Abstract:
The present invention provides an immersive rear projection display capable or providing aspect ratios of 2.66:1 or 4:1, or even greater. This allows viewers to be “immersed” in the images being displayed because the images can encompass both the direct and the peripheral views of a viewer. In one implementation, the immersive rear projection display includes two or more electronic projectors (e.g., three) that are positioned behind a curved translucent display screen. The electronic projectors project respective display images adjacent each other onto the display screen.

Description:
TECHNICAL FIELD  
         [0001]    The present invention relates to rear projection displays and, in particular, to an immersive rear projection display that includes a curved display screen.  
         BACKGROUND AND SUMMARY  
         [0002]    Standard computer-related and television displays have width-to-height aspect ratios of 1.33:1. The greater relative width of standard displays accommodates in part the relatively greater horizontal field of view of human vision. However, the relative horizontal field of view of human vision is significantly greater than the 1.33:1 aspect ratio of standard displays. As a consequence, a variety of display formats have been developed to better accommodate the relatively greater horizontal field of view of human vision. For example, high-definition television (HDTV) displays are characterized by aspect ratios of 16:9 (i.e., about 1.78:1), and the wide-screen cinematic displays such as Cinemascope® and Super Panavision® have aspect ratios of 2.35:1 and 2.55:1, respectively.  
           [0003]    Some electronic- or computer-based display systems project a display image onto a display screen for viewing by typically multiple viewers. These display systems employ an electronic or multimedia optical projector that may use liquid crystal cells, digital micro-mirrors, etc. to form a display image that is projected onto a display screen. Such electronic projectors are available under a variety of trademarks including Sony®, Hitachi®, Sharp®, In Focus®, Epson®, etc. In some implementations, the electronic projector is positioned in front of a reflective display screen (i.e., on the same side of the screen as the viewer). In other implementations, the electronic projector is positioned behind a translucent display screen (i.e., on the opposite side of the screen relative to the viewer). Conventional electronic projectors provide display images with the standard 1.33:1 aspect ratio.  
           [0004]    The present invention provides an immersive rear projection display capable or providing aspect ratios of 2.66:1 or 4:1, or even greater. This allows viewers to be immersed in the images being displayed because they can encompass both the direct and the peripheral views of a viewer. In one implementation, the immersive rear projection display includes two or more electronic projectors (e.g., three) that are positioned behind a curved translucent display screen. The electronic projectors project respective display images adjacent each other onto the display screen.  
           [0005]    The display screen is curved laterally about a vertical axis and reduces or eliminates perspective distortion that can otherwise occur at the edges of a flat screen. The display screen may be formed as a generally continuous curve with substantially no discontinuities in the curvature. In some implementations, the display may include pincushion distortion-compensating optical elements in association with the electronic projectors to compensate for pincushion distortion arising from projection of display images onto the curved display screen. Another aspect of this invention is that it may be implemented as a large-scale display for multiple viewers or in association with a desktop workspace that is configured and sized for viewing generally by only one viewer.  
           [0006]    Additional objects and advantages of the present invention will be apparent from the detailed description of the preferred embodiment thereof, which proceeds with reference to the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 is a diagrammatic illustration of a curved-screen immersive rear projection display.  
         [0008]    [0008]FIG. 2 is a front view of a display image rendered on a curved display screen by an electronic projector with conventional flat-screen projection optics.  
         [0009]    [0009]FIG. 3 is a schematic plan view of one implementation of a distortion-corrected optical path for an electronic projector directing a display image to display screen.  
         [0010]    [0010]FIG. 4 is a schematic plan view of another implementation of a distortion-corrected optical path for an electronic projector directing a display image to display screen.  
         [0011]    [0011]FIG. 5 is a front view illustration of a computer workstation curved-screen immersive rear projection display. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0012]    [0012]FIG. 1 is a diagrammatic rear illustration of a curved-screen immersive rear projection display  10  having three electronic projectors  12 A,  12 B, and  12 C, which are collectively referred to as electronic projectors  12  and are positioned behind a curved translucent display screen  14 . Electronic projectors  12  are well-known in the art and may employ any of a variety of electronically-controlled display technologies including liquid crystal displays, digital micromirrors (e.g., DLP™ digital light processing light controllers available from Texas Instruments Incorporated), etc., together with appropriate projection optics.  
         [0013]    It will be appreciated that immersive rear projection display  10  may include any number of two or more projectors  12 . The illustrated implementation with three electronic projectors  12 A,  12 B, and  12 C is merely exemplary. Electronic projectors  12  may be enclosed by a cabinet (not shown) that also supports display screen  14  about its periphery.  
         [0014]    Electronic projectors  12 A,  12 B, and  12 C project respective display images  16 A,  16 B, and  16 C on a rear surface of display screen  14  for viewing by one or more viewers  18  (one shown schematically) positioned in front of display screen  14 . Display images  16 A,  16 B, and  16 C may be adjacent segments of a single integrated display image, such as a wide-angle panoramic scene or an extended-width table, or may be separate, generally distinct display images. Display images  16 A,  16 B, and  16 C of respective electronic projectors  12 A,  12 B, and  12 C may correspond to the separate virtual desktops of a multi-monitor configuration that can be provided by various Windows®-brand operating systems, as well as various virtual desktop software utilities for graphical user interfaces.  
         [0015]    Curved display screen  14  includes a laterally concave shape relative to viewer  18  and may be formed relative to a vertical axis  20 . In one implementation, curved display screen  14  is formed as a generally continuous curve with substantially no discontinuities in the curvature. Also, curved display screen  14  may be formed with a generally consistent radius of curvature (i.e., generally as a circular segment), or without a generally consistent radius of curvature. Curved display screen  14  may be formed of any translucent material, but in one prototype implementation is formed of drawing vellum.  
         [0016]    The display images  16  formed by electronic projectors  12  may each include a conventional projection display aspect ratio of about 1.33:1 (width-to-height). As a result, the three electronic projectors  12 A,  12 B, and  12 C form on curved display screen  14  a combined display image with an aspect ratio of about 4:1. Similarly, an implementation of immersive rear projection display  10  with only two electronic projectors  12  a combined display image with an aspect ratio of about 2.66:1.  
         [0017]    Aspect ratios of 2.66:1, or 4:1, or even greater, as provided by the present invention, are greater than the aspect ratios of conventional displays. For example, standard computer-related and television displays have aspect ratios of 1.33:1 and high-definition television (HDTV) displays are characterized by aspect ratios of 16:9 (i.e., about 1.78:1). In addition, wide-screen cinematic displays such as Cinemascope® and Super Panavision® have aspect ratios of 2.35:1 and 2.55:1, respectively.  
         [0018]    Accordingly, the wider aspect ratios that can be provided by the present invention provide a display that can encompass a wide degree of peripheral vision of viewer  18 , thereby giving viewer  18  an impression of being immersed in the displayed image. While viewer  18  may be able to give direct attention to only the portion of the display screen  14  in the direct field of view, viewer  18  may rapidly and conveniently re-direct the field of view to other portions of display screen  14 . The lateral curvature of display screen  14  enhances the impression of viewer immersion and reduces or eliminates perspective distortion that can otherwise occur at the edges of a flat screen.  
         [0019]    [0019]FIG. 2 is a front view, as observed by viewer  18 , of a display image  16 B rendered on curved display screen  14  by an electronic projector  12  with conventional flat-screen projection optics. The following description is made with reference to display image  16 B as an example, but is similarly applicable to any other display image  16 .  
         [0020]    Display image  16 B illustrates pincushion distortion effects  30  and  32  (exaggerated for clarity) that can occur along respective top edge  34  and bottom edge  36  due to the lateral curvature of display screen  14  in combination with conventional flat screen projection optics. Pincushion distortion effects do not occur along lateral edges  38  and  40  of display image  16 B in the absence of a vertical curvature in display screen  14 .  
         [0021]    It will be appreciated that pincushion-corrected optical elements could be incorporated into electronic projectors  12  to compensate for and substantially reduce pincushion distortion effects  30  and  32 . In particular, appropriate compensating barrel distortion may be incorporated into the optical elements of electronic projectors  12 .  
         [0022]    [0022]FIG. 3 is a schematic plan view of one implementation of a distortion-corrected optical path  50  for electronic projector  12 B directing a display image to display screen  14 . The following description is made with reference to electronic projector  12 B as an example, but is similarly applicable to other electronic projectors  12 .  
         [0023]    Optical path  50  includes a curved, concave reflector  52  positioned to receive a projected image from electronic projector  12 B and reflect the projected image onto display screen  14 . Concave reflector  52  may have a parabolic, toroidal, or a spherical curvature. While a toroidal curvature could best compensate pincushion distortion effects  30  and  32 , a spherical or parabolic curvature would provide adequate compensation at a significantly reduced cost. In one simplified implementation, a conventional amateur astronomical mirror with a diameter of 10 inches or less may function as concave reflector  52 .  
         [0024]    [0024]FIG. 4 is a schematic side view of one implementation of a distortion-corrected optical path  60  for electronic projector  12 B directing a display image to display screen  14 . The following description is made with reference to electronic projector  12 B as an example, but is similarly applicable to other electronic projectors  12 .  
         [0025]    Distortion-corrected optical path  60  is analogous to distortion-corrected optical path  50  and includes a curved, concave reflector  62  positioned to receive a projected image from electronic projector  12 B and reflect the projected image onto display screen  14  via a flat fold mirror  64 . Distortion-corrected optical path  60  with flat fold mirror allow optical path  60  to be folded and more compact than a comparable distortion-corrected optical path  50 .  
         [0026]    [0026]FIG. 5 is a front view illustration of a computer workstation curved-screen immersive rear projection display  70  that includes a computer workstation  72  having at least one computer input device  74  in communication with a computer  76 . Although illustrated as being local to workstation  72 , computer  76  may alternatively be located remotely.  
         [0027]    Multiple (e.g., three) electronic projectors  80  are positioned behind a curved translucent display screen  82  and are in communication with computer  76  to receive display image signals from which to project respective computer display images adjacent each other onto display screen  82 . Display screen  82  may be formed with a radius of curvature of about 34 inches (86 cm) and may have a height  84  of 12 inches (30 cm) and a length  86  of 48 inches (120 cm).  
         [0028]    Having described and illustrated the principles of our invention with reference to an illustrated embodiment, it will be recognized that the illustrated embodiment can be modified in arrangement and detail without departing from such principles. In view of the many possible embodiments to which the principles of our invention may be applied, it should be recognized that the detailed embodiments are illustrative only and should not be taken as limiting the scope of our invention. Rather, I claim as my invention all such embodiments as may come within the scope and spirit of the following claims and equivalents thereto.