WO2012151522A1 - Led lamp assembly - Google Patents

Led lamp assembly Download PDF

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Publication number
WO2012151522A1
WO2012151522A1 PCT/US2012/036588 US2012036588W WO2012151522A1 WO 2012151522 A1 WO2012151522 A1 WO 2012151522A1 US 2012036588 W US2012036588 W US 2012036588W WO 2012151522 A1 WO2012151522 A1 WO 2012151522A1
Authority
WO
WIPO (PCT)
Prior art keywords
led
lamp assembly
lamp
cavities
vehicle lamp
Prior art date
Application number
PCT/US2012/036588
Other languages
French (fr)
Inventor
Michael F. Pickholz
Original Assignee
Pickholz Michael F
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US201161518428P priority Critical
Priority to US61/518,428 priority
Application filed by Pickholz Michael F filed Critical Pickholz Michael F
Publication of WO2012151522A1 publication Critical patent/WO2012151522A1/en

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60QARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
    • B60Q1/00Arrangements or adaptations of optical signalling or lighting devices
    • B60Q1/02Arrangements or adaptations of optical signalling or lighting devices the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments
    • B60Q1/04Arrangements or adaptations of optical signalling or lighting devices the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights
    • B60Q1/16Arrangements or adaptations of optical signalling or lighting devices the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights illuminating the way asymmetrically
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60QARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
    • B60Q1/00Arrangements or adaptations of optical signalling or lighting devices
    • B60Q1/02Arrangements or adaptations of optical signalling or lighting devices the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments
    • B60Q1/04Arrangements or adaptations of optical signalling or lighting devices the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights
    • B60Q1/18Arrangements or adaptations of optical signalling or lighting devices the devices being primarily intended to illuminate the way ahead or to illuminate other areas of way or environments the devices being headlights being additional front lights
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60QARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
    • B60Q1/00Arrangements or adaptations of optical signalling or lighting devices
    • B60Q1/26Arrangements or adaptations of optical signalling or lighting devices the devices being primarily intended to indicate the vehicle, or parts thereof, or to give signals, to other traffic
    • B60Q1/2696Mounting of devices using LEDs
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21SNON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S41/00Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
    • F21S41/10Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
    • F21S41/12Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of emitted light
    • F21S41/13Ultraviolet light; Infrared light
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21SNON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S41/00Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
    • F21S41/10Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
    • F21S41/14Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of light source
    • F21S41/141Light emitting diodes [LED]
    • F21S41/151Light emitting diodes [LED] arranged in one or more lines
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21SNON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S43/00Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights
    • F21S43/10Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights characterised by the light source
    • F21S43/13Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights characterised by the light source characterised by the type of light source
    • F21S43/14Light emitting diodes [LED]
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21SNON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S45/00Arrangements within vehicle lighting devices specially adapted for vehicle exteriors, for purposes other than emission or distribution of light
    • F21S45/40Cooling of lighting devices
    • F21S45/47Passive cooling, e.g. using fins, thermal conductive elements or openings
    • F21S45/48Passive cooling, e.g. using fins, thermal conductive elements or openings with means for conducting heat from the inside to the outside of the lighting devices, e.g. with fins on the outer surface of the lighting device
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60QARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
    • B60Q2400/00Special features or arrangements of exterior signal lamps for vehicles
    • B60Q2400/30Daytime running lights [DRL], e.g. circuits or arrangements therefor
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21SNON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S45/00Arrangements within vehicle lighting devices specially adapted for vehicle exteriors, for purposes other than emission or distribution of light
    • F21S45/50Waterproofing

Abstract

A vehicle lamp assembly, comprising a lens, a monolithic lamp housing that cooperates with the lens to at least partially define a lamp chamber that is generally fluidly isolated from an ambient atmosphere, and the lamp chamber subdivided into at least three distinct cavities. At least one LED is provided in each of the at least three distinct cavities. The lamp housing further comprises a heat sink exposed to the ambient atmosphere outside the lamp housing. The heat sink is arranged so that heat generated by the LEDs in any one or more of the at least three cavities of the lamp chamber is dissipated to the ambient atmosphere.

Description

LED LAMP ASSEMBLY
Cross-Reference to Related Application
The present application is related to, and claims the benefit of priority from, United States Provisional Patent Application Serial No. 61 /518,428, filed 4 May 201 1 , the disclosure of which provisional patent application is incorporated herein by reference in its entirety.
Field of the Invention
This invention relates generally to LED lamp assemblies for vehicles, and more particularly to such a lamp assembly configured to dissipate the heat generated by multiple LED light sources provided in the lamp assembly.
Background
Vehicle LED headlamps are rapidly gaining popularity in the marketplace due to numerous factors, including relatively low power consumption, unique technology and styling differentiation aimed to distinguish the offering of any given manufacturer from its competitors. LED headlamp applications have, to date, primarily been implemented in "high-end" vehicles, mainly due to the cost premium associated with the current state of LED headlamp technology. Yet, there is a clear need for lower cost LED headlamp solutions in order to enable implementation of the energy-savings potential of LED lighting technology onto lower cost vehicles, particularly hybrid and electric vehicle models. Reduced power consumption in particular is of singular interest in the quest to reduce fuel consumption, and an overriding concern for electric vehicles where driving with the headlamps on directly translates to reduced range due to the power consumption of the headlamps.
Factors contributing to the cost and mass penalty of seven (7) inch round LED headlamps (designed to fit type 2D1 specifications, also known as Type PAR 56 or 178 mm diameter in non-United States' markets, utilizing the metric equivalent designation to 7 inches) are primarily associated with the significantly higher cost of LED sources versus incandescent/halogen light sources and the intrinsic need to properly cool the LEDs in order to maintain their functional performance characteristics. The deterioration of LED luminous output with increased operating temperatures and the need to prevent operational life reduction and/or premature failure due to excessive operating temperature conditions (which rapidly lead to irreversible deterioration and/or failure) indicates that substantial heat sinks and related systems are required to remove heat from the LEDs and insure they remain within desired operating parameters.
Current seven (7) inch LED headlamp technology employs metal heat sinks, mainly of die-cast aluminum construction as well as, in some cases, internal cooling fans, aimed at bolstering the performance of the headlamp cooling system. The goal therein is to accomplish the effective cooling of the LED(s) via less expensive and lighter weight methodology in order to enhance the energy savings attributes of the LED lamps without introducing negative compromises, such as excess weight and internal cooling systems, which increase overall energy consumption and thus detract from the stated objective of reduced energy consumption. Further efficiencies are sought through the use of high-efficiency reflectors in concert with high efficiency LEDs. For instance, utilizing 17.5 Watt, 1 100 Lumen LED boards, which yields a luminous flux akin to that of a 55 Watt Halogen bulb, yet with a higher optical collection efficiency. Thereby, illuminating capabilities at or above those of conventional Halogen headlamp are achieved, yet with the clear advantage of a combined 35 Watt total power consumption vs. 1 10 Watts for Halogen headlamps, a 68% decrease in power consumption.
Compared with typical high intensity discharge ("HID") sources, which consume 35 Watts each (70 Watts per set), the power consumption is also reduced by 50%. Newer, shortly to be introduced 25 Watt HID lamps will still consume 30% more energy than the proposed LED headlamps. Moreover, forthcoming headlamp LEDs will achieve up to 1800 Lumens with no increase in power consumption, thereby significantly exceeding Halogen performance and, in many cases, that of HID technology as well.
Increased LED lumen output introduces the ability to utilize lower powered LEDs in order to achieve any given level of luminous intensity while accomplishing a further reduction in energy consumption. For instance, the LUMILEDS ALTILON LEDs (Philips Lumileds Lighting Company , California) are currently available in 1 x2 and 1 x4 (i.e. Single LED board with either two (2) or four (4) chips each) and OSRAM-OPTO OSTAR PRO (OSRAM Opto Semiconductors GmbH, Germany) in variants ranging from 1 x2 through 1 x5 LED chips. Hence, with increased LED efficiency and effectiveness, a current 1 x5 chip LED may be substituted with either a 1 x4 or even a 1 x3 chip LED, thereby retaining current performance levels while significantly decreasing power consumption by a further 20% or 40%. High-beam LED operation, which normally only accounts for approximately 6% of headlamp usage, is of significantly lesser import vis-a-vis power consumption. However, high-beam operation is an important safety consideration. Having the ability to retain the low-beam LED in operation, yet bring considerably more luminous flux to bear through the additional output of dedicated high beam LEDs, would significantly enhance illumination performance while entailing no appreciable energy consumption or mass penalty.
Summary of the Disclosure
There is disclosed a vehicle lamp assembly, comprising a lens, and a monolithic lamp housing that cooperates with the lens to at least partially define a lamp chamber that is generally fluidly isolated from an ambient atmosphere. The lamp chamber is subdivided into at least three distinct cavities. At least one LED provided in each of the at least three distinct cavities. The lamp housing further comprises a heat sink exposed to the ambient atmosphere outside the lamp housing, the heat sink arranged so that heat generated by the LEDs in any one or more of the at least three cavities of the lamp chamber is dissipated to the ambient atmosphere.
Per one feature of the present invention, two of the at three distinct cavities are positioned horizontally adjacent to each other so as to share a common intermediate wall, and the third of the at least three distinct cavities is positioned vertically above or below the horizontally-adjacent cavities.
Per another feature, at least one high-beam LED is positioned in each of the horizontally-adjacent cavities, and at least one low-beam LED is positioned in the third cavity.
According to another feature of the present invention, each of the at least three cavities includes a reflector portion adapted to reflect forward through the lens the light emitted by the at least one LED positioned in the cavity. Each reflector portion may, by way of example, comprise a polished surface.
On a further aspect, the confluent area of light reflected from the horizontally- adjacent cavities is positioned in front of the at least one LED provided in the third cavity.
According to yet another feature, the heat sink comprises fins that are exposed to the ambient atmosphere outside the lamp chamber such that heat from the lamp and lamp chamber is transmitted to the ambient atmosphere through the fins.
Per a still further feature, each at least one LED is carried by a circuit board including current paths connected to leads of the LED and connectable to a source of electrical power conditioned to power the LED, the circuit board being carried by the housing.
Per yet another feature, the lamp housing may be formed by any of metal injection molding, thixoforming, plastic injection molding, or die-casting methods.
According to another feature, the lamp housing may be formed from one or more materials selected from the group consisting of stainless steel, low alloy steel, tool steel, titanium, cobalt, copper, magnetic metal, hardmetal, refractory metal, ceramic, plastic, plastic alloy, thermoset plastic, magnesium, aluminum, magnesium/aluminum alloy and zinc.
Per another feature, a bonding agent disposed between the lens and the lamp housing. The bonding agent may include one or more sealants selected from the group consisting of butyl and silicone-based sealants.
In another feature, a sealing element is disposed proximate the interface of the lens and the lamp housing to fluidly seal the lamp assembly at the interface of the lens and the lamp housing.
In one embodiment, at least one of the LEDs provided in each of the at least three distinct cavities is an infrared LED.
Brief Description of the Drawings
These and other features and advantages of the invention will become apparent to those skilled in the art in connection with the following detailed description, drawings, photographs, and appendices, in which:
FIG. 1 is a front view of a lamp assembly according to an exemplary embodiment of the invention;
FIG. 2 is a perspective view of the lamp assembly of FIG. 1 ;
FIG. 3 is a perspective view of the lamp assembly of FIG. 1 , illustrating the relative positioning of the high-beam LEDs of the exemplary embodiment;
FIG. 4 is a perspective view of the lamp assembly of FIG. 1 , illustrating the relative positioning of the low-beam LED of the exemplary embodiment;
FIG. 5 is an end-view of the lamp assembly of FIG. 1 ;
FIG. 6 is a bottom perspective view of the lamp assembly of FIG. 1 , illustrating the heat sink;
FIG. 7 is an end-view of the lamp assembly of FIG. 1 , taken from the direction opposite the end-view of FIG. 5; FIGS 8 and 9 are cross-sectional views of the lamp assembly of FIG. 1 , taken in the directions indicated by the dashed lines in FIG. 1.
Detailed Description
As required, a detailed description of exemplary embodiments of the present invention is provided herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various and alternative forms. The accompanying drawings are not necessarily to scale, and some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a providing a representative basis for teaching one skilled in the art to variously employ the present invention.
Referring more particularly to FIGS. 1 through 9, there is disclosed a vehicle lamp assembly 1 comprising a lens 100 and a monolithic lamp housing 10 that cooperates with the lens 100 to at least partially define a lamp chamber, internal to the lamp housing 10, that is generally fluidly isolated from an external ambient atmosphere. The lamp chamber is subdivided into at least three distinct cavities 11 , 12 and 13. At least one LED 50, 51 and 52 is provided in each of the at least three distinct cavities 11 , 12 and 13, respectively.
Securement of the lens 100, which may be fabricated from any conventional polymeric material, for instance, to the lamp housing 10 may, by way of example, be through a bonding agent disposed between the lens and the lamp housing. Furthermore, the bonding agent may include a sealant to seal the lens assembly relative to the ambient environment. Suitable sealing agents may include, by way of non-limiting example, those selected from the group consisting of butyl and silicone-based sealants.
The lens 100 may be alternatively secured to the lamp housing 10 via mechanical means and sealed to the lamp housing via a sealing element such as, for instance, a gasket (not depicted) or other commonly employed methods.
In one exemplary embodiment, wherein the lamp assembly 10 incorporates LEDs 53 capable of serving as daytime running lights ("DRL"), the lens 100, which has the proper optical characteristics for the DRL function, when incorporated, is placed immediately in front of the LEDs. Further according to this embodiment, lens 100 serves the secondary function of providing requisite light shielding for low-beam LEDs when used as DRLs.
Referring specifically to FIGS. 5, 6, 7 and 9, the lamp housing 10 further comprises a heat sink 20 exposed to the ambient atmosphere outside the lamp housing, the heat sink arranged so that heat generated by the LEDs in any one or more of the at least three cavities 11 , 12 and 13 of the lamp chamber is dissipated to the external ambient atmosphere. According to the illustrated embodiment, the heat sink 20 comprises a plurality of upstanding, parallel-disposed fins 21 that are exposed to the ambient atmosphere outside the lamp chamber such that heat from the lamp and lamp chamber is transmitted to the ambient atmosphere through the fins 21. Still more particularly, it can be seen from the drawings that the fins 21 of the heat sink are arranged across substantially the entire rear surface of the housing 10, such that a heat sink is provided for each of the at least three distinct cavities 11 , 12 and 13 (identified by dashed lines). Of course, the illustrated fins 21 are not meant to be limiting of the constitution of the heat sink 20. Other forms or combinations of forms may be adopted for the heat sink 20, such as those shown and described in published PCT applications WO201 1069012 and WO2010141721 , the disclosures of which are incorporated herein by reference in their entireties.
Referring again to FIGS. 1 through 4, two 12, 13 of the at three distinct cavities are positioned horizontally adjacent to each other so as to share a common intermediate wall 14, and the third 11 of the at least three distinct cavities is positioned vertically above the horizontally-adjacent cavities 12, 13.
Moreover, the at least three distinct cavities 11 , 12 and 13 are configured so that the confluent area of light reflected from the horizontally-adjacent cavities 12, 13 is positioned in front of the at least one LED 50 provided in the third cavity 11.
Each of the at least three cavities 11 , 12 and 13 includes a reflector portion 11 ', 12' and 13' adapted to reflect forward through the lens 100 the light emitted by the at least one LED positioned in the cavity. Each reflector portion 11 ', 12' and 13' may, by way of example, comprise a polished surface, such as illustrated. Alternatively, each reflector portion 11 ', 12' and 13' may comprise one or separate reflective elements secured within the lamp housing. Such reflective elements may, as is known to those skilled in the art, may be fashioned from a suitable metal or polymer which has been polished, chromed, or otherwise coated with a reflective surface. Still further, each reflector portion 11 ', 12' and 13' may comprise a chromed surface of the lamp housing in the region of at least three cavities 11 , 12 and 13.
Given the Lambertian nature of a LED's light distribution, reflectors of the type incorporated onto the inventive headlamp assembly 1 (i.e. ½ of the reflective surface of the lamp) have the demonstrated ability to yield equivalent efficiency as an HID source utilizing a full reflector. Hence, the present invention has the capability to match, or even exceed, the collection efficiency of even the best currently available HID headlamps.
As noted, at least one LED 50, 51 and 52 is provided in each of the at least three distinct cavities 11 , 12 and 13. These LEDs may be carried by one or more circuit boards, as shown, each including current paths connected to leads of the LEDs and connectable to a source of electrical power. The circuit board(s) may be carried by the lamp housing 10, also as shown, or positioned remotely from the lamp housing 10.
Still more particularly, the at least one LED 50 comprises a circuit board positioned on the upper surface of a partition 15 dividing the cavity 11 from the vertically lower cavities 12, 13. Optimally, the at least one LED 50 is positioned close to the surface of the cavity 11 , as depicted, to maximize the dissipation of heat from the cavity 11 to the external ambient atmosphere via the heat sink 20. Moreover, the at least one LED 50 is positioned sufficiently rearwardly in the cavity 11 so that the confluent area of light reflected from the horizontally-adjacent cavities 12, 13 is disposed in front of the at least one LED 50.
As will be appreciated, partition 15 serves as an internal heat sink for heat generated by the LEDs 50, 51 , 52, which heat can be transferred through the lamp housing 10 to the heat sink 20 on the housing exterior.
The LEDs 51 , 52 are arranged on circuit boards that are likewise disposed on the partition 15, although in the case of the LEDs 51 , 52 they are arranged, as shown, on a bottom face of the partition 15. Further, it will be appreciated upon reference to the drawings that the LEDs 51 , 52 are positioned remotely from the center of the partition 14, thereby further separating the LEDs 51 , 52 from the LED 50 in order to further facilitate the dissipation of heat from the chamber of the lamp housing to the outside atmosphere.
Optionally, a set of LEDs 53, serving the function of daytime running lights, may, as also noted above, be provided as part of a circuit board disposed along a forward edge of the partition 15. As these LEDs 53 are turned off whenever any headlamp function (i.e., use of any of the LEDs 51 , 52 and/or 53) is utilized, the thermal mass of the partition 15 can effectively serve as an internal heat sink for the LEDs 50, 51 , 52, and 53.
Optionally, a turn signal function may be provided in the lamp assembly in addition to, or instead of, the LED DRL function 10. This may be accomplished via the substitution or incorporation of additional, suitably colored and performing "amber" (for example) LEDs within the LED array. These LEDs may be positioned, for instance, in or proximate the location of the optional DRL LEDs.
According to the illustrated embodiment, the at least one LED 50 positioned in the third cavity 11 comprises a low-beam LED, while the at least one LED 51 , 52 positioned in each of the horizontally-adjacent cavities 12, 13 comprise high-beam LEDs. For instance, and without limitation, three high-power LED chips of 1800 lumens each may be employed, thereby yielding a total maximum output of 5400 lumens.
While the lamp assembly 1 may be configured with cavities other than as shown, including in an inverted format (i.e., with cavity 11 disposed vertically beneath the horizontally-adjacent cavities 12, 13), the illustrated embodiment is exemplified because low-beam function usage is predominant in typical vehicle operation and current regulations, such as FMVSS 108 in the United States, require that the low beam function be positioned either above or outboard of the high beam function. Thus, a single 17.5 Watt LED may be utilized instead of a 35 Watt HID or, for that matter, a 55 Watt Halogen source. With improved LED illuminating efficiency, lower powered LEDs (such as those identified herein and known to those skilled in the art) may be substituted while still achieving the required photometry and performance expectations. For the high-beam function, although at least one (1 ) additional LED is utilized, with a combined power consumption of 28 Watts, or up to three (3) LEDs with a combined 52.5 Watts (i.e. three (3) 1 x5 chip simultaneously lit LEDs), the overall power consumption remains below that of a single 55 Watt Halogen bulb yet matches or exceeds the illumination provided by 35 Watt HID light sources.
The lamp housing 10 of the present invention is, in the exemplary embodiment, made of metal and may be formed, by way of non-limiting example, by any of metal injection molding, thixoforming, plastic injection molding, or die-casting methods. Without limitation, suitable metals for the manufacture of the lamp housing 10 include those selected from the group consisting of stainless steel, low alloy steel, tool steel, titanium, cobalt, copper, magnetic metal, hardmetal, refractory metal, ceramic, plastic, plastic alloy, thermoset plastic, magnesium, aluminum, magnesium/aluminum alloy and zinc.
Thixoforming (also known as "Magnesium Injection Molding") and other thin-wall magnesium casting techniques are preferred to manufacture the lamp housing 10 from magnesium, as this material and manufacturing techniques confer on the lamp housing 10 the advantage of being, at a minimum, 1/3 lighter than a comparable lamp housing constructed from aluminum. Further, thixoforming and other thin-wall-capable magnesium processes have inherent capabilities, which both enable and further enhance the performance of the final product; namely: Thixoforming yields a 98% density level, far superior to die-casting, which enhances both the mechanical properties as well as the surface finish of the part, particularly in the reflector area. The lack of voids, as well as the high fidelity in the thixoforming process' ability to conform to surface detail, enables the creation of effective, highly polished surface detail necessary to rendering effective reflective surfaces in optical systems. Thixoforming also enables the creation of significantly more detailed, closely-spaced and thinner (approximately 0.5 mm minimum practical wall thickness) elements than possible with die-casting methods, thereby allowing for a significantly greater cooling element (e.g. fins, pins, blades, etc.) density, hence yielding the desired heat sink surface area in a significantly smaller volume.
The unitary thin-wall construction of the inventive lamp assembly 1 maximizes the volume of the lamp chamber and, therefore, enables a significantly larger low-beam reflector area (cavity 11 in the exemplary embodiment), thereby enhancing light collection efficiency and performance. Thin wall construction also enables the relative placement of the low-beam LED(s) 50 at a very short focal length to the reflector, as noted above, thereby further enhancing the light-collecting efficiency of the lamp assembly.
As will be appreciated from this disclosure, the incorporation of twin, distinct high- beam cavities 12, 13 and respective LEDs 51 , 52, coupled with a single low beam cavity 11 and LED(s) 50 achieves the clear separation of the thermal paths for the low beam and high beam LEDs. More particularly, the combination of a single low beam cavity 11 , in conjunction with the twin high beam cavities 12, 13, results in the respective LEDs 50, 51 , 52 being positioned separately so that distinct areas of the lamp housing 10 primarily address the cooling needs for the individual LEDs 50, 51 and 52. This enables all of the LEDs to be lit simultaneously in order to provide more effective high-beam performance via the use of the combined flux of all of the LEDs 50, 51 and 52. Doing so prevents the development of thermal bottlenecks, which can readily result from, for instance, the LEDs being positioned one above the other (e.g. should the lamp housing be divided into just two cavities of similar configuration) or placed in relative close proximity to each other. Such a condition would effectively compromise LED performance due to the inability of the heat sink to effectively dissipate the resulting increase in thermal energy generated by the simultaneous use of two or more LEDs.
Moreover, via the novel configuration of the present invention, the area beneath the low-beam LED 50 of the proposed design is, as disclosed above, close-coupled to the heat sink 21 via a significantly abbreviated thermal path, as the confluent area of both high-beam reflectors takes place geometrically in front of the low-beam LED. This approach significantly reduces the thermal path length for the low-beam LED thereby improving thermal dissipation effectiveness. Furthermore, it places a high density of heat dissipating fins 21 in close proximity to the LED, thereby providing enhanced thermal evacuation properties. The confluent walls of the high beam reflectors 12', 13' also provide additional thermal pathways to other areas of the reflector, thereby further boosting the thermal evacuation properties of the design. Hence, thermal mass is also effectively increased without incurring an actual increase in overall mass for the lamp assembly. Finally, by utilizing thermally dissociated high-beam LEDs 51 , 52, rather than a single LED, enables their concurrent operation with the low-beam LED 50 function, thereby endowing the lamp assembly with exemplary high-beam function performance potential given that all of the at least three LEDs 50, 51 and 52 can be fully powered simultaneously.
One distinctive feature of this lamp housing of the exemplary embodiment that will be appreciated by those skilled in the art is its die-draw construction, whereby no action within the molding tool is required to form any features of the lamp housing as described herein. More specifically, the LED mounting surfaces are tapered outward, towards the front of the lamp, in order to readily facilitate the extraction of the molded part from the mold itself. This construction places the LED mounting surfaces at an angle greater than 180 degrees from the horizontal plane, bisecting the horizontal dividing plane between the upper and lower cavities. And while such a construction would, theoretically, decrease the coupling efficiency of the LEDs and the reflective surfaces, the reflectors are configured to extend sufficiently forward in order to achieve a high degree of optical coupling efficiency and overall performance.
By the foregoing exemplary construction, it will be appreciated that tooling costs are generally lowered and their life expectancy enhanced.
The invention outlines a geometry layout, which permits the positioning of the various LEDs so that their thermal output are channeled to distinct sections of the lamp housing via essentially thermally separate paths, thereby enabling the more efficient cooling of the LEDs without introducing thermal bottlenecks or the need for excessive thermal mass. Furthermore, the prescribed geometry also significantly reduces the effective length of the thermal pass, placing the LEDs in close proximity to the radiating elements of the heat sink (fins in this particular example), which represents a clear thermal dissipation advantage as a shorter thermal path entail a more effective thermal energy dissipation. This reduced thermal path length also contributes to an overall reduction in overall systems mass, a highly beneficial attribute.
For military, as well as other applications where illumination with non-visible light is desired or required (e.g. infrared illumination for "lights out" operation on military vehicles), one of the two (2) high-beam LEDs may be replaced with an infrared ("IR") LED light source or the like. This IR functionality may be powered either separately or in conjunction with the visible light functions heretofore described. This embodiment has the distinct benefits of providing the ability to tailor the IR function lighting to specific "photometric" illumination objectives by explicitly directing the IR LED's output much in the same manner as the reflectors direct and shape the visible LEDs output, in order to create effective illumination beam patterns. In so doing, the IR output is effectively positioned where desired rather than simply being limited to the broadcast nature of the LED other conventional means. Further, incorporation of IR functionality yields a novel, self-contained, lower cost, significantly more rugged and easier-to-install retrofit system, as no additional mounting or housing for the IR function is required. For instance, a retrofit application to an existing vehicle, not previously conceived to accommodate separate IR illumination, may thus be accomplished via a simple, straightforward exchange of an existing 7" 2D1 Headlamp (whether utilizing a conventional tungsten filament construction, halogen bulb, HID or LED light source) for one featuring the embodiments of this invention, requiring no mechanical modifications and only that the electrical/electronic connections for the additional functional features. By virtue of the foregoing, the present invention at once provides a vehicle LED lamp assembly that is relatively inexpensive to manufacture, has a relatively low mass, is easy to install or retrofit to existing vehicles, and is capable of high-performance illumination.
The above description is of the preferred embodiment. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law, including the doctrine of equivalents. Any references to claim elements in the singular, for example, using the articles "a," "an," "the," or "said," is not to be construed as limiting the element to the singular.

Claims

Claims The invention in which an exclusive property or privilege is claimed is defined as follows:
1 . A vehicle lamp assembly, comprising:
a lens;
a monolithic lamp housing that cooperates with the lens to at least partially define a lamp chamber that is generally fluidly isolated from an ambient atmosphere, the lamp chamber subdivided into at least three distinct cavities;
at least one LED provided in each of the at least three distinct cavities; and the lamp housing further comprising a heat sink exposed to the ambient atmosphere outside the lamp housing, the heat sink arranged so that heat generated by the LEDs in any one or more of the at least three cavities of the lamp chamber is dissipated to the ambient atmosphere.
2. The vehicle lamp assembly of claim 1 , wherein two of the at three distinct cavities are positioned horizontally adjacent to each other so as to share a common intermediate wall, and the third of the at least three distinct cavities is positioned vertically above or below the horizontally-adjacent cavities.
3. The vehicle lamp assembly of claim 2, wherein at least one high-beam LED is positioned in each of the horizontally-adjacent cavities, and at least one low-beam LED is positioned in the third cavity.
4. The vehicle lamp assembly of claim 2, wherein each of the at least three cavities includes a reflector portion adapted to reflect forward through the lens the light emitted by the at least one LED positioned in the cavity.
5. The vehicle lamp assembly of claim 4, wherein each reflector portion comprises a polished surface.
6. The vehicle lamp assembly of claim 4, wherein confluent area of light reflected from the horizontally-adjacent cavities is positioned in front of the at least one LED provided in the third cavity.
7. The vehicle lamp assembly of claim 1 , wherein the heat sink comprises fins that are exposed to the ambient atmosphere outside the lamp chamber such that heat from the lamp and lamp chamber is transmitted to the ambient atmosphere through the fins.
8. The vehicle lamp assembly of claim 1 , wherein each at least one LED is carried by a circuit board including current paths connected to leads of the LED and connectable to a source of electrical power conditioned to power the LED, the circuit board being carried by the housing.
9. The vehicle lamp assembly of claim 1 , wherein the lamp housing is formed by metal injection molding.
10. The vehicle lamp assembly of claim 1 , wherein the lamp housing is formed by thixoforming.
1 1 . The vehicle lamp assembly of claim 1 , wherein the lamp housing is formed by plastic injection molding.
12. The vehicle lamp assembly of claim 1 , wherein the lamp housing is formed by casting methods.
13. The vehicle lamp assembly of claim 1 , wherein the lamp housing is formed from one or more materials selected from the group consisting of stainless steel, low alloy steel, tool steel, titanium, cobalt, copper, magnetic metal, hardmetal, refractory metal, ceramic, plastic, plastic alloy, thermoset plastic, magnesium, aluminum, magnesium/aluminum alloy and zinc.
14. The vehicle lamp assembly of claim 1 , further comprising a bonding agent disposed between the lens and the lamp housing.
15. The vehicle lamp assembly of claim 14, wherein the bonding agent includes one or more sealants selected from the group consisting of butyl and silicone-based sealants.
16. The vehicle lamp assembly of claim 1 , wherein at least one of the LEDs provided in each of the at least three distinct cavities is an infrared LED.
17. The lamp assembly of claim 1 , further comprising a sealing element disposed proximate the interface of the lens and the lamp housing to fluidly seal the lamp assembly at the interface of the lens and the lamp housing.
PCT/US2012/036588 2011-05-04 2012-05-04 Led lamp assembly WO2012151522A1 (en)

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US61/518,428 2011-05-04

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016127236A1 (en) * 2015-02-13 2016-08-18 Balbinot Mauricio Structural arrangement in modular vehicle headlights of the bi-led type
WO2016127237A1 (en) * 2015-02-13 2016-08-18 Balbinot Mauricio Structural arrangement in modular vehicle headlights
EP3290782A1 (en) * 2016-09-02 2018-03-07 Valeo Lighting Hubei Technical Center Co Ltd Lighting device for motor vehicle and manufacturing method thereof
WO2018213454A1 (en) * 2017-05-17 2018-11-22 Battelle Memorial Institute Universal dual infrared and white light bulb
US10190740B2 (en) 2013-05-31 2019-01-29 Panasonic Intellectual Property Management Co., Ltd. Light source unit and vehicle front lamp using the light source unit

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US6443592B1 (en) * 1999-02-06 2002-09-03 Wila Leuchten Ag Luminaire having annular inner housing with detachable annular louver support element
US20090003009A1 (en) * 2007-06-30 2009-01-01 Thomas Tessnow LED lamp module
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Publication number Priority date Publication date Assignee Title
US6443592B1 (en) * 1999-02-06 2002-09-03 Wila Leuchten Ag Luminaire having annular inner housing with detachable annular louver support element
US20090003009A1 (en) * 2007-06-30 2009-01-01 Thomas Tessnow LED lamp module
US20100020548A1 (en) * 2007-11-27 2010-01-28 Abl Ip Holding Llc In-grade lighting system

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10190740B2 (en) 2013-05-31 2019-01-29 Panasonic Intellectual Property Management Co., Ltd. Light source unit and vehicle front lamp using the light source unit
WO2016127236A1 (en) * 2015-02-13 2016-08-18 Balbinot Mauricio Structural arrangement in modular vehicle headlights of the bi-led type
WO2016127237A1 (en) * 2015-02-13 2016-08-18 Balbinot Mauricio Structural arrangement in modular vehicle headlights
EP3290782A1 (en) * 2016-09-02 2018-03-07 Valeo Lighting Hubei Technical Center Co Ltd Lighting device for motor vehicle and manufacturing method thereof
WO2018213454A1 (en) * 2017-05-17 2018-11-22 Battelle Memorial Institute Universal dual infrared and white light bulb
US10781985B2 (en) 2017-05-17 2020-09-22 Battelle Memorial Institute Universal dual infrared and white light bulb

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