Patent Publication Number: US-2004041743-A1

Title: Display apparatus and method for distributed modules of light-emitting elements

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention generally relates to a display apparatus and a method for distributed modules of light-emitting elements and, more particularly, to a display apparatus for distributed modules of light-emitting elements with easy assembly, setup, removal, maintenance and re-use as well as adjustable size and aspect ratio and a display method for such an apparatus. The display apparatus possesses excellent display size/weight ratio with single-sided or double-sided display capabilities.  
       [0003] 2. Description of the Prior Art The light-emitting diode (to be abbreviated as LED hereinafter) has received considerable attention for such advantages as high brightness, excellent durability, low heat generation, low power consumption, no limitation of display format, low reflectivity against sunlight, suitability for use in fabrication of large-scale displays, etc. and has been widely used such applications as display panels, traffic signs and indoor/outdoor display boards. Furthermore, the prior art dynamic full-color video display board employs LEDs as light-emitting elements.  
       [0004] Even though mass production of full-color LED-based display boards can be achieved by using the disclosures in the prior arts, the cost of high-brightness blue/green LEDs is still high compared to that of red/yellow ones.  
       [0005] As a result, a mere growth rate of 12% is achieved in the global market of LED-based signs/displays (See Table I) as quoted by website AsiaMoney.com.tw (http://www.asiamoney.com.tw/research/report/001226 — 1 — 2.htm). Table I—Global Market for LED-based Signs/Displays (Unit: million USD)  
                                                           Year   1999   2000   2003                                                            LED-based   522   598   843           Signs/Displays           Growth rate   —   14.56%   12.13%                                  
 
       [0006] The inventors of the present invention have examined and summarized limiting factors of the LED-based industry into two aspects.  
       [0007] 1. Module Aspect:  
       [0008] The conventional large-scale display employing LEDs as light-emitting elements typically comprises module cases that contribute a largest percentage of the total system weight. Since display requirements vary in different occasions, a display configuration is usually dedicated for permanent usage at a particular location. Therefore, the number and pitch of LEDs forming a cluster are designed according to individual requirements.  
       [0009] In order to reduce the cost for manufacturing a display, a panel-type unit has been developed. In most cases, various accessories (mechanical in particular) for different displays are not compatible with one another.  
       [0010] As shown in FIG. 1, a conventional cluster  10  comprises a shell  11 ; a printed circuit board  12  disposed inside the shell  11 ; a plurality of LED elements  13  disposed on the front side of the shell  11 , the pins of the LED element  13  being soldered with the printed circuit board  12 ; a wiring  14  having a first end connected to a driving circuit (not shown) via a connector  15  and a second end connected to the printed circuit board  12  via an opening (not shown) on the rear side of the shell  11 , the joint between the wiring  14  and the printed circuit board  12  being filled with water-proof material such as epoxy and silicon after the wiring  11  is soldered to the printed circuit board  12 . Lacking automated production setup, processes for manufacturing clusters are complex. More particularly, the aforementioned soldering and water-proof material filling processes are performed manually. The reliability manual processes provide is relatively poor, adversely affecting the yield of clusters. Moreover, the cost for manufacturing clusters constitutes a large percentage of manufacturing an entire display. Therefore, manual processes often cause poor reliability and high fabrication cost for the cluster and the entire display alike. Personnel are dispatched on the front side and the rear side for installing and attaching the cluster  10 , respectively, costing valuable time and labor. Though the panel-type unit can replace a single cluster for fewer processing steps, it is far from perfect when compared with the present invention.  
       [0011] 2. Application Aspect:  
       [0012] As described above, the design of a large-scale display board is based on module cases and clusters. The whole structure is considerably heavy and thus suitable for immobile or long-term applications such as professional baseball parks, football stadiums and arenas. For occasional applications in concerts, World Cup and Olympic Games, large-scale displays are in great demand for a certain period of time. The need arises for large-scale display apparatuses with distributed modules of light-emitting elements. Such apparatuses do not exist despite their advantages: 
       [0013] 1. Easy assembly, disassembly and maintenance.  
       [0014] 2. Flexibility for repeated applications at various locations.  
       [0015] 3. Size and aspect ratio versatility. 
       [0016] In view of the above drawbacks, a few improved structures for large-scale displays have been disclosed. Examples are provided below:  
       [0017] (1) U.S. Pat. No. 6,208,073 “Smart light emitting diode cluster and system” filed by Wang et al. provides a cluster, having drive circuits and data processing boards, as an individual pixel for data receiving and transmission. One advantage of the LED cluster system of subject patent is replaceable display elements. The system is suitable for advertising purposes because it is relatively light. However, the structure of the LED cluster system has to be designed individually according to practical cases, and the assembly steps are complicated. For example, a great amount of sequenced circuitry with software enhancement is required such that well-trained staffs accompanied with skilled engineers are necessary so as to complete the system. Even though the display elements employed in the LED cluster system are for general purposes, the cost and skills for assembly are much higher compared to those of the present invention.  
       [0018] (2) In U.S. Pat. No. 6,065,854 “LED modular display system” filed by West et al., the percentage of mechanisms in weight of the system is reduced with the use of a supporting member with triangular cross-section to replace the steel structure. Moreover, the LED modules include inwardly tapered vertical sidewalls and horizontal upper and lower trapezoidal faces such that the display system is advantageous in easy maintenance, and re-setup. However, compared to the present invention, some portions of the LED modular display system are not recyclable.  
       [0019] (3) U.S. Pat. No. 5,900,850 “Portable large-scale image display system” filed by Bailey et al. provides a portable and foldable large-scale image display system having netlike structures disposed on the steel structure. The netlike panels are distributed over a large-scale steel structure so as to function as a display board. After usage, the display system is foldable. Therefore, the portable large-scale image display system is advantageous in high area/weight ratio and easy removal, and it is thus suitable for use in non-permanent occasions. However, the portable display system is inferior to the present invention, as described hereinafter:  
       [0020] a. The netlike panels are not parts of the structure.  
       [0021] b. In spite of flexibility and easy removal, the fabrication as well as maintenance of components such as belts, clips and stitches connected to the panels fixed on the structure frame is troublesome and the assembly processing requires great amount of time and labor, resulting an increased cost.  
       [0022] (4) U.S. Pat. No. 6,237,290 “High-rise building with large scale display device inside transparent glass exterior” filed by Tokimoto et al. discloses a large-scale display disposed inside a transparent glass exterior to comprise a plurality of louver structured modules. Such a large-scale display device does not affect the building&#39;s appearance and is free of water permeation. However, the display device is designed individually according to the appearance as well as the structure employed, therefore it is limited compared to the present invention.  
       [0023] (5) U.S. Pat. No. 6,362,801 “Display apparatus” filed by Yuhara et al. discloses a display apparatus disposed on a 3-dimensional curve surface of a flexible net member instead of a conventional heavy steel structure so as to possess high flexibility, easy removal and low-cost setup. However, compared to the present invention, this prior art is disadvantageous in that the location and orientation of the light-emitting elements are not identical and it is thus difficult to maintain precise pitch and luminance. Moreover, this prior art also suffers from complicated circuitry and time-consuming labor.  
       SUMMARY OF THE INVENTION  
       [0024] Therefore, it is a primary object of the present invention to provide a display apparatus for distributed modules of light-emitting elements with easy assembly, setup, removal, maintenance and re-use as well as adjustable size and aspect ratio and a display method of such an apparatus. The display apparatus possesses high display size/weight ratio with single-sided or double-sided display and is suitable for use in temporary display sites.  
       [0025] In the display apparatus for distributed modules of light-emitting elements according to the present invention, a plurality of total passive clusters (TP clusters) and an active control module (AC module) are electrically attached onto a tube-shaped electrical structure module (ES module) via clips on the TP clusters and the AC module and grooves on the ES module such that easy assembly, setup, removal, maintenance and re-use can be achieved so as to adjust the display size; therefore, the display apparatus possesses excellent display size/weight ratio with single-sided or double-sided display and is suitable for use in temporary display sites. Identical TP clusters and AC modules can be attached onto different ES modules for various luminance intensities and pitches to fulfill a full-color display. Furthermore, a roll-up mechanism may also be provided so as to unfold or fold the display.  
       [0026] More particularly, it is a primary object of the present invention to provide a display apparatus and a method for distributed modules of light-emitting elements, comprising a plurality of TP clusters and an AC module electrically attached onto a tube-shaped ES module via clips on the TP clusters and the AC module and grooves on the ES module.  
       [0027] It is another object of the present invention to provide a display apparatus and a method for distributed modules of light-emitting elements with easy assembly, setup, removal, maintenance and re-use.  
       [0028] It is still another object of the present invention to provide a display apparatus and a method for distributed modules of light-emitting elements with adjustable size and aspect ratio.  
       [0029] It is still another object of the present invention to provide a display apparatus and a method for distributed modules of light-emitting elements with high display size/weight ratio.  
       [0030] It is still another object of the present invention to provide a display apparatus and a method for distributed modules of light-emitting elements with single-sided or double-sided display.  
       [0031] It is still another object of the present invention to provide a display apparatus and a method for distributed modules of light-emitting elements suitable for use in temporary display sites.  
       [0032] It is still another object of the present invention to provide a display apparatus and a method for distributed modules of light-emitting elements, in which identical TP clusters and AC modules can be attached onto different ES modules for various luminance intensity and pitches to fulfill a full-color display.  
       [0033] It is yet another object of the present invention to provide a display apparatus and a method for distributed modules of light-emitting elements, provided with a roll-up mechanism so as to unfold or fold the display.  
       [0034] Other and further features, advantages and benefits of the invention will become apparent in the following description taken in conjunction with the following drawings. It is to be understood that the foregoing general description and following detailed description are exemplary and explanatory but are not to be restrictive of the invention. The accompanying drawings are incorporated in and constitute a part of this application and, together with the description, serve to explain the principles of the invention in general terms. Like numerals refer to like parts throughout the disclosure. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0035] The objects, spirits and advantages of the preferred embodiment of the present invention will be readily understood by the accompanying drawings and detailed descriptions, wherein:  
     [0036]FIG. 1 is a schematic diagram showing a conventional cluster  10  in accordance with the prior art;  
     [0037]FIG. 2 is a schematic diagram showing a display apparatus  20  for distributed modules of light-emitting elements in accordance with the present invention;  
     [0038]FIG. 3A is a flow chart showing data process from a data/address bus to an addressable display module  24  in accordance with the present invention;  
     [0039]FIG. 3B is a schematic diagram showing an addressable display module  24  in accordance with the present invention;  
     [0040]FIG. 4A is an exploded view showing a total passive cluster  241  in accordance with the present invention;  
     [0041]FIG. 4B shows, from left to right, a front view, a side view and a back view of a circuit board  241   b  in accordance with the present invention;  
     [0042]FIGS. 4C, 4D and  4 E are, respectively, a front view, a side view and a back view of a completed total passive cluster  241  in accordance with the present invention;  
     [0043]FIG. 5 is a schematic diagram showing a total passive cluster  241  attached onto an electrical structure module  242  in accordance with the present invention;  
     [0044]FIG. 6 is a cross-sectional view showing an electrical structure module  242  with a plurality of total passive clusters  241  on both sides in accordance with the present invention;  
     [0045]FIGS. 7A, 7B and  7 C are, respectively, a top view, a front view and a side view of a matrix-type video display apparatus  30  in accordance with the present invention; and  
     [0046]FIGS. 8A and 8B are, respectively, a front view and a side view of a rolled-up type video display  40  in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0047] The present invention providing a display apparatus and a method for distributed modules of light-emitting elements can be exemplified by the preferred embodiment as described hereinafter.  
     [0048] As shown in FIG. 2, the present invention discloses a display apparatus  20  for distributed modules of light-emitting elements comprising a central controller  22  and a plurality of addressable display modules  24  (referred to as “display modules” for short hereinafter). The backside of the central controller  22  is connected with the plurality of addressable display modules  24 .  
     [0049] Control data and video data are transmitted to a data receiver  221  of the central controller  22  via a network  21  (for example, Internet or Intranet). The data receiver  221  outputs the control data and pixel data in the video data into a location mapping controller  222  so as to perform location mapping. The location mapping controller  222  is connected to an electrically erasable programmable read-only memory (EEPROM) IC  223  and a memory IC  224 . A location mapping table is stored and accessed by the EEPROM IC  223  and a location mapping process is performed with the assistance from the memory IC  224 . The pixel data and control data having experienced the location mapping process is then transmitted into an image property controller  225  so as to adjust the image property parameter (such as Gamma value). The image property controller  225  is connected to an EEPROM IC  226  and a memory IC  227 . A mapping table is stored and accessed by the EEPROM IC  226  and an image property parameter adjusting process is performed with the assistance from the memory IC  227 . A plurality of packet data conforming to pre-determined display conditions and mapped onto respective AC modules are transmitted from the central controller  22  through a data/address bus  228  into a plurality of display modules  24  so as to perform the display driving process.  
     [0050]FIG. 3A is a flow chart showing data process from a data/address bus  228  in FIG. 2 to an addressable display module  24 , and FIG. 3B is a schematic diagram showing an addressable display module  24 . In FIG. 3A and FIG. 3B, a display module  24  comprises a plurality of total passive (TP) clusters  241 ; an electrical structure (ES) module  242 ; and an active control (AC) module  243 . As shown in FIG. 3A, the AC module  243  comprises a data receiver  243   a , a data processor  243   b  and a driving circuit  243   c . A packet data transmitted from the data/address bus  228  and mapped onto the AC module  243  is input into the data processor  243   b  through a wiring (not shown) of the ES module  242  and the data receiver  243   a  to experience data processing. The data having experienced data processing is then input into the driving circuit  243   c  so as to drive the plurality of total passive (TP) clusters  241 . Each of the plurality of TP clusters  241  is a light-emitting unit composed of a plurality of light-emitting elements (abbreviated as LEE&#39;s) such as light-emitting diodes (abbreviated as LEDs), organic light-emitting diodes (abbreviated as OLEDs) or other light-emitting devices. The plurality of TP clusters  241  are driven by the driving circuit  243   c  and simultaneously emit light according to the processed data. Therefore, the TP clusters  241  and the ES module  242  are passive module. More particularly, the AC module  243  is used for processing the data and driving the passive LEE&#39;s in the TP clusters  241 , while the ES module  242  is used for constructing the structure and serves as an interface both structurally and electrically. The AC module  243  is connected to the ES module  242  through the data/address bus  228  so as to receive the corresponding video and control data. The video and control data having experienced data processing controls the driving circuit  243   c  and then drives the TP clusters  241  through the ES module  242  so as to emit light and display video.  
     [0051]FIG. 4A is an exploded view showing a total passive cluster  241  in accordance with the present invention. In FIG. 4A, the total passive cluster  241  comprises sixteen LEE&#39;s  241   a , a printed circuit board  241   b  and a shell  241   c  formed by plastic injection. The pins  241   d  of the sixteen LEE&#39;s  241   a  are connected to corresponding contacts  241   e  on the printed circuit board (referred to as “circuit board” for short hereinafter)  241   b . On the shell  241   c  is formed a window  24   f.    
     [0052]FIG. 4B shows, from left to right, a front view, a side view and a back view of a circuit board  241   b  in accordance with one preferred embodiment of the present invention. The circuit board  241   b  is installed inside the shell  241   c , at the center on the backside of which are disposed eight contacts  241   g  exposed in the window  241   f  of the shell  241   c . FIGS. 4C, 4D and  4 E are, respectively, a front view, a side view and a back view of a completed total passive cluster  241 . In FIG. 4C, there are eight R&#39;s, four G&#39;s and four B&#39;s, representing eight red LEE&#39;s, four green LEE&#39;s and four blue LEE&#39;s, respectively, to form a TP cluster  241  composed of sixteen LEE&#39;s  241   a . In FIG. 4D, there are shown a plurality of LEE&#39;s  241   a  on the left, an upper lid  241   h  at the top and a lower lid  241   i  at the bottom. On the upper lid  241   h  and the lower lid  241   i , there are disposed an upper clip 241 j  and a lower clip  241   k , respectively. In FIG. 4E, there are disposed two locating pins  241   l  for connecting and locating the ES module  242 . Exposed in the window  241   f  at the center of FIG. 4E are eight contacts  241   g  on the backside of the circuit board  241   b.    
     [0053]FIG. 5 is a schematic diagram showing a TP cluster  241  attached onto a portion of the ES module  242 . On the top of the ES module  242  are disposed a first groove  242   a  and a second groove  242   b , while at the bottom of the ES module  242  are disposed a third groove  242   c  and a fourth groove  242   d . On both sides of the ES module  242  are provided a plurality of connecting devices. On one side, a first connecting device  242   e  and a second connecting device  242   f  have the same structure. The second connecting device  242   f , for example, comprises two locating holes  242   i , a water-proof gasket  242   j  and a connector  242   g , on which there are disposed eight protruding contact springs  242   h . When each of the two locating holes  242   i  corresponds to one of the two locating pins  241   l , the compatibility between the shell  241   c  and the ES module  242  enables the lower lid  241   i  of the shell  241   c  to be attached onto the first groove  242   a  of the ES module  242  and the lower clip  241   k  to be attached onto the third groove  242   c  (not shown in FIG. 5) such that the eight contact springs  242   h  on the ES module  242  electrically connect the eight contacts  241   g  on the corresponding TP cluster  241 . Since the water-proof gasket  242   j  tightly contacts the TP cluster  241  such that the eight contacts are prevented form the rain and moisture.  
     [0054]FIG. 6 is a cross-sectional view showing the ES module  242  provided with a plurality of TP clusters  241  on both sides in accordance with the present invention. The interconnection mechanism between the ES module  242  and the TP clusters  241  has been described according to FIG. 5, and thus is omitted hereinafter. Located around the center portion of FIG. 6 is an ES module  242 , comprising a cannular aluminum-extruded tube structure for single-sided or double-sided display according to practical cases. When a double-sided display board is concerned, data transmission interface is composed of two circuit boards  242   k  and associated connectors (not shown) disposed in the cannular portion inside the ES module  242  along the tube-extending direction. Both the power and the data on the bus are transmitted through the components on circuit boards  242   k  to the AC module (not shown in FIG. 6). The TP clusters  241  are activated by the AC module via the components such that the plurality of LEE&#39;s  241   a  emit light. In FIG. 6, it is clear that the lower lid  241   i  of the shell  241   c  is attached onto the first groove  242   a  of the ES module  242  and the lower clip  241   k  is attached onto the third groove  242   c  such that the contact springs  242   h  on the ES module  242  electrically connect the contacts  241   g  on the corresponding TP cluster  241 . Since the water-proof gasket  242   j  tightly contacts the ES structure  242  and the TP cluster  241  such that the contacts are prevented form the rain and moisture.  
     [0055] The pitch angle (i.e., the angle relative to the horizontal level) of a TP cluster preferably embodied as 6° can be easily achieved during structural installation. An aluminum-extruded ES module is advantageous that the number and pitch of TP clusters can be easily changed according to practical cases. Different ES modules provide with different pitches so as to meet the requirements in different occasions. The TP clusters and the ES module can be embodied as standard products for easy assembly and re-use. Therefore, the user does not have to re-design the whole system when different requirements are concerned.  
     [0056] The interconnection mechanism between the AC module and the ES module is basically the same as that between the ES module  242  and the TP clusters  241  except that the number of contacts is not necessarily identical. In the display apparatus for distributed modules of light-emitting elements according to the present invention, the operation of all the components for data processing and driving is performed in the AC module, in which the control and video data are obtained by the ES module and then the control and video data having experienced data processing drive the TP clusters via the ES module. Such a design reduces the difficulties for assembly and maintenance and no staff skilled in the system structure is necessary. When a routine maintenance is performed, only the AC module or the TP cluster(s) is required to be updated. Furthermore, when the hardware or the firmware of the AC module is updated or upgraded, only the AC module is required to be changed so as to improve the display apparatus for distributed modules of light-emitting elements according to the present invention.  
     [0057] The most important merit of the display apparatus for distributed modules of light-emitting elements is that all the disclosed components (including elements and modules) can be re-used. Compared to the conventional LED-based display board in the prior arts, the present invention is advantageous in that:  
     [0058] 1. It is less difficult in assembling.  
     [0059] 2. All the components can be re-used.  
     [0060] 3. Easy maintenance can be achieved in the front and all the components can be easily updated, resulting in low maintenance cost.  
     [0061] 4. Only minor amendment is required for the ES module so as to meet different requirements without re-designing the whole system.  
     [0062] 5. It possesses higher size/weight ratio and less weight than other display boards with the same size.  
     [0063] 6. When a single-sided display board is concerned, only the ES module has to be rotated to a position that conforms to the preferable pitch angle; when a double-sided display board is concerned, only the aluminum-extruded shape of the ES module has to be changed so as to meet the preferable pitch angle.  
     [0064] 7. The components are simple and distributed to allow excellent heat dissipation such that a forcing convection-type heat-dissipating device is not required.  
     [0065] 8. An arc-shaped display board can be easily implemented according to an arc-shaped building.  
     [0066]FIGS. 7A, 7B and  7 C are, respectively, a top view, a front view and a side view of a matrix-type video display apparatus for distributed modules of light-emitting elements  30  (referred to as “matrix-type video display apparatus” for short hereinafter) in accordance with the present invention. In FIGS. 7A, 7B and  7 C, on both sides of a first holder  31  and a second holder  32  are disposed eighteen sockets  311  and  321  (nine on each side, respectively). Nine display modules from the first to the ninth  331  to  339  are composed of an ES module  34 , sixteen (for single-sided display) or thirty-two (for double-sided display) TP clusters and an AC module  36 , respectively, in the same manner as aforementioned. Two tenons (not shown) on both ends of each of the display modules  331  to  339  are disposed so as to have the display modules  331  to  339  plugged into the corresponding sockets  311  and  321  such that a matrix-type video display apparatus for distributed modules of light-emitting elements  30  is formed. Moreover, a third holder and a fourth holder (not shown) can be disposed on the left of the first holder  31  and the right of the second holder  32 , respectively. Nine display modules can be installed between the first holder  31  and the third holder, and nine display modules can also be installed between the second holder  32  and the fourth holder. Therefore, the matrix-type video display apparatus  30  of the present invention can be lengthen or shorten horizontally. Similarly, all of the first holder  31 , the second holder  32 , the third holder and the fourth holder can be lengthen or shorten. Accordingly, the matrix-type video display apparatus  30  of the present invention can be lengthen or shorten vertically. In other words, the display size and the size/weight ratio of the matrix-type video display apparatus  30  of the present invention can be adjusted at will. Furthermore, the pitch of neighboring TP clusters and the pitch of neighboring sockets  311  and  321  on the first holder and the second holder, respectively, can be easily adjusted too, so as to meet the requirements of various displays. In addition, there are various standard TP clusters to be chosen from for different display purposes.  
     [0067]FIGS. 8A and 8B are, respectively, a front view and a side view of a rolled-up type video display  40  for distributed modules of light-emitting elements (referred to as “rolled-up type video display” for short hereinafter) in accordance with the present invention. In FIGS. 8A and 8B, each of the display modules  43  comprising an ES module  44 , sixteen TP clusters  45  and an AC module  46  is similar to the display modules  331  to  339  of the matrix-type video display apparatus. The rolled-up type video display  40  differs from the matrix-type video display apparatus  30  in that both ends of the display module are connected to a first chain  41  and a second chain  42 , respectively. The topmost display module  43  or the top portions of the first chain  41  and the second chain  42  can be connected to a rotor  47  fixedly disposed via a holder onto an object such as a building. When in operation, the rotor  47  unfolds the display modules  43  in turn so as to display. On the contrary, when not in operation, the rotor  47  rotates in a reversed direction so as to fold the display modules  43  in turn. Moreover, the rotor  47  and the display modules  43  can be removed from the object and re-combined for another occasion. Furthermore, the rolled-up type video display  40  has all the advantages that the matrix-type video display apparatus  30  has. In addition, as shown in FIG. 8B, on both sides of the first chain  41  and the second chain  42  are provided with a plurality of structural holders  48  such that the TP clusters  45  and the AC module  46  are prevented being damaged from when the rotor  47  rotates.  
     [0068] Although this invention has been disclosed and illustrated with reference to a particular embodiment, the principles involved are susceptible for use in numerous other embodiments that will be apparent to persons skilled in the art. This invention is, therefore, to be limited only as indicated by the scope of the appended claims.