Abstract:
Light ( 22 ) is projected from an image projector ( 20 ), in response to an image information signal ( 18 ) and is controllably refracted in response to a first control signal ( 26 ), for projecting refracted light ( 27 ) onto a screen ( 28 ). The screened light is for providing viewable images of varying size occupying all or part of the screen. The viewable images are refracted in response to a second control signal ( 64 ) for viewing the images of increasingly smaller size with correspondingly increasing magnification.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   Priority is claimed under 35 U.S.C. 119( e ) from U.S. Provisional Application Ser. No. 60/264,812 filed Jan. 29, 2001. 

   BACKGROUND OF INVENTION 
   1. Technical Field 
   The present invention relates to acquiring images and, more particularity, to displaying such images for viewing with varying accommodation. 
   2. Discussion of Related Art 
   The granularity of a given static man-made image of a real object is only as good as that of the imaging technology used to acquire and present it. Closer inspection with a magnifying glass or other aid to eyesight does not ultimately reveal any deeper granularity but only the limitations of the imaging technology used. This is not usually a problem for the enjoyment of images in books, movies, and other conventional media 
   On the other hand, the granularity of real objects is unlimited as far the human eye is concerned. Considering the eye itself, with increased focus, more detailed granularity of objects is always revealed. Moreover, with technological aids to the eye, e.g., the magnifying glass, the optical microscope, the electron microscope and other scientific tools, smaller details are always revealed. 
   A recent motion picture or video innovation provides successive images to the eye at varying apparent distances for viewing with correspondingly varying focus (accommodation) of the eye. With increased magnification merely at the viewer&#39;s end, however, because of the limitations of man-made imaging technology, there is not any increased level of granularity available for inspection. If the magnification is also increased at the camera end there will be increased granularity but the viewer with increased accommodation will focus on only a small part of the entire field-of-view presented. The effect is reduced granularity. Therefore, the verisimilitude of the imagery under increased magnification is a problem. 
   SUMMARY OF INVENTION 
   An object of the present invention is to provide images of objects in a scene at varying distances that provide increased granularity to close-ups. 
   According to a first aspect of the present invention, a method is provided comprising the steps of projecting light from an image projector, in response to an image information signal, controllably refracting said projected light, in response to a first control signal, for projecting refracted light for providing viewable images of varying extent, and controllably refracting said viewable images in response to a second control signal for viewing said images of increasingly smaller extent with correspondingly increasing magnification. 
   According to a second aspect of the present invention, a device is provided, comprising a projector, responsive to an image information signal, for providing first light rays, a first optic, responsive to the first light rays and to a first control signal, for providing second light rays, a screen, responsive to the second light rays, for providing third light rays indicative of images of varying size, and a second optic, responsive to the third light rays and to a second control signal, for providing fourth light rays for viewing. 
   According to a third aspect of the invention, a device is provided, comprising an image projector for projecting light in response to an image information signal, a first optic for controllably refracting said projected light, in response to a first control signal, for providing light rays of varying extent, and a second optic for controllably refracting said light rays in response to a second control signal for providing light rays of increasingly smaller extent at correspondingly decreasing focal length. 
   These and other objects, features, and advantages of the present invention will become more apparent in light of a detailed description of a best mode embodiment thereof which follows, as illustrated in the accompanying drawing. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a system including a device for showing images to an eye of a user. 
       FIG. 2  shows a video camera collecting images of a scene illuminated by a light source with an eye of a cameraman shown using an eyepiece to view the scene being photographed and having a sensed eye signal encoded along with video information. 
       FIG. 3  shows light rays projected to form an image that fills or almost fill the entire area or extent of a screen. 
       FIG. 4  shows light rays projected to form an image that only partially fills the entire extent of the screen. 
       FIG. 5  shows light rays projected to form an image that only fills a small extent of the entire extent of the screen. 
       FIG. 6  is similar to  FIG. 1 , except the control signal is sensed not from the eye of the cameraman, but from the eye of the user. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 1  shows a device  10  for showing images to an eye  12  of a user. A video signal is received on a line  14  by a control  16 . The video signal contains image information which is decoded and provided on a signal line  18  to for instance an image projector  20  which projects images with first light rays  22  to a first optic  24 . The optic  24  may for instance be lens that is under the control of a control signal on a line  26  from the control  16 . The control signal on the line  26  is decoded by the control  16  from the video signal on the line  14 . The optic  24  refracts or otherwise bends the light rays  22  into second light rays  27  that are projected onto a translucent screen  28  to form images of different sizes, i.e., that fill the screen  28  to a greater or lesser extent as shown in  FIGS. 3-5 , as discussed below. The images on the screen  28  are projected as third light rays  29 . It should be realized that the screen need not be translucent but could be reflective. The signal on the line  14  can be provided in many different ways. It should first of all be realized that the signal on the line  14  need not be a single line (which implies some form of multiplexing) but could be two or more signal lines. 
   Secondly, as a first example of a way to provide the signal on the line  14 , referring to  FIG. 2 , a video camera  30  is shown collecting images of a scene  32  illuminated by a light source  34 . An eye  36  of a cameraman is shown using an eyepiece  38  for viewing the scene being photographed. A sensor  40  such as an eye accommodation sensor senses the accommodation of the eye  36 . The sensor  40  provides a sensed signal on a line  42  to an optic control  44 . The optic control  44  provides a camera optic control signal on a signal line  46  to a motorized camera optic  48 . The optic control  44  causes the motorized optic  48  to focus on the scene  32  at differing focal lengths according to changes in the accommodation of the eye  36  as detected by the sensor  40 . The optic  48  casts rays  50  onto an image sensor  52  that provides a video image signal on a line  53  to a combiner  54 . It combines, e.g., in a time division multiplexed way, the image signal on the line  53  with the signal on the line  42  to form the video data signal on the line  14  (see FIG.  1 ). As explained above, the signal on the line  42  could be provided in parallel on a separate signal line alongside the signal on the line  14 . In that case, it would only carry video information. 
   Referring now back to  FIG. 1 , it will be realized from the foregoing that the control signal on the line  26  changes the projected light rays  22  by means of the optic  24  according to changes detected in the cameraman&#39;s eye  36  of  FIG. 2  by the sensor  40 . In other words, the signal on the line  42  from the sensor  40  is not only used to control the optic  48 , but is encoded in the signal on the line  14  along with the image information and used also to control the optic  24 . The nature of the change in the projected light rays  22  is manifested by the manner in which the light rays  27  are projected onto the screen  28 . Examples are shown in  FIGS. 3-5 . If the eye  36  of  FIG. 2  is detected by the sensor  40  viewing the scene  32  with a long focal distance, such as infinity, the optic control  44  causes the optic  48  to focus at a correspondingly long distance. The optic  48  focuses the scene  32  at infinity and projects the details of the scene with a wide field of view onto the image sensor  52 . Consequently, the available sensor  52  pixels are spread over a relatively wide field of view. In other words, the granularity of the image is spread over a wide field of view.  FIG. 3  shows the light rays  27  projected to form an image  54  that fills or almost fills the entire area or extent of the screen  28 . 
   If the eye  36  of  FIG. 2  is detected by the sensor  40  viewing the scene  32  with an intermediate focal distance, the optic control  44  causes the optic  48  to focus at a correspondingly intermediate distance. The optic  48  focuses the scene  32  at the intermediate distance and projects the details of the scene with an intermediate field of view onto the image sensor  52 . Consequently, the granularity, i.e., the available sensor pixels are spread over a relatively intermediate field of view that is less in extent than the relatively wide field-of-view  54  of FIG.  3 .  FIG. 4  shows the light rays  27  projected to: form an image  56  that only partially fills the entire extent of the screen  28 . 
   If the eye  36  of  FIG. 2  is detected by the sensor  40  viewing the scene  32  with a short focal distance, the optic control  44  causes the optic  48  to focus at a correspondingly short distance. The optic  48  focuses the scene  32  at a correspondingly short distance and projects the details of the scene with a narrow field of view onto the image sensor  52 .  FIG. 5  shows the light rays  27  projected to form an image  58  that only fills a small extent of the entire extent of the screen  28 . Consequently, the available sensor pixels are spread over a relatively narrow field of view  58  that is less in extent than the intermediate field of view  56  of FIG.  4 . Particular objects within the narrowed field of view  58  of  FIG. 5  can be viewed with more granularity than those same objects could be with the granularity provided by that of FIG.  4  and even more so than that of FIG.  3 . 
   Referring back to  FIG. 1 , as explained above, the light rays  27  are projected onto the screen  28  with different fields-of-view, areas or extents  54 ,  56 ,  58 , all of which have the same total number of pixels. The advantage of this approach is that with the aid of an optic  60 , the field of view of the eye  12  of the viewer can be fully occupied with all of these pixels even though the accommodation of the eye  12  changes. The total number of pixels can be spread over the full used extent of the retina in all cases by a combination of changes in the focal length of the optic  60  and the accommodation of the eye  12 . When the optic  48  of the camera  30  of  FIG. 2  focuses in on a detail of the wider scene  32 , it increases the granularity of the imaged scene in that area. At the same time, the optic  24  causes the size of the image to be reduced on the screen  28 . In other words, when the focal length of the optic  48  is shortened to capture a narrowed field of view of the scene with increased magnification, the granularity of that smaller portion of the imaged scene increases as manifested in a smaller area on the screen  28 . The focal length of the optic  60  is controlled by a control signal on a line  64  from the control  16  to allow the eye  12  to accommodate, i.e., to focus closer onto the scene with increased granularity in a smaller area of interest. In other words, at the same time that the control signal on the line  26  causes the optic  24  to reduce the extent to which the screen  28  is filled by imagery (see FIG.  4 ), the signal on the line  64  causes the optic  60  to reduce the field of view provided for the eye  12 , e.g., by increasing its magnification. Thus, the optic  60  refracts the rays  29  to provide fourth light rays  65  in such a way that the eye  12  must change its accommodation so as to bring the image into focus. This causes the field of view of the eye  12  to be fully occupied with an up-close image. 
   If the cameraman&#39;s eye  36  changes to a long view of the scene  32 , as explained above, the image  54  ( FIG. 3 ) fills the screen  28  because the control signal on the line  26  causes the optic  24  to expand the extent to which the screen  28  is filled by imagery. At the same time, the signal on the line  64  causes the optic  60  to expand the field of view provided for the eye  12 , e.g., by reducing its magnification or increasing its focal length. The eye  12  changes its accommodation accordingly. In other words, when the control signal on the line  26  causes the optic  24  to increase the extent to which the screen  28  is filled by imagery, as in  FIG. 3 , the signal on the line  64  causes the optic  60  to increase the field of view provided for the eye  12  even further, e.g., by decreasing its magnification even more. 
     FIG. 6  shows a variation of  FIG. 1  where instead of sensing the cameraman&#39;s eye, the eye of the user is sensed. As shown, an eye sensor  70  senses an eye of a user, for instance by sensing accommodation. A control signal having a magnitude indicative thereof is provided on a line  74  to a control  76  which provides it on a line  78  to a network  80 . The network provides the control signal on a line  82  to a camera  84 . An input/output device  86  is responsive to the control signal on the line  82  and provides it on a line  88  to an optic control  90  which controls a lens  92  by means of a signal on a line  94 . In this way, the camera&#39;s magnification is controlled remotely by the user&#39;s eye  72  instead of locally by a cameraman&#39;s eye. 
   At the same time, light rays  96  focused by the lens  92  and cast upon an image sensor  98  are converted to an electrical signal on a line  100  and provided to the input/output means  86  for transmission on the line  82  via the network and the line  78  to the control  76 . An image signal is provided on a line  102  to a projector  20  for projecting light rays  22  to an optic  24  for projection as rays  27  onto a translucent screen  28 . A backlit image formed on the screen  28  provides light rays  29  to an optic  60  that projects rays  118  to the eye  72  of the user. Besides controlling the lens  92 , the signal on the line  74  is used by the controller  76  to provide optic control signals on lines  120 ,  122  for controlling the optics  108 ,  116  in providing images with differing field of view at different sizes as shown in  FIGS. 3-5 . 
   It should be realized that the sensed property of the user&#39;s eye need not be accommodation. For instance, eye direction could be sensed. Moreover, it should also be realized that the control signal need not be derived from a sensed eye at all. It could be provided for instance by a mouse or other control device employed by the user, by the cameraman, by a director, or by someone else to control magnification of the imagery. Likewise, the imagery need not be obtained from a camera, but could be generated from a computer or a drawing, painting, or hand-drawn animation. Although a real image is shown projected onto a screen, the optics  108 ,  116  could be arranged to present a virtual image to the eye of the user without any intermediate screen. It should also be realized that the imagery could be provided as stereoscopic images