Abstract:
A light emitting apparatus and method of manufacturing thereof are disclosed. The light emitting apparatus includes a plurality of printed circuit boards connected to one another, a light emitting element disposed on and electrically connected to each printed circuit board, and at least one connector disposed between the printed circuit boards. The method of manufacturing the light emitting apparatus includes disposing a light emitting element on a plurality of printed circuit boards, arranging planar surfaces of the plurality of printed circuit boards substantially opposite, and connecting the plurality of printed circuit boards to one another.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This applications claims benefit of U.S. Provisional Applications Ser. No. 60/756,577 filed on Jan. 6, 2006, entitled “Method for creating a 360 degree viewable pixelated LED tube or rope” in the names of Matthew Ward, Jeremy Hochman, Nils Thorjussen, and Chris Varrin. 

   BACKGROUND OF INVENTION 
   1. Field of the Invention 
   Embodiments disclosed herein generally relate to light emitting apparatuses. Specifically, selected embodiments relate to an improved light emitting apparatus for use in various industries. 
   2. Background Art 
   Currently, the market for light emitting diode (“LED”) technology is growing at an astonishing rate for use in various industries, such as in the entertainment, advertising, and architecture industries. Within this LED technology market are linear LED products, such as LED tubes and LED ropes. These linear LED products have been large contributors to the market&#39;s popularity because of their versatility in usage. For example, the linear LED products may be used for neon simulators, decorative lightings, in addition to low resolution video displays. 
   Because of their high demand, LED ropes and LED tubes are available from several manufacturers. The LED ropes are generally available, though, in a form that is only viewable from one side. The side of the LED ropes that is not viewable contains wires and components that blocks light from the LEDs within the rope from being seen. Similarly, the LED tubes are generally in a form that prevents a 360 degree viewable angle. These LED tubes have an extruded or fabricated metal or plastic component to cover at least a portion of the back of the tubes. This back component of the LED tubes is usually used as a structural support or a base for the LEDs within the tubes. U.S. Pat. Nos. 6,676,284 and 7,118,248, issued to Willson, and U.S. Pat. No. 6,592,238, issued to Cleaver et al., disclose examples of such LED tube systems with a limited viewable angle. 
   Referring to  FIG. 1 , an example of a LED tube  101  with a linear array of LEDs  105  is shown. LED tube  101  includes an elongate diffuser  103 , made of rigid, translucent diffusing plastics material, mounted onto base  109 . LEDs  105  are mounted on and electrically connected to a printed circuit board  107  (“PCB”), in which PCB  107  is mounted on and supported by base  109 . Commonly, linear array of LEDs  105  are in close proximity to one another, individually controlled, and have a repeating pattern of colors of red, blue, and green. When in operation and illuminated, light from linear array of LEDs  105  is diffused through diffuser  103  such that, by a distant viewer, the light appears to be emanating from a continuous light source, instead of from individual point light sources of LEDs  105 . 
   Referring now to  FIG. 2 , another example of a LED tube  201  is shown. Similar to LED tube  101  in  FIG. 1 , LED tube  201  comprises a linear array of LEDs  205  mounted on and electrically connected to a PCB  207 , in which PCB  207  is mounted on and supported by base  209 . Additionally, LED tube  201  has two diffusers (an outer diffuser  203  and an inner diffuser  213 ) and a reflector  211 . Reflector  211  may be used to maximize the light output from LEDs  205 , such as reducing the light loss to PCB  207 . 
   As shown with  FIGS. 1 and 2 , the LED tubes make use of PCB-mounted LEDs with the LEDs arranged in an array or line within the tubes. In these arrangements, the viewable angle of light surrounding the LED tubes is limited by the PCBs and bases on which the LEDs are mounted. In  FIG. 1 , the viewable angle of LED tube  101  is limited to about 190 degrees. In  FIG. 2 , the viewable angle of LED tube  201  is limited to about 270 degrees. The use of the diffusers may increase the viewable angles of the LED tubes, but a substantial portion of the LED tubes is blocked by internal and external components of the tubes. With these components blocking light emitting from the LED tubes, the viewable angle of the light from the LED tubes will always be limited. 
   In response to these common limited viewable angle LED tubes, many manufacturers have created “360 degree” viewable angle linear LED products. These linear LED products, though, still require wires or connectors to pass the data and power signals from one light source to the next. The wires and connectors may then produce a shadow, dark area, or discontinuity on the outside diffuser of the linear LED product. Thus, the viewable angle of linear LED products is still limited from the full 360 degrees. 
   Accordingly, there exists a need for a linear LED product that minimizes any shadows or discontinuities by the internal connections, wires, or support structures to allow the LED product to be fully viewable from all 360 degrees surrounding the product. 
   SUMMARY OF INVENTION 
   In one aspect, embodiments disclosed herein relate to a light emitting apparatus. The light emitting apparatus includes a plurality of printed circuit boards electrically connected to one another, a light emitting element disposed on and electrically connected to each of the plurality of printed circuit boards, and at least one connector disposed between the plurality of printed circuit boards. 
   In another aspect, embodiments disclosed herein relate to another light emitting apparatus. The light emitting apparatus includes a first printed circuit board having a planar surface, a second printed circuit board having a planar surface, at least one light emitting element disposed on the first and second printed circuit boards, and at least one connector disposed between the first and second printed circuit boards. The planar surface of the second printed circuit board is arranged substantially opposite to the planar surface of the first printed circuit board, and the first printed circuit board is electrically connected to the second printed circuit board. 
   Further, in another aspect, embodiments disclosed herein relate to a method for manufacturing a light emitting apparatus. The method includes disposing a light emitting element on a plurality of printed circuit boards, arranging the plurality of printed circuit boards such that planar surfaces of the plurality of printed circuit boards are substantially opposite, and electrically connecting the plurality of printed circuit boards to one another. 
   Other aspects and advantages of the invention will be apparent from the following description and the appended claims. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  is a cross-sectional view of a prior art LED tube. 
       FIG. 2  is a cross-sectional view of another prior art LED tube. 
       FIG. 3  is a perspective view of a module of a light emitting apparatus in accordance with embodiments disclosed herein. 
       FIGS. 4A-C  are perspective views of a module of a light emitting apparatus in accordance with embodiments disclosed herein. 
       FIG. 5  is a perspective view of a light emitting apparatus in accordance with embodiments disclosed herein. 
       FIGS. 6A-D  are perspective views of a light emitting apparatus in accordance with embodiments disclosed herein. 
       FIGS. 7A-B  are perspective views of a light emitting apparatus in accordance with embodiments disclosed herein. 
   

   DETAILED DESCRIPTION 
   In one aspect, embodiments disclosed herein relate to an improved light emitting apparatus with a 360 degree viewable angle. In another aspect, embodiments disclosed herein relate to a light emitting apparatus having a plurality of PCBs, in which a light emitting element is disposed on each of the plurality of PCBs. In another aspect, embodiments disclosed herein relate to a light emitting apparatus having a plurality of PCBs, in which planar surfaces of the PCBs are substantially opposite of one another. 
   Referring now to  FIG. 3 , a perspective view of a module  301  of a light emitting apparatus in accordance with embodiments disclosed herein is shown. Module  301  includes a light emitting element  305  disposed on a PCB  307 . As shown, PCB  307  may include planar surfaces  309  (e.g., planar surfaces  309  may include a top surface and a bottom surface of PCB  307 ). Light emitting element  305  may be disposed on one of, or both, planar surfaces  309 . Light emitting element  305  is electrically connected to PCB  307  to enable signals from PCB  307  to control (e.g., turn on and off) light emitting element  305 . An optical material  303  may then encompass or enclose PCB  307  and light emitting element  305  of module  301 . In this embodiment, optical material  303  is supported against outer edges of PCB  307  to encompass module  301 . Further, connectors  321  are disposed on and electrically connected to PCB  307 . Connectors  321  may carry all necessary data and power signals for controlling module  301 , in which the data and power signals may be supplied to light emitting element  305  through PCB  307 . As shown, connectors  321  may be circular in cross-section with a minimum sized diameter to impede as little amount of light as possible emitting from light emitting element  305  and reaching optical material  303 . 
   Preferably, the optical material comprises a diffusive material to diffuse light emitted from light emitting element. However, those having ordinary skill in the art will appreciate that the invention is not so limited, and the optical material may comprise a transparent material, a translucent material, a colored material, a refractive material, a reflective material, a catadioptric material, in addition to any other materials known in the art. Further, those having ordinary skill in the art will appreciate that the invention is not limited to any particular shape. Thus, the optical material may comprise a spherical shape, an aspherical shape, a convex shape, a concave shape, a conical shape, an elliptical shape, a hyperbolic shape, a parabolic shape, a lenticular shape, in addition to any other shapes known in the art. Furthermore, the optical material may comprise any combination of the previously suggested materials and shapes. For example, the optical material may comprise a conical shape with one portion a diffusive material and another portion a colored material, or the optical material may comprise a portion that is both a diffusive and colored material that is of a spherical shape. 
   Using the connectors to connect between multiple PCBs, multiple modules may be arranged in a stack or ‘column alignment’ to assemble a light emitting apparatus of the present invention. As used herein, a column alignment refers to an arrangement of the PCBs with respect to one another, in which the PCBs are positioned one above the other with the connectors disposed therebetween. Thus, the light emitting apparatus of the present invention may comprise an arrangement of alternating PCBs and connectors with an optical material encompassing the PCBs. 
   Those having ordinary skill in the art will appreciate that, although embodiments disclosed herein are only shown with one light emitting element disposed on and electrically connected to each PCB, the invention is not so limited. In other embodiments, multiple light emitting elements, such as multiple LEDs, may be disposed on each PCB. In such a case, the LEDs may emit different colors, such as red, green, and blue, as is common for a pixel comprised of LEDs. 
   Referring now to  FIGS. 4A-C , a perspective view of a module  401  of a light emitting apparatus in accordance with embodiments disclosed herein is shown. Similar to module  301  in  FIG. 3 , module  401  in  FIG. 4A  includes a light emitting element  405  disposed on and electrically connected to PCB  407  with an optical material  403  encompassing or enclosing PCB  407  and light emitting element  405 . However, in this embodiment, PCB  407  is disposed on a support structure  431  (shown in  FIG. 4B ), which may be comprised of the same or similar material as optical material  403 . Support structure  431  includes guide holes  433  to correspond with guide holes  413  of PCB  407 . Specifically, guide holes  433  of support structure  431  are approximately in the same location corresponding to guide holes  413  of PCB  407  so that when PCB  407  is disposed on support structure  431 , connectors  421  (shown in  FIG. 4C ) may pass through holes  413  and  433  without any intrusions. 
   As shown in  FIG. 4C , connector  421  may be a thin, flat blade or fastener and include a pin section  423  and a crimp section  425 . Preferably, pin section  423  is sufficient in width to provide a current flow for the transmission of the necessary data and power signals for multiple modules  401 , but remains relatively thin to impede a minimum amount of light emitting from light emitting element  405  reaching optical material  403 . Crimp section  425  may be used to retain connector  421  within hole  433  of support structure  431  and pin section  423  may be used to electrically connect multiple PCBs  407  to one another. When connected to PCBs  407 , preferably connectors  421  are oriented within holes  413 ,  433  such that pin sections  423  are aligned parallel with the light rays emitting from light emitting elements  405  to impede as little amount of light as possible emitting from light emitting elements  405  reaching optical material  403 . 
   Referring back to  FIG. 4A , module  401  may include as many as six holes  413 ,  433  within PCB  407  and support structure  431 , if not more. With six locations (e.g., A, B, C, D, +, −) of holes  413 ,  433 , locations + and − may be used for transmission of power signals, and locations A, B, C, and D may be used for transmission of data signals. For example, when connecting two modules  401 , one module may use locations A, B, +, and − of holes  413 ,  433  for transmission data and power signals, and the other module may use locations C, D, +, and − of holes  413 ,  433  for transmission of data and power signals. Therefore, some of the data and power signals supplied by connectors  421  through holes  413 ,  433  may not be utilized in one module, but may be used in another module. However, those having ordinary skill in the art will appreciate the invention is not so limited, and any number of the holes within the PCB may be used. 
   As shown, the connectors disposed between the multiple PCBs and the optical material that encompasses the PCBs may comprise a rigid material to provide structural support for the light emitting apparatus of the present invention. However, those having ordinary skill in the art will appreciate that the invention is not so limited. For example, in another embodiment, the connectors disposed between the PCBs may comprise a flexible material (e.g., metal bellows) or a spring material (e.g., rubber or metal springs) and the optical material may comprise a flexible material (e.g., thin plastic). In such an embodiment, the light emitting apparatus may then be bent in any direction, similar to that of rope, to increase the flexibility and versatility of the present invention. 
   Referring now to  FIG. 5 , a perspective view of multiple modules  501  of a light emitting apparatus  500  in accordance with embodiments disclosed herein is shown. Similar to modules  301 ,  401  described above, modules  501  include light emitting elements  505  disposed on and electrically connected to PCBs  507 . Further, in this embodiment, PCBs  507  include holes  513  for connectors  521  to pass through PCBs  507 . As shown, connectors  521  disposed between PCBs  507  may include cables or wires. In such an embodiment, insulation of the cables or wires may be pierced at the location of the holes to provide an electrical connection with the PCBs. Alternatively, instead of piercing the cables or wires, the cables or wires may be cut and electrically connected to other locations of the PCBs. Alternatively still, the cables or wires may be clamped or secured by connectors disposed on the PCBs to provide an electrical connection with the PCBs. 
   Referring now to  FIGS. 6A-D , perspective views of multiple modules  601  of a light emitting apparatus  600  in accordance with embodiments disclosed herein are shown. Light emitting elements  605  are disposed on planar surfaces  609  of PCBs  607  and electrically connected to PCBs  607  with an optical material  603  encompassing PCBs  607  and light emitting elements  605 . Connectors  621  are disposed between and electrically connected to PCBs  607 . Data and power signals to control light emitting elements  605  may be sent from a source (not shown) through an end  641  of light emitting apparatus  600  into each module  601  and PCB  607  using connectors  621 . Thus, in this embodiment, the data and power signals for all the modules of the light emitting apparatus may be sent through the connectors into each module. As such, the modules may only use the data and power signals attributed to their particular module when controlled. 
   Alternatively, instead of only sending the data and power signals from one or more of the ends of the light emitting apparatus to the modules, those having ordinary skill in the art will appreciate that the modules of the light emitting apparatus may include electrical connections to receive power and data signals from one or more sources. For example, a module of the light emitting apparatus may include an electrical connection within the optical material and the PCB to allow for power and data signals from additional sources to be supplied to specific modules of the light emitting apparatus. As such, this may enable longer and/or larger light emitting apparatuses to be created because multiple electrical connections may be used to supply data and power signals to the light emitting apparatus. 
   Further, the modules of the light emitting apparatus may be manufactured separately such that each module may be independently connected and disconnected to the light emitting apparatus. In such an embodiment, the light emitting apparatus may be modular to enable quick and easy construction of the light emitting apparatus with the separately manufactured modules. 
   In the embodiments disclosed herein, the light emitting apparatus of the present invention includes multiple PCBs. These PCBs are arranged within the light emitting apparatus such that the planar surfaces of PCBs are ‘substantially opposite’ one another. As used herein, substantially opposite refers to the arrangement of the PCBs with respect to one another, in which the PCBs are arranged within the light emitting apparatus such that planar surfaces of the PCBs substantially face on another. Thus, when the planar surfaces of PCBs are substantially opposite, light emitting from a light emitting element disposed on one planar surface of a PCB may emit light onto another planar surface of a PCB. For example, in  FIG. 6A , the planar surfaces  609 A of PCBs  607  with light emitting elements  605  are directly opposite, parallel to, and facing planar surfaces  609 B of PCBs  607  without light emitting elements  605 . However, in another embodiment, when the planar surfaces of the PCBs are substantially opposite to one another, the orientation angles of the PCBs may be such that the planar surfaces of the PCBs are not parallel to one another. In such an embodiment, one planar surface of a PCB may be oriented 45 degrees in one direction, while a planar surface of the next PCB may be oriented 45 degrees in the other direction. Those having ordinary skill in the art will appreciate that other orientations and arrangements with PCBs substantially opposite of one another also exist and are included within the scope of the present invention. 
   Further, in the embodiments disclosed herein, the light emitting apparatus may include sensors disposed within the modules and electrically connected to the PCBs. The sensors may include image sensors (e.g., charge-coupled devices (CCD) or complementary metal-oxide-semiconductor (CMOS) sensors), infra-red sensors, sound sensors (e.g., microphone), in addition to any other sensors known in the art. The sensors may, for example, enable the light emitting apparatus to detect multiple working conditions of the apparatus and assist in determining if the light emitting apparatus is fully functional. Further, the sensors may enable the light emitting apparatus to detect multiple environmental conditions outside of the light emitting apparatus to determine, for example, if spectators are nearby or if other surrounding displays and apparatuses are in use. With detection of environmental conditions, the sensors may enable the light emitting apparatus to interact with its environment, such as illuminating in the presence of spectators. 
   With the inclusion of sensors within the light emitting apparatus, it may be beneficial to include a lens, prism, or any other optical device known in the art within the modules to assist in directing light within the modules. For example, if both a sensor and a light emitting element are included within a module, it is possible that neither the light emitting element nor the sensor is located within the center of the module. In such a embodiment, the light emitted from the light emitting element may illuminate one side of the module more than another side of the module. To prevent such a problem, an optical device may be included within the module of the light emitting apparatus to recreate a uniform distribution of light within the module. 
   Furthermore, in the embodiments disclosed herein, the light emitting apparatus may include photovoltaic components electrically connected to the PCBs. Generally, photovoltaic components convert energy from photons within light into electrical energy. With photovoltaic components, light (e.g., sunlight) may be converted into electrical energy to supplement at least a portion, if not all, of the power used by the light emitting apparatus. 
   Those having ordinary skill in the art will appreciate that although the modules of the present invention are shown such that each module may have two adjacent modules connected (generally an adjacent module connected above and an adjacent module connected below), the invention is not so limited. In other embodiments, a module may have more than two adjacent modules connected thereto. For example, a module of a light emitting element may have a general Y-shape to connect to three adjacent modules, or may have a general T-shape to connect to four adjacent modules. Thus, light emitting apparatuses of the present invention may have multiple branches originating from modules configured to connect to more than two adjacent modules. 
   Additionally, as shown above, the PCBs and the light emitting apparatus of the present invention include a generally circular cross-section. However, those having ordinary skill in the art will appreciate that the invention is not so limited. In other embodiments, the cross-section of the PCBs and/or the light emitting apparatus may be square, triangular, oval, in addition to many other polygonal shapes known in the art. For example, in  FIGS. 7A and 7B , a light emitting apparatus  700  in accordance with embodiments disclosed herein is shown. PCBs  707  of light emitting apparatus  700  are of a polygonal (e.g., rectangular) shape, with multiple light emitting elements  705  disposed upon and electrically connected to each PCB  707 . An optical material  703  encompasses the multiple light emitting elements  705  and may allow light to emit through optical material  703 . 
   Further, as shown above, the embodiments of the light emitting apparatus have power sent to the PCBs from an outside source. However, those having ordinary skill in the art will appreciate that the invention is not so limited. In other embodiments, an electrical energy storage device may be incorporated into the light emitting apparatus such that an outside power supply may not be needed. For example, a battery may be disposed on or within an end of the light emitting apparatus for power supply. 
   Embodiments of the present invention may provide for one or more of the following advantages. In one embodiment, the present invention may provide for a light emitting apparatus that is viewable from a 360 degree angle surrounding the light emitting apparatus. In another embodiment, multiple light emitting apparatuses may be used and stacked in a system, such as an array. This system may be a two or three-dimensional array, in which two or three-dimensional video images may be created with the array of light emitting apparatuses. In another embodiment, the present invention may provide for a flexible light emitting apparatus. In such an embodiment, the bendable apparatus may or may not spring back into its original form after being bent. 
   While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.