Abstract: An image display system includes semiconductor light sources that output optical signals including modulated signal portions at timings different from each other, optical fiber cables that respectively transmit the optical signals, a light synthesizer that synthesizes the optical signals to output a synthesized optical signal, a light amount detector that detects an output light amount of the synthesized optical signal, a modulated signal detector that detects the modulated signal portions from the detected output light amount, an image modulator that modulates the synthesized optical signal according to an input image signal to output a modulated image light, and a light source controller that outputs drive control signals for respectively outputting the optical signals respectively including the modulated signal portions according to the image signal, and detects a failure of the optical fiber cables based on whether a modulated signal portion among the plurality of modulated signal portions is detected.

Abstract: A lighting device, such as a controllable light-emitting diode (LED) light source, may execute a self-calibration procedure to compensate for changes in an optical system of the lighting device that may have occurred after an initial factory calibration procedure. The lighting device may include an emitter, a detector that generates a detector signal in response to detected light, a memory that stores a curve defining an optical compensation value with respect to a measured forward voltage of the detector, and a control circuit configured to receive a measured value of a luminous flux of the light emitted by the emitter that may be determined in response to the detector signal and based on the optical compensation value. The control circuit may adjust the curve defining the optical compensation value in response to a difference between the measured value and an expected value of the luminous flux.

Abstract: A display device comprises a substrate, a pixel electrode on the substrate, a light emitting element on the pixel electrode, and a common electrode layer on the light emitting element, and configured to receive a common voltage, wherein the light emitting element configured to emit a first light according to a driving current having a first current density, is configured to emit a second light according to a driving current having a second current density, and is configured to emit a third light according to a driving current having a third current density.

Abstract: The lighting device may be configured to perform black body curve fading. For example, the control circuit may be configured to control the drive circuit such that the light emitted by the lighting load is adjusted (e.g., faded) along a black body curve. The control circuit may be configured to determine whether to fade from an initial color to a destination color in a Correlated Color Temperature (CCT) chromaticity space or an XY chromaticity space. The control circuit may be configured to determine whether the initial color and/or the destination color are on the black body curve. When the initial color and the destination color are determined to be on the black body curve, the control circuit may be configured to control the drive circuit such that the light emitted by the lighting device is adjusted from the initial color to the destination color along the black body curve.

Abstract: This system is directed to a batteryless, self-powered sensor comprising: a microprocessor; a first and second solar panel in electronic communications with the microprocessor; a transceiver in communication with the microprocessor; and a set of computer readable instructions included in the microprocessor adapted for creating motion data including a direction and a speed of movement of object within a first sensing area and a second sensing area, transmitted the motion data to a remote location if sufficient power is provided by the first solar panel to actuate the transceiver and a number of data points in the motion data exceeds a pre-determined number of minimal data points, associating a reduction in power delivered from the first solar panel to the microprocessor with movement and associating an increase in power delivered from the first solar panel to the microprocessor with movement.

Abstract: A light source that emits light, wherein, in coordinates in a CIE 1931 chromaticity diagram, the light has a color purity included in a region of 2 to 50 in a region surrounded by a line segment WB and a line segment WG that connect coordinates W (0.33, 0.33) indicating an achromatic color with coordinates B (0.091, 0.133) of 480 nm and coordinates G (0.373, 0.624) of 560 nm on a spectral locus, and the spectral locus, and has an area occupied by a continuous spectral wavelength in a wavelength region of 480 to 540 nm, of 15% or more relative to an area of an overall spectral wavelength of the light source at 380 to 780 nm.

Abstract: A display screen including display circuits, each display circuit including a light-emitting diode, a controllable current source powering the light-emitting diode, and a control circuit capable of supplying a pulse-width modulated signal for controlling the current source from a periodic signal. The display screen further includes first electrodes coupled to the control circuits, a circuit for supplying a selection signal successively on each first electrode, and an oscillating circuit or oscillating circuits capable of supplying the periodic signals, the periodic signals being non-synchronous with the display circuit selection signals.

Abstract: A lighting system (1) is disclosed, comprising at least one first light source (L1; 3; 4) and at least one second light source (L2; 3; 4) and at least one control unit (2). The at least one control unit (2) is configured to control the at least one first light source (L1; 3; 4) and the at least one second light source (L2; 3; 4), respectively, by changing at least the luminous flux of the emitted light, between at least a first state and a second state of the at least one first light source (L1; 3; 4) and the at least one second light source (L2; 3; 4), respectively, such that, for each of the at least one first light source (L1; 3; 4) and the at least one second light source (L2; 3; 4), the luminous flux of light emitted by the light source when in the second state is lower than the luminous flux of light emitted by the light source when in the first state.

Abstract: A method of controlling a lighting fixture based on motion detection includes: receiving a plurality of captured image frames; obtaining a plurality of resampled image frames by resampling the captured image frames according to regional characteristics of the resampled image frames; dynamically adjusting a sensitivity for motion detection according to the regional characteristics of the resampled image frames; performing motion detection on the resampled image frames according to the sensitivity; and controlling the lighting fixture according to a result of the motion detection.

Abstract: A system and corresponding method is disclosed for monitoring and conducting large-scale performance verification of a city's lighting infrastructure. In particular, the current invention combines measurements of lighting performance measurements along city roadways with regulatory requirements for the roadways. In various embodiments, the current invention then presents a three-dimensional visualization of the 5 adequacy of existing roadway lighting with respect to these regulatory requirements.

Abstract: A lighting device, such a controllable light-emitting diode (LED) light source, may execute a self calibration procedure to compensate for changes to an optical system of the lighting device that may have occurred after an initial factory calibration procedure. The lighting device may include an emitter, a detector that generates a detector signal in response to detected light, a memory that stores a curve defining an optical compensation value with respect to a measured forward voltage of the detector, and a control circuit configured to receive a measured value of a luminous flux of the light emitted by the emitter that may be determined in response to the detector signal and based the optical compensation value. The control circuit may adjust the curve defining the optical compensation value in response to a difference between the measured value and an expected value of the luminous flux.

Abstract: An LED light unit comprises an LED assembly and a light sensor to measure light emitted by the LED assembly and having a measurement range; a current source to drive the LED assembly at an LED current A control device is configured to: pre-heat the LED assembly by driving the current source to operate the LED assembly at an operating current; the LED assembly thereby illuminating the light sensor at a light level above the measurement range; interrupt operating the LED assembly during a stray light measurement time; and read an output signal of the light sensor; operate the LED assembly at a measurement current, to emit light at a measurement level; subtract the output signal of the light sensor during the stray light measurement time from the output signal of the light sensor during the light measurement time to obtain a stray light corrected light measurement signal; scale the stray light corrected light measurement signal by a scaling factor based on a ratio of the operating LED current and the measurem

Abstract: The present disclosure provides intelligent lighting control systems for adjusting a user interface on a mobile electronic device. A user input requested via the user interface to change a lighting state of one or more light emitting elements in a luminaire connected to a lighting control system communicably coupled to a server system is detected. A transaction identification (ID) code is generated on the mobile electronic device. A display of an icon displayed in the user interface is changed. The icon depicts a status of the one or more light emitting elements. The transaction identification code and a request to change the lighting state to be transmitted from the mobile electronic device to the server system. A change notification received by the server system is analyzed to determine if it includes the transaction ID code. The display state of the icon is either changed on maintained based on the analysis.

Abstract: The present disclosure relates to a backlight control method and apparatus for a backlight module, a display device and a computer readable storage medium. The backlight module includes a plurality of backlight partitions. The backlight control method includes, for each backlight partition: determining a first brightness change threshold according to an output backlight brightness corresponding to a previous frame image; and determining, according to a difference between an initial backlight brightness of a current frame image and the output backlight brightness corresponding to the previous frame image and the first brightness change threshold, the output backlight brightness corresponding to the current frame image.

Abstract: A powering circuit for a diode light source includes an inductor charged through an on/off switch. The charging occurs during a charging cycle for a controllable amount of time when the on/off switch is closed. The energy of the charged inductor is used to power the semiconductor light source by opening the on/off switch. In such a driving configuration, the ringing is nearly constant and thus may be suppressed using an appropriately configured circuit.

Abstract: A display device and a method of compensating the same are provided. The display device includes a display panel, an optical sensor, and a control unit. The optical sensor is disposed behind the display panel and configured to provide first optically sensed data and second optically sensed data. The control unit is electrically connected the optical sensor and the display panel and configured to determine service life of the display panel based on the first optically sensed data and the second optically sensed data and provide a compensation to the display panel.

Abstract: An LED driver configured to power a plurality of LEDs having a different colour or colour spectrum is described, the LED driver comprising: a power converter configured to supply power to the plurality of LEDs and a control unit, the control unit comprising: an input terminal configured to receive an input signal representing a desired colour set-point; a processing unit configured to: determine a MacAdam ellipse for the desired colour set-point; determine a required intensity or current for each of the plurality of LEDs so as to achieve the desired colour set-point; determine a colour shift direction for the colour set-point, based on the determined required intensities or currents; select a modified colour set-point based on the colour shift direction and the MacAdam ellipse; determine a required supply current for each of the plurality of LEDs so as to achieve the modified colour set-point; determine a control signal for the power converter so as to generate the required supply currents; and wherein

Abstract: The invention is directed at a remote-control device for controlling one or more user devices, comprising a directional optical sensor for receiving one or more optical signals from the user devices. Each optical signal encodes a device identifier by high and low signal states in periods having granulated lengths. Each granulated length is an integer number of clock periods of a transmitter clock. The transmitter clock has a clock ratio to the predetermined receiver clock, the clock ratio being a number larger than one. At least one granulated length is longer than an integer number of clock periods of the predetermined receiver clock by a fraction of the clock period of the predetermined receiver clock, which granulated length may be detected by an asynchronous receiver clock and a detection range having only two values.

Abstract: The invention discloses an intelligent lighting control system based on Internet of Things, comprising a gateway, a cloud server a plurality of DALI systems, each DALI system includes a DALI bus 100 connected to the gateway, and each DALI bus is provided with a power node, a plurality of execution nodes, a plurality of control nodes and a plurality of sensor nodes, and the number of execution nodes on each DALI bus ranges from 1 to 64; the intelligent terminal can perform data interaction with any one of the nodes in any DALI system under the gateway. In the present invention, a single gateway can provide up to 256 execution nodes, which can be applied to construct a large and complex lighting control system.

Abstract: A method for light sensing senses the light during a sub-frame of a picture frame operated display. The sensing is performed during an adaptive observation window which is determined in dependence on the duty cycle of the operation of the display. A calculation that uses the light sensed during the observation window and the light sensed during the sub-frame delivers a value indicative of the amount of received ambient light.

Abstract: A luminaire can include a housing having at least one outer surface that forms a cavity. The luminaire can also include at least one electrical component disposed, at least in part, within the cavity. The luminaire can further include an electrical cable having a first end and a second end, where the first end is coupled to the at least one electrical component. The luminaire can also include a switch coupled to the electrical cable, where the switch is disposed remotely from the housing, where the switch has multiple positions, wherein each position of the switch corresponds to a discrete photometric distribution emitted by one or more light sources of the luminaire.

Abstract: A light source device has light source module. The light source module has a light source assembly having a plurality of light source combinations. The light source combinations are arranged around a central axis. Each of the light source combinations has an excitation light source and a reflecting article. The reflecting article is disposed between the excitation light source and the central axis for reflecting an excitation light of the excitation light source to form an illumination beam. A type of the excitation light sources of the light source module is composed of a red excitation source, a green excitation source, and a blue excitation source. A projection apparatus has the light source device, a light valve, and a projection lens. The light source device and the projection apparatus have advantages of improving the utilization efficiency of condenser lens, simple configuration, low cost, and wide color gamut.

Abstract: The purpose of the present invention is to provide a compound that can improve the lifespan, low drive voltage and high luminous efficiency of an element, an organic electronic element using same, and an electronic device comprising same.

Abstract: A luminaire includes a housing, a downlight that includes one or more first light sources configured to emit a first light downwardly from the housing, a waveguide, and one or more second light sources. The waveguide is formed of a portion of an optical material and characterized by opposing planar faces joined by one or more edge faces about a periphery of the optical material. The waveguide forms at least a portion of an uppermost optical surface of the luminaire. The one or more second light sources are coupled with the housing and configured to emit a second light into the optical material through at least one of the one or more edge faces. The waveguide is configured to emit at least a portion of the second light upwardly from an upper one of the planar faces.

Abstract: A method for detecting luminance uniformity of a screen, storage medium, and electronic device are provided. The method includes the following steps. At least one pixel on a display panel of a screen is lit. Light intensity of the pixel reflected by a non-opaque cover plate is acquired by a photoelectric sensor of the screen. Whether the pixel is uniformly luminous based on the acquired light intensity is determined. In this solution, by adding a photoelectric sensor to the screen, it is convenient to obtain the light condition of the screen, and then it is convenient to obtain whether the pixel is uniformly luminous.

Abstract: A color adjusting method for a color light-emitting element is provided. Firstly, a first white light beam is produced by red, green and blue light-emitting units collaboratively, and a second white light beam is produced by a white light-emitting unit. Then, a second chromaticity value corresponding to the second white light beam is acquired. Then, the red, green and blue light-emitting units are controlled to produce a third white light beam according to the second chromaticity value, and a first adjusting parameter is acquired. Then, the white light-emitting unit is controlled to produce a fourth white light beam according to a third luminance value corresponding to the third white light beam, and a second adjusting parameter is acquired. Then, a gray level adjustment process is performed according to the first and second adjusting parameters.

Abstract: A control method is provided for controlling a lighting system for automatically adjusting the colour temperature of the lighting system, by adjusting the colour temperature of the light emitted by the lighting system during one day according to a pre-set daily emission profile; the colour temperature emitted by the lighting system is progressively adjusted during the day according to a daily emission profile represented by a spline function consisting of a plurality of spline function portions corresponding to respective pre-set time periods; the daily emission profile is, moreover, modified based on a geographic position and, in particular, a latitude of the lighting system being controlled, as well as on the current date.

Abstract: A processing system for an optical sensing device may comprise receiver circuitry and a determination module. The processing system may also include drive circuitry configured to drive a light source to emit light. The receiver circuitry is coupled to a photodetector, and the receiver circuitry is configured to acquire a resulting signal from the photodetector, and generate a measurement of light received by the photodetector based on the resulting signal. The receiver circuitry includes high-pass filter circuitry configured to high-pass filter the resulting signal to generate a high-pass filtered signal based. The determination module is configured to generate a light measurement based on the high-pass filtered signal.

Abstract: A vehicle system includes an interface, an outlet, and a converter configured to, responsive to user input to the interface enabling shed mode, interrupt flow of battery current to internal vehicle loads such that power available at the outlet exceeds a predetermined threshold regardless of whether an external load is plugged into or removed from the outlet, and otherwise, maintain the flow regardless of whether an external load is plugged into the outlet.

Abstract: Provided is a power supply adjustment system including: an electronic load whose load voltage is variable; a power supply board that supplies the electronic load with current; and an information processing apparatus that controls the load voltage of the electronic load and the output current of the power supply board to the electronic load on the basis of a current value in the load voltage, in which the information processing apparatus includes a control unit that sets a plurality of load voltages in a predetermined range as the load voltage of the electronic load and sets a correction current value for adjusting the output current to a preset target current value for each of the plurality of load voltages.

Abstract: Systems and methods which leverage the wireless communication capability present in wireless-enabled luminaires where the lamps include a short-range wireless transceiver and can be controlled by a smart appliance. The wireless capability of a luminaire may be paired with a compatible wireless interface system (e.g., adapter system) that allows for control of the luminaire via plug-in or hard-wired photocontrols and wireless network lamp control nodes. An adapter system may be provided that replaces a standard wired receptacle of a luminaire. The adapter system may include a wired interface to the luminaire which provides power to the wireless adapter system. The wireless adapter system may include a receptacle interface that receives a plug of a control node, such as photocontrol or a networked control node. The wireless adapter system may also include a wireless interface circuit that communicates control, status or other data between the connected control device and the luminaire.

Abstract: An image capture apparatus that allows the user to easily change the brightness of an image that is shot while using automatic exposure control is disclosed. The image capture apparatus comprises a setting unit configured to be able to set a reference value of proper exposure. The image capture apparatus determines exposure conditions based on the luminance information and the reference value, wherein the reference value is a value used as a reference exposure value from which exposure conditions are varied in an exposure compensation.

Abstract: An optical member including a base substrate, a quantum dot layer disposed on the base substrate and having a first top surface including a lower wrinkle, the quantum dot layer including a medium layer and a plurality of quantum dots dispersed in the medium layer, a lower barrier layer disposed between the base substrate and the quantum dot layer, and an upper barrier layer covering the quantum dot layer, in which the upper barrier layer has a second top surface with an upper wrinkle corresponding to the lower wrinkle of the quantum dot layer.

Abstract: A light source module includes an array of illumination elements and a light diffusing material. The light source module is configured to receive a control signal for adjusting diffusion of light emitted from the light source module and in response adjust the amount of diffusion of light emitted from the light source module. A light source module may include a segmented light diffusing material where each segment is associated with an illumination element. And individual segments may have light diffusing properties that are different than other segments of the light diffusing material. Some illumination elements may emit light of a different color spectrum than other illumination elements, and a light diffusing material may scatter the different colored light to illuminate a scene with combinations of light of different colors. A light source module may be embedded in a mobile computing device.

Abstract: A projection apparatus includes a light source unit which time-divisionally emits light in colors by light emission from light emitting devices; a display element using light emitted from the light source unit, displaying images respectively corresponding to the colors of the emitted light, and forming optical images by reflection or transmission light thereof; a projection unit emitting the optical images formed by the display element toward a projection target; a timing setting unit setting a change timing associated with changing each of the colors, and setting spoke periods generated at each change timing; a light source drive unit driving the light source unit, based on the change timings and spoke periods; a detection unit detecting information indicating a light amount of the light for each of the colors emitted from the projection unit during the spoke periods; and a light source controller setting a delay time for light emission timings at the light source unit in the spoke periods by the light sourc

Abstract: A pixel circuit comprising an organic light emitting diode; a driving transistor including a gate, a source connected to a first node, a drain connected to a second power supply terminal; and a photosensitive circuit connected between a second node and a third node, the second node configured to receive a reference voltage. The driving transistor is configured to, responsive to a gate voltage and a source voltage, control a magnitude of a driving current flowing through the organic light emitting diode. The photosensitive circuit is configured to sense an intensity of light emission of the organic light emitting diode and to set a potential at the third node according to the reference voltage and the intensity that was sensed, the potential that was set being detectable by an external circuit via a sense line.

Abstract: Some embodiments include a method of operating a tunable light module. The method can include driving a lamp in the tunable light module, having lamps of at least two colors, to produce a colored light according to the color mixing plan that corresponds to a correlated color temperature (CCT); measuring a light characteristic of the lamp using a light sensor; detecting a degradation level by comparing the measured light characteristic against an expected light characteristic; and adjusting a current level for driving the lamp at the CCT by referencing the color mixing plan and an alternative coefficient corresponding to the degradation level.

Abstract: A lighting device includes an ultra-wideband (UWB) sensor module configured to detect movement, a light source module having a plurality of light emitting diodes (LEDs), and a driver configured to drive the plurality of LEDs, and a first controller connected to the light source module and the UWB sensor module, the first controller being configured to receive setting data from an external control device, output the setting data to the UWB sensor module to cause the UWB sensor module to set at least one operational parameter of the UWB sensor module, and output a control signal to the driver to cause the driver to drive the plurality of LEDs.

Abstract: Systems and methods to provide multiple channels of light to form a blended white light output, the systems and methods utilizing recipient luminophoric mediums to alter light provided by light emitting diodes. The predetermined blends of luminescent materials within the luminophoric mediums provide predetermined spectral power distributions in the white light output.

Abstract: Lighting systems and methods for lighting fixture location mapping, for example, using a combination of photosensing readings and/or other sensors to identify a correct mapping. These systems and methods may be used to resolve ambiguities that could not be resolved using other processes, such an auto-commissioning method that identifies more than one possible mapping of the lighting fixtures to spatial locations. Such ambiguities are typically found in floor plans that are symmetrical. The systems and methods of the present invention record and utilize environmental profiles, such as ambient lighting levels and occupancy patterns, to match lighting fixtures to their respective spatial locations and provide resolution to ambiguities in an auto-commissioning method that identifies more than one possible mapping of the lighting fixtures to spatial locations.

Abstract: A powering circuit for a diode light source includes an inductor charged through an on/off switch. The charging occurs during a charging cycle for a controllable amount of time when the on/off switch is closed. The energy of the charged inductor is used to power the semiconductor light source by opening the on/off switch. In such a driving configuration, the ringing is nearly constant and thus may be suppressed using an appropriately configured circuit.

Abstract: A distributed lighting control system has a plurality of independently controlled light fixtures. Each light fixture of the plurality of independently controlled light fixtures includes: an illuminating element; driver circuitry operatively coupled to the illuminating element and configured to provide power to the illuminating element; one or more sensors; and a processor operatively coupled to the one or more sensors and the driver circuitry. The processor is configured to: receive signals from the one or more sensors; and control the driver circuitry to provide power to the illuminating element to generate illumination based on the received signals from the one or more sensors. Illumination provided by each light fixture of the plurality of independently controlled light fixtures is controlled independently of the illumination provided by others of the plurality of independently controlled light fixtures.

Abstract: A luminaire can include a housing having at least one outer surface that forms a cavity. The luminaire can also include an aperture that traverses the at least one outer surface of the housing. The luminaire can further include a substrate disposed within the cavity. The luminaire can also include an electrical connector disposed on the substrate adjacent to the aperture. The luminaire can further include a dial coupled to the electrical connector, where dial has a range of positions, where each position within the range of positions of the dial corresponds to a discrete correlated color temperature (CCT) output by multiple light sources of the luminaire.

Abstract: A display device includes: an illuminating unit having a light source unit emitting light; an illumination control unit controlling the illuminating unit; a display element forming an image using illuminating light from the illuminating unit; a display control unit controlling the display element; a control unit controlling the illumination control unit and the display control unit based on a video signal; and a detection unit detecting the output intensity of the light source unit at that time. The control unit stores a control value corresponding to a target output intensity of the light source unit, and based on a difference between the to target output intensity and the output intensity at that time, the control unit determines a correction value for correcting the control value, and based on a control correction value obtained by correcting the control value using the correction value, the illumination control unit drives the light source unit.

Abstract: Provided is an an LED electronic bulletin board enabling high-speed image calibration, which is configured to apply brightness calibration data in consideration of brightness characteristics according to a brightness value through determination of whether or not there is a difference in a brightness value of a pixel or a part of an expression portion of the LED electronic bulletin board, which is to be expressed, with respect to image information inputted through a pixel capacitor controller installed between an image input device and a main controller unit (MCU), and then calibrate the image data inputted in real-time to express brightness-calibrated image data on the LED electronic bulletin board so that the image brightness of the electronic bulletin board can be calibrated irrespective of a configuration of an electronic bulletin board expression driving circuit.

Abstract: The present disclosure provides a display apparatus and an operating method thereof. The display apparatus includes a control unit and a display module. The control unit outputs a first signal. The display module is coupled to the control unit, and the display module continuously displays a first image in a first period based on the first signal, in which the first image has a first pattern, and a first ratio of an area of the first pattern to an area of the first image ranges from 5% to 30%. The first pattern has a first brightness at a first time point in the first period, and the first pattern has a second brightness at a second time point in the first period. The second time point is later than the first time point, and the second brightness is less than the first brightness.

Abstract: There are provided a circuit device for emitting heat to the outside and a backlight unit including the same. The present invention relates to a display device, a backlight unit connected to a display panel, or a constituent element thereof. The circuit device generates heat, and one or more heat emitting units for emitting heat generated from the light source of the backlight unit to the outside are added to the circuit device, and the backlight unit controlled by the aforementioned circuit device is provided. Each of the heat emitting units according to one embodiment of the present invention includes two or more different material layers to fix the circuit device and provide a heat emitting/directing function.

Abstract: LED luminaires including an LED engine as the vehicle for programming the LED driver. An example luminaire includes an LED engine including a non-transitory memory having driver parameters and an LED driver coupled to the LED engine. The LED driver is configured to receive the driver parameters from the non-transitory memory and to provide a power based on the driver parameters. The luminaire further includes a plurality of LEDs to be driven by the power from the LED driver.

Abstract: A luminaire can include a housing having at least one outer surface that forms a cavity. The luminaire can also include at least one electrical component disposed, at least in part, within the cavity. The luminaire can further include an electrical cable having a first end and a second end, where the first end is coupled to the at least one electrical component. The luminaire can also include a switch coupled to the electrical cable, where the switch is disposed remotely from the housing, where the switch has multiple positions, wherein each position of the switch corresponds to a discrete lumen output emitted by one or more light sources of the luminaire.

Abstract: Described herein is method for operating and controlling a network of lights comprising a plurality of lights arranged in a number of groups (A, B) using a short-distance network. Each light includes a control module (23, 28) for controlling its normal operation and for short-distance communication over the short-distance network with a designated group controller (23?, 28?, 31, 32) and other control modules within the group. Each designated group controller (23?, 28?, 31, 32) is also operable for long-distance communication with a central server and transmits its own specific information as a control module as well as information received from other control modules within the group. Information relevant to more than one group can quickly be exchanged between adjacent groups over a long-distance network via the group controller of the adjacent groups, by-passing the central server, or directly over the short-distance connection to a control module of an adjacent group.