The present invention relates to light emitting devices. More particularly, the present invention relates to light emitting device modules and lighting devices.
Incandescent light bulb emits visible light when electrical current passes through its resistor wire (typically tungsten) to heat it up till it glows and radiates light. A typical incandescent light bulb emits 22 Lumens of light per watt of energy absorbed by the resistor wire. The resistor wire is eventually burned off after an average of 750 hours. Incandescent light typically produces a spectrum of Red, Green and Blue lights. CRI (Color Rendering Index) is used to describe spectrum of color, 1 being perfect while zero being the worst. Incandescent light has a CRI better than 0.9 while fluorescent is around 0.5-0.7 meaning an object's actual color was 50%-70% illuminated by the light, e.g. a red object may appear to be burgundy rather than its actual red color. HID (High Intensity Discharge) sodium light is amber light that has a very low CRI; as such most colors under its illumination appear to be of different colors.
Fluorescent light is produced by passing electricity to excite mercury vapor inside a vacuum tube to produce UV (Ultraviolet) radiation which in turn causes a phosphor powder coated on the walls of the tube to fluoresce, producing visible light. Fluorescent light bulb produces more light output and last much longer than Incandescent light bulb. But, its disadvantages are low CRI meaning and it contains hazardous chemicals such as mercury which is known to retard brain development in young people or to cause certain cancers. Disposal of Fluorescent light bulb has become an environmental problem in the world today as its hazardous chemicals post serious health threat if the hazardous chemical is air borne and inhaled by human.
HID (High Intensity Discharge) light, also referred to as Arc Lamp, uses electricity to produce electric arc between its tungsten electrodes housed inside a translucent quartz tube that is filled with both gas and metal salts. The arc evaporates the metal salts to form plasma which greatly increase the intensity of light produced by the arc. HID produces more visible light than incandescent and fluorescent lights. However, its disadvantages are similar to fluorescent light as it yields very low CRI and contains hazardous chemicals such as sodium or mercury. Examples are High or Medium Pressure Sodium Light which produce only amber color light that are commonly used to illuminate streets or highways.
Light emitting diode (LED) light bulbs are superior to all of the light bulbs produced by the above light sources. With very fast advance in LED semiconductor chip technology, an LED chip can produce more than 125 Lumens per watt of neutral white light with 80 percent CRI and 100 lumens of warm white light with 90 percent CRI.
Also, LED has a much longer life span than all the other light sources. LED light retains 70 percent of its initial brightness after 50,000 hours of operation under normal conditions. When lighted for 24 hours a day with the usual electrical current, its life span is 10 years.
Approximately twenty percent of the total energy used worldwide is for lighting; and the lights used are incandescent, fluorescent and HID but very few LED at this present moment. As LED light can save at least fifty percent energy used for lighting, it is important to save the world's energy consumption by changing all lights to LED. Potentially, LED can save at least ten percent of the world total energy usage and this is millions of barrels of petroleum or tens of nuclear plants that need to be built in the next few years.
However, because of complexity and difficulties encountered in the design and thermal solution needs to retrofit of LED light source replacing the other light source, adaptation of LED light has been extremely slow. Further, many LED street lights, for example, failed within a year—due to poor thermal design in the fixture—hence scaring off many potential users.
Accordingly, there remains a need for an LED lighting device that can retrofit the existing fixtures and luminaires, to deliver its expected performance and life expectancy, with a much lower initial cost.
The need is met by the present invention. In the first embodiment of the present invention, a lighting device includes a body, a platform where at least one LED module is mounted, and heat fins on the body. The body defines side opening through which the light from the LED module exits. A lens covers the side opening. A reflector is placed proximal to the side opening to reflect light from the LED module in a desired direction. The body has a tubular shape and defines a first and a second end. A thermal end cap covers the first end of the body. An Edison screw cap covers the second end of the body. A sleeve is coupled to the second end of the body. A screw adaptor is fitted or rotatably engaged to the sleeve and can turn relative to it. The screw adaptor defines a groove track. A dowel pin engages the sleeve and riding along the groove track when turning. A set screw engages the sleeve providing a locking mechanism.
The lighting device has a tubular shape having a first end and a second end. The first end is covered by an end cap and the second end is terminated or covered by an Edison screw cap. At least one heat foil may be is connected to the body, the heat foil providing additional heat dissipation surface. The heat foil is coupled to the body along a groove defined by the heat fins of the body. A retaining bar may be inserted along the groove to press the heat foil against to the body, thus conducting heat out from the body. One or more circuit boards may be provided within the lighting device for mounting electrical components.
In a second embodiment of the present invention, a lighting device includes a light bulb and an external heat sink. The side emitting light bulb includes a body defining a side opening and having an external surface. At least one LED module is placed within the body. The LED module can be powered up by electrical current to emit light and heat is generated as a result. An external heat sink is connected to the light bulb, the external heat sink having a plurality of heat fins. A heat pipe is connected to the body of the light bulb. A heat adaptor is connected to the heat pipe. And a heat bolt is connected to the heat adaptor and the external heat sink. The heat pipe includes a close-end tube which contains cooling fluids that can transport heat from a hot end to a cold end at a much faster than pure copper, for example. The light bulb has a platform where the LED module is mounted. The platform is bonded to said body for heat dissipation. The body includes heat fins on its external surface, the heat fins increasing the surface area of the body for increased heat dissipation.
In a third embodiment of the present invention, luminaire includes a light bulb, a housing enclosing the light bulb, an external heat sink thermally connected to the light bulb, and a heat pipe connecting the light bulb with the external heat sink. A heat adaptor connects the heat pipe. A heat bolt connects to the heat adaptor and the external heat sink. The housing defines an opening through which the heat bolt passes to connect the heat adaptor, enclosed within the housing, to the external heat sink, external to the housing. A sleeve is coupled to the body. A screw adaptor is rotatably engaged to the sleeve. The screw adaptor defines a groove track. A dowel pin engages the sleeve and riding along the groove track. A set screw engages the sleeve providing a locking mechanism. The housing includes an Edison socket adapted to engage the Edison screw threads.
In a forth embodiment of the present invention, a luminaire includes a light bulb, a housing enclosing the light bulb, and at least one heat foil couple to the light bulb. The heat foil extends beyond the housing allowing heat from the light bulb to dissipate outside the housing. The light bulb includes a body having heat fins, the heat fins forming grooves where the heat foil couples with the light bulb.
The present invention is described with reference to the
Each of the incorporated documents (including provisional applications and non-provisional applications) includes drawings and specifications having figure designations, reference numbers, and their descriptions. To preserve consistency, some (but not all) figure designations, reference numbers, or both (of one or more of the incorporated documents) are used in the present document for portions or structures of various embodiments that corresponds to identical or similar portions or structures of embodiments disclosed by the incorporated documents. However, in general, to avoid confusion and to describe the inventions with even more clarity, in this document, figure designations, reference numbers, and their descriptions are independent from and of the incorporated documents. To avoid duplication and clutter, and to increase clarity, in the Figures, not every referenced portion is annotated with its reference number in every Figure.
The invention is disclosed in the following example embodiments: a first embodiment of a side emitting light bulb (SELB) illustrated in
Body 2820 (
Referring to
The Body 2820 is equipped with a plurality of external Heat-fin 2822 on its external surface; the Heat-fin 2822 draws heat from Body 2820. The Heat-fin 2822 provides a greater external surface area and can dissipate heat efficiently to its surrounding air by convection. Also, heat from the Heat-fin 2822 and the Body 2820 can be drained away by any thermally conductive material or device which makes good contact with either or both of these. The Heat-fins 2822 are made of thermally conductive material. The Heat-fins 2822 can be made to any shape to serve other purposes such as, for example, engaging with other components, for example, a lens, an external heat-sink, etc. Reference number 2822 indicates heat fins in general. Particular heat fins with additional functions are indicated with reference number 2822 followed by a letter such as, for example, 2822A, 2822B, or 2822C. The Heat-fin 2822 and the Body 2820 can be easily made by Aluminum extrusion.
Body 2820 may be machined to a suitable length and to define a side opening 2823 on its side to allow light emitted by the LED modules 1000 to exit the Body 2820. The opening 2823 of the Body 2820 may be covered with a lens 2805, also referred to as a lens cover 2805.
In the illustrated sample embodiment, the lens 2805 is made of a transparent plastic or glass and is so shaped to cover the opening 2823 of the Body 2820. The lens 2805 may be clear, colored, diffused, or textured to scatter lights. The lens 2805 may be secured to the Body 2820 by means of an adhesive or by some mechanical fixture. The lens 2805 is engaged to the Body 2820 by a mounting hook 2822A, the mounting hook 2822A being a special hook feature. The mounting hook 2822A also provides protection for edges of the lens 2805. This is most clearly illustrated in
In the illustrated sample embodiment, the Body 2820 having a tubular shape defines a hollow interior within which various structures may be provided. For example, a platform 2821 is placed inside the Body 2820 for mounting one or more LED modules 1000. The platform 2821 is either an integral part or, if a separate item, can couple to the Body 2820 by soldering or thermal adhesive. Light from the LED modules exits the SELB 2800 through the opening 2823. For example, two LED modules 1000 are illustrated in the drawings. However, in the present invention any number of LED modules may be mounted within the Body 2820.
Reflector 2804 (
The SELB 2800 also includes a Reflector 2804 positioned proximal to or within the opening 2823 to reflect light from the LED modules 100 toward a desired direction. The reflector 2804 may be made by stamping or forming on any thin reflective sheet of metal or plastics, for example only, Alanod or Lorin which has more than 86 percent reflectance. The reflector 2804 may also be molded with plastic, followed by coating with reflective materials such as metal Aluminum or Silver. In addition, the Reflector 2804 may be made by a plastic material, for example, Amodel (trade name of a high temperature engineering plastics which is filled with highly reflective power such as Titanium Dioxide.
Thermal End-Cap 2806 (FIG. A, 2C, 2D)
A thermal end-cap 2806 covers a first end of the tubular shaped the Body 2820. The end-cap 2806 also may be used to mount or connect SELB 2800 to other components as illustrated in
Rotating Edison Screw Cap 2810 (
The second end of the Body 2820 is fitted with an Edison screw-cap 2810, for example, E27, E39 or other types, to enable the SELB 2800 to be screwed onto an Edison electrical socket which supplies electrical power. The Edison screw cap 2810 can bottom out in the Edison electrical socket having the SELB 2800 facing a direction that may not be desired. Therefore, the SELB 2800 can be rotated about its axis such that the Lens 2805 to face any direction as desired. Because of this flexibility, the SELB 2800 can be screwed into any socket while the light emitting from it can be adjusted to face any direction. The Edison screw cap 2810 defines the screw threads 2813.
To provide for rotational adjustability, the screw cap 2810 includes a screw adaptor 2811 defining a groove track 2811G. A sleeve 2812, attached to the Body 2820, rotationally engages the screw adaptor 2811. A Dowel pin 2812P rides inside the groove 2811G to limit the relative rotation between the sleeve 2812 and the screw adaptor 2811 to a rotational angle, for example 350 degrees, that is less than a full turn (360 degrees); without the rotational limit, internal wires (not shown) connecting the Edison cap 2810 to the LED modules 100 may be tangled.
The relative rotational position of the Body 2820 with respect to the screw cap 2810 is locked by one or more set screws 2812S. A maximum adjustable angle in the rotating mechanism may be limited to less than a full turn (360 degrees), for example, 350 degrees.
The SELB 2800 may also house components such as, for example only, electrical printed circuit boards 2506. Often, the circuit boards 2506 include driver circuits for regulating the input electrical to a suitable electrical power that power the LED modules 1000.
Heat Sink 2913
Referring to
Heat-Pipe 2910
A thermal transport device connects the SELB 2800 at one end to the Heat-sink 2913 at the opposite end. The Heat-pipe 2910 can be made of closed end or hollow copper or aluminum tube filled with fluids such as water, alcohol which are then vacuum sealed inside. Because of vacuum, fluids can evaporate at very low temperature quickly thus absorbing heat from the SELB 2800 and then condensate at the cool end at the Heat-sink 2913. A heat adaptor 2911 and a bolt 2912 (heat conductor bolt) are designed to fasten the Heat-pipe 2910 thermally to the heat sink 2913. Meanwhile, the opposite end of the Heat-pipe 2910 can be thermally fastened to the End-cap 2806 of SELB 2800 by means of cap cover 2806B (a flange) and screws 2806C. Alternately, thermal adhesive can in place screws. By this arrangement, heat generated by the LED module 1000 inside the SELB 2800 flows effectively to the Heat-sink 2913 which dissipates it efficiently.
Heat-Adaptor 2911
The Heat-adaptor which connects Heat-pipe 2910 to the external Heat-sink 2913 can also be thermally fastened to the Body of a lighting fixture to allow heat to transfer to the fixture which can aid in dissipate heat also.
Most existing luminaires designed for Incandescent, Fluorescent or HPS lights normally trap heat inside because all the standard light sources, for example, Incandescent, HID, etc., perform relatively well under hot environment. Whereas when LED light source is installed in these fixtures, heat should be removed from inside the fixture otherwise, the LED will fail due to of heat. Hence, the second embodiment is specially designed to remove the heat from inside of a luminaire.
Referring to
In the existing art, the luminaire housing 2710 is often painted with polyester or epoxy paint which has a very poor thermal conductivity. Accordingly, heat dissipation capacity of the housing 2710 is less than often desired. In the present invention, the external heat sink 2913 (external to the housing 2710), thermally connected to the SELB 2800 (enclosed within the housing 2710), provides for increased heat dissipation capacity for the Luminaire 2700.
Referring to
The bolt 2912 may be straight or bent in any shape to pass through the housing 2710 of the luminaire 2700. Alternatively, the bolt 2912 may be a taper bolt which fits with a corresponding taper hole in the housing 2710 of the luminaire 2700. Thermal grease on various contact points between the SELB 2800, the heat pipe 2910, the heat adaptor 2911, the heat bolt 2912, and the external heat sink 2913, increases heat transfer efficiency between these components. The connection of the bolt 2912 and the heat-sink 2913 may also be achieved by means of screw threads, a press or a taper fit to minimize thermal resistance at the interface.
Referring to
Heat Foil 2829
The heat foil 2829 may be made of thin sheet metal such as Copper or Aluminum, or alloys of thermal conductive materials. The thickness of the heat foils 2829 may range from tens of micrometers to several hundreds of micrometers. The heat foils 2829 may be formed or shaped to fit with minimal thermal resistance to the Body 2820. When the SELB 2800 is installed inside an enclosure, the heat foils 2829 may extend beyond the enclosure such that heat can flow from the SELB 2800 to outside the enclosure and be dissipated. Another advantage of the heat foil 2829 is that it may also function as an optical reflector if it is made of reflective sheet material.
Referring to
The present invention as disclosed in various sample embodiments illustrated in the Drawings and discussed herein may be used in general lighting applications such as, for example only and without limitations, light bulbs, lighting luminaires, street lights, highway lights, parking lights, industrial lighting, and many others. The present invention as disclosed in various sample embodiments illustrated in the Drawings and discussed herein may be used to replay light sources such as incandescent, fluorescent, HPS, LPS, halogen light bulbs or modules.
The present invention as disclosed in various sample embodiments illustrated in the Drawings and discussed herein include at least three thermal solutions—first, the device's own body has heat fins with large surface areas for heat dissipation by convection; second, a heat transport device extracts heat from the body and transports the heat to an external heat sink; and third, a flexible heat foil that may be coupled to the body to increase heat dissipation surface as well as to extend the heat dissipation surface beyond any enclosures.
From the foregoing, it will be appreciated that the present invention is novel and offers advantages over the existing art. Although a specific embodiment of the present invention is described and illustrated above, the present invention is not to be limited to the specific forms or arrangements of parts so described and illustrated. For example, differing configurations, sizes, or materials may be used to practice the present invention.
This patent application claims the benefit of and priority under 35 USC sections 119 and 120 to U.S. Provisional Patent Application Ser. No. 61/480,646 filed Apr. 29, 2011. The Application 61/480,646 is incorporated herein by reference in its entirety. Further, this patent application claims the benefit of and priority to U.S. patent application Ser. No. 13/163,437 filed on Jun. 17, 2011. This patent application, being a continuation-in-part of application Ser. No. 13/163,437, incorporates by reference application Ser. No. 13/163,437 in its entirety. Further, this patent application claims the benefit of and priority to U.S. patent application Ser. No. 13/019,900 filed on Feb. 2, 2011. This patent application, being a continuation-in-part of application Ser. No. 13/019,900, incorporates by reference application Ser. No. 13/019,900 in its entirety.
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Number | Date | Country | |
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Parent | 13163437 | Jun 2011 | US |
Child | 13456869 | US | |
Parent | 13019900 | Feb 2011 | US |
Child | 13163437 | US |