US20090189549A1

US20090189549A1 - Heat Dissipation in a Lighting System and Method Thereof

Info

Publication number: US20090189549A1
Application number: US12/197,589
Authority: US
Inventors: John D. Crawford; Guy R. Wagner
Original assignee: Eveready Battery Co Inc
Current assignee: Edgewell Personal Care Brands LLC
Priority date: 2008-01-25
Filing date: 2008-08-25
Publication date: 2009-07-30
Also published as: EP2236010A1; AU2009206773A1; US20090189566A1; US20100259220A1; WO2009094121A1; EP2236010A4; WO2009094118A2; US7888883B2; WO2009094118A3; US20090189541A1; US20110115397A1; WO2009094381A1; US8324836B2; US8063607B2

Abstract

A lighting system is provided that includes at least one lighting device, at least one connector, and a plurality of external power sources. The at least one lighting device includes at least one lighting source, and an internal power source applying a first electrical current to illuminate the at least one lighting element, wherein the internal power source supplies the first electrical current. The at least one connector electrically connects to the at least one lighting device. The plurality of external power sources include at least first and second external power sources that are adapted to be electrically connected to the at least one lighting device by the at least one connector. The first external power source supplies a second electrical current to the at least one lighting device to illuminate the at least one lighting source and the second external power source supplies a third electrical current to illuminate the at least one lighting source, such that the internal power source and one of the plurality of external power sources each supply electrical current to illuminate the at least one lighting source at different times.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/023,632, filed on Jan. 25, 2008, the entire disclosure of which is hereby incorporated herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to a lighting system and method thereof, and more particularly, to heat dissipation in a lighting system and method thereof.

BACKGROUND OF THE INVENTION

Generally, a mobile lighting device, such as a flashlight, is powered by a power source that is internal to the flashlight, such as a battery. Typically, the batteries of the flashlight device can be replaced when the state of charge of the batteries is below an adequate state of charge for providing electrical power for the light source of the flashlight. Since the flashlight is being powered by batteries, the flashlight can generally emit light while not being electrically connected to a power source that is external to the flashlight, such as an alternating current (AC) wall outlet.
Additionally, when the batteries of the flashlight have a state of charge that is below an adequate state of charge level, the batteries can be replaced with other batteries. If the removed batteries are rechargeable batteries, then the removed batteries can be recharged using an external recharging device, and re-inserted into the flashlight. When the removed batteries are not rechargeable batteries, then the non-rechargeable batteries are replaced with new batteries.
Alternatively, a flashlight may contain an electrical connector in order to connect to a specific type of power source, such as the AC wall outlet, in addition to the batteries. Typically, when the flashlight is connected to the stationary external power supply, the flashlight can continue to illuminate light, but the mobility of the flashlight is now hindered. If the flashlight is directly connected to the AC wall outlet, then the mobility of the flashlight is generally eliminated. When the flashlight is not directly connected to the AC wall outlet, such as by an extension cord, the flashlight has limited mobility.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, a lighting device is provided that includes at least one lighting source, at least one circuit board, a housing, a thermistor, and a controller. The at least one lighting source is electrically connected to the at least one circuit board. The housing encloses the at least one lighting source and the at least one circuit board, wherein the housing is in thermal communication with the at least one lighting source to dissipate heat generated by the plurality of lighting sources. The thermistor is in thermal communication with the at least one circuit board and the housing to monitor a temperature thereof. The controller is in communication with the thermistor, wherein the controller performs the steps of determining a temperature of the other of the at least one circuit board and the housing not in thermal communication with the thermistor based upon the monitored temperature, and altering an electrical power supplied to the at least one lighting source based upon the monitored temperature and the determined temperature to maintain at least one of the monitored temperature and the determined temperature below a temperature value associated with the at least one circuit board and the housing, respectively.
In accordance with another aspect of the present invention, a lighting device is provided that includes a plurality of lighting sources, at least one circuit board electrically connected to the plurality of lighting sources, a housing, a single thermistor, and a controller. The housing encloses the plurality of lighting sources and the at least one circuit board, wherein the housing is in thermal communication with the plurality of lighting sources to dissipate heat generated by the plurality of lighting sources. The single thermistor is in thermal communication with one of the at least one circuit board and the housing to monitor a temperature thereof. The controller is in communication with the thermistor, wherein the controller performs the steps of determining a temperature of one of the at least one circuit board and the housing not in thermal communication with the thermistor based upon the monitored temperature determined by the single thermistor, and altering an electrical current supplied to at least a portion of the plurality of lighting sources based upon the monitored temperature and the determined temperature to maintain at least one of the monitored temperature and the determined temperature below a temperature value associated with the at least one circuit board and the housing, respectively.
In accordance with yet another aspect of the present invention, a method of controlling thermal radiation emitted by a lighting device is provided that includes the steps of supplying an electrical power to at least one lighting source, emitting thermal radiation by the at least one lighting source when receiving the electrical power, and monitoring directly a temperature of the emitted thermal radiation of the at least one lighting source. The method further includes the steps of determining a temperature of a second component based upon the monitored temperature, and decreasing the electrical power supplied to the at least one lighting source when at least one of the monitored temperature and the determined temperature are above a value associated therewith, respectively.
These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of a lighting system having a plurality of lighting devices and a plurality of external power sources, in accordance with one embodiment of the present invention;

FIG. 2A is a circuit diagram of a handheld lighting device of a lighting system, in accordance with one embodiment of the present invention;

FIG. 2B is a circuit diagram of the handheld lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 3A is a circuit diagram of a headlight lighting device of a lighting system, in accordance with one embodiment of the present invention;

FIG. 3B is a circuit diagram of the headlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 4A is a circuit diagram of a spotlight lighting device of a lighting system, in accordance with one embodiment of the present invention;

FIG. 4B is a circuit diagram of the spotlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 5A is a circuit diagram of an energy storage system of a lighting system, in accordance with one embodiment of the present invention;

FIG. 5B is a circuit diagram of the energy storage system of the lighting system, in accordance with one embodiment of the present invention;

FIG. 6 is a flow chart illustrating a method of an electrical current supported by an external power source bypassing an internal power source of a lighting device of a lighting system, in accordance with one embodiment of the present invention;

FIG. 7A′ is a front perspective view of a handheld lighting device of a lighting system illustrating vertical heat sink fins, in accordance with an alternate embodiment of the present invention;

FIG. 7A is front perspective view of a handheld lighting device of a lighting system, in accordance with one embodiment of the present invention;

FIG. 7B is an exploded view of the handheld lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 7C is a cross-sectional view of the handheld lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 7D is an exploded view of a handheld lighting device of a lighting system, in accordance with an alternate embodiment of the present invention;

FIG. 8A is a front perspective view of a headlight lighting device of a lighting system, in accordance with one embodiment of the present invention;

FIG. 8B is an exploded view of the headlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 8C is a cross-sectional view of the headlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 8D is an exploded view of an internal power source of the headlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 9A is a side perspective view of a spotlight lighting device of a lighting system, in accordance with one embodiment of the present invention;

FIG. 9B is an exploded view of the spotlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 9C is a cross-sectional view of the spotlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 10A is a top perspective view of a solar power source of a lighting system in a solar radiation harvesting position, in accordance with one embodiment of the present invention;

FIG. 10B is an exploded view of the solar power source of the lighting system in a solar radiation harvesting position, in accordance with one embodiment of the present invention;

FIG. 10C is a front perspective view of the solar power source of the lighting system in a rolled-up position, in accordance with one embodiment of the present invention;

FIG. 11A is a front perspective view of an electrical connector of a lighting system, in accordance with one embodiment of the present invention;

FIG. 11B is an exploded view of the electrical connector of the lighting system, in accordance with one embodiment of the present invention;

FIG. 11C is a cross-sectional view of the electrical connector of the lighting system, in accordance with one embodiment of the present invention;

FIG. 12A is a front perspective view of an optic pack of a handheld lighting device of a lighting system, in accordance with one embodiment of the present invention;

FIG. 12B is a top plan view of the optic pack of the handheld lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 12C is a side plan view of the optic pack of the handheld lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 13A is a top perspective view of an optic pack of a headlight lighting device of a lighting system, in accordance with one embodiment of the present invention;

FIG. 13B is a top plan view of the optic pack of the headlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 13C is a side plan view of the optic pack of the headlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 14A is a side perspective view of an optic pack of a spotlight lighting device of a lighting system, in accordance with one embodiment of the present invention;

FIG. 14B is a top plan view of the optic pack of the spotlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 14C is a front plan view of the optic pack of the spotlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 14D is a side plan view of the optic pack of the spotlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 15A is a top perspective view of a lens of the optic pack of the spotlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 15B is a top plan view of the lens of the optic pack of the spotlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 15C is a front plan view of the lens of the optic pack of the spotlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 15D is a side plan view of the lens of the optic pack of the spotlight lighting device of the lighting system, in accordance with one embodiment of the present invention;

FIG. 16A is a flow chart illustrating a method of controlling at least one component of a lighting device of a lighting system based upon a temperature of at least one component in the lighting device, in accordance with one embodiment of the present invention;

FIG. 16B is a flow chart illustrating a method of controlling at least one component of a lighting device of a lighting system based upon a rate of temperature change of at least one component in the lighting device, in accordance with an alternate embodiment of the present invention; and

FIG. 17 is an exemplary illustration of an illumination pattern emitted by a lighting source of a lighting device in a lighting system, in accordance with one embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments include combinations of method steps and apparatus components related to a lighting system and method of operating thereof. Accordingly, the apparatus components and method steps have been represented, where appropriate, by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Further, like reference characters in the description and drawings represent like elements.
In this document, relational terms, such as first and second, top and bottom, and the like, may be used to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

I. Lighting System

In reference to FIGS. 1-11, a lighting system is generally shown at reference identifier 10. The lighting system 10 includes at least one lighting device 14, at least one electrical connector generally indicated at 12, and one or more power sources 16,20,22,24,26,27. According to one embodiment, the at least one lighting device includes a handheld lighting device generally indicated at 14A, a headlight lighting device generally indicated at 14B, and a spotlight lighting device generally indicated at 14C. For purposes of explanation and not limitation, the invention is generally described herein with regards to the at least one lighting device including the handheld lighting device 14A, the headlight lighting device 14B, and the spotlight lighting device 14C; however, it should be appreciated by those skilled in the art that the lighting system 10 can include a combination of the lighting devices 14A,14B,14C and/or additional lighting devices. The at least one lighting device typically includes at least one lighting source and an internal power source, generally indicated at 16, that supplies a first electrical current to illuminate the at least one lighting source, as described in greater detail herein. However, it should be appreciated by those skilled in the art that other embodiments include devices that emit the at least one lighting device 14A,14B,14C and/or the internal power source 16. According to one embodiment, the lighting system 10 can include non-lighting devices, such as, but not limited to, a weather radio, a global positioning satellite (GPS) system receiver, an audio player, a cellular phone, the like, or a combination thereof.
According to one embodiment, the at least one lighting source includes a white flood light emitting diode (LED) 18A, a white spot LED 18B, and a red flood LED 18C. Typically, the white flood LED 18A and white spot LED 18B emit a white light having two different illumination patterns, wherein the white flood LED 18A illumination pattern disperses the emitted light over a greater area than the white spot LED 18B, as described in greater detail below. It should be appreciated by those skilled in the art that the white flood LED 18A, white spot LED 18B, and red flood LED 18C can be any desirable color, such as, but not limited to, white, red, blue, suitable colors of light in the visible light wavelength spectrum, infrared, suitable colors of light in the non-visible light wavelength spectrum, the like, or a combination thereof.
According to one embodiment, the flood beam pattern illuminates a generally conical shaped beam having a circular cross-section with a target size in diameter of approximately two meters (2 m) or greater at a target distance of approximately one hundred meters (100 m), and the spot beam pattern illuminates a generally conical shaped beam having a circular cross-section with a target size in diameter of approximately less than one meter (1 m) at a target distance of two meters (2 m). Thus, the flood beam pattern can be defined as the light being emitted at a half angle of twelve degrees (12°) or greater with respect to the lighting source 18A, and the spot beam pattern can be defined as the light being emitted at a half angle of less than twelve degrees (12°) with respect to the lighting source 18B. According to one embodiment, the spot lighting source 18B can have a half angle of less than or equal to approximately five degrees (5°) for the handheld and headlight lighting devices 14A,14B, and a half angle of less than or equal to approximately two degrees (2°) for the spotlight lighting device 14C. The red flood LED 18C can have a similar illumination pattern to the white flood LED 18A while emitting a red-colored light. According to one embodiment, the term illumination pattern generally refers to the size and shape of the illuminated area at a target distance, angles of the emitted light, the intensity of the emitted light across the beam, the illuminance of the beam (e.g., the total luminous flux incident on a surface, per unit area), or a combination thereof. The shape of the illumination pattern can be defined as the target area containing approximately eighty percent to eighty-five percent (80%-85%) of the emitted light.
It should be appreciated by those skilled in the art that the flood and/or the spot illumination patterns can form or define shapes other than circles, such as, but not limited to, ovals, squares, rectangles, triangles, symmetric shapes, non-symmetric shapes, the like, or a combination thereof. It should further be appreciated by those skilled in the art that the lighting sources 18A,18B,18C can be other combinations of lighting sources with different illumination patterns, such as, but not limited to, two or more flood lighting sources, two or more spot lighting sources, or a combination thereof.
For purposes of explanation and not limitation, the invention is generally described herein with regards to the at least one lighting source including the white flood LED 18A, the white spot LED 18B, and the red flood LED 18C. However, it should be appreciated by those skilled in the art that the lighting system 10 can include lighting devices 14A,14B,14C having a combination of lighting sources 18A,18B,18C and/or additional lighting sources. According to one embodiment, the light sources 18A,18B,18C are connected to a LED circuit board 19, as described in greater detail below.
The plurality of power sources include a plurality of external power sources, wherein the plurality of external power sources include at least first and second external power sources that are adapted to be electrically connected to the at least one lighting device by the at least one electrical connector 12. Typically, the electrical connector 12 electrically connects the external power source to the lighting device 14A,14B,14C. By way of explanation and not limitation, the plurality of external power sources can include an alternating current (AC), such as a 120 Volt wall outlet, power source 20, a direct current (DC) power source 22, such as an outlet in a vehicle, an energy storage system generally indicated at 24, a solar power source 26, a solar power energy storage system 27, the like, or a combination thereof. It should be appreciated by those skilled in the art that other types of external power sources can be configured to connect with the lighting device 14A,14B,14C.
For purposes of explanation and not limitation, the handheld lighting device 14A can be adapted to be held by a single hand of a user, wherein the hand of the user wraps around the longitudinally extending handheld lighting device 14A. Thus, a thumb of the user's hand is positioned to actuate at least one switch SW1,SW2,SW3, or SW4, which alters the light emitted by the handheld lighting device 14A, as described in greater detail herein. The headlight lighting device 14B can be adapted to be placed over a user's head using a headband 21, wherein the user actuates the at least one switch SW1,SW2,SW3, or SW4 using one or more fingers of the user's hand in order to alter the light emitted from the headlight lighting device 14B, as described in greater detail herein. Thus, a user generally directs the light emitted by the headlight lighting device 14B by moving their head. Additionally or alternatively, the spotlight lighting device 14C is adapted to be held in the hand of a user, wherein the user's hand wraps around a handle portion 17 of the spotlight lighting device 14C. Typically, a user's hand is positioned on the handle portion 17, such that an index finger of the user's hand can actuate switches SW1,SW2, or SW3, and a middle finger of the user's hand can be used to actuate switch SW4, which alters the light emitted by the spotlight lighting device 14C, as described in greater detail herein. Generally, the spotlight lighting device 14C illuminates objects with the light emitted from the lighting source 18B at a greater distance than objects illuminated by light emitted from the handheld lighting device 14A and headlight lighting device 14B.
Typically, the lighting devices 14A,14B,14C include the internal power source 16, and are electrically connected to the external power sources 20,22,24,26, or 27 by the electrical connector 12. The lighting devices 14A,14B,14C can be electrically connected to the external power sources 20,22,24,26, or 27 at the discretion of the user of the lighting system 10, such that the lighting devices 14A,14B,14C are not consuming electrical power from the internal power source 16 when the lighting devices 14A,14B,14C are electrically connected to one of the external power sources 20,22,24,26, or 27. Thus, if a user does not desire to consume the electrical power of the internal power source 16 or the state of charge of the internal power source 16 is below an adequate level, the user can electrically connect one of the external power sources 20,22,24,26, or 27 to the lighting device 14A,14B,14C, such that the electrically connected power source 20,22,24,26, or 27 supplies an electrical current to the lighting source 18A,18B,18C, according to one embodiment. Further, one or more of the external power sources can be a rechargeable power source that can be charged by other external power sources of the lighting system 10, or other power sources external to the lighting system 10.
According to one embodiment, the first external power source supplies a second electrical current to the at least one lighting device to illuminate the at least one lighting source 18,18B,18C, and the second external power source supplies a third electrical current to illuminate the at least one lighting source 18A,18B,18C, such that the internal power source 16 and one of the plurality of external power sources each supply electrical current to illuminate the at least one lighting source 18A,18B,18C at different times, as described in greater detail herein. The first, second, and third electrical currents are supplied at at least two different voltage potentials. According to one embodiment, the AC power source 20 receives electrical current from an AC source at a voltage potential ranging from substantially ninety Volts (90 VAC) to two hundred forty Volts (240 VAC) at fifty hertz (50 Hz) or sixty hertz (60 Hz), and supplies an electrical current to the lighting devices 14A,14B,14C at a voltage potential of about substantially 12 Volts, the DC power source 22 supplies the electrical current at a voltage potential of about substantially 12 Volts, the energy storage system 24 and solar power energy storage system 27 supply the electrical current at a voltage potential of about substantially 3.6 Volts, and the solar power source 26 supplies the electrical current at a voltage potential of substantially 8 Volts. According to one embodiment, the internal power source 16 can be an electrochemical cell battery configured as a 1.5 Volt power source, such as, but not limited to, an alkaline battery, a nickel metal hydride (NiMH) battery, or the like. Alternatively, the internal power source 16 can be an electrochemical cell battery configured as a 3.6 Volt-3.7 Volt power source, such as a lithium ion (Li-Ion) battery, or the like. Thus, the lighting devices 14A,14B,14C can be supplied with an electrical current having a voltage potential ranging from and including approximately 1.5 Volts to 12 Volts in order to illuminate the lighting sources 18A,18B,18C.
According to one embodiment, the lighting devices 14A,14B,14C can each include a first electrical path generally indicated at 28, and a second electrical path generally indicated at 30, wherein both the first electrical path 28 and second electrical path 30 are internal to the lighting device 14A,14B,14C (FIGS. 2B, 3B, and 4B). Typically, the internal power source 16 provides the electrical current to the lighting source 18A,18B,18C through the first electrical path 28, and the plurality of external power sources 20,22,24,26,27 supply the electrical current via the electrical connector 12 to the lighting source 18A,18B,18C through the second electrical path 30, such that the second electrical path 30 bypasses the first electrical path 28. According to an alternate embodiment, the external power sources 20,22,24,26,27, when connected to the lighting device 14A,14B,14C, supply the electrical current via the electrical connector 12 through the second electrical path 30 to illuminate the lighting element 18A,18B,18C and supply an electrical current to the internal power source 16 to recharge the internal power source. It should be appreciated by those skilled in the art that in such an embodiment, the internal power source 16 is a rechargeable power source (FIG. 1). According to another embodiment, the lighting device 14A,14B,14C is not configured to be electrically connected to the external power sources 20,22,24,26,27, and thus, is not adapted to be connected to the connector 12.
The lighting devices 14A,14B,14C typically include the internal power source 16 and are configured to connect to one of the external power sources 20,22,24,26, or 27 at a time. A battery voltage monitor generally indicated at 34 is in electrical communication with the internal power source 16 and the external power sources 20,22,24,26,27, when one of the external power sources 20,22,24,26, or 27 is connected. The battery voltage monitor 34 determines if the internal power source 16 and external power source 20,22,24,26,27 have a voltage potential. According to one embodiment, a processor or microprocessor 36 powers or turns on transistors Q10 of the battery voltage monitor 34, so that the lighting device 14A,14B, or 14C can determine if the internal power source 16 or the connected external power source 20,22,24,26, or 27 has a voltage potential. Thus, the battery voltage monitor 34 activates a switch to turn on one of an internal battery selector, generally indicated at 38, or an external battery selector, generally indicated at 40. According to one embodiment, the internal battery selector 38 is turned on by switching transistors Q8, which can be back-to-back field-effect transistors (FETs), and the external battery selector 40 is turned on by switching transistors Q9, which can be back-to-back FETs.
In regards to FIGS. 1-6, a method of supplying electrical current from the power sources 16,20,22,24,26,27 is generally shown in FIG. 6 at reference identifier 1000. The method 1000 starts at step 1002, and proceeds to step 1004, wherein the at least one switch SW1 or SW4 is actuated, according to one embodiment. At step 1006, the voltage potential of at least one of the power sources 16,20,22,24,26,27 are determined. At decision step 1008, it is determined if an external power source 20,22,24,26,27 is connected to the lighting device 14A,14B,14C. According to one embodiment, the external power sources 20,22,24,26,27 have a greater voltage potential than the internal power source 16 when the external power source 20,22,24,26,27 is charged (e.g., energy storage system 24), and thus, by determining the voltage potential of the power sources 16,20,22,24,26,27 at step 1006, when there are multiple determined voltage potentials, then the higher voltage potential is assumed to be the external power source 20,22,24,26,27.
If it is determined at decision step 1008 that there is not an external power source 20,22,24,26, or 27 connected to the lighting device 14A,14B,14C, then the method 1000 proceeds to step 1010, wherein the internal battery selector 38 is turned on. At step 1012, electrical current is supplied from the internal power source 16 to a lighting source 18A,18B,18C through the first electrical path 28, and the method 1000 then ends at step 1014. However, if it is determined at decision step 1008 that one of the external power sources 20,22,24,26, or 27 is connected to the lighting device 14A,14B,14C, then the method 1000 proceeds to step 1016, wherein the external battery selector 40 is turned on. At step 1018, electrical current is supplied from the external power source 20,22,24,26, or 27 to the lighting source 18A,18B,18C through the second electrical path 30, and the method 1000 then ends at step 1014. It should be appreciated by those skilled in the art that if the external power source 20,22,24,26, or 27 is connected to the lighting device 14A,14B,14C, after the switch SW1 or SW4 has been actuated to turn on the lighting source 18A,18B,18C, then the method 1000 starts at step 1002, and proceeds directly to step 1006, wherein the voltage potential of the power sources 16,20,22,24,26,27 is determined.
With regards to FIGS. 1-5 and 7-11, the lighting devices 14A,14B,14C can include a voltage regulator 42 (FIGS. 2B, 3B, and 4B). According to one embodiment, the voltage regulator 42 is a 3.3 voltage regulator, wherein the voltage regulator 42 receives an electrical current from the internal power source 16, the external power source 20,22,24,26, or 27, or a combination thereof. Typically, the voltage regulator 42 determines which of the internal power source 16 and the external power source 20,22,24,26,27 have a higher voltage potential, and uses that power source 16,20,22,24,26, or 27 to power the processor 36. However, it should be appreciated by those skilled in the art that the voltage regulator 42 can include hardware circuitry, execute one or more software routines, or a combination thereof to default to the internal power source 16 or the external power source 20,22,24,26,27, when present, to power the processor 36. Thus, the voltage regulator 42 regulates the voltage of the selected power source 16,20,22,24,26,27 to supply electrical power at a regulated voltage potential to the processor 36.
Additionally or alternatively, the lighting devices 14A,14B,14C can include a converter 44, a voltage limiter 46, at least one LED driver, a reference voltage device 48, at least one fuel gauge driver, a temperature monitor device generally indicated at 50, or a combination thereof, as described in greater detail herein. The processor 36 can communicate with a memory device to execute one or more software routines, based upon inputs received from the switches SW1,SW2,SW3,SW4, the temperature monitor device 50, the like, or a combination thereof. According to one embodiment, the converter 44 is a buck-boost converter that has an output DC voltage potential from the input DC voltage potential, and the voltage limiter 46 limits the voltage potential of the electrical current supplied to the lighting sources 18A,18B,18C to suitable voltage potentials. The plurality of LED drivers can include, but are not limited to, a flood LED driver 52A, a spot LED driver 52B, and a red LED driver 52C that corresponds to the respective lighting source 18A,18B,18C. According to one embodiment, the reference voltage device 48 supplies a reference voltage potential of 2.5 Volts to the processor 36 and temperature monitor device 50.
According to one embodiment, the lighting devices 14A,14B,14C, the AC power source 20, the DC power source 22, or a combination thereof include components that are enclosed in a housing generally indicated at 54. Additionally or alternatively, the energy storage system 24, the solar power source 26, the solar energy storage system 27, or a combination thereof can include components that are enclosed in the housing 54. According to one embodiment, the housing 54 is a two-part housing, such that the housing 54 includes corresponding interlocking teeth 56 that extend along at least a portion of the connecting sides of the housing 54. According to one embodiment, the interlocking teeth 56 on a first part of the two-part housing interlock with corresponding interlocking teeth 56 of a second part of the two-part housing in order to align the corresponding parts of the housing 54 during assembly of the device. The interlocking teeth 56 can also be used to secure the parts of the housing 54. However, it should be appreciated by those skilled in the art that additional connection devices, such as mechanical connection devices (e.g., threaded fasteners) or adhesives, can be used to connect the parts of the housing 54. Further, the interlocking teeth 56 can be shaped, such that a force applied to a portion of the housing 54 is distributed to other portions of the two-part housing 54 along the connection point of the interlocking teeth 56.
In accordance with an alternate embodiment shown in FIG. 7D, the housing 54 of the handheld lighting device 14A can be a tubular housing, wherein the internal power source 16 and the circuit board 39 are contained in a longitudinally extending bore of the tubular housing 54. An end cap, generally indicated at 59, can enclose a first end or a front end of the tubular housing 54. According to one embodiment, the end cap 59 includes an optic pack 57, which includes at least the lighting sources 18A,18B,18C, wherein the optic pack 57A is described in greater detail below. Thus, the end cap 59 can be a light emitting end of the handheld lighting device 14A. Additionally, a tail cap assembly, generally indicated at 88, can be used to enclose a second end of the tubular housing 54. The tail cap assembly 88 includes a connector 92, as described in greater detail below. According to one embodiment, the tubular housing 54 can include external features, such as thermally conductive heat sink fins 74. According to an alternate embodiment, an external component 61 can be attached to the tubular housing 54, wherein the external component 61 includes external features, such as the thermally conductive heat sink fins 74. The external component 61 can be attached to the tubular housing 54 by any suitable form of attachment, such as, but not limited to, a mechanical attachment device, an adhesive, the like, or a combination thereof.
According to one embodiment, the handheld lighting device 14A has the internal power source 16, which includes three (3) AA size batteries connected in series. Typically, at least two of the AA batteries are positioned side-by-side, such that the three (3) AA size batteries are not each end-to-end, and a circuit board 39 is positioned around the three (3) AA size batteries within the housing 54. According to one embodiment, the internal power source 16 of the headlight lighting device 14B is not housed within the same housing as the light sources 18A,18B,18C, but can be directly electrically connected to the lighting sources 18A,18B,18C and mounted on the headband 21 as the housing 54 enclosing the lighting sources 18A,18B,18C. Thus, the internal power source 16 of the headlight lighting device 14B differs from the external power sources 20,22,24,26,27 that connect to the headlight lighting device 14B with the electrical connector 12. Further, the headlight lighting device 14B can include one or more internal power sources 16 that have batteries enclosed therein. Typically, the internal power source 16 of the headlight lighting device 14B includes three (3) AAA size batteries, as shown in FIG. 8D. Typically, AAA size batteries are used in the headlight lighting device 14B in order to reduce the weight of the headlight lighting device 14B, which is generally supported by the user's head, when compared to the weight of other size batteries (e.g., AA size batteries, C size batteries, etc.). According to one embodiment, the spotlight lighting device 14C has the internal power source 16, which includes six (6) AA size batteries, each supplying about 1.5 Volts, and electrically coupled in series to provide a total voltage potential of about nine Volts (9 V). Typically, the six (6) AA size batteries are placed in a clip device 23 and inserted into the handle 17 of the housing 54 of the spotlight lighting device 14C, as shown in FIG. 9B. However, it should be appreciated by those skilled in the art that batteries of other shapes, sizes, and voltage potentials can be used as the internal power source 16 of the lighting devices 14A,14B,14C.
In regards to FIGS. 1 and 10A-10C, the solar power source 26 includes a film material 29 having panels, wherein the panels receive radiant solar energy from a solar source, such as the sun. According to one embodiment, the film material 29 includes one (1) to five (5) panels. The film material 29, via the panels, receives or harvests the solar energy, such that the solar energy is converted into an electrical current, and the electrical current is propagated to the lighting device 14A,14B,14C or the energy storage system 24,27 through the electrical connector 12. According to one embodiment, the solar radiation received by the solar power source 26 is converted into an electrical current having a voltage potential of approximately eight volts (8V). Further, film material 29 can be a KONARKA™ film material, such as a composite photovoltaic material, in which polymers with nano particles can be mixed together to make a single multi-spectrum layer (fourth generation), according to one embodiment. According to other embodiments, the film material 29 can be a single crystal (first generation) material, an amorphous silicon, a polycrystalline silicon, a microcrystalline, a photoelectrochemical cell, a polymer solar cell, a nanocrystal cell, and a dyesensitized solar cell. Additionally, the solar power source 26 can include protective cover films 31 that cover a top and bottom of the film material 29. For purposes of explanation and not limitation, the protective cover film 31 can be any suitable protective cover film, such as a laminate, that allows solar radiation to substantially pass through the protective cover film 31 and be received by the film material 29.
According to one embodiment, the film material 29 and the protective cover film 31 are flexible materials that can be rolled or wound about a mandrel 33. The mandrel 33 can have a hollow center, such that the electrical connector 12 or other components can be stored in the mandrel 33. Straps 35 can be used to secure the film material 29 and the protective cover film 31 to the mandrel when the film material 29 and protective cover film 31 are rolled about the mandrel 33 or in a rolled-up position, according to one embodiment. Additionally, the straps 35 can be used to attach the solar power source 26 to an item, such as, but not limited to, a backpack or the like, when the film material 29 and protective cover film are not rolled about the mandrel 33 or in a solar radiation harvesting position. Additionally or alternatively, end caps 37 can be used to further secure the film material 29 and protective cover film 31 when rolled about the mandrel 33, and to provide access to the hollow interior of the mandrel 33.
According to an alternate embodiment, the film material 29 can be a foldable material, such that the film material 29 can be folded upon itself in order to be stored, such as when the solar power source 26 is in a non-solar radiation harvesting position. Further, the film material 29, when in the folded position, can be stored in the mandrel 33, other suitable storage containers, or the like. Additionally, the protective cover film 31 can be a foldable material, such that both the film material 29 and protective cover film 31 can be folded when in a non-solar radiation harvesting position. The film material 29 and protective cover film 31 can then also be un-folded when the film material 29 is in a solar radiation harvesting position.
With respect to FIGS. 1-5 and 7-11, the electrical connector 12 includes a plurality of pins 41 connected to a plurality of electrical wires 43 that extend longitudinally through the electrical connector 12, according to one embodiment. Typically, the plurality of pins 41 are positioned, such that the pins 41 matingly engage to make an electrical connection with a electrical component of the device 14A,14B,14C,20,22,24,26,27 that is connected to the electrical connector 12. Thus, the electrical wires 43, and the pins 41, can communicate or propagate an electrical current between one of the light devices 14A,14B,14C and one of the external power sources 20,22,24,26, or 27 and between the external power sources (i.e. the AC power source 20 to the energy storage system 24) at different voltage potentials. According to one embodiment, the electrical connector 12 communicates an intelligence signal from the power source 20,22,24,26,27 to the lighting device 14A,14B,14C, such that the lighting device 14A,14B,14C can confirm that the electrical connector 12 is connecting a suitable external power source to the connected lighting device 14A,14B,14C.
According to one embodiment, the connector 41 includes an outer sleeve 45 having a first diameter and an inner sleeve 47 having a second diameter, wherein the second diameter is smaller than the first diameter. The connector 41 can further include a retainer 49 that surrounds at least a portion of the plurality of pins 41 and the electrical wires 43, according to one embodiment. The retainer 49, in conjunction with other components of the electrical connector 12, such as the outer sleeve 45 and inner sleeve 47, form a water-tight seal, so that a waterproof connection between the pins 41 and the electrical components of the connected device 14A,14B,14C,20,22,24,26,27.
Additionally or alternatively, the connector 41 includes a quarter-turn sleeve 51, which defines at least one groove 53 that extends at least partially circumferentially, at an angle, around the quarter-turn sleeve 51. According to one embodiment, the electrical connector 12 includes a flexible sleeve 55 at the non-connecting end of the quarter-turn sleeve 51 that connects to a protective sleeve 59. Typically, the protective sleeve 59 extends longitudinally along the length of the electrical connector 12 to protect the wires 43, and the flexible sleeve 55 allows the ends of the electrical connector 12 to be flexible so that the pins 41 can be correctly positioned with respect to a receiving portion of the device 14A,14B,14C,20,22,24,26, or 27.
The spotlight lighting device 14C can also include a switch guard 32, according to one embodiment. Additionally or alternatively, the devices 14A,14B,14C,20,22,24,26,27 can include the tail cap assembly 88. The tail cap assembly 88 includes a hinge mechanism 90, wherein at least one cover is operably connected to the hinge mechanism 90, such that the at least one cover pivots about the hinge mechanism 90. According to one embodiment, a connector 92 is attached or integrated onto a cover 94, wherein the connector 92 is the corresponding male portion to the electrical connector 12. The connector 92 can include a flange that is positioned to slidably engage the groove 53 of the electrical connector 12 when the connector 92 is being connected and disconnected from the electrical connector 12, according to one embodiment. The connector 92 is electrically connected to the lighting sources 18A,18B,18C when the cover 94 is in a fully closed positioned, such that when one of the external power sources 20,22,24,26, or 27 is connected to one of the lighting devices 14A,14B, or 14C by the electrical connector 12 being connected to the connector 92, the external power source 20,22,24,26,27 propagates an electrical current to the lighting sources 18A,18B,18C. When the cover 94 is in an open position, the connector 92 is not electrically connected to the lighting sources 18A,18B,18C, and the internal power source 16 can be inserted and removed from the lighting device 14A,14B,14C.
According to an alternate embodiment, the tail cap assembly 88 includes a second cover 96 that covers the connector 92 when in a fully closed position. Typically, the second cover 96 is operably connected to the hinge mechanism 90, such that the second cover pivots about the hinge mechanism 90 along with the cover 94. When the second cover 96 is in the fully closed position, the electrical connector 12 cannot be connected to the connector 92, and when the second cover 96 is in an open position, the electrical connector 12 can be connected to the connector 92. Thus, the connector 92 does not have to be exposed to the environment that the lighting device 14A,14B,14C is being operated in, when the connector 92 is not connected to the electrical connector 12. Further, the tail cap assembly 88 can include a fastening mechanism 98 for securing the cover 94,96 when the cover 94,96 is in the fully closed position.

II. Optic Pack

In regards to FIGS. 1-5, 7-9, 12-15, and 17, the lighting devices 14A,14B,14C have a plurality of lighting sources enclosed in the housing 54, wherein at least one light source 18A,18B,18C of the plurality of light sources emits lights. According to one embodiment, each of the light sources 18A,18B,18C are in optical communication with a corresponding optic pack generally indicated at 57A,57B,57C. Typically, the optic pack 57A,57B,57C includes an optical lens, such that a plurality of optical lenses are enclosed in the housing 54, wherein each of the plurality of light sources 18A,18B,18C is in optical communication with one optical lens of the plurality of optical lenses. According to one embodiment, the plurality of optical lenses include a first optical lens 58A associated with the white flood LED 18A, a second optical lens 58B or 58B′ associated with the white spot LED 18B, and a third optical lens 58C associated with the red flood LED 18C. Typically, the optical lens 58A,58B,58B′,58C reflects at least a portion of the light emitted by the corresponding lighting source 18A,18B,18C, wherein at least a portion of the light emitted by the corresponding lighting sources 18A,18B,18C passes through the optical lens 58A,58B,58B′,58C, as described in greater detail herein.
A lens generally indicated at 60A,60B,60C is substantially fixedly coupled to the housing 54. Thus, the optic pack 57A,57B,57C can include the optical lens 58A,58B,58B′,58C and the lens 60A,60B,60C, wherein the corresponding light source 18A,18B,18C can be connected to the LED circuit board 19 and inserted into the corresponding optic pack 57A,57B,57C. According to one embodiment, the optic pack 57A including optical lens 58A,58B,58C and lens 60A is associated with the handheld lighting device 14A, the optic pack 57B including optical lens 58A,58B′,58C and lens 60B is associated with the headlight lighting device 14B, and the optic pack 57C including optical lens 58A,58B,58C and lens 60C is associated with the spotlight lighting device 14C. The lens 60A,60B,60C is a single lens having a portion that is in optical communication with a corresponding light source 18A,18B,18C and corresponding optical lens 58A,58B,58C, according to one embodiment. The lens 60A,60B,60C also includes a plurality of surface configurations, such that at least one surface configuration of the plurality of surface configurations is formed on each portion of the lens 60A,60B,60C to control an illumination pattern of the light emitted from the corresponding lighting source 18A,18B,18C.
According to one embodiment, a first portion 62 of the lens 60A,60B,60C has a first surface configuration that is a flood surface configuration. Thus, the light emitted from the corresponding light source (e.g., white flood LED 18A and red flood LED 18C) and reflected by the corresponding optical lens 58A,58C are directed through the flood surface configuration to produce a flood pattern. Additionally, a second portion 64 of the lens 60A,60B,60C can include a second surface configuration that is a spot surface configuration. Thus, the light emitted from the corresponding light source (e.g., white spot LED 18B) and reflected by the corresponding optical lens 58B′ is directed through the spot surface configuration to produce a spot pattern. According to one embodiment, at least a portion of the plurality of the surface configurations are generally formed by chemically treating the portion of the lens 60A,60B,60C. Typically, at least one chemical agent is applied to the desired portion of the lens 60A,60B,60C surface (e.g., the first portion 62), and the chemical agent alters the surface configuration, which results in the light emitted from the corresponding light source (e.g., white flood LED 18A and red flood LED 18C) to be dispersed at greater angles than the light emitted through a smooth or non-treated portion of the lens 60A,60B,60C (e.g., the second portion 64).
According to one embodiment, the flood beam pattern illuminates a circular target size in diameter of approximately two meters (2 m) or greater at a target distance of approximately one hundred meters (100 m), and the spot beam pattern illuminates a circular target size in diameter of approximately less than one meter (1 m) at a target distance of two meters (2 m). Thus, the flood beam pattern generally illuminates a target size at a first target distance having a greater diameter than the spot beam pattern at a second target distance, such that the light emitted in the flood pattern is emitted at greater angles with respect to the light source (e.g., the white flood LED 18A and red flood LED 18C) than light emitted in the spot pattern. According to one embodiment, the flood beam pattern can be defined as the light being emitted at a half angle of twelve degrees (12°) or greater with respect to the lighting source 18A, and the spot beam pattern can be defined as the light being emitted at a half angle of less than twelve degrees (12°) with respect to the lighting source 18B. Additionally or alternatively, the white LED light sources 18A,18B are CREE XR-E™ LEDs, and the red LED light source 18C is a CREE-XR™ 7090 LED. According to one embodiment, the spot lighting source 18B, and corresponding optic pack 57B, can have a half angle of less than or equal to approximately five degrees (5°) for the handheld and headlight lighting devices 14A,14B, and a half angle of less than or equal to approximately two degrees (2°) for the spotlight lighting device 14C.
For purposes of explanation and not limitation, an exemplary illumination pattern that is emitted by a lighting source 18A,18B,18C is shown in FIG. 17. The illumination pattern has a diameter D at a target, wherein the diameter D corresponds to an angle θ, with which the light is emitted with respect to an optical axis of the lighting source 18A,18B,18C. Thus, the illumination pattern of light emitted by the lighting source 18A,18B,18C can be defined by the size or diameter D of the illumination pattern at the target, the shape of the illumination pattern, the intensity of the light emitted, the angle with which the light is emitted from the lighting source 18A,18B,18C, or a combination thereof. Typically, the light emitted by the white flood LED 18A and red flood LED 18C have a greater size or diameter D at a target, and the light is emitted at a greater angle θ with respect to the optical axis of the lighting source than the white spot LED 18B.
With regards to FIGS. 12A-12C, the optic pack 57A of the handheld lighting device 14A includes the first, second, and third optical lens 58A,58B,58C and the lens 60A. The first portion 62 of the lens 60A,60B, substantially covers and corresponds with the first optical lens 58A and the third optical lens 58C, and the second portion 64 of the lens 60A,60B,60C substantially covers and corresponds with the second optical lens 58B. Thus, the first portion 62 in conjunction with the first optical lens 58A and the third optical lens 58C produce a flood pattern of light emitted by the white flood LED 18A and the red flood LED 18C, respectively. Further, the second portion 64 in conjunction with the second optical lens 58B emit a spot pattern of illuminated light emitted by the white spot LED 18B.
In reference to FIGS. 13A-13C, the optic pack 57B of the headlight lighting device 14B is shown, wherein the optic pack 57B includes the first, second, and third optical lens 58A,58B,58C and the lens 60B. According to one embodiment, the first portion 62 of the lens 60B substantially covers and is associated with the first optical lens 58A and the third optical lens 58C, such that the corresponding white flood LED 18A and red flood LED 18C are directed through the first portion 62 to produce a flood pattern of illuminated light. The second portion 64 of the lens 60A,60B,60C substantially covers and corresponds to the second optical lens 58B, such that light emitted from the white spot LED 18B is emitted through the second portion 64 to produce a spotlight pattern.
With respect to FIGS. 14A-15D, the optic pack 57C of the spotlight lighting device 14C includes the first optical lens 58A, a second optical lens 58B′, the third optical lens 58C, and the lens 60C. The first portion 62 of the lens 60C substantially covers and corresponds to the first optical lens 58A and the third optical lens 58C, such that light emitted from the white flood LED 18A and the red flood LED 18C is emitted through the first portion 62 to produce a flood pattern. The second portion 64 of the lens 60C substantially covers and corresponds to the second optical lens 58B′, such that light emitted by the white spot LED 18B is emitted through the second portion 64 to produce a spot pattern. Additionally, the second optical lens 58B′ that is included in the optic pack 57C of the spotlight lighting device 14C can have a focal point 66 that is deeper with respect to a top 68 that defines an opening 70, wherein light is directed out of the second optical lens 58B′ that is deeper than at least one other focal point of the plurality of optical lenses in the optic pack 57C. Additionally, the second optical lens 58B′ can be a multiple-part optical lens, according to one embodiment. Thus, the multiple parts of the second optical lens 58B′ can be attached to one another to form the second optical lens 58B′ in the final assembly. The multiple parts of the second optical lens 58B′ can be attached by suitable mechanical devices, pressure fitting, adhesives, the like, or a combination thereof. According to one embodiment, the second optical lens 58B′ has a seam 72 that extends circumferentially around the second optical lens 58B′ that separates the second optical lens 58B′ into two parts. According to an alternate embodiment, the second optical lens 58B′ has a seam that extends longitudinally along the second optical lens 58B′ to separate the second optical lens 58B′ into two parts.
According to one embodiment, the optical lenses 58A,58B,58B′,58C are conically shaped reflectors. Specifically, the conically shaped optical lenses 58A,58B,58B′,58C are total internal reflection (TIR) optical lenses, according to one embodiment. The apex (vertex) of each cone shaped optical lens 58A,58B,58B′,58C has a concave surface that generally engages the corresponding LED 18A,18B,18C. By way of explanation and not limitation, at least one of the optical lenses 58A,58B,58B′,58C have a refractive index of 1.4 to 1.7. Additionally or alternatively, the optical lenses 58A,58B,58B′,58C are made of a polycarbonate material, and the lens 60A,60B,60C is made of a polymethylmethacrylate (PMMA) material. Further, the housing 54 can define an indentation 73, as shown in FIGS. 7B, 7C, 8B, 8C, 9B, and 9C, wherein a portion of the lens 60A,60B,60C is inserted in the indentation 73 to fixedly connect the lens 60A,60B,60C to the housing 54, according to one embodiment. Additionally, the first and second potions 62,64 of the lens 60A,60B,60C are optically aligned with the corresponding light source 18A,18B,18C and optical lens 58A,58B,58B′,58C when the lens 60A,60B,60C is inserted into the indentation 73. Alternatively, the lenses 58A,58B,58B′,58C can be, but are not limited to, plano-convex lenses, biconvex or double convex lenses, positive meniscus lenses, negative meniscus lenses, parabolic lenses, the like, or a combination thereof, according to one embodiment.
According to one embodiment, the optic pack 57A,57B,57C can include a central lens section, an outside internal reflection form, a top microlens array, and a small microlens array. Typically, the central lens section can concentrate the light into a range of angles, and the outside internal reflection form can guide the light in the direction the light is to be emitted (e.g., a forward direction). The top microlens array can spread the light into a particular pattern, such as the flood illumination pattern, according to one embodiment. The small microlens array can be used to eliminate a square shape in the illumination pattern, such as for the white spot LED 18B, according to one embodiment.
According to an alternate embodiment, the optic pack 57A,57B,57C is a hybrid of components instead of the embodiment as described above. In this embodiment, the sidewalls of the TIR lens can be reflectors, and a central lens portion can function as spreading optics to spread out the light and form the illumination pattern.

III. Heat Dissipation

With regards to FIGS. 1-4 and 7-9, the lighting devices 14A,14B,14C each include at least one lighting source 18A,18B,18C that generate thermal energy (heat) as a by-product, and the housing 54 that encloses the at least one lighting source 18A,18B,18C generally confines the heat and protects the components therein, according to one embodiment. The housing 54 is in thermal communication with at least one of the lighting sources 18A,18B,18C, such that thermal radiation transfers directly or indirectly from the at least one lighting source 18A,18B,18C to the housing 54. The housing 54 includes a body and a plurality of thermally conductive heat sink fins 74. According to one embodiment, at least a portion of the plurality of thermally conductive heat sink fins 74 extend horizontally with respect to a normal operating position of the at least one lighting device 14A,14B,14C, shown in FIGS. 7A, 8A, and 9A. According to an alternate embodiment, at least a portion of the thermally conductive heat sink fins 74 extend vertically with respect to a normal operating position of the at least one lighting device.
According to one embodiment, the housing 54 is made of a thermally conductive material, such as, but not limited to, thixo molded magnesium alloy, or the like. Additionally or alternatively, at least a portion of the thermally conductive material of housing 54 can be covered with an emissivity coating, wherein the emissivity coating increases the heat dissipation capabilities of the thermally conductive material. According to one embodiment, the emissivity coating can be a material with a heat conductive rating of approximately 0.8, such that the emissivity coating provides a high emissivity and promotes adequate radiant heat transfer. For purposes of explanation and not limitation, the emissivity coating can be, but is not limited to, a DUPONT® Raven powder material. Typically, the emissivity coating is applied to the housing 54 and baked onto the housing 54 after the molding process in order to provide a durable finish.
The thermally conductive heat sink fins 74, whether extending horizontally (FIG. 7A) in one embodiment, vertically (FIG. 7A′) in another embodiment, or a combination thereof, can include at least a first thermally conductive heat sink fin 74A and a second thermally conductive heat sink fin 74B that define an approximately five millimeter (5 mm) spacing 76 between the first and second thermally conductive heat sink fins 74A,74B. In one exemplary embodiment, a horizontal thickness of the thermally conductive heat sink fins 74 can range from and include approximately 0.75 mm to one millimeter (1 mm), and the height of the thermally conductive heat sink fins 74A,74B range from and include approximately four millimeters (4 mm) to 5.8 mm. However, it should be appreciated by those skilled in the art that the above dimensions can be altered to provide a thermally conductive heat sink fin 74 with a greater amount of surface area, which generally dissipates heat with greater efficiency than a thermally conductive heat sink fin with less surface area under substantially the same operating conditions.
According to one embodiment, a thermal conductive gap filler is dispersed between the housing 54 and the LED circuit board 19. The thermal conductive gap filler can generally be selected to have characteristics including, but not limited to, thermal conductivity, adhesive, electrical non-conductivity, the like, or a combination thereof. Thus, the thermal conductive gap filler can be used to conduct heat from the LED circuit board 19 to the housing 54. According to one embodiment, the thermal conductivity of the thermal conductive material is one watt per meter degree of Celsius (W/mC). One exemplary thermal conductive material that can be used as the gap filler is GAP PAD™ manufactured by Bergquist Company. The thermal conductive gap filling material can have an adhesive property, which further forms a connection between the LED circuit board 19 and the housing 54. Typically, the thermal conductive gap filling material is a dielectric material.
At least one temperature monitoring device 50 can be in thermal communication with at least one of the LED circuit board 19 and the housing 54. In one exemplary embodiment, the temperature monitoring device 50 is a thermistor that monitors the temperature of at least one component of the lighting device 14A,14B,14C. By way of explanation and not limitation, the temperature monitoring device 50 can be a positive temperature coefficient (PTC) thermistor, a negative temperature coefficient (NTC) thermistor, or a thermocouple. According to one embodiment, the temperature monitoring device 50 is in thermal communication with at least one other component, such that the temperature monitoring device 50 directly monitors the thermal radiation emitted by the component or a rate of change in the emitted thermal radiation over a period of time. Additionally, the temperature monitoring device 50 communicates the monitored temperature to the processor 36. The processor 36 has hardware circuitry or executes one or more software routine to determine a temperature of at least one other component of the lighting device 14A,14B,14C based upon the monitored temperature. The processor 36 can then alter the electrical power supplied to the at least one light source 18A,18B,18C in order to control the thermal radiation emitted by the light source 18A,18B,18C to the LED circuit board 19. By way of explanation and not limitation, the electrical power can be altered by altering the electrical current, the voltage potential of the electrical power, or a combination thereof.
According to one embodiment, wherein the rate of change of the emitted thermal radiation is monitored, the rate of change of emitted thermal radiation is monitored with respect to a commanded or selected light output function for the lighting source 18A,18B,18C. Thus, the temperature of a component, such as the housing 54, can be determined to a degree by measuring the rate of change of the LED circuit board 19 temperature during a period of time at a specific current output. Typically, the rate of change in the temperature of the component is a function of convection heat transfer (e.g., wind), conduction heat transfer (e.g., the lighting device 14A,14B,14C being held), and radiation heat transfer (e.g., solar radiation).
For purposes of explanation and not limitation, in operation, one of the white flood LED 18A, white spot LED 18B, and red flood LED 18C, or a combination thereof, are illuminated and emit thermal radiation, which is transferred to the LED circuit board 19. According to one embodiment, the temperature monitor device 50 is in thermal communication with the LED circuit board 19, such that the temperature monitor device 50 determines the temperature of the LED circuit board 19. The temperature monitor device 50 communicates the monitored temperature data, which includes, for example, resistance, of the LED circuit board 19 or data to processor 36, wherein the processor 36 determines an approximate temperature of the housing 54 based upon the monitored temperature of the LED circuit board 19. If the monitored temperature or the determined temperature are at or exceed a temperature value, then the processor 36 reduces the electrical power supplied to the white flood LED 18A, white spot LED 18B, red flood LED 18C, or a combination thereof, in order to reduce the amount of thermal radiation emitted by the LEDs 18A,18B,18C.
The temperature value or threshold value that is compared to one of the monitored temperature or the determined temperature can be a temperature value, according to embodiment. The electrical power supplied may be controlled by altering the electrical current supplied to the lighting source 18A,18B,18C, such as by using pulse width modulation (PWM) control. By reducing the electrical power supplied to the LEDs 18A,18B,18C, the thermal radiation emitted by the LEDs 18A,18B,18C is reduced, and the temperature of the LED circuit board 19 and housing 54 is also reduced. Therefore, reducing the electrical power, which reduces the amount of light emitted by the LEDs 18A,18B,18C, results in a temperature controlled lighting device that maintains a selected temperature for the lighting devices 14A,14B,14C.
According to an alternate embodiment, the temperature monitoring device 50 is in thermal communication with the housing 54, such that the thermal monitoring device 50 monitors the temperature of the housing 54. The temperature monitoring device 50 then communicates the monitored temperature of the housing 54 or data to the processor 36, wherein the processor 36 processes the data and determines an approximate temperature of the LED circuit board 19 based upon the monitored temperature of the housing 54. The processor 36 can alter the electrical power supplied to the LEDs 18A,18B,18C based upon the monitored temperature of the housing 54, the determined temperature of the LED circuit board 19, or a combination thereof, in order to reduce the amount of thermal radiation emitted by the LEDs 18A,18B,18C.
Additionally or alternatively, the processor 36 can increase the electrical power supplied to the LEDs 18A,18B,18C based upon a monitored temperature monitored by the temperature monitoring device 50, the determined temperature determined by the processor 36, or a combination thereof, without regard to the component that the temperature monitoring device 50 is in thermal communication with. Typically, the electrical power can be altered by altering the electrical current, which can be controlled by using PWM control. Thus, the supplied electrical power to the LEDs 18A,18B,18C can be increased in order to emit more illumination from the LEDs 18A,18B,18C, when the temperature within the lighting device 14A,14B,14C is maintained at a suitable temperature, such that one of the monitored temperature of the determined temperature are below a second temperature value or threshold value.
With respect to FIGS. 1-4, 7-9, and 16A, a method of controlling the electrical power supplied to the lighting source 18A,18B,18C is generally shown in FIG. 16A at reference identifier 1040, according to one embodiment. The method 1040 starts at step 1042, and proceeds to step 1044, wherein the temperature of a first component is monitored. According to one embodiment, the first component is the LED circuit board 19, which is monitored by the temperature monitoring device 50. According to an alternate embodiment, the first component is housing 54, wherein the temperature of the housing 54 is monitored by the temperature monitoring device 50. At step 1046, an approximate temperature of a second component is determined based upon the temperature monitored at step 1044. According to one embodiment, the second component is either the LED circuit board 19 or the housing 54, wherein the temperature monitoring device 50 is not in direct thermal communication with the second component.
It is then determined at decision step 1048 whether one of the monitored or determined temperature is above a first value. For purposes of explanation and not limitation, when the temperature monitoring device 50 monitors the temperature of the LED circuit board 19, the first value is approximately sixty-six degrees Celsius (66° C.), such that the LED board 19 is operating at approximately sixty-six degrees Celsius (66° C.) and the housing 54 is presumed to have an operating temperature of approximately fifty-five degrees Celsius (55° C.). If it is determined at decision step 1048 that one of the monitored or determined temperature is above the first value, then the method 1040 proceeds to step 1050, wherein the electrical current supplied to the light source 18A,18B,18C is decreased. The method 1040 then ends at step 1052.
When it is determined at decision step 1048 that one of the monitored or determined temperature is not above the first value, then the method 1040 proceeds to decision step 1054. At decision step 1054, it is determined if one of the monitored or determined temperature is below a second value. If it is determined at decision step 1054 that one of the monitored or determined temperature is below the second value, then the method 1040 proceeds to step 1056, wherein the electrical current supplied to the light source 18A,18B,18C is increased. The method 1040 then ends at step 1052.
However, if it is determined at decision step 1054 that one of the monitored or determined temperatures is not below the second value, then the method 1040 proceeds to step 1058. At step 1058, the electrical current being supplied to the light source 18A,18B,18C is maintained, and the method 1040 then ends at step 1052.
With respect to FIGS. 1-4, 7-9, and 16B, a method of controlling the electrical power supplied to the lighting source 18A,18B,18C is generally shown in FIG. 16B at reference identifier 1200, according to one embodiment. The method 1200 starts at step 1202, and proceeds to step 1204, wherein a temperature of a first component is monitored over a period of time. At step 1206, a rate of change of the emitted thermal radiation or monitored temperature is determined. According to one embodiment, the rate of change can be determined based upon comparing the current temperature of the component to a previous temperature of the component. Thus, the temperature of the component is monitored over a period of time. At step 1208, the temperature of a second component is determined based upon the determined temperature rate of change of the first component.
At decision step 1210, it is determined if one of the determined temperature rate of change or determined temperature of the second component is above a first value. If it is determined at decision step 1210 that one of the determined temperature rate of change or determined temperature of the second component is above the first value, then the method 1200 proceeds to step 1212. At step 1212, the electrical current supplied to the lighting source is decreased, and the method 1200 then ends at step 1214.
However, if it is determined at decision step 1210 that one of the determined temperature rate of change or determined temperature of the second component is not above the first value, then the method 1200 proceeds to decision step 1216. At decision step 1216, it is determined if one of the determined temperature rate of change or the determined temperature of the second component is below the second value. If it is determined at decision step 1216 that one of the determined temperature rate of change or the determined temperature of the second component is below a second value, then the method 1200 proceeds to step 1218. At step 1218, the electrical current supplied to the lighting source 18A,18B,18C is increased, and the method 1200 then ends at step 1214.
If it is determined at decision step 1216 that one of the determined temperature rate of change or the determined temperature of the second component is not below the second value, then the method 1200 proceeds to step 1220. At step 1220, the electrical current being supplied to the lighting source 18A,18B,18C is maintained, and the method 1200 then ends at step 1214.
Therefore, the monitored temperature of a component of the lighting device 14A,14B,14C and the determined approximate temperature of other components in the lighting device 14A,14B,14C can be used for controlling different components or devices within the lighting devices 14A,14B,14C.
By way of explanation and not limitation, one exemplary use is to protect the lighting sources 18A,18B,18C from overheating when the lighting sources 18A,18B,18C are LEDs. Typically, LEDs have an LED junction, and it can be undesirable for a temperature of such an LED junction be exceeded for extended periods of time. When the LED junction temperature is exceeded for extended periods of time, the LED life can be shortened. Thus, the monitored and determined temperatures can be used to prevent the LED junction from exceeding a temperature for an extended period of time. Another exemplary use is to maintain the temperature of the housing 54 at a desirable temperature. Thus, by monitoring the temperature of the LED circuit board 19, the approximate temperature of the housing 54 can be determined so that the temperature of the housing 54 can be maintained at a desirable level. A third exemplary use can be to determine an approximate temperature of the internal power source 16, so that the internal power source 16 is operated under desirable conditions, as set forth in greater detail below. It should be appreciated by those skilled in the art that other components, devices, or operating conditions of the lighting device 14A,14B,14C can be controlled based upon the monitored and determined temperatures.
While the invention has been described in detail herein in accordance with certain preferred embodiments thereof, many modifications and change therein may be affected by those skilled in the art without departing from the spirit of the invention. Accordingly, it is our intent to be limited only by the scope of the appending claims and not by way of the details and instrumentalities describing the embodiments shown herein.

Claims

1. A lighting device comprising:

at least one circuit board;

at least one lighting source electronically connected to said at least one circuit board;

a housing enclosing said at least one lighting source and said at least one circuit board, and in thermal communication with said at least one lighting source to dissipate heat generated by said at least one lighting source;

a thermistor in thermal communication with one of said at least one circuit board and said housing to monitor a temperature thereof; and

a controller in communication with said thermistor, wherein said controller performs the steps of:

determining a temperature of the other of said at least one circuit board and said housing not in thermal communication with said thermistor based upon said monitored temperature; and

altering an electrical power supplied to said at least one lighting source based upon said monitored temperature and said determined temperature to maintain at least one of said monitored temperature and said determined temperature below a temperature value associated with said at least one circuit board and said housing, respectively.

2. The lighting device of claim 1, wherein said thermistor is a single thermistor, such that said controller determines said determined temperature based upon a single monitored temperature.

3. The lighting device of claim 1, wherein said thermistor is in thermal communication with said circuit board, such that said thermistor directly monitors thermal radiation emitted from said circuit board.

4. The lighting device of claim 1, wherein said thermistor is in thermal communication with said housing, such that said thermistor directly monitors thermal radiation emitted from said housing.

5. The lighting device of claim 1, wherein said step of altering said electrical power comprises altering an electrical current supplied to said at least one lighting source.

6. The lighting device of claim 1, wherein said housing comprises a plurality of thermally conductive heat sink fins that dissipate thermal radiation communicated to said housing.

7. The lighting device of claim 6, wherein at least a portion of said plurality of thermally conductive heat sink fins extends vertically with respect to a normal operating position of said lighting device.

8. The lighting device of claim 1, wherein said housing comprises an emissivity material that covers at least a portion of said housing.

9. The lighting device of claim 1, wherein said controller increases said electrical power supplied to said at least one lighting source when at least one of said monitored temperature and said determined temperature are below a second temperature value associated with said at least one circuit board and said housing, respectively.

10. The lighting device of claim 1, wherein said monitored temperature is a monitored temperature rate of change.

11. A lighting device comprising:

a plurality of lighting sources;

at least one circuit board are electrically connected to said at least one circuit board electrically connected to said plurality of lighting sources;

a housing enclosing said plurality of lighting sources and said at least one circuit board, and in thermal communication with said plurality of lighting sources to dissipate heat generated by said plurality of lighting sources;

a single thermistor in thermal communication with one of said at least one circuit board and said housing to monitor a temperature thereof; and

determining a temperature of one of said at least one circuit board and said housing not in thermal communication with said thermistor based upon said monitored temperature obtained by said single thermistor; and

altering an electrical current supplied to at least a portion of said plurality of lighting sources based upon said monitored temperature and said determined temperature to maintain at least one of said monitored temperature and said determined temperature below a temperature value associated with said at least one circuit board and said housing, respectively.

12. The lighting device of claim 11, wherein said thermistor is in thermal communication with said circuit board, such that said thermistor directly monitors thermal radiation emitted from said circuit board.

13. The lighting device of claim 11, wherein said monitored temperature is a monitored temperature rate of change.

14. The lighting device of claim 11, wherein said housing comprises a plurality of thermally conductive heat sink fins that dissipate thermal radiation communicated to said housing.

15. The lighting device of claim 11, wherein said housing comprises an emissivity material that covers at least a portion of said housing.

16. The lighting device of claim 11, wherein said controller increases said electrical current supplied to at least a portion of said plurality of lighting sources when at least one of said monitored temperature and said determined temperature are below a second temperature value associated with said at least one circuit board and said housing, respectively.

17. A method of controlling thermal radiation emitted by a lighting device, said method comprising the steps of:

supplying an electrical power to at least one lighting source;

emitting thermal radiation by said at least one lighting source when receiving said electrical power;

monitoring directly a temperature of said emitted thermal radiation of said at least one lighting source;

determining a temperature of a second component based upon said monitored temperature; and

decreasing said electrical power supplied to said at least one lighting source when at least one of said monitored temperature and said determined temperature are above a temperature value associated therewith, respectively.

18. The method of claim 17 further comprising the step of increasing said electrical power supplied to said at least one lighting source when at least one of said monitored temperature and said determined temperature are below a second temperature value associated therewith, respectively.

19. The method of claim 17, wherein said monitored temperature is a monitored temperature rate of change.

20. The method of claim 17, wherein said step of altering said electrical power comprises altering an electrical current supplied to said at least one lighting source.