Abstract:
A metadisplay comprising a plurality of subdisplays, each subdisplay comprising a microdisplay for displaying a subimage, and FTFOB having an FTFOB entrance end and an FTFOB exit end, wherein said entrance end is optically coupled to said microdisplay for transmitting said subimage from said entrance end to said exit end, whereby said exit end provides a subdisplay face with said subimage.

Description:
[0001]     The present application claims the benefit of U.S. provisional patent application No. 60/684,633, filed May 24, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to video displays. More specifically, it relates to combining a plurality of smaller (micro)displays to make one larger (meta)display.  
         [0004]     2. Description of Prior Art Including Information Disclosed Under 37 CFR 1.97 and 1.98  
         [0005]     Information relevant to attempts to address these problems can be found in U.S. Pat. Nos. 4,299,447 to Soltan, et al; 6,304,703 to Lowry; 6,618,529 to Lowry. However, each one of these references suffers from one or more of the following disadvantages: mechanical complexity, necessity for an elaborate frame structure; lack of integration between the image source and driving electronics, difficulty in easily and permanently aligning the signal source (e.g. the microdisplay) with the optics.  
       BRIEF SUMMARY OF THE INVENTION  
       [0006]     Miniature displays, a.k.a. “microdisplays” are discussed in U.S. Pat. No. 5,920,080 and others assigned to “FED Corporation” and/or to its successor, “Emagin Corporation” (assignee of the present application) and hereby incorporated by reference). Microdisplays, which comprise OLEDs, are fabricated like silicon computer chips, “wafers” of single crystal silicon. The organic light-emitting diode (OLED) itself is integrated with its display electronics in a kind of microdisplay “chip”. Each silicon “wafer” may have on the order of one hundred microdisplay chips, arranged like cookies on a baking sheet. These chips have at the center of their surface an “active area” which may comprise an active light-emitting device such as an OLED. This active area is surrounded by an area which does not emit light or images, which may comprise electronics, and which forms a sort of a border around the active area. It is this border which prevents simply “tiling” the microdisplays, i.e. placing them adjacent one another in a large mosaic-like array, to form a larger display. Heretofore this had proved difficult, impossible, or infeasible.  
         [0007]     However, in accordance with the system according to the present invention, a plurality of small, high-resolution microdisplays can be combined to provide a large high-resolution image, such as would ordinarily be obtainable only from a large single microdisplay.  
         [0008]     A large composite metadisplay face, displaying a metaimage, is realized by “tiling” a plurality of smaller subdisplay faces, each displaying the subimage at the exit end of a fused fiber optic bundle, the entrance end of which is optically coupled to a microdisplay; together these constitute a subdisplay. (Bundles of optical fibers, like individual optical fibers, are said to have an “entrance” end (where light enters the fiber) and an “exit” end (where light leaves the fiber), as is well known to those of ordinary skill in the relevant art.) By having the fused fiber optic bundle “tapered”, i.e. by making the entrance end and exit end areas of different sizes, the microdisplay&#39;s image (sometimes referred to herein as the subdisplay&#39;s subimage) passing through the FTFOB may be magnified (when the exit end area&gt;the entrance end area) by the fused tapered fiber optic bundle (hereinafter sometimes referred to a FTFOB). The FTFOB exit ends may be brought into abutment to together form, from the subdisplay faces, a larger “metadisplay”. The metadisplay has a single surface, which may be planar, or, alternatively, may be milled into one of a variety of shapes,—e.g., concave, convex, or any arbitrary surface. The single metadisplay surface displays a single metaimage composed of the many subimages of the many subdisplays.  
         [0009]     A smaller microdisplay can provide a larger image in accordance with the system according to the present invention, in which an image to be displayed (sometimes called a “subject image”; e.g. a single frame of film, depicting a scene), is separated into a total of n×m image parts (called “subimages”) for display on an n×m array of microdisplays, where n is the number of microdisplays in each row, and m is the number of microdisplays in each column, and each (“subimage”) is displayed on a separate microdisplay. Together these subimages make up a “metaimage” in a fashion reminiscent of the way the pieces of a jigsaw puzzle together make up the jigsaw puzzle picture. However, unlike each piece of a jigsaw puzzle, which each has a subimage across its entire surface (i.e. it has no frame or border, with the image going right to the edge of the piece), each microdisplay chip has the subimage across only part of its surface, the rest of the surface being taken up with a physical border, which may comprise, e.g. driver electronics, etc. Thus, the subimages cannot be placed into adjacency simply by placing the microdisplay chips into adjacency, and merely putting the microdisplay chips into adjacency would leave the borders abutting, with a big border separating each subimage. To bring the subimages into adjacency without borders between them, the subimages are brought into adjacency by having the image brought into a kind of light pipe (an FTFOB, discussed elsewhere herein) which has two ends, one of which is optically coupled to the active are of a microdisplay, and the other end of which displays the subimage, without any border, so that it may be brought into adjacency with the subimages found on the end of the other light pipes. As will discussed later herein, each light pipe may in some embodiments optically enlarge to a size greater than that of the microdisplay producing it, to a size equal to or even greater than the area of the microdisplay, thus allowing the display of adjacent images from adjacent (or abutting) microdisplays, even though the active areas on the adjacent microdisplays are not themselves adjacent (or abutting).  
         [0010]     Each microdisplay chip is therefore fashioned into what is termed a “subdisplay”, which comprises (i) a microdisplay chip containing an OLED capable of providing a subimage, the OLED being at least optically and sometimes also directly physically coupled to a the entrance end of a Fused Tapered Fiber Optic Bundle (FTFOB) which Conducts the image, and, in some embodiments, also enlarges it.  
         [0011]     It is not intended that the invention be summarized here in its entirety. Rather, further features, aspects and advantages of the invention are set forth in or are apparent from the following description and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     To the preceding, and to such other objects that may hereinafter appear, the present invention relates to a video display, as set forth in detail in the herein specification and recited in the annexed claims, taken together with the accompanying drawings, wherein like numerals refer to like parts and in which:  
         [0013]      FIG. 1  is a front view of metadisplay  100  showing the composite metadisplay face  110  with metaimage  400  and subdisplay faces  202 ,  204 ,  206 , and  208  of subdisplays  200 S,  205 S,  210 S, and  215 S, respectively.  
         [0014]      FIG. 2  is a side view of the device of  FIG. 1  showing, inter alia, in more detail the structure and layout of the subdisplays  200 S,  205 S, ( 210 S, and  215 S not shown for clarity), i.e. showing fused tapered fiber optic bundles (FTFOBs)  200 F,  205 F, ( 210 F and  215 F not shown for clarity), respectively.  
         [0015]      FIG. 3  is the view of  FIG. 1  with the FTFOBs removed, showing in more detail the structure and layout of the subdisplays behind the face of the metadisplay.  
         [0016]      FIG. 4  is a side view similar to  FIG. 2 , but which shows an exemplary alternative embodiment showing a metadisplay face with a concave surface. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]     Reference is now made to  FIG. 1 , a front view which shows metadisplay  100  and metadisplay face  110 , which comprises the subdisplay faces  202 ,  204 ,  206 , and  208  (a.k.a. the ends of fused tapered fiber optic bundle ends  202 ,  204 ,  206 , and  208 ) of subdisplays  200 S,  205 S,  210 S, and  215 S (respectively).  
         [0018]     Reference is now made to  FIG. 2 , which is a side view of  FIG. 1 , giving a side view of the metadisplay  100 . Subdisplays  200 S and  205 S have as their subimage source OLEDs  200 L and  205 L, respectively, which are coupled to FTFOBs  200 F and,  205 F, respectively. (Note further that a description of these fused tapered fiber optic bundles (FTFOBs) may be found in U.S. Pat. No. 5,303,373 (hereby incorporated by reference). FTFOBs are commercially available, e.g. from the Schott Optical company of Sturbridge, Mass. An FTFOB, is, as its name indicates, a bundle of optical fibers, effectively fused together along their length into one large fiber, and tapered so that the fiber bundle&#39;s two ends are of different sizes. This general type of “tapered fused fiber optic bundle” a.k.a. “fused tapered fiber optic bundle” is used to implement the system according to the present invention.  
         [0019]     Reference is now made to  FIG. 2 , which is a side view of  FIG. 1 , giving a side view of the metadisplay  100 . In particular,  FIG. 2  shows subdisplays  200 S and  205 S, including (respectively) FTFOB  200 F and FTFOB  205 F, and the structure beneath each.  
         [0020]     Subdisplay  200 S comprises FTFOB  200 F, which in turn comprises FTFOB  200 F entrance end  201  (which has a width indicated as W 1 ) and FTFOB  200 F exit end  202  (which has a width indicated as W 2 ). As previously explained, an image present at the FTFOB  200 F entrance end  201  will appear at the FTFOB  200 F exit end  202 , in a width equal to the original width magnified by the factor (W 2 /W 1 ) FTFOB  200 F entrance end  201  is both optically coupled and physically coupled to OLED  200 L, which itself is integral with silicon chip  825 , which is mounted on Printed Circuit Board (PCB)  225 . Also mounted on PCB  225  are surface-mount PCB components  235  and video driver connector  250 . Note that each OLED active area, e.g. the OLED active areas of OLEDs  200 L and  205 L, are overlying larger printed circuit boards (PCBs)  225  and  1225 .  
         [0021]     Subdisplay  205 S is similar to subdisplay  200 S, in that it comprises FTFOB  205 F, which in turn comprises FTFOB  205 F entrance end  203  (which has a width indicated as W 1 ) and FTFOB  205 F exit end  204  (which has a width indicated as W 2 ). (Of course, FTFOB  205  also has a “depth” which is into the page of the drawing, and is not shown for clarity of the drawing; it is understood that magnification, etc. in the “depth” dimension occurs in a fashion similar to how it does in the “width” dimension.) Subdisplay  105 S differs from subdisplay  200 S in that, to illustrate an alternative embodiment according to the present invention, FTFOB  205 F has a Fused Fiber Optic Faceplate (“faceplate”)  1150  between it and OLED  205 L, so that FTFOB  205 F is physically coupled to faceplate  1150 , which is physically coupled to OLED  205 L, thereby optically coupling OLED  205 L to FTFOB  205 F. Of course, OLED  205 L is integral with silicon chip  850 , which is mounted on Printed Circuit Board (PCB)  1225 . Fused Fiber Optic Faceplate (“faceplate”)  1150  is similar to an FTFOB, but without the taper, and is of a type readily available from the Schott optical company of Southbridge, Mass., USA.  
         [0022]     Faceplate  1150 , which has advantages including that it protects OLED  205 L during assembly, may be held in place with a suitable optical adhesive. (For illustrative purposes,  FIG. 2  shows subdisplay  200 S without a faceplate, but shows subdisplay  205 S with a faceplate ( 1150 ); it should be understood that, in a typical application, a faceplate is likely to be used either on all subdisplays, or on none.  
         [0023]     Whether or not a faceplate is used, there is an interior space, labeled “Δ±ε”, between the edges of any adjacent PCBs, e.g. PCB  225  and PCB  1225  This space Δ±ε is required to allow adjustment of each OLED&#39;s active area to precisely match the input face of the taper, as such adjustment may be needed to allow for tolerances in the components and assembly of the display.  
         [0024]     Reference is now made to  FIG. 3 , which is a view of  FIG. 1  with the FTFOBs  200 F,  205 F,  210 F,  215 F of subdisplays  200 S,  205 S,  210 S, and  215 S removed, showing in more detail and in top view the outline of the structure underlying the subdisplays  200 S,  205 S,  210 S, and  215 S of the metadisplay  100 .  
         [0025]     The faces of subdisplays  200 S and  205 S (a.k.a. exit ends  201  and  204 ) of FTFOBs  200 F and  205 F, are in tight abutment, as shown, for example, at abutment lines  204 ,  207 ,  211 , and  213 . This close abutment is achieved by proper shaping of the FTFOBs, e.g. by cutting them so that the fibers illuminated at the edges of adjacent displays, e.g. at edges  291  and  292  of  200 L and  205 L, respectively ( FIG. 2 ) abut in very close proximity at the top of the FTFOBs (e.g. at abutment line  207 ).  
         [0026]     Note that subdisplays  200 S,  205 S,  210 S and  215 S have subimages  300 ,  305 ,  310 , and  315 , respectively, displayed on OLEDs  200 L,  205 L,  210 L and  215 L, also respectively. Note further that each of these subimages is a quarter of a circle, and that, together, these subimages compose the full circle of metaimage  400  ( FIG. 1 ).  
         [0027]     Reference is now made to  FIG. 4 , which is a view similar to that of  FIG. 2 , but which depicts an alternative embodiment in which the exit surfaces  5201  and  5204  of fiber taper  5200  and fiber taper  5205  (respectively) have been shaped (via machining, milling, chamfering, polishing, and/or any other suitable process) to make a single continuous, arbitrary surface  5206 . (While in this illustrative example the single continuous, arbitrary surface  5206  is concave, it should be readily understood that the surface could be of any arbitrary shape, whether concave, convex, irregular, flat, etc.) The alternative embodiment of  FIG. 4  is in all other respects similar to that of  FIGS. 1-3 , discussed above.  
         [0028]     Although illustrative embodiments of the present invention, and various modifications thereof, have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to this precise embodiment and the described modifications, and that various changes and further modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. For example, although for illustrative purposes a metadisplay has been shown to comprise a small number of subdisplays, e.g. four (4) subdisplays arranged in a 2×2 tiling, it will be readily apparent to the reader and to those of ordinary skill in the relevant arts that the metadisplay may comprise a larger number of subdisplays or a fewer number than illustrated here, as the invention is scalable. (Indeed tiling patterns may also vary, e.g. long and narrow 1×n, square n×n, rectangular n×m, or irregular, depending on what aspect ratio or display shape is desired.)