the different light effects determined in step <NUM>. Step <NUM> is repeated after steps <NUM> and <NUM> have been performed, after which the method proceeds as shown in <FIG>.

In a variant on the embodiment of <FIG>, the artificial skylight comprises a light emitting surface and a light emitting inner rim surrounding the light emitting surface. The light emitting inner rim is perpendicular to the light emitting surface. In this variant, step <NUM> comprises controlling the artificial skylight to render a shadow effect along at least part of the inner rim.

Alternatively, the light emitting inner rim may comprise a (static) hard mask for creating a static shadow, e.g. at the front or at the back side of a backlit light diffuser. In the latter case, the hard mask is located between the backlight and the light diffuser, preferably arranged in close proximity (typically the closer the better) to the backside of the light diffuser, but not optically touching. The mask may be an integral part of the frame onto which the light diffuser is attached (typically by clamping), a separate part attached to the frame, or a "spring"load part pushed against the back side of the light diffuser, for example.

Alternatively, the shape of the light-engine and/or the mixing box may be reshaped from rectangular to a shape having one slanted side to create a shadow effect. The light effects for the light emitting surface and the light emitting rim may specified separately in the dynamic light sequence.

An example, not covered by the scope of the claims, of the method of controlling an artificial skylight to render light effects is shown in <FIG>. The artificial skylight comprises a light emitting surface and a light emitting inner rim surrounding the light emitting surface. The light emitting inner rim is perpendicular to the light emitting surface.

A step <NUM> comprises determining a weather condition, e.g. normal sunny day, extremely sunny day, cloudy day, or foggy day. A step <NUM> comprises determining a dynamic light scene based on the weather condition determined in step <NUM>. The dynamic light scene specifies a temporal sequence of light effects for each of a plurality of lighting devices. The plurality of lighting devices comprises the light emitting surface, the light emitting inner rim and a functional general lighting device for providing horizontal light. The functional general lighting device comprises a horizontal luminous surface. In an alternative embodiment, step <NUM> is omitted and the dynamic light scene is not determined based on a weather condition.

In the embodiment of <FIG>, step <NUM> comprises sub steps <NUM> and <NUM>. Step <NUM> comprises determining the light intensity levels of the light effects and step <NUM> comprises determining the color temperatures of the light effects. In the dynamic light scene, the light intensity level of the light effect for the light emitting surface at a first moment in the dynamic light scene is higher than the light intensity level of the light effect for the light emitting surface at a second moment in the dynamic light scene. The intensity level of the light effect for the light emitting inner rim at the first moment is higher than the light intensity level of the light effect for the light emitting inner rim at the second moment. The light intensity level of the light effect for the functional general lighting device at the first moment is higher than the light intensity level of the light effect for the functional general lighting device at the second moment.

Furthermore, in the dynamic light scene, the color temperature of the light effect for the light emitting surface at the first moment is higher than the color temperature of the light effect for the light emitting surface at the second moment. The color temperature of the light effect for the light emitting inner rim at the first moment is higher than the color temperature of the light effect for the light emitting inner rim at the second moment. The color temperature of the light effect for the functional general lighting device at the first moment is higher than the color temperature of the light effect for the functional general lighting device at the second moment.

Steps <NUM> and <NUM> are performed after step <NUM>. Step <NUM> comprising determining a light effect for the artificial skylight which corresponds to a current moment in the corresponding sequence of light effects. Step <NUM> comprises determining a light effect for the functional general lighting device which corresponds to the current moment in the corresponding sequence of light effects.

Steps <NUM> and <NUM> comprise controlling the artificial skylight and the functional general lighting device, respectively, to render the light effects determined from the dynamic light scene in steps <NUM> and <NUM>, respectively. Step <NUM> and <NUM> are repeated after steps <NUM> and <NUM> have been performed, after which the method proceeds as shown in <FIG>.

A first example, not covered by the scope of the claims, of the method of adjusting at least one light effect of a plurality of light effects to be rendered by a lighting device based on an ambient light level is shown in <FIG>. A step <NUM> comprises receiving light sensor data from a light sensor. The light sensor data is indicative of an ambient light level. Sampling of the ambient light level may be done (semi) continuous or intermittent with the electronic switching of the artificial light (for example at start-up/in between PWM cycles, or differential (as the system drive waveforms, thus, the spectral modulation of the overall light is known), for example.

A step <NUM> comprises determining a visibility threshold based on the light sensor data. A step <NUM> comprises determining the plurality of light effects to be rendered by the lighting device. A step <NUM> comprises determining whether light intensity levels of the plurality of light effects exceed the visibility threshold. The light intensity levels comprise at least one light intensity level of the at least one light effect.

A step <NUM> comprises increasing the at least one light intensity level above the visibility threshold, to harmonize the at least one light intensity level with the ambient light level, upon determining that the at least one light intensity level does not exceed the visibility threshold. A step <NUM> comprises controlling the lighting device to render the plurality of light effects. The lighting device is controlled to render the at least one light effect with the increased at least one light intensity level.

The method is typically used to control a plurality of lighting devices in a lighting system. Preferably, different pixelated lighting devices are controlled to work together as one system. The plurality of lighting device may comprise a realistic feeling, artificial skylight providing a view to the sky, an accent (peripheral) light providing biological and emotional (patterns, colors and rhythm) light, and a general lighting device providing functional light.

In this manner, a natural lighting system may be provided that has system behavior that improves upon the behavior of conventional and static lighting systems in that the natural lighting system automatically harmonizes its behavior towards the ambient light conditions within the (office) space relative to its own system capabilities, with the aim to sustain an immersive and natural feeling light experience under a wide variety of ambient light conditions, with the natural feeling being inspired upon the constant cycles and variations of nature, whilst simultaneously at least sustaining a minimum light level at the working surface and vertical surfaces of a space (i.e. walls) where applicable, consistent with a direct view at a natural feeling artificial skylight and vice versa.

A second example, not covered by the scope of the claims, of the method of adjusting at least one light effect of a plurality of light effects to be rendered by a lighting device based on an ambient light level is shown in <FIG>. Step <NUM> comprises receiving light sensor data from a light sensor. The light sensor data is indicative of an ambient light level. Step <NUM> comprises determining a visibility threshold based on the light sensor data.

Next, a step <NUM> comprises determining a difference between a maximum light level which can be rendered by the lighting device and the ambient light level. Step <NUM> comprises determining the plurality of light effects to be rendered by the lighting device. In the embodiment of <FIG>, step <NUM> is implemented by a step <NUM>. Step <NUM> comprises determining the plurality of light effects to be rendered by the lighting device based on the difference determined in step <NUM>. If the difference is large, a dynamic light sequence may be selected that is less like the conditions (e.g. time of day, season, weather conditions) outside. If the difference is not large, a dynamic light sequence may be selected that is more like the conditions outside.

In certain instances, it may be useful to choose the content/dynamic light scene such that at least part of the content rises above the visibility threshold or the content playing such that it feels as a natural extension of outdoors, indoor. At yet another time of the day, such as during the golden hour, the color of the ambient (incident day) light may shift towards the more reddish colors. This may be possible if the light sensor data is further indicative of an ambient color.

Step <NUM> comprises determining whether light intensity levels of the plurality of light effects exceed the visibility threshold. The light intensity levels comprise at least one light intensity level of the at least one light effect. Light effects with light intensity levels that exceed the visibility threshold are selected in step <NUM>. A step <NUM> is performed after step <NUM>. Step <NUM> comprises increasing these light intensity levels to harmonize them with the ambient light level.

For light effects with light intensity levels that do not exceed the visibility threshold, a step <NUM> is performed. Step <NUM> comprises determining whether one or more of these light intensity levels can be increased above the visibility threshold. Light effects with these intensity levels are selected in step <NUM>. The remaining light effects, if any, are selected in step <NUM> and omitted from the light effect rendering in step <NUM>.

Step <NUM> is performed after step <NUM>. In the embodiment of <FIG>, step <NUM> is implemented by a step <NUM>. Step <NUM> comprises increasing the light intensity levels selected in step <NUM> above the visibility threshold, proportional to the ambient light level. Step <NUM> comprises controlling the lighting device to render the light effects selected in steps <NUM> and <NUM> with the light intensity levels as determined in steps <NUM> and <NUM>.

Dynamic lighting systems such as NatureConnect systems preferably apply different strategies under different ambient light conditions, with the system strategy automatically chosen depending upon, for example, the local light conditions (artificial light and/or daylight), season, weather, space utilization, content already playing, and the use of blinds. As a result, the same system in the same space may be capable of overperforming the ambient light conditions for one particular time of the day, whereas on different ambient light conditions for another part of the same day, the same system may be underperforming.

The aim of the system is to provide an optimal, natural feeling and immersive light-experience at all times, but this is typically not achieved by (exactly) copying (the light levels and/or dynamics) of the outdoors. Instead, the dynamic lighting system harmonizes the constant cycles and variation of nature in a natural feeling manner across a space, e.g. office space, by increasing light intensity levels above the visibility threshold where desirable.

Graph <NUM> of <FIG> shows an example of a sequence of light effects <NUM> being rendered by an overperforming system, i.e. all the light effects exceed the visibility threshold <NUM>. Graph <NUM> of <FIG> shows an example of the sequence of light effects <NUM> being rendered by a partially underperforming system, i.e. some of the light effects do not exceed the visibility threshold <NUM>. To make sure that all of the light effects are visible, the light intensity levels of the light effects with a light intensity level below the visibility threshold are increased above the visibility threshold, resulting in light effects <NUM>, as shown in graph <NUM> of <FIG>.

In the example of <FIG>, the light intensity levels of the light effects with a light intensity level above the visibility threshold are not increased. However, it is sometimes beneficial to increase the light intensity levels of the light effects with a light intensity level above the visibility threshold. This is beneficial in certain cases, e.g. to allow a system to adjust and harmonize the sparkle level of a dapple effect up to the upper system limit to sustain the dapple effect.

The light intensity levels of the non-sparkling light effects are preferably just above the visibility threshold. To increase a sparkling effect, they may be lowered to just above the visibility threshold in an overperforming system in which the light intensity levels of the sparkling light effects cannot be increased due to upper system limit.

If the ambient light level would rise even further, the dapple effect may drown as a whole, i.e. be flooded by the natural (day) light, with the system thereby becoming underperforming. In such cases, it may be more effective and useful to either drop the dapple effect as a whole or to turn a large part of the dapple effect off, in that only the sparkling component of the content may be dimmed or switched off.

Thus, when the natural light is underperforming, the ambient light conditions offer an opportunity to the artificial system to more easily change and/or provide a semantic meaning of the content played, with the option to either match or to deviate from the natural (day) light (scenes), whereas for overperforming natural light (and open blinds), it is more efficient and natural to go along with the flow, in matching and/or extending the outdoor feel indoors.

The light sensor data is used to harmonize, and if necessary throttle, at least part of the first rhythm towards the ambient light conditions by raising part of the first rhythm above a given system threshold when the system is capable of overperforming, or dropping or partially dropping part of the natural content playing when underperforming. This may be done in different proportions across a day, depending upon the content played as well as the sensed ambient light conditions indoor. This allows an immersive and natural feeling light experience to be sustained at least up to a first performance threshold of the system.

For an underperforming system, the light effects of at least a first portion of the content played, drowning in the ambient light, may be dropped or switched off, and if the artificial content would be completely drowned, the system may automatically decide to play alternative content for which at least a first portion of the content is harmonized to the sensed ambient light conditions (e.g. light level and/or light color).

A third example, not covered by the scope of the claims, of the method of adjusting at least one light effect based on an ambient light level is shown in <FIG>. Step <NUM> comprises receiving light sensor data from one or more light sensors. In the embodiment of <FIG>, the one or more light sensors are multispectral light sensors and the light sensor data received from the one or more light sensors is spectral light sensor data. The light sensor data is indicative of an ambient light level and is further indicative of an ambient color. A light sensor may be associated with a certain space and/or certain lighting devices. The light sensor is able to distinguish between at least two wavelength regions and may be cyan or blue "centered", for example.

Multispectral light sensors are preferred over conventional light sensors having no spectral selectivity. The spectral differences between sunny and overcast days manifest themselves predominantly in the wavelength range above <NUM>. Below <NUM>, in the blue, changes in the weather are predominantly reflected by the light intensity, whereas during the course of a sunny day, intensity variations across the whole daylight spectrum dominate. Thus, the preference for a cyan comprising sensor is due to cyan being the tipping point for the dependency of spectral power on the weather, i.e. the spectral power of light with a wavelength longer than cyan is more dependent on the weather than the spectral power of light with a wavelength shorter than cyan.

Multispectral light sensors are also deployed in mobile phones, digital cameras and recorders. Spectral selective data allows for the mathematic extraction of the overall light intensity, white balance, CCT, as well as the (relative) spectral contributions of the whole system to the overall light conditions of a given (office) space for at least two or more spectrally different wavelengths (regions), for example by sampling Red and Blue, or Red, Green and Blue or Cyan and Red, or Blue, Cyan and Red, whereas with differential sensing (using two identical sensors) the electronic modulation of the artificial light on top of (near) static ambient (day)light can be easily detected as well.

Pixelated lighting devices can benefit from spectral sensing in that besides for dimming or boosting, spectral selective sensing will also allow for a much more natural feeling representation of the content played. Moreover, the "white" balance of a space can be tracked and corrected for, or be matched (between spaces), during the course of the day. To detect and weigh the (relative (spectral) changes in the (local) ambient light conditions within a space, with respect to the system capabilities of the natural lighting system, at least the spectral data of at least one wavelength (region) selective (light) sensor is fed to a system controller.

Step <NUM> comprises determining one or more visibility thresholds based on the light sensor data, e.g. one visibility threshold per light sensor. Next, in step <NUM>, a first lighting device is selected from one or more lighting devices that are involved in a certain dynamic light scene. In step <NUM>, the visibility threshold relevant to the selected lighting device is selected from the one or more visibility thresholds determined in step <NUM>.

Then, step <NUM> comprises determining the plurality of light effects to be rendered by the selected lighting device from the dynamic light scene. A step <NUM> comprises determining wavelengths of the plurality of light effects determined in step <NUM> based on the light sensor data. The light sensor data comprises data of at least a first and a second wavelength region, and preferably of at least three different wavelength regions.

Step <NUM> is performed after step <NUM>. In the embodiment of <FIG>, step <NUM> is implemented by a step <NUM>. Step <NUM> comprises determining whether any of the light intensity levels of the plurality of dynamic light effects exceed the visibility threshold based on the wavelengths determined in step <NUM>. For example, a green light effect and a yellow light effect may have the same intensity levels, but only the green light effect may be visible under the current ambient lighting conditions.

Next, it is determined in a step <NUM> whether the lighting device is located in a transition zone, e.g. based on the visibility threshold selected in step <NUM>. If the visibility exceeds a first level and stays below a second level, the lighting device is considered to be located in a transition zone and a step <NUM> is performed next. Otherwise, a step <NUM> is performed. Steps <NUM> and <NUM> implement step <NUM>.

Steps <NUM> and <NUM> comprises increasing the light intensity levels that do not exceed the visibility threshold above the visibility threshold, to harmonize them with the ambient light level. Steps <NUM> and <NUM> also comprise adjusting a color value of at least one of the light effects determined in step <NUM> to harmonize the color value with the ambient color.

For example, one or more of the color components of the dapple effect may be shifted to enhance the immersive light experience in a natural feeling manner. Similarly, the artificial skylight, functional and peripheral/accent lights may also be adjusted, with a part or the whole of the content being shifted to match the spectral distribution of the ambient light, such that a natural-feeling, immersive light-experience is sustained across the space.

In step <NUM>, these light effects are also harmonized with further light effects rendered by a further lighting device, e.g. which is located in a zone adjacent to the transition zone that is closer to a window. Light intensity levels that already exceed the visibility threshold may also be adjusted to harmonize them with the ambient light level and/or to harmonize these light effects with the further light effects.

Step <NUM> comprises controlling the lighting device to render the plurality of light effects determined in step <NUM> and adjusted in step <NUM>. Next, a step <NUM> comprises checking whether there are any further lighting devices involved in the dynamic light scene and if so, selecting the next lighting device and repeating steps <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> for this next lighting device.

Distributed controllers may render different dynamic light scenes and/or different parts of a dynamic light scene. Each of these distributed controllers may perform the method of <FIG>, for example. In this case, the light sensor may not only be used to determine the level of the real natural light outside, but also to determine the light intensity levels of dynamic light effects rendered by further lighting devices in adjacent zones.

Alternatively, a dynamic light scene may be rendered on lighting devices located in a larger space by using a central controller, e.g. using the method described in <FIG>. Each lighting device may be assigned to a zone. Each zone typically comprises one or more light sensors. For example, an artificial transition zone may be created that naturally links the outdoor to one or more different indoor (light) scenes. Thus, artificial transition zones can act as a natural feeling "buffer zone" between either different artificial indoor scenes and/or different artificial indoor and real outdoor scenes. Further away from the windows, an "isle" zone might be created having a different "climate, weather, scenery" than outdoors/near the window.

Which zones are created and how large the zones are typically depends on the ambient light conditions, which depend on the weather conditions. <FIG> depict three space harmonization options for different ambient light conditions. <FIG> depicts sunny weather conditions. In <FIG>, the zone <NUM> nearest to the window <NUM> is made a "go along" zone, because of the unhindered light beams of the sun, represented by reference numeral <NUM>. The go-along zone <NUM> comprises the peripheral lighting device <NUM> and light sensor <NUM> of <FIG>.

The zone <NUM> is farthest from the window <NUM> and therefore made an "isle" zone. An isle zone offers a complete freedom of scenery. Isle zones may be naturally linked with the artificial light scenes running in the inner building spaces and corridors. The isle zone <NUM> comprises the lighting arrangement <NUM>, the peripheral lighting device <NUM>, and the light sensor <NUM> of <FIG>. The zone <NUM> between go-along zone <NUM> and isle zone <NUM> is made a transition zone. Transition zone <NUM> comprises the functional general lighting device <NUM>, the lighting arrangement <NUM>, the peripheral lighting device <NUM>, and the light sensor <NUM> of <FIG>.

<FIG> depicts overcast weather conditions, represented by sun <NUM> and clouds <NUM>. Due to the lower ambient light level, only a transition zone <NUM> and an isle zone <NUM> are made. The go-along zone <NUM> of <FIG> is now the transition zone <NUM> and the transition zone <NUM> and the isle zone <NUM> of <FIG> are now the isle zone <NUM>.

<FIG> depicts cloudy weather conditions, represented by clouds <NUM>. Due to the even lower ambient light level, only an isle zone <NUM> is made. The go-along zone <NUM>, the transition zone <NUM> and the isle zone <NUM> of <FIG> are now the isle zone <NUM>.

Besides adapting to outdoor changes (in the (spectral) ambient light conditions), adaption of the indoor rhythms and content playing may also be triggered by other indoor conditions, such as for example furniture or walls of given color(s) and/or reflectivity or vice versa, or the absence thereof. Further, differences in space utilization and/or occupancy may affect the local rhythm, patterns and colors (i.e. content played). In other instances, e.g. in the case of a flickering or blinking light(s) of other device(s) or broken light also present in the same space as the natural lighting system, the content playing may be harmonized towards such lights.

In a situation in which the outdoor light brightens up and the blinds are (still) open, although there is a surplus of ambient light, a device such as an artificial skylight should preferably not be dimmed. Instead, the overall brightness of the sky and (illusion of the) sun should preferably also increase, but in proper relation to the functional light provided by the system. Moreover, to sustain a natural and immersive light experience across the space, the functional light level farther away from the windows may even be boosted (well above the minimum threshold) to improve upon the overall experience. In addition, depending upon the position of the dapple effect(s) in the space, the level of "sparkle" of the dapple effect may automatically be adapted as well. And, in order not to distract the office workers, such changes and adaptations should preferably be smooth and gradual.

The natural lighting system may adapt to other (dis)functional lighting devices within the same space not being part of the natural lighting system, whilst harmonizing the content playing to include the light(s) of the other (dis)functional lights, such that the whole the lighting devices appears to act as one system.

A first embodiment of the method of controlling a plurality of lighting devices to provide an illumination of an environment according to a dynamic light scene is shown in <FIG>. A step <NUM> comprises determining a dynamic light scene. The dynamic light scene specifies a temporal sequence of light effects for each of the plurality of lighting devices. A step <NUM> comprises determining a moment in the sequence at which the rendering should start, e.g. the start of the sequence, to be used in a step <NUM>.

Step <NUM> comprises determining, from the dynamic light scene, a plurality of light effects to be rendered by one or more of the lighting devices. In the first iteration of step <NUM>, the plurality of light effects determined in step <NUM> corresponds the moment determined in step <NUM>, e.g. to the start of the dynamic light scene. A step <NUM> comprises controlling the one or more lighting devices to render the plurality of light effects determined in step <NUM>.

A step <NUM> comprises checking whether a user input signal has been received in a step <NUM>. In the embodiment of <FIG>, step <NUM> is triggered by the user input signal being received or by a certain time having elapsed, i.e. a next moment being reached. This next moment succeeds the moment to which the light effects determined in step <NUM> correspond. This next moment may be the first moment at which one of the light effects next in the sequence(s) is different, for example. If a user input signal has been received, step <NUM> is performed next. If not, a step <NUM> is performed next. Step <NUM> comprises determining that the next moment should be used in the next iteration of step <NUM>.

Step <NUM> comprises determining a second moment in the dynamic light scene based on the user input signal. This second moment is different from the moment to which the light effects determined in step <NUM> correspond, which is referred to as "first moment", and different from the next moment. The user input signal may be indicative of a time difference between the first moment and the second moment. For example, the amount of rotation of a rotary button may indicate this time difference. If the user is only able to go forward in time, the second moment may be determined based only on this time difference.

If the user input signal is also indicative of a desire to go forward in time in the dynamic light scene, e.g. when the rotary button is rotated to the right, or indicative of a desire to go backward in time in the dynamic light scene, e.g. when the rotary button is rotated to the right, the second moment may be determined based on the time difference in combination with the forward/backward indication. A step <NUM> comprises determining a transition from the first moment to the second moment. The transition is faster than a normal transition from the first moment to the second moment, as specified in the dynamic light scene.

This transition is immediate for a first subset of the one or more lighting devices and gradual for a second subset of the one or more lighting devices. If the transition is immediate for each lighting device, step <NUM> is repeated after step <NUM>. In the next iteration of step <NUM>, a plurality of further light effects to be rendered by the one or more lighting devices is determined. This plurality of further light effects corresponds to the second moment in the dynamic light scene. In the next iteration of step <NUM>, the one or more lighting devices are controlled to render this plurality of further light effects. Then, the method proceeds as shown in <FIG>.

If the transition is gradual for at least one of one or more lighting devices, a step <NUM> is performed after step <NUM>. Step <NUM> comprises determining one or more intermediate light effects to be rendered by the second subset of lighting devices. Each of the one or more intermediate light effects corresponds to a moment between the first moment and the second moment in the dynamic light scene. Step <NUM> comprises controlling the second subset of lighting devices to render the one or more intermediate light effects during the transition. Step <NUM> is repeated after step <NUM> in the same way as when it is performed directly after step <NUM>.

A second embodiment of the method of controlling a plurality of lighting devices to provide an illumination of an environment according to a dynamic light scene is shown in <FIG> is an extension of the embodiment of <FIG>. In the embodiment of <FIG>, a step <NUM> is additionally performed after step <NUM>. A step <NUM> comprises determining a moment in the sequence at which the rendering should start to be used in a step <NUM>.

Step <NUM> comprises determining, from the dynamic light scene, a first plurality of light effects to be rendered by at least one other lighting device of the plurality of lighting devices. In the first iteration of step <NUM>, the first plurality of light effects determined in step <NUM> corresponds the moment determined in step <NUM>. A step <NUM> comprises controlling the at least one other lighting device to render the first plurality of light effects determined in step <NUM>.

The moment determined in step <NUM> is different than the moment determined in step <NUM>. If the moment determined in step <NUM> is the start of the sequence, the moment determined in step <NUM> is the start of the sequence plus a time difference. This ensures that the light effects rendered in step <NUM> are delayed compared to the light effects rendered in step <NUM>.

A step <NUM> comprises determining the next moment that should be used in the next iteration of step <NUM>. This next moment succeeds the moment to which the light effects determined in step <NUM> correspond. This next moment may be the first moment (after the current moment) at which one of the light effects next in the sequence(s) is different, for example.

In the next iteration of step <NUM>, a second plurality of light effects to be rendered by the at least one lighting device is determined. This second plurality of light effects corresponds to the next moment in the dynamic light scene. In the next iteration of step <NUM>, the at least one lighting device is controlled to render this second plurality of light effects. Then, the method proceeds as shown in <FIG>.

Since the moment used in step <NUM> does not depend on the user input signal received in step <NUM>, the user input signal affects the time difference between the moments used in simultaneous iterations of steps <NUM> and <NUM>, i.e. affects the delay of the light effects rendered in step <NUM> compared to the light effects rendered in step <NUM>. For example, the user may be able to increase and decrease the dynamics of a dapple effect trail, following the initial dapple effect, in this way.

A third embodiment of the method of controlling a plurality of lighting devices to provide an illumination of an environment according to a dynamic light scene is shown in <FIG> is an extension of the embodiment of <FIG>. In the embodiment of <FIG>, like in the embodiment of <FIG>, steps <NUM>, <NUM> and <NUM> are additionally performed after step <NUM>. In contrast to the embodiment of <FIG>, the moment used in next iterations of step <NUM> depends on the user input signal received in step <NUM>.

If it is determined in step <NUM> that a user input signal has been received, steps <NUM> and <NUM> are performed next. If not, previously described steps <NUM> and <NUM> are performed next. Step <NUM> comprises determining a fourth moment in the dynamic light scene based on the user input signal. This fourth moment is different from the moment to which the light effects determined in step <NUM> correspond, which is referred to as "third moment", and different from the next moment, which would have been determined if step <NUM> were to be performed. The fourth moment is also different than the second moment, but a time difference between the first moment and the third moment is equal to a time difference between the second moment and the fourth moment.

Thus, while the second and fourth moment are determined based on the user input signal, the user input signal does not affect the time difference between the moments used in simultaneous iterations of steps <NUM> and <NUM>, i.e. does not affect the delay of the light effects rendered in step <NUM> compared to the light effects rendered in step <NUM>.

A step <NUM> comprises determining a transition from the first moment to the second moment. The transition is faster than a normal transition from the first moment to the second moment, as specified in the dynamic light scene. If the transition is immediate for each lighting device, step <NUM> is repeated next. In the next iteration of step <NUM>, a second plurality of further light effects to be rendered by the at least one other lighting device is determined. This second plurality of further light effects corresponds to the fourth moment in the dynamic light scene. In the next iteration of step <NUM>, the at least one other lighting device is controlled to render this second plurality of further light effects. Then, the method proceeds as shown in <FIG>.

If the transition is gradual for one or more of the at least one lighting device, a step <NUM> is performed after step <NUM>. Step <NUM> comprises determining one or more intermediate light effects to be rendered by these one or more lighting devices. Each of the one or more intermediate light effects corresponds to a moment between the third moment and the fourth moment in the dynamic light scene. Step <NUM> comprises controlling the one or more lighting devices to render the one or more intermediate light effects during the transition. Step <NUM> is repeated after step <NUM> in the same way as when it is performed directly after step <NUM>.

<FIG> shows an example of a dynamic light scene comprising color (c) settings <NUM> and lighting intensity (li) settings <NUM>. At a first moment <NUM>, a user input signal is received. The user input signal is indicative of a desire to go forward in time to a second moment <NUM>.

<FIG> show examples of the dynamic light scene of <FIG> being partially rendered. <FIG> shows an immediate transition. The light settings specified for the second moment <NUM> in the dynamic light scene of <FIG> are rendered directly after the light settings specified for the first moment <NUM> have been rendered. <FIG> shows a gradual transition. The duration of this gradual transition is faster than the normal transition from the first moment <NUM> to the second moment <NUM>, as specified in the dynamic light scene. The gradual transition may take a few seconds to a few minutes, for example. The transition may be linear or may have a similar shape as the function encompassing the light settings between the first moment <NUM> and the second moment <NUM>, as specified in the dynamic light scene, for example. The latter is shown in <FIG>.

The embodiments of <FIG>, <FIG>, and <FIG> to <NUM> differ from each other in multiple aspects, i.e. multiple steps have been added, omitted and/or replaced. In variations on these embodiments, only a subset of these steps is added, omitted and/or replaced. For example, the embodiments of <FIG>, <FIG>, <FIG> and <FIG> may be combined.

A third alternative embodiment of the lighting arrangement <NUM> of <FIG> is shown in <FIG>. A lighting device <NUM> comprises a lighting arrangement <NUM> and a controller <NUM>. The lighting arrangement <NUM> comprises artificial skylights <NUM>-<NUM> and functional general lighting devices <NUM> and <NUM> for providing horizontal light. The functional general lighting devices <NUM> and <NUM> each comprise a horizontal luminous surface. The functional general lighting devices <NUM> and <NUM> are positioned in parallel and adjacent to the artificial skylights <NUM>-<NUM>.

A spacing between the functional general lighting devices <NUM> and <NUM> and the artificial skylights <NUM>-<NUM> does not exceed the width of the artificial skylights <NUM>-<NUM>. The lighting arrangement <NUM> further comprises artificial edge functional general lighting devices <NUM> and <NUM> for providing horizontal light. The edge functional general lighting devices <NUM> and <NUM> each comprising a horizontal luminous surface.

The controller <NUM> comprises a processor <NUM>, a transceiver <NUM> and a memory <NUM>. The controller <NUM> is configured to control the artificial skylights <NUM>-<NUM>, the functional general lighting devices <NUM> and <NUM> and the edge general lighting devices <NUM> and <NUM> to render different light effects of a dynamic light scene. The dynamic light scene specifies a temporal sequence of light effects for each of a plurality of lighting devices. The plurality of lighting devices includes the artificial skylights <NUM>-<NUM>, the functional general lighting devices <NUM> and <NUM> and the edge general lighting devices <NUM> and <NUM>.

In the embodiment of the lighting device <NUM> shown in <FIG>, the lighting device <NUM> comprises one processor <NUM>. In an alternative embodiment, the lighting device <NUM> comprises multiple processors. The processor <NUM> of the lighting device <NUM> may be an application-specific processor, for example. The transceiver <NUM> may use one or more wireless communication technologies. e.g. Zigbee, for communicating with an external controller. In an alternative embodiment, multiple receivers and/or multiple transmitters are used instead of a single transceiver.

In the embodiment shown in <FIG>, a receiver and a transmitter are combined into a transceiver, transceiver <NUM>. In an alternative embodiment, a separate receiver and a separate transmitter are used. The artificial skylights <NUM>, the functional general lighting devices <NUM> and <NUM> and the edge general lighting devices <NUM> and <NUM> each comprise a plurality of LEDs. The LEDs may be direct emitting or phosphor converted LEDs. The lighting device <NUM> may comprise other components typical for a connected lighting device such as a power connector. In an alternative embodiment, the lighting device <NUM> is not a connected lighting device. The invention may be implemented using a computer program running on one or more processors.

<FIG> depicts a block diagram illustrating an exemplary data processing system that may perform the method as described with reference to <FIG>, <FIG>, and <FIG> to <FIG>.

<FIG> shows the input device <NUM> and the output device <NUM> as being separate from the network adapter <NUM>. However, additionally or alternatively, input may be received via the network adapter <NUM> and output be transmitted via the network adapter <NUM>. For example, the data processing system <NUM> may be a cloud server. In this case, the input may be received from and the output may be transmitted to a user device that acts as a terminal.

Claim 1:
A system (<NUM>) for controlling a plurality of lighting devices (<NUM>-<NUM>,<NUM>,<NUM>,<NUM>) to provide an illumination of an environment according to a dynamic light scene, said system (<NUM>) comprising:
at least one input interface (<NUM>);
at least one output interface (<NUM>); and
at least one processor (<NUM>) configured to:
- determine said dynamic light scene,
- determine, from said dynamic light scene, a plurality of light effects to be rendered by one or more (<NUM>,<NUM>,<NUM>) of said plurality of lighting devices (<NUM>-<NUM>,<NUM>,<NUM>,<NUM>), said plurality of light effects corresponding to a first moment (<NUM>) in said dynamic light scene, said dynamic light scene specifying a temporal sequence of light effects for each of said plurality of lighting devices (<NUM>-<NUM>,<NUM>,<NUM>,<NUM>),
- control, via said at least one output interface (<NUM>), said one or more lighting devices (<NUM>,<NUM>,<NUM>) to render said plurality of light effects,
- receive a user input signal via said at least one input interface (<NUM>),
- determine a second moment (<NUM>) in said dynamic light scene based on said user input signal,
- determine a transition from said first moment (<NUM>) to said second moment (<NUM>), said transition being faster than a normal transition from said first moment (<NUM>) to said second moment (<NUM>), as specified in said dynamic light scene, wherein said transition is immediate for at least a first subset of said one or more lighting devices and wherein said transition is gradual for at least a second subset of said one or more lighting devices,
- determine one or more intermediate light effects to be rendered by said second subset of lighting devices, each of said one or more intermediate light effects corresponding to a moment between said first moment (<NUM>) and said second moment (<NUM>) in said dynamic light scene,
- determine, from said dynamic light scene, a plurality of further light effects to be rendered by said one or more lighting devices (<NUM>,<NUM>,<NUM>), said plurality of further light effects corresponding to said second moment (<NUM>) in said dynamic light scene,
- control, via said at least one output interface (<NUM>), said second subset of lighting devices to render said one or more intermediate light effects during said transition, and
- control, via said at least one output interface (<NUM>), said one or more lighting devices to render said plurality of further light effects after said transition.