Patent Application
20090189549
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.
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.
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.
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
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;
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.
In reference to
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 (
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
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
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
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
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
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.
In regards to
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
With regards to
In reference to
With respect to
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
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.
With regards to
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 (
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
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
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.
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.
| Number | Date | Country | |
|---|---|---|---|
| 61023632 | Jan 2008 | US |
