Abstract:
A stereoscopic viewing system permits separate imaging of left and right images of a particular object. Each image may be sequentially captured on the exact same imaging sensor and then transferred either to storage or for separate stereoscopic display. As a result, a single image sensor may be utilized to reduce costs of the system without significantly decreasing the time for display.

Description:
BACKGROUND 
     This invention relates generally to stereoscopic or three-dimensional imaging wherein left and right image pairs are captured on an image sensor. 
     A conventional stereoscopic image capture device utilizes a pair of separate imaging systems. Each imaging system captures an image of an object from a different perspective. The resulting captured images, called left and right image pairs, may be viewed in tandem to create the effect of three-dimensional viewing. Alternatively, the image pairs can be computer-combined to create a three-dimensional representation of the imaged scene. 
     Necessarily, two complete optical systems with accompanying image sensors are utilized to provide such systems. This results in at least doubling the cost of the system for three-dimensional applications. 
     Therefore, there is a need for a way to enable stereoscopic imaging without significantly increasing the cost of the system. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic depiction of one embodiment of the present invention; 
     FIG. 2 is a schematic depiction of another embodiment of the present invention; 
     FIG. 3 is a block diagram in accordance with one embodiment of the present invention; and 
     FIG. 4 is a flow chart for software in accordance with one embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION 
     Referring to FIG. 1, an imaged object O may be separately imaged by a stereoscopic imaging system  10 . A left and right image pair is successively captured on the image sensor  24 . A first front element optics  12   a  receives light from the object O and passes it through transfer optics  14   a.  The resulting image is reflected by a 45 degree mirror  16   a  where it passes through or is blocked by a shutter  18   a.    
     From the shutter  18   a  the image is passed and is reflected by the integrating optics  20 . The optics  20  may be an optical beam combiner in one embodiment. The resulting image is then passed through the focusing optics  22  to the sensor  24 . The sensor  24  is conventionally a charge-coupled device or complementary metal oxide semi-conductor sensor  24  that captures a digital representation of the image. 
     The sensor  24  captures a right image from the optics  12   a  through  18   a  and transfers the captured image to a storage  36  shown in FIG. 3. A left image is captured by the optics that includes the second front element optics  12   b,  transfer optics  14   b,  mirrors  16   b,  and shutter  18   b.  When the right image is to be captured, the shutter  18   a  is open and the shutter  18   b  is closed. Conversely, when the left image is being taken, the shutter  18   b  is open and the shutter  18   a  is closed. 
     As a result, left and right images may be successively captured by the sensor  24  and transferred to an associated storage  36 . From the storage  36 , the captured images may be presented for left and right viewing or may be combined using appropriate image processing techniques to generate a three-dimensional representation of the captured object O. 
     Because each optical path is identical, the resulting left and right images are of substantially identical quality. Therefore, the left and right images may be effectively combined in some embodiments. 
     In one embodiment, the left and right images may be taken in rapid succession using a “burst mode” on the system  10  to avoid temporal blur or artifacts. The two captured left and right image fields may then be processed by the imaging device  10  or a host computer (not shown) to form a three-dimensional perspective of the object being imaged. 
     In some embodiments, the system  10  may be a digital camera, a video camera, a digital imaging system, or an imaging device for use in connection with computer games, binoculars or a microscope, to mention a few examples. 
     In some embodiments, the form factor may be relatively small and less expensive. The use of a single sensor may result in reduced complexity and cost. The system permits an adjustable parallax in a single system. The spacing between systems including lenses  12   a  and  12   b  may be adjusted. In fact, the transfer optics spacing may even be asymmetrical. 
     The two optical paths may share the same back end focusing optics. The length to the optical transfer path may be varied allowing for non-matching path lengths depending on system design. This also allows for an expandable distance between the taking lens and allows the construction on variable stereo separation of images. 
     In some embodiments, a&#39;single set of optics may be used by removing the frontal element optics  12   a  and  12   b  and transferring the image via mirrors allowing for scenarios similar to that of a simple periscope. 
     In some embodiments, the shutters  18  may be mechanical shutters. In other embodiments, electronic shutters such as liquid crystal shutters may be utilized. 
     Referring to FIG. 2, the transfer optics may be replaced with fiber optic cables  26 . The flexible fiber optic cable  26  is used so that the location of the optical paths becomes even more adaptable. Thus, the spacing between the optics  12   a  and  12   b  may be readily adjusted using a flexible optical cable  26 . 
     Referring to FIG. 3, an electrical system  30  for use with the imaging system  10  may include a bus  34 . The bus  34  is coupled to an analog to digital converter  32  that converts the analog output from the image sensor  24  into a digital format. The captured images may be transferred over the bus  34 , under control of the controller  40 , to the storage  36 . Software  38  also stored on the storage  36  may control the capture and transfer of images. A display  41  may also be coupled to the bus  34 . 
     In accordance with one embodiment of the present invention, software  38  may be utilized to enable control over operations of the systems  10  and  30 . In other embodiments, the control may be done by hard-wired logic. 
     Referring to FIG. 4, the software  38  begins by determining whether stereo imaging has been selected as determined at diamond  42 . If so, the shutters  18   a  and  18   b  may be set appropriately to capture either the left or right image as indicated in block  44 . An image is then captured as indicated in block  46 . That captured image may be burst transferred to the storage  36  over the bus  34  as indicated in block  48 . The shutters  18  are reset during the image transfer process in one embodiment of the present invention as indicated at block  50 . The next image is captured and transferred as indicated in block  52  to create a left and right stereo pair. 
     While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.