LIGHTING DEVICE AND METHOD FOR ADJUSTING PERIODIC CHANGES IN EMULATION OUTPUT.

Abstract

A lighting device, system, and method for emulating sunlight along a daytime or nighttime locus is provided herein. Sunlight is emulated depending on the length of the sun's path relative to a structure containing the lighting device and system. One or more lighting devices can be grouped together to emulate sunlight along the locus, producing different color temperatures throughout the day. All lighting devices within the group produce the same color temperature changes throughout the day.Furthermore, a particular advantage of the preferred modes is the ability to manually change at any time the emulated natural sunlight output of one or more groups of lighting devices and conveniently change the color output more at certain times than at other times simply by triggering a switch on a dimmer associated with a physical or virtual keyboard.

Description

The invention relates to lighting devices comprising light-emitting diodes (LEDs) whose color temperature and / or brightness change automatically during the day or night and, when lighting changes are applied manually, the color temperature can conveniently change based on the time of day. BACKGROUND OF THE INVENTION The following descriptions and examples are provided for background purposes only and are intended to disclose information that is considered to be potentially relevant to the present invention. The fact that the following information constitutes an impact of the prior art on the patentability of the subject matter claimed herein should not necessarily be construed as an admission of such prior art. Lighting fixtures, sometimes called lighting accessories, luminaires, or lamps, include incandescent light fixtures, fluorescent light fixtures, and the increasingly popular light-emitting diode (LED) light fixtures. LEDs offer several advantages over traditional lighting fixtures, such as incandescent and fluorescent light fixtures. Primarily, LED lighting fixtures consume less energy, have a longer lifespan, are constructed with minimal hazardous materials, and can be adjusted in color for different applications. For example, LED lighting fixtures allow for adjusting the chromaticity (e.g., from white to blue to green, etc.) or the color temperature (e.g., from warm white to cool white) to produce different lighting effects. A lighting fixture may include a multi-color LED lighting device, which combines a number of LEDs emitting different colors in a single package. An example of a multi-color LED lighting fixture is one in which two or more different color temperatures of LEDs are combined within the same package to produce white or near-white light. Many different types of white light fixtures are available on the market, some of which combine red, green, and blue (RGB) LEDs, red, green, blue, and yellow (RGBY) LEDs, phosphor-converted white and red (WR) LEDs, RGBW LEDs, and so on.By combining different chromaticity colors of LEDs within the same package, and driving LEDs of different colors coated with or made of different semiconductor materials, and with different drive currents, these lighting devices can mix their chromaticity output and thus generate white or near-white light across a wide range of color temperatures or correlated color temperatures (CCTs), ranging from warm white (e.g., approximately 2600K–3700K) to neutral white (e.g., 3700K–5000K) to cool white (e.g., 5000K–8300K). Some multi-color LED lighting devices also allow the brightness and / or color of the lighting to be adjusted to a particular setpoint.These tunable lighting devices should produce the same color and color delivery index (CRI) when set to a particular chromaticity (or color set point) on a standardized chromaticity diagram. A chromaticity diagram maps the range of colors the human eye can perceive in terms of chromaticity coordinates and spectral wavelengths. The spectral wavelengths of all saturated colors are distributed around the edge of a delineated space (called the gamut of human vision), which encompasses all hues perceived by the human eye. The curved edge of the gamut is called the spectral locus and corresponds to monochromatic light, with each point representing a pure hue of a single wavelength. The straight edge at the bottom of the gamut is called the purple line. These colors, although at the edge of the gamut, have no counterpart in monochromatic light. Less saturated colors appear in the interior of the figure, with white and near-white near the center. In the CIE 1931 chromaticity diagram shown in Figure 1, colors within the gamut of human vision are mapped in terms of chromaticity coordinates (x,y). For example, a red LED (R) with a peak wavelength of 625 nm might have a chromaticity coordinate of (0.69, 0.31), a green LED (G) with a peak wavelength of 528 nm might have a chromaticity coordinate of (0.18, 0.73), and a blue LED (B) with a peak wavelength of 460 nm might have a chromaticity coordinate of (0.14, 0.04). The chromaticity coordinates (i.e., color points) lying along the blackbody locus obey Planck's equation E(A)=AA'5 / (e <B / 0-i). Los puntos de color que yacen en o cerca del locus de cuerpo negro proporcionan un rango de luz blanca o casi blanca con temperaturas de color que varían entre aproximadamente 2500K y 10,000K. Estas temperaturas de color típicamente se logran mezclando luz de dos o más LEDs de diferente color.For example, the light emitted from an RGB LED can be mixed to produce a substantially white light with a color temperature in the range of approximately 2500K to approximately 5000K. Although a lighting device is typically configured to produce a range of white or near-white color temperatures accommodated along the blackbody curve (e.g., approximately 2500K to 5000K), some lighting devices can be configured to produce any color within the color gamut triangle formed by the individual LEDs (e.g., RGB). At least part of blackbody locus 12 is sometimes referred to as the daytime locus corresponding to the Kelvin scale of daytime color temperatures. For example, as shown in Figure 2, several bounding boxes 14a, 14b, 14c, and 14d are shown illustrating color temperatures that aim to emulate daytime sunlight. For example, 14a, 14b, 14c, and 14d are chromaticity regions along the daytime locus of blackbody locus 12 (shown in dashed lines) corresponding to target Kelvin color temperatures of 6000K, 4000K, 3000K, and 2300K, respectively.For example, daytime locus color temperatures of 6000K can emulate the blue sky at midday, 4000K can emulate a less blue mix with the yellow of an overcast sky, 3000K can emulate a mix of predominant yellow with some red from the morning sky, and 2300K can emulate the predominant red with some yellow of the sky at sunrise, similar to the differences between the color temperatures of natural white, cool white, and warm white. Some lighting devices allow color temperatures to be modified by altering the ratio of the drive currents supplied to individual LED strings. The drive currents, and specifically the ratio of drive currents, supplied to LED strings of different colors can be modified either by adjusting the drive current levels (in current dimming) or the duty cycle (in PWM dimming) supplied to one or more of the emitting LED strings. For example, a lighting device comprising RGB LED strings can be configured to produce a warm white color temperature by increasing the drive current supplied to the red LED string and decreasing the drive currents supplied to the blue and / or green LED string. The color delivery index (ORI) defines the overall color appearance or color, and ORI can be defined by luminous flux (i.e., lumen output or brightness) and chromaticity. Brightness and chromaticity, or when combined, color temperature, can often form the target settings, which change due to variations in drive current, temperature, and over time as LEDs wear out. In some devices, the drive current supplied to one or more of the emitting LEDs can be adjusted to change the brightness level and / or color temperature setting of the lighting fixture. For example, the drive currents supplied to all LED strings can be increased to increase the lumen output or brightness of the lighting fixture.In another example, as noted earlier, the color temperature setting of the lighting device can be changed by altering the ratio of drive currents supplied to the LED strings. As noted earlier, a lighting device comprising RGB LEDs can be configured to produce a "warmer" white light by increasing the drive current supplied to the red LED string and decreasing the drive currents supplied to the blue and / or green LED string. There is a need for a lighting device capable of producing a different color or color appearance, defined by its brightness and chromaticity, throughout the day, including evening and nighttime hours. It would be desirable to emulate a daytime setting, extending into the night, of one or more lighting devices configured in interior spaces of a structure. Periodic changes to the brightness, as well as the chromaticity that determines the color temperature of one or more groups of lighting devices within one or more rooms, are required based on timing signals sent periodically throughout the day.The desired timing signals can be sent from a timer away from one or more groups of lighting devices to dynamically change color temperatures in order to track, or correspond with, emulated color temperatures external to the structure, and specific to outdoor sunlight or possible lack thereof. There is also a need for a lighting system and method that does not rely on sensor outputs to periodically change the color temperature output from a single lighting device or one or more groups of lighting devices. Dynamic changes in emulated color temperatures are applied selectively without the use of a sensor, but instead through the use of time-of-day signals applied on a room-by-room basis. This proves convenient and applicable to enhanced lighting systems that do not rely on, and cannot rely on, sensor outputs to periodically change the color temperature output.Furthermore, it is desirable that whenever a task is required involving a change in the color temperature output of one or more lighting devices, the brightness can be conveniently adjusted manually to cancel the emulated sunlight output, or the lack thereof, of color temperatures produced by the LEDs. Similar to a timer designed to produce daylight hours, output at regular periodic times, and corresponding color temperature changes in response to those daylight hours, the desired lighting system can alter the dynamic and automatic emulated sunlight output by manually changing the brightness of all lighting devices within a group to produce different changes in color temperature output depending on the time of day at which the manual adjustment occurs.Therefore, it is advisable to manually adjust color temperatures according to the time of day, and possibly more so during certain times than others. For example, when the emulated sunlight output mimics a higher color temperature near midday, manually adjusting the brightness at that time will not substantially affect the high color temperature required to maintain a more realistic midday sunlight emulation. However, it is advisable to manually adjust the lower color temperature outputs during sunrise and sunset more at these times than at midday, even though the brightness changes by the same amount as at midday.Therefore, it is desirable to leverage the relationship between color temperature as a function of time of day and brightness to achieve dimming (or dimming reversal), resulting in daytime emulation within a structure that is more consistent with the actual sunlight outside. Emulation and manual override should ideally be applied to different groups of lighting fixtures within the structure. For example, automatic emulation within a group of lighting fixtures in a bedroom should differ from that in a kitchen, and manual override in each room should also vary due to the different functions required in those rooms. BRIEF DESCRIPTION OF THE INVENTION The following description provides various modes of a lighting device, system, and method for dynamically and automatically controlling changes in color temperature during the day or night, and manually canceling the automatic color temperature change. Manual cancellation of the dimming for the task can occur at any time of day, and ideally, the color temperature change resulting from a manual adjustment to the automatically changing color temperature (either increasing or decreasing the color temperature depending on the desired task) can effectively and conveniently maintain a more accurate emulation of the actual sunlight changes that occur outdoors as a function of the time of day or night. According to one embodiment, a lighting device is provided comprising a plurality of LED strings, where each string can be configured to produce illumination for the lighting device at a chromaticity consistent with a chromaticity setting. For example, each string can be one of the primary chromaticity colors, such as red, green, or blue. In addition, a string can also have a chromaticity consistent with a white chromaticity setting. The lighting device can also comprise a drive circuit coupled to the plurality of LED strings. The drive circuit is configured to generate a drive current for each of the strings, and based on the drive current supplied to those strings, the drive current can automatically change a color temperature output of the lighting device as a function of the time of day.For example, if the ratio of drive currents to LED strings is modified at periodic times, that modification can occur automatically based on the time outputs of a timer, for example. Automatic color temperature adjustment does not involve triggering a switch, such as a slider, on a remote controller's user interface. Unlike manual override, which involves changing the intensity value sent from a remote controller to an interface or a dimmer to a controller, automatic color temperature adjustment relies on pre-existing parameters or setpoints stored in the memory of one or more lighting fixtures. These settings are accessed when the fixture(s) receive time-of-day signals from the remote controller.A manual cancellation must involve the user pressing a trigger on a user interface, whereas automatic changes to color temperature occur when the appropriate time-of-day signal is sent periodically and automatically without any user pressing a trigger. The lighting device may further comprise a control module coupled to the actuator circuit to send a brightness value resulting from a dimming function for a specific task. This brightness value is sent to each of the plurality of LED strings. The control module may include an interface coupled to receive an intensity value from, for example, a remote controller located at a distance from the lighting device, and specifically the control module may include a controller within the lighting device. A storage medium may include a first nonlinear mapping of the intensity value received from the remote controller to the brightness value sent to the LED strings. The storage medium may also include a second mapping of the color temperature as a function of the time of day.The control module may also include the controller within the lighting device. This controller is designed to receive a change in intensity value from the interface and retrieve the first and second mappings from the storage medium to produce a change in color temperature during the first hour of the day compared to the second hour. In one mode, the change in intensity value can decrease the color temperature during the day as part of the dimming function. Depending on the task, however, the change in intensity value can increase the color temperature if a dimming reversal is required, for example, on cloudy days when a higher temperature is needed for reading.Also, the intensity value can be increased if the current emulated output is at night and a user wishes to increase the color temperature in case he / she wakes up in his / her bed, for example. The user's movement of the remote controller's trigger correspondingly changes the intensity value sent to the control module of each lighting device within a group of lighting devices in a room of a building, for example. As the intensity is increased or decreased, task lighting can be controlled manually or on a room-by-room basis. Furthermore, manual override applied on a room-by-room basis cancels automatic changes in the color temperature output, also applied on a room-by-room basis.For example, a single trigger on a remote controller manually cancels an entire group of automatic color temperature output changes by the lighting fixture using an enhanced discovery and recognition process for group participation. The change in intensity can correspond to either a fixed or variable change in the brightness applied to the LED strings. A fixed change in brightness might produce a greater change in the color temperature output of the LED strings during the first hour of the day than during the second hour, while a variable change in brightness might produce the same change in color temperature output during the first hour of the day as during the second hour.According to the first method, the color temperature can change more during the first hour of the day than during the second hour of the day even when the luminosity output of the LED strings remains constant during the day but has changed by the same amount during the day or, according to the second method, the color temperature can change by the same amount during the first hour of the day as that of the second hour of the day even when the luminosity output of the LED strings changes during the day but has changed by the same amount. Each of the plurality of LED strings can produce a spectral wavelength range that differs from the others. The actuator current to each of the plurality of LED strings is applied as a ratio between the plurality of LED strings, automatically changing according to the time of day. The dynamic and automatic color temperature change functionality only ends when the interface receives an intensity value. The interface that receives the intensity value is one that, during a lighting task—either dimming or dimming reversal, for example, a user's manual cancel trigger via a remote controller—temporarily stops the dynamic and automatic color temperature changes based on the time of day.Alternatively, dynamic and automatic changes in color temperature can continue, albeit at a dimmed or reversed level. For example, when the next time-of-day signal from a timer triggers the next color temperature within the automatically changing color temperature display, the resulting color temperature may be higher or lower than what would normally occur from the display. Manual override occurs when a user presses a button or slider on either the remote controller or a mains-connected AC dimmer comprising a bidirectional triode thyristor (triac). Triggering the button or slider on the remote controller or triac, for example, can cause the button or slider position to be sent as an intensity value output from the remote controller or dimmer to the interface.Canceling manual dimming will cause a change in the brightness output from the multiple LED strings. Canceling manual dimming and the resulting change in brightness output will affect the LEDs' output color temperatures differently depending on the time of day the user activates the trigger (e.g., button or slider). If the color temperatures emitted from the LED strings dynamically change automatically (yi L / nLn / zznz / E / YiAi), for example, from 2300 Kelvin to 6000 Kelvin from sunrise to midday, manual task lighting can be canceled by dimming the output. Manual dimming in the morning will have a greater effect on reducing the color temperature than dimming at midday. Even if the degree of dimming is the same, the reduction in color temperature through task dimming is significantly greater in the morning than at midday. This benefit is key because a user within the building would prefer to maintain the higher color temperatures associated with midday when dimming for a task to be performed in that room.However, a user might also prefer to achieve a greater reduction in color temperature during, for example, the morning or evening hours because, during those times, color temperatures are already approaching the warm white color temperature spectrum, and further dimming for a task would not adversely affect the user's perception of the daylight emulation of sunlight outside, which is already at the lower color temperature locus. Historically, incandescent lights, to which users are accustomed, are around 2700K and will drop as low as 1500K when dimmed. However, high color temperature lighting devices, such as LED or fluorescent lights, do not significantly change color temperature when dimmed.Therefore, the purpose of this for dimming LEDs more in the morning and evening is generally contrary to the operation of conventional LED lighting, although desirably it is achieved through the present manual cancellation which will also maintain the lower conventionally desired LED dimming when higher color temperatures are implemented. According to one embodiment, the drive current for each of the plurality of LED strings is preferred to change automatically as a function of the time of day to adjust the LEDs' color temperature output, thus emulating natural daylight from sunrise to sunset. According to a further embodiment, although the drive current for each of the plurality of LED strings changes automatically based on a timer output correlated with the sun's position, the interface allows for either wired or wireless communication from a timer within a remote controller located away from the lighting fixture. This remote controller also allows a user to trigger a switch and change the intensity value sent to the interface.The dimming or dimming reverse trigger slider can be set on the remote controller or on a triac-based dimmer located away from the lighting fixture and connected to the AC mains. Activating the trigger not only changes the intensity value but also correspondingly changes the brightness by the same amount across all LEDs within one or more groups of lighting fixtures controlled by the trigger. However, depending on the time of day, this change in brightness resulting from the intensity change is more pronounced when the LEDs would normally produce a lower color temperature than when they would produce a higher one.The benefit of the different color temperature effects, even with the same change in brightness, stems from the human perception of emulated sunlight, i L / nLn / zznz / E / YiAi, as previously mentioned. This is motivated by the user's desire to maintain a higher color temperature during peak sunlight hours compared to off-peak hours when they wish to lower the color temperature during manual dimming. This adjustment occurs whenever a user wants to dim from a higher to a lower brightness to perform certain tasks, maintaining a higher color temperature during peak sunlight hours and more substantially reducing the color temperature during off-peak hours. According to yet another embodiment, a lighting system is provided. The lighting system may comprise a plurality of LEDs configured to produce a plurality of color temperatures along the blackbody curve. A timer may also be provided to produce a plurality of daylight hours comprising a first hour of the day and a second hour of the day. A drive circuit may be coupled between the timer and the plurality of LEDs to receive the plurality of daylight hours and allocate a drive current to the plurality of LEDs to produce a first color temperature during a first hour of the day and a second color temperature during a second hour of the day.The actuator circuit automatically and dynamically produces the first and second color temperatures depending on when the timer generates the first and second hour of the day signals. However, the dynamic and automatic production of the first and second color temperatures can be overridden by the user pressing the trigger. A control module, specifically an interface coupled to the control module, can receive the intensity value from the remote controller or dimmer and send a corresponding brightness value to each of the multiple LEDs. The brightness value is determined based on a first nonlinear mapping of the intensity value. This first nonlinear mapping can be stored on a storage medium, along with the second mapping of the color temperature as a function of the time of day.The storage medium, and specifically the first and second mappings, are used by a controller. When the controller receives a change in intensity value from the remote controller or dimmer, it retrieves the first and second mappings from the storage medium and may produce a greater change in color temperature during the first hour of the day than during the second hour, even though the change in brightness resulting from the intensity value change is the same for both. For example, the timer within the remote controller is preferably any module, circuit, or system that incorporates a clock. The clock preferably changes depending on the Earth's position relative to the structure on which the timer is mounted. The clock can be coupled to any synchronization system, such as a crystal oscillator, or it can receive periodic power, for example, from a satellite or via the internet. Furthermore, the clock can preferably be reset based on the latitude and longitude coordinates of the timer's location, as well as the specific time zone. The timer generates multiple times of day at any interval desired by the user, such as every minute, hour, or several hours. These multiple times of day can then include daytime hours, starting with, for example, 6 am, 7 am, 8 am, etc.If the regular timed intervals are set to be every hour, the timer can produce time-of-day signals only at selected times, such as at sunrise, one hour after sunrise, one hour before sunset, and / or at sunset. In this latter example, the timer can produce signals at relatively short intervals (e.g., 10-minute intervals) over a fixed period (e.g., one hour) to create a fading or rounding effect each time the color temperature changes after sunrise and before sunset. To an observer, the color temperature would then change in a series of increments or decrements, or linearly, to increase or decrease the automatic color temperature change. Like the timer, which is preferably set on the remote controller (i.e., a physical keypad or a wired or wirelessly connected laptop to the group(s) of lighting fixtures), the dimmer connected to the AC mains is also located away from the lighting fixtures. The remote controller or dimmer manually changes the brightness level in a non-linear fashion and, depending on the time of day, changes the color temperature by varying amounts. A change in the intensity setting from the dimmer changes the brightness level equally across all the LEDs, although, depending on the time of day, it changes the color temperature by the same or different amounts. For example, the dimmer might include a trigger that, when activated by the user, changes the color temperature more before 10:00 AM and after 4:00 PM than between 10:00 AM and 4:00 PM.Also, when activated by a user, the movement of the trigger on the dimmer can register a change in the corresponding intensity value and, consequently, the brightness value. The preferred color temperature decreases more before 10:00 AM and after 4:00 PM than between 10:00 AM and 4:00 PM. The color temperature decreases more significantly one or two hours after sunrise and one or two hours before sunset than in the interval between sunrise and sunset. These times are local times relative to the geographical location of the structure containing the lighting fixtures. According to another still preferred embodiment, the plurality of LEDs may comprise a first plurality of LEDs. A second plurality of LEDs may be grouped with the first plurality of LEDs within a room of a structure. Consequently, two or more LED-based lighting devices may be grouped together within a room of a structure. These lighting devices may be a group of projector PAR lighting devices mounted on a ceiling and / or one or more A20 or A19 lighting devices placed in lamps on bedside tables, for example. Regardless of the type of lighting device or its functionality, the lighting devices may be grouped together for control purposes. Typically, however, a group of the lighting devices is configured in close geographical proximity to one another within a room of a structure, for example.Therefore, preferably according to certain configurations, a group of lighting devices can be set to produce the same color temperature across all devices within that group. The color temperature across the grouped lighting devices is established using datasets stored within each device. This dataset content is configured and subsequently stored in the grouped lighting devices (i L / nLn / zznz / E / YiAi) using a remote controller, for example.The remote controller can then not only discover all the lighting fixtures within a structure and subsequently group sets of lighting fixtures, but it can also assign datasets that define the chromaticity and brightness values ​​of each lighting fixture to the group. Later, when the timer triggers a time-based exposure, such as automatic color temperature fade, periodic time-of-day signals are sent to the specific grouped set of lighting fixtures. This will cause all the lighting fixtures within that group to experience an automatic change in color temperature, and possibly also brightness output, throughout the day.Accordingly, the preferred method includes automatically changing the color temperature among the grouped plurality of lighting devices based on different periodic time-of-day signals sent from a timer located away from the grouped plurality of lighting devices to emulate the changing natural light produced by the sun. The preferred method of lighting also involves manually dimming the brightness of the grouped plurality of lighting devices, resulting in a change in color temperature based on a current time-of-day signal sent from the timer. Specifically, if the manual dimming occurs at an earlier time of day (i.e., on the current time-of-day signal for the first hour of the day), the color temperature may change more than if the manual dimming occurs during a later time of day (i.e., on the current time-of-day signal for the second hour of the day).Manual dimming can maintain its canceled status by either ending the automatic color temperature changes or by increasing / decreasing the automatically changing color temperatures until a time limit time elapses, a predetermined time-of-day signal occurs, or possibly the next predetermined time-of-day signal that occurs subsequently. The canceled status can be maintained indefinitely or for a specific predetermined amount of time.Furthermore, manual cancellation, and specifically changes in the intensity of dimming and dimming reversal levels, can occur gradually over multiple steps, linearly, exponentially, or according to any user-defined dimming or reversal gradient, over a fixed or variable amount of time to gradually fade out automatically changing color temperature effects. Details of these, including the aforementioned modes, are further described below. BRIEF DESCRIPTION OF THE FIGURES Other objectives and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the accompanying drawings. Figure 1 is a graph of the CIE 1931 chromaticity diagram illustrating the blackbody curve of color perception or color temperatures, and the range of spectral wavelengths that can be achieved by the lighting device comprising a plurality of LEDs of different colors; Figure 2 is an exemplary color temperature space along the blackbody curve showing four illumination limits of the plurality of LEDs; Figure 3 shows an angular relationship between a structure containing the lighting device / L / nLn / zznz / E / YiAi 1 and the sun, including changes in the path length traveled by daylight during the day; Figure 4 is a graph of the relationship between dominant wavelengths during the day depending on the path length of the sun; Figure 5 shows an arrangement of different colored LEDs within a lighting device, where each of the different colored LEDs can be configured within a string of similar colored LEDs; Figure 6 is an exemplary plan diagram of a structure containing a plurality of lighting devices arranged in one or more groups within one or more rooms of a structure, with corresponding remote controllers also placed throughout one or more rooms within the structure; Figure 7 is an exemplary block diagram of the lighting device comprising a power supply converter, LED driver circuit, control circuit controller, and a plurality of different colored LED strings; Figure 8 is an exemplary block diagram of the LED driver circuit that can be included within the lighting device of Figure 7; Figure 9 is an exemplary GUI of a remote controller of lighting devices, further illustrating the commissioning of physical lighting devices to groups possibly associated with a particular area or room within the structure; Figure 10A is an exemplary GUI of the controller shown in Figure 7, further illustrating the assignment of lighting device groups, for example, to a keyboard button; Figure 10B is an exemplary GUI of the controller shown in Figure 7, further illustrating the assignment of a scene or scene that changes as a function of time (i.e., exposure) to one or more previously assigned groups, e.g., to a keyboard button; Figure 10C is an exemplary GUI of the controller shown in Figure 7, further illustrating the assignment of color and brightness to each scene and the allocation of a time to use each scene in order to formulate an exposure; Figure 11 is a graph of the spectral sensitivity of luminosity to different color wavelengths; Figure 12 is a graph of the brightness at different intensities, such as energy or current, supplied to the lighting device; Figure 13A and Figure 13B are graphs of different color temperatures appearing at different times of the day, and the different effect of changes in brightness on those colors depending on when the brightness changes; Figure 14 is a block diagram of the content (or data sets) stored in the storage medium of the lighting device and the time message sent from the controller to address a different data set depending on the status of the real-time clock within the controller, and automatically change the color output of the lighting device depending on the status or manually change the color output of the lighting device if a different data set is addressed; i L / nLn / zznz / E / YiAi Figure 15 is a graph of color temperature change as a function of both time of day and brightness; Figure 16 is another graph of color temperature change as a function of both time of day and brightness; and Figure 17 is a block diagram of intensity forwarded to a luminosity dimension curve and luminosity forwarded to a color emulation curve to generate a target color temperature whenever the daytime emulation exposure, for example, is changed manually. Although the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will be described herein in detail. However, it should be understood that the drawings and their detailed description are not intended to limit the invention to the particular form disclosed, but rather, the intention is to encompass all modifications, equivalents, and alternatives that fall within the spirit and scope of the present invention as defined by the appended claims. DETAILED DESCRIPTION OF THE INVENTION Among the various advantages of LED-based lighting devices is the fact that LEDs offer diverse opportunities to integrate artificial and natural light, providing useful and healthy illumination through dynamic lighting mechanisms. A particular niche for LED-based lighting devices is the generation of artificial sunlight for a variety of reasons, especially for the treatment of human conditions such as circadian rhythm disorders, stationary phase disorders, shift work disorders, and so on. The mechanism by which many conventional LED-based lighting devices replicate or emulate natural sunlight conditions is through the use of sensors.Sensors can detect sunlight conditions inside a structure and create artificial lighting from the lighting device that attempts to replicate or emulate natural sunlight conditions outside the structure. Unfortunately, sensors have limitations both in technology and in their placement. Therefore, sensors do not always accurately detect external sunlight conditions, and natural sunlight conditions outside cannot always be properly emulated. Therefore, another preferred alternative is to keep track of the time of day and send multiple time-of-day values ​​from a timer to LED-based lighting devices. Instead of using a sensor, with its associated failures, a timer is used, and the emulated sunlight changes based on the time-of-day values ​​sent from the timer. Using timers and time-of-day values ​​is beneficial when circadian rhythms need to be adjusted differently depending on the room in which sunlight is being emulated. Sensors cannot adapt the emulation depending on the room; instead, they detect and provide consistent emulation throughout the structure.Grouping lighting devices on a room-by-room basis and controlling each room separately using different remote controllers and timers associated with different time-of-day values ​​is based on timers, not sensors—an added benefit of not using sensors to control sunlight emulation. Of course, there are acceptable limits to using a timer versus a sensor. A timer changes the time-of-day value sent to the lighting device to update the device's output at regular intervals throughout the day, without regard for whether outside conditions change from what would normally occur at that time of day.For example, a timer on its own cannot detect cloudy, partly cloudy, overcast, hazy, or rainy outdoor conditions unless that timer is coupled to a sensor, and that sensor is preferably located outside the structure and communicatively linked to the timer. Therefore, the timer's ability to transmit multiple time-of-day values, or data, from a remote controller's timer to the lighting devices is limited to the normal sunlight conditions expected during various times of day. While using a timer to simulate sunlight is linked to what are statistically normal sunlight conditions in some cases, it is adapted to the room's orientation and sunlight conditions.The benefit of selectively adapting the emulation depending on the group of lighting devices being controlled and the orientation of the room containing those devices outweighs any benefit of using sensors instead of timers. Individual control and adaptation on a room-by-room basis between groups of lighting devices proves to be a superior control mechanism to sensors on most days of the year. Any deviation between what the timer determines to be normal daylight hours and what is actually occurring outside is an acceptable deviation and does not detract from the sunlight emulation performed by the timer, nor from the benefits of adapting timer control between rooms within the structure.Using only a timer without a sensor is also suitable simply because of the ease of use of a timer compared to the inaccurate and often unreliable readings of sensors used to detect unusual outdoor sunlight conditions. However, if the resulting emulation exposure is unacceptable to a user, the user can always manually change the color temperature output at any time, as described below. According to one approach, sunlight conditions are emulated using a timer that manipulates and updates the emulation of lighting devices based on the calendar day and time of day. This functionality is executed automatically and dynamically throughout the day. The automatic emulation occurs as a dynamically changing exposure that continues automatically without user intervention. Specifically, it continuously changes the color temperature output in response to the time-of-day signals sent by the timer to the lighting devices. The automatic emulation and the automatically changing color temperature occur without the user triggering a shutter release, which is functionally reserved for manual cancellation, not for automatic exposure.Subsequently, depending on the tasks required by a user, or if the user wishes to manually adjust the emulation to be more accurate with respect to what is happening outside the structure, the user can manually change the color temperature output of a lighting device or a specific group of lighting devices either in a single step in response to a user input, gradually in a plurality of rounded steps, or linearly as a function of time. The same reversion in a plurality of rounded steps or linearly as a function of time can occur, returning the output to the automatically and dynamically changing emulation after the task is completed, after a user returns a dimmer to its previous trigger position, or after the next time-of-day sunlight emulation change occurs. Figure 3 illustrates in further detail the daytime locus and spectral characteristics resembling the sunlight shown in Figures 1 and 2, resulting from the changing position of sun 16 relative to, for example, a structure 18 that has one or more lighting devices. As shown in Figure 3, the angular relationship between sun 16 and structure 18 changes during the day, and this angular relationship is often referred to as the zenith angle, θz. As sun 16 moves from a suspended position to a nearly horizontal position relative to the Earth's surface 20, the path length (PL) increases from PLi to PL4. Importantly, the spectral distribution of sunlight, specifically the spectral irradiance of sunlight, changes with the PL.As shown in Figure 4, shorter wavelengths can be more sensitive and produce greater spectral irradiation at shorter path lengths (PLs) than longer wavelengths. A combination of Figures 3 and 4 illustrates that as the sun 16 is directly over structure 18, the shorter path length (PL1) produces a greater amount of lower-wavelength chromaticity spectrum, and as the sun 16 approaches the horizon, the longer path length (PL4) shows a predominance of longer-wavelength spectral irradiation. At PL1, the natural sunlight condition is typically more of a natural sunlight or cool white color temperature, with a preponderance of blue versus red and yellow.Conversely, as the path length increases to PL4, the color temperature approaches the warm white associated with incandescent or halogen lighting, with a predominance of red and yellow versus blue. To emulate changes in natural sunlight conditions within an artificial lighting system, such as the present lighting fixture(s), the lighting fixture(s) must change its color temperature output throughout the day, based, for example, on changing path lengths (PLs). Figure 5 partially illustrates a white LED lighting device 24. The lighting device produces white illumination by comprising, for example, a plurality of white LED semiconductor devices 26, a plurality of yellow-green semiconductor devices 28, a plurality of red LED semiconductor devices 30, and, if the lighting device 24 is an RGB-based lighting device, a blue LED semiconductor device 32. The red, green, blue, and white semiconductor devices are defined in a particular chromaticity region of the chromaticity space, which includes a target chromaticity region of combined light emitted by the red, green, and white light emitters. The RGB system can produce white light of a particular color temperature depending on the mixture of the various red, green, and blue chromaticity regions, for example.Red, green, blue, and white semiconductor devices are made from a variety of organic or inorganic semiconductor materials, each producing a different chromaticity or wavelength output. Some of the red semiconductor devices... Green, blue, or white LEDs can be encapsulated with a coating to produce the desired wavelength or chromaticity output. For example, a white LED semiconductor device can include a blue LED semiconductor device coated with phosphor. Furthermore, by independently dimming each of three or four RGB or RGBW LEDs (or LED strings), the lighting device can produce a wide color gamut, with a color temperature along the blackbody curve and, according to the desired output, across a daytime locus. Figure 6 illustrates an example of a structure 36 containing a plurality of lighting devices 38. The lighting devices 38 are sometimes referred to interchangeably simply as lamps, fixtures, or luminaires. A residence 36 may have numerous rooms, such as bedrooms, living rooms, etc. Preferably, each lighting device comprises at least one LED, or more preferably, several strings of LEDs, where each string can produce a corresponding color within a chromaticity region. The lighting devices 38 may include PAR lighting devices shown as spotlights 38a within, for example, a living room, and other PAR lighting devices 38c as spotlights within, for example, a bedroom. For example, the living room may have four spotlights labeled 38a, while the bedroom may have three spotlights labeled 38c.Next to the armchair inside the room, for example, there are tables on which the A20, 38b lighting devices are configured, for example. Ideally, each lighting device includes a communication interface for a first communication protocol, the communication protocol being a wireless communication protocol used by all lighting devices within a residence, for example. A popular first communication protocol might be WPAN using IEEE 802.15.4 and / or any protocol based on it, such as ZigBee. The lighting devices can then communicate wirelessly with each other, if desired. In addition to the wirelessly interconnected lighting devices, remote controllers can also be interconnected either wirelessly or via cable. The remote controllers shown in Figure 6 could be physical keypads associated, for example, with the living room and bedroom, respectively.As will be discussed later, physical keyboards can be replaced by virtual keyboards and assigned, for example, to a mobile phone and specifically to the GUI displayed on the mobile phone or mobile computer. Remote controllers can then be a physical keyboard connected via cable or wirelessly to the group or groups of physical lighting devices controlled by the physical keyboard, or they can be a handheld computer connected wirelessly to the group or groups of lighting devices controlled by a virtual keyboard displayed in a GUI on the wireless handheld device. The virtual keyboard displayed in the mobile device's GUI can appear identical to physical keyboards, with virtual triggers (i.e., buttons, sliders, etc.) similar to the actual triggers on physical keyboards.Physical keyboards can communicate with their corresponding lighting devices either via cable or wirelessly, while the virtual keyboard displayed in a mobile device's GUI can communicate using a wireless communication protocol such as WPAN or ZigBee. In addition to the first communication protocol used by the physical lamp in the lighting devices 38 and the physical keyboards 40, a second communication protocol is linked to the first via a bridge 42 that can be placed near the lighting device 36. This bridge can then enable a second communication protocol, such as Ethernet, Wi-Fi, Bluetooth, etc., for communication between, for example, a mobile phone and the lighting devices 38. Figure 7 illustrates an exemplary block diagram of the lighting device 38, according to one embodiment of the invention. The lighting device illustrated in Figure 7 provides an example of the hardware and / or software that can be used to implement a method for emulating natural sunlight both dynamically and automatically, and subsequently manually canceling that emulation when one or more lighting tasks are required. Manual cancellation may be required to perform a temporary task or to more accurately emulate the current outdoor sunlight conditions, for example, changing from a sunny, cloudless outdoor sunlight condition to a cloudy or rainy condition. The physical lighting device 38 comprises a plurality of emissory LEDs 40, and in this example comprises four strings of any number of LEDs connected in series. Each string may have two to four LEDs of the same color, which are coupled in series and configured to receive the same drive current. In one example, the emissory LEDs 40 may include a string of red LEDs, a string of green LEDs, a string of blue LEDs, and a string of white or yellow LEDs. However, the preferred embodiments are not limited to any particular number of LED strings, any particular number of LEDs within each string, or any particular color or combination of LED colors. In some embodiments, the emissory LEDs 40 may be mounted on a substrate and encapsulated within a primary optical structure of an emitter module, possibly together with one or more photoelectric sensors. In addition to the emitting LEDs 40, the lighting device 38 includes various hardware and software components to power the lighting device and control the light emitted from one or more emitter modules. In the configuration shown in Figure 7, the lighting device 38 is connected to the AC mains power supply 42 and includes an AC / DC converter 44 to convert the AC mains voltage (e.g., 120V or 240V) into a DC voltage (Vo). The DC voltage (e.g., 15V) is supplied to the LED driver circuits 46 to produce the drive currents, which are then supplied to the emitting LEDs 40 to produce illumination. In the configuration of Figure 7, a DC / DC converter 48 is included to convert the DC voltage (Vdc) to a lower voltage Vl (e.g., 3V).3 V), which is used to power the lower voltage circuit of the lighting device, such as the phase-locked loop (PLL) 50, the interface 52, and the control circuit 54. In other embodiments, the lighting device 38 may be powered by the DC voltage source (e.g., a battery) instead of the AC mains 42. In such embodiments, the lighting device may be coupled to the DC voltage source and may or may not include a DC / DC converter instead of the AC / DC converter 44. Additional timing circuitry may be required to provide timing and synchronization signals to the control drive circuits. In the illustrated configuration, the PLL 50 is integrated within the lighting device 38 to provide timing and synchronization signals. The PLL 50 can be locked to the AC mains frequency and can produce a high-speed clock (CLK) signal and a synchronization (SYNC) signal. The CLK signal provides timing signals for the control circuit 54 and LED driver circuits 46. In one example, the CLK signal frequency is in the tens of MHz range (e.g., 23 MHz) and is precisely synchronized to the AC mains frequency and phase. The SYNC signal is used by the control circuit 54 to generate the timing signals used to control the LED driver circuits 46. In one example, the SYNC signal frequency is equal to the AC mains frequency (e.g., 50 or 60 Hz) and is also precisely phase-aligned with the AC mains. In some embodiments, interface 52 may be included within the lighting device 38 to receive data sets or content from an external calibration tool during device manufacturing, or during provisioning or commissioning of the lighting device or group of lighting devices. The data sets or content received through interface 52 may be stored in a mapping table within the storage medium 56 of the control circuit 54, for example.Examples of the data set or content that can be received through interface 52 include, but are not limited to, luminous flux (i.e., brightness values), intensity, wavelength, chromaticity of the light emitted by each string of LEDs (i.e., when the mixing forms the color temperature) and, more specifically, as will be described in further detail below, (a) a mapping of brightness values ​​to intensity values, and (b) color temperature for brightness values ​​and time-of-day values. Interface 52 is not limited to receiving data sets or content during the provisioning or commissioning of the lighting device or group of lighting devices. Interface 54 can also be used to receive commands, for example, from a remote controller 64. Commands can also be sent from dimmer 52 to the control circuit (controller) 54. Dimmer 62 can be coupled to the AC mains, as shown, similar to a triac, to allow manual operation of the dimmer by a user. The triac in dimmer 62 changes the RMS phase-cutoff voltage in the AC mains and forwards the corresponding intensity value to the lighting device. By actuating a trigger button or slider on the remote controller 64 or dimmer 62, a dimming or dimming reversal command in the form of an intensity value can be sent to the actuator circuits 46.As opposed to triggering a switch on the dimmer 52, a user can trigger a switch (i.e., button or slider) on a remote controller's user interface, such as a physical keyboard, or on a graphical user interface of a portable computer, such as a smartphone or laptop, to allow the dimming or dimming inversion command to be sent from the remote controller 64 through the interface 52, either via cable or wirelessly. A decrease in intensity value as a result of dimming (or an increase in intensity value as a result of dimming inversion), whether through the dimmer 62 or remote controller 64, will cause a decrease / increase in brightness due to the mapping table stored on the medium 56 and retrieved by the control circuit driver 54.For example, commands can be communicated to the lighting device 38 via the dimmer 62 or remote controller 64 and interface 52 to turn the lighting device on / off, to control the brightness level, and, as described below, to manually and temporarily cancel the color temperature sunlight emulation exposure (day or night) when a task is running or when a color temperature emulation more accurate to the actual sunlight condition is being run, e.g., a cloudy, rainy, or overcast condition outdoors. Interface 52 is not limited to receiving data sets or content during the provisioning or commissioning of the lighting device or group of lighting devices. Interface 54 can also be used to receive commands, for example, from a remote controller 64. Commands can also be sent from dimmer 62 to the control circuit (controller) 54. Dimmer 62 can be coupled to the AC mains, as shown, similar to a triac, to allow manual operation of the dimmer by a user. The triac in dimmer 62 changes the RMS phase-cutoff voltage in the AC mains and forwards the corresponding intensity value derived from this to the lighting device. By actuating a trigger button or slider on the remote controller 64 or dimmer 62, a dimming or dimming reversal command in the form of an intensity value can be sent to the actuator circuits 46.As opposed to triggering a switch on the dimmer 62, a user can trigger a switch (i.e., button or slider) on a remote controller's user interface, such as a physical keyboard, or on a graphical user interface of a portable computer, such as a smartphone or laptop, to allow the dimming or dimming inversion command to be sent from the remote controller 64 through interface 52, either via cable or wirelessly. A decrease in intensity value as a result of dimming (or an increase in intensity value as a result of dimming inversion), whether through the dimmer 62 or remote controller 64, will cause a decrease / increase in brightness due to the mapping table stored on the medium 56 and retrieved by the control circuit driver 54.For example, commands can be communicated to the lighting device 38 via the dimmer 62 or remote controller 64 and interface 52 to turn the lighting device on / off, to control the brightness level, and, as described below, to manually and temporarily cancel the color temperature sunlight emulation exposure (day or night) when a task is running or when a color temperature emulation more accurate to the actual sunlight condition is running, e.g., a cloudy, rainy, or overcast condition outdoors. According to a preferred embodiment, interface 52 is coupled to receive control signals from a remote controller 64 and specifically from a user actuating a trigger on the remote controller 64 to alter an automatically changing lighting display among one or more lighting devices 38. With respect to the automatically changing lighting display, the remote controller 64 may include a timer that sends a plurality of time-of-day signals to the control circuit controller 54 via interface 52. For example, if the remote controller 64 comprises a physical keypad 40 having a real-time clock thereon, the real-time clock, depending on the calendar day and time of day, periodically sends a time-of-day signal from among a plurality of time-of-day signals. The time-of-day signal is unique to the calendar day and time of day recorded and emitted by the timer.If time-of-day signals are sent, for example, every hour, only the time-of-day signal specific to that current hour is sent from among the plurality of i L / nLn / zznz / E / YiAi time-of-day signals, each corresponding to a different hour. Using timing signals received from PLL 50 and control signals from interface 52 (for example, a periodic set of time-of-day signals sent from a remote timer to create an exposure that has a change in daylight emulation as a function of the time of day, and a dimmer to execute a dimming function to change intensity values ​​to a desired brightness level), the control circuit driver 54 calculates, based on brightness and color temperature, mappings as a function of the brightness and time of day stored in medium 56, and produces values ​​indicating a desired drive current to be supplied to each of the LED strings 40. This information can be communicated from the control circuit driver 54 to the LED drive circuits 40 over a serial bus that conforms to a standard, such as SPI or PC.In addition, the control circuit 54 can provide a latching signal that instructs the LED driver circuits 46 to simultaneously change the drive currents supplied to each of the LED strings 40 to avoid color and brightness artifacts. In some embodiments, the controller 54 can be configured to determine the respective drive currents necessary to achieve a desired luminous flux and / or a desired chromaticity for the lighting device in accordance with one or more of the compensation methods described in United States Patent Application Serial Numbers 14 / 314,530 issued December 31, 2015 as United States Publication Number 2015 / 0382422 A1; 14 / 314,580 issued July 12, 2016 as United States Patent Number 9,392,663; and 14 / 471,081 issued March 3, 2016 as United States Publication Number 2016 / 0066384 A1, which are commonly assigned and incorporated herein in their entirety.In a preferred embodiment, the control circuit controller 54 can further be configured to adjust the drive currents supplied to the emission LEDs 40, so as not to exceed a maximum safe current level or a maximum safe energy level attributed to one or more power converters of the lighting device 38 at an operating temperature present as determined by the temperature sensor 58. As shown in Figure 7, the temperature sensor 58 can be incorporated into the lighting device 38 to measure the device's operating temperature. In some embodiments, the temperature sensor 58 can be a thermistor thermally coupled to a circuit board or chip comprising one or more of the components shown in Figure 7. For example, the temperature sensor 58 can be coupled to a circuit board comprising the AC / DC converter 44, the DC / DC converter 48, the PLL 50, and the interface 52. In another example, the temperature sensor 58 can be thermally coupled to the chip comprising the LED driver circuits 46 and the emissive LED strings 40.In other configurations, the temperature sensor 58 can be an LED, which is used as a temperature sensor and as an optical sensor to measure ambient light conditions or emit characteristics of the LED strings 40. The temperature measured by the sensor 58 is supplied to the controller 54 to adjust the drive currents. In some embodiments, the control circuit controller 54 can determine the respective drive currents by executing program instructions stored within the storage medium 56. In one embodiment, the storage medium 56 that stores the first and second i L / nLn / zznz / E / YiAi mappings can be a non-volatile memory, and can be configured to store the program instructions together with a calibration value table, as described, for example, in U.S. Patent Application Serial Numbers 14 / 314,451 issued December 31, 2015 as U.S. Publication Number 2015 / 0377699 A1, and 14 / 471,057 issued December 31, 2015 as U.S. Patent Number 9,392,660, which are commonly assigned and incorporated herein in their entirety.Alternatively, the control circuit controller 54 may include combinational logic to determine the desired drive currents, and the storage medium 56 may only be used to store the intensity mapping tables as a function of luminance values ​​and color temperatures as a function of luminance values ​​and time of day. In general, the LED drive circuits 46 may include a number (N) of drive blocks 68 equal to the number of emissory LED strings 40 included within the lighting device 38. In one exemplary embodiment, the LED drive circuits 46 comprise four drive blocks 68, each configured to produce illumination from a different string of the emissory LED strings 40. In some embodiments, the LED drive circuits 46 may include circuits for measuring ambient temperatures, measuring forward voltages and photocurrents from photodetectors and / or emitters, and adjusting the LED drive currents. Each drive block 68 receives data indicating a desired drive current from the control circuit 54, along with a latching signal indicating when the drive block 68 should change the drive current. Figure 8 is an exemplary block diagram of the LED driver circuits 46, according to one embodiment of the invention. In the exemplary embodiment of Figure 8, the LED driver circuits 46 include four driver blocks 68, each block comprising a DC / DC converter 72, a current source 74, and an LC filter 76 to generate the operating drive currents (Idrv) supplied to a connected string of emitting LEDs 40a to produce illumination, and the relatively small drive currents (Idrv) used to obtain the forward emitter voltage (Vfe) measurements. In some embodiments, the DC / DC converter 72 can convert the DC voltage (Vcd) into a pulse-width modulated (PWM) voltage output (Vdr) when the controller 80 drives the Out_En signal high. This PWM voltage signal (Vdr) is filtered by the LC 76 filter to produce a forward voltage at the anode of the connected LED string 40a.The cathode of the LED string is connected to current source 74, which pushes a fixed drive current (Idrv) equal to the value provided by the Emitter Current signal through the LED string 40a when the LED_On signal is high. The Ve signal from current source 74 provides feedback to the DC / DC converter 72 to emit the appropriate duty cycle and minimize the voltage drop across current source 74. As shown in Figure 8, each driver block 30 can also include a differential amplifier 78 to measure the forward voltage drop (Vfe) across the connected string of emissive LEDs 26a. When Vfe is measured, the DC / DC converter 32 is switched off, and the current source 74 is set to draw a relatively small drive current (e.g., approximately 1 mA) through the connected string of emissive LEDs 40a. The forward voltage drop (Vfe) produced across the LED string 40a by this current is measured by the differential amplifier 78, which outputs a signal equal to Vfe. The forward voltage (Vfe) is converted into a digital signal i L / nLn / zznz / E / YiAi by the analog-to-digital converter (ADC) 42 and supplied to the driver 80.The second controller 80 determines when to take forward voltage measurements and produces the signals OUT On, Emitter Current and LED_On, which are supplied to each of the actuator blocks 68. The LED driver circuit 46 is not limited to the configuration shown in Figure 8. In some configurations, each LED driver block 68 may include additional circuitry for measuring photocurrents, which are induced through one or more of the emitting LED strings 40 when these strings are configured to detect incident light (e.g., ambient light or light emitted from other emitting LEDs). In some configurations, the LED driver circuit 46 may additionally include one or more receiver blocks (not shown) for measuring the forward voltages and / or photocurrents induced through one or more photodetectors, which may also be included within the emitter module. In some configurations, the LED driver circuit 46 may include a temperature sensor for measuring the driver circuit temperature and a multiplexer for multiplexing the emitter forward voltages (Vfe) and measured temperatures to the ADC 82.Exemplary modalities of said actuating circuit are described in the previously mentioned co-pending applications. The DC / DC converter 48 and the DC / DC converters 72 can substantially include any type of DC / DC power converter, including, but not limited to, buck converters, boost converters, buck-boost converters, Cuk converters, single-ended primary inductor (SEPIC) converters, or reverse converters. The AC / DC converter 44 can likewise substantially include any type of AC / DC power converter, including, but not limited to, buck converters, boost converters, buck-boost converters, Cuk converters, single-ended primary inductor (SEPIC) converters, or reverse converters.Each of these power converters typically comprises a number of inductors (or transformers) to store energy received from an input voltage source, a number of capacitors to supply energy to a load, and a switch to control the energy transfer between the input voltage source and the load. The output voltage supplied to the load by the power converter can be higher or lower than the input voltage source, depending on the type of power converter used. According to a preferred embodiment, the AC / DC converter 44 comprises a reverse converter, while the DC / DC converter 48 and the DC / DC converters 72 comprise step-down converters. The AC / DC converter 44 converts AC mains power (e.g., 120V or 240V) into a substantially lower DC voltage Vcd (e.g., 15V), which is supplied to the step-down converters 48 / 72. The step-down converters 48 / 72 reduce the DC output voltage of the AC / DC converter 44 to lower voltages, which are used to power the low-voltage circuits and provide drive currents to the LED strings 40. In some modes, the brightness level can be adjusted from the dimmer 62 or remote controller 64 substantially continuously between a minimum level (e.g., 0% brightness) and a maximum level (e.g., 100% brightness), or vice versa. The adjustment can be linear, but in most cases, due to the difference in the slider adjustment on the dimmer and remote controller 64 relative to the brightness output, the adjustment is nonlinear and is more on a logarithmic scale, as shown and described in Figure 12. Specifically, the movement of a trigger position i (movement of a slider, amount of time a button is pressed, or whether one or multiple buttons are pressed) translates into an intensity value. The trigger position may correspond to an intensity value, but the trigger position / status or intensity value is non-linear with respect to the light level.Therefore, triggering the light does not translate to exact one-to-one changes in brightness level. Nonlinear mapping is required. By defining the brightness level as a 16-bit variable, scaling can be easily achieved. In other modes, the brightness level can be adjusted between a limited number of predefined steps, where each step corresponds to a percentage change in brightness (e.g., maximum brightness of 0%, 25%, 50%, 75%, or 100%) or a decibel change (e.g., + / -1dB) in lumen output. Figure 9 illustrates an example in which the 38 physical lighting devices are grouped based on their location and function. The mechanism for providing the grouping, as well as the function of the lighting devices, will be discussed below when the grouping mechanism and the scene / exposure assignment mechanism are described. However, as shown in Figure 9, a location such as the bedroom can have a group of 38 lighting devices, and associated with that group of 38 lighting devices is a particular scene or exposure. Because each of the 38 lighting devices has one or more LEDs, the RGB of the plurality of LEDs can be adapted to any color, brightness, or visual effect desired by the user by setting a time-changing scene or exposure within the grouped lighting devices. Figure 9 illustrates a plurality of physical lighting devices that appear as virtual lighting devices in a remote controller's graphical user interface 64, specifically the remote controller's GUI 85. The virtual lighting devices 39 correspond to their respective real lighting devices 38 within the structure. In addition to the physical lighting devices 38, there are the physical keypads 40, shown in Figure 6, separated within a structure. The lighting devices 38 can have any form factor, including A20, PAR38, linear cove, wallwasher lights, and track lights. The keypads 40 can be mounted in a single-output junction box and can be connected to the AC mains. Furthermore, the virtual keypads appearing in the wired or wireless remote controller 64 can eliminate the need for the physical keypads 40.Virtual keyboards can exist in GUI applications on computers, and specifically on mobile devices such as smartphones. Keyboards, whether physical or virtual, are typically described as a remote controller if the remote controller consists of a wired physical keyboard or a wireless mobile device that has a GUI in which the virtual keyboard is displayed. In addition to the network of physical lighting devices and physical keyboards, a remote controller is used to control communication to and from the network of physical lighting devices and keyboards. The remote controller is essentially an execution unit that executes instructions and data to present a GUI that the user can use to perform the grouping and scene / exposure assignments described in Figures 10B and 10C.Control instructions are sent via a communication interface from controller 64 to the network of lighting devices 38. The communication interface for controller 64 simply communicates correctly with the lighting devices and keypads using, for example, the ZigBee communication protocol. Remote controller 64 can also communicate via a different protocol if a bridge or node is required to bridge the connection between the ZigBee protocol used by the lighting devices 38 and the protocol used by remote controller 64. For example, a software application could operate on controller 64, possibly on any Apple or Android mobile device, to display a virtual keypad on controller 22. A node or bridge connects a network of Wi-Fi and wireless lamps that can use ZigBee.If the remote controller 64 communicates directly without a bridge or intermediate node, then an electronic key (dongle) with a radio interface will allow the GUI of the remote controller 64 to communicate directly with the network of the physical lighting devices 38 and physical keypads 40. A typical installation in a building will have 40 physical keypads and a variety of 38 physical lighting devices in each room. In some cases, some rooms may have multiple keypads controlling the same lighting devices, such as conventional two-way or three-way light switches, where a three-way switch uses two toggles and a two-way switch uses one toggle for on / off. The 40 physical keypads in each room then control the color, brightness, spectrum, or visual effects in general. The keypads can control these effects either statically or as a timed function. Static control would simply involve a user pressing a trigger button or slider on the physical keypad.Lighting devices and physical keyboards in a residence can also be controlled by a computer running an application with a radio-based electronic key plugged into a USB port, or they can be controlled by a mobile device, such as a smartphone, also running a software application. The electronic key can communicate ZigBee messages directly, while the bridge or node converts between Wi-Fi and ZigBee messages, for example. After the physical lighting devices 38 and physical keypads 40 are installed in a structure, they must be exposed before grouping and scene building procedures. Therefore, a first step when using, for example, a controller with an electronic key, is to expose all lighting devices and keypads within that controller's range. The wireless network used by the lighting devices 38 and keypads 40 is preferably a mesh network, so that lighting devices or keypads that are physically distant can remain within the controller's communication range through one or more hops.When a user commands the controller to expose all devices, possibly via a command in the controller's GUI, the electronic key transmits a message instructing all devices that receive the message, either directly or through any number of hops, to respond with their unique ID number, often referred to as the MAC address. The unique MAC addresses of each lighting device, as well as the keypads, are sent back to the remote controller. If the remote controller is a personal computer or a phone with a screen, it displays a set of GUI icons on that screen as virtual lighting devices, representing the corresponding physical lighting devices that have responded.The icons are referred to as virtual lighting devices because there is a need to distinguish between lighting devices that appear in the GUI as virtual lighting devices 39 and lighting devices that exist in the residence, or physical lighting devices 38. For example, as shown in Figure 9, in an installation with six physical PAR 38 lighting fixtures on a structure, six virtual lighting fixture icons will appear. Keyboards will appear in a later step as virtual keyboard icons as well. An indication that all lighting fixtures have been uncovered occurs when an acknowledgment message is sent back from each fixture to the remote controller, causing each physical lamp to turn blue and each physical keyboard to blink. Additionally, each of the uncovered physical lighting fixtures and physical keyboards will appear as virtual lighting fixture and virtual keyboard icons in the GUI.If all physical lighting devices do not turn blue or the keypads flash during a walkthrough inspection of the residence, not all recognition messages have been returned. Therefore, the failed recognition message for the unique lamp MAC address would indicate that a non-blue physical lamp has not been discovered. In that case, remediation measures, as described below, would be necessary. However, if all physical lighting devices turn blue during the physical inspection, then the corresponding icons will appear, and all physical lighting devices within the residence will be displayed as icons in the controller GUI. After all physical lighting devices and physical keyboards have been discovered, the next step is grouping. In the grouping procedure, physical lighting devices that do not need to be controlled together are assigned a specific group address. As shown in Figure 9, during the grouping process, the group addresses are downloaded to storage medium 56 of each lighting device.Subsequently, during a control mechanism, a single button press on a physical keypad 40 or a press of a group name assigned to a virtual button on a virtual keypad will cause a control message to be sent from the controller to address, via a single group broadcast message, all unique MAC addresses associated with the unique group address to launch the content associated with that group from the physical lighting devices through the microprocessor's pull mechanism. Further descriptions of group addressing and content storage within lighting devices 38 occur during the grouping mechanism, as well as the scene builder or exposure builder mechanism. There can be different types of remote controllers 64 and, in particular, different communication protocols applied to the various lighting devices 38. A remote controller 64 might simply consist of an electronic key with a USB interface and radio plugged into the USB port of a mobile device. If the remote controller 64 is to communicate through a node or bridge, then the remote controller 64 communicates using a different protocol than the one used by the various communication devices 38 to communicate with each other, as well as the physical keypad 40. During the discovery phase, for example, the transmit discovery signal is sent from the remote controller 64 across the hop-to-hop mesh network, with a return acknowledgment, for example, from one address to one address to one address, for example, in hexadecimal. The transmit discovery and return acknowledgment form a routing table with a destination address and the next-hop address for a particular lamp. The routing table is stored in the lighting device's memory 38 along with what will be described later as the group address, as well as the content associated with that group address. The group address and content can have a group address, for example, of F and C, respectively, forming the group transmit table.An example of a lighting device discovery, group transmission table formulation and content (scene / exposure builder) for various lighting device groups and the flowchart for each procedure are set forth in the commonly assigned United States Patent Application with Serial Number 15 / 041,166, which is commonly assigned and incorporated herein by reference in its entirety. The discovery process can be initiated by sending a discovery message. At least once after the 38 lighting devices have been installed, network configuration may be required. This network configuration can be repeated if necessary. Typically, the discovery configuration or procedure is performed only once. However, if a lighting device is replaced, the discovery process must be repeated whenever the lighting system is modified. Therefore, the discovery process may be performed if the network is modified or reconfigured, if lighting devices are added or removed, or if lighting scenes are modified. When the network is configured during the discovery phase, the remote controller is initially unaware of the available lighting devices.The network structure of a lighting system is not predetermined by the installation like the wiring structure of a wired network. Instead, it can be determined by a variety of physical conditions, such as the distance or covering materials between neighboring lighting fixtures, walls, or other devices between lighting fixtures, or even by electromagnetic interference from electrical appliances or other devices within the structure.36 To calculate the network configuration, a transmission is preferably triggered by controller 64. The transmission message is sent to a predefined transmission address, which serves all physical devices (lighting fixtures and keyboard). For example, the transmission signal will first be received by those devices closest to the controller. These lighting fixtures can then forward the transmission message to other lighting fixtures, which in turn forward the message to even more distant lighting fixtures via one or more hops. To complete the network configuration, the controller must receive an acknowledgment signal from each lamp, confirming that it has received a transmission message.The acknowledgment signal is preferably transmitted as a unicast message or a message sent back to the controller that sent the transmission. Each lighting device that sends such a unicast message must receive an acknowledgment to prevent it from retransmitting the same message. Therefore, the return acknowledgment is sent by the controller back through the mesh network, also as a unicast message. During the discovery phase, or discovery process, transmission is time-consuming, as are reception and return acknowledgment, and subsequently sending an acknowledgment response. However, because the discovery process occurs infrequently, and usually only during the initial setup of lighting devices during installation, a time-consuming discovery process that may take several seconds is generally acceptable to the user. Nevertheless, when the discovered lighting devices are subsequently controlled, any delay or time lag, and especially any popcorn effect, will be avoided.Even a fraction of a second, in some cases, is noticeably annoying to a user when running control using the aggregated acknowledgment and group transmission mechanism described below. The discovery procedure, although comparatively slow in relation to the control procedure, begins with a broadcast discovery message through which that message is routed through possibly multiple hops to all the various nodes, including physical lighting devices 38 and physical keyboards 40. Each of those nodes, keyboards, and lighting devices transmits and acknowledges back to the remote controller 64, which must be routed as an acknowledgment signal through the mesh network, where the remote controller 64 then receives the acknowledgment by hopefully having all the unique MAC addresses of the physical lighting devices indicating a blue light output from all those lighting devices and a flashing physical keyboard from the discovered keyboards. Figure 9 illustrates the grouping procedure, where a GUI on the remote controller 64 is used to group not only virtual lighting device icons 39, but also physical lighting devices 38 based on any group specified by a user, or pre-existing groups with pre-existing scenes assigned to them. Figure 9 illustrates a GUI displayed on a remote controller 64 if the remote controller 64 has a screen similar to that of a laptop or phone. Above the GUI, in the left portion, there is an icon representing either groups or keyboards. When the groups icon is selected, as indicated, a series of groups A, B, C, etc., may appear. Depending on the mode, a series of group icons 90 appear. Depending on the mode, the group icons are not mentioned until a user provides a name for them.Thus, for example, Group A might be a name assigned to a group icon, or it could simply be a default name assigned to a group icon. Groups displayed as icons in the Remote Controller 64 GUI can have predefined names, such as Bedroom Projector or Bedroom Nightstand. In this latter case, those predefined names can also have predefined scenes or exposures. For example, Bedroom Projector might have a predefined scene or exposure that is uniquely assigned to projectors or lighting fixtures in the bedroom as stored content in that lighting fixture group. The uniquely assigned scene / exposure is preferably different from the predefined scene or exposure associated with the Bedroom Nightstand lighting fixture group, for example.As shown in Figure 9, after all lighting devices have been discovered and appear as virtual lighting devices 39, or icons, in the right-hand portion of the GUI 85, one or more lighting devices can be grouped by clicking on the virtual lighting device in the GUI, and that virtual lighting device icon 39 may blink or change to a different color. The corresponding physical lighting device or lamp 38 within, for example, a bedroom will also change color, or blink, as shown by the blinking physical lighting devices, which correspond to a blinking icon of the virtual lighting device 39.In this way, the user will then know the correspondence between the icons of the virtual lighting device and the physical lighting devices so that when he or she runs the grouping procedure, it is known which lighting device (virtual and physical icon) is assigned to each group as shown in Figure 9, where the lighting device for bedroom 38 corresponding to the virtual lighting device 39 is assigned to group A. As an example, if there are three rooms with a keyboard in each room (i.e., kitchen, living room, and bedroom), in the bedroom there might be two A20 lighting fixtures on the nightstands and two PAR38 lighting fixtures on the ceiling. The user might want to control these two groups of physical lighting fixtures independently, so two groups are created and named bedroom projectors and bedroom nightstands, and these groups are displayed as a separate group name in the GUI 85's Group 90. In the living room, there might be three A20 lighting fixtures and four PAR38 lighting fixtures. The user might want to create three group icons named Group 90 comprising one A20 on a corner table next to a chair, two A20s on either side of the armchair, and four PAR38s on the ceiling, so three groups are created named living-projector, living-corner-table-chair, and living-corner-table-armchair.The named group icons can be user-named or predefined with associated scenes and exposures. In the kitchen, there might be four PAR38s on the ceiling that are controlled together, creating a group called "kitchen-projector," or it might pre-exist with an associated scene / exposure. Using the previous example, there are six groups of virtual lighting device icons on the left side, with ten PAR38 lamp icons (virtual lighting devices) and five A20 lamp icons (virtual lighting devices) on the right side of the GUI. All the lights remain blue. When the user clicks a lamp icon, the corresponding physical lamp and its associated MAC address momentarily change color, as shown, for example, when the virtual lighting device icon is clicked. The user then, for example, drags and drops the two virtual lamp icons into the group on the left, labeled Group A, or bedroom-nightstands, for example.This process can be continued for the other groups where, for example, the user can click on the PAR38 virtual lamp icons until the two in the bedroom are identified, and then drag and drop those virtual lamp icons into a group called Group B or Bedroom-Projectors, for example. When a virtual lamp icon is dragged into a group, the associated physical lamp reverts to its default light color, for example. The user can perform the same grouping procedure in the living room, kitchen, or throughout the building. At this point, all the virtual lighting device icons on the right side of the GUI have been identified because, for example, they have been dragged and dropped into a corresponding group named Group Icon 90. Furthermore, all the physical lighting devices are producing white light. The next step is to configure the physical keypads in each room.The configuration of virtual keyboards using, for example, a mobile phone control device will be described below. However, the configuration of physical keyboards is described here. When configuring keyboards, the user can click on a different tab, for example, tab B, instead of tab A at the top of the GUI. By clicking on another tab associated with the keyboards, the buttons on each keyboard can be configured to produce a particular brightness, color, spectrum, and visual attribute setting for a particular group of lighting devices. The device control procedure for configuring specific buttons on a physical keyboard is shown in more detail with reference to Figures 10A, 10B, and 10C. For example, configuring a particular keyboard begins by selecting the keyboard, as shown in Figure 10A, by selecting the virtual keyboard icon 92 after clicking the keyboard icon in the left portion of GUI 85. Once the virtual keyboard icon 92 is identified, it can be assigned to one or more named group icons 90 or a predefined named group icon. Subsequently, as shown in Figure 10B, GUI 85 changes its display to show a virtual keyboard 92 with corresponding virtual trigger buttons 98. The virtual buttons 98 can be replaced with a virtual slider, all within the category of a trigger. Five virtual buttons are shown; however, there could be more or fewer buttons as required.A scene or exposure can be associated with a selected virtual scene / exposure cone 100 by dragging and dropping it onto the corresponding shutter release button 98. In this way, each button on the virtual keyboard 92 can operate as a shutter release slider. The longer the button is pressed, the higher the slider position. Each shutter release button can have an associated control over one or more groups of physical lighting fixtures 38 within a setup, and a corresponding scene or exposure can be assigned to each of those groups of lighting fixtures 38 by downloading the corresponding content to the physical lighting fixtures 38. Assigning a group or a scene / exposure can also be done from a drop-down menu, instead of using the drag-and-drop method. As an example, if there are two buttons that control the bedroom-projector group and the bedroom-nightstand group, the two top buttons could control each of those groups. The user assigns a particular color temperature, brightness, or any other visual attribute to each of the various buttons—in this case, the virtual buttons on the virtual keyboard. The bottom button, for example, can be assigned to all the groups controlled by the corresponding physical keyboard, and the bottom button can be assigned to turn off all the lights associated with the various groups attributable to that keyboard. The process of describing button grouping for a bedroom can be repeated for the living room, the kitchen, and all the remaining physical keyboards within the structure. The grouping occurs through the configuration of the virtual keyboard, which then corresponds to the appropriate physical keyboards.The trigger buttons are selected and assigned to predefined or non-predefined groups of lighting devices, as well as scenes and exposures that control those groups. After being programmed into the various virtual buttons of the virtual keyboard displayed in the controller's GUI 64, the corresponding group addresses and the corresponding content of the assigned scenes and exposures are downloaded from the virtual keyboard 92 to the corresponding physical keyboard 40 in Figure 1. The physical keyboard 40 will operate identically to the virtual keyboard 92, since pressing any button corresponding to the five buttons on the virtual keyboard will send a group transmission control message to the physical lighting devices iL / nLn / zznz / E / YiAi that are controlled by the physical keyboard.Furthermore, similar to the identification of physical lighting devices when virtual lamp cone grouping is running, the physical keyboard 40 associated with virtual keyboard 92 will blink when that virtual keyboard is selected. For example, when virtual keyboard 92 is selected within the driver 64 GUI, the corresponding physical keyboard 40a, 40b, etc., will blink, indicating to the user which keyboard within the structure has been selected. As shown in Figure 10B, along with the five virtual buttons 98 on the virtual keyboard 92 are the up / down buttons 104. The up / down trigger buttons can be programmed on the virtual keyboard 92 and can have a corresponding programmed effect on the physical keyboard 40. For example, once a corresponding button on the physical keyboard 40 is pressed after being programmed using the virtual button in the GUI, the corresponding group of physical lighting devices illuminates. The physical keyboard 40 or the virtual keyboard 92 can have buttons or touch lights corresponding to the up / down buttons on the virtual trigger slider 104, which operate on the virtual keyboard as well as on the physical keyboard to adjust the brightness of the lights controlled by the last button pressed on the physical / virtual keyboard, for example.Thus, if the top button on the physical or virtual keyboard associated with the bedroom sets the projector to red at half brightness, the up / down arrows would adjust the projector's brightness after the top button on the physical / virtual keyboard is pressed. The up / down arrows would control the brightness of the bedroom nightstands after, for example, another button associated with the bedroom nightstand group is pressed. When an up / down arrow is pressed, a message is sent using group broadcast addressing to the group of physical lighting devices associated with the keyboard button. Alternatively, the up / down trigger 104 can control all groups of lighting devices controllable by that keyboard.For example, all groups associated with the virtual or physical keypad are dimmed or their dimming is reversed, not just those controlled by the last pressed button 98. Also, as noted earlier, the trigger can include the 98 buttons or the up / down 104 buttons. The duration for which a button 98 is pressed acts as a trigger slider, or the appropriate up / down 104 button among the group of five, for example, can also act as a trigger slider for the last pressed button 98 or all the buttons 98 assigned to all lighting devices within one or more rooms controlled by those buttons 98. According to one method, the group assigned to a virtual button or virtual keyboard, and therefore to the physical button on the physical keyboard, can also be assigned to a predefined scene or exposure through the use of a dropdown icon. The dropdown observes the predefined scene or exposure applied to a group, and through the controller's GUI, the group and its corresponding scene or exposure are applied, for example, to a virtual button on the virtual keyboard, which then downloads that group, scene, or exposure to a physical button on the corresponding physical keyboard that was flashing to indicate that it was selected for programming.After all buttons have been programmed to their corresponding predefined group name with the predefined scene and exposure, or according to another modality, to any user-defined or non-predefined group name or scene and exposure, the physical keyboard may stop blinking during the discovery / configuration process. Once the virtual keyboard icon is dragged and dropped to the left side of the GUI screen, the user can then enter a name for that keyboard, such as bedroom_1, for example. To program the buttons on the virtual / physical keyboard, the user selects the virtual keyboard on the left side of the GUI screen, which is preferably previously named with something identifiable to the user. According to one modality, if the scene and exposure were not predefined and assigned to a predefined group name, but are instead defined by a user to allow a button to assume any possible, substantially unlimited number of scenes or exposures, a user can select the Create Scene or Exposure button 106 as shown in Figure 10B. A corresponding GUI will then appear on the remote controller 64 as shown in Figure 10C. The GUI allows the user to manually control any color temperature, brightness, or visual attribute to be assigned by clicking the manual control 108. The manual control can then bring up a blackbody curve 110 to allow a user to choose any color temperature along that blackbody curve 110, or manually select a visual attribute, color temperature (CCT), and / or brightness, etc., using the sliders 112 for each.In addition, the user can assign times, either in increments or by the hour, to each attribute—color temperature or brightness—to automatically change the color temperature of an exposure. The time can be programmed, for example, for the day to automatically and dynamically change the color temperature throughout the day, from sunrise to sunset. The exposure can also be extended past sunset into night. The change in the color temperature output of the designated group or groups of lighting devices means that the created exposure is automatic, depending on the exposures stored in the corresponding group or groups of lighting devices.The change in color temperature can also be effected as a series of scenes triggered by multiple time-of-day signals sent from a timer within the remote controller (either a virtual keyboard 92 or a physical keyboard 40). Therefore, the remote controller 64 includes a real-time clock that generates multiple time-of-day signals based on the calendar day and time of day during daylight hours. These time-of-day signals can be synchronized via a crystal oscillator connection, an internet connection, or a satellite connection. Depending on which of the multiple time-of-day signals is sent, the color temperature output of the corresponding group of lighting devices responds by sending a group transmission signal to the grouped set of lighting device MAC addresses.A different time-of-day signal is sent at different times during daylight hours to trigger a different color temperature output from the targeted group of lighting fixtures. A user can then program the bedroom group of lighting fixtures to operate at a different emulated sunlight than, for example, the kitchen group of lighting fixtures. Even when the same time-of-day signal is sent to both the bedroom and kitchen groups (for example, mid-morning), the stored exposure in the bedroom lighting fixtures may produce a lower color temperature, such as 2300 Kelvin, or may turn off, while the kitchen lighting fixtures may produce a higher color temperature, close to 6000 Kelvin. Alternatively, the user can program the time-of-day signals at different times for the kitchen versus the bedroom.For example, the time-of-day signal at sunrise might appear earlier in the bedroom than in the kitchen. Having a separate remote control for the kitchen versus the bedroom, and programming the timers differently in each, allows for selective adjustment of the exposure and, subsequently, selective manual cancellation of each. Returning to Figure 11, a graph of the spectral sensitivity of luminosity to different wavelengths of color is shown. Even though lighting devices of various wavelengths are physically equal in energy, the visual system is not equally sensitive to different wavelengths. For example, luminance, or brightness, can be expressed even though lights of equal energy produce the same effect at all spectral wavelengths; in fact, not all wavelengths appear to shine equally. Photopic luminance is defined as L = cJP(A)V(A)dA, where P is the spectral energy and V is the photopic spectral sensitivity of the standard observer. As shown in Figure 11, luminance can be expressed by the fact that lighting devices of equal energy but different wavelengths do not appear to shine equally to the standard observer.Further details regarding the relationship between color temperature as a function of brightness and time of day will be described below with reference to Figure 15. However, according to one approach, it is sufficient to know that lower color temperatures are more affected by changes in brightness and time of day than higher color temperatures. According to another approach, varying brightness throughout the day, even with the same change in brightness, can produce the same change in color temperature throughout the day. Figure 12 illustrates what happens when a remote controller 64, such as a virtual / physical keyboard, receives user input, for example, on a trigger slider, to produce different intensity values ​​sent to the interface 52. The intensity values ​​correspond to trigger position values.The relationship between the trigger position / status and lumen output is shown in Figure 12. The 54 driver converts the trigger position / status into lumen output and color temperatures using tables and interpolation. These conversion functions differ at different times of day. Once the desired lumen output and color temperatures are known, the 54 driver calculates the required drive currents for each LED string. This value, applied to all LED strings, represents the current or energy needed to change the brightness output of all the LED strings. As observed in Figure 12, changes in the slider movement to produce changes in intensity on the virtual / physical keyboard, or on a triac dimmer associated with the physical keyboard, result in a nonlinear change in brightness. In other words, there is a nonlinear relationship between the intensity output of the slider movement and the brightness output. Storage medium 56 then contains a first nonlinear mapping of the intensity value to the brightness value, such that each incremental change in the slider position on the virtual / physical keyboard or dimmer will correspond to a brightness value mapped according to a series of points along the nonlinear curve shown in Figure 12. The map or graph of intensity versus the nonlinear brightness curve is generally known as the brightness dimension curve, and it is mapped as a first mapping within the storage medium.The movements of the trigger slider through the user cause a resulting brightness output, and the gradual movement and recording of the brightness output is then used to formulate the first mapping which is then stored in the i L / nLn / zznz / E / YiAi storage medium 56 for later use. Figures 13A and 13B illustrate what happens when a user triggers the timer at different times of day. These times of day are those sent from a timer, for example, within a physical / virtual remote control keypad. The first time of day might be before sunrise, followed by a second time of day that triggers a sunrise event. The times of day before sunrise, at sunrise, in the morning, and at midday each direct a different set of data or content stored within the corresponding group or groups of lighting devices. For example, a timer triggering a pre-sunrise time of day triggers the first set of data for automatic exposure and sends the appropriate current ratio to the LED strings to produce a relatively low color temperature.Therefore, the timer triggers an initial display, which includes a relatively low lumen output and color temperature. Prior to the automatic switch that occurs during exposure to a higher color temperature—for example, during a morning time of day that would normally produce 3200 Kelvin—a manual adjustment on a trigger, such as a dimmer or physical keypad, will reduce the brightness by 120. Importantly, for that 120-point reduction in brightness, the color temperature, which would normally rise to 3200 Kelvin, will be significantly lower. This 120-point reduction in brightness and the significant reduction in color temperature can remain in effect for a limited time, until the next time-of-day signal is sent, or until the following time-of-day signal is sent, or until the trigger is pressed again to release manual override mode. The significant reduction in color temperature during manual cancellation dimming when a trigger is activated (or the increase in color temperature during a dimming reversal) can occur without any fading. However, it is desirable to fade the automatic color temperature changes that occur during exposure and prior to manual cancellation. Furthermore, it is desirable to have fewer time-of-day signals sent from the timer to minimize the amount of automatic fading of color temperature changes. As shown in Figure 13B, for example, one hour after sunrise, an initial time-of-day signal is sent to increase the color temperature in a plurality of steps 121, linearly 123, or exponentially 125 over a fixed time that is preferably less than two hours and more preferably less than one hour.To minimize the number of time-of-day signals, there could be one additional time-of-day signal that decreases the color temperature in multiple steps, either linearly or exponentially, over one or two hours, one hour before sunset. Having only two time-of-day signals and sending those signals twice a day would significantly reduce the amount of communication required to run the exposure, and would also reduce the amount of content that needs to be stored on one or more lighting fixtures. Figure 13B also illustrates the same reduction in brightness 120 as that shown in Figure 13A if, for example, a user moves the slider on the physical keypad or dimmer by the same amount as they did one hour after sunrise (i.e., in the morning) in Figure 13A. However, in Figure 13B, the same reduction in brightness 120 produces significantly less reduction in color temperature if the slider is moved at midday than at sunrise as shown in Figure 13A. At midday, the color temperature, which is automatically and dynamically set to be, for example, 6500 Kelvin, is reduced slightly to less than 6500 Kelvin (<6.5 Kelvin), and that reduction is much smaller than the reduction that would occur in color temperatures during the morning hours or sunrise ("<3.2K Kelvin").Therefore, the effect of changes in brightness on color temperature depends on the time of day because, as shown earlier, spectral sensitivity is deeper in LED strings producing a lower color temperature than in LED strings producing a higher color temperature. Even when the power or current supplied to all LED strings changes by the same amount based on changes in intensity, the color temperatures—for example, cool white, which has a predominantly blue spectral output at midday—will change less than the predominantly red spectral output produced during sunrise or early sunrise. A circadian exposure can be used to emulate sunlight at various times of day and can be continued across different groups of lighting devices within a structure. However, if a specific task is required for a particular group of lighting devices, or if the emulation needs to be changed to more closely resemble outdoor daylight conditions, the circadian exposure can be manually modified by a user to have a greater effect on color temperature at certain times of day than at other times. A significant benefit of the present invention is the greater effect of changes in brightness on color temperature one hour after sunrise and one hour before sunset than at any time in between, for example. It is desirable, even when dimming occurs manually, to have a lesser effect on color emulation at higher color temperatures than at lower color temperatures, so that the circadian rhythm is not significantly disrupted even when a user manually changes the circadian exposure that occurs automatically during daylight hours. In other words, it is more convenient to change the circadian exposure to a warmer color temperature during warm white lighting periods than during cool white lighting periods, which typically occur during peak sunlight hours. In this way, the manual adjustment required to perform a task or to more closely resemble actual outdoor daylight conditions remains more consistent with those conditions.Warm white stays warm white longer, while cool white stays cool white, etc. Dimming can also be reversed manually. During nighttime hours, a user can trigger a switch to manually cancel an automatically changing color temperature display that can be programmed to have no light output regardless of the sent time-of-day signal, or in this case, the sent nighttime time-of-day signal. For example, a user might want to press a trigger button or an up / down button on the bedroom's physical keypad to cancel the no-light output display in order to increase the brightness and color temperature within the group of lighting fixtures in the bedroom.The convenient reversal of the dimming causes a lower color temperature to be emitted to emulate the incandescent light output that would normally occur when a user wakes up in bed and turns on an incandescent light during the night. Manually canceling the dimming reversal that occurs at night is similar to daytime, in that a change in brightness will have a greater effect at lower color temperatures than at higher color temperatures. The present invention thus applies to a circadian exposure that extends beyond daytime, and the manual cancellation also applies to any change in brightness and its effect on lower color temperatures more than on higher color temperatures. Returning now to Figure 14, storage medium 56 can contain content or data sets associated with the lighting device that contains storage medium 56. A group of lighting devices, possibly grouped according to the description shown in Figures 9 and 10A to 10C, can contain the same content for the corresponding group of lighting devices. For example, the content in the color temperature settings for various times of day 124, or various conditions that a sensor can detect 126. The various times of day 124 or sunlight conditions 126 stored in each of a group of lighting devices that have storage medium 56 are triggered by a time message in the case of time of day 124 or sensor readings in the case of sunlight conditions 126. As shown in Figure 14, a time message can activate, or act upon, content stored on storage medium 56 depending on the value of that time message. For example, if it is to run on the midday data set 124, then the time message would most likely be at or near the local midday time for that timer within the remote controller. The timer or real-time clock with a remote controller 64 can send the appropriate time message to address the appropriate time-of-day content 124. The time message would change the color output of the corresponding group of lighting devices that have similarly stored time data sets or content. Alternatively, a button that would call a specific exposure, such as button 1 calling exposure A, would cause exposure A to start when button 1 is pressed.This would cause the appropriate time message to be sent or, alternatively, timers could be found within each of the lighting devices that automatically change the extracted content at regular periodic intervals simply by starting exposure A, for example. If the time message is sent from the remote controller timer or the timer exists within the group of lighting devices based on the programmed exposure, a periodically changing sequence, which automatically changes content or data sets, is executed by the control circuit controller 54 to emulate the changes in sunlight along the daytime locus, from as low as 200 Kelvin during sunrise to a maximum of over 6000 Kelvin at midday and then falling again to less than 2000 Kelvin at sunset, for example.According to an alternative modality, a sensor similar to the temperature sensor 58 can be used to measure sunlight, either inside or outside the structure, and then based on the sensor readings, the extracted and executed content or data set can be automatically and dynamically changed so that the detected daylight can be emulated not only along the daytime locus but at any point or chromaticity spectrum. Figure 15 is a graph of color and, specifically, color temperature (CCT), changing as a function of both time of day and ambient light. The color temperature, for reasons described earlier, changes automatically and dynamically throughout the day. As shown, the color temperature output of the plurality of LED strings changes automatically to replicate the actual sunlight conditions outside the structure and, for example, emulate the natural sunlight needed for treatments of circadian rhythm disorders. During off-peak sunlight hours, such as before sunrise, in the early morning hours before sunrise, and during the late afternoon and evening hours at sunset, the color temperature can emulate sunrise and sunset times along the daytime locus.Ideally, during the morning and afternoon hours, the target color temperatures are lower than, for example, 3200 or 3000 Kelvin, and around midday the target color temperature can be as high as 6000 or 6500 Kelvin. 6000–6500 Kelvin can emulate the blue of the midday sky, while 3500 or less than 3000 Kelvin can emulate a predominantly yellow mixture with some red in the morning or afternoon sky. Figure 15 illustrates different times of day (TOD), starting with TOD1 through TOD6, and possibly more. Figure 15 also shows a change in brightness, for example, from full brightness (BR1) to a brightness lower than full brightness, or BR2. In one mode, the brightness changes from a constant BR1 level throughout the day to a constant BR2 level. In another mode, the brightness changes from a BR1 level that varies throughout the day to a BR2 level that also varies throughout the day. In either mode, the brightness changes from BR1 to BR2, causing an effect on the color temperature that varies depending on the time of day, with relatively little effect on TOD4, but a greater effect on TOD1-3 and TOD5 and TOD6. The difference in color temperature for the same change in brightness is shown by the different arrows 130 and 132. Arrow 130 indicates a greater change in color temperature than arrow 132, although the change in brightness from BR1 to BR2 is the same.The change in brightness is achieved by changing the intensity of the remote controller or dimmer. As the trigger on the remote controller or dimmer is reduced, for example, to half its setting, the intensity can be reduced by half, and, according to the first brightness-to-intensity mapping shown in Figure 12, the brightness can be reduced nonlinearly by an amount close to half of the previous brightness. If BR2 represents half the brightness relative to BR1, the color temperature changes not only as a function of brightness but also as a function of the time of day. At midday, for example, even if the slider has been moved to, for example, half brightness, the color temperature remains relatively unaffected.This effect is valuable because at midday, when a user wants to perform a task and reduce brightness by manually adjusting the slider, it's desirable to set the emulated sunlight to natural sunlight conditions of 6000 Kelvin or higher, even when the slider is moved. This ensures that the emulated daytime sunlight conditions, after manual adjustment, still appear normal to what is happening outside. In other words, the natural daytime sunlight conditions emulated by the multiple LEDs remain close to peak sunlight even when a user adjusts the brightness along the dimming curve.Conversely, if a user adjusts the dimming along the dimension curve during sunrise or early morning hours, the color temperature will drop more than at midday because the actual sunlight conditions during those hours are more in the warm white color temperature range, and any changes to the dimming will further retain the warm white conditions occurring outdoors. Figure 15 also shows, in a dashed line according to a second mode, the changes in brightness from a BR1 level that varies during the day to another BR2' level that also varies during the day. In this mode, any movement of the trigger slider to manually cancel will have the same effect on the color temperature change during the day, as shown by arrow 130 and arrow 132' indicating equal amounts of change at different times of day. A key advantage of this preferred mode is that when tasks are performed, for example, and brightness is reduced via a user-adjusted dimming curve, the emulated natural sunlight condition is maintained. Continuing to emulate sunlight conditions during the early morning hours and beyond, even when manual dimming and reversal occur, is beneficial for psychological and aesthetic reasons. For instance, shortly after sunrise and shortly before sunset, it may be more desirable for the lighting to emulate incandescent lighting, such as halogen, which produces a warmer white color temperature.Color emulation is therefore best suited for implementation as an astronomical display because natural lighting changes more dramatically based on whether the sun is high or low, and specifically the length of its path. However, when performing certain tasks, it is necessary not to tie the brightness to a time-based exposure, and therefore a preferred mode allows the user to adjust the brightness as needed. By changing the brightness at midday, for example, changes in the brightness of the emulated sun at its peak sunlight condition, retaining that high color temperature or peak sunlight condition. Conversely, changing the brightness during the morning or afternoon hours changes the brightness of the emulated incandescent lighting, where it is more desirable to produce an even greater decrease in color temperature than at midday.Therefore, the preferred modes of the same are not necessarily designed for automatic and dynamic changes in color temperature during the day, but rather are designed for task lighting conditions required by a user periodically during the day, where the brightness can be modified, although the effect on color temperature depends on the time of day at which the dimmer is activated by the user. Figure 16 illustrates the effect on color temperature, or CCT, when the brightness is manually adjusted at different times during the morning and midday (TOD3 and TOD4). Specifically, Figure 16 shows a greater change in color temperature when the brightness is manually changed from BR1 (shown as a solid line) to BR2 (shown as a dashed line) during the morning hour of TOD3 versus the midday hour of TOD4. In TOD3, when the brightness changes from BR1 to BR2, as shown by arrow 134, the color temperature drops substantially. However, as shown by arrow 136, when the brightness changes from BR1 to BR2, the color temperature does not drop nearly as much during the midday hour of TOD4 as it does during the morning hour of TOD3. Of course, Figure 16 is an example of various TODs and is not representative of the use of only two TODs.One hour after sunrise and one hour before sunset, and possibly sunset or nightfall. Furthermore, Figure 16 does not illustrate the TODs after sunset, or the dimming reversal that can occur either during the day or after nightfall. Also, Figure 16 does not illustrate the automatic fading changes to color temperatures that would occur at each TOD. Figure 17 illustrates how user input from manually triggered devices, such as a slider, on a triac dimmer or associated with a virtual physical keypad, produces intensity values ​​fed to a brightness dimension curve module 140. This module contains a first nonlinear mapping of the intensity value to the brightness value within the storage medium and maps a brightness value corresponding to the input intensity value to the dimension curve module 140. A color emulation module 142 receives the brightness value, as well as time-of-day messages, or TOD values, from, for example, a timer 144. The combination of TOD values ​​and brightness (BR) values ​​is received by a second color temperature mapping as a function of the time of day, as well as the brightness input.The color emulation module 142 then performs the second color temperature mapping as a function of the time of day, as well as the input of the light level. The color emulation module 142 produces the corresponding color temperature along the X / Y chromaticity graph and specifically along the blackbody color temperature curve. Knowing the appropriate chromaticity, the chromaticity module 146 can comprise the control circuitry and the LED driver circuits to control each of the LED strings by sending the appropriate drive current to each of the plurality of LED strings. The chromaticity module 146 then comprises the control and drive of the plurality of LED strings to produce the appropriate illumination for each of the plurality of LED strings.The combination of the first and second mappings through the luminosity dimension curve module 140 and the color emulation module 142 produces the appropriate drive currents within the chromaticity module to maintain the emulation of sunlight that depends on the time of day, as well as changes in luminosity. Those skilled in the art who benefit from this disclosure will appreciate that this invention is considered to provide an improved lighting device, system, and method that not only emulates sunlight during the day, but, as lighting tasks require, this emulation can be maintained by conveniently adjusting the color temperature during the morning and evening hours rather than at midday, for example. Further modifications in alternative embodiments of the various aspects of the invention will become apparent to those skilled in the art by virtue of this description. Therefore, the following claims are intended to be interpreted to encompass all such modifications and changes, and the specification and drawings are to be regarded accordingly in an illustrative rather than restrictive sense.

Claims

1A lighting device, comprising: a plurality of light-emitting diode (LED) strings, each of the plurality of LED strings being configured to produce illumination for the lighting device at a chromaticity consistent with a chromaticity setting; an actuator circuit coupled to the plurality of LED strings that automatically changes a color temperature output of the lighting device as a function of a time of day; a control module coupled to the actuator circuit for sending a brightness value to the actuator circuit, said control module comprising: a coupled interface for receiving an intensity value; a storage means comprising a first nonlinear mapping of the intensity value to the brightness value, and a second mapping of the color temperature as a function of the time of day;and a coupled controller to receive a change in intensity value from the interface and extract the first and second nonlinear mappings from the storage medium to produce a greater change in color temperature closer to sunrise or sunset than during midday, although the change in brightness resulting from the intensity value is the same at sunrise, sunset, and midday. 2, - The lighting device according to claim 1, wherein each of said plurality of LED strings is configured to produce a spectral wavelength range.

3. The lighting device according to claim 1, wherein the actuator circuit automatically changes the color temperature by applying different actuator currents to each of the plurality of LED strings as a function of the time of day. 4 - The lighting device according to claim 3, wherein the different drive currents for each of the plurality of LED strings automatically change as a function of the time of day to change the color temperature output to emulate changes in natural sunlight.

5. The lighting device according to claim 3, wherein the different drive currents for each of the plurality of LED strings change automatically depending on the position of the sun. 6 - The lighting device according to claim 1, wherein the interface comprises a wired or wireless interface for receiving the change in intensity value when a user activates a button or slider on a remote controller coupled by wire or wireless means to the interface.

7. The lighting device according to claim 1, further comprising a dimmer coupled to the controller to forward the change in intensity value from the dimmer when a user operates a button or slider on the dimmer.

8. A lighting system comprising: a plurality of light-emitting diodes (LEDs) configured to produce a plurality of color temperatures along a blackbody curve; and a timer for producing a plurality of daylight hours, comprising a first daylight hour at sunrise or sunset and a second daylight hour at noon;a drive circuit coupled between the timer and the plurality of LEDs to receive the plurality of hours of the day and send a drive current to the plurality of LEDs to produce a first color temperature during the first hour of the day and a second color temperature during the second hour of the day, wherein the timer is remote from the drive circuit and wirelessly or via a wired connection forwards a plurality of hours of the day to the drive circuit as well as to a control module, each of the plurality of hours of the day having a different hour value from the others of the plurality of hours of the day; a remote controller coupled to produce an intensity value;The control module coupled between the remote controller and the actuator circuit to receive the intensity value and send a brightness value has a non-linear correspondence with the intensity value for each of the plurality of LEDs. Said control module comprises: a storage medium comprising a first non-linear mapping of the intensity value to the brightness value, and a second mapping of the color temperature as a function of the time of day; and a coupled controller to receive a change in the intensity value from the remote controller, extract the first and second non-linear mappings from the storage medium, and produce a greater change in color temperature during the first hour of the day than during the second hour of the day, although the change in brightness resulting from the intensity value is equal at sunrise, sunset, and noon.

9. The lighting system according to claim 8, wherein the timer comprises a real-time clock that changes depending on the position of the earth in which the remote controller resides, and the plurality of daytime hours produced by the timer comprises a regular time interval.

10. The lighting system according to claim 8, wherein the plurality of hours of the day are values ​​that change depending on the position of the sun relative to where the timer is on the ground.

11. The lighting system according to claim 8, further comprising a dimmer coupled to the AC power network and comprising a trigger which, when activated by a user, changes the intensity value produced from the dimmer and which correspondingly changes the brightness value non-linearly and, depending on the time of day, changes the color temperature by different amounts. 12 - The lighting system according to claim 11, wherein the dimmer trigger, when operated by a user, reduces the intensity value and the brightness value, causing the color temperature to decrease more during one hour after sunrise and one hour before sunset than during the intermediate hours.

13. The lighting system according to claim 8, further comprising a dimmer coupled to the AC power network and comprising a trigger which, when activated by a user, changes the intensity value produced by the dimmer and which correspondingly changes the brightness value equally among the plurality of LEDs and, depending on the time of day, changes the i L / nLn / zznz / E / YiAi a first controller coupled to receive a change in intensity value from a remote controller which is far from the first remote controller and connected wirelessly or by cable to the first controller, and wherein the first controller is coupled to receive a change in intensity value and, in response thereto,producing a change in the color temperature output exclusively only in the first group of LED lighting devices during the first hour of the day relative to the second hour of the day.

20. A lighting device comprising: a plurality of light-emitting diode (LED) strings; an actuator circuit coupled to the plurality of LED strings for automatically fading a color temperature change of the LED strings depending on the time of day, wherein the automatic fading comprises fading the color temperature change in a plurality of steps over a fixed amount of time without user activation of a trigger on the remote controller, and wherein the plurality of steps increases the color temperature one hour after sunrise; a control module coupled to the actuator circuit,Said control module comprises: a controller coupled to receive a change in intensity value from a remote controller located far from the controller and connected wirelessly or via a cable to the controller, wherein the controller is coupled to receive the change in intensity value and, in response thereto, produce a change in the color temperature output from the LED strings during a first hour of the day relative to a second hour of the day. 21A lighting device, comprising: a plurality of light-emitting diode (LED) strings; an actuator circuit coupled to the plurality of LED strings to automatically fade a color temperature change from the LED strings depending on the time of day,wherein the automatic fading comprises fading the color temperature change linearly over a fixed amount of time without user activation of a trigger on the remote controller, and wherein the linear change increases the color temperature one hour after sunrise; a control module coupled to the actuator circuit, said control module comprising: a controller coupled to receive a change in intensity value from a remote controller that is distant from the controller and connected wirelessly or via a cable to the controller, and wherein the controller is coupled to receive the change in intensity value and, in response thereto, produce a change in the color temperature output from the LED strings during a first hour of the day relative to a second hour of the day.

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