DETAILED DESCRIPTION

[0159] Various embodiments of the present invention are described below, including certain embodiments relating particularly to LED-based light sources. It should be appreciated, however, that the present invention is not limited to any particular manner of implementation, and that the various embodiments discussed explicitly herein are primarily for purposes of illustration. For example, the various concepts discussed herein may be suitably implemented in a variety of environments involving LED-based light sources, other types of light sources not including LEDs, environments that involve both LEDs and other types of light sources in combination, and environments that involve non-lighting-related devices alone or in combination with various types of light sources.

[0160] FIG. 1 illustrates one example of a lighting unit 100 that may serve as a device in a lighting environment according to one embodiment of the present invention. Some examples of LED-based lighting units similar to those that are described below in connection with FIG. 1 may be found, for example, in U.S. Pat. No. 6,016,038, issued Jan. 18, 2000 to Mueller et al., entitled “Multicolored LED Lighting Method and Apparatus,” and U.S. Pat. No. 6,211,626, issued Apr. 3, 2001 to Lys et al, entitled “Illumination Components,” which patents are both hereby incorporated herein by reference.

[0161] In various embodiments of the present invention, the lighting unit 100 shown in FIG. 1 may be used alone or together with other similar lighting units in a system of lighting units (e.g., as discussed further below in connection with FIG. 2 ). Used alone or in combination with other lighting units, the lighting unit 100 may be employed in a variety of applications including, but not limited to, interior or exterior space illumination in general, direct or indirect illumination of objects or spaces, theatrical or other entertainment-based/special effects illumination, decorative illumination, safety-oriented illumination, vehicular illumination, illumination of displays and/or merchandise (e.g. for advertising and/or in retail/consumer environments), combined illumination and communication systems, etc., as well as for various indication and informational purposes.

[0162] Additionally, one or more lighting units similar to that described in connection with FIG. 1 may be implemented in a variety of products including, but not limited to, various forms of light modules or bulbs having various shapes and electrical/mechanical coupling arrangements (including replacement or “retrofit” modules or bulbs adapted for use in conventional sockets or fixtures), as well as a variety of consumer and/or household products (e.g., night lights, toys, games or game components, entertainment components or systems, utensils, appliances, kitchen aids, cleaning products, etc.).

[0163] In one embodiment, the lighting unit 100 shown in FIG. 1 may include one or more light sources 104 A, 104 B, 104 C, and 104 D wherein one or more of the light sources may be an LED-based light source that includes one or more light emitting diodes (LEDs). In one aspect of this embodiment, any two or more of the light sources 104 A, 104 B, 104 C and 104 D may be adapted to generate radiation of different colors (e.g. red, green, and blue, respectively). Although FIG. 1 shows four light sources 104 A, 104 B, 104 C, and 104 D, it should be appreciated that the lighting unit is not limited in this respect, as different numbers and various types of light sources (all LED-based light sources, LED-based and non-LED-based light sources in combination, etc.) adapted to generate radiation of a variety of different colors, including essentially white light, may be employed in the lighting unit 100 , as discussed further below.

[0164] As shown in FIG. 1 , the lighting unit 100 also may include a processor 102 that is configured to output one or more control signals to drive the light sources 104 A, 104 B, 104 C and 104 D so as to generate various intensities of light from the light sources. For example, in one implementation, the processor 102 may be configured to output at least one control signal for each light source so as to independently control the intensity of light generated by each light source. Some examples of control signals that may be generated by the processor to control the light sources include, but are not limited to, pulse modulated signals, pulse width modulated signals (PWM), pulse amplitude modulated signals (PAM), pulse displacement modulated signals, analog control signals (e.g., current control signals, voltage control signals), combinations and/or modulations of the foregoing signals, or other control signals. In one aspect, the processor 102 may control other dedicated circuitry (not shown in FIG. 1 ), which in turn controls the light sources so as to vary their respective intensities.

[0165] Lighting systems in accordance with this specification can operate LEDs in an efficient manner. Typical LED performance characteristics depend on the amount of current drawn by the LED. The optimal efficacy may be obtained at a lower current than the level where maximum brightness occurs. LEDs are typically driven well above their most efficient operating current to increase the brightness delivered by the LED while maintaining a reasonable life expectancy. As a result, increased efficacy can be provided when the maximum current value of the PWM signal may be variable. For example, if the desired light output is less than the maximum required output the current maximum and/or the PWM signal width may be reduced. This may result in pulse amplitude modulation (PAM), for example; however, the width and amplitude of the current used to drive the LED may be varied to optimize the LED performance. In an embodiment, a lighting system may also be adapted to provide only amplitude control of the current through the LED. While many of the embodiments provided herein describe the use of PWM and PAM to drive the LEDs, one skilled in the art would appreciate that there are many techniques to accomplish the LED control described herein and, as such, the scope of the present invention is not limited by any one control technique. In embodiments, it is possible to use other techniques, such as pulse frequency modulation (PFM), or pulse displacement modulation (PDM), such as in combination with either or both of PWM and PAM.

[0166] Pulse width modulation (PWM) involves supplying a substantially constant current to the LEDs for particular periods of time. The shorter the time, or pulse-width, the less brightness an observer will observe in the resulting light. The human eye integrates the light it receives over a period of time and, even though the current through the LED may generate the same light level regardless of pulse duration, the eye will perceive short pulses as “dimmer” than longer pulses. The PWM technique is considered on of the preferred techniques for driving LEDs, although the present invention is not limited to such control techniques. When two or more colored LEDs are provided in a lighting system, the colors may be mixed and many variations of colors can be generated by changing the intensity, or perceived intensity, of the LEDs. In an embodiment, three colors of LEDs are presented (e.g., red, green and blue) and each of the colors is driven with PWM to vary its apparent intensity. This system allows for the generation of millions of colors (e.g., 16.7 million colors when 8-bit control is used on each of the PWM channels).

[0167] In an embodiment the LEDs are modulated with PWM as well as modulating the amplitude of the current driving the LEDs (Pulse Amplitude Modulation, or PAM). FIG. 15 illustrates an LED efficiency curve 1502 . As can be seen from FIG. 15 , the LED efficiency increases to a maximum followed by decreasing efficiency. Typically, LEDs are driven at a current level beyond its maximum efficiency to attain greater brightness while maintaining acceptable life expectancy. The objective is typically to maximize the light output from the LED while maintaining an acceptable lifetime. In an embodiment, the LEDs may be driven with a lower current maximum when lower intensities are desired. PWM may still be used, but the maximum current intensity may also be varied depending on the desired light output. For example, to decrease the intensity of the light output from a maximum operational point such as 1504 , the amplitude of the current may be decreased until the maximum efficiency is achieved. If further reductions in the LED brightness are desired the PWM activation may be reduced to reduce the apparent brightness.

[0168] In one embodiment of the lighting unit 100 , one or more of the light sources 104 A, 104 B, 104 C and 104 D shown in FIG. 1 may include a group of multiple LEDs or other types of light sources (e.g., various parallel and/or serial connections of LEDs or other types of light sources) that are controlled together by the processor 102 . Additionally, it should be appreciated that one or more of the light sources 104 A, 104 B, 104 C and 104 D may include one or more LEDs that are adapted to generate radiation having any of a variety of spectra (i.e., wavelengths or wavelength bands), including, but not limited to, various visible colors (including essentially white light), various color temperatures of white light, ultraviolet, or infrared.

[0169] In another aspect of the lighting unit 100 shown in FIG. 1 , the lighting unit 100 may be constructed and arranged to produce a wide range of variable color radiation. For example, the lighting unit 100 may be particularly arranged such that the processor-controlled variable intensity light generated by two or more of the light sources combines to produce a mixed colored light (including essentially white light having a variety of color temperatures). In particular, the color (or color temperature) of the mixed colored light may be varied by varying one or more of the respective intensities of the light sources (e.g., in response to one or more control signals output by the processor 102 ). Furthermore, the processor 102 may be particularly configured (e.g., programmed) to provide control signals to one or more of the light sources so as to generate a variety of static or time-varying (dynamic) multi-color (or multi-color temperature) lighting effects.

[0170] As shown in FIG. 1 , the lighting unit 100 also may include a memory 114 to store various information. For example, the memory 114 may be employed to store one or more lighting programs for execution by the processor 102 (e.g., to generate one or more control signals for the light sources), as well as various types of data useful for generating variable color radiation (e.g., calibration information, discussed further below). The memory 114 also may store one or more particular identifiers (e.g., a serial number, an address, etc.) that may be used either locally or on a system level to identify the lighting unit 100 . In various embodiments, such identifiers may be pre-programmed by a manufacturer, for example, and may be either alterable or non-alterable thereafter (e.g., via some type of user interface located on the lighting unit, via one or more data or control signals received by the lighting unit, etc.). Alternatively, such identifiers may be determined at the time of initial use of the lighting unit in the field, and again may be alterable or non-alterable thereafter.

[0171] One issue that may arise in connection with controlling multiple light sources in the lighting unit 100 of FIG. 1 , and controlling multiple lighting units 100 in a lighting system (e.g., as discussed below in connection with FIG. 2 ), relates to potentially perceptible differences in light output between substantially similar light sources. For example, given two virtually identical light sources being driven by respective identical control signals, the actual intensity of light output by each light source may be perceptibly different. Such a difference in light output may be attributed to various factors including, for example, slight manufacturing differences between the light sources, normal wear and tear over time of the light sources that may differently alter the respective spectrums of the generated radiation, etc. For purposes of the present discussion, light sources for which a particular relationship between a control signal and resulting intensity are not known are referred to as “uncalibrated” light sources.

[0172] The use of one or more uncalibrated light sources in the lighting unit 100 shown in FIG. 1 may result in generation of light having an unpredictable, or “uncalibrated,” color or color temperature. For example, consider a first lighting unit including a first uncalibrated red light source and a first uncalibrated blue light source, each controlled by a corresponding control signal having an adjustable parameter in a range of from zero to 255 (0-255). For purposes of this example, if the red control signal is set to zero, blue light is generated, whereas if the blue control signal is set to zero, red light is generated. However, if both control signals are varied from non-zero values, a variety of perceptibly different colors may be produced (e.g., in this example, at very least, many different shades of purple are possible). In particular, perhaps a particular desired color (e.g., lavender) is given by a red control signal having a value of 125 and a blue control signal having a value of 200.

[0173] Now consider a second lighting unit including a second uncalibrated red light source substantially similar to the first uncalibrated red light source of the first lighting unit, and a second uncalibrated blue light source substantially similar to the first uncalibrated blue light source of the first lighting unit. As discussed above, even if both of the uncalibrated red light sources are driven by respective identical control signals, the actual intensity of light output by each red light source may be perceptibly different. Similarly, even if both of the uncalibrated blue light sources are driven by respective identical control signals, the actual intensity of light output by each blue light source may be perceptibly different.

[0174] With the foregoing in mind, it should be appreciated that if multiple uncalibrated light sources are used in combination in lighting units to produce a mixed colored light as discussed above, the observed color (or color temperature) of light produced by different lighting units under identical control conditions may be perceivably different. Specifically, consider again the “lavender” example above; the “first lavender” produced by the first lighting unit with a red control signal of 125 and a blue control signal of 200 indeed may be perceptibly different than a “second lavender” produced by the second lighting unit with a red control signal of 125 and a blue control signal of 200. More generally, the first and second lighting units generate uncalibrated colors by virtue of their uncalibrated light sources.

[0175] In view of the foregoing, in one embodiment of the present invention, the lighting unit 100 includes calibration means to facilitate the generation of light having a calibrated (e.g., predictable, reproducible) color at any given time. In one aspect, the calibration means is configured to adjust the light output of at least some light sources of the lighting unit so as to compensate for perceptible differences between similar light sources used in different lighting units.

[0176] For example, in one embodiment, the processor 102 of the lighting unit 100 is configured to control one or more of the light sources 104 A, 104 B, 104 C and 104 D so as to output radiation at a calibrated intensity that substantially corresponds in a predetermined manner to a control signal for the light source(s). As a result of mixing radiation having different spectra and respective calibrated intensities, a calibrated color is produced. In one aspect of this embodiment, at least one calibration value for each light source is stored in the memory 114 , and the processor is programmed to apply the respective calibration values to the control signals for the corresponding light sources so as to generate the calibrated intensities.

[0177] In one aspect of this embodiment, one or more calibration values may be determined once (e.g., during a lighting unit manufacturing/testing phase) and stored in the memory 114 for use by the processor 102 . In another aspect, the processor 102 may be configured to derive one or more calibration values dynamically (e.g. from time to time), with the aid of one or more photosensors, for example. In various embodiments, the photosensor(s) may be one or more external components coupled to the lighting unit, or alternatively may be integrated as part of the lighting unit itself. A photosensor is one example of a signal source that may be integrated or otherwise associated with the lighting unit 100 , and monitored by the processor 102 in connection with the operation of the lighting unit. Other examples of such signal sources are discussed further below, in connection with the signal source 124 shown in FIG. 1 .

[0178] One exemplary method that may be implemented by the processor 102 to derive one or more calibration values includes applying a reference control signal to a light source, and measuring (e.g., via one or more photosensors) an intensity of radiation thus generated by the light source. The processor may be programmed to then make a comparison of the measured intensity and at least one reference value (e.g., representing an intensity that nominally would be expected in response to the reference control signal). Based on such a comparison, the processor may determine one or more calibration values for the light source. In particular, the processor may derive a calibration value such that, when applied to the reference control signal, the light source outputs radiation having an intensity that corresponds to the reference value (i.e., the “expected” intensity).

[0179] In various aspects, one calibration value may be derived for an entire range of control signal/output intensities for a given light source. Alternatively, multiple calibration values may be derived for a given light source (i.e., a number of calibration value “samples” may be obtained) that are respectively applied over different control signal/output intensity ranges, to approximate a nonlinear calibration function in a piecewise linear manner.

[0180] In another aspect, as also shown in FIG. 1 , the lighting unit 100 optionally may include one or more user interfaces 118 that are provided to facilitate any of a number of user-selectable settings or functions (e.g., generally controlling the light output of the lighting unit 100 , changing and/or selecting various pre-programmed lighting effects to be generated by the lighting unit, changing and/or selecting various parameters of selected lighting effects, setting particular identifiers such as addresses or serial numbers for the lighting unit, etc.). In various embodiments, the communication between the user interface 118 and the lighting unit may be accomplished through wire or cable, or wireless transmission.

[0181] In one implementation, the processor 102 of the lighting unit monitors the user interface 118 and controls one or more of the light sources 104 A, 104 B, 104 C and 104 D based at least in part on a user's operation of the interface. For example, the processor 102 may be configured to respond to operation of the user interface by originating one or more control signals for controlling one or more of the light sources. Alternatively, the processor 102 may be configured to respond by selecting one or more pre-programmed control signals stored in memory, modifying control signals generated by executing a lighting program, selecting and executing a new lighting program from memory, or otherwise affecting the radiation generated by one or more of the light sources.

[0182] In particular, in one implementation, the user interface 118 may constitute one or more switches (e.g., a standard wall switch) that interrupt power to the processor 102 . In one aspect of this implementation, the processor 102 is configured to monitor the power as controlled by the user interface, and in turn control one or more of the light sources 104 A, 104 B, 104 C and 104 D based at least in part on a duration of a power interruption caused by operation of the user interface. As discussed above, the processor may be particularly configured to respond to a predetermined duration of a power interruption by, for example, selecting one or more pre-programmed control signals stored in memory, modifying control signals generated by executing a lighting program, selecting and executing a new lighting program from memory, or otherwise affecting the radiation generated by one or more of the light sources.

[0183] FIG. 1 also illustrates that the lighting unit 100 may be configured to receive one or more signals 122 from one or more other signal sources 124 . In one implementation, the processor 102 of the lighting unit may use the signal(s) 122 , either alone or in combination with other control signals (e.g., signals generated by executing a lighting program, one or more outputs from a user interface, etc.), so as to control one or more of the light sources 104 A, 104 B, 104 C and 104 D in a manner similar to that discussed above in connection with the user interface.

[0184] Examples of the signal(s) 122 that may be received and processed by the processor 102 include, but are not limited to, one or more audio signals, video signals, power signals, various types of data signals, signals representing information obtained from a network (e.g., the Internet), signals representing some detectable/sensed condition, signals from lighting units, signals consisting of modulated light, etc. In various implementations, the signal source(s) 124 may be located remotely from the lighting unit 100 , or included as a component of the lighting unit. For example, in one embodiment, a signal from one lighting unit 100 could be sent over a network to another lighting unit 100 .

[0185] Some examples of a signal source 124 that may be employed in, or used in connection with, the lighting unit 100 of FIG. 1 include any of a variety of sensors or transducers that generate one or more signals 122 in response to some stimulus. Examples of such sensors include, but are not limited to, various types of environmental condition sensors, such as thermally sensitive (e.g., temperature, infrared) sensors, humidity sensors, motion sensors, photosensors/light sensors (e.g., sensors that are sensitive to one or more particular spectra of electromagnetic radiation), sound or vibration sensors or other pressure/force transducers (e.g., microphones, piezoelectric devices), and the like.

[0186] Additional examples of a signal source 124 include various metering/detection devices that monitor electrical signals or characteristics (e.g., voltage, current, power, resistance, capacitance, inductance, etc.) or chemical/biological characteristics (e.g., acidity, a presence of one or more particular chemical or biological agents, bacteria, etc.) and provide one or more signals 122 based on measured values of the signals or characteristics. Yet other examples of a signal source 124 include various types of scanners, image recognition systems, voice or other sound recognition systems, artificial intelligence and robotics systems, and the like.

[0187] A signal source 124 could also be a lighting unit 100 , a processor 102 , or any one of many available signal generating devices, such as media players, MP3 players, computers, DVD players, CD players, television signal sources, camera signal sources, microphones, speakers, telephones, cellular phones, instant messenger devices, SMS devices, wireless devices, personal organizer devices, and many others.

[0188] In one embodiment, the lighting unit 100 shown in FIG. 1 also may include one or more optical facilities 130 to optically process the radiation generated by the light sources 104 A, 104 B, 104 C and 104 D. For example, one or more optical facilities may be configured so as to change one or both of a spatial distribution and a propagation direction of the generated radiation. In particular, one or more optical facilities may be configured to change a diffusion angle of the generated radiation. In one aspect of this embodiment, one or more optical facilities 130 may be particularly configured to variably change one or both of a spatial distribution and a propagation direction of the generated radiation (e.g., in response to some electrical and/or mechanical stimulus). Examples of optical facilities that may be included in the lighting unit 100 include, but are not limited to, reflective materials, refractive materials, translucent materials, filters, lenses, mirrors, and fiber optics. The optical facility 130 also may include a phosphorescent material, luminescent material, or other material capable of responding to or interacting with the generated radiation.

[0189] As also shown in FIG. 1 , the lighting unit 100 may include one or more communication ports 120 to facilitate coupling of the lighting unit 100 to any of a variety of other devices. For example, one or more communication ports 120 may facilitate coupling multiple lighting units together as a networked lighting system, in which at least some of the lighting units are addressable (e.g., have particular identifiers or addresses) and are responsive to particular data transported across the network.

[0190] In particular, in a networked lighting system environment, as discussed in greater detail further below (e.g., in connection with FIG. 2 ), as data is communicated via the network, the processor 102 of each lighting unit coupled to the network may be configured to be responsive to particular data (e.g., lighting control commands) that pertain to it (e.g., in some cases, as dictated by the respective identifiers of the networked lighting units). Once a given processor identifies particular data intended for it, it may read the data and, for example, change the lighting conditions produced by its light sources according to the received data (e.g., by generating appropriate control signals to the light sources). In one aspect, the memory 114 of each lighting unit coupled to the network may be loaded, for example, with a table of lighting control signals that correspond with data the processor 102 receives. Once the processor 102 receives data from the network, the processor may consult the table to select the control signals that correspond to the received data, and control the light sources of the lighting unit accordingly.

[0191] In one aspect of this embodiment, the processor 102 of a given lighting unit, whether or not coupled to a network, may be configured to interpret lighting instructions/data that are received in a DMX protocol (as discussed, for example, in U.S. Pat. Nos. 6,016,038 and 6,211,626), which is a lighting command protocol conventionally employed in the lighting industry for some programmable lighting applications. However, it should be appreciated that lighting units suitable for purposes of the present invention are not limited in this respect, as lighting units according to various embodiments may be configured to be responsive to other types of communication protocols so as to control their respective light sources.

[0192] In one embodiment, the lighting unit 100 of FIG. 1 may include and/or be coupled to one or more power sources 108 . In various aspects, examples of power source(s) 108 include, but are not limited to, AC power sources, DC power sources, batteries, solar-based power sources, thermoelectric or mechanical-based power sources and the like. Additionally, in one aspect, the power source(s) 108 may include or be associated with one or more power conversion devices that convert power received by an external power source to a form suitable for operation of the lighting unit 100 .

[0193] While not shown explicitly in FIG. 1 , the lighting unit 100 may be implemented in any one of several different structural configurations according to various embodiments of the present invention. For example, a given lighting unit may have any one of a variety of mounting arrangements for the light source(s), enclosure/housing arrangements and shapes to partially or fully enclose the light sources, and/or electrical and mechanical connection configurations. In particular, a lighting unit may be configured as a replacement or “retrofit” to engage electrically and mechanically in a conventional socket or fixture arrangement (e.g., an Edison-type screw socket, a halogen fixture arrangement, a fluorescent fixture arrangement, etc.).

[0194] Additionally, one or more optical elements as discussed above may be partially or fully integrated with an enclosure/housing arrangement for the lighting unit. Furthermore, a given lighting unit optionally may be associated with (e.g., include, be coupled to and/or packaged together with) various other components (e.g., control circuitry such as the processor and/or memory, one or more sensors/transducers/signal sources, user interfaces, displays, power sources, power conversion devices, etc.) relating to the operation of the light source(s).

[0195] FIG. 2 illustrates an example of a networked lighting system 200 according to one embodiment of the present invention. In the embodiment of FIG. 2, a number of lighting units 100 , similar to those discussed above in connection with FIG. 1 , are coupled together to form the networked lighting system. It should be appreciated, however, that the particular configuration and arrangement of lighting units shown in FIG. 2 is for purposes of illustration only, and that the invention is not limited to the particular system topology shown in FIG. 2 .

[0196] Additionally, while not shown explicitly in FIG. 2 , it should be appreciated that the networked lighting system 200 may be configured flexibly to include one or more user interfaces, as well as one or more signal sources such as sensors/transducers. For example, one or more user interfaces and/or one or more signal sources such as sensors/transducers (as discussed above in connection with FIG. 1 ) may be associated with any one or more of the lighting units of the networked lighting system 200 . Alternatively (or in addition to the foregoing), one or more user interfaces and/or one or more signal sources may be implemented as “stand alone” components in the networked lighting system 200 . Whether stand alone components or particularly associated with one or more lighting units 100 , these devices may be “shared” by the lighting units of the networked lighting system. Stated differently, one or more user interfaces and/or one or more signal sources such as sensors/transducers may constitute “shared resources” in the networked lighting system that may be used in connection with controlling any one or more of the lighting units of the system.

[0197] As shown in the embodiment of FIG. 2 , the lighting system 200 may include one or more lighting unit controllers (hereinafter “LUCs”) 208 A, 208 B, 208 C and 208 D, wherein each LUC is responsible for communicating with and generally controlling one or more lighting units 100 coupled to it. Although FIG. 2 illustrates three lighting units 100 coupled in a serial fashion to a given LUC, it should be appreciated that the invention is not limited in this respect, as different numbers of lighting units 100 may be coupled to a given LUC in a variety of different configurations using a variety of different communication media and protocols.

[0198] In the system of FIG. 2 , each LUC in turn may be coupled to a central controller 202 that is configured to communicate with one or more LUCs. Although FIG. 2 shows three LUCs coupled to the central controller 202 via a switching or coupling device 204 , it should be appreciated that according to various embodiments, different numbers of LUCs may be coupled to the central controller 202 . Additionally, according to various embodiments of the present invention, the LUCs and the central controller may be coupled together in a variety of configurations using a variety of different communication media and protocols to form the networked lighting system 200 . Moreover, it should be appreciated that the interconnection of LUCs and the central controller, and the interconnection of lighting units to respective LUCs, may be accomplished in different manners (e.g., using different configurations, communication media, and protocols).

[0199] For example, according to one embodiment of the present invention, the central controller 202 shown in FIG. 2 may by configured to implement Ethernet-based communications with the LUCs, and in turn the LUCs may be configured to implement DMX-based communications with the lighting units 100 . In particular, in one aspect of this embodiment, each LUC may be configured as an addressable Ethernet-based controller and accordingly may be identifiable to the central controller 202 via a particular unique address (or a unique group of addresses) using an Ethernet-based protocol. In this manner, the central controller 202 may be configured to support Ethernet communications throughout the network of coupled LUCs, and each LUC may respond to those communications intended for it. In turn, each LUC may communicate lighting control information to one or more lighting units coupled to it, for example, via a DMX protocol, based on the Ethernet communications with the central controller 202 .

[0200] More specifically, according to one embodiment, the LUCs 208 A, 208 B, 208 C and 208 D shown in FIG. 2 may be configured to be “intelligent” in that the central controller 202 may be configured to communicate higher level commands to the LUCs that need to be interpreted by the LUCs before lighting control information can be forwarded to the lighting units 100 . For example, a lighting system operator may want to generate a color changing effect that varies colors from lighting unit to lighting unit in such a way as to generate the appearance of a propagating rainbow of colors (“rainbow chase”), given a particular placement of lighting units with respect to one another. In this example, the operator may provide a simple instruction to the central controller 202 to accomplish this, and in turn the central controller may communicate to one or more LUCs using an Ethernet-based protocol high-level command to generate a “rainbow chase.” The command may contain timing, intensity, hue, saturation or other relevant information, for example. When a given LUC receives such a command, it may then interpret the command so as to generate the appropriate lighting control signals which it then communicates using a DMX protocol via any of a variety of signaling techniques (e.g., PWM) to one or more lighting units that it controls.

[0201] It should again be appreciated that the foregoing example of using multiple different communication implementations (e.g., Ethernet/DMX) in a lighting system according to one embodiment of the present invention is for purposes of illustration only, and that the invention is not limited to this particular example.

[0202] Referring to FIG. 3 , various configurations can be provided for lighting systems 100 , in each case with an optional communications facility 120 . Configurations include a linear configuration 302 (which may be curvilinear in embodiments), a circular configuration 308 , an oval configuration 304 , or a collection of various configurations 302 , 304 , 308 . Lighting units 100 can also include a wide variety of colors of LED, in various mixtures, including red, green, and blue LEDs to produce a color mix, as well as one or more other LEDs to create varying colors and color temperatures of white light. For example, red, green and blue can be mixed with amber, white, UV, orange, IR or other colors of LED. Amber and white LEDs can be mixed to offer varying colors and color temperatures of white. Any combination of LED colors can produce a gamut of colors, whether the LEDs are red, green, blue, amber, white, orange, UV, or other colors. The various embodiments described throughout this specification encompass all possible combinations of LEDs in lighting units 100 , so that light of varying color, intensity, saturation and color temperature can be produced on demand under control of a processor 102 . Combinations of LEDs with other mechanisms, such as phosphors, are also encompassed herein.

[0203] Although mixtures of red, green and blue have been proposed for light due to their ability to create a wide gamut of additively mixed colors, the general color quality or color rendering capability of such systems are not ideal for all applications. This is primarily due to the narrow bandwidth of current red, green and blue emitters. However, wider band sources do make possible good color rendering, as measured, for example, by the standard CRI index. In some cases this may require LED spectral outputs that are not currently available. However, it is known that wider-band sources of light will become available, and such wider-band sources are encompassed as sources for lighting units 100 described herein.

[0204] Additionally, the addition of white LEDs (typically produced through a blue or UV LED plus a phosphor mechanism) does give a ‘better’ white it is still limiting in the color temperature that is controllable or selectable from such sources.

[0205] The addition of white to a red, green and blue mixture may not increase the gamut of available colors, but it can add a broader-band source to the mixture. The addition of an amber source to this mixture can improve the color still further by ‘filling in’ the gamut as well.

[0206] This combinations of light sources as lighting units 100 can help fill in the visible spectrum to faithfully reproduce desirable spectrums of lights. These include broad daylight equivalents or more discrete waveforms corresponding to other light sources or desirable light properties. Desirable properties include the ability to remove pieces of the spectrum for reasons that may include environments where certain wavelengths are absorbed or attenuated. Water, for example tends to absorb and attenuate most non-blue and non-green colors of light, so underwater applications may benefit from lights that combine blue and green sources for lighting units 100 .

[0207] Amber and white light sources can offer a color temperature selectable white source, wherein the color temperature of generated light can be selected along the black body curve by a line joining the chromaticity coordinates of the two sources. The color temperature selection is useful for specifying particular color temperature values for the lighting source.

[0208] Orange is another color whose spectral properties in combination with a white LED-based light source can be used to provide a controllable color temperature light from a lighting unit 100 .

[0209] The combination of white light with light of other colors as light sources for lighting units 100 can offer multi-purpose lights for many commercial and home applications, such as in pools, spas, automobiles, building interiors (commercial and residential), indirect lighting applications, such as alcove lighting, commercial point of purchase lighting, merchandising, toys, beauty, signage, aviation, marine, medical, submarine, space, military, consumer, under cabinet lighting, office furniture, landscape, residential including kitchen, home theater, bathroom, faucets, dining rooms, decks, garage, home office, household products, family rooms, tomb lighting, museums, photography, art applications, and many others.

[0210] Referring to FIG. 4 and the subsequent figures, LED systems, and most luminaires, can utilize fixed or static optical facilities 130 to shape and control the beam of light from the fixture. By contrast, variable optics provide discrete or continuous adjustment of beam spread or angle or simply the profile of the light beam emitted from a fixture. Properties can include, but are not limited to, adjusting the profile for surfaces that vary in distance from the fixture, such as wall washing fixtures. In various embodiments, the variable nature of the optic can be manually adjusted, adjusted by motion control or automatically be controlled dynamically.

[0211] Actuation of variable optics can be through any kind of actuator, such as an electric motor, piezoelectric device, thermal actuator, motor, gyro, servo, lever, gear, gear system, screw drive, drive mechanism, flywheel, wheel, or one of many well-known techniques for motion control. Manual control can be through an adjustment mechanism that varies the relative geometry of lens, diffusion materials, reflecting surfaces or refracting elements. The adjustment mechanism may use a sliding element, a lever, screws, or other simple mechanical devices or combinations of simple mechanical devices. A manual adjustment or motion control adjustment may allow the flexing of optical surfaces to bend and shape the light passed through the system or reflected or refracted by the optical system.

[0212] Actuation can also be through an electromagnetic motor or one of many actuation materials and devices. Optical facilities 130 can also include other actuators, such as piezo-electric devices, MEMS devices, thermal actuators, processors 102 , and many other forms of actuators.

[0213] A wide range of optical facilities 130 can be used to control light. Such devices as Bragg cells or holographic films can be used as optical facilities 130 to vary the output of a fixture. A Bragg cell or acoustic-optic modulator can provide for the movement of light with no other moving mechanisms. The combination of controlling the color (hue, saturation and value) as well as the form of the light beam brings a tremendous amount of operative control to a light source. The use of polarizing films can be used to reduce glare and allow the illumination and viewing of objects that present specular surfaces, which typically are difficult to view. Moving lenses and shaped non-imaging surfaces can provide optical paths to guide and shape light.

[0214] In other embodiments, fluid-filled surfaces and shapes can be manipulated to provide an optical path. In combination with lighting units 100 , such shapes can provide varying optical properties across the surface and volume of the fluid-filled material. The fluid-filled material can also provide a thermal dissipation mechanism for the light-emitting elements. The fluid can be water, polymers, silicone or other transparent or translucent liquid or a gas of any type and mixture with desirable optical or thermal properties.

[0215] In other embodiments, gelled, filled shapes can be used in conjunction with light sources to evenly illuminate said shapes. Light propagation and diffusion is accomplished through the scattering of light through the shape.

[0216] In other embodiments, spinning mirror systems such as those used in laser optics for scanning (E.g. bar code scanners or 3D terrain scanners) can be used to direct and move a beam of light. That combined with the ability to rapidly turn on and off a lighting unit 100 can allow a beam of light to be spread across a larger area and change colors to ‘draw’ shapes of varying patterns. Other optical facilities 130 for deflecting and changing light patterns are known and described in the literature. They include methods for beam steering, such as mechanical mirrors, driven by stepper or galvanometer motors and more complex robotic mechanisms for producing sophisticated temporal effects or static control of both color (HS&V) and intensity. Optical facilities 130 also include acousto-optic modulators that use sound waves generated via piezoelectrics to control and steer a light beam. They also include digital mirror devices and digital light processors, such as available from Texas Instruments. They also include grating light valve technology (GLV), as well as inorganic digital light deflection. They also include dielectric mirrors, such as developed at Massachusetts Institute of Technology.

[0217] Control of form and texture of the light can include not only control of the shape of the beam but control of the way in which the light is patterned across its beam. An example of a use of this technology may be in visual merchandising, where product ‘spotlights’ could be created while other media is playing in a coordinated manner. Voice-overs or music-overs or even video can be played during the point at which a product is highlighted during a presentation. Lights that move and ‘dance’ can be used in combination with A/V sources for visual merchandising purposes.

[0218] Additional material on variable optical facilities can be found in the following documents and publications, which are herein incorporated by reference: Optoelectronics, Fiber Optics, and Laser Cookbook by Thomas Petruzzellis 322 pages McGraw-Hill/TAB Electronics; ISBN: 0070498407; (May 1, 1997); Digital Diffractive Optics: An Introduction to Planar Diffractive Optics and Related Technology by B. Kress, Patrick Meyrueis. John Wiley & Sons ISBN: 0471984477; 1 edition (Oct. 25, 2000); Optical System Design by Robert E. Fischer, Biljana Tadic-Galeb, McGraw-Hill Professional; ISBN: 0071349162; 1st edition (Jun. 30, 2000); and Feynman Lectures On Physics (3 Volume Set) by Richard Phillips Feynman Addison-Wesley Pub Co; ISBN: 0201021153; (June 1970).

[0219] Optical facilities 130 can also comprise secondary optics, namely, optics (plastic, glass, imaging, non-imaging) added to an array of LEDs to shape and form the light emission. It can be used to spread, narrow, diffuse, diffract, refract or reflect the light in order that a different output property of the light is created. These can be fixed or variable. These can be light pipes, lenses, light guides and fibers and any other light transmitting materials.

[0220] In other embodiments, non-imaging optics are used as an optical facility 130 . Non-imaging optics do not use traditional lenses. They use shaped surfaces to diffuse and direct light. A fundamental issue with fixtures using discrete light sources is mixing the light to reduce or eliminate color shadows and to produce uniform and homogenous light output. Part of the issue is the use of high efficiency surfaces that do not absorb light but bounce and reflect the light in a desired direction or manner. Optical facilities 130 can be used to direct light to create optical forms of illumination from lighting units 100 .

[0221] Specific optical facilities 130 are of a wide variety. FIG. 4 depicts optical facilities 130 for optically operating on light from a lighting unit 100 . Included is an actuator 402 for actuating a change in the optical effect that is caused by the optical facility 130 . For example, as shown in FIG. 4 , the actuator 402 can be an electromechanical actuator that changes the direction of the optical facility 130 , in this case a lens 130 . The actuator 402 tilts, changing the direction of light that is received by the optical facility 130 from a lighting unit 100 .

[0222] FIG. 5 shows another form of actuation by an actuator 402 . In this case the actuator actuates a change in the optical facility, in this case a change in the width of the lens 130 . The lens can optionally include a compressible fluid, so that upon actuation it expands. Upon expansion the optical effect of the optical facility 130 is different than it was in the unexpanded state. The actuator 402 can actuate such a change by changing temperature of the material include in the optical facility, by mechanically changing a dimension of the optical facility 130 , by compressing a gas or other fluid material into the optical facility 130 , or the like. The actuator 402 can be under control of a processor or similar facility. The optical facility 130 can also tilt like the actuator 402 of FIG. 4 , so that a wide range of optical effects can be created, in each case operating on light from the lighting unit 100 .

[0223] Referring to FIG. 6, a processor 102 is used to operate both a lighting unit 100 and the actuator 402 of the optical facility 130 . Optionally, two processors 102 could be used in conjunction with the two elements. The processor 102 is in operative connection to a signal source 124 , so that that the processor 102 can receive input from the signal source 124 (and, optionally, operate in a feedback loop with the signal source 124 ). In embodiments the signal source 124 is a sensor. Thus, the processor 102 can provide control signals to the lighting unit 100 and the actuator 402 , to coordinate the lighting unit 100 with the optical facility 130 to produce a desired type of illumination or display. For example, the actuator 402 can be used to adjust the angle of the beam of light coming out of the lighting unit 100 , such as to diffuse light across a given portion of a surface, such as a wall. In embodiments the lighting unit 100 can be part of a linear lighting system, such as a cove light system, with the optical facility 130 setting the angle of the light from the cove light system to diffuse smoothly across a wall, providing a color wash on the wall.

[0224] Many types of signal source 124 can be used, for sensing any condition or sending any kind of signal, such as temperature, force, electricity, heat flux, voltage, current, magnetic field, pitch, roll, yaw, acceleration, rotational forces, wind, turbulence, flow, pressure, volume, fluid level, optical properties, luminosity, electromagnetic radiation, radio frequency radiation, sound, acoustic levels, decibels, particulate density, smoke, pollutant density, positron emissions, light levels, color, color temperature, color saturation, infrared radiation, x-ray radiation, ultraviolet radiation, visible spectrum radiation, states, logical states, bits, bytes, words, data, symbols, and many others described herein, described in the documents incorporated by reference herein, and known to those of ordinary skill in the arts.

[0225] FIG. 7 depicts a mechanical actuator 704 for changing the operative effect of an optical facility 702 , in this case a lens 702 that alters the optical path of light from a light system 100 . In this case the shape of the lens 702 is altered by the linear movement of the actuator 704 , which moves a linear element 708 under the control of a processor 102 , which may be integrated with the actuator 704 or may be part of a separate system, such as a remote control. The processor 102 optionally controls the light system 100 as well, so that both the lens and the light system 100 can be controlled simultaneously to provide coordinated changes in the illumination coming from the light system 100 . The processor 102 is also optionally responsive to a signal source 124 , which can be any sensor, such as those described in connection with FIG. 6 . The actuator 704 thus slides the linear element 708 to bend the lens 702 , changing the index of refraction of the light that the lens 702 receives from the lighting unit 100 . The light system 100 can be any light system 100 , such as a linear system, circular system, rectangular array, or other system. The lens 702 can change the beam angle of the light coming from the lighting unit 100 , to produce a variety of lighting effects, such as casting different patterns of light on a wall or object. The actuator 704 can be any type of actuator for providing linear movement, such as an electromechanical element, a screw drive mechanism (such as used in computer printers), a screw drive, or other element for linear movement known to those of ordinary skill in the art.

[0226] FIG. 8 depicts another system for actuating an optical facility to change under the control of a processor. In this case the optical facility is a fluid filled lens 802 , which contains a compressible fluid 808 , such as a gas or liquid. The actuator 804 includes a valve 810 for delivering fluid to the interior chamber of the lens 802 . The actuator 804 is this a pump or similar facility, which may be electromechanical, electrical or mechanical in nature. The actuator 804 pumps fluid 808 into or out of the interior of the lens 802 , causing the lens 802 to change in shape and thus bend light differently as it transmits through the lens 802 . In embodiments the fluid 808 may be selected to have an effect on the light; for example, it may be semi-opaque, so that it produces a glowing effect, or it may have bubbles that refract portions of the light. Any of a wide variety of fluids can be used, such as water, air, fluid polymers and the like. The actuator 804 is optionally controlled by a processor 102 , which may be integrated with it or separate from it and which in turn may optionally be responsive to a signal source 124 . The processor 102 optionally controls the lighting unit 100 , so that coordinated control of the lighting system (e.g., color, intensity, saturation, and color temperature of light) as well as the effect on the light of the optical facility 802 .

[0227] FIG. 9 depicts another optical facility 902 , in this case a fluid-filled lens 902 that operates in response to a pressurizing system 904 , which induces pressure changes in the interior chamber 908 of the lens, such as by increasing the amount of fluid in the chamber 908 or by changing the temperature of the chamber, thus inducing a volume expansion of a gas inside the chamber 908 . The pressurizing system 904 can be controlled by a processor 102 , which can control the light system 100 , optionally under con