Patent Publication Number: US-8111208-B2

Title: Front and rear removable panel for electronic displays

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is related to U.S. patent application Ser. No. 12/416,856, filed on Apr. 1, 2009, pending, titled “Incident Light Management Devices and Related Methods and Systems,” assigned to the assignee of the present application. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to displaying images, more specifically, to displaying images on display boards and billboards. 
     2. State of the Art 
     Billboards and large signs have been used for many years to convey information to passersby such as advertising, traffic messages, and the like. Traditionally these signs and billboards were only capable of delivering a single message or advertisement. This message was generally printed on strips of paper that were then adhered to the billboard. To change the message, new paper needed to be printed and adhered to the billboard. 
     More recently, display boards and billboards have become electronic using lights, light-emitting diodes (LEDs), and combinations of the two to display a visual message that could be easily adaptable to display a wide variety of messages in the form of words and images from the same sign without having to physically change the characteristics of the sign. These electronic boards can easily modify a graphic image or message to create video displays and modify the type of message or advertisement that is shown on the electronic board at regular intervals, or at targeted times depending on expected traffic near the sign, or public interest. These possible images are generally referred to herein as adaptable images. 
     While the adaptable images may be changed easily on these electronic boards, maintaining and servicing an electronic board with thousands (or even hundreds of thousands) of lights attached to the electronic boards can be problematic. Smaller removable panels, which may be tiled together, have been proposed to make this maintenance task easier. With smaller removable panels, a single panel may be removed for service or replacement. 
     Furthermore, removable panels create joints between the panels. These joints can be sources of misalignment between panels, which may cause an image that spans many panels to be distorted. In addition, these joints may lead to problems with protecting the LEDs, lights, circuit boards, and other electronic components from damage due to environmental factors. 
     Therefore, there is a need for an electronic display capable of displaying an adaptable image that can be easily serviced from both the front and the rear. Furthermore, there is a need for a modular design wherein the electronic display comprises a plurality of removable panels that are easily removable from both the front and rear for service or replacement. There is also a need to protect the electronic elements of the display apparatus and removable panels from environmental elements to increase the service life, reliability, and performance of the removable panels. In addition, there is a need for easily aligning these removable panels relative to each other to minimize image distortion for images that span multiple removable panels. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides electronic display apparatuses and methods of making the apparatuses, as well as removable panels configured as portions of a modular design for the electronic displays, wherein the removable panels may be attached and removed from both the front and rear of the electronic display. The removable panels may also be configured for attachment to a frame in such a manner that electronic elements are substantially protected from potentially damaging environmental elements. 
     One embodiment of the present invention comprises a display module for displaying an adaptable image or a portion of an adaptable image. The display module includes a removable panel including a plurality of apertures formed through the removable panel. The plurality of apertures are arranged as at least one pixel row comprising a plurality of pixel arrangements distributed along the at least one pixel row. Each pixel arrangement includes at least one aperture of the plurality of apertures. The display module also includes a plurality of coupling devices attached to the removable panel. The coupling devices are configured for detachably coupling the removable panel to a frame member, wherein the coupling devices may be operated to attach or remove the removable panel. Furthermore, the coupling devices are configured such that they can be operated from a front side of the removable panel or from a back side of the removable panel. 
     Another embodiment of the present invention comprises display apparatus for displaying an adaptable image. The display apparatus includes a plurality of frame members to form a frame for the display apparatus and a plurality of display modules configured for displaying an adaptable image or a portion of an adaptable image. The display module includes a removable panel including a plurality of apertures formed through the removable panel. The plurality of apertures is arranged as at least one pixel row comprising a plurality of pixel arrangements distributed along the at least one pixel row. Each pixel arrangement includes at least one aperture of the plurality of apertures. The display module also includes a plurality of coupling devices attached to the removable panel. The coupling devices are configured for detachably coupling the removable panel to a frame member, wherein the coupling devices may be operated to attach or remove the removable panel. Furthermore, the coupling devices are configured such that they can be operated from a front side of the removable panel or from a back side of the removable panel. In addition, each display module of the plurality of display modules is coupled to at least one of the frame members to form a matrix organization of display modules for the display apparatus. 
     Yet another embodiment of the present invention comprises a method of making a display apparatus, comprising forming a removable panel and forming a plurality of apertures through the removable panel such that the plurality of apertures is arranged in at least one pixel row. Each pixel row includes a plurality of pixel arrangements distributed along the pixel row wherein each pixel arrangement includes at least one of the plurality of apertures. The method also includes attaching a plurality of coupling devices to the removable panel, wherein the coupling devices are configured for detachable coupling to a frame member. Furthermore, the coupling devices are configured such that they can be operated from a front side of the removable panel or from a back side of the removable panel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, which illustrate what is currently considered to be the best mode for carrying out the invention: 
         FIG. 1A  is a perspective view illustrating a front portion of a removable panel according to a representative embodiment of the present invention; 
         FIG. 1B  is a perspective view illustrating a rear portion of a removable panel according to a representative embodiment of the present invention; 
         FIG. 1C  illustrates a front view of a removable panel according to a representative embodiment of the present invention; 
         FIG. 2  illustrates a plurality of removable panels arranged in a matrix organization; 
         FIG. 3  illustrates an exploded view of removable panels for attachment to frame members; 
         FIG. 4A  illustrates a frame member and two removable panels prior to attachment; 
         FIG. 4B  illustrates a frame member and two removable panels after attachment; 
         FIG. 5  shows one removable panel above another removable panel to illustrate how they adjoin vertically to provide protection from environmental elements; 
         FIG. 6A  illustrates a representative embodiment of some pixel arrangements; 
         FIG. 6B  illustrates a side view of LEDs forming one pixel on a portion of a circuit board and a portion of a removable panel showing one pixel arrangement; 
         FIG. 6C  shows the circuit board portion and removable panel portion of  FIG. 6B  assembled together; and 
         FIG. 6D  shows the assembly of  FIG. 6C  with a sealant disposed in a recess of the removable panel. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention provides apparatuses and methods of making the apparatuses for electronic displays and removable panels configured as portions of a modular design for the electronic displays, wherein the removable panels may be attached and removed from both the front and rear of the electronic display. The removable panels may also be configured for attachment to a frame such that electronic elements are substantially protected from potentially damaging environmental elements. 
       FIGS. 1A and 1B  illustrate a front portion and a rear portion, respectively, of a display module  100  according to a representative embodiment of the present invention. A plurality of display modules  100  may be organized together to form a display apparatus. The display module  100  includes a removable panel  110 , which includes a plurality of apertures  135  (which may also be referred to herein as pixel holes, or simply as holes) formed though the removable panel  110 . The removable panel  110  may include multiple pixel rows  120 , wherein each pixel row  120  includes a plurality of pixel arrangements  130 , and each pixel arrangement  130  may include three apertures  135  for receiving light-emitting diodes (LEDs) (not shown), or other suitable light-emitting devices. Although the removable panel  110  is illustrated with a plurality of rows, those of ordinary skill in the art will recognize that within the scope of the present invention, the removable panel  110  may be formed of a single pixel row  120 . The removable panel  110  may be formed of any suitable material, such as, for example, plastic, fiberglass, or metal. 
     In the representative embodiments illustrated herein, the display module  100  includes a horizontal fin  140  (which may also be referred to herein as a louver) disposed above each pixel row  120  for shading the LEDs. The horizontal fin  140  creates a means for shading the pixel arrangements  130  from direct sunlight when installed outdoors, or from overhead light when installed indoors. Consequently, the horizontal fin  140  enables a higher contrast ratio, which may assist in viewing the billboard and making an adaptable image appear as if it includes greater intensity and more vibrant colors. In addition, the horizontal fins  140  may assist in drawing heat away from the LEDs and circuitry mounted behind the removable panel  110 . In the representative embodiments illustrated herein, the removable panel  110  is formed of plastic with the horizontal fins  140  also formed of plastic and as an integral part of the removable panel  110 . However, the horizontal fins  140  may be formed separately and, for example, be overlayed onto the front of the removable panel  110 . Embodiments of the present invention also may be formed of a dark colored material, which may further enhance the contrast ratio. 
     The removable panel  110  includes a front side  150 , a back side  152 , a protrusion  162  (shown in more detail in  FIG. 5 ) extending from a top side  154 , and a receiving rim  164  (shown in more detail in  FIG. 5 ) along a bottom side  156 . Also shown in  FIGS. 1A and 1B  are a right side protrusion  158  and a left side protrusion  160  extending from the front side  150  of the removable panel  110  toward the back side  152  of the removable panel  110 . Spacers  185  may be disposed on the back side  152 , which may be used to create an offset of a circuit board relative to the back side  152  of the removable panel  110  as is explained more fully below with respect to  FIGS. 6A-6D . 
     For attachment, the representative embodiment of the removable panel  110  illustrated in  FIGS. 1A ,  1 B, and  1 C includes four coupler holes  180  formed through the removable panel  110 . These coupler holes  180  are configured for receiving coupling devices (not shown) that may be used for coupling the removable panel  110  to frame members of a full display apparatus. Of course, the other embodiments of the removable panel  110  may include less than, or more than, the four coupler holes  180  illustrated in  FIGS. 1A-1C . 
       FIG. 1C  illustrates a front view of the removable panel  110  according to the representative embodiment of the present invention illustrated in  FIGS. 1A and 1B .  FIG. 1C  more clearly illustrates a representative placement of pixels arrangements along the pixel rows  120  and the three apertures  135  for each pixel arrangement  130 .  FIG. 1C  also illustrates the coupler holes  180  in the removable panel  110  configured for receiving coupling devices  190 , which may be used to attach the removable panel  110  to a frame. The coupling devices  190  and attachment of the removable panel  110  to a frame are shown in  FIGS. 4A and 4B  and are explained more fully below in the discussion of those figures. Also shown are recesses  170 , wherein each recess  170  encompasses the three apertures  135  comprising a pixel arrangement  130 . The recesses  170  may be seen in more detail in  FIGS. 6A-6D  and are explained more fully below in the discussion of  FIGS. 6A-6D . 
     Of course, those of ordinary skill in the art will recognize that other pixel arrangements  130  are contemplated within the scope of the present invention. For example, a pixel arrangement  130  may include a single hole for a single light element or two holes for two light elements such as, for example, LEDs. Such a configuration of one or two LEDs may be used for a monochrome display, or may be configured with multi-color LEDs for each pixel, such that a multi-color display may be achieved even from a single LED for each pixel. In the representative embodiments illustrated herein, three holes are used for a pixel arrangement  130  such that the light from a red LED, a green LED, and a blue LED may be combined to generate any possible color for a full color spectrum video display capable of showing still images and video images using conventional computer color maps. In addition, in some cases it may be desirable to include different colors of LEDs, or include more than one LED of the same color. As a result, pixel arrangements  130  may also include four or more apertures  135  for including a variety of LED colors. 
       FIG. 2  illustrates a plurality of display modules  100  arranged in a matrix organization to comprise a display apparatus  200 . These modules may be arranged in a variety of configurations for different applications. For example, the matrix organization may include a single row of removable panels  110  (or a single column of removable panels  110 ) for creating a narrow yet long display, which may be suitable for displaying messages in a traveling ticker-tape type of arrangement. A small number of removable panels  110  may be used to create a relatively small display apparatus  200 , or a large number of removable panels  110  may be arranged to create a relatively large display apparatus  200 . By way of example, and not limitation, a relatively large billboard size display apparatus  200  may include a matrix organization of 1100 or more removable panels  110  in a rectangular configuration. 
       FIG. 3  illustrates an exploded view of display modules  100  for attachment to frame members  210  as part of the display apparatus  200 . In the presently described embodiment, the frame members  210  extend vertically and each removable panel  110  may be placed in a removable panel position  205  such that it abuts a neighboring display module  100  horizontally. The display modules  100  also may be stacked vertically to form the overall display apparatus  200  for presenting the adaptable image. The overall display apparatus  200  may be configured to display an adaptable image, such as, for example, a series of still images, or a video image. In many embodiments, which include many display modules  100 , each display module  100  may be configured to form only a relatively small portion of the overall adaptable image. As a result, alignment and registration of the various display modules  100  relative to each other may be important to present a large, coherent image. Features of representative embodiments of the present invention include means for enabling this alignment and registration as the display modules  100  are attached to the frame members  210  at the various removable panel positions  205  of the display apparatus  200 . 
       FIG. 4A  illustrates a cross-sectional view of a frame member  210  and two removable panels ( 110 L and  110 R) prior to attachment and  FIG. 4B  illustrates a cross-sectional view of the frame member  210  and two removable panels ( 110 L and  110 R) after attachment to the frame member  210 . The frame member  210  includes a vertical channel  220  that runs along substantially the length of the frame member  210 . The frame member  210  is shown in a cross-sectional view, therefore, the vertical direction of the channel  220  refers to its running the vertical length of the frame member  210  as it is oriented vertically as part of the display apparatus  200 , rather than the vertical direction of the cross-sectional figure. The frame member  210  illustrated in  FIGS. 4A and 4B  is illustrated generally as an I-beam type configuration. However, those of ordinary skill in the art will recognize that many other configurations and cross-sections for the frame member  210  are possible and are contemplated within the scope of the present invention. 
     As mentioned previously, the removable panels ( 110 L and  110 R) include a right side protrusion  158  and a left side protrusion  160  at the sides of the removable panels ( 110 L and  110 R). The right side protrusion  158  and the left side protrusion  160  are configured such that they can abut against each other and both protrusions  158 ,  160  can fit at least partially inside of the vertical channel  220 . This abutting arrangement, and the disposition inside the vertical channel  220  substantially aligns multiple removable panels  110  in the vertical direction of the overall display apparatus  200 , as well as the depth of placement relative to the face of the frame member  210  (i.e., vertically in the cross-sectional drawing). In addition, the abutting arrangement and disposition in the vertical channel  220  creates a seal that provides substantial protection from encroachment of water, air, and other contaminants along the left sides and right sides of the removable panels  110 . 
     To form an enhanced seal, a gasket  225  may be disposed in the vertical channel  220  prior to disposing the right side protrusion  158  and left side protrusion  160  in the vertical channel  220 . This gasket  225  may be formed of any partially deformable material suitable for accepting the right side and left side protrusions ( 158  and  160 ) and making a substantially watertight seal, such as, for example, any suitable sealant, caulking, foam, rubber gasket, or other gasket-type material. 
     Also illustrated in  FIGS. 4A and 4B  are attachment holes  215  formed through the front face of the frame member  210  and the coupling devices  190  attached to the removable panels  110 .  FIG. 4B  illustrates the frame member  210  and the two removable panels ( 110 L and  110 R) after attachment using the coupling devices  190 . The coupling devices  190  are configured such that when they are attached to the removable panel  110  they can be operated from the front of the removable panel  110  or from the back of the removable panel  110  for attachment of the removable panel  110  to the frame member  210 . The coupling devices  190  may be any suitable attachment device, such as a screw, bolt, fastener, retainer, and the like. 
     The representative embodiment of the coupling devices  190  illustrated in  FIGS. 4A and 4B  also illustrates a front adjustment adaptor  193  on a front face of the coupling device  190  and a rear adjustment adaptor  198  on the rear face of the coupling device  190 . These adjustment adaptors may be any adaptor suitable for operating the coupling devices  190 . By way of example, and not limitation, if the coupling devices  190  are operated by rotation, the front and rear adjustment adaptors  193 ,  198  may be a screwdriver slot, a Phillips head slot, a square key, a hex key, a star key, a hex head, a square head, a wing-nut, and the like. 
     Furthermore, the representative embodiment of the coupling devices  190  illustrated in  FIGS. 4A and 4B  is configured with flanges  192  on opposite sides of a substantially cylindrical coupling device  190 . In attaching the removable panels ( 110 L and  110 R) to the frame members  210 , the flanges  192  may be aligned with key slots  218  (as shown in cut-away bottom view  216 ) in the attachment holes  215  of the frame member  210 . After aligning the flanges  192  with the key slots and placing the coupling devices  190  inside the attachment holes  215 , the flanges  192  protrude through to the back side of the frame member  210  such that about a quarter turn of the coupling device  190  in a first direction will fasten the removable panel  110  to the frame member  210  by the flanges  192  being seated against the back side of the frame member  210 . After attachment, about a quarter turn of the coupling device  190  in a second direction will align the flanges  192  on the coupling device  190  with the key slots in the attachment holes  215  such that the coupling device  190  may slide through the attachment hole  215  and the removable panel  110  is enabled for removal. With the coupling devices  190  operated for removal, the removable panel  110  may be pulled free from the frame member  210 . Due to an overlap mechanism, described more fully below with respect to  FIG. 5 , the removable panel  110  may need to be rotated slightly such that the lower portion of the removable panel  110  is pulled free from the frame member  210  first to enable the protrusion  162  ( FIG. 1C ) at the top of the removable panel  110  to be pulled free from under the removable panel  110  that is positioned above the removable panel  110  that is being removed. 
       FIG. 5  shows one removable panel above another removable panel to illustrate the overlap mechanism and how the removable panels adjoin to provide further protection from environmental elements. A lower removable panel  110 L illustrates the protrusion  162  extending from the top of the lower removable panel  110 L. An upper removable panel  110 U illustrates a rabbet-type configuration formed in the bottom side of the upper removable panel  110 U for receiving the protrusion  162  from the lower removable panel  110 L. The rabbet-type configuration includes a receiving rim  164 , such that when the lower removable panel  110 L and upper removable panel  110 U are joined, the receiving rim  164  of the upper removable panel  110 U overlaps and cooperatively engages the protrusion  162  of the lower removable panel  110 L in a shingle-type arrangement. 
     In a dry fit configuration, this shingle-type arrangement creates a seal that provides substantial protection from water, air, and contaminant encroachment along the top sides and bottom sides of the removable panels  110 . For additional protection, a sealant (not shown) may be applied between the upper removable panel  110 U and the lower removable panel  110 L, or between the protrusion  162  and the receiving rim  164 , to provide a more robust seal. The sealant may be any suitable sealant, caulking, foam, or gasket type material that can form a substantially watertight seal. 
       FIG. 6A  illustrates a representative embodiment of a representative pixel arrangement  130  in the removable panel  110 . In this embodiment, each pixel arrangement  130  includes three apertures  135  and is encompassed by a recess  170 . 
       FIG. 6B  illustrates a side view of the representative pixel arrangement  130  in the removable panel  110  showing the apertures  135  and the recess  170 . Also shown in  FIG. 6B  is a circuit board  300  bearing three LEDs  310  prior to the circuit board  300  being coupled to the removable panel  110 . As stated earlier, using three LEDs  310  to form a pixel is one possible embodiment of a pixel wherein the LEDs  310  may comprise a red LED, a green LED and a blue LED. 
     In many conventional display boards using LEDs  310 , the circuit board  300  bearing the LEDs  310  is covered with a potting material to cover the circuit board  300  and the lower portions of the LEDs  310 . This potting material may act to protect the LEDs  310  and circuit board  300  from environmental elements. However, potting material on the circuit board, around the ICs, components and the leads of the LEDs increases thermal resistance, impeding heat transfer away into the air. Furthermore, when LEDs  310  are soldered into a circuit board  300 , there may be misalignment between neighboring LEDs  310  and the LEDs  310  may be mounted at a slight angle. This angle and misalignment may be noticeable to a viewer and may create patterning in an overall image. Finally, potting materials generally have a relatively low durometer value. As a result, the potting material may not be stiff enough to hold the LEDs firmly in place to prevent additional misalignment from fabrication and handling processes. 
     Representative embodiments of the present invention use the more precise placement of the apertures  135  in the removable panel  110  for precise positioning and placement of the LEDs  310  installed on the circuit board  300 .  FIG. 6C  shows the circuit board  300  portion and removable panel  110  portion of  FIG. 6B  assembled together with the LEDs  310  penetrating through the apertures  135  and extending partially into the recess  170 . As the circuit board  300  and removable panel  110  are brought together, relatively small misalignment in the LEDs  310  or angled placement of the LEDs  310  may be corrected by the LEDs  310  fitting in to the more precise placement of the apertures  135 . Recall from  FIG. 1B  that the back side  152  of the removable panel  110  may include spacers  185  disposed at various places. These spacers  185  (not shown in  FIGS. 6A-6D ) may be used to ensure a proper depth of penetration of the LEDs  310  into the apertures  135 . 
     Finally,  FIG. 6D  shows the assembly of  FIG. 6C  with a sealant  175  disposed in at least a portion of the recess  170  of the removable panel  110 . The sealant  175  is disposed in the recess  170  to form a seal around the sides of the LEDs  310  while still leaving the top portion of the LEDs  310  exposed for efficient transmission of the light generated by the LEDs  310 , as well as leaving the leads of the LEDs  310  exposed to circulating air below the removable panel  110 , which enhances cooling and prevents hot spots. The sealant  175  may be any suitable sealant, caulking, foam, or gasket-type material that can form a substantially watertight seal to protect a large portion of the LEDs  310  from exposure to the elements and prevent water and other contaminants from encroaching behind the removable panel  110  and affecting the base of the LEDs  310 , the circuit board  300 , and other components that may be attached to the circuit board  300 . The depth of sealant  175  may be adjusted depending on such factors as the desired amount of LEDs  310  exposed above the sealant  175 , height of the LEDs  310 , and spacing between the removable panel  110  and the circuit board  300 . 
     In one representative embodiment, a silicon sealant is disposed in the recess  170 . The silicon sealant, as well as other suitable sealants, may also provide some adhering characteristics to assist in holding the circuit board  300  in place relative to the removable panel  110 . Some representative embodiments may use the sealant  175  as a means for holding the circuit board  300  in place against the removable panel  110 . With these embodiments, a simple punch device may be used to push on the fronts of the LEDs  310  to separate the circuit board  300  from the removable panel  110  such that the circuit board  300  may be easily repaired or replaced. 
     Keeping the LEDs  310  cool provides additional life to the LEDs  310  and enables the LEDs  310  to retain their color characteristics with less degradation of color hue and intensity. By leaving the base of the LEDs  310 , the leads of the LEDs  310 , the circuit board  300  and components exposed to ambient air, heat may be more readily drawn away from the LEDs  310  to keep them relatively cool. 
     In  FIGS. 6A-6D , the recess  170  is illustrated to encompass a pixel including three LEDs  310 . However, other recesses  170  are contemplated within the scope of the present invention. By way of example, and not limitation, a recess  170  may be formed around each LED, a recess  170  may be formed to encompass more than one pixel arrangement  130 , and a recess  170  may be formed to encompass an entire pixel row. 
     While not illustrated, it will be understood by those of ordinary skill in the art that the removable panels  110  will be operably wired together and coupled to a controller configured for operating each of the removable panels  110 , each of the pixels on each removable panel  110 , and each color element LED within each pixel. Many wiring options may be possible, such as, for example, a serial connection between all of the panels such that the panels are essentially daisy-chained together. Furthermore, many controller configurations are possible for controlling the LEDs  310  and defining what adaptable images, in the form of still images or video, may be displayed on the display apparatus. 
     Although this invention has been described with reference to particular embodiments, the invention is not limited to these described embodiments. Rather, the invention is limited only by the appended claims, which include within their scope all equivalent devices or methods that operate according to the principles of the invention as described.