# Patent

## Title
Tunable LED lamp for producing biologically-adjusted light

## Abstract

A tunable LED lamp for producing biologically-adjusted light having a housing, a power circuit, a driver circuit disposed within the housing and electrically coupled with the power circuit, and a plurality of LED dies electrically coupled to and driven by the driver circuit. The driver circuit may drive the plurality of LED dies to emit a pre-sleep light having a first spectral power distribution and a general illuminating light having a second spectral power distribution. The pre-sleep light may be configured to affect a second biological effect in an observer. The LED lamp may be configured to fit in a troffer fixture. The LED lamp may also be a troffer fixture.

## Background
RELATED APPLICATIONS
This application is a continuation of and claims benefit under 35 U.S.C. §119 of U.S. patent application Ser. No. 13/968,914 titled Tunable LED Lamp for Producing Biologically-Adjusted Light filed Aug. 16, 2013, which in turn is a continuation-in-part of U.S. patent application Ser. No. 13/311,300 entitled Tunable LED Lamp for Producing Biologically-Adjusted Light filed Dec. 5, 2011, the content of each of which is incorporated in their entireties herein by reference, except to the extent disclosure therein is inconsistent with disclosure herein. Additionally, the content of U.S. patent application Ser. No. 13/968,875 entitled Tunable LED Lamp for Producing Biologically-Adjusted Light filed Aug. 16, 2013 is incorporated in its entirety herein by reference, except to the extent disclosure therein is inconsistent with disclosure herein.


FIELD OF THE INVENTION
The present invention relates to systems and methods of providing a lighting device to emit light configured to have various biological effects on an observer.
BACKGROUND OF THE INVENTION
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.
Melatonin is a hormone secreted at night by the pineal gland. Melatonin regulates sleep patterns and helps to maintain the body's circadian rhythm. The suppression of melatonin contributes to sleep disorders, disturbs the circadian rhythm, and may also contribute to conditions such as hypertension, heart disease, diabetes, and/or cancer. Blue light, and the blue light component of polychromatic light, have been shown to suppress the secretion of melatonin. Moreover, melatonin suppression has been shown to be wavelength dependent, and peak at wavelengths between about 420 nm and about 480 nm. As such, individuals who suffer from sleep disorders, or circadian rhythm disruptions, continue to aggravate their conditions when using polychromatic light sources that have a blue light (420 nm-480 nm) component.
Curve A of FIG. 1 illustrates the action spectrum for melatonin suppression. As shown by Curve A, a predicted maximum suppression is experienced at wavelengths around about 460 nm. In other words, a light source having a spectral component between about 420 nm and about 480 nm is expected to cause melatonin suppression. FIG. 1 also illustrates the light spectra of conventional light sources. Curve B, for example, shows the light spectrum of an incandescent light source. As evidenced by Curve B, incandescent light sources cause low amounts of melatonin suppression because incandescent light sources lack a predominant blue component. Curve C, illustrating the light spectrum of a fluorescent light source, shows a predominant blue component. As such, fluorescent light sources are predicted to cause more melatonin suppression than incandescent light sources. Curve D, illustrating the light spectrum of a white light-emitting diode (LED) light source, shows a greater amount of blue component light than the fluorescent or incandescent light sources. As such, white LED light sources are predicted to cause more melatonin suppression than fluorescent or incandescent light sources.
As the once ubiquitous incandescent light bulb is replaced by fluorescent light sources (e.g., compact-fluorescent light bulbs) and white LED light sources, more individuals may begin to suffer from sleep disorders, circadian rhythm disorders, and other biological system disruptions. One solution may be to simply filter out all of the blue component (420 nm-480 nm) of a light source. However, such a simplistic approach would create a light source with unacceptable color rendering properties, and would negatively affect a user's photopic response.
SUMMARY OF THE INVENTION
With the foregoing in mind, embodiments of the present invention are related to light sources; and more specifically to a light-emitting diode (LED) lamp for producing a biologically-adjusted light.
Provided herein are exemplary embodiments of an LED lamp for producing an adjustable and/or biologically-adjusted light output, as well as methods of manufacturing said lamp. Embodiments of the invention may comprise a tunable light-emitting diode (LED) lamp for producing biologically-adjusted light, comprising a housing comprising a first cap positioned at a first end of the housing and a second cap positioned at a second end of the housing, each of the first and second ends comprising an electrical contact. The LED lamp may further comprise a power circuit disposed within the housing having electrical leads attached to at least one of the first and second caps, a driver circuit disposed within the housing and electrically coupled with the power circuit, and a plurality of LED dies electrically coupled to and driven by the driver circuit. The driver circuit may be adapted to drive the plurality of LED dies to emit a general illuminating light having a first spectral power distribution and a pre-sleep light having a second spectral power distribution. Additionally, the pre-sleep light may be characterized by characterized by a blue output intensity level, in a visible spectral output range of between 380 nm and 485 nm, that may be less than 10% of a relative spectral power of any other peaks in the visible spectral output above 485 nm. At least one of the first or second caps may be adapted to couple with a tombstone associated with a troffer fixture thereby positioning the first or second cap in electrical communication with the tombstone.
In some embodiments, the driver circuit may be adapted to receive an electrical signal from at least one of the first and second caps. Additionally, the driver circuit may be adapted to operate the plurality of LED dies responsive to a received electrical signal. Furthermore, the LED lamp may additionally comprise a user input device positioned in electrical communication with at least one of the first and second caps. Furthermore, the user input device may be adapted to be a wall-mounted switch.
In some embodiments, the received electrical signal may be a signal received from a TRIAC device. Additionally, the LED lamp may further comprise a wireless communication device positioned in electrical communication with the driver circuit. The wireless communication device may be adapted to receive an input from a computerized device. The driver circuit may be adapted to operate the plurality of LED dies responsive to the input received by the wireless communication device. Additionally, the wireless communication device may be adapted to receive a wireless signal via a wireless communication method including at least one of Wi-Fi, Bluetooth, Zigbee, infrared (IR) data transmission, radio, visible light communication (VLC), cellular data service, and Near Field Communication (NFC).
In some embodiments, the driver circuit may be further adapted to drive the plurality of LED dies to emit a phase-shift light having a third spectral power distribution. Additionally, the driver circuit may be adapted to drive the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between 455 nm and 485 nm, that is greater than 125% of a relative spectral power of any other peaks in the visible spectral output above 485 nm in the phase-shift light.
Additionally, in some embodiments, the driver circuit may be further adapted to drive the plurality of LED dies to emit a phase-shift light having a third spectral power distribution, the phase-shift light being characterized by a characterized by a blue output intensity level, in a visible spectral output range of between 380 nm and 485 nm, that is within a range from 150% to 250% of a relative spectral power of any other peaks in the visible spectral output above 485 nm.
In some embodiments, the driver circuit may be adapted to drive the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between 380 nm and 485 nm, is within a range from 20% to 100% of a relative spectral power of any other peaks in the visible spectral output above 485 nm in the general illumination configuration.
In some embodiments, the plurality of LED dies may comprise a ratio of two red-orange LED dies to three cyan LED dies to three mint LED dies to three blue LED dies. In other embodiments, the plurality of LED dies may comprise a ratio of three cyan LED dies to three mint LED dies to two red-orange LED dies to one blue LED die.
Various aspects and alternative embodiments are described below.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the light spectra of conventional light sources in comparison to a predicted melatonin suppression action spectrum for polychromatic light.
FIG. 2 is a perspective view of an LED lamp in accordance with one embodiment presented herein.
FIG. 3 is an exploded view of the LED lamp of FIG. 2.
FIG. 4 is an exploded view of a portion of the LED lamp of FIG. 2.
FIG. 5 is an exploded view of a portion of the LED lamp of FIG. 2.
FIG. 6 is an exploded view of a portion of the LED lamp of FIG. 2.
FIG. 7 is an exploded view of a portion of the LED lamp of FIG. 2.
FIG. 8 is a schematic process diagram of an LED lamp in accordance with the present invention.
FIG. 9 illustrates a relative radiant power curve for a mint LED die used in one embodiment presented herein.
FIGS. 10A and 10B present color bin data for a mint LED die used III one embodiment presented herein.
FIG. 11 shows relative spectral power distributions for red, cyan, and blue LED dies that are used in one embodiment presented.
FIG. 12 shows a power spectral distribution of an LED lamp III a pre-sleep configuration, in accordance with another embodiment presented.
FIG. 13 shows a power spectral distribution of an LED lamp in a phase-shift configuration, in accordance with one embodiment presented.
FIG. 14 shows a power spectral distribution of an LED lamp in a general lighting configuration, in accordance with one embodiment presented.
FIG. 15 is an exploded view of an LED lamp in accordance with another embodiment presented.
FIG. 16 shows an alternative power spectral distribution for an LED lamp in a pre-sleep configuration.
FIG. 17 shows an alternative power spectral distribution for an LED lamp in a phase-shift configuration.
FIG. 18 shows an alternative power spectral distribution for an LED lamp in a general lighting configuration.
FIG. 19 shows a perspective view of an LED lamp according to an embodiment of the invention.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Those of ordinary skill in the art realize that the following descriptions of the embodiments of the present invention are illustrative and are not intended to be limiting in any way. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. Like numbers refer to like elements throughout.
Although the following detailed description contains many specifics for the purposes of illustration, anyone of ordinary skill in the art will appreciate that many variations and alterations to the following details are within the scope of the invention. Accordingly, the following embodiments of the invention are set forth without any loss of generality to, and without imposing limitations upon, the claimed invention.
In this detailed description of the present invention, a person skilled in the art should note that directional terms, such as “above,” “below,” “upper,” “lower,” and other like terms are used for the convenience of the reader in reference to the drawings. Also, a person skilled in the art should notice this description may contain other terminology to convey position, orientation, and direction without departing from the principles of the present invention.
Furthermore, in this detailed description, a person skilled in the art should note that quantitative qualifying terms such as “generally,” “substantially,” “mostly,” and other terms are used, in general, to mean that the referred to object, characteristic, or quality constitutes a majority of the subject of the reference. The meaning of any of these terms is dependent upon the context within which it is used, and the meaning may be expressly modified.
Throughout this disclosure, the present invention may be referred to as relating to luminaires, digital lighting, light sources, and light-emitting diodes (LEDs). Those skilled in the art will appreciate that this terminology is only illustrative and does not affect the scope of the invention. For instance, the present invention may just as easily relate to lasers or other digital lighting technologies. Additionally, a person of skill in the art will appreciate that the use of LEDs within this disclosure is not intended to be limited to any specific form of LED, and should be read to apply to light emitting semiconductors in general. Accordingly, skilled artisans should not view the following disclosure as limited to any particular light emitting semiconductor device, and should read the following disclosure broadly with respect to the same.
An embodiment of the invention, as shown and described by the various figures and accompanying text, provides an LED lamp with commercially acceptable color rendering properties, which can be tuned to produce varying light outputs. In one embodiment, the light output produces minimal melatonin suppression, and thus has a minimal effect on natural sleep patterns and other biological systems. The LED lamp may also be tuned to generate different levels of blue light, appropriate for the given circumstance, while maintaining good light quality and a high CRI in each case. The LED lamp may also be configured to “self-tune” itself to generate the appropriate light output spectrum, depending on factors such as the lamp's location, use, ambient environment, etc.
The light output states/configurations achievable by the LED lamps presented include: a pre-sleep configuration, a phase-shift configuration, and a general lighting configuration. In the pre-sleep configuration, the lamp generates a reduced level of blue light in order to provide an adequate working environment while significantly lessening the suppression of melatonin. The spectrum of light produced by the lamp in the pre-sleep configuration provides an environment appropriate for preparing for sleep while still maintaining light quality. In the phase-shifting configuration, the lamp generates an increased level of blue light, thereby greatly diminishing melatonin production. The spectrum of light produced by the lamp in this phase-shifting configuration provides an environment for shifting the phase of an individual's circadian rhythm or internal body clock. In the general lighting configuration, the lamp generates a normal level blue light, consistent with a typical light spectrum (e.g., daylight). In all states, however, the lamp maintains high visual qualities and CRI, in order to provide an adequate working environment.
In one embodiment, the ability to tune, or adjust, the light output is provided by employing a specific combination of LED dies of different colors, and driving the LED dies at various currents to achieve the desired light output. In one embodiment, the LED lamp employs a combination of red, blue, cyan, and mint LED dies, such that the combination of dies produces a desired light output, while maintaining high quality light and high CRI.
The following detailed description of the figures refers to the accompanying drawings that illustrate an exemplary embodiment of a tunable LED lamp for producing a biologically-adjusted light output. Other embodiments are possible. Modifications may be made to the embodiment described herein without departing from the spirit and scope of the present invention. Therefore, the following detailed description is not meant to be limiting.
FIG. 2 is a perspective view of an LED lamp (or bulb) 100 in accordance with one embodiment presented herein. In general, LED lamp 100 is appropriately designed to produce biologically-adjusted light, while still maintaining a commercially acceptable color temperature and commercially acceptable color rending properties.
The term “biologically-adjusted light” is intended to mean “a light that has been modified to manage biological effects on a user.” The term “biological effects” is intended to mean “any impact or change a light source has to a naturally occurring function or process.” Biological effects, for example, may include hormone secretion or suppression (e.g., melatonin suppression), changes to cellular function, stimulation or disruption of natural processes, cellular mutations or manipulations, etc.
As shown in FIG. 2, LED lamp 100 includes a base 110, a heat sink 120, and an optic 130. As will be described below, LED lamp 100 further includes one or more LED chips and dedicated circuitry
Base 110 is preferably an Edison-type screw-m shell. Base 110 is preferably formed of an electrically conductive material such as aluminum. In alternative embodiments, base 110 may be formed of other electrically conductive materials such as silver, copper, gold, conductive alloys, etc. Internal electrical leads (not shown) are attached to base 110 to serve as contacts for a standard light socket (not shown). Additionally, base 110 may be adapted to be any type of lamp base known in the art, including, but not limited to, bayonet, bi-post, bi-pin and wedge bases.
As known in the art, the durability of an LED chip is usually affected by temperature. As such, heat sink 120, and structures equivalent thereto, serves as means for dissipating heat away from one or more of the LED chips within LED lamp 100. In FIG. 2, heat sink 120 includes fins to increase the surface area of the heat sink. Alternatively, heat sink 120 may be formed of any configuration, size, or shape, with the general intention of drawings heat away from the LED chips within LED lamp 100. Heat sink 120 is preferably formed of a thermally conductive material such as aluminum, copper, steel, etc.
Optic 130 is provided to surround the LED chips within LED lamp 100. As used herein, the terms “surround” or “surrounding” are intended to mean partially or fully encapsulating. In other words, optic 130 surrounds the LED chips by partially or fully covering one or more LED chips such that light produced by one or more LED chips is transmitted through optic 130. In the embodiment shown, optic 130 takes a globular shape. Optic 130, however, may be formed of alternative forms, shapes, or sizes. In one embodiment, optic 130 serves as an optic diffusing element by incorporating diffusing technology, such as described in U.S. Pat. No. 7,319,293 (which is incorporated herein by reference in its entirety). In such an embodiment, optic 130, and structures equivalent thereto, serves as a means for defusing light from the LED chips. In alternative embodiments, optic 130 may be formed of a light diffusive plastic, may include a light diffusive coating, or may having diffusive particles attached or embedded therein.
In one embodiment, optic 130 includes a color filter applied thereto. The color filter may be on the interior or exterior surface of optic 130. The color filter is used to modify the light output from one or more of the LED chips. In one embodiment, the color filter is a ROSCOLUX #4530 CALCOLOR 30 YELLOW. In alternative embodiments, the color filter may be configured to have a total transmission of about 75%, a thickness of about 50 microns, and/or may be formed of a deep-dyed polyester film on a polyethylene terephthalate (PET) substrate.
In yet another embodiment, the color filter may be configured to have transmission percentages within +/−10%, at one or more wavelengths, in accordance with the following table:














Wavelength
Transmission (%)









360 380 400
66 64 49 30 22



420 440
10










FIG. 3 is an exploded view of LED lamp 100, illustrating internal components of the lamp. FIGS. 4-7 are exploded views of portions of LED lamp 100. FIGS. 3-7 also serve to illustrate how to assemble LED lamp 100. As shown, in addition to the components described above, LED lamp 100 also includes at least a housing 115, a printed circuit board (PCB) 117, one or more LED chips 200, a holder 125, spring wire connectors 127, and screws 129.
As described in more detail with reference to FIG. 8, PCB 117 includes dedicated circuitry, such as power supply 450, driver circuit 440, and output-select controller 445. The circuitry on PCB 117 and equivalents thereof serves as a means for driving the LED chips 200 (or individual LED dies) to produce a biologically-adjusted light output.
As used herein, the term “LED chip(s)” is meant to broadly include LED die(s), with or without packaging and reflectors, that may or may not be treated (e.g., with applied phosphors). In the embodiment shown, however, each LED chip 200 includes a plurality of LED dies. In one embodiment, LED chips 200 include an LED package comprising a plurality of LED dies, with at least two different colors, driven at varying currents to produce the desired light output and spectral power densities. Preferably, each LED chip 200 includes two red LED dies, three cyan LED dies, four mint LED dies, and three blue LED dies. FIG. 9 illustrates a relative radiant power curve for a mint LED die used in one embodiment presented herein. FIGS. 10A and 10B present color bin data for a mint LED die used in one embodiment presented herein. FIG. 11 shows relative spectral power distributions for red (or alternatively red-orange), cyan, and (two alternative) blue LED dies that are used in one embodiment presented (with alternative equivalent LED dies also being within the scope of the present invention). With this unique combinations of dies, together with the means for driving the LED chips, each of the above mentioned bio-effective states/configurations (e.g., pre-sleep, phase-shifting, and/or general lighting) can be obtained with good color rendering properties.
In one embodiment the tunable LED lamp operates in the pre-sleep configuration such that the radiant power emitted by the dies is in a ratio of: about 1 watt of radiant power generated by the mint LED dies, to about 0.5 watts of radiant power generated by the red-orange LED dies, to about 0.1 watts of radiant power generated by the cyan LED dies. In this embodiment the tunable LED lamp operates in the general lighting configuration such that the radiant power emitted by the dies is in a ratio about 1 watt of radiant power generated by the mint LED dies, to about 0.3 watts of radiant power generated by the red-orange LED dies, to about 0.4 watts of radiant power generated by the cyan LED dies, to about 0.2 watts of radiant power generated by the blue LED dies. In this embodiment, the tunable LED lamp operates in the phase-shift configuration such that the radiant power emitted by the dies is in a ratio of about 1 watt of radiant power generated by the mint LED dies, to about 0.1 watts of radiant power generated by the red-orange LED dies, to about 0.2 watts of radiant power generated by the cyan LED dies, to about 0.4 watts of radiant power generated by the blue LED dies.
In another embodiment, the tunable LED lamp operates in the pre-sleep configuration such that the radiant power emitted by the dies is in a ratio of: about 1 watt of radiant power generated by the mint LED dies, to about 0.8 watts of radiant power generated by the red-orange LED dies, to about 0.3 watts of radiant power generated by the cyan LED dies. In this embodiment, the tunable LED lamp operates in the general lighting configuration such that the radiant power emitted by the dies is in a ratio about 1 watt of radiant power generated by the mint LED dies, to about 0.2 watts of radiant power generated by the red-orange LED dies, to about 0.2 watts of radiant power generated by the blue LED dies. In this embodiment, the tunable LED lamp operates in the phase-shift configuration such that the radiant power emitted by the dies is in a ratio of about 1 watt of radiant power generated by the mint LED dies, to about 0.1 watts of watts of radiant power generated by the red-orange LED dies, to about 0.5 watts of radiant power generated by the blue LED dies.
For example, to achieve a pre-sleep configuration, driver circuit 440 may be configured to drive the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between about 380 nm and about 485 nm, is less than about 10% of a relative spectral power of any other peaks in the visible spectral output above about 485 nm. In one embodiment, driver circuit 440 drives the plurality of LED dies such that about 150 mA of current is delivered to four mint LED dies; about 360 mA of current is delivered to two red LED dies; and about 40 mA of current is delivered to three cyan LED dies. In another embodiment, wherein a color filter as described above is employed, the pre-sleep configuration is achieved by configuring driver circuit 440 to deliver about 510 MA of current to 4 mint LED dies.
To achieve a phase-shift configuration, driver circuit 440 may be configured to drive the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between about 455 nm and about 485 nm, is greater than about 125% (or greater than about 150%; or greater than about 200%) of a relative spectral power of any other peaks in the visible spectral output above about 485 nm. The color rendering index in the phase-shift configuration may be greater than 80. In one embodiment, driver circuit 440 drives the plurality of LED dies such that about 510 mA of current is delivered to the mint LED dies; about 180 mA of current is delivered to the red LED dies; about 40 mA of current is delivered to the cyan LED dies; and about 100 mA of current is delivered to the blue LED dies.
To achieve a general lighting configuration, driver circuit 440 may be configured to drive the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between about 380 nm and about 485 nm, is between about 100% to about 20% of a relative spectral power of any other peaks in the visible spectral output above about 485 nm. The color rendering index in the general lighting configuration may be greater than 85. In one embodiment, driver circuit 440 drives the plurality of LED dies such that about 450 mA of current is delivered to the mint LED dies; about 230 mA of current is delivered to the red LED dies; about 110 mA of current is delivered to the cyan LED dies; and about 60 mA of current is delivered to the blue LED dies.
In one embodiment, driver circuit 440 is configured to drive LED chips 200 with a ripple current at frequencies greater than 200 Hz. A ripple current at frequencies above 200 Hz is chosen to avoid biological effects that may be caused by ripple currents at frequencies below 200 Hz. For example, studies have shown that some individuals are sensitive to light flicker below 200 Hz, and in some instances experience aggravated headaches, seizures, etc
As shown in FIG. 4, base 110 is glued or crimped onto housing 115. PCB 117 is mounted within housing 115. Insulation and/or potting compound (not shown) may be used to secure PCB 117 within housing 115. Electrical leads on PCB 117 are coupled to base 110 to form the electrical input leads of LED lamp 100.
In some embodiments, base 110 may be adapted to facilitate the operation of the LED lamp based upon receiving an electrical signal from a light socket that base 110 may be attached to. For example, base 110 may be adapted to receive electrical signals from a three-way lamp, as is known in the art. Furthermore, driver circuit 440 may similarly be adapted to receive electrical signals from base 110 in such a fashion so as to use the electrical signals from the three-way lamp as an indication of which emitting configuration is to be emitted. The modes of operation of a three-way lamp are known in the art. Base 110 and driver circuit 440 may be adapted to cause the emission of the phase-shift configuration upon receiving a first electrical signal from a three-way lamp, the general illumination configuration upon receiving a second electrical signal from the three-way lamp, and the pre-sleep configuration upon receiving a third electrical signal from the three-way lamp.
More specifically, as is known in the art, base 110 may include a first terminal (not shown) and a second terminal (not shown), the first terminal being configured to electrically couple to a low-wattage contact of a three-way fixture, and the second terminal being configured to electrically couple to a medium wattage contact of a three-way fixture. Driver circuit 440 may be positioned in electrical communication with each of the first and second terminals of base 110. When base 110 receives an electric signal at the first terminal, but not at the second terminal, the driver circuit 440 may detect such and may cause the emission of light according to one of the phase-shift configuration, the general illumination configuration, and the pre-sleep configuration. When base 110 receives an electrical signal at the second terminal, but not at the first terminal, the driver circuit 440 may detect such and may cause the emission of light according to one of the phase-shift configuration, the general illumination configuration, and the pre-sleep configuration, but not the same configuration as when an electrical signal was detected at the first terminal and not the second. Finally, base 110 receives an electrical signal at both the first terminal and the second terminal, driver circuit 440 may detect such and may cause the emission of light according to one of the phase-shift configuration, the general illumination configuration, and the pre-sleep configuration, but not the same configuration as is emitted when an electrical signal is detected at only one of the first or second terminals of base 110.
Furthermore, in some embodiments, the driver circuit 440 may be configured to cause the emission of light according to any of the configurations as described hereinabove based upon the waveform of an electrical signal received by base 110 and detected by driver circuit 440. For example, in some embodiments, driver circuit 440 may be configured to cause the emission of light that is responsive to a TRIAC signal. A TRIAC signal is a method of manipulating the waveform of an AC signal that selectively “chops” the waveform such that only certain periods of the waveform within an angular range are transmitted to an electrical device, and is used in lighting.
Driver circuit 440 may be configured to cause the emission of light according to one of the various configurations of light responsive to varying ranges of TRIAC signals. A range of a TRIAC signal may be considered as a portion of a continuous, unaltered AC signal. A first TRIAG signal range may be a range from greater than about 0% to about 33% of an AC signal. This range may correspond to a percentage of the total angular measurement of a single cycle of the AC signal. Accordingly, where the single cycle of the AC signal is approximately 2π radians, the first range may be from greater than about 0 to about 0.67π radians. It is contemplated that angular measurement of the TRIAC signal is only one method of defining a range of a characteristic of the TRIAC signal. Other characteristics include, but are not limited to, phase angle, voltage, RMS voltage, and any other characteristic of an electric signal. Accordingly, the driver circuit 440 may include circuitry necessary to determine any of the phase angle, voltage, and RMS voltage of a received signal. The driver circuit 440 may be configured to detect the TRIAC signal and determine it falls within this range, and may further be configured to cause the emission of light according to one of the phase-shift configuration, the general illumination configuration, and the pre-sleep configuration. A second TRIAC signal range may be from about 33% to about 67% of an AC signal, which may correspond to a range from about 0.67π to about 1.33π radians. The driver circuit 440 may be configured to detect the TRIAC signal and determine it falls within this range, and may further be configured to cause the emission of light according to one of the phase-shift configuration, the general illumination configuration, and the pre-sleep configuration, but not the configuration that was emitted when the driver circuit determined the TRIAC signal was within the first TRIAC signal range. A third TRIAC signal range may be from about 67% to about 100% of an AC signal, which may correspond to a range from about 1.33π to about 2π radians. The driver circuit 440 may be configured to detect the TRIAC signal and determine it falls within this range, and may further be configured to cause the emission of light according to one of the phase-shift configuration, the general illumination configuration, and the pre-sleep configuration, but not the configuration that was emitted when the driver circuit determined the TRIAC signal was within either of the first TRIAC signal range or the second TRIAC signal range.
In another embodiment, a first TRIAC signal range may be from about 0% to about 25% of an AC signal, corresponding to within a range from about 0 to about 0.5π radians. Driver circuit 440 may be configured to detect the TRIAC signal and determine if it falls within this range, and may further be configured to not emit light. A second TRIAC signal range may be from about 25% to about 50% of an AC signal, corresponding to within a range from about 0.5π to about 1.0π radians. Driver circuit 440 may be configured to detect the TRIAC signal and determine if it falls within this range, and may further be configured to cause the emission of light according to one of the phase-shift configuration, the general illumination configuration, and the pre-sleep configuration. A third TRIAC signal range may be from about 50% to about 75% of an AC signal, corresponding to within a range from about 1.0π to about 1.5π radians. Driver circuit 440 may be configured to detect the TRIAC signal and determine if it falls within this range, and may further be configured to cause the emission of light according to one of the phase-shift configuration, the general illumination configuration, and the pre-sleep configuration, but not the configuration that was emitted when the driver circuit determined the TRIAC signal was within the second TRIAC signal range. A fourth TRIAC signal range may be from about 75% to about 100% of an AC signal, corresponding to a range from about 1.5π to about 2.0 radians. Driver circuit 440 may be configured to detect the TRIAC signal and determine if it falls within this range, and may further be configured to cause the emission of light according to one of the phase-shift configuration, the general illumination configuration, and the pre-sleep configuration, but not the configuration that was emitted when the driver circuit determined the TRIAC signal was within either of the second or third TRIAC signal ranges.
In order to enable the operation of an LED lamp 100 that is responsive to an electrical signal, such as a wireless signal or a TRIAC signal, it may be necessary to configure the power source for the LED lamp 100 to provide an electrical signal so as to control the operation of the LED lamp 100. Accordingly, in some embodiments, where the LED lamp 100 is electrically coupled to a lighting fixture that is controlled by a wall-mounted switch, or where the LED lamp 100 is directly electrically connected to a wall-mounted switch, the invention may further comprise a retrofit wall-mounted switch (not shown). In such embodiments, the retrofit wall-mounted switch may operate substantially as the output selection device and the user input device described herein. The retrofit wall-mounted switch may be configured to replace a standard wall switch for control of a light fixture, as is known in the art. The retrofit wall-mounted switch may be configured to generate or manipulate a signal so as to control the operation of the LED lamp 100. For example, in some embodiments, the retrofit wall-mounted switch may be configured to generate a wireless signal that may be received by the LED lamp 100 that may result in the operation of the LED lamp 100 as described hereinabove. Also, in some embodiments, the retrofit wall-mounted switch may be configured to manipulate a power source to which the retrofit wall-mounted switch is electrically coupled so as to generate a TRIAC signal, to which the LED lamp 100 may operate responsively to as described hereinabove. In such embodiments, the retrofit wall-mounted switch may be positioned electrically intermediate the power source and the LED lamp 100.
In some embodiments, base 110 may be configured to be a removably attachable member of LED lamp 100, defined as an intermediate base. In some other embodiments, an intermediate base may be included in addition the base 110. Intermediate base 110 may include structural elements and features facilitating the attachment of intermediate base 110 to a part of LED lamp 100. For example, intermediate base 110 may be adapted to cooperate with a feature or structure of housing 115 so as to removably attach intermediate base 110 thereto. For example, where intermediate base 110 is an Edison-type base having threading adapted to conform to standard threading for such bases, housing 115 may include a threaded section (not shown) configured to engage with the threads of intermediate base 110 so as to removable attach with intermediate base 110. Furthermore, each of intermediate base 110 and LED lamp 100 may include electrical contacts so as to electrically couple LED lamp 100 to intermediate base 110 when intermediate base 110 is attached. The size, position, and configuration of such electrical contacts may vary according to the method of attachment between LED lamp 100 and intermediate base 110.
Additionally, intermediate base 110 may include elements facilitating the transitioning of LED chips 200 between the various configurations, i.e. pre-sleep, phase shift, and general illuminating configurations. For example, in some embodiments, intermediate base 110 may include a user input device (not shown) adapted to receive an input from a user. The input from the user may cause intermediate base 110 to interact with at least one of driver circuit 440 and a power circuit of the LED lamp 100 so as to cause the LED chips 200 to emit light according to any of the configurations recited herein.
In some embodiments, the user input may cause the LED lamp 100 to transition from the present emitting configuration to a selected emitting configuration, or to cease emitting light. In some embodiments, the user input may cause the LED lamp 100 to progress from one emitting configuration to another emitting configuration according to a defined progression. An example of such a progression may be, from an initial state of not emitting light, to emitting the phase-shift configuration, to emitting the general illumination configuration, to emitting the pre-sleep configuration, to ceasing illumination. Such a progression is exemplary only, and any combination and permutation of the various emitting configurations are contemplated and included within the scope of the invention. The base 110 may include circuitry necessary to receive the input from the user and to communicate electrically with the various elements of the LED lamp 100 to achieve such function.
In some embodiments, the user input device may be a device that is physically accessible by a user when the base 110 is attached to the LED lamp 100 and when the LED lamp 100 is installed in a lighting fixture. For example, the user input device may be a lamp turn knob operatively connected to circuitry comprised by the base 110 to affect the transitioning described hereinabove. A lamp turn knob is an exemplary embodiment only, and any other structure or device capable of receiving an input from a user based on electrical and/or mechanical manipulation or operation by the user is contemplated and included within the scope of the invention. In some embodiments, the user input device may be an electronic communication device including a wireless communication device configured to receive a wireless signal from the user as the input. Such user input devices may be adapted to receive a user input in the form of an infrared signal, a visible light communication (VLC) signal, radio signal, such as Wi-Fi, Bluetooth, Zigbee, cellular data signals, Near Field Communication (NFC) signal, and any other wireless communication standard or method known in the art. Additionally, in some embodiments, the user input device may be adapted to receive an electronic signal from the user via a wired connection, including, but not limited to, Ethernet, universal serial bus (USB), and the like. Furthermore, where the user input device is adapted to establish an Ethernet connection, the user input device may be adapted to receive power from the Ethernet connection, conforming to Power-over-Ethernet (PoE) standards. In such embodiments, the power received by the user input device may provide power to the LED lamp 100 enabling its operation.
In some embodiments, it is contemplated that any of the lighting devices as described herein may be integrally formed with a lighting fixture, where the LED lamp 100 is not removably attachable to the lighting fixture. More specifically, in some embodiments, those aspects of the lighting devices described herein that are included to permit the attachability of the lighting device to a separately-produced lighting fixture may be excluded, and those aspects directed to the function of emitting light according to the various lighting configurations as described herein may be included. For example, in the present embodiment, the base 110 may be excluded, and the driver circuit 440 may be directly electrically coupled to an external power source or to an electrical conduit thereto. Furthermore, the geometric configuration of optic 130, heat sink 120, LED chips 200, and all other elements of the LED lamp 100 may be adapted to facilitate a desired configuration of an integrally-formed lighting fixture.
As shown in FIG. 5, heat sink 120 is disposed about housing 115. As shown in FIG. 6, two LED chips 200 are mounted onto a support surface (or directly to heat sink 120), and maintained in place by holder 125. While two LED chips 200 are shown, alternative embodiments may include any number of LED chips (i.e., one or more), or any number of LED dies individually mounted. Screws 129 are used to secure holder 125 to heat sink 120. Screws 129 may be any screws known in the art. Spring wire connectors 127 are used to connect LED chips 200 to the driver circuit 440 on PCB 117. In an alternative embodiment, LED chips 200 (with or without packaging) may be attached directly to heat sink 120 without the use of holder 125, screws 129, or connectors 127. As shown in FIG. 7, optic 130 is then mounted on and attached to heat sink 120.
FIG. 8 is a schematic process diagram of an LED lamp in accordance with the present invention. FIG. 8 also serves a depiction of the functional components mounted on PCB 117, or otherwise associated with LED lamp 100. In practice, a power supply 450 is used to provide power to driver circuit 440. Power supply 450 may, for example, convert AC power to DC power, for driving the LED dies. Driver circuit 440 receives power input from power supply 450, and directional input from output-select controller 445. In turn, driver circuit 440 provides the appropriate current supply to drive the LED dies in accordance with the desired spectral output. Controller 445 therefore serves to control the driving of LEDs 200, and may control light output based on factors such as: time of day, ambient light, real time input, temperature, optical output, location of lamp, etc.
Variations in temperature during operation can cause a spectral shift of individual dies. In an embodiment, a photo-sensor 860 is included to monitor the light output of the LEDs 200 to insure consistency and uniformity. Monitoring the output of LEDs 200 allows for real time feedback and control of each die to maintain the desired output spectrum. Photo-sensor 860 may also be used to identify the ambient light conditions. Photo-sensor 860 thus provides an input to controller 445.
In another embodiment, a thermal sensor 855 is used to measure the temperature of the LED dies and/or board supporting the LED dies. Because the light output of the dies is a known function of temperature, the measured temperature can be used to determine the light output of each die. Thermal sensor 855 may also be used to measure the ambient temperature conditions. Thermal sensor 855 thus provides another input to controller 445.
In another embodiment, a GPS chip 870 and/or clock 875 is included and interfaced with controller 445. Because lamps are shipped around the world to their end location, the ability to determine the expected/actual ambient light, daily light cycle, and seasonal light cycle variations is important in any lamp that may generate light to stimulate or alter circadian rhythms. GPS chip 870 and/or clock 875 provide inputs into controller 445 such that the time of day, seasonality, and other factors can be taken into account by controller 445 to control the lamp output accordingly. For example, by knowing the time of day based on location, the pre-sleep spectrum of the lamp can be generated during the later hours of the day.
In still another embodiment, a user-interface 865 is provided to allow a user to select the desired configuration. User-interface 865 may be in the form of a knob, switch, digital input, or equivalent means. As such, user-interface 865 provides an additional input to controller 445.
In one embodiment, the pre-sleep configuration spectrum includes a portion of the spectrum that is reduced (e.g., notched/troughed) in intensity. This trough is centered at about 470 nm (or alternatively between about 470-480 nm, between about 460-480 nm, between about 470-490 nm, or between about 460-490 nm). Such wavelength ranges may be the most important contributor to, and most effective at, suppressing melatonin. Thus minimizing exposure in such wavelength bands during pre-sleep phase will be efficacious. In one embodiment, the notching of the pre-sleep spectrum is obtained using a phosphor-coated mint LED having a specific output spectrum to accomplish the notch in the pre-sleep spectrum. The mint LED itself may include a notch/trough with a minimum in the 470-480 nm (or 460-490 nm range), and may be characterized by a maximum intensity in these wavelength ranges as a fractional percent of the peak intensity of the mint LED (e.g., the maximum of 470-480 emission is less than about 2.5% of the peak intensity; the max between about 460-490 nm is less than about 5% of the peak intensity).
With reference again to FIG. 9, illustrated is a relative radiant power curve for a mint LED die used in one embodiment presented. As used herein, the terms “mint LED” or “mint LED die” or “mint die” should be construed to include any LED source, LED chip, LED die (with or without photo-conversion material on the die), or any equivalent light source that is configured or capable of producing the relative radiant power curve shown in FIG. 9, or a relative radiant power curve equivalent thereto. Of particular interest to the shown relative radiant power curve is the spectral “notch” between about 460-490 nm, and more specifically between at about 470-480 nm. Said spectral notch provides a relative intensity, with respect to the peak intensity, that allows the combination of LED dies (or equivalent light sources) to achieve their desired results (i.e., the desired output configuration). In one embodiment, the maximum intensity of the mint LED between about 460-490 nm is less than about 5% of the peak intensity. In alternative embodiments the maximum intensity of the mint LED between about 460490 nm is less than about 7.5%, or about 10%, or about 15%, or about 20% of the peak intensity. Further, in one embodiment, the maximum intensity of the mint LED between about 470-480 nm is less than about 2.5% of the peak intensity. In alternative embodiments, the maximum intensity of the mint LED between about 470-480 nm is less than about 3.5%, 5%, 10%, or 20% of the peak intensity.
FIGS. 12, 13, and 14 show the power spectral distributions corresponding respectively to the pre-sleep, phase-shift, and general illumination configurations of the LED lamp in accordance with one embodiment of the invention. The LED lamp in this embodiment comprises an LED board with a ratio of Cyan, Mint, Red, and Royal Blue dies of 3:3:2:1 respectively. The spectral output of the lamp according to each configuration is adjusted by generating radiant fluxes from multiple dies as described below.
FIG. 12 shows a power spectral distribution of an LED lamp III a pre-sleep configuration, in accordance with another embodiment presented. The pre-sleep configuration shown in FIG. 13 is produced by an array of LED dies in the 3:3:2:1 ratio, driven as follows: (1) three cyan LEDs driven at 7.65V, 66 mA, 0.16679 radiant flux; (2) three mint LEDs driven parallel at 11.13V, 951 mA, 1.8774 radiant flux; (3) two red-orange LEDs driven at 4.375V, 998 mA, 0.96199 radiant flux; and (4) one royal blue LED driven at 2.582V, 30 mA, 0.0038584 radiant flux. The total luminous flux is 1.024e+003 1 m. The total radiant flux is 3.023ge+000 W. The dominant wavelength is 580.3 nm. The general CRI is 87.30. The color temperature is 2871 K. The 1931 Coordinates (2°) are x: 0.4649, y: 0.4429. The luminous power per radiant watt is 338 lumens per radiant watt.
FIG. 13 shows a power spectral distribution of an LED lamp in a phase-shift configuration, in accordance with one embodiment presented. The phase-shift configuration shown in FIG. 14 is produced by an array of LED dies in the 3:3:2:1 ratio, driven as follows: (1) three cyan LEDs driven at 8.19V, 235 mA, 0.47233 radiant flux; (2) three mint LEDs driven parallel at 11.14V, 950 mA, 1.9047 radiant flux; (3) two red-orange LEDs driven at 3.745V, 147 mA, 0.1845 radiant flux; and (4) one royal blue LED driven at 2.802V, 525 mA, 0.69093 radiant flux. The total luminous flux is 9.87ge+002 1 m. The total radiant flux is 3.2138e+000 W. The dominant wavelength is 495.6 nm. The peak wavelength is 449.7 nm. The general CRI is 87.42. The color temperature is 6,599 K. The 1931 Coordinates (2°) are x: 0.3092, y: 0.3406. The luminous power per radiant watt is 307 lumens per radiant watt.
In an alternative embodiment, in the phase-shift configuration, the intensity levels of blue component in the 455 nm to 485 nm range is preferably greater than about 125% of the relative spectral power of any other peaks in the visible light spectrum higher than 485 nm. In alternative embodiments, the blue component in the 455 nm to 485 nm range may be is preferably greater than about 150%; or about 175%; or about 200%; or about 250%; or about 300% of the relative spectral power of any other peaks in the visible light spectrum higher than 485 nm. The color rendering index is preferably greater than 80. By varying the radiant fluxes of one or more of the dies, for example by varying the current drawn by the dies, the intensity of the blue component relative to other spectral peaks greater than 485 nm may be adjusted to the desired level.
FIG. 14 shows a power spectral distribution of an LED lamp in a general lighting configuration, in accordance with one embodiment presented. The general lighting configuration shown in FIG. 15 is produced by an array of LED dies in the 3::3:2:1 ratio, driven as follows: (1) three cyan LEDs driven at 8.22V, 211 mA, 0.44507 radiant flux; (2) three mint LEDs driven parallel at 10.06V, 499 mA, 1.1499 radiant flux; (3) two red-orange LEDs driven at 3.902V, 254 mA, 0.34343 radiant flux; and (4) one blue LED driven at 2.712V, 190 mA, 0.27280 radiant flux. The total luminous flux is 7.192e+002 1 m. The total radiant flux is 2.2248e+000 W. The dominant wavelength is 566.2 nm. The peak wavelength is 625.9 nm. The general CRI is 93.67. The color temperature is 4897 K. The 1931 Coordinates (2°) are x: 0.3516, y: 0.3874. The luminous power per radiant watt is 323 lumens per radiant watt.
In an alternative embodiment, in the general illumination configuration, the intensity levels of blue component in the 380 nm to 485 nm range is preferably about 100% of the relative spectral power of any other peaks in the visible light spectrum higher than 485 nm. In alternative embodiments, the intensity levels of blue component in the 380 nm to 485 nm range is preferably less than about 100%; or less than about 90%; or less than about 80%; or between about 20% to about 100% of the relative spectral power of any other peaks in the visible light spectrum higher than 485 nm. The color rendering index is preferably greater than 85.
FIG. 15 is an exploded view of an LED lamp in accordance with another embodiment presented. FIG. 15 shows an additional form factor in which the present invention may be applied. For example, FIG. 15 shows a lamp 1600 having an array of LEDs 1610. The LEDs 1610 may be provided in the 3:3:2:1 ratio of cyan:mint:red-orange:blue, as described above.
In another embodiment, the LEDs 1610 may be provided in a 3:3:2:3 ratio of cyan:mint:red:blue, as described above. The LEDs are mounted on a support frame 1620, which may serve as a heat-sink. LED circuitry 1630 is used to drive the LEDs 1610 with appropriate drive currents to achieve two or more output configurations (e.g., pre-sleep, phase-shift, and general lighting configurations). An output-select controller 1640 (and associated knob) are provided to allow an end-user to select the desired output configuration. An optic 1650 is provided in front of the LEDs 1610 to provide diffusive effects. The form factor may be completed by fastening the components with means such as screws and/or nuts and bolts, as shown.
Additional Embodiments
FIGS. 16, 17, and 18 show the power spectral distributions corresponding respectively to the pre-sleep, phase-shift, and general illumination configurations of the LED lamp in accordance with one embodiment of the invention. The LED lamp in this embodiment comprises an LED board with a ratio of Cyan, Mint, Red, and Blue dies of 3:3:2:3 respectively. The spectral output of the lamp according to each configuration is adjusted by generating radiant fluxes from multiple dies as described below.
FIG. 16 shows a power spectral distribution of an LED lamp III a pre-sleep configuration, in accordance with another embodiment presented. The pre-sleep configuration shown in FIG. 13 is produced by an array of LED dies in the 3:3:2:3 ratio, driven as follows: (1) three cyan LEDs driven at 7.83V, 91 mA, to generate 0.2048 radiant watts; (2) three mint LEDs driven parallel at 9.42V, 288 mA, 0.6345 radiant watts; (3) two red-orange LEDs driven at 4.077V, 490 mA, 0.5434 radiant watts. The dominant wavelength is 581.4 nm. The general CRI is 71. The color temperature is 2719 K. The luminous power per radiant watt is 331 lumens per radiant watt. The efficacy is 91 lumens per watt.
FIG. 17 shows a power spectral distribution of an LED lamp in a phase-shift configuration, in accordance with another embodiment presented. The phase-shift configuration shown in FIG. 18 is produced by an array of LED dies in the 3:3:2:3 ratio, driven as follows: (1) three mint LEDs driven parallel at 11.27V, 988 mA, 1.679 radiant watts; (2) two red-orange LEDs driven at 3.78V, 180 mA, 1.971 radiant, and (3) three blue LEDs driven at 9.07V, 296 mA, 0.8719 radiant watts. The dominant wavelength is 476.9 nm. The general CRI is 88. The color temperature is 6235 K. The luminous power per radiant watt is 298 lumens per radiant watt. The efficacy is 63 lumens per watt.
FIG. 18 shows a power spectral distribution of an LED lamp in a general lighting configuration, in accordance with another embodiment presented. The general lighting configuration shown in FIG. 19 is produced by an array of LED dies in the 3:3:2:3 ratio, driven as follows: (1) three cyan LEDs driven at 8.16V, 218 mA, to generate 0.4332 radiant watts; (2) three mint LEDs driven parallel at 11.23V, 972 mA, 1.869 radiant watts; (3) two red-orange LEDs driven at 3.89V, 295 mA, 0.3520 radiant watts. The dominant wavelength is 565.6 nm. The general CRI is 90. The color temperature is 4828 K. The luminous power per radiant watt is 335 lumens per radiant watt. The efficacy is 68 lumens per watt
In another embodiment, there is provided a tunable LED lamp for producing a biologically-adjusted light output with a color rendering index above 70. The LED lamp comprises: a base; a housing attached to the base; a power circuit disposed within the housing and having electrical leads attached to the base; a driver circuit disposed within the housing and electrically coupled to the power circuit; and a heat sink disposed about the housing. The LED lamp further comprises: a plurality of LED dies mounted on a support coupled to the housing, wherein each of the plurality of LED dies is electrically coupled to and driven by the driver circuit. The plurality of LED dies includes two red LED dies, three cyan LED dies, four mint LED dies, and three blue LED dies. The LED lamp further comprises: an output-select controller electrically coupled to the driver circuit to program the driver circuit to drive the LED dies in one of a plurality of light output configurations. The plurality of light output configurations includes a pre-sleep configuration, a phase-shift configuration, and a general lighting configuration.
The output-select controller may include a user-input interface allowing a user to select the light output configuration. The LED lamp my further include an input sensor electrically coupled to the output-select controller to provide an input variable for consideration in the selection of the light output configuration. The input sensor may be a thermal sensor, a photo-sensor, and/or a GPS chip. The input variable may be selected from the group consisting of: an ambient temperature, a support temperature, an LED die temperature, a housing temperature, the light output produced by the lamp, an ambient light, a daily light cycle, a location of the lamp, an expected ambient light, a seasonal light cycle variation, a time of day, and any combinations and/or equivalents thereof.
In the pre-sleep configuration, the driver circuit drives the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between about 380 nm and about 485 nm, is less than about 10% of a relative spectral power of any other peaks in the visible spectral output above about 485 nm. For example, the driver circuit may drive the plurality of LED dies such that about 150 mA of current is delivered to the mint LED dies; about 360 mA of current is delivered to the red LED dies; and about 40 mA of current is delivered to the cyan LED dies.
In the phase-shift configuration, the driver circuit drives the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between about 455 nm and about 485 nm, is greater than about 125% of a relative spectral power of any other peaks in the visible spectral output above about 485 nm. The color rendering index in the phase-shift configuration may be greater than 80. For example, the driver circuit may drive the plurality of LED dies such that about 510 mA of current is delivered to the mint LED dies; about 180 mA of current is delivered to the red LED dies; about 40 mA of current is delivered to the cyan LED dies; and about 100 mA of current is delivered to the blue LED dies.
In the general lighting configuration, the driver circuit drives the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between about 380 nm and about 485 nm, is between about 100% to about 20% of a relative spectral power of any other peaks in the visible spectral output above about 485 nm. The color rendering index in the general lighting configuration may be greater than 85. For example, the driver circuit may drive the plurality of LED dies such that about 450 mA of current is delivered to the mint LED dies; about 230 mA of current is delivered to the red LED dies; about 110 mA of current is delivered to the cyan LED dies; and about 60 mA of current is delivered to the blue LED dies.
In another embodiment, there is provided an LED lamp, comprising: a housing; a driver circuit disposed within the housing and configured to electrically couple to a power source; and a plurality of LED dies mounted on a support coupled to the housing, wherein each of the plurality of LED dies is electrically coupled to and driven by the driver circuit. The LED lamp further includes an output-select controller electrically coupled to the driver circuit to program the driver circuit to drive the LED dies in one of a plurality of light output configurations. The output-select controller may also include a user-input interface allowing a user to select the light output configuration.
The plurality of light output configurations includes a pre-sleep configuration and a general lighting configuration. The plurality of light output configurations may further include a phase-shift configuration. The plurality of LED dies may include red LED dies, cyan LED dies, mint LED dies, and blue LED dies. The ratio of red LED dies to cyan LED dies to mint LED dies to blue LED dies of 2:3:4:3, respectively. The LED lamp may be tunable to produce a biologically-adjusted light output with a color rendering index above 70.
The LED lamp may further comprise an input sensor electrically coupled to the output-select controller to provide an input variable for consideration in the selection of the light output configuration. The input sensor may be a thermal sensor, a photo-sensor, and/or a GPS chip. The input variable may be selected from the group consisting of: an ambient temperature, a support temperature, an LED die temperature, a housing temperature, the light output produced by the lamp, an ambient light, a daily light cycle, a location of the lamp, an expected ambient light, a seasonal light cycle variation, a time of day, and any combinations and/or equivalents thereof.
In the pre-sleep configuration, the driver circuit drives the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between about 380 nm and about 485 nm, is less than about 10% of a relative spectral power of any other peaks in the visible spectral output above about 485 nm. For example, the driver circuit may drive the plurality of LED dies such that about 150 mA of current is delivered to the mint LED dies; about 360 mA of current is delivered to the red LED dies; and about 40 mA of current is delivered to the cyan LED dies.
In the phase-shift configuration, the driver circuit drives the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between about 455 nm and about 485 nm, is greater than about 125% (or greater than about 150%; or greater than about 200%) of a relative spectral power of any other peaks in the visible spectral output above about 485 nm. The color rendering index in the phase-shift configuration may be greater than 80. For example, the driver circuit may drive the plurality of LED dies such that about 510 mA of current is delivered to the mint LED dies; about 180 mA of current is delivered to the red LED dies; about 40 mA of current is delivered to the cyan LED dies; and about 100 mA of current is delivered to the blue LED dies
In the general lighting configuration, the driver circuit drives the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between about 380 nm and about 485 nm, is between about 100% to about 20% of a relative spectral power of any other peaks in the visible spectral output above about 485 nm. The color rendering index in the general lighting configuration may be greater than 85. For example, the driver circuit may drive the plurality of LED dies such that about 450 mA of current is delivered to the mint LED dies; about 230 mA of current is delivered to the red LED dies; about 110 mA of current is delivered to the cyan LED dies; and about 60 mA of current is delivered to the blue LED dies.
In another embodiment, there is provided a tunable LED lamp for producing a biologically-adjusted light output with a color rendering index above 70, comprising: a base; a housing attached to the base; a power circuit disposed within the housing and having electrical leads attached to the base; a driver circuit disposed within the housing and electrically coupled to the power circuit; a heat sink disposed about the housing; a plurality of LED dies mounted on a support coupled to the housing, wherein each of the plurality of LED dies is electrically coupled to and driven by the driver circuit, and wherein the plurality of LED dies includes a ratio of two red-orange LED dies to three cyan LED dies to three mint LED dies to one blue LED dies; and an output-select controller electrically coupled to the driver circuit to program the driver circuit to drive the LED dies in one of a plurality of light output configurations, wherein the plurality of light output configurations includes a pre-sleep configuration, a phase-shift configuration, and a general lighting configuration. In the pre-sleep configuration, the driver circuit may drive the plurality of LED dies such that about 950 mA of current is delivered to the mint LED dies, about 1,000 mA of current is delivered to the red-orange LED dies, about 65 mA of current is delivered to the cyan LED dies; and about 30 mA of current is delivered to the blue LED dies. In the phase-shift configuration, the driver circuit may drive the plurality of LED dies such that about 950 mA of current is delivered to the mint LED dies, about 150 mA of current is delivered to the red-orange LED dies, about 235 mA of current is delivered to the cyan LED dies, and about 525 mA of current is delivered to the blue LED dies. In the general lighting configuration, the driver circuit may drive the plurality of LED dies such that about 500 mA of current is delivered to the mint LED dies, about 250 mA of current is delivered to the red-orange LED dies, about 210 mA of current is delivered to the cyan LED dies, and about 190 mA of current is delivered to the blue LED dies. In other embodiments, alternative currents may be delivered to vary the radiant fluxes and achieve the desired spectral output.
In yet another embodiment, there is provided a method of manufacturing a tunable LED lamp for producing a biologically-adjusted light output with a color rendering index above 70. The method comprises: (a) attaching a base to a housing; (b) electrically coupling leads of a power circuit within the housing to the base; (c) electrically coupling a driver circuit disposed within the housing to the power circuit; (d) mounting a plurality of LED dies on a support coupled to the housing such that each of the plurality of LED dies is electrically coupled to and driven by the driver circuit, and wherein the plurality of LED dies includes two red LED dies, three cyan LED dies, four mint LED dies, and three blue LED dies; and (e) configuring the driver circuit to drive the LED dies in one of a plurality of light output configurations, wherein the plurality of light output configurations includes a pre-sleep configuration, a phase-shift configuration, and a general lighting configuration.
The method may further comprise: (f) configuring the driver circuit to drive the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between about 380 nm and about 485 nm, is less than about 10% of a relative spectral power of any other peaks in the visible spectral output above about 485 nm; (g) configuring the driver circuit to drive the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between about 455 nm and about 485 nm, is greater than about 125% of a relative spectral power of any other peaks in the visible spectral output above about 485 nm; and/or (h) configuring the driver circuit to drive the plurality of LED dies such that a blue output intensity level, in a visible spectral output range of between about 380 nm and about 485 nm, is between about 100% to about 20% of a relative spectral power of any other peaks in the visible spectral output above about 485 nm.
The method may further comprise: (i) configuring the driver circuit to drive the plurality of LED dies such that about 150 mA of current is delivered to the mint LED dies, about 360 mA of current is delivered to the red LED dies, and about 40 mA of current is delivered to the cyan LED dies; (j) configuring the driver circuit to drive the plurality of LED dies such that about 510 mA of current is delivered to the mint LED dies, about 180 mA of current is delivered to the red LED dies, about 40 mA of current is delivered to the cyan LED dies, and about 100 mA of current is delivered to the blue LED dies; and/or (k) configuring the driver circuit to drive the plurality of LED dies such that about 450 mA of current is delivered to the mint LED dies, about 230 mA of current is delivered to the red LED dies, about 110 mA of current is delivered to the cyan LED dies, and about 60 mA of current is delivered to the blue LED dies.
In another embodiment, there is provided an LED lamp, comprising: a housing; a driver circuit disposed within the housing and configured to electrically couple to a power source; a plurality of LED dies mounted on a support coupled to the housing, wherein each of the plurality of LED dies is electrically coupled to and driven by the driver circuit; and an output-select controller electrically coupled to the driver circuit to program the driver circuit to drive the LED dies in one of a plurality of light output configurations, wherein the plurality of light output configurations includes a pre-sleep configuration and a general lighting configuration. The plurality of LED dies includes red-orange LED dies, cyan LED dies, mint LED dies, and blue LED dies. The plurality of LED dies includes a ratio of red-orange LED dies to cyan LED dies to mint LED dies to blue LED dies of 2:3:3:1, respectively.
In another embodiment, there is provided a method of manufacturing a tunable LED lamp for producing a biologically-adjusted light output with a color rendering index above 70, comprising: attaching a base to a housing; electrically coupling leads of a power circuit within the housing to the base; electrically coupling a driver circuit disposed within the housing to the power circuit; mounting a plurality of LED dies on a support coupled to the housing such that each of the plurality of LED dies is electrically coupled to and driven by the driver circuit, and wherein the plurality of LED dies includes two red-orange LED dies, three cyan LED dies, three mint LED dies, and one blue LED dies; and configuring the driver circuit to drive the LED dies in one of a plurality of light output configurations, wherein the plurality of light output configurations includes a pre-sleep configuration, a phase-shift configuration, and a general lighting configuration. In the pre-sleep configuration the method may further comprises configuring the driver circuit to drive the plurality of LED dies such that about 950 mA of current is delivered to the mint LED dies, about 1,000 mA of current is delivered to the red-orange LED dies, about 65 mA of current is delivered to the cyan LED dies, and about 30 mA of current is delivered to the blue LED dies. In the phase-shift configuration the method may further comprise: configuring the driver circuit to drive the plurality of LED dies such that about 950 mA of current is delivered to the mint LED dies, about 150 mA of current is delivered to the red LED dies, about 235 mA of current is delivered to the cyan LED dies, and about 525 mA of current is delivered to the blue LED dies. In the general lighting configuration the method may further comprise: configuring the driver circuit to drive the plurality of LED dies such that about 500 mA of current is delivered to the mint LED dies, about 250 mA of current is delivered to the red LED dies, about 210 mA of current is delivered to the cyan LED dies, and about 190 mA of current is delivered to the blue LED dies.
Referring now to FIG. 19, another embodiment of the present invention is depicted. In the present embodiment, a lighting device 500 is depicted. The lighting device 500 may be configured to emit light having a spectral power distribution as described hereinabove, including a phase-shift configuration, a general illumination configuration, and a pre-sleep configuration. The lighting device 500 may be configured to conform to a troffer configuration as is known in the art. In the present embodiment, the lighting device 500 has a generally elongate shape. In some other embodiments, other shapes and configurations may be utilized, including helixes, u-shapes, and any other configuration as is known in the art, including, but not limited to, T series bulb configurations.
The lighting device 500 may comprise a housing 502. The housing 502 may be configured to generally define the shape of the lighting device 500. The housing 502 may be configured to be at least one of transparent a translucent. Moreover, the housing 502 may be configured to be at least one of transparent and translucent in a first section, and generally opaque in a second section. Accordingly, in some embodiments, the housing 502 may be formed of two or more materials having the above-mentioned optical characteristics. Furthermore, the housing 502 may be configured to be generally hollow in construction, defining an internal chamber 504. The internal chamber 504 may be configured to permit the positioning of various elements of the lighting device 500 therein, as will be discussed in greater detail. In the present embodiment, the housing 502 is configured to have a generally tubular, cylindrical configuration with a hollow interior.
In some embodiments, the housing 502 may comprise a color conversion layer (not shown). The color conversion layer may be positioned generally adjacent to an inside surface of the housing 502. The color conversion layer may be configured to receive a source light within a source wavelength range and to emit a converted light within a converted wavelength range. Moreover, in some embodiments, the housing 502 may comprise a filter material, such as a color filter as described hereinabove.
In some embodiments, the housing 502 may include one or more caps 506. The caps 506 may be positioned at respective ends of the housing 502. In the present embodiment, the housing 502 may include a first cap 506′ at a first end and a second cap 506′′ at a second end. Additionally, the caps may include one or more electrical contacts 508. The electrical contacts 508 may be configured so as to position the lighting device 500 in electrical communication with a power supply. The electrical contacts may be configured to conform to a standard design for a light fixture. In the present embodiment, the electrical contacts 508 may be configured to conform to a troffer fixture having a bi-pin configuration. Moreover, each of the caps 506 may be configured to position the electrical contacts 508 in electrical communication with a tombstone of a troffer fixture. In addition to the electrical contacts 508 being configurable so as to electrically couple to an external lighting fixture, the electrical contacts 508 may also be configured to electrically couple with an electrical device positioned within the internal chamber 504. As such, the electrical contacts 508 may be configured so as to be accessible, either physically or electrically, or both, from within the internal chamber 504. Accordingly, the electrical contacts 508 may comprise internal contacts 508′ and external contacts 508′′. The external contacts 508′′ may be configured to couple to a tombstone of a troffer fixture, as is known in the art.
Additionally, in some embodiments, the electrical contacts 508 may be configured to as to provide structural support to the lighting device 500. More specifically, the electrical contacts 508 may be configured to permit the lighting device 500 to be carried by a troffer fixture when the lighting device 500 is installed within the troffer fixture. More specifically, the electrical contacts 508 may be configured to couple to a tombstone of the troffer fixture when the lighting device 500 is installed within the troffer fixture. Accordingly, the electrical contacts 508 may be formed of material that, along to being sufficiently electrical conductive so as to deliver electricity to the various electrical components of the lighting device 500, the electrical contacts 508 may also be formed of a material that may have imparted thereon the forces of installing and carrying the lighting device without bending, deflecting, or otherwise deforming so as to prevent or inhibit the installation or operation of the lighting device 500 into a fixture. Furthermore, the caps 506 may similarly be configured so as to withstand such forces.
The lighting device 500 may further include a driver circuit 510. The driver circuit may be substantially as described hereinabove, enabling the emission of light having desired spectral power distributions. The driver circuit 510 may be configured to be electrically coupled to electrical contacts 508 of either of the first or second caps 506′, 506′′. More specifically, the driver circuit 510 may be electrically coupled to internal contacts 508′.
In some embodiments, the lighting device 500 may comprise a power circuit (not shown). The power circuit may be configured to be electrically coupled to the electrical contacts 508 of either of the first or second caps 506′, 506′′ and the driver circuit 510 such that the power circuit is electrically intermediate the electrical contacts 508 and the driver circuit 510. The power circuit may be configured to condition electricity received from the electrical contacts so as to be usable by the driver circuit 510. However, in some embodiments, such as the present embodiment, the power circuit may be included in and integral with the driver circuit 510, such that they are positioned within the same printed circuit board. In other embodiments, the power circuit may be a separate and distinct element of the lighting device 500.
The lighting device 500 may further include a plurality of LED dies 520. The plurality of LED dies 520 may be positioned within the internal chamber 504 and electrically coupled to the driver circuit 510. Additionally, as in the present embodiment, the plurality of LED dies 520 may be electrically coupled to the electrical contacts 508 of one of the first and second caps 506′, 506′′. In the present embodiment, the plurality of LED dies 520 are electrically coupled to internal contacts 508′ of the first cap 506′. The plurality of LED dies 520 may be positioned so as to emit light that propagates through the housing 502 into the environment surrounding the lighting device 500. In some embodiments, the plurality of LED dies 520 may be positioned so as to emit light that passes through the transparent or translucent sections of the housing 502 and is generally not incident or is minimally incident upon opaque sections of the housing 502. The plurality of LED dies 520 may include LEDs necessary to emit the various lighting configurations as described hereinabove. More specifically, the plurality of LED dies 520 may be operated by the driver circuit 510 so as to emit light according to the various configurations of light as described hereinabove. Accordingly, all the various types, combinations, and ratios of LEDs as described hereinabove may be implements in the present embodiment of the invention. Furthermore, where the housing 502 comprises either of a color conversion layer or a color filter, the plurality of LED dies 520 may be operated so as to emit light that results in the lighting device 500 emitting light according to the various configurations of light as described hereinabove.
Additionally, in some embodiments, the lighting device 500 may include a wireless communication device (not shown) as described hereinabove. The driver circuit 510 may be positioned in electrical communication with the wireless communication device and may operate the plurality of LED dies 520 responsive to signals received from the wireless communication device.
Furthermore, in some embodiments, the driver circuit 510 may be configured to operate the plurality of LED dies 520 responsive to a TRIAC signal as described hereinabove.
Additionally, in some embodiments, the lighting device 500 may be configured not as a bulb to be installed in a lighting fixture, but as the lighting fixture itself. Accordingly, as described hereinabove, the lighting device 500 may be configured to conform to a troffer fixture as is known in the art. More information regarding the configuration of a troffer fixture including LED dies 520 may be found in U.S. patent application Ser. No. 13/842,998 titled Low Profile Light Having Elongated Reflector and Associate Methods filed Mar. 13, 2013, U.S. Pat. No. 8,360,607 entitled Lighting Unit with Heat-Dissipating Chimney filed Feb. 16, 2011, U.S. patent application Ser. No. 13/029,000 entitled Lighting Unit Having Lighting Strips with Light Emitting Elements and a Remote Luminescent Material filed Feb. 16, 2011, and U.S. patent application Ser. No. 13/272,008 entitled Lighting Unit with Light Emitting Elements filed Oct. 12, 2011, the contents of which are incorporated in their entirety herein by reference.
It will be evident to those skilled in the art, that other die configuration or current schemes may be employed to achieve the desired spectral output of the LED lamp for producing biologically adjusted light.
Some of the illustrative aspects of the present invention may be advantageous in solving the problems herein described and other problems not discussed which are discoverable by a skilled artisan.
While the above description contains much specificity, these should not be construed as limitations on the scope of any embodiment, but as exemplifications of the presented embodiments thereof. Many other ramifications and variations are possible within the teachings of the various embodiments. While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best or only mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
Thus the scope of the invention should be determined by the appended claims and their legal equivalents, and not by the examples given.

## Claims

1. A tunable light-emitting diode (LED) lamp for producing biologically-adjusted light, comprising:
a housing comprising a first cap positioned at a first end of the housing and a second cap positioned at a second end of the housing, each of the first and second ends comprising an electrical contact;
a power circuit disposed within the housing having electrical leads attached to at least one of the first and second caps;
a driver circuit disposed within the housing and electrically coupled with the power circuit; and
a plurality of LED dies electrically coupled to and driven by the driver circuit;
wherein the driver circuit is adapted to drive the plurality of LED dies to emit a general illuminating light having a first spectral power distribution and a pre-sleep light having a second spectral power distribution;
wherein the pre-sleep light is characterized by a blue output intensity level, in a visible spectral output range of between 380 nm and 485 nm, that is less than 10% of a relative spectral power of any other peaks in the visible spectral output above 485 nm; and
wherein at least one of the first or second caps is adapted to couple with a tombstone associated with a troffer fixture thereby positioning the first or second cap in electrical communication with the tombstone.

2. The tunable LED lamp of claim 1 wherein the driver circuit is adapted to receive an electrical signal from at least one of the first and second caps; and wherein the driver circuit is adapted to operate the plurality of LED dies responsive to a received electrical signal.

3. The tunable LED lamp of claim 2 further comprising a user input device; wherein the user input device is positioned in electrical communication with at least one of the first and second caps.

4. The tunable LED lamp of claim 3 wherein the user input device is adapted to be a wall-mounted switch.

5. The tunable LED lamp of claim 2 wherein the received electrical signal is a signal received from a TRIAC device.

6. The tunable LED lamp of claim 1 further comprising a wireless communication device positioned in electrical communication with the driver circuit; wherein the wireless communication device is adapted to receive an input from a computerized device; and wherein the driver circuit is adapted to operate the plurality of LED dies responsive to the input received by the wireless communication device.

7. The tunable LED lamp of claim 6 wherein the wireless communication device is adapted to receive a wireless signal via a wireless communication method including at least one of Wi-Fi, Bluetooth, Zigbee, infrared (IR) data transmission, radio, visible light communication (VLC), cellular data service, and Near Field Communication (NFC).

8. The tunable LED lamp of claim 1 wherein:
the driver circuit is further adapted to drive the plurality of LED dies to emit a phase-shift light having a third spectral power distribution; and
the phase-shift light is characterized by a blue output intensity level, in a visible spectral output range of between 455 nm and 485 nm, that is greater than 125% of a relative spectral power of any other peaks in the visible spectral output above 485 nm.

9. The tunable LED lamp of claim 1 wherein:
the driver circuit is further adapted to drive the plurality of LED dies to emit a phase-shift light having a third spectral power distribution; and
the phase-shift light is characterized by a blue output intensity level, in a visible spectral output range of between 455 nm and 485 nm, that is within a range from 150% to 250% of a relative spectral power of any other peaks in the visible spectral output above 485 nm.

10. The tunable LED lamp of claim 1 wherein the general illumination light is characterized by a blue output intensity level, a visible spectral output range of between 380 nm and 485 nm, that is within a range from 20% to 100% of a relative spectral power of any other peaks in the visible spectral output above 485 nm.

11. The tunable LED lamp of claim 1 wherein the plurality of LED dies comprises a ratio of two red-orange LED dies to three cyan LED dies to three mint LED dies to three blue LED dies.

12. The tunable LED lamp of claim 1 wherein the plurality of LED dies comprises a ratio of three cyan LED dies to three mint LED dies to two red-orange LED dies to one blue LED die.

13. A tunable light-emitting diode (LED) lighting device for producing biologically-adjusted light, comprising:
a housing;
a driver circuit;
a plurality of LED dies carried by the housing and electrically coupled to and driven by the driver circuit; and
a communication device positioned in electrical communication with the driver circuit;
wherein the driver circuit is adapted to drive the plurality of LED dies to emit a phase-shift light having a first spectral power distribution and a general illuminating light having a second spectral power distribution;
wherein the phase-shift light is characterized by a blue output intensity level, in a visible spectral output range of between 455 nm and 485 nm, that is greater than 125% of a relative spectral power of any other peaks in the visible spectral output above 485 nm;
wherein the communication device is adapted to receive an input; and
wherein the driver circuit is adapted to operate the plurality of LED dies responsive to the input received by the communication device.

14. The tunable LED lighting device of claim 13 wherein:
the driver circuit is further adapted to drive the plurality of LED dies to emit a pre-sleep light having a third spectral power distribution; and
the pre-sleep light is characterized by a blue output intensity level, in a visible spectral output range of between 380 nm and 485 nm, that is less than 10% of a relative spectral power of any other peaks in the visible spectral output above 485 nm.

15. The tunable LED lighting device of claim 13 wherein the phase-shift light is characterized by a blue output intensity level, in a visible spectral output range of between 455 nm and 485 nm, that is within a range from 150% to 250% of a relative spectral power of any other peaks in the visible spectral output above 485 nm.

16. The tunable LED lighting device of claim 13 wherein the general illumination light is characterized by a blue output intensity level, in a visible spectral output range of between 380 nm and 485 nm, that is within the range from 20% to 100% of a relative spectral power of any other peaks in the visible spectral output above 485 nm.

17. The tunable LED lighting device of claim 13 wherein the housing is configured as a troffer fixture.

18. A tunable light-emitting diode (LED) lighting device for producing biologically-adjusted light, comprising:
a troffer housing;
a driver circuit; and
a plurality of LED dies carried by the troffer housing and electrically coupled to and driven by the driver circuit;
wherein the driver circuit is adapted to drive the plurality of LED dies to emit a phase-shift light having a first spectral power distribution and a general illuminating light having a second spectral power distribution; and
wherein the phase-shift light is characterized by a blue output intensity level, in a visible spectral output range of between 455 nm and 485 nm, that is within a range from 150% to 250% of a relative spectral power of any other peaks in the visible spectral output above 485 nm.

19. The tunable LED lighting device of claim 18 wherein:
the driver circuit is further adapted to drive the plurality of LED dies to emit a pre-sleep light having a third spectral power distribution; and
the pre-sleep is characterized by a blue output intensity level, in a visible spectral output range of between 380 nm and 485 nm, that is less than 10% of a relative spectral power of any other peaks in the visible spectral output above 485 nm.

20. The tunable LED lighting device of claim 18 wherein the general illumination light is characterized by a blue output intensity level, in a visible spectral output range of between 380 nm and 485 nm, that is within the range from 20% to 100% of a relative spectral power of any other peaks in the visible spectral output above 485 nm.