Abstract:
A stereoscopic coupler for mechanically and optically coupling an endoscope to a portion of a camera, the stereoscopic coupler comprising: 
     means for mechanically and optically coupling the stereoscopic coupler to an endoscope; and 
     means for mechanically and optically coupling the stereoscopic coupler to a portion of a camera; 
     wherein the stereoscopic coupler comprises: 
     a pair of optics; 
     a mechanical actuator for operation by a user; and 
     means for physically moving the pair of optics as a unit in response to movement of the mechanical actuator by the user.

Description:
REFERENCE TO PENDING PRIOR PATENT APPLICATION 
       [0001]    This patent application claims benefit of pending prior U.S. Provisional Patent Application Ser. No. 61/328,776, filed Apr. 28, 2010 by Douglas Sjostrom et al. for OPTICAL ADAPTER FOR STEREO ENDOSCOPIC CAMERA (Attorney&#39;s Docket No. VIKING-3 PROV), which patent application is hereby incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to visualization systems in general, and more particularly to stereoscopic visualization systems. 
       BACKGROUND OF THE INVENTION 
       [0003]    A typical stereo endoscopic camera comprises two image sensors (e.g., CCD or CMOS sensors). The image sensors may be of a single-chip construction, or they may comprise 3-chip sensor blocks that include 3 sensors attached to a color-separating prism. The image sensors receive optical images generated by a stereo endoscope. Typically an opto-mechanical adapter (i.e., a stereoscopic coupler) is disposed between the stereo endoscope and the stereo endoscopic camera. The stereoscopic coupler generally serves three purposes: (i) it provides a secure mechanical locking mechanism between the stereo endoscope and the stereo endoscopic camera; (ii) it houses coupling optics for projecting the images from the stereo endoscope on the two image sensors of the stereo endoscopic camera; and (iii) it provides the focusing means for the coupling optics housed by the stereoscopic coupler. 
         [0004]    Opto-mechanical adapters for non-stereo endoscopes and cameras are commonly available products in the industry and are well known to those skilled in the art. 
         [0005]    Stereo endoscopes differ from their non-stereo counterparts in that they are more sensitive to optical misalignments. Not only must each channel of the stereo endoscope be properly optically aligned with the image sensors of the stereo endoscopic camera for the best image, but also key optical parameters for each channel (e.g., magnification, boresight, image rotation, image focus, etc.) must be identical between the two channels or an unwanted parallax will be created in the system, causing depth distortions and user strain/fatigue associated with converging the two images. 
         [0006]    Prior art stereoscopic couplers all suffer from one or more deficiencies, including complexity of design, difficulties in maintaining optical alignment, cost of manufacture and maintenance, etc. 
         [0007]    Thus there is a need for a new and improved stereoscopic coupler for mechanically and optically coupling a stereo endoscope to a stereo endoscopic camera. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention provides a new and improved stereoscopic coupler for mechanically and optically coupling a stereo endoscope to a stereo endoscopic camera. This new and improved stereoscopic coupler provides precision alignment between the optics of the stereo endoscope and the optics of the stereo endoscopic camera, and provides an easy-to-use locking mechanism to secure the stereo endoscope to the stereo endoscopic camera. 
         [0009]    In one preferred form of the invention, there is provided a stereoscopic coupler for mechanically and optically coupling an endoscope to a portion of a camera, the stereoscopic coupler comprising: 
         [0010]    means for mechanically and optically coupling the stereoscopic coupler to an endoscope; and 
         [0011]    means for mechanically and optically coupling the stereoscopic coupler to a portion of a camera; 
         [0012]    wherein the stereoscopic coupler comprises: 
         [0013]    a pair of optics; 
         [0014]    a mechanical actuator for operation by a user; and 
         [0015]    means for physically moving the pair of optics as a unit in response to movement of the mechanical actuator by the user. 
         [0016]    In another preferred form of the invention, there is provided a stereoscopic coupler for mechanically and optically connecting an endoscope to a portion of a camera, the stereoscopic coupler comprising: 
         [0017]    means for mechanically and optically coupling the stereoscopic coupler to an endoscope; and 
         [0018]    means for mechanically and optically coupling the stereoscopic coupler to a portion of a camera; 
         [0019]    wherein the stereoscopic coupler comprises: 
         [0020]    an element for ensuring axial alignment between an endoscope and the stereoscopic coupler; 
         [0021]    an element for ensuring horizontal alignment between an endoscope and the stereoscopic coupler; and 
         [0022]    a releasable element for releasably securing an endoscope to the stereoscopic coupler. 
         [0023]    In another preferred form of the invention, there is provided a stereoscopic coupler for mechanically and optically coupling an endoscope to a portion of a camera, the stereoscopic coupler comprising: 
         [0024]    means for mechanically and optically coupling the stereoscopic coupler to an endoscope; and 
         [0025]    means for mechanically and optically coupling the stereoscopic coupler to a portion of a camera; 
         [0026]    wherein the stereoscopic coupler comprises: 
         [0027]    optics; 
         [0028]    a mechanical actuator for operation by a user; and 
         [0029]    means for physically moving the optics as a unit in response to movement of the mechanical actuator by the user. 
         [0030]    In another preferred form of the invention, there is provided a method for mechanically and optically coupling a stereo endoscope to a stereo endoscopic camera, the method comprising: 
         [0031]    providing a stereoscopic coupler for mechanically and optically coupling an endoscope to a portion of a camera, the stereoscopic coupler comprising: 
         [0032]    means for mechanically and optically coupling the stereoscopic coupler to an endoscope; and 
         [0033]    means for mechanically and optically coupling the stereoscopic coupler to a portion of a camera; 
         [0034]    wherein the stereoscopic coupler comprises: 
         [0035]    a pair of optics; 
         [0036]    a mechanical actuator for operation by a user; and 
         [0037]    means for physically moving the pair of optics as a unit in response to movement of the mechanical actuator by the user; 
         [0038]    mounting the stereoscopic coupler to the stereo endoscopic camera; and 
         [0039]    mounting the stereo endoscope to the stereoscopic coupler. 
         [0040]    In another preferred form of the invention, there is provided a method for mechanically and optically coupling a stereo endoscope to a stereo endoscopic camera, the method comprising: 
         [0041]    providing a stereoscopic coupler for mechanically and optically connecting an endoscope to a portion of a camera, the stereoscopic coupler comprising: 
         [0042]    means for mechanically and optically coupling the stereoscopic coupler to an endoscope; and 
         [0043]    means for mechanically and optically coupling the stereoscopic coupler to a portion of a camera; 
         [0044]    wherein the stereoscopic coupler comprises: 
         [0045]    an element for ensuring axial alignment between an endoscope and the stereoscopic coupler; 
         [0046]    an element for ensuring horizontal alignment between an endoscope and the stereoscopic coupler; and 
         [0047]    a releasable element for releasably securing an endoscope to the stereoscopic coupler; 
         [0048]    mounting the stereoscopic coupler to the stereo endoscopic camera; and 
         [0049]    mounting the stereo endoscope to the stereoscopic coupler. 
         [0050]    In another preferred form of the invention, there is provided a method for mechanically and optically coupling a stereo endoscope to a stereo endoscopic camera, the method comprising: 
         [0051]    providing a stereoscopic coupler for mechanically and optically coupling an endoscope to a portion of a camera, the stereoscopic coupler comprising: 
         [0052]    means for mechanically and optically coupling the stereoscopic coupler to an endoscope; and 
         [0053]    means for mechanically and optically coupling the stereoscopic coupler to a portion of a camera; 
         [0054]    wherein the stereoscopic coupler comprises: 
         [0055]    optics; 
         [0056]    a mechanical actuator for operation by a user; and 
         [0057]    means for physically moving the optics as a unit in response to movement of the mechanical actuator by the user; 
         [0058]    mounting the stereoscopic coupler to the stereo endoscopic camera; and 
         [0059]    mounting the stereo endoscope to the stereoscopic coupler. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0060]    These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein: 
           [0061]      FIG. 1  is a schematic distal-end view showing a novel stereoscopic coupler formed in accordance with the present invention; 
           [0062]      FIG. 2  is a schematic proximal-end view of the stereoscopic coupler shown in  FIG. 1 ; 
           [0063]      FIG. 3  is a schematic view showing a stereo endoscope connected to the stereoscopic coupler shown in  FIG. 1 ; 
           [0064]      FIG. 4  is a schematic view showing the stereoscopic coupler of  FIG. 1  connected to a stereo endoscopic camera; 
           [0065]      FIGS. 5 and 6  are schematic sectional views showing various components of the stereoscopic coupler shown in  FIG. 1 ; 
           [0066]      FIG. 7  is a schematic exploded view showing various components of the stereoscopic coupler shown in  FIG. 1 ; 
           [0067]      FIG. 8  is a schematic view showing various aspects of the stereo endoscope shown in  FIG. 3 ; and 
           [0068]      FIG. 9  is a schematic view showing selected additional aspects of stereoscopic coupler shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0069]    Looking first at  FIGS. 1 and 2 , there is shown a novel stereoscopic coupler  5  for mechanically and optically coupling a stereo endoscope to a stereo endoscopic camera.  FIGS. 3 and 4  show stereoscopic coupler  5  secured to a stereo endoscope  10  ( FIG. 3 ) and stereoscopic coupler  5  secured to a stereo endoscopic camera  15  ( FIG. 4 .). 
         [0070]    Functionally, and looking next at  FIGS. 5-7 , stereoscopic coupler  5  may be considered to constitute three main sections, each providing a different function and serving a different purpose: 
         [0071]    (i) a “scope locking” section situated distally on stereoscopic coupler  5  and comprising the distal portion of the main housing  20 , front flange  25 , front cover  30 , a bail  35  and a radial locating pin  40 ; 
         [0072]    (ii) a “focusing mechanism” section situated primarily in the middle of the stereoscopic coupler and comprising the middle portion of the main housing  20 , focusing ring  45 , binocular cell housing  50 , cam ring  55 , elastomeric seals  60 A,  60 B, load ring  65 , clutch plate  70 , return springs  75 A,  75 B, and cam pin sockets  80 A,  80 B; and 
         [0073]    (iii) a “camera attachment” section situated proximally on stereoscopic coupler  5  and comprising the proximal portion of the main housing  20  and a sensor mounting plate  85  which is mounted to the image sensor (not shown) of stereo endoscopic camera  15 . 
         [0074]    The following is the description of some of the distinct features and operational principles of stereoscopic coupler  5 . 
       The “Scope Locking” Section 
       [0075]    The “scope locking” section receives, aligns and securely locks in place a stereo endoscope (e.g., the stereo endoscope  10  shown in  FIGS. 3 and 8 ). Stereo endoscope  10  typically has two optical channels  90 A,  90 B ( FIG. 8 ) separated by a predetermined distance. 
         [0076]    The theoretical plane passing through the optical axes of the two optical channels  90 A,  90 B defines the horizontal plane  95  of the system. For proper performance of the stereo endoscopic system, two alignments are essential: (a) the axial alignment of each optical channel  90 A,  90 B of the stereo endoscope  10  with its corresponding optical channel of the stereo endoscopic camera  10 , and (b) the horizontal alignment of the endoscope horizontal plane  95  with the corresponding horizontal plane of the stereo endoscopic camera  10 . 
         [0077]    The present invention provides highly precise axial and horizontal alignment of the coupling optics of the stereoscopic coupler with respect to the endoscope optics. 
         [0078]    As shown in  FIGS. 5-7 , the clutch plate  70  has a hollow central shaft  100  fabricated by precision machining and a centerless grinding technique known to those skilled in the art. The distal portion of main housing  20  has a cylindrical protrusion  105  that fits into hollow shaft  100  of clutch plate  70 , thereby axially locating main housing  20  relative to clutch plate  70 . On its distal side, main housing  20  has a central blind hole  110  that receives the corresponding central pin  115  ( FIG. 8 ) of stereo endoscope  10 . Thus, stereo endoscope  10  is precisely axially aligned with hollow shaft  100  of clutch plate  70 . 
         [0079]    Horizontal alignment of stereo endoscope  10  is achieved by radial locating pin  40  and corresponding grooves  120 A,  120 B ( FIG. 8 ) formed in the proximal portion of stereo endoscope  10 . 
         [0080]    Stereo endoscope  10  is detachably connected to stereoscopic coupler  5  ( FIG. 3 ) by means of the scope locking section. More particularly, in order to attach stereo endoscope  10  to stereoscopic coupler  5 , the adapter&#39;s spring-loaded bail  35  is depressed against the force of springs  125  so as to open up the entire distal cavity of main housing  20 . Stereo endoscope  10  is then inserted into the distal end of stereoscopic coupler  5  in such a way that the endoscope&#39;s central pin  115  is received by blind hole  110  of main housing  20  of the stereoscopic coupler while one of the endoscope&#39;s peripheral grooves  120 A,  120 B aligns with the radial locating pin  40  of the stereoscopic coupler. After full insertion of the proximal end of the stereo endoscope into the distal end of the stereoscopic coupler, the spring-loaded bail  35  is released so that the bail locks stereo endoscope  10  to stereoscopic coupler  5  by exerting force at the endoscope&#39;s proximal chamfered surface  130  ( FIG. 8 ) towards main housing  20  of the stereoscopic coupler. It can also be seen from  FIG. 5  that binocular cell housing  50  has a cylindrical central internal surface  135  riding on hollow central shaft  100  of clutch plate  70 . This arrangement ensures precise axial alignment of the coupling optics  140  that are housed in the corresponding openings  145 A and  145 B of the binocular cell housing  50  ( FIGS. 7 and 9 ) . 
         [0081]    It should be appreciated that the symmetry of the design with respect to the horizontal plane  95  allows for two possible attachments of stereo endoscope  10  to stereoscopic coupler  5 , with 180° angular relations between each position, i.e., radial locating pin  40  may be received in either one of the peripheral grooves  120 A,  120 B of the stereo endoscope. 
         [0082]    It should also be appreciated that, if desired, two radial locating pins  40  may be provided on the distal portion of main housing  20 , with the two radial locating pins  40  being diametrically opposed across the diameter of main housing  20 , so that one radial locating pin  40  may be received in the endoscope&#39;s peripheral groove  120 A and the other radial locating pin  40  may be received in the endoscope&#39;s peripheral groove  120 B. Again, even where two radial locating pins  40  are provided, the symmetry of the design allows for two possible attachments of stereo endoscope  10  to stereo coupler  5 , with 180° angular rotation between each position, i.e., one radial locating pin  40  may be received one of the peripheral grooves  120 A,  120 B of the stereo endoscope and the other radial locating pin  40  may be received in the other of the peripheral grooves  120 A,  120 B of the stereo endoscope. 
       The “Focusing Mechanism” Section 
       [0083]      FIGS. 5-7  and  9  show details of the focusing mechanism section of stereoscopic coupler  5  (in  FIG. 9 , main housing  20  has been removed for clarity). When focusing ring  45  is rotated, cam ring  55  turns with it as a unit. The rigid connection between focusing ring  45  and cam ring  55  is provided by cam pins  150  which extend between cam pin seats  155  on cam ring  55  and cam pin sockets  80 A and  80 B (see  FIG. 5 ) in focusing ring  45 . The protruding fingers  160 A and  160 B of binocular cell housing  50  are pressed to the cam surfaces  165 A,  165 B of cam ring  55  by the springs  75 A and  75 B. Rotation of cell housing  50  is prevented by precisely machined grooves  170 A and  170 B of load ring  65 . As the cam ring  55  turns clockwise and counterclockwise in response to counterpart rotation of focusing ring  45  by the user, binocular cell housing  50  moves axially in proximal and distal directions, respectively, whereby to move coupling optics  140  axially, in a coupled manner, in proximal and distal directions, respectively. 
         [0084]    Thus, it will be seen that, in view of the foregoing construction, when focusing ring  45  is rotated about its axis, cam ring  55  rotates correspondingly and causes, via camming action, axial movement of binocular cell housing  50 , and therefore axial movement of coupling optics  140 , within stereoscopic coupler  5 . Significantly, coupling optics  140  move in conjunction with one another in a coupled manner. 
         [0085]    The present invention also allows for adjustment of the amount of torque required for rotation of focusing ring  45 . This is done by adjusting the amount of friction force created between load ring  65  and cam ring  55 . As can be seen in  FIG. 9 , while cam ring  55  rotates, it maintains a certain surface contact with load ring  65  (shown in  FIG. 9  by numeral  175 ). The friction force between load ring  65  and cam ring  55  impacts the torque of focusing ring  45 . The friction force is determined by the axial force created between the two parts that is applied by compression springs  180 A and  180 B. The compression of these springs  180 A,  180 B is adjustable via threaded plungers  185 A,  185 B situated at the proximal ends of springs  180 A,  180 B ( FIG. 7 ). 
       The “Camera Attachment” Section 
       [0086]    Stereoscopic coupler  5  may be permanently or detachably connected to stereo endoscopic camera  15 . Appropriate sealing means well known in the art (e.g., O-rings, bal-seals, quad-rings, plastic gaskets and the like) are provided between the stereoscopic coupler and the stereo endoscopic camera so as to ensure a hermetically-sealed assembly. 
         [0087]    The above description outlines the preferred embodiments of the invention. Other embodiments are also possible within the framework of the invention. For instance, in the preferred embodiment, the binocular cell housing  50  is moved axially by cam ring  55 . Alternatively, axial motion of binocular cell housing  50  may be effected by a lead screw rigidly connected to the focus ring. In this case, binocular cell housing  50  would have a corresponding threaded central hole. Still other means for effecting axial motion of binocular cell housing  50  will be apparent to those skilled in the art in view of the present disclosure. 
       Modifications Of The Preferred Embodiments 
       [0088]    It should be understood that many additional changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the present invention, may be made by those skilled in the art while still remaining within the principles and scope of the invention.