Abstract:
A lighting assembly including an elongated mounting component with two elongated and angled mounting surfaces, two or more LED-based printed circuit board having a plurality of LEDs on one surface and circuitry on a second surface. The printed circuit boards are fastened to the mounting surfaces, by a plurality of longitudinally-spaced nonconductive fasteners, substantially parallel but elevated above the mounting surfaces. The lighting assembly is configured to be mountable to extend within existing light fixtures such that the LEDs are positioned to provide a light pattern similar to the illumination pattern previously produced by the original fixture.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 13/372,297, filed Feb. 13, 2012 now abandoned, which claims priority to U.S. Provisional Patent Application No. 61/442,035, filed on Feb. 11, 2011, the disclosures of which are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates generally to the field of illumination. More specifically, the invention relates to the field of providing lighting using light emitting diodes to replace more conventional lighting systems. 
     2. Description of the Related Art 
     There are many devices used to retrofit conventional lighting fixtures, such as fluorescent lighting fixtures. For example,  FIG. 1  depicts a conventional fluorescent lamp assembly  100  that exists in numerous buildings. The lamp assembly  100  includes a housing  102  and two parallel fluorescent lamp bulbs  104 . Also included in the housing  102  is a rectangular protruding ballast cover  106 . The cover  106  (which is removable) includes not only the ballast, but also the associated electronics equipment. 
       FIG. 2  shows another conventional fluorescent lamp arrangement  200  commonly found in buildings and other structures. The lamp arrangement  200  includes a housing  202  that contains four fluorescent bulbs  204 . There is also a centrally located rectangular metal cover  206 , which houses the ballast equipment and associated electronics. 
     These lamp assemblies may be updated in a variety of fashions, but are generally retrofit using non-fluorescent bulbs, such as bulbs having a similar size and shape of a fluorescent bulb. For example, a conventional lamp assembly may be retrofit by replacing a fluorescent tube with an LED-based tube of similar shape and size. However, although such a retrofit removes the drawbacks associated with the fluorescent tube, it does little to provide additional advantages or benefits. 
     These and other problems exist with respect to conventional lighting fixture retrofitting systems and procedures. 
     SUMMARY 
     A system and method for retrofitting conventional lighting fixtures, such as retrofitting lighting fixtures using LED illumination systems that maximize the benefits of LEDs, is described. In some embodiments, the system includes a mount, or mounting component, and a printed circuit board that includes multiple light emitting diodes (LEDs). 
     In some embodiments, the mount includes two or more angled faces in which printed circuit boards having multiple LEDs are attached, in order to provide a desired spread of illumination below a lighting fixture, among other benefits. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Illustrative embodiments of the present invention are described in detail below with reference to the attached drawing figures, which are incorporated by reference herein and wherein: 
         FIG. 1  is a view of a conventional fluorescent lighting fixture which can be subjected to the systems and methods of the disclosed embodiments; 
         FIG. 2  is a view of another conventional lighting fixture which may be subjected to the systems and methods of the disclosed embodiments; 
         FIG. 3A  is a perspective view of an embodiment of a retrofit LED assembly which may be used to convert a fluorescent fixture into an LED lamp; 
         FIG. 3B  is an end view of the assembly shown in  FIG. 3A ; 
         FIG. 3C  is an underside view of the assembly shown in  FIG. 3A ; 
         FIGS. 4A-C  are three alternative schematic arrangements used to power the LED lamps; 
         FIG. 5A  shows a side view of a connector block used to electrically and physically connect two PCBs together at a joint; 
         FIG. 5B  shows a back side view of the connector block shown in  FIG. 5A ; 
         FIG. 5C  shows a top view of an alternative connector block wherein the traces are included on the top of the block; 
         FIG. 5D  shows a view of a connector block from above in place between two PCBs; 
         FIG. 5E  shows a side view of a connector block installed between two PCBs; 
         FIG. 5F  shows a view of the connector block installed between two PCBs from below; 
         FIG. 5G  shows the ends of two PCBs as they appear before the connector block is installed; 
         FIG. 6  is a perspective view of the fluorescent lamp housing shown in  FIG. 1  after it has been subjected to the processes and systems of the disclosed embodiments, and; 
         FIG. 7  is a perspective view of the fluorescent lamp housing shown in  FIG. 2  after it has been subjected to the processes and systems of the disclosed embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     As described herein, in some embodiments, a system and method for incorporating LEDs into existing lighting environments is described. 
       FIGS. 3A-C  show a lighting assembly  300  that is configured to be mounted into numerous existing fluorescent fixtures for retrofitting purposes. Looking first at  FIG. 3A , we see a mounting component or mount  302 , which may be constructed of sheet metal. Mount  302  is used to support a first elongated printed circuit board (PCB)  304  of LEDs and a second elongated PCB  306  of LEDs. As described in more detail herein, the boards  304  and  306  may be constructed of multiple smaller LED boards that are connected together using PCB connector blocks. Thus, each of the two elongated boards  304  and  306  are, in some embodiments, formed of smaller boards. 
     The two elongated boards  304  and  306  are mounted atop the mount  302  using non-conductive PCB spacer fasteners  308 . The spacer fasteners  308  support each of the elongated PCB boards  304  and  306  at a slight distance above upper angled surfaces of the mount  302 . The fasteners  308  may be constructed using flame-retardant nylon. The structural details regarding these fasteners  308  are discussed herein. 
     Multiple LEDs  310  are included on each of the boards  304  and  306 . For example, in some embodiments, the selected LEDs are six ohm, 3.5 volt, 20 milliamp, 92% efficient, LEDs, with suitable LED dies. These dies may be commercially available. 
       FIG. 3A  also depicts certain configurations, or groupings, of multiple LEDs  310  on boards  304  and  306 . For example, in some embodiments, the boards  304 ,  306  may include a first group of LEDs  310   a  as well as a second group of LEDs  310   b . In some cases, the LEDs are broken into groups of six LEDs for a variety of reasons, such as for separate operational purposes. One skilled in the art will recognize, however, that various different sizes of groups could be used to accomplish different purposes. It should also be understood that although only two groups ( 310   a  and  310   b ) have been identified in  FIG. 3A , the rest of the remaining LEDs could also be broken out in to a variety of groupings to accomplish dimming, directional lighting, contrasted lighting arrangements or patterns and/or other desired light-controlling objectives. 
     Referring again to  FIG. 3A , the first board  304  and second board  306  extend from a first end  314  to a second end  316  of the mount  302 . At the first end  314 , the mount  302  includes a pair of power supply terminals  312  shown at both ends of each of boards  304  and  306 . These terminals  312  may be electrically connected to a variety of power sources, such as AC primary power, emergency AC backup power, and/or DC battery backup power, using wires or other conductor pair arrangements. The LEDs  300 , including LEDs groups  310   a  and  310   b , may be controlled using circuitry existing on the back of the boards  304  and  306 . Further details regarding various circuitry arrangements are described herein. 
     As described herein, in some embodiments, the mount  302  is configured to include two or more angled faces onto which the board  304  and  306  are attached.  FIG. 3B  depicts a cross-sectional view of the mount  302 . The mount  302  includes an angled face  318  on a first side, and another angled face  320  on the opposite side. Above face  318 , a leveled off face  322  exists at an angle α relative to horizontal. In some embodiments, angle α falls within the range of 15 degrees, plus or minus 10 degrees. In some embodiments, angle α falls within the range of 15 degrees, plus or minus 5 degrees. In some embodiments, angle α falls within the range of 15 degrees, plus or minus 3 degrees. In some embodiments, angle α falls within the range of 15 degrees, plus or minus 1.5 degrees. In some embodiments, such as those depicted in  FIG. 3B , angle α is about or approximately 15 degrees. Having such ranges, the mount  302  provides a desired spread of illumination emitted by the LEDs based on an average ceiling height. Therefore, different angles may be more desirable, depending on ceiling height and/or other parameters. 
     The opposite side of the mount  302  is symmetrical in that immediately above face  320  is a face  324  that is also at angle α relative to horizontal. At the bottom of mount  302  there are two opposing flanges  326  and  328  which extend out horizontally and rest atop the inside housing of a fixture being retrofitted. The mount  302  may be fastened inside a housing of the fixture by self-tapping fasteners (not shown) that are screwed through holes  330  and  332  bored through the flanges  326  and  328 , respectively. 
     The boards  304  and  306  each rest atop a platform portion  334  provided on each of fasteners  308 . These platform portions  334  are on top of a body portion  336  of each fastener  308 . The top portions  333  of each fastener can be forced through holes formed in the end of each sub-board (e.g., boards  354 ,  356 ,  358 , and  360  of  FIG. 3A ). On the bottom of each fastener  308  is an insertable snap-lock tab  338 , which may be inserted through a hole made through the angled faces  322  and  324 . This secures each fastener  308  to the top of the mount  302  in an upright position as shown. 
     As described herein, the angle α of faces  322  and  324  of the mount  302  facilitates a desired illumination spread when the assembly is mounted into an existing fixture. In some embodiments, the assembly  300  may facilitate a real-time or current adjustment of the faces  322  and  324  with respect to one another. The mount  302  may include a pivot component  340  configured to enable an adjustment of angle α during a retrofit of a fixture. That is, in some embodiments, the mount  302  may be adjustable before, during, and/or after a retrofit into an existing fixture. 
       FIG. 3C  shows an underside view of the mount  302 . In this view an undersurface  344  exposes three devices—an emergency battery  348 , an emergency power supply  350 , and a main power supply  352 . The devices ( 348 ,  350 , and  352 ) can be fastened to the underside of the mount  302  using adhesives, fasteners, and/or other attachment components. Main power supply  352 , such as a universal AC input, is used to tap into an existing power source in a building or other structure. Under normal operation, this device receives power from a power source in the building, and then supplies power to the LEDs  310 —so long as there is power to the building. In cases when the primary power to the building is lost, and assuming that the building is the sort that has an emergency backup AC power source, emergency backup power supply  350  may be used to supply AC power to the LEDs, such as to a reduced number of the LEDs  310 . In cases where all AC sources are not available, battery  348  and associated DC power supply  350  will be brought into action and used to illuminate a reduced number of operational LEDs on the mount  302 . 
     Depending on the circumstances, there are numerous ways that the emergency lighting could be accomplished. In some embodiments, all of the LEDs  310  are active when the device is receiving power from the primary AC source (via power supply  352 ). Alternatively, a small number of the LEDs  310  will not be illuminated when the device is receiving the primary source of AC from the building. That is, only  310 A and  310 B could be configured to not illuminate when the primary source of AC power is available from the building. This smaller “emergency” group of LEDs would only illuminate when the primary source of AC is not available. For example, 80% of LEDs may be included in the primary group, and 20% may be included in the backup group. In this example, the 20% of the LEDs are not used in normal operation, and are only illuminated when there is a total power failure. 
     In some embodiments, all of the LEDs  310  could be used in normal operation. Then, upon a total AC power failure, emergency power supply  350  and possibly battery  348  could be used to activate the limited emergency group (some of the same LEDs used during normal operation) for the emergency purposes. For example, both of groups  310 A and  310 B (twelve LEDs total) may be the LEDs illuminated during the emergency. 
     As described herein, a variety of circuitry arrangements may be utilized when illuminating LEDs on the boards  304  and  306  of the retrofit lighting assembly  300 .  FIGS. 4A-C  show various embodiments for the circuitry used to deliver and control power to the LEDs. This circuitry would be included on the reverse side of the PCBs. 
     Referring to  FIG. 4A , multiple LED strings are placed into parallel arrays, each string including four LEDs  402   a  and having a resistor  404 A. The use of the resistor  404 A provides a constant brightness arrangement in which the overall device will not be dimmable. Additionally, this arrangement may not support the selecting illumination of different groups of LEDs. Thus, although suitable for operation,  FIG. 4A  depicts a basic, cost-effective circuitry arrangement. 
       FIG. 4B  depicts a six LED arrangement  402 B, which is supported by a linear driver  404   b . These devices allow for the delivery of the necessary current for driving LEDs  402   b , and may be more efficient with respect to the arrangement shown in  FIG. 4A . 
       FIG. 4C  depicts a circuitry arrangement that facilitates the dimming of the lighting assembly. To do this, it includes a communications microprocessor  404   c  and a smart multichannel linear LED driver  406   c . The power administered through driver  406   c  is controlled using the communications microprocessor  404   c , and may be fully networked. 
     This arrangement includes a primary side  401   c , and an emergency side  403   c . For the primary side  401   c , the communications processor  404   c  is used to control a smart multichannel linear driver  406   c  to operate the primary group of LEDs  310 . This primary group may include of all of the LEDs  310 , or only the LEDs  310  not included in the smaller groups  310   a  and  310   b . Regardless, the linear driver  406   c  receives a communicated signal from communications processor  404   c  to turn the primary set of LEDs on or off. These LEDs would be “on” when the primary source of AC power is available. The communications processor  404   c  may also communicate with a network gateway  414   c , which may be patched into a network  412   c  (e.g., the internet or an intranet arrangement). Thus, the LEDs  310  are able to be turned on or off via a personal computer, wireless device or any other networkable device. 
     On the emergency side  403   c  of the system, lighting of a reduced number of LEDs will occur in the event that the primary source of AC power in the building is down, and the AC emergency backup system or the DC battery backup are utilized. When these secondary sources of power are utilized, communications processor  408   c  activates driver circuit  410   c  to drive the emergency group or groups of LEDs (e.g.  310   a  and  310   b ). Since communications processor  408   c  is accessible through gateway  414   c , it is totally networkable. Thus, when desired, LED groups  310   a  and  310   b  can be independently activated (or not) over the network  412 C. 
     In some embodiments, groups  310   a  and  310   b  are not also included in the primary circuit  401   c . The two sides  401   c  and  403   c  are completely independent, and the LED groups  310   a  and  310   b  will only be activated in the event of an emergency. In an alternative embodiment, groups  310   a  and  310   b  are also included on the primary side  401 C of the circuit, and may be illuminated not only in backup situations, but also when AC primary power is available. 
     In some embodiments, the circuitry arrangement may be configured to provide independent control of the left and right strings of LEDs or combination of LED strings, allowing one to be turned off while one remains illuminated, or to have both LED strings “ON” or “OFF”. Incorporating a dimmer-switch board, the circuitry arrangement facilitates such a bi-level dimming capability of each elongated LED board and provides a light output at the levels of 0%, 50%, and/or 100%. When power is cycled to the elongated LED board, within a short amount of time this change may be detected by a power loss detection circuit on the dimmer-switch board, which sees this change as a signal to alternate the dimming state of the elongated LED board from both LED strings “ON” or both strings “OFF” to one string “ON” and one string “OFF” (delivering 50% light output). When power is turned off for longer than a predetermined length of time, the dimmer-switch board will reset its dimming state such that 100% of the LED strings will be on the next time the elongated LED board is powered on. Because the individual elongated LED boards can be controlled on a per strip basis, the number of dimming steps can be expanded per application. 
     In some embodiments, the circuitry arrangement may be configured to facilitate switching the reception of power from the electric grid to a battery backup during peak electrical usage hours, thereby removing the electrical load that the elongated LED board would typically put onto the electric grid. The system will be able to switch back to being powered from the electrical grid after peak usage hours. The battery backup will automatically charge during predetermined low usage hours and will also run on a staggered or random charging schedule during these low usage hours to avoid all of the lighting systems trying to charge simultaneously, which may place an undesirable heavy load onto the electric grid. The battery backed up elongated LED boards may also switch back onto the electrical grid on a staggered or random schedule to further avoid putting an undesirable heavy load onto the electric grid. The nighttime energy harvesting system may be able to automatically compensate for daylight savings and other time change occurrences via an onboard RTC (real time clock) chip that will keep track of the time and date, or by a manual adjustment via an external control mechanism, among other things. The nighttime energy harvesting system will also have an emergency power save feature that will switch the elongated LED board back onto the electrical grid regardless of the time of day if the battery backup reaches a certain percentage below “fully charged”. This feature thereby ensures that, in case of emergency, the elongated LED board will still have a reserve of power to energize itself for a period of time. 
     As described herein, the elongated boards  304  and  306  may be formed of multiple PC boards.  FIGS. 5A-G  depict various configurations in which smaller PC boards (e.g., boards  354 ,  356 ,  358 , and  360 ) may be connected together to comprise two elongated boards  304  and  306 . 
     In some embodiments, in order to connect two smaller boards to one another, a connector board  502  is used to both physically join the two abutting ends, such as ends  504  and  506  of boards  354  and  356 , respectively. On each of ends  504  and  506 , pin receiving holes  508  and  512  are shown associated with traces  510  and  514 . Traces  510  and  514  extend to the end of the boards  504  and  506 . Alternatively, traces  510  and  514  may not be required, depending on the extent of the traces (e.g., traces  516 ) on the connector board  502 . For example, when traces  516  on the connector board  502  are long enough to reach the pin receiving holes  508  and  512  on boards  354  and  356 , the traces  510  and  514  will not be required. 
     In  FIG. 5A , the connector board  502  includes a base portion  522  and a female receptacle  518 . Female receptacle  518  is a well-known device, which includes pins and receives a plug connector, such as plug connector  530  shown in  FIG. 5E . 
       FIG. 5B  depicts an engagement side  522  of bottom portion  520  of the connector board  502 . On the engagement side  522 , each of pin receiving holes  508  and  512  are interconnected by a plurality of parallel traces  516 . These traces  516  will be used to electrically and signally connect the blurred ends to each other, as shown in more detail in  FIG. 5E . 
       FIG. 5E  depicts an interconnect board  520  that has been used to punch together two board ends  504  and  506  using pins  536 . Pins  536  are used to conduct electrical power, transmit communications signals, and physically secure the boards  354  and  356  to each other such that the connection of all the smaller boards comprises the two elongated boards  304  and  306 . As depicted, the female receptacle  518  extends downward after the interconnector board  520  has been pinned to each PCB end. Thus, a plug connector  530  can be inserted and secured in the receptacle  518  to make the necessary electrical connections. 
       FIG. 5F  depicts the interconnecting member  502  installed on the underside of board ends  354  and  356 , showing the female receptacle  518  and the connecting pin heads  537 . In  FIG. 5F , the plug  530  has not yet been inserted. 
       FIG. 5C  depicts an alternative tracing arrangement for the connector  502 . In  FIG. 5C , the traces  550  are on the same side of the connector board as the female receptacle  518 . These traces are angled outward to meet up with the pin heads  537  upon installation. 
     Thus, in some embodiments, the small PC boards are connected with a variety of mechanisms to fix the boards to one another, to transfer electric current to one another, to communicate with one another, and so on. For example, utilizing the connections described in  FIGS. 5A-5F , two connected PC boards may rotate with respect to one another, among other things. 
     As described herein, the mount  302  and attached PC boards  304  and  306  are configured to be installed into existing lighting fixtures, such as fluorescent tube lighting fixtures, in order to retrofit the lighting fixtures with an LED-based illumination system that provides desirable illumination patterns, among other benefits.  FIG. 6  shows an installation of the retrofit device on mount  302  in an existing fluorescent housing. 
       FIG. 7  shows a dual-installation where two retrofit devices are used to convert a four-bulb fluorescent light arrangement. 
     In some embodiments, in order to retrofit the lighting assembly  300  into an existing housing, such as fluorescent lamp housings  100  and  200 , the following steps may be performed. 
     After shutting off power to the unit, the existing ballast equipment and the cover (e.g., cover  106 ) are removed, along with any remaining bulbs. However, in some cases ballast removal may not be necessary because of where the mount  302  is to be secured. 
     With respect to the assembly of  FIG. 6 , after the ballast and cover have been stripped from the unit, a single retrofit lighting assembly  300  is fastened into the space formerly occupied by the ballast equipment, and fasteners (e.g., screws, not shown) can be secured into the back of the housing through attachment holes  330 . 
     With respect to the assembly of  FIG. 7 , since the ballast arrangement and cover  206  are located in the center of the housing and do not have to be removed, two separate duplicate versions  702  of the lighting assembly  300  can be fixed into the back of the housing as shown. 
     Once the lighting assemblies  300  have been installed, electrical connections are made. For example, connections are made from the building primary AC source and building emergency power supplies into power sources  352  and  350 , respectively, and from each of the power sources  350 ,  352 , and battery  348  into the PCB circuitry. Also, battery  348  may be electrically connected to the primary AC source so that it can remain charged. Once installed and electrically connected, the new retrofit devices ( 600  or  700 ) are ready for operation. 
     Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of the present invention. Embodiments of the present invention have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develop alternative means of implementing the aforementioned improvements without departing from the scope of the present invention. 
     It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims. Not all steps listed in the various figures need be carried out in the specific order described.