Patent Publication Number: US-10323800-B2

Title: Retrofit LED lamp fixtures

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/081,581, filed Mar. 25, 2016, entitled “retrofit LED lamp fixtures,” issued Nov. 6, 2018, as U.S. Pat. No. 10,119,659, which claims the benefits of U.S. Provisional Patent Application No. 62/139,638, filed Mar. 27, 2015, entitled “retrofit LED lamp for fixtures,” All above-identified patents and patent applications are hereby incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to Light Emitting Diodes (LED) retrofit lighting and more specifically to a platform for new fixtures as well as a solution for existing fixtures by replacing conventional light bulbs with LED lamps. 
     BACKGROUND 
     In the pursuit of energy efficiency, LED based lighting products are rapidly replacing incandescent and filament based light bulbs, among others. There is currently no structurally suitable LED replacement for the standard Par64 and Par56 light bulbs most widely used in entertainment venues, studios and sets, theaters, concert halls and convention centers. The current bulbs installed in many fixtures are energy inefficient, have a short lifespan and generate significant waste heat. While substitute LED lamps are available for lighting fixtures for other applications, such as the home or office, none exist for the “work horse” fixture in the professional lighting market. There is no structurally suitable LED lamp for standard fixtures that use Par56 and Par64 conventional bulbs. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a perspective view of one embodiment of the present invention in a four LED, center mounted fan arrangement with a vented front cover shown both on and off for interior layout view. 
         FIG. 2  is a front view and side view of the four LED, center mounted fan layout, with the front cover removed, in accordance with one embodiment. 
         FIG. 3  is an exploded perspective view of the four LED, center mounted fan layout, in accordance with one embodiment. 
         FIG. 4  is a perspective view of one embodiment of the present invention in a two LED, center mounted fan arrangement with a vented front cover shown both on and off for interior layout view. 
         FIG. 5  is a front view and side view of the two LED, center mounted fan layout, with the front cover removed, in accordance with one embodiment. 
         FIG. 6  is an exploded perspective view of the two LED, center mounted fan layout, in accordance with one embodiment. 
         FIG. 7  is a perspective view of one embodiment of the present invention in a two LED, offset mounted fan arrangement with a vented front cover shown both on and off for interior layout view. 
         FIG. 8  is a front view and side view of the two LED, offset mounted fan layout, with the front cover removed, in accordance with one embodiment. 
         FIG. 9  is an exploded perspective view of the two LED, offset mounted fan layout, in accordance with one embodiment. 
         FIG. 10  is a perspective view of one embodiment of the present invention in a two LED, offset mounted fan arrangement with custom LED optics and a vented front cover shown both on and off for interior layout view. 
         FIG. 11  is a front view and side view of the two LED, offset mounted fan layout, with custom LED optics and the front cover removed, in accordance with one embodiment. 
         FIG. 12  is an exploded perspective view of the two LED, offset mounted fan layout with custom LED optics, in accordance with one embodiment. 
         FIG. 13  is a perspective view of one embodiment of the present invention in a single LED, rear mounted fan, radial heat sink arrangement with a vented front cover shown both on and off for interior layout view. 
         FIG. 14  is a front view and side view of the single LED, rear mounted fan, radial heat sink layout, with the front cover removed, in accordance with one embodiment. 
         FIG. 15  is an exploded perspective view of the single LED, rear mounted fan, radial heat sink layout, in accordance with one embodiment. 
         FIG. 16  is a perspective view of one embodiment of the present invention in a single LED, rear mounted fan, linear heat sink arrangement with a vented front cover shown both on and off for interior layout view. 
         FIG. 17  is a front view and side view of the single LED, rear mounted fan, linear heat sink layout, with the front cover removed, in accordance with one embodiment. 
         FIG. 18  is an exploded perspective view of the single LED, rear mounted fan, linear heat sink layout, in accordance with one embodiment. 
         FIG. 19  is a diagram of delayed application of mains power when dimming. 
         FIG. 20  is a block diagram of an example embodiment of the power supply. 
         FIGS. 21-25  are block diagrams of example embodiments of power supply schematics. 
     
    
    
     In the drawings, elements having the same designation have the same or similar functions. 
     DETAILED DESCRIPTION 
     In the following description specific details are set forth describing certain embodiments. It will be apparent, however, to one skilled in the art that the disclosed embodiments may be practiced without some or all of these specific details. The specific embodiments presented are meant to be illustrative, but not limiting. One skilled in the art may realize other material that, although not specifically described herein, is within the scope and spirit of this disclosure. 
     The present invention addresses the undesirable qualities related to the use of conventional bulbs. Conventional bulbs are high in energy consumption due to their inefficiency. Further, conventional bulbs generate a significant amount of heat that radiates from the bulb. This can damage filtering gel sheets affixed to the fixture opening that are used to produce a monochromatic color other than white. This heat is often sufficient to make the fixture untouchable during operation and may also increase building energy costs used for ambient air conditioning. These conventional bulbs may also radiate some light through the back of the fixture causing undesirable effects when, as is often the case, light pattern control is necessary. 
     A suitable LED based replacement lamp should fit into existing fixtures and work with existing lighting control equipment without requiring any changes to wiring. The light pattern, dimming response and color temperatures should be indistinguishable from the conventional bulb. 
     Similarly, a hybrid or new platform of lighting fixtures can be based on a LED solution. In a hybrid arrangement, conventional bulbs are replaced with LED lamps and new additional fixtures use a LED-only lamp. In a new platform, the invention fits into a fixture designed to house it and allow it to be used as in the same manner, for example as the Par64 and Par56 fixtures. It furnishes an equivalent adjustable yoke, base and connectivity for an LED PAR. 
     The present invention provides an LED component based retrofit lamp for conventional bulbs used in associated fixtures that when installed, requires little or no modification to the fixture. The invention is fully compatible with existing wiring and power connections as well as lighting control and dimming equipment while achieving equivalent light output and color temperature. For example, in one embodiment the conventional bulbs that are replaced are Par64 and Par56 bulbs. 
     In addition, the present invention can be fully compatible with existing infrastructure and fixtures and may embody new fixtures. For example, in one embodiment, the invention can be installed into standard Par64 and Par56 fixtures. Alternatively, in another embodiment, the invention can be the core of a new fixture. This embodiment can be functional with existing infrastructure such as control equipment and wiring and may require minimal changes or upgrades to these set-ups. 
     In retrofit form, the form factor and package of the present invention fits in the same space as the conventional bulb it replaces and installs in a similar manner. The entire LED PAR is designed to be compatible with standard, commercially available fixtures that were originally designed to accept conventional bulbs, such as incandescent bulbs. Different embodiments of the present invention correspond to various sizes, such as the 8 inch, Par64 size or the 7 inch, Par56 size. In one embodiment, this is achieved using a solid 8 inch or 7 inch diameter plate. As an additional benefit the use of a plate minimizes light leakage including the light produced from the LED element that would otherwise radiate out of the back of the lighting package. The electrical connection to the LED PAR is compatible with current industry standard plugs. It is compatible with the same power provided to the conventional bulb it replaces with no change to voltage levels, phase or frequency. 
     The entire LED PAR may be cooled with forced convection and a suitable heat sink. For example, in one embodiment, air is passed over the heat sink drawn from the front of the fixture and exhausted out the back by a fan. This creates an efficient pass-through cooling method. 
     The LED PAR is equipped with network software and hardware that supports remote network services and allows for remote connectivity. The LED PAR runs network services that allow a user to monitor and control the device. Monitoring services include the ability to monitor service hours, current temperature, maximum temperature level reached and other pertinent status information. This information is transmitted wirelessly using a network protocol such as IP, RFID, HTTP, HTTPS or other suitable network protocol for remote monitoring and logging. 
     The form factor of the package allows for a field-replaceable power supply unit, separable from the other components. This maximizes the useful lifetime of the LED components, heat sink and cooling elements. All forms are designed so that the LED PAR fits into the fixture in a similar manner as the conventional bulb it replaces. 
     The LED PAR provides a mounting surface  16  for high powered LED emitter arrays  28  in a single, dual or quad configuration.  FIGS. 1 through 18 , as previously described and provided below, detail alternate embodiments of layouts, component arrangements and cooling solutions. Each design layout is necessary and different to provide the range of light outputs the LED PAR is designed to achieve for market expectations. The mounting plate  16  may come in two distinct sizes, a 7-inch and an 8-inch diameter of stamped or cut aluminum for the purposes of heat sinking. The LED arrays  28  are attached directly to this plate using holders  26  providing maximum thermal transmission. In another embodiment the form factor utilizes a plastic plate of the same two diameters. Other variations, e.g.  FIG. 13  and  FIG. 16 , leave a cutout in the plate wherein the LED arrays are installed directly to a heat sink. 
     The LED PAR utilizes a heat sink  30 . In one embodiment it is a linear straight fin heat sink (e.g.  22  in  FIG. 3 ), which is either machined, extruded, die cast, cold forged or made from bonded fins or folded fins. In another embodiment it is a heat sink of a radial design (e.g.  FIG. 15 ) that is either machined, die cast, or cold forged. This part is manufactured from various combinations of aluminum, aluminum alloys, copper and other materials as dictated by design optimization. 
     A cooling element  20  may be utilized in any embodiment to provide cooling over the heat sink. In the various form factors, the pathway of air is such that air is either drawn from the front of the fixture and exhausted out the back or drawn in from the back and expelled through the front. Either configuration separates the inflow air and the outflow air which carries excess heat energy away from the LED arrays and power supply assembly. In some embodiments a shroud  30  may be present to direct airflow over the heat sink. Passive cooling or other types of active cooling may be used in any embodiment of the LED PAR. For example, passive cooling can be, but is not limited to, a heat sink with a predefined shape. 
     The power supply is designed for compatibility with legacy lighting control equipment. Legacy dimming methods designed for conventional bulbs use various techniques to delay the application of power during every half cycle of mains power as shown in  FIG. 19 . Increasing the delay reduces light output as the RMS power through the filament is reduced. Controlling switching devices, such as a Triac, SCR or IGBT facilitate this delay. 
     A power supply,  FIG. 20  in accordance with one embodiment, delivers a constant current source to the LED elements. This current level is dependent on the time during the half cycle of mains power that is applied to the system. This time, or conduction time, is detected and converted by a dim detection and level control circuit  90  to replicate the dimming behavior of a conventional bulb. For example, in one embodiment, the LED PAR utilizes a Texas Instruments LM3445 or LM3450 driver integrated circuit, a Fairchild FL7730, an ON Semiconductor NCL30000, a Power Integrations LinkSwitch-PH device, a Maxim MAX16841 or any suitable commercially available off-line triac dimmable driver integrated circuit. An embodiment uses a microcontroller for detection and level control. The circuit design embodies state of the art technology and specific components references herein are not a limitation to any embodiment of the design. 
     The power supply is an isolated or non-isolated switching mode buck regulator  95  delivering constant, regulated current. The switching device is a MOSFET capable of handling the required current and drain to source voltages with adequate safety margins and decorated design. In some embodiments, it incorporates a suitable transformer for full isolation. In other embodiments, it is directly driven from rectified mains power. The design has necessary components to provide enough power and to provide regulated current in a step-down switch mode topology. In some embodiments, active current dividing circuitry is used to balance the current delivered to the LED arrays  28  when multiple LED arrays are used. 
     The support circuitry accomplishes EMI noise filtering  55  and dampens filter ringing  60  at all applicable operational levels. The noise filter  55  is constructed of passive components providing noise suppression to meet applicable regulatory standards. Components are placed in the main power input lines, after the voltage is rectified. The dampening mechanisms  60 ,  75  for this filter embody both active elements and passive elements optimized to minimize losses. All filters are of either single or multiple pole design as required using differential or common mode inductors, RC snubbers and active devices. 
     Another feature of the present invention is bleeder circuitry,  80  and  65 , that achieves operational compatibility with current equipment design for conventional bulbs. It serves to keep the current through the equipment&#39;s control device from falling below its minimum level. This ensures flicker-free operation at any dimming level. The bleeder circuit is active  80  or passive  65  and placed at a range of points in the circuit to achieve optimum results. 
     The assembly and overall power supply design  32  is self contained, modular, and replaceable. It contains all the circuit elements that the LED arrays and cooling elements require to operate as expected. In some embodiments an enclosure  14  protects the components and allows proper ventilation to the power dissipating parts. The assembly can allow for a field replacement of the power supply as a distinct assembly. This assembly will connect to the LED arrays  28  using an interface connector  34 . In this fashion the end user can remove and replace the power supply without disassembling other parts of the LED PAR. 
     Monitoring services data is collected  84  and the information is transmitted via antenna  82  over open license radio spectrums. The invention has a suitable radio frequency transceiver  83 . At regular intervals, a microcrontroller-based supervisory circuit uses broadcasts collected data at power levels within FCC compliance. 
     The light is emitted from commercially available LEDs in an array of elements  28  referred to as Chip on Board or COB systems. Embodiments include a singular element or multiple elements arranged in a pattern that accommodates other design features or packaging requirements. Light output, color temperature and the general quality of the light dictate the choice and number of elements in any suitable design. 
     Light pattern is controlled using optical elements  18  which include reflectors, diffusers, collimators, and lenses of any variety or any custom combination thereof. Off the shelf parts are used to accomplish optical performance in some embodiments. In other embodiments, optical performance is achieved with custom designed and manufactured parts (e.g.  18  as shown in  FIG. 10 ). A broad range of variations in the invention will produce light patterns similar to standard light beam spreads, for example, of very narrow, narrow, medium flood and wide flood. 
     The construction details of the PAR LED include an embodiment of a multi-piece assembly or of any singular pieces that perform the same function as assembling separable parts. Any part or assembly may be a single piece that is cast, milled, forged, stamped or produced with a suitable a manufacturing method. It is produced as an assembly of multiple parts that may also milled, forged, stamped or produced with a suitable manufacturing method. 
     The advantages of the invention include, without limitation, the ability to replace widely manufactured conventional bulbs intended for a wide range of lighting applications. Reductions in energy use and far longer service lifetimes over the conventional bulbs are benefits of the LED PAR. Additional benefits include better light control and reducing or eliminating damage to filter gels used. A general design feature of all embodiments of the LED PAR is such that fixtures into which it is installed require minimal modification, alteration or additional parts for full functionality. 
       FIGS. 21-25  are block diagrams of example embodiments of power supply schematics. These power supply schematics may be implemented in the power supply system shown in  FIG. 20 . 
       FIG. 21  illustrates an example constant current power supply. As shown in  FIG. 21 , a constant current is delivered to the LED module from an off-line switch mode buck converter. The controller sets the LED current level accord to the conduction angle, or ‘on-time’ of the power switching device in the dimmer. 
       FIG. 22  illustrates an example EMI input filter. As shown in  FIG. 22 , the EMI input filter suppresses conducted electromagnetic noise, both common mode and differential, to acceptable levels for compliance with FCC Part 15 as a Class A device. There are two ‘LC’ filters in series and a ‘RC’ network to reduce ringing. 
       FIG. 23  illustrates an example multi-LED current divider. As shown in  FIG. 23 , current through multiple LED elements is balanced with current mirrors that include a transistor-diode network providing failsafe against an open LED condition; the present figure is a two LED embodiment. 
       FIG. 24  illustrates an example fan power supply with bleeder circuit. As shown in  FIG. 24 , power is delivered to the fan through a linear regulator comprised of a precision diode with feedback. At high mains voltage levels in the AC cycle, the circuit is disabled to reduce dissipation in the pass transistor 
       FIG. 25  illustrates an example thermal cutoff. As shown in  FIG. 25 , a thermal cutoff utilizes a voltage detector and thermistor to monitor PCB temperature and disable the buck converter if the temperature exceeds operational limits. 
     The above detailed description does not limit the LED PAR invention in scope of use, components used or any design element thereof. The embodiments do not limit this invention in the manner in which it is manufactured, assembled or produced. There is no limitation implied in specific components used in the electronic circuit as described. It should not be construed to be limited in any way as to its use in any compatible lighting fixture.