PATENT DOCUMENT

Publication Number: US-10288937-B2
Application Number: US-201615130763-A
Country: US
Kind Code: B2

Title: Display system with distributed LED backlight

Abstract:
A display system with a distributed LED backlight includes: providing a plurality of tile LED light sources, each tile LED light source having a tile and a plurality of similar LED light sources on each tile connected for emitting light therefrom; orienting the plurality of tile LED light sources for illuminating a display from the back of the display; and integrating the plurality of tile LED light sources into a thermally and mechanically structurally integrated distributed LED tile matrix backlight light source.

Claims:
What is claimed is: 
     
       1. A backlight unit comprising:
 a plurality of tiles, wherein each of the plurality of tiles has a planar portion on which a plurality of light-emitting diodes is mounted and a side portion that is bent away from the planar portion, wherein a first side portion of a first tile in the plurality of tiles overlaps and is connected to a second side portion of a second tile in the plurality of tiles; and 
 an array tray that supports the plurality of tiles, wherein the array tray has alternating ridges and grooves, and wherein the side portions are received in the grooves. 
 
     
     
       2. The backlight unit defined in  claim 1 , wherein the overlapping first and second side portions comprise aligned holes and wherein the backlight unit further comprises:
 a fastener that extends through the aligned holes to connect the first tile to the second tile. 
 
     
     
       3. The backlight unit defined in  claim 2 , wherein the fastener is a screw. 
     
     
       4. The backlight unit defined in  claim 1 , wherein each of the plurality of tiles has an additional side portion opposite the side portion, and wherein the additional side portion is bent away from the planar portion. 
     
     
       5. The backlight unit defined in  claim 4 , wherein the side portion and the additional side portion each include an opening. 
     
     
       6. The backlight unit defined in  claim 4 , wherein the side portion and the additional side portion extend downwardly from the planar portion. 
     
     
       7. The backlight unit defined in  claim 1 , wherein the planar portions overlap the ridges. 
     
     
       8. The backlight unit defined in  claim 1 , wherein the planar portion of each tile overlaps a ridge of the array tray. 
     
     
       9. The backlight unit defined in  claim 8 , wherein the planar portion of each tile has an upper surface on which the plurality of light-emitting diodes is mounted and wherein the side portion of each tile is bent away from the upper surface into one of the grooves. 
     
     
       10. A display comprising:
 a backlight assembly comprising:
 a rail having first and second opposing surfaces; 
 a plurality of tiles mounted to the rail, wherein each of the plurality of tiles comprises a planar portion that overlaps the first surface of the rail and a tile arm that extends from an edge of the planar portion and wraps around an edge of the rail from the first surface to the second surface; and 
 
 a plurality of light-emitting diodes mounted on the planar portion of each of the tiles. 
 
     
     
       11. The display defined in  claim 10 , wherein the tile arms attach the plurality of tiles to the rail. 
     
     
       12. The display defined in  claim 10 , wherein the rail comprises a protrusion that extends from the second surface. 
     
     
       13. The display defined in  claim 12 , wherein each of the plurality of tiles comprises an additional tile arm that extends from an opposing edge of the planar portion and wraps around an opposing edge of the rail from the first surface to the second surface. 
     
     
       14. The display defined in  claim 13 , wherein the protrusion extends between the tile arm and the additional tile arm. 
     
     
       15. The display defined in  claim 10 , wherein the tile arm comprises a spring finger that extends under the second surface of the rail. 
     
     
       16. The display defined in  claim 15 , wherein the second surface of the rail comprises a pocket in which the spring finger is received to secure each of the plurality of tiles to the rail. 
     
     
       17. A backlight assembly comprising:
 a plurality of tiles; 
 a plurality of light-emitting diodes mounted to each of the plurality of tiles; 
 a rail having a planar portion on which each of the plurality of tiles rests and a protrusion that extends from the planar portion to form a retaining channel, wherein a first edge of each of the plurality of tiles is received in the retaining channel; and 
 a retainer spring that is attached to the rail and that presses an opposing second edge of each of the plurality of tiles against the rail. 
 
     
     
       18. The backlight assembly defined in  claim 17 , wherein the protrusion overlaps the first edge of each of the plurality of tiles that is received in the retaining channel. 
     
     
       19. The backlight assembly defined in  claim 17  further comprising a fastener that extends into the rail to attach the retainer spring to the rail. 
     
     
       20. The backlight assembly defined in  claim 17  further comprising an array tray, wherein the rail is one of a plurality of rails that are attached to the array tray.

Description:
This application is a continuation of U.S. patent application Ser. No. 13/359,308, filed Jan. 26, 2012, which is a continuation of U.S. patent application Ser. No. 12/237,331, filed Sep. 24, 2008, now U.S. Pat. No. 8,104,911, which claims the benefit of U.S. provisional patent application No. 60/976,404, filed Sep. 28, 2007. This application claims the benefit of and claims priority to U.S. patent application Ser. No. 13/359,308, filed Jan. 26, 2012, U.S. patent application Ser. No. 12/237,331, filed Sep. 24, 2008, now U.S. Pat. No. 8,104,911, and U.S. provisional patent application No. 60/976,404, filed Sep. 28, 2007, each of which are hereby incorporated by reference herein in their entireties. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to display systems, and more particularly to a display system with a distributed LED backlight. 
     BACKGROUND 
     With the advance of display systems illumination technology from incandescent to fluorescent to solid-state light sources, and with ever-increasing miniaturization, one popular electronic category seems not to have kept pace. That category is large-sized personal data displays, such as personal computer monitors. 
     For many years, such monitors were based on cathode ray tube (“CRT”) technology. More recently, flat panel displays have increasingly displaced CRT displays. The most common form of flat panel displays utilizes one or more fluorescent light sources located behind a liquid crystal display (“LCD”) screen. Contemporary technology has enabled the use of cold cathode fluorescent light (“CCFL”) light sources, but because a cathode emitter is still required, a high voltage source for striking and maintaining an electric arc through the CCFL is also required. 
     With continuing improvements in light-emitting diode (“LED”) technology, such as substantial improvements in brightness, energy efficiency, color range, life expectancy, durability, robustness, and continual reductions in cost, LEDs have increasingly been of interest for superseding CCFLs in larger computer displays. Indeed, LEDs have already been widely adopted as the preferred light source in smaller display devices, such as those found on portable cellular telephones, personal data assistants (“PDAs”), personal music devices (such as Apple Inc.&#39;s iPod®), and so forth. 
     One reason for preferring LED light sources to CCFL backlight light sources is the substantially larger color gamma that can be provided by LED light sources. Typically, an LCD display that is illuminated by a CCFL backlight produces about 72-74 percent of the color gamma of a CRT-based NTSC display. (“NTSC” is the analog television system in use in Canada, Japan, South Korea, the Philippines, the United States, and some other countries.) Current LED backlight display technology, however, has the potential of producing 104-118 percent or more of that gamma color space. 
     Another reason for not preferring CCFL bulbs is that they contain environmentally unfriendly mercury, which could be advantageously eliminated if an acceptable LED backlight light source configuration could be developed for larger displays. 
     When implemented in small displays such as just described, the technical requirements are readily met. As is known in the art, the illumination intensity can be rendered uniform by distributing LED light sources around the periphery of the display and utilizing light diffusing layers behind the display to equalize the display intensity. The technical challenges are modest because the screens are modest in size, so that the individual display pixels are never very far from one or more of the LED light sources. Light attenuation caused by distance from the LED light sources is therefore not great and is readily equalized by appropriate LED positioning coupled with suitable light diffusers behind the display. 
     One way to envision the ease with which this challenge can be met in smaller displays is to consider the number of pixels, on average, that each LED light source must support in the display, and the maximum distances per pixel that the most distant pixels are located relative to a given LED light source. These numbers are modest (perhaps in the hundreds), so the light diminution or attenuation for the most distant pixels is similarly modest and readily compensated by suitable diffuser designs. 
     On the other hand, the larger geometries of typical flat panel computer monitors and displays (e.g., larger than about 20 inches) create area-to-perimeter ratios that have proven untenable for current LED technologies, particularly with respect to LED brightness or light output. This has meant that it has proven unsatisfactory to attempt to replace CCFL light sources with LED light sources along one or more edges of such larger display screens. Accordingly, such displays continue to employ CCFL light sources even though CCFL light sources are increasingly less desirable than LED light sources. 
     It would seem that a straightforward solution for replacing CCFL light sources with LEDs would then be to arrange the LEDs in some sort of array configuration behind the LCD display screen, rather than around the perimeter. Prior attempts to do so, however, have proven unsatisfactory. Commercially viable displays for general consumption must be economical to manufacture, thin, lightweight, and must provide efficient thermal management capability. Attempts to meet these criteria in acceptable form factors and costs have been unsuccessful. 
     Previous efforts to achieve these objectives have failed due to a number of practical obstacles. For example, even though LED light outputs have dramatically improved in recent years, a very large number of LEDs is still required to provide sufficient brightness in such larger displays. Typically, a minimum of several hundred LEDs must be used. This then requires an enormously large maze of wires and/or bulky circuit boards to mount, support, and power such a large number of LEDs in a distributed matrix configuration. This in turn requires adequate mechanical structure to support all those components behind the LED screen. The resulting structure is bulky, thick, heavy, and not well suited for managing and removing the heat that is generated by the LEDs and the underlying electrical circuitry. It is also expensive and not well suited for efficient manufacturing. 
     Another challenge with utilizing LEDs in large arrays is maintaining uniformity of color in the large numbers of LEDs. The color balance and spectra of the LEDs is limited by the phosphorescence. For example, white LEDs are often actually blue LEDs with a complementary phosphor dot on the front of the LED. Depending upon manufacturing precision (and thus, related manufacturing costs), actual colors may vary from, for example, slightly blue to slightly pink. Understandably, reducing or compensating for such variability increases cost and complexity significantly as the number of LEDs increases in larger display configurations and environments. 
     The color and the output of each LED also depend fairly sensitively on temperature. The difficulties in providing proper thermal management capability can readily lead to temperature variations across the distributed array of LED light sources. Since the color qualities of LED light sources are sensitively dependent upon their operating temperatures, such non-uniformities lead to unacceptable variations in color from one portion of the display to another. 
     Additionally, it would be highly desirable to provide an LED light solution for large displays that is adaptable and compliant with existing overall CCFL-based display system configurations and form factors, so that the largest number of components (e.g., LCD screens, color diffusers, filters, housings, and so forth) can continue to be utilized without the need for major redesigns and production modifications. 
     As a result, prior efforts to replace CCFL light sources with LEDs in commercial consumer applications have largely failed to move beyond the prototype stage. The complexities, manufacturing costs, bulkiness, very heavy weights, color non-uniformities, thermal management challenges, and so forth, have simply combined in such a way as to leave experts in the technology convinced that they must yet await the development of even significantly brighter, more uniform, and less expensive LEDs. 
     Consumers expect and demand an excellent, consistent, and affordable consumer experience. Prior attempts to utilize LEDs in large displays have thus not solved the problem of building displays that are light yet rigid, thin, easy and inexpensive to manufacture, uniform in color, low in cost, and that also provide the excellent overall high quality user experience that customers demand and expect. 
     Thus, a need still remains for an improved system for a large LED backlight. In view of the ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace, it is critical that answers be found for these problems. Additionally, the need to reduce costs, improve efficiencies and performance, and meet competitive pressures, adds an even greater urgency to the critical necessity for finding answers to these problems. 
     Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art. 
     SUMMARY 
     The present invention provides a display system with a distributed LED backlight including: providing a plurality of tile LED light sources, each tile LED light source having a tile and a plurality of similar LED light sources on each tile connected for emitting light therefrom; orienting the plurality of tile LED light sources for illuminating a display from the back of the display; and integrating the plurality of tile LED light sources into a thermally and mechanically structurally integrated distributed LED tile matrix backlight light source. 
     Certain embodiments of the invention have other aspects in addition to or in place of those mentioned above. The aspects will become apparent to those skilled in the art from a reading of the following detailed description when taken with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a display system in accordance with an embodiment of the invention; 
         FIG. 2  is an exploded, isometric view of major components of the display system of  FIG. 1 ; 
         FIG. 3  is a fragmentary cross-sectional view of a display system embodiment similar to the embodiment shown in  FIG. 1 ; 
         FIG. 4  is a larger isometric view of the backlight unit shown in  FIG. 2 ; 
         FIG. 5  is an enlarged fragmentary isometric view of a portion of the backlight unit shown in  FIG. 4 ; 
         FIG. 6  is a top plane view of one of the tile bars in the backlight unit shown in  FIG. 4 ; 
         FIG. 7  is a side view of the tile bar shown in  FIG. 6 ; 
         FIG. 8A  is an enlarged top view of the right end of the tile bar shown in  FIG. 6 ; 
         FIG. 8B  is a cross-sectional view of the tile bar shown in  FIG. 6 , taken along line  8 B- 8 B in  FIG. 8A ; 
         FIG. 9A  is a side view of an embodiment of the invention showing overlapping tiles having drop-and-slide hooks; 
         FIG. 9B  is an isometric view of the embodiment of  FIG. 9A ; 
         FIG. 9C  is an isometric fragmentary view of two rows of the overlapping tiles of  FIG. 9A  assembled onto an array tray; 
         FIG. 9D  is an isometric view of another embodiment having overlapping tiles; 
         FIG. 9E  is a side view of additional overlapping tiles connected according to the embodiment of  FIG. 9D ; 
         FIG. 9F  is a side view of an embodiment in which overlapping tiles overlap by being tilted; 
         FIG. 9G  shows a top view of an embodiment with staggered, overlapping tiles arranged to fill a regular geometric space; 
         FIG. 9H  is a top perspective view of the several tile types shown in the embodiment of  FIG. 9G ; 
         FIG. 10A  is a fragmentary isometric view of an embodiment having snap-together tiles that are snapped together into rows; 
         FIG. 10B  is an inverted detail view of the snap-together system for the tiles shown in  FIG. 10A ; 
         FIG. 10C  is a fragmentary isometric view of an array tray having slots therein for receiving rows of the snap-together tiles of  FIG. 10A ; 
         FIG. 11A  is an isometric view of an embodiment having tiles configured with side bends; 
         FIG. 11B  is an inverted fragmentary view of tiles like those in  FIG. 11A , aligned for attachment to one another; 
         FIG. 11C  is a fragmentary isometric view of an array tray receiving rows of the assembled tiles depicted in  FIG. 11A ; 
         FIG. 12A  is an end view of an embodiment having tiles attached in rows to rails; 
         FIG. 12B  is a fragmentary isometric view of an open frame to which the rails shown in  FIG. 12A  are attached in overlapping fashion; 
         FIG. 13A  is an end view of another embodiment having tiles attached in rows to rails; 
         FIG. 13B  is a fragmentary isometric view of a portion of the embodiment of  FIG. 13A ; 
         FIG. 13C  is a fragmentary isometric view of an array tray with rows of the embodiment of  FIGS. 13A and 13B  attached thereon; 
         FIG. 14A  is an end view of an embodiment in which tiles have tile arms bent in a “U” shape around the sides of a T-rail; 
         FIG. 14B  is a fragmentary isometric view of a portion of the embodiment of  FIG. 14A ; 
         FIG. 14C  is an inverted view of the portion of the embodiment shown in  FIG. 14B ; 
         FIG. 14D  is a fragmentary isometric view of rows of the embodiment shown in  FIG. 14B  attached to an open frame array tray; 
         FIG. 14E  is a bottom isometric view of the corner of the structure illustrated in  FIG. 14D ; 
         FIG. 14F  is a top view of an array tray with two of the  FIG. 14B  rows mounted thereon; 
         FIG. 15A  is a fragmentary isometric view of a snap-in rail embodiment that does not require separate fasteners to attach tiles thereto; 
         FIG. 15B  is a fragmentary isometric view of an array tray with the snap-in rails of  FIG. 15A  attached thereon; 
         FIG. 16A  is an end view of an embodiment in which tiles are held on a rail by a lip; 
         FIG. 16B  is a fragmentary isometric view of rails of the embodiment of  FIG. 16A  attached to an array tray; 
         FIG. 17A  is a fragmentary isometric view of an embodiment having a drop-and-slide configuration; 
         FIG. 17B  is a cross-sectional side view of another embodiment having another drop-and-slide configuration; 
         FIG. 18A  is an end view of an embodiment in which tiles in a rail are engaged along one edge in a retaining channel and along the opposite edge by a spring retainer; 
         FIG. 18B  is a fragmentary isometric view of the structure of  FIG. 18A ; 
         FIG. 18C  is a view similar to that of  FIG. 18B  rotated clockwise approximately 90 degrees; 
         FIG. 19A  is an isometric view of an embodiment in which tiles are attached directly to an array tray for additional combined structural strength and integrity; 
         FIG. 19B  is an enlarged cross-sectional view of a portion of the embodiment of  FIG. 19A , taken generally on line  19 B- 19 B therein; 
         FIG. 20A  is a top view of an embodiment in which tiles are structurally attached to a diffuser; 
         FIG. 20B  is a cross-sectional view of the structure of  FIG. 20A  taken on line  20 B- 20 B in  FIG. 20A ; 
         FIG. 21A  is an isometric view of an embodiment adapted for inclusion in a sandwich type of structure; 
         FIG. 21B  is a cross-sectional view of the structure illustrated in  FIG. 21A , taken on line  21 B- 21 B in  FIG. 21A , and in which the tile is sandwiched between an upper plate and a lower plate; 
         FIG. 22A  is an end view of an embodiment having an extruded tray with “T” cross bars on the top surface; 
         FIG. 22B  is an isometric view of a portion of the embodiment of  FIG. 22A  with the addition of stops on the ends thereof; 
         FIG. 22C  is a figurative top view of an alternative configuration for holding tiles in place on the extruded tray shown in  FIGS. 22A and 22B ; 
         FIG. 23  is an end view of an embodiment in which the tiles are their own supporting structure, and interlock to form a structurally integrated matrix; 
         FIG. 24A  is an isometric view of another embodiment in which the tiles are self-supporting; 
         FIG. 24B  is a side view of an embodiment similar to the embodiment of  FIG. 24A ; 
         FIG. 24C  is a side view of another embodiment similar to the embodiments of  FIGS. 24A and 24B ; 
         FIG. 25A  is an isometric view of an embodiment in which interlockable tiles fit together, structurally join, and interlock to form a structurally integrated, rigid, interlocked, three-dimensional tile matrix; 
         FIG. 25B  is a fragmentary top view of a frame in which the tiles shown in  FIG. 25A  have been assembled in interlocked matrix form; 
         FIG. 25C  is a partially exploded, fragmentary, isometric view of a display utilizing the structure of  FIG. 25B , in which tiles have been press-fit together to form a three-dimensional structural plate and then incorporated into a frame; 
         FIG. 25D  is a rear isometric view of the display of  FIG. 25C  attached by a pivot to a support arm stand assembly; 
         FIG. 26  is a fragmentary side cross-sectional view of an embodiment in which an edge reflector provides LED edge lighting; 
         FIG. 27A  is a fragmentary isometric exploded view of an embodiment in which an additional LED light bank provides LED edge lighting; 
         FIG. 27B  is a fragmentary side cross-sectional view of the structure of  FIG. 27A  assembled into a display; and 
         FIG. 28  is a flow chart of a display system with a distributed LED backlight in an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The following embodiments are described in sufficient detail to enable those skilled in the art to make and use the invention. It is to be understood that other embodiments would be evident based on the present disclosure, and that system, process, or mechanical changes may be made without departing from the scope of the present invention. 
     In the following description, numerous specific details are given to provide a thorough understanding of the invention. However, it will be apparent that the invention may be practiced without these specific details. In order to avoid obscuring the present invention, some well-known circuits, system configurations, and process steps are not disclosed in detail. 
     Similarly, the drawings showing embodiments of the system are semi-diagrammatic and not to scale and, particularly, some of the dimensions are for the clarity of presentation and are exaggerated in the drawing FIGs. Likewise, although the views in the drawings for ease of description generally show similar orientations, this depiction in the FIGs. is arbitrary for the most part. Generally, the invention can be considered, understood, and operated in any orientation. 
     In addition, where multiple embodiments are disclosed and described having some features in common, for clarity and ease of illustration, description, and comprehension thereof, similar and like features one to another will ordinarily be described with like reference numerals. 
     For expository purposes, terms, such as “above”, “below”, “bottom”, “top”, “side” (as in “sidewall”), “higher”, “lower”, “upper”, “over”, and “under”, are defined with respect to the back of the display device except where the context indicates a different sense. The term “on” means that there is direct contact among elements. 
     The term “system” as used herein refers to and is defined as the method and as the apparatus of the present invention in accordance with the context in which the term is used. 
     With respect to the use of light-emitting diodes (“LEDs”) rather than cold cathode fluorescent lights (“CCFLs”), an initial concern is thermal management. Normally, LEDs are mounted on a conventional printed circuit board (“PCB”). PCB configurations are convenient, easily configurable, and economical, but they have bad thermal properties because they do not conduct heat very well, and they exhibit mismatches in coefficient of thermal expansion (“CTE”) factors, causing reliability issues and making them unsuitable for large array LED configurations. Metallic substrates can provide excellent thermal performance, equalizing temperatures and conducting heat rapidly away from the LEDs. However, due to the cost, complexity, and difficulty of solving the problem of building large such arrays and of forming circuitry thereon, conductive metallic substrates have not been employed for large LED arrays. 
     One possible solution for using a PCB substrate is to bond it tightly to a thermally conductive layer, such as by attaching a thermally conductive graphite layer to the PCB substrate with thermally conductive (e.g., copper (“Cu”)) rivets. However, when scaled up to large displays (e.g., displays larger than conventional 20-inch computer monitors), the size and complexity of those displays (containing, for example, over 1000 LEDs) become unwieldy and uneconomical. 
     As explained herein, the present invention solves these problems by providing a display system that combines and utilizes a number of tile LED light sources. As used herein, the terms “tile” and “tile LED light source” are defined, according to the context in which used, to mean an assembly, formed integrally on a thermally conductive substrate, with at least two similar or substantially matching LED light sources physically mounted and electrically connected thereon and configured for emitting light therefrom, and with fewer than the total number of LED light sources utilized by the display system into which the tile is incorporated. When used with the term “tile”, the term “thermally conductive” is defined to mean having thermal conduction properties comparable to or better than those of metal. 
     In one embodiment, each tile is formed of a metallic substrate with eight similar or matching LED light sources thereon, each LED light source emitting visible white light. Various display system backlight configurations are then described having a variety of optimizations for attaining co-planarity of the tiles, uniform heat management, weight minimization, efficient manufacturability, economical serviceability, stiffness in various directions, performance efficiency, reduced number of components, efficient assembly operations, optimized assembly geometries, reduced complexity, torsional rigidity, reduced thickness, optimized thermal mechanical outcomes, efficiencies in functional dependencies, creation and maximization of heat exchange surface area for higher massflow and lower velocity air convection (either natural or forced), and so forth, according to the sizes and application environments in which particular such configurations and solutions may be employed. 
     Referring now to  FIG. 1 , therein is shown a perspective view of a display system  100  having a display assembly  102  supported in a frame  104 . In turn; the frame  104  is supported on a stand  106 . The display system  100  has a distributed LED backlight (not shown, but see the backlight unit  220  in  FIG. 2 ). As used herein, the term “backlight” is defined to mean a form of illumination that provides light for a display that illuminates the display from the back of the display. This definition means that the light is presented to the side of the display opposite the side of the display that is viewed, such that the light is shining through the display toward the viewer rather than reflecting toward the viewer from the front side of the display. As used herein, the term “distributed” is defined to mean that the LED light sources of the LED backlight are positioned across and within the display area of the display assembly  102 , and not just around the periphery thereof adjacent the front bezel (e.g., the front bezel  202  in  FIG. 2 ). 
     Referring now to  FIG. 2 , therein is shown an exploded, isometric view of the majority of the major components of the display assembly  102 . The frame  104  ( FIG. 1 ) includes a front bezel  202 , a panel frame  204 , and panel side rails  206 . 
     The display assembly  102  also includes a liquid crystal display (“LCD”) sub-assembly  208  that connects to LCD circuitry  210 . In one embodiment, the LCD sub-assembly  208  utilizes thin film transistor (“TFT”) technology to form a TFT LCD display, as is known in the art. 
     Beneath the LCD sub-assembly  208  are backlight diffuser sheets  212 , beneath which is a reflector  214  having holes  216  therein that receive LEDs  218  on a backlight unit  220 . The reflector  214  is thus positioned around the LEDs  218 . The LEDs  218  are oriented forwardly toward the LCD sub-assembly  208  for illuminating the display assembly  102  from the back of the display. 
     The backlight unit  220  is physically and thermally attached to an array tray  222 . A heat spreader  224 , such as a graphite sheet, is attached to the back of the array tray  222  opposite the backlight unit  220  to conduct heat rapidly away therefrom and to equalize temperatures throughout the backlight unit  220 . By connecting directly to the array tray  222  to which the backlight unit  220  is physically and thermally attached, the heat spreader  224  thermally integrates therewith, including with the tiles (see the tiles  404  in  FIG. 4 ) in the backlight unit  220 . 
     Beneath the heat spreader  224  are two LED driver circuit boards  226 , one on either side of the display assembly  102 . Beneath one of the LED driver circuit boards  226 , toward one side of the display assembly  102 , is an LCD controller power control board  228  that is protected by an LCD controller shield  230  therebeneath. An LED power supply  232  is attached beneath the other LED driver circuit board  226  on the other side of the display assembly  102 , opposite the LCD controller power control board  228 . An LED power supply insulator  234  protects the LED power supply  232 . 
     Referring now to  FIG. 3 , therein is shown a fragmentary cross-sectional view of an embodiment of a display system  100 ′ similar to the display system  100  ( FIG. 1 ). To aid in producing uniform illumination of the LCD sub-assembly  208 , the backlight unit  220  is spaced from the LCD sub-assembly  208  by spacers  302 . 
     Referring now to  FIG. 4 , therein is shown a larger isometric view of the backlight unit  220 . The backlight unit  220  is formed of a series of tile bars  402  arranged adjacent and parallel to each other. Each tile bar  402  is formed of a number of tiles  404  attached in a series on top of a tile bar rail  406 . 
     Referring now to  FIG. 5 , therein is shown an enlarged fragmentary isometric view of a portion of the backlight unit  220  assembled onto the array tray  222  and attached thereto by screws  502 . The tile bars  402  are arranged in alternating positions (as also shown in  FIG. 4 ), with one end of each tile bar  402  being provided with an electrical connector  504 . 
     The electrical connectors  504  are connected directly to the tiles  404  thereadjacent. Electrical power for the remaining tiles  404 , in a respective tile bar  402 , is provided by wire bonds  506  that electrically connect adjacent tiles by jumping from tile to tile along the respective tile bars  402  to connect through-conductors (not shown) that are formed in each tile  404 . 
     The tiles  404  themselves are individual structures that physically and electrically support and interconnect the LEDs  218  the same surface of the tile  404 . Further, as indicated, in one embodiment, as shown, the tiles  404  also provide electrical continuity for connecting to and providing power to adjacent tiles, such as by means of the wire bonds  506 . 
     Also, the LEDs  218 , which in one embodiment, as illustrated, are provided eight per tile  404 , are actually LED clusters in various embodiments. In such clusters, each of the LEDs  218  is actually a cluster of four discreet LEDs, one blue LED, one red LED, and two green LEDs. Each such cluster is encapsulated, for example, with silicone, and the individual discrete LEDs therein are then electrically driven to emit respective intensities that combine to provide white light from each such LED  218  cluster. 
     In other embodiments, other LED configurations may be utilized. For example, white only LEDs may be employed. 
     To provide for excellent thermal conductivity and performance, the tiles  404  are formed of aluminum (“Al”) substrates on which there is a thin thermally conductive but electrically insulating layer. On the top of this electrically insulating layer, the LEDs and associated circuitry are formed, for example, by conventional semiconductor fabrication processes. This beneficially provides for excellent thermal performance, and enhances heat conduction into the support structures to which the tiles  404  are attached, such as the tile bars  402 , and so forth. As used herein, therefore, the term “thermally structurally integrated” is defined to mean that the tiles are thermally conductive (not insulating) and actively contribute to their own heat removal in cooperation and combination with the physical support structure to which they are attached, such that the combination of the tiles and such support structure attains heat flow thereamong that is greater than would be attained using a tile having a substrate formed of a material having a lower heat conductivity than metal. 
     Additionally, by forming the tiles  404  in this manner with a metallic substrate, not only is excellent thermal performance achieved, but the tiles also have superior formability and machineability such that the tiles can be shaped, if desired, into complex configurations, as illustrated further herein. 
     Importantly, the tiles  404  are strong enough to become active structural elements, i.e., mechanical building blocks, that can be mechanically structurally integrated into integrated LED tile matrices rather than simply riding passively on an external supporting structure. That is, by integrating into and becoming part of their own structural support matrix, external support requirements can be substantially reduced, resulting in significant savings in weight, cost, display thickness, and so forth. As used herein, therefore, the term “mechanically structurally integrated” is defined to mean that the tiles actively contribute to their own physical support, and when attached to an additional physical support structure, that the tiles function in cooperation and combination therewith such that the combination of the tiles and such support structure is stronger and more rigid than the support structure alone. As used herein, the term “passively” is accordingly defined to mean: attaching tiles in a manner such that structural assistance and physical support is not effectively provided by the tiles. 
     According to the present invention and the particular embodiments under consideration, the tiles may be joined to one another in a self-supporting mechanically structurally integrated structure. Alternatively, the tiles may be mechanically structurally integrated with an additional support structure such that the additional support structure may be lighter in weight, thickness, and so forth, and less robust than would be necessary to support itself and the tiles were the tiles riding passively and not assisting in the structural support thereof. In other words, because of the mechanical structural integration with the tiles, such an additional support structure may be designed so that it is not strong enough to support itself and self-maintain its profile when burdened passively with the weight of a number of tile LED light sources. This is possible because the tile LED light sources are then actively combined and structurally integrated with and assist the additional support structure to help in providing support as well, so that together the integrated structure has sufficient strength and integrity to support the total combined weight. 
     It will be further understood based upon this disclosure that the tiles, as a result of their configurations, and where disclosed, their combinations with additional support structure, according to the particular embodiments, are integrated into three-dimensionally mechanically structurally integrated backlight light sources. This means that the integrated backlight light source structures provide enhanced strength, integrity, and rigidity in all three dimensions, and not just in a two dimensional planar sense. 
     Referring now to  FIG. 6 , therein is shown a top plane view of a tile bar  402 . 
     Referring now to  FIG. 7 , therein is shown a side view of the tile bar  402  shown in  FIG. 6 . 
     Referring now to  FIG. 8A , therein is shown an enlarged top view of the right end of the tile bar  402  shown in  FIG. 6 . 
     Referring now to  FIG. 8B , therein is shown a cross-sectional view of the tile bar  402  taken on line  8 B- 8 B in  FIG. 8A . A thermally conductive adhesive  802  adheres the tile  404  structurally to the tile bar rail  406  of the tile bar  402  such that the combined tile  404  and tile bar rail  406  are united into a unit that is stronger and more rigid than either the tile  404  or the tile bar rail  406  alone. 
     Referring now to  FIG. 9A , therein is shown a side view of an embodiment  900  of overlapping tiles  902  provided with drop-and-slide hooks  904 . Adjacent overlapping tiles  902  may be attached to each other by screws  906 , or by other appropriate attachments selected, for example, from rivets, clinch rivets, spot welds, line welds, screws, and a combination thereof. 
     To preserve co-planarity of the overlapping tiles  902 , a drop jog  908  is provided on one end of each of the overlapping tiles  902 . The drop jog  908  forms a jogged end  910  at the tile end, dropped sufficiently to slip underneath the tile next adjacent thereto while keeping the overlapping tiles  902  themselves flat and co-planar. 
     Referring now to  FIG. 9B , therein is shown an isometric view of the embodiment  900 . In this embodiment, alignment holes  912  are provided through each end of the overlapping tiles  902 . The alignment holes  912  provide a convenient mechanism for aligning the overlapping tiles  902  for assembly into rows, as illustrated. Such assembly can be easily accomplished, for example, by locating the alignment holes  912  onto pre-positioned pins (not shown) to hold the overlapping tiles  902  in position while the screws  906  are tightened. By this means, the tiles can be quickly and accurately aligned for assembly to each other. 
     It will also be readily understood by one of ordinary skill in the art, based upon the teachings in the present disclosure, that other suitable fasteners and/or attachments may be employed, as desired or appropriate, in place of the screws  906 . Such attachments would include, for example, rivets, clinch rivets, spot welds, line welds, and the like, and may be utilized as appropriate with any of the tile configurations disclosed herein. 
     Referring now to  FIG. 9C , therein is shown an isometric fragmentary view of an assembly  914  in which two rows  916  of the overlapping tiles  902  have been assembled onto an array tray  918 . It will be understood, of course, that in a finished display, the array tray  918  would have many more rows  916  assembled thereonto. Only two rows  916  are illustrated in order to better reveal details of the assembly  914 , including the array tray  918  that is beneath the rows  916 . 
     Similarly, in other embodiments disclosed and illustrated herein, only a few tile rows will generally be shown so that the details of the array trays to which they are attached, in several of the embodiments, can be better shown. 
     The array tray  918  is provided with slots  920  that are located to receive the drop-and-slide hooks  904  of the overlapping tiles  902 . The assembly  914  is then easily and quickly assembled by dropping the drop-and-slide hooks  904  through the slots  920  and sliding the rows  916  to cause the drop-and-slide hooks  904  to engage underneath the ends of the slots  920 , thereby attaching the overlapping tiles  902  to the array tray  918 . 
     To increase the strength, integrity, and rigidity of the array tray  918 , one or more stiffeners  922  may be provided, for example, on the underside of the array tray  918  opposite the rows  916  that are on the top of the array tray  918 . This further assists in maintaining the flatness of the array of the tiles  902 . 
     Referring now to  FIG. 9D , therein is shown an isometric view of an embodiment  924  having overlapping tiles  926 . In the embodiment  924 , each of the overlapping tiles  926  has a jog  928  located intermediately thereon that forms a foot  930  that, by comparison, is proportionately significantly larger than the jogged ends  910  ( FIG. 9A ) of embodiment  900  ( FIG. 9A ). Also, rather than being arranged in rows, such as the rows  916  ( FIG. 9C ), the overlapping tiles  926  are staggered both longitudinally and laterally, and are connected to each other by fasteners  932 . 
     The staggered configuration of the overlapping tiles  926  and the larger sizes of the feet  930  provide sufficient structural and physical strength and integrity for the overlapping tiles  926  to be self-supporting without the need for an underlying array tray. The significant overlap and staggered configuration also significantly improve thermal conduction between and among the overlapping tiles  926 , aiding temperature uniformity and heat removal for superior performance. 
     Referring now to  FIG. 9E , therein is shown a side view of additional overlapping tiles  926  connected according to the embodiment  924  of  FIG. 9D . 
     Referring now to  FIG. 9F , therein is shown a side view of an embodiment  934  in which overlapping tiles  936  overlap by being tilted. When the overlapping tiles  936  overlap by tilt, as illustrated, it is possible that the LEDs  218  may not emit light in the desired direction, since the light may tend to emit perpendicularly to the surfaces of the individual overlapping tiles  936 . In that case, it may be desirable to fabricate the LEDs  218  so that they emit more in the desired direction, such as at an appropriate angle to the top surfaces of the overlapping tiles  936 . 
     With respect to the embodiment  934 , the tilted and overlapping tiles  936  form a configuration, for example, somewhat like roof tiles, and thus average out overall to a flat surface. This illustrates that, depending upon the configuration, the overlapping tiles  936  do not necessarily need to be orthogonal with respect to the environment, nor do the LEDs  218  need to be orthogonal. In such a case, when tilted in this fashion rather than planar, the LEDs  218  can then be fabricated, as indicated, to direct the light as desired. That is, the LEDs  218  can be grown at a compensating angle, for example. Such an overlapping or tiled arrangement has several advantages, for example, providing improved structural strength, integrity, and rigidity, and improved heat transfer and heat management characteristics. 
     Referring now to  FIGS. 9G and 9H , therein is shown an embodiment  938  illustrating, for example, how staggered tiles, such as the overlapping tiles  926  in  FIG. 9D , can be arranged to fill a regular geometric space, such as a rectangle, having straight edges. In this embodiment, the majority of the tiles are overlapping tiles  940 , for example similar to the overlapping tiles  926 , arranged in a herringbone pattern. Then, to accommodate the staggered configuration, half tiles  942  are provided on the ends of alternating rows. The half tiles  942  are substantially the same as the overlapping tiles  940  but only approximately half as wide. Finally, to accommodate each foot  944  of the overlapping tiles  940  and  942  along the top edge perimeter  946 , cap tiles  948  are provided for positioning over the feet  944 . In one embodiment, the cap tiles  948  are substantially the same as the overlapping tiles  940  except that the cap tiles  948  do not have feet  944 . The embodiment  938  thus provides the advantages of a staggered overlap to enhance thermal conduction and mechanical connection of the tiles in all directions, while also fitting snugly into a space that has straight edges. 
     Referring now to  FIG. 10A , therein is shown a fragmentary isometric view of an embodiment  1000  in which snap-together tiles  1002  are snapped together into rows. In this embodiment, the snaps that hold the snap-together tiles  1002  together are flexures  1004 , at one end of each snap-together tile  1002 , that are springably received in matching slots  1006  at the opposite ends of the snap-together tiles  1002 . In particular, each flexure  1004  has a detent  1008  on the end thereof that is springably received in its matching slot  1006  on the adjacent snap-together tile  1002 . 
     Electrical connections and electrical continuity may be provided between the snap-together tiles  1002  by any suitable means, such as an electrically conductive tape  1010 , edge connectors (not shown) flex interconnects (not shown), the optional use of pad connectors (not shown), and so forth. 
     Advantageously, it will now be understood by those of skill in the art, based upon the teachings herein, that electrical connections between and among the tiles of the various other embodiments disclosed herein may likewise be readily achieved and provided by conductive tape, edge connectors, and so forth, as disclosed herein and as desired and appropriate for the particular configurations and embodiments at hand. 
     Referring now to  FIG. 10B , therein is shown an inverted detail view of the flexure  1004  and slot  1006  snap-together system for the snap-together tiles  1002 . 
     Referring now to  FIG. 10C , therein is shown a fragmentary isometric view of an array tray  1012  having slots  1014  therein for receiving rows  1016  of the snap-together tiles  1002 . The rows  1016  of the snap-together tiles  1002  can be secured to the array tray  1012 , for example, by screws  1018  that pass through the snap-together tiles  1002  to engage in screw holes  1020  in the array tray  1012 . 
     Referring now to  FIG. 11A , therein is shown an isometric view of an embodiment  1100  having tiles  1102  that are configured as side bend tiles. In this embodiment, the tiles  1102  have side bends  1104  along, for example, the longitudinal sides thereof, extending downwardly from the major top surfaces of the tiles  1102 , and providing increased rigidity for the tiles  1102 . 
     Each side bend  1104  has a tab  1106  at one end. Holes  1108  are formed at each end of the side bends  1104 . The side bends  1104  in this embodiment are split and slightly staggered inwardly and outwardly, from one end to the other, so that they can overlap when the tiles  1102  are assembled to each other in series. 
     When the tiles  1102  are assembled in series into rows, the holes  1108  in the side bends  1104  line up so that the tiles  1102  can be secured to each other by screws  1110 . This results in a strong row of assembled tiles  1102  having increased rigidity. With this configuration, the tiles  1102  can also be self-aligning. 
     Referring now to  FIG. 11B , therein is shown an inverted fragment of tiles like the tiles  1102  shown in  FIG. 11A , aligned for serial attachment to one another and showing in greater detail the alignment of the holes  1108 . 
     Referring now to  FIG. 11C , therein is shown a fragmentary isometric view of an array tray  1112  receiving rows  1114  of the assembled tiles  1102 . The array tray  1112  has an extruded corrugated configuration that provides additional strength, integrity, and rigidity. Depending upon the particular dimensions that are provided, the array tray  1112  can also provide self-alignment for the tiles  1102 . The rows  1114  of the tiles  1102  may be secured to the array tray  1112  by any suitable means, such as screws  1116  passing through the tiles  1102  into holes  1118  in the array tray  1112 . 
     Referring now to  FIG. 12A , therein is shown an end view of an embodiment  1200  having tiles  1202  that are not attached directly to one another, but instead are attached in groups to rails  1204 . (A single tile  1202  and single rail  1204  are shown in  FIG. 12A .) The rails  1204  then assemble and support the groups of the tiles  1202  into row structures formed thus with increased rigidity. In one embodiment, the rails  1204  are sheet metal rails having a jog  1206  allowing the rails  1204  to be assembled to each other in overlapping fashion (see  FIG. 12B ). 
     For ease and simplicity of assembly, the rails  1204  have a return  1208  along one side that forms a pocket  1210 . The tiles  1202  are then captured along one tile edge in the pocket  1210 , and then securely attached to the rail  1204  with only a single tile screw  1212 . That is, the return  1208  creates a “V” shape that forms the pocket  1210  that easily captures a tile therein, providing for rapid and secure assembly with the requirement of only the single tile screw  1212 . 
     Referring now to  FIG. 12B , therein is shown a fragmentary isometric view of an open frame  1214  to which the overlapping rails  1204  are attached with rail screws  1216 . Unlike the array trays in previous embodiments of the present invention, the overlapping sheet metal rails  1204  provide sufficient increased rigidity that an entire tray is not required. Instead, weight and material savings can be realized by using an open frame such as the open frame  1214 . 
     Referring now to  FIG. 13A , therein is shown an end view of an embodiment  1300  also having tiles attached in rows to rails. In embodiment  1300 , tiles  1302  are mounted longitudinally in a row (see  FIG. 13B ) on a rail  1304 . The rail  1304  may be extruded, and has a pocket  1306  formed along one side by a return  1308  to capture an edge of the tile  1302  therein. The bottom of the pocket  1306  includes a small radius clearance  1310  that is undercut slightly below the surface of the rail  1304  on which the tile  1302  is mounted. 
     The small radius clearance  1310 , thus located under the edge of the tile  1302  that is captured in the pocket  1306 , provides a thickness tolerance for the tiles  1302 , particularly where the pocket  1306  is dimensioned close to the thickness of the tiles  1302 . In this way, slight variations in tile thicknesses are accommodated by the small radius clearance  1310  beneath the pocket  1306 , allowing thicker tiles to fit and bend slightly into the small radius clearance  1310 . 
     Opposite the pocket  1306 , on the other side of the rail  1304 , is a hole  1312  in the rail  1304 . The hole  1312  aligns with a matching hole  1314  in the tile  1302 , so that a clip  1316 , such as a U-shaped spring steel clip, formed with protrusions  1318 , can capture and retain the tiles  1302  on the rails  1304  by clipping the protrusions  1318  into the holes  1312  and  1314 . Consequently, the small radius clearance  1310  effectively provides for preloading the tile edge therein to provide a thickness tolerance for the tiles  1302 . The clips  1316  provide for rapid and easy assembly of the tiles  1302  onto the rails  1304 , typically faster than would be required to align and assemble with screws. This also results in the formation of rows with increased rigidity. 
     Referring now to  FIG. 13B , therein is shown a fragmentary isometric view of a portion of the embodiment  1300 . 
     Referring now to  FIG. 13C , therein is shown a fragmentary isometric view of an array tray  1320  on which rows  1322  of the embodiment  1300  are attached. Holes  1324  provide clip clearance for the clips  1316  in the array tray  1320 . The array tray  1320  provides additional stiffness for the embodiment  1300 , particularly in the direction transverse thereto. This further assists in maintaining the flatness of the array of the tiles  1302 . 
     Referring now to  FIG. 14A ; therein is shown an end view of an embodiment  1400  in which tiles  1402  have tile arms  1404  along the sides thereof that are bent in a “U” shape around the sides of a T-rail  1406  to engage the T-rail  1406  and attach themselves thereto. Each T-rail  1406  then serves as a substrate that defines a row of the tiles  1402 , which are affixed in a longitudinal series thereon, forming rows with increased rigidity. 
     Referring now to  FIG. 14B , therein is shown a fragmentary isometric view of a portion of the embodiment  1400 . 
     Referring now to  FIG. 14C , therein is shown an inverted view of the portion of the embodiment  1400  shown in  FIG. 14B . Tips  1408  of spring fingers  1410 , extending longitudinally from the tile arms  1404  on the underside of the T-rail  1406 , are received and held in corresponding pockets  1412  in the T-rail  1406  to secure the tiles  1402  in position on the T-rail  1406 . 
     The embodiment  1400  thus provides increased rigidity due to the increased strength and integrity provided by the T-rails  1406  and the structural stiffening afforded by the bent-around tile arms  1404 . This further assists in maintaining the flatness of the array of the tiles  1402 . The T-rails  1406  may be economically and efficiently fabricated, for example as extrusions, and the pockets  1412  may then be formed therein by any suitable conventional process. 
     Concerning the spring fingers  1410 , they not only conveniently locate the respective tiles  1402  in the proper locations on the T-rails  1406 , but the spring fingers  1410  additionally pressure the tiles  1402  forward and against the T-rails  1406  for improving convective area and heat exchange thermal contact therebetween. 
     Referring now to  FIG. 14D , therein is shown a fragmentary isometric view of rows  1414  of the embodiment  1400  attached to an array tray  1416  by screws  1418 . The array tray  1416 , for this embodiment  1400 , is an open frame having cut outs  1420  therein that define cross members  1422 . The cut outs  1420  advantageously reduce the weight of the array tray  1416 . While the cut outs  1420  also reduce the overall strength of the array tray  1416 , this is acceptable due to the additional stiffness, strength, integrity, and rigidity provided by the companion T-rails  1406  with the tiles  1402  attached thereon. 
     Referring now to  FIG. 14E , therein is shown a bottom isometric view of the corner of the structure illustrated in  FIG. 14D . The inner edge of the array tray  1416  along the cut outs  1420  is bent over and under the array tray  1416  to form a hem  1424 . The configuration of the hem  1424  is a stiffness-improving feature for the array tray  1416 . This further assists in maintaining the flatness of the array of the tiles  1402 . 
     Referring now to  FIG. 14F , therein is shown a top view of the array tray  1416  with two of the rows  1414  mounted thereon. 
     Referring now to  FIG. 15A , therein is shown a fragmentary isometric view of an embodiment  1500  in which no fasteners are separately required to attach tiles  1502  to a snap-in rail  1504 . Instead, the snap-in rails  1504  in the embodiment  1500  have hooks  1506  placed at intervals therealong slightly longer than the lengths of the tiles  1502 . The snap-in rails  1504  may, for example, be constructed of sheet metal, and the hooks  1506  may be punched up therefrom and formed so that the tiles  1502  can be slipped under the hooks  1506  and captured therein to form rows with increased rigidity. 
     Assembly of the tiles  1502  onto the snap-in rails  1504  is then completed, after hooking the tiles  1502  under the hooks  1506 , by rotating the tiles  1502  downwardly past snap-in retainers  1508  onto the snap-in rail  1504 . The snap-in retainers  1508  are flexures having a beveled detent  1510  thereon just above the upper surface of the snap-in rail  1504  and positioned to project slightly over a tile  1502  when snapped into position and retained at the opposite end by the hook  1506 . The snap-in retainers  1508  may be formed from the material of the snap-in rails  1504 , or may be inserted as a separate spring part, as desired. 
     Each tile  1502  is then snapped into position by pressing the end adjacent the snap-in retainers  1508  downwardly causing the detent  1510  to flex momentarily out of the way and then snap back over the tile  1502  to capture it in place. 
     When the tiles  1502  are thus snapped onto the snap-in rail  1504 , each tile is held in position by a hook  1506  and a snap-in retainer  1508 . The hook  1506  receives and holds one end of the tile  1502 , and the snap-in retainer  1508  forms a spring-snap flexure that receives and holds the opposite end of the tile  1502 . 
     The snap-in rail  1504  may advantageously have sheet metal bends  1512  formed longitudinally along the longitudinal edges thereof to add longitudinal stiffness to the snap-in rails  1504 . Consequently, the snap-in rails  1504  form rows with increased rigidity, part of the increased rigidity resulting from the combination of the stiffness from the tiles  1502  being attached to the snap-in rails  1504 , and part of the increased rigidity being a result of the sheet metal bends  1512  that are formed along the longitudinal edges of the snap-in rails  1504 . This further assists in maintaining the flatness of the array of the tiles  1502 . 
     Referring now to  FIG. 15B , therein is shown a fragmentary isometric view of an array tray  1514  onto which snap-in rails  1504  are attached, for example, by screws  1516 . 
     Referring now to  FIG. 16A , therein is shown an end view of an embodiment  1600  in which tiles  1602  are held securely on a rail  1604  by a lip  1606 , forming rows with increased rigidity. The lips  1606  are formed integrally on the rails  1604 , for example by extrusion of the rails  1604 . Initially in an open position, the lip  1606  is then deformed, for example under the force of a press (not shown), to bend the lip  1606 , such as in the direction of the arrow  1608 , over and onto the tiles  1602  along one longitudinal edge thereof. In this manner, the tiles  1602  are captured and held tightly on the top of the rails  1604  by the lip  1606 . That is, the lips  1606  are deformable onto the edges of the tiles  1602  thereadjacent, retaining the tiles  1602  underneath the lip  1606  by deforming the lip  1606  thereagainst. 
     Referring now to  FIG. 16B , therein is shown a fragmentary isometric view of several rails  1604  of the embodiment  1600  positioned on an array tray  1610 . Each of the rails  1604  may be attached to the array tray  1610  by screws (not shown) inserted through screw holes  1612  in the rails  1604 . 
     Retention of the tiles  1602  by the lip  1606  may be enhanced by holes  1614  formed in the edges of the tiles  1602  in positions that locate the holes  1614  underneath the lip  1606  after it is deformed or bent thereover. The lips  1606  then engage the holes  1614  therebeneath, thereby enhancing retention of the tiles  1602 . In other words, when the lip  1606  is crimped onto the tile  1602 , a little bit of the material from the lip  1606  actually extrudes into the holes  1614 , thereby catching the tile  1602 . Consequently, the tile  1602  can be firmly attached to the rail  1604  without requiring any separate fasteners. 
     Referring now to  FIG. 17A , therein is shown a fragmentary isometric view an embodiment  1700  having a drop-and-slide configuration in which tiles  1702  have slots  1704  therein that match hooks  1706  on a rail  1708 . The hooks  1706  are drop-and-slide hooks such that the tiles  1702  are dropped over the hooks  1706  and receive the hooks  1706  through the slots  1704 . The tiles  1702  are then slid horizontally to slip underneath the hooks  1706  to be engaged and held firmly against the rail  1708 . Upon sliding into position, a spring finger  1710  is then revealed and released against the end of the tile  1702  that moves toward the hooks  1706  as the tiles  1702  is being slid thereunder. The spring finger  1710  then holds the tiles engaged with the hooks  1706  to lock the tiles  1702  on the rail  1708  to form rows with increased rigidity. The tiles  1702  can thus be attached to the rails  1708  without separate fasteners. 
     The combination of the tiles  1702  captured in this fashion on the rail  1708  forms a row with increased rigidity. 
     Similarly, the rails  1708  can be attached to an array tray  1712  without separate fasteners by engaging tabs  1714  formed on and underneath the rails  1708  into clips  1716  on the array tray  1712 . In one embodiment, as shown, the tabs  1714  and the clips  1716  are configured to constitute a drop-and-slide feature, such that the tabs  1714  drop beneath the clips  1716 , below the array tray  1712 , so that the rail  1708  is held snugly against the array tray  1712 . 
     For providing electrical continuity between the tiles  1702 , a ribbon connector  1718  is provided between adjacent tiles  1702 . 
     Referring now to  FIG. 17B , therein is shown a cross-sectional side view of an embodiment  1720  having another drop-and-slide configuration. In this embodiment, a rail  1722  is attached to an array tray  1724 , and the rail  1722  has an end stop  1726  mounted thereon to hold the tiles  1702  engaged with the hooks  1706  to lock the tiles  1702  on the rails  1722 . 
     The embodiment  1720  illustrates additional aspects of the present invention, wherein the versatility of the invention, for example, allows the array tray  1724  to function as well as the external housing for the display, or vice versa. Also shown is a PCB  1728  captured and supported in a stand  1730  beneath the tiles  1702 . Additionally, the hooks  1706  may be configured to provide electrical connections (not shown) to the tiles  1702 . 
     Referring now to  FIG. 18A , therein is shown an end view of an embodiment  1800  in which tiles  1802  are engaged along one edge in a retaining channel  1804  of a rail  1806  on which the tiles  1802  are placed. The rails  1806  may be formed, for example, by extrusion. In one embodiment, the retaining channels  1804  are shaped as overhanging lips formed along one edge of the rail  1806  and extending upwardly and over the top surface of the rail  1806  and over the adjacent edge of each of the tiles  1802  when located thereon. 
     Once the tiles  1802  are in position on the top of the rail  1806  and captured along one edge in the retaining channel  1804 , a retainer spring  1808  is then positioned downwardly against the edges of the tiles  1802  along the edge of the rail  1806  opposite the retaining channel  1804 . The retainer spring  1808  is then secured in position, for example, by screws  1810 . 
     The retainer springs  1808  may be formed of a suitable resilient material, such as spring steel, and function thereby not only to hold the tiles  1802  in place on top of the rails  1806 , but to maintain a downward and lateral pressure on the tiles  1802 . The retainer springs  1808  thus press the tiles  1802  against the rails  1806  for better heat transfer, hold the tiles  1802  in position on the rails  1806  against vibration, and so forth. The retainer springs  1808  also press the tiles  1802  laterally toward the retaining channel  1804  for better attachment to the rails  1806 . 
     Referring now to  FIG. 18B , therein is shown a fragmentary isometric view of the structure in  FIG. 18A . In one embodiment, the retainer springs  1808  have a relief  1812 , or slot, formed between each of the tiles  1802 . The reliefs  1812  provide retainer springs  1808  that are at least partially discontinuous between the tiles  1802 , thereby largely separating the portions of the retainer springs  1808  that contact each of the tiles  1802 . Consequently, each tile effectively has its own retainer spring  1808 , since the spring sections are individualized and separated from each other by the reliefs  1812 . 
     Referring now to  FIG. 18C , therein is shown a view similar to that shown in  FIG. 18B  but rotated clockwise approximately 90 degrees to better show access gaps  1816  that may be formed in one or more corners of the tiles  1802 . The access gap  1816  is akin to a missing corner and, when adjacent the retainer spring  1808 , provides ready access to the tile  1802  for engaging the tile to pry the tile loose from underneath the retainer spring  1808 . This facilitates removing the tile without having to remove the entire retainer spring  1808 . The reliefs  1812  further facilitate such individual tile removal. 
     The combination of the tiles  1802  attached securely to the rails  1806  thus forms rows of the tiles  1802  with increased overall rigidity. Screw holes  1814  in the rails  1806  provide a convenient configuration and means for attaching the rails  1806  to an underlying support structure, such as an array tray (not shown). 
     Advantageously, the embodiment  1800  thus provides for readily, quickly, and efficiently assembling tiles  1802  into rows with a minimum number of fasteners while securely holding the tiles  1802  in position. 
     Referring now to  FIG. 19A , therein is shown an isometric view of an embodiment  1900  in which tiles  1902  are attached directly to an array tray  1904  to give the array tray  1904  sufficient additional combined structural strength and integrity to enable the array tray  1904  to support the tiles  1902  that are attached directly thereon. As used herein, the phrase “to enable it to support” is defined to mean that the array tray  1904  is not strong enough to support the tiles  1902  on its own, and can support the tiles  1902  only by virtue of the additional structural strength and integrity provided by the tiles  1902  themselves, and working in concert with the array tray  1904 . 
     The array tray  1904  may be formed, for example, by forming sheet metal. The sides of the array tray  1904  may include legs  1906  that extend at an angle therefrom to further stiffen and strengthen the array tray  1904  and tile  1902  assembly. This further assists in maintaining the flatness of the array of the tiles  1902 . 
     The legs  1906  may additionally be formed, for example, to reach around and define a PCB area  1908  in which PCBs such as PCBs  1910 , and other electrical/electronic components, may be attached and supported. 
     These components can then all be thermally as well as structurally integrated, such as, for example, by using a thermal grease or other thermally conducting material (not shown) between the tiles  1902  and the array tray  1904 , and similarly providing heat conducting facilities between the PCBs  1910  and the array tray  1904 . Effective heat conduction away therefrom by the array tray  1904  can be facilitated, for example, by forming feet  1912  on the bottom of the legs  1906  of the array tray  1904 . The feet  1912  can then be attached to a suitable frame or body member for removing heat therefrom, as well as supporting the array tray  1904  and assembled components within a display. 
     Referring now to  FIG. 19B , therein is shown an enlarged cross-sectional view of a portion of the embodiment  1900  illustrated in  FIG. 19A , taken generally on line  19 B- 19 B in  FIG. 19A . In this embodiment, the tiles  1902  can be conveniently and efficiently attached to the array tray  1904  by suitable fasteners, such as pairs of rivet fasteners  1914 . In one embodiment, a clinch rivet metal fastener can be used, such as a TOX® fastener (“TOX” is a registered trademark of PRESSOTECHNIK GMBH Corporation, Weingarten, Germany). 
     Referring now to  FIG. 20A , therein is shown a top view of an embodiment  2000  in which tiles  2002  are structurally attached to the underside of a clear or translucent diffuser, such as a diffuser plate  2004 . The tiles can be attached to the diffuser plate  2004  by any suitable means, such as a screw fastener  2006 , thereby reinforcing the diffuser plate  2004  to give it sufficient additional structural strength and integrity to enable it to support the tiles  2002  attached thereon. 
     Referring now to  FIG. 20B , therein is shown a cross-sectional view of the structure of  FIG. 20A  taken on line  20 B- 20 B in  FIG. 20A . 
     Referring now to  FIG. 21A , therein is shown an isometric view of an embodiment  2100  in which a tile  2102  has a screw hole  2104  therethrough, passing from top to bottom, and a notch  2106  in at least one of the sides. The tile  2102  is thereby well adapted for inclusion in a sandwich type of structure. 
     Referring now to  FIG. 21B , therein is shown a cross-sectional view of the structure illustrated in  FIG. 21A , taken on line  21 B- 21 B therein, and in which the tile  2102  is sandwiched between an upper plate  2108  and a lower plate  2110 . A screw  2112  passes through a screw hole  2114  in the upper plate  2108 . The screw hole  2114  is aligned with the screw hole  2104  in the tile  2102 , so that the screw  2112  can pass through the screw holes  2104  and  2114  to engage a nut  2116  that is anchored in the lower plate  2110 . This configuration structurally attaches the tile  2102  between the upper plate  2108  and the lower plate  2110  to give the upper plate  2108  and the lower plate  2110  sufficient additional structural strength and integrity to enable them to support the tiles  2102  attached thereon and therebetween. 
     To align the tiles  2102  on the lower plate  2110 , a half shear  2118  may be provided on the upper surface of the lower plate  2110  to engage the notches  2106  in the tile  2102 . This provides for rapid and accurate assembly, and permits the use of but a single screw  2112  to assemble each tile  2102  accurately and to hold the assembly together. 
     Referring now to  FIG. 22A , therein is shown an end view of an embodiment  2200  in which an extruded tray  2202  has “T” cross bars  2204  formed on and extending over the top surface thereof. The “T” cross bars  2204  capture tiles  2206  in slots  2208  that are provided beneath the caps of the “T” cross bars  2204  above the top surface of the extruded tray  2202 . The tiles  2206  are thus structurally captured directly in the slots  2208  in the extruded tray  2202  to give the extruded tray  2202  sufficient additional structural strength and integrity to enable it to support the tiles  2206  that are attached thereon. 
     Referring now to  FIG. 22B , therein is shown an isometric view of a portion of the embodiment  2200  with the addition of stops  2210  on the ends thereof. The stops  2210 , which are located at or across the ends of the slots  2208 , then capture the tiles  2206  in place and hold them in place. 
     Referring now to  FIG. 22C , therein is shown a somewhat figurative top view of an alternative configuration for holding the tiles  2206  in place on the extruded tray  2202 . For clarity of illustration, only one “T” cross bar  2204  is shown, so that springs, such as a wire form  2212  located therebeneath on the extruded tray  2202 , can be more easily seen. The wire forms  2212  then engage or snap into detents  2214  that are formed in corresponding locations in the sides of the tiles  2206  to engage and hold the tiles  2206  in place. The wire forms  2212  then form tray wire springs for the matching tile detent  2214  engagement configurations to snap the tiles  2206  in place on the extruded tray  2202 . 
     Referring now to  FIG. 23 , therein is shown an end view of an embodiment  2300  in which the tile  2302  itself serves as its own supporting structure. The tile  2302  thus incorporates a dovetail feature  2304  along the sides thereof for interlocking with adjacent tiles  2302 . By virtue of the dovetail feature  2304 , the tiles  2302  are then able to form a structurally integrated tile matrix. The tiles  2302  also have integral heat sinks  2306  that are oriented vertically on the backs or bottoms of the tiles  2302 . 
     In one embodiment, the tiles  2302  are formed as extruded tiles on which the LEDs  218  and electrical circuits  2308  are formed on the top surfaces thereof, such as by printing. Thermal grease (not shown) may additionally be utilized within the dovetail feature  2304  to ensure good heat conduction between the tiles  2302 . 
     Referring now to  FIG. 24A , therein is shown an isometric view of an embodiment  2400  in which the tiles  2402  are not only self-supporting, but in addition have high rigidity, light weight, substantial stiffness, and high torsional resistance, affording great and consistent co-planarity for the LEDs  218 . The tiles  2402 , which may be formed of a sheet metal construction, have sides  2404  depending at right angles therefrom. A foot  2406  may be attached to or formed in one or more of the sides  2404 , and provided with a screw hole  2408  for attaching the tiles  2402  to each other as well as to a supporting substrate, such as a display enclosure. An access hole  2410  may be provided in the tile  2402  for accessing a screw hole  2408  in an adjacent tile foot  2406 . 
     Referring now to  FIG. 24B , therein is shown a side view of an embodiment  2412  similar to the embodiment  2400  ( FIG. 24A ). Embodiment  2412  is attached by screws  2414  to a display shell  2416 , such as a display enclosure. Tiles  2418  in embodiment  2412  may also be provided, as appropriate, with cut-away sides  2420  for attaching PCBs  2422  directly to the tiles  2418 . Alternatively, the PCBs  2422  may be attached to and supported on the display shell  2416 , with the cut-away sides  2420  providing clearance for the PCBs  2422 . 
     Referring now to  FIG. 24C , therein is shown a side view of an embodiment  2424  similar to the embodiment  2400  ( FIG. 24A ) and the embodiment  2412  ( FIG. 24B ). In the embodiment  2424 , the tiles  2426  are attached to each other by fasteners  2428 , such as integrally formed clinch rivet metal fasteners. 
     Embodiments  2400 ,  2412 , and  2424  ( FIGS. 24A, 24B, and 24C , respectively) thus constitute box tiles that have bends that form a multi-sided box. The box tiles are structurally joined to each other to form a structurally integrated, substantially rigid, three-dimensional tile matrix. In one embodiment, a subset of the box tiles is thermally and structurally attached to an enclosure (e.g., the display shell  2416 ), and a subset of the box tiles is thermally and supportingly attached optionally to one or more electronic circuit boards (e.g., the PCBs  2422 ) that may be conveniently located in one or more cut-away sides  2420  of one or more of the box tiles. 
     Referring now to  FIG. 25A , therein is shown an isometric view of an embodiment  2500  in which tiles  2502  are formed, for example by extrusion, as interlockable tiles. In one embodiment, the tiles  2502  are interlockable extruded tiles that are structurally fitted together to join and interlock to each other to form a structurally integrated, rigid, three-dimensional, self-supporting tile matrix structure. 
     The tiles  2502  have fins  2504  around the periphery thereof that are configured in an interlocking geometry, that is, that provide for joining and interlocking the tiles  2502  to each other. The tiles  2502 , in one embodiment, also contain a slot  2506  that passes through the center or core of the tile  2502  to reduce the weight of the tile  2502  as well as increase the air thermal contact convection area and surface area thereof for enhanced heat exchange and dissipation. Increasing air thermal contact and improving heat exchange and dissipation can also be provided by the large surface area of the fins  2504 . 
     Where advantageous, additional elements, such as the spacers  302 , can be accommodated through the slot  2506  as well. 
     Referring now to  FIG. 25B , therein is shown a fragmentary top view of a frame  2508  in which the tiles  2502  have been assembled in interlocked, matrix form. Due to the three-dimensional and interlocking properties of the tiles  2502 , they are self-supporting, and can be configured and dimensioned to fit together, such as by a press-fit, to form a three-dimensional, self-supporting structural plate. The tile matrix may then be assembled into the frame  2508  for incorporation into a display. 
     Referring now to  FIG. 25C , therein is shown a partially exploded, fragmentary, isometric view of a display  2510  utilizing the structure of  FIG. 25B . The tiles  2502  have been press-fit together to form a three-dimensional structural plate, and these, in turn, have been incorporated into the frame  2508 . 
     A reflective sheet  2512  having holes  2514  therein may then be positioned on top of the tiles  2502 . The holes  2514  are positioned to match the locations of the LEDs  218 , so that the LEDs  218  then extend upwardly through the holes  2514 . The reflective sheet  2512  then reflects light from the LEDs  218  upwardly, increasing the brightness of the display  2510 . In one embodiment, the reflective sheet  2512  is configured as a reflective paper layer that is adjacent and substantially surrounding the individual LEDs  218  on the tiles  2502  to reduce light loss therefrom. 
     A cover sheet  2516  of suitable transparent material may then be located on top of the reflective sheet  2512 . 
     Referring now to  FIG. 25D , therein is shown a rear isometric view of the display  2510  attached by a pivot  2518  to a support arm stand assembly  2520 . In this embodiment, the three-dimensional matrix of the tiles  2502  is structurally mounted and interlocked to the frame  2508  of the display  2510  to form an integrated, unitized display assembly. The display  2510  is thus self-supporting, so that it can be attached directly to the support arm stand assembly  2520  through the integral pivot  2518  thereon. 
     Referring now to  FIG. 26 , therein is shown a fragmentary side cross-sectional view of an embodiment  2600  in which tiles  2602  in an LED tile matrix of a visual display light source are enhanced by LED edge lighting. The LED edge lighting is provided by an edge reflector  2604  on at least one edge, and preferably around the edges  2606 , of the LED tiles  2602 . The edge reflector  2604  may be conveniently supported by the tiles  2602  thereadjacent. The edge reflectors  2604  thus reduce dimming at the edges of a display screen  2608  by reflecting light, originating from the tiles  2602  of the LED tile matrix, back toward the screen  2608 . 
     Referring now to  FIG. 27A , therein is shown a fragmentary isometric exploded view of an embodiment  2700  having LED edge lighting that is provided by an additional LED light bank  2702  that is located at one or more of the edges  2704  of the tiles  2706  at the perimeter of the LED tile matrix that forms the visual display light source. The LED light banks  2702 , in one embodiment, may be directly supported by the tile  2706  thereadjacent, such as by a hook-and-slot configuration  2708  formed in the LED light bank  2702  and the tile  2706 . 
     Referring now to  FIG. 27B , therein is shown a fragmentary side cross-sectional view of the structure of  FIG. 27A  assembled into a display  2710 . Advantageously, the LED edge lighting that is provided by the LED light bank  2702  thus provides LEDs  2712  that extend beyond the outer dimensions of a screen  2714  that is being lighted thereby. 
     Referring now to  FIG. 28 , therein is shown a flow chart of a display system  2800  with a distributed LED backlight in an embodiment of the present invention. The display system  2800  includes providing a plurality of tile LED light sources, each tile LED light source having a tile and a plurality of similar LED light sources on each tile connected for emitting light therefrom, in a block  2802 ; orienting the plurality of tile LED light sources for illuminating a display from the back of the display in a block  2804 ; and integrating the plurality of tile LED light sources into a thermally and mechanically structurally integrated distributed LED tile matrix backlight light source in a block  2806 . 
     It has been discovered that the present invention thus has numerous aspects. 
     A principle aspect that has been unexpectedly discovered is that the present invention enables commercially viable displays for general consumption that not only afford the very highest quality, but are economical to manufacture, thin, lightweight, strong, and provide efficient light management capability in acceptable form factors and with acceptable cost. 
     Another aspect is that wire mazes, bulky circuit boards, heavy and bulky mounts and supports, and complicated heat removal configurations are not necessary with the present invention. 
     Another important aspect is that the present invention is thermally and mechanically structurally integrated into a distributed LED tile matrix backlight light source configuration that enables not only two-dimensional, but even more advantageously, three-dimensional structural integration, strength, and integrity. 
     Another aspect is that the structural integration of the LED light sources into a thermally and mechanically structurally integrated distributed LED tile matrix backlight light source provides for forming rows with increased rigidity. 
     Yet another aspect is that the present invention supports and facilitates integration of the LED tiles into structurally integrated multi-row arrays. 
     Still another aspect of the present invention is that the increased strength, rigidity, and integrity provide for readily maintaining array flatness. 
     Another aspect is that the structural integration of the LED light sources into a thermally and mechanically structurally integrated distributed LED tile matrix backlight light source provides for greatly improved thermal uniformity within and across the extent of the tile matrix backlight light source. 
     Another aspect is that the present invention is highly compatible with existing overall CCFL-based display system configurations and form factors. 
     Another significant aspect is that the present invention thus enables LED light source, large-size displays that deliver an excellent, consistent, and affordable consumer experience. 
     Yet another important aspect is that individual tiles and tile bars can be qualified before the display is assembled, virtually assuring that all the LEDs in the display will match and function properly even before the display is assembled. 
     Yet another significant aspect of the present invention is that it valuably supports and services the historical trend of reducing costs, simplifying systems, and increasing performance. 
     These and other valuable aspects of the present invention consequently further the state of the technology to at least the next level. 
     Thus, it has been discovered that the display system with the distributed LED backlight of the present invention furnishes important and heretofore unknown and unavailable solutions, capabilities, and functional aspects for display systems with a distributed LED backlight. The resulting processes and configurations are straightforward, cost-effective, uncomplicated, highly versatile and effective, can be surprisingly and unobviously implemented by adapting known technologies, and are thus readily suited for efficiently and economically manufacturing large size display devices. 
     While the invention has been described in conjunction with a specific best mode, it is to be understood that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the aforegoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the scope of the included claims. All matters hithertofore set forth herein or shown in the accompanying drawings are to be interpreted in an illustrative and non-limiting sense.

Metadata:
Filing Date: 20160415
Publication Date: 20190514
Grant Date: 20190514
Priority Date: 20070928
Inventors: HILLMAN, MICHAEL D.
TICE, GREGORY L.
LAW, WILLIAM SAUWAY
BAILEY, SEAN
TORRES, ANN
ALCORTA, EFRAIN
ANDERSON, PERRY
Assignee: APPLE INC
CPC Classifications: [{"code": "G02F1/133608", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133603", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F2001/133612", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F2001/133628", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133603", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133628", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133608", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133608", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/133612", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133628", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133603", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133612", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 40669529