Abstract:
An illuminable image-conducting optical assembly includes an illuminable image-transporting optical fiber bundle having (i) an inner image-conducting bundle with opposed image-input and image-output faces and (ii) a plurality of illumination conduits disposed peripherally about the image-conducting bundle. The illumination conduits include light-emission ends that combine to define a light-output face. A translucent optics housing includes light-entrance and light-exit ends and an inside surface defining an optics channel for housing at least one optical element. The optical fiber bundle and the optics housing cooperatively couple such that (a) at least one housed optical is element is in optical communication with the image-input face in order to facilitate the projection of an image of an object of interest onto the image-input face and (b) the light-output face of the fiber bundle is in optical communication with the light-entrance end of the optics housing such that light introduced into the light-collection end of an illumination conduit enters the light-entrance end, and emits from the light-exit end, of the optics housing so as to facilitate illumination of the object to be imaged onto the image-input face.

Description:
PROVISIONAL PRIORITY CLAIM 
       [0001]    Priority based on Provisional Application, Ser. No. 60/817,825 filed Jun. 30, 2006, and entitled “LIGHT-CONDUCTIVE OPTICS HOUSING FOR CREATING AN ILLUMINATING HALO ADJACENT AN END OF AN OPTICAL FIBER IMAGE BUNDLE” is claimed. The entirety of the disclosure of the previous provisional application, including the drawings, is incorporated herein by reference as if set forth fully in the present application. 
     
     BACKGROUND 
       [0002]    Known in the optical-fiber component fabrication field is an optical fiber bundle that includes a first set of imaging fibers bundled with a second set of illuminating fibers arranged, for example, circumferentially or, more generally, peripherally, about the imaging fibers as viewed into a plane orthogonal to a longitudinal axis of the imaging and illuminating fibers. Also known to those in the optical fiber industry is that the purpose of such bundles is to form an illuminating “halo” in the vicinity of an object for which an image is to be acquired by, and transported through, the bundled imaging fibers to a remote sensing location. An example of such a “halo” fiber bundle is schematically represented in  FIG. 1A . Typically, a device such as that shown in  FIG. 1A  is assembled from inner and outward fiber bundles, wherein the outward bundle is comprised of illuminating fibers that transport light from a remote source or sources to the light-output end of the outer bundle and the inner bundle is comprised of imaging fibers having an image-input end arranged proximate to focusing optics (e.g., a lens doublet). In order to accommodate and house focusing optics, arrangements such as that of  FIG. 1B  are fabricated. In the bundle of  FIG. 1B , the light-output end of the outer, illuminating bundle extends beyond the image-input end of the inner, imaging bundle in order to define a void or channel for the mounting of the focusing optics. Where, for instance, the inner and outer bundles are cylindrical, a cylindrical void is defined, and analogously for various cross-sectional bundle geometries. 
         [0003]    Difficulties abound in the fabrication of illuminable image-transporting fiber bundles of the general configuration shown in  FIG. 1B . A first, typical method fabrication involves the separate fabrication of the inner and outer bundles and then the introduction of the inner bundle into the outer bundle. A second method involves the fabrication of the inner bundle and then the assembly and securement of outer-bundle fibers about the inner bundle. In either event, the frequently small and fragile structures require handling by very skilled operators and/or very sophisticated automation equipment, either of which adds to the expense of fabrication. Moreover, the tolerances that are necessary for assembly, particularly those associated with the first method, are difficult to maintain and often reduce the usable surface(s) of the component. Still further, at least the end face of the inner bundle must be finished (e.g., ground and polished) before the outer bundle is arranged about the inner bundle, which increases the exposure of the finished inner face to the potential for damage during subsequent steps in the fabrication process. In still additional, alternative aspects, end portions of mutually fused imaging fibers are machined away to form an image-input face that is recessed with respect to a peripheral light-emission face in order to form a void or channel into which, for example, one or more optical elements (e.g., a lens) is mounted for focusing an image onto the image-input face. In a typical version consistent with the current state of the art, the optics mounted into the void or channel adjacent the image-input face are permanently mounted and, therefore, non changeable. It will be appreciated that machining for the purposes creating a channel to house optics subjects the fused image bundle to damage such as the shattering or splintering of constituent fibers that, as one will readily appreciate, results in the degradation of image input and transport through the image bundle. Moreover, polishing the recessed image-input face is difficult and may result in damage to surrounding illumination fibers. 
         [0004]    Accordingly, there exists a need for a simplified assembly including an illuminable image-transporting optical fiber bundle and optics for focusing images into the image-input face thereof. Moreover, there is a need for versions of such an assembly capable of retaining in optical communication with the image-input face, alternative sets of optics. 
       SUMMARY 
       [0005]    In accordance with a first illustrative set of embodiments, an illuminable image-conducting optical assembly includes an illuminable image-transporting optical fiber bundle (also referred to as “illuminable image bundle”) and optics housing configured for cooperative coupling with the illuminable image bundle. The illuminable image bundle has an inner image-conducting bundle including first and second image-bundle ends and a plurality of light-conductive imaging conduits extending between the first and second ends. Each imaging conduit includes first and second ends and has the capacity to conduct light between its first and second ends by total internal reflection. The first ends of the imaging conduits terminate at and define an image-input face at the first image-bundle end and the second ends of the imaging conduits terminate at and define an image-output face at the second image-bundle end. 
         [0006]    Peripherally disposed about the image-conducting bundle is a plurality of illumination conduits. Each illumination conduit includes a light-collection end and a light-emission end opposite the light-collection end. As with the imaging conduits, the illumination conduits are capable of transmitting light between the light-collection and light-emission ends by total internal reflection. In a typical embodiment, plural light-emission ends combine to define a light-output face. Moreover, the light-output face is typically more proximate the image-input face than the image-output face of the image-conducting bundle. 
         [0007]    The optics housing extends between first and second housing ends and includes a housing wall that is fabricated, at least partially, from a translucent material. For purposes of the current specification, and the appended claims, “translucent” means “not entirely or completely opaque.” Accordingly, “translucent” as defined herein covers the range from totally transparent to nearly, but not totally, opaque. The housing wall includes opposed light-entrance and light-exit ends and inside and outside surfaces extending between the light-entrance and light-exit ends. Moreover, the inside surface of the housing wall defines an interior optics channel. The optics channel is configured for housing an optical element set that includes at least one optical element such as, by way of non-limiting example, a focusing element such as a lens or graded-refractive-index element, an optical filter, an optical isolating element such as baffle, and a reflective element such as mirror or mirrored surface. 
         [0008]    In an operative mode, the optics housing is cooperatively coupled with the illuminable image-transporting optical fiber bundle such that (i) at least one of the at least one optical elements housed by the optics housing is in optical communication with the image-input face of the image-conducting bundle in order to facilitate the projection of an image of an object of interest that is external to the optics channel onto the image-input face; and (ii) the light-output face defined by the plural light-emission ends is in optical communication with the light-entrance end of the optics housing such that light introduced into the light-collection end of an illumination conduit enters the light-entrance end of the housing wall for transmission to, and emission from, the light-exit end of the housing wall so as to facilitate illumination of the object to be imaged onto the image-input face. 
         [0009]    Envisioned within the scope and contemplation of various versions as defined in the appended claims are kits wherein at least one of (i) the illuminable image-transporting optical fiber bundle and the optics housing are configured for selective cooperative coupling such that the optics housing is capable of alternative removal from and attachment to the illuminable image-transporting optical fiber bundle and (ii) the optics housing and optical element set are configured such that the optical element set is selectively retainable within and removable from the optics channel. Various such kits include at least one of (i) a set of optics housings including at least two optics housings and (ii) set of at least two optical element sets. In the first instance, optics housings may be alternatively attached to the illuminable image-transporting optical fiber bundle, while, in the second instance, plural optical elements sets may be alternatively retained within the optics channel. While either option increases the versatility of the assembly kit, versions in which both the optics housing and the optical element sets can be changed render possible the selective assembly of a greater number of cooperatively-coupled component combinations than is possible with either option alone. 
         [0010]    Among the advantages of various versions providing for the coupling of an optics housing, such as that described above, with an illuminable image bundle are (i) obviation of difficult and expensive techniques such as cutting away portions of imaging fibers to create a void for the mounting of optics; (ii) facilitation of the “mixing” of illuminating light entering the housing from discrete illumination fibers; and (iii) interchangeability of housings and associated optics or of optical element sets within the housing, although the first two advantages are realizable in versions in which both or either of the optics housing and the optical element set are permanently affixed. 
         [0011]    Representative, non-limiting embodiments are more completely described and depicted in the following detailed description and the accompanying drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1A  shows a traditional illuminable image-transporting fiber bundle in which an inner bundle of adjacently-fused image-conducting optical fibers, or imaging fibers, is peripherally surrounded by a plurality of illuminating fiber; 
           [0013]      FIG. 1B  depicts a an illuminable image-transporting fiber bundle in which an image-input face defined at one end of the inner image-conducting bundle is recessed with respect to a peripheral light-emission face defined collectively by the light-emission ends of plural illuminating fibers in order to form a void or channel into which one or more optical elements (e.g., a lens) is mounted for focusing an image onto the image-input face; 
           [0014]      FIG. 2  depicts an illuminable image-conducting optical assembly embodying aspects of the present invention and including a light-conductive optics housing having a translucent housing wall defining an optics channel that houses an optical element set and an illuminable image bundle that is cooperatively coupled with the optics housing; 
           [0015]      FIG. 2A  is a cross-sectional view into the plane IIA of  FIG. 2 ; 
           [0016]      FIG. 2B  is a cross-sectional view into the plane IIB of  FIG. 2 ; 
           [0017]      FIG. 3  shows an optical assembly, alternative to that of  FIG. 2 , in which the image-input face of the inner image-conducting bundle extends beyond the light-output face defined by the light-emission ends of the illumination conduits so as to define a stepped shoulder about which a portion of the optics housing is peripherally disposed and mounted; 
           [0018]      FIG. 3A  is a cross-sectional view into the plane IIIA of  FIG. 3 ; 
           [0019]      FIG. 4A  depicts an illustrative embodiment in which the optics housing and the illuminable image bundle are configured for selective threadable coupling; 
           [0020]      FIG. 4B  depicts an embodiment, alternative to that of  FIG. 4A , in which the optics housing and the illuminable image bundle are configured for selective threadable coupling; 
           [0021]      FIG. 5A  shows an embodiment in which, irrespective of whether the optics housing is selectively separable from the illuminable image bundle, the optical element set is selectively retainable within the optics channel of the optics housing; and 
           [0022]      FIG. 5B  illustrates another alternative version in which the optical element set is selectively retainable within the optics channel of the optics housing. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    The following description of various embodiments of a light-conductive optics housing optically coupled with an illuminable image-transporting optical fiber bundle is illustrative in nature and is therefore not intended to limit the scope of the invention or its application of uses. Accordingly, the various implementations, aspects, versions and embodiments described in the summary and detailed description are in the nature of non-limiting examples falling within the scope of the appended claims and do not serve to define the maximum scope of the claims. 
         [0024]    In a first illustrative configuration shown in  FIGS. 2 ,  2 A and  2 B, a cylindrical light-conductive optics housing  100  extends between open first and second housing ends  110  and  112 . A housing wall  114  extends between the first and second housing ends  110  and  112  and includes a light-entrance end  116  and a light-exit end  118  that coincide with, respectively, the first and second housing ends  110  and  112 . Moreover, the housing wall  114  includes inside and outside surfaces  115   a  and  115   b  extending between the light-entrance and light-exit ends  116  and  118 . The housing wall  114  defines an optics channel  120  that is bounded by the inside surface  115   a  and configured to house an optical element set  130  including at least one optical element. In the illustrative embodiment of  FIG. 2 , the optical element set  130  comprises a lens doublet  132  including first and second lenses  132   a  and  132   b.  However, it is to be understood that the optical element set  130  in various versions may include in addition to, or instead of, either or both of first and second lenses  132   a  and  132   b,  at least one of (i) an additional lens, (ii) a graded-refractive index focusing element, (iii) a dispersive element such as a prism, grating or grism, and (iii) an optical filter, by way of non-limiting example. At least a portion of the housing wall  114  is translucent such that light introduced into the housing wall  114  through the light-entrance end  116  is transmitted through the housing wall  114  for emission from the light-exit end  118 . 
         [0025]    Referring still to  FIG. 2 , the optics housing  100 , and the optical element set  130  housed thereby, are in optical communication (i.e., optically coupled) with an illuminable image-transporting optical fiber bundle  200  which, for convenience and brevity, is alternatively referred to as illuminable image bundle  200  or by some similar designation. The illuminable image bundle  200  includes an inner image-conducting bundle  210  having first and second image-bundle ends  212  and  214  and a plurality of light-conductive imaging conduits  220  (e.g., optical fibers) extending between the first and second image-bundle ends  212  and  214 . Referring to  FIGS. 2 and 2B , each imaging conduit  220  includes first and second ends  222  and  224  and comprises an optically transmissive core  230  having an imaging-core refractive index. Each core  230  is surrounded by a cladding material  232  having an imaging-cladding refractive index lower than the imaging-core refractive index such that light propagates through the imaging conduit  220  by total internal reflection in accordance with principles well-known to those of ordinary skill in the related art. The first ends  222  of the imaging conduits  220  terminate at, and combine to define, an image-input face  216  at the first image-bundle end  212 . Analogously, the second ends  224  of the imaging conduits  220  terminate at, and define, an image-output face  218  at the second image-bundle end  214 . 
         [0026]    Disposed circumferentially about the image-conducting bundle  210  is a plurality of bundled illumination conduits  250  (e.g., optical fibers). Each illumination conduit  250  includes a first, light-collection end  252  and a second, light-emission end  254  opposite the light-collection end  252 . In alternative versions, the light-collection ends  252  of the illumination conduits  250  collect light from a single remote light source (not shown) or from multiple remote light sources (not shown). Plural light-emission ends  254  combine to define a light-output face  258 . In the particular illuminable image bundle  200  of  FIG. 2 , the light-output face  258  is annularly disposed about the first ends  222  of the imaging conduits  220  such that the light-output face  258  and the image-input face  216  form a first common face  270 . Moreover, in the particular version of  FIG. 2 , the first common face  270  is planar, but, in various versions within the scope and contemplation of the invention, is alternatively configured. Furthermore, in alternative versions, the optical coupling is retained permanently, such as by the application of an adhesive (e.g., optical epoxy E O ) to and between the light-output face  258  of the illuminable image bundle  200  and the light-entrance end  116  of the optics housing  100 . 
         [0027]    Depicted in  FIGS. 3 and 3A  is an embodiment alternative to that of  FIGS. 2 ,  2 A and  2 B. In most of its aspects, the version of  FIGS. 3 and 3A  includes elements analogous to those of the version of  FIGS. 2-2B  and, therefore, the same reference characters are used to identify like elements associated with the two alternative versions. In the version of  FIGS. 3 and 3A , the image-input face  216  of the image-conducting bundle  210  does not define with the light-output face  258  a common face, such as common face  270  shown in  FIG. 2 . More specifically, while in the version of  FIGS. 3 and 3A  the light-emission ends  254  of the illumination conduits  250  define a light-output face  258  that is annularly disposed about the image-conducting bundle  210 , the light-output face  258  is recessed by a distance DR relative to the image-input face  216  such that a stepped shoulder  272  separates the image-input face  216  and the light-output face  258 . As shown in  FIG. 3 , a configuration in which the image-input face  216  extends beyond the light-output face  258  facilitates the protrusion of a portion of the length of the image-conducting bundle  210  into the optics channel  120  of a compatibly dimensioned optics housing  100 . Shown in  FIG. 3A  is a view into cross-sectional plane IIIA of  FIG. 3 , which is taken along a portion of the image-conducting bundle  210  that protrudes into the optic channel  120  and shows that, along this protruding portion, the image-conducting bundle  210  is surrounded by the optics housing  100 . In a version such as that of  FIG. 3 , an adhesive such as epoxy E, for example, may be applied to a portion of the stepped shoulder  272  extending along overlapping portions of the lengths of the image-conducting bundle  210  and the optics housing  100  to retain the optics housing  100  in a fixed position relative to the illuminable image bundle  200 . In addition to contributing to overall structural integrity of the joint between the optics housing  100  and the illuminable image bundle  200 , stepped shoulder  272 , by providing a length-wise extending portion along which to apply an adhesive, obviates the need to apply adhesive to the light-entrance end  116  of the housing wall  114  and the light-output face  258 , thereby preserving the integrity of light transmission at the light interface I L  defined between the light-entrance end  116  and the light-output face  258 . 
         [0028]    Referring to  FIGS. 4A and 4B , alternative versions are shown in which the optics housing  100  is threadably coupled to the illuminable image bundle  200 . One advantage envisioned in association with such embodiments is the ability to selectively remove and attach different optics housings  100  retaining optical element sets  130  with different optical elements to the illuminable image bundle  200 . The illustrative version of  FIG. 4A  is in most major respects similar to that of  FIG. 2  and, therefore, like reference characters are used to refer to analogous elements. In the version of  FIG. 4A , however, a portion of the length of the illuminable image bundle  200 , beginning at the light output face  258 , is provided with a first external-thread set  282 . In the particular version depicted, the external-thread set  282  is formed on a first threaded collar  280  that is annularly affixed about a portion of the length of the illuminable image bundle  200 . However, it will be appreciated that the illuminable image bundle  200  may be otherwise provided with an external-thread set  282 . Similarly, a portion of the length of the optics housing  100 , beginning at the light-entrance end  116 , and extending toward the light-exit end  118 , has affixed thereabout a second threaded collar  180  that carries a second external-thread set  182 . The optics housing  100  and illuminable image bundle  200  are selectively coupled by an internally-threaded coupler  300  that has defined therein a first internal-thread set  302   a  into which threads of the first external-thread set  282  are threaded and a second internal-thread set  302   b  into which threads of the second external-thread set  182  are threaded. It is to be understood that alternative versions may include an internally-threaded coupler  300  that is permanently affixed (e.g. and not threaded) about one of the illuminable image bundle  200  and the optics housing  100 , while the other of the optics housing  100  and the image bundle  200  is threaded into the threaded coupler  300 . 
         [0029]    Referring to  FIG. 4B , a version including a stepped shoulder  272  such as that exhibited by the version of  FIG. 3  is shown. To the extent that elements of the versions of  FIGS. 4B and 3  are analogous, they are identified by like reference characters. Referring now to  FIG. 4B , at least a portion of the stepped shoulder  272  extending along a portion of the length of the inner image-conducting bundle  210  carries inner-bundle external threads  292 . In the particular version shown, the inner-bundle external threads  292  are defined about the exterior surface of a inner-bundle threaded collar  290  that is affixed about that portion of the inner bundle  210  protruding beyond the light-output face  258 . However, it will be appreciated that the portion of the inner bundle  210  protruding beyond the light-output face  258  may be otherwise provided with inner-bundle external threads  292 . Beginning adjacent the light-entrance end  116 , a portion along the length of the optics housing  100  includes housing internal threads  192  configured for selective threading engagement with the inner-bundle external threads  292 . In the particular version shown, the housing internal threads  192  are formed (e.g., cut or molded) in the material (e.g., glass or plastic) from which the optics housing  100  is fabricated, although the optics housing  100  may be otherwise provided with internal threads  192 . For instance, a portion of the interior of the optics housing  100  may have affixed therein an internally threaded collar (not shown) along an interior surface of which the housing internal threads  192  are defined. 
         [0030]    In still further illustrative embodiments in which the optics housing  100  is either permanently attached or selectively attachable to the illuminable image bundle  200 , an optical element set  130  is selectively insertable into and out of the optics housing  100 . Accordingly, for instance, in an embodiment in which the optics housing  100  is permanently attached to the illuminable image bundle  200 , one set of optics can still be substituted for another in order to increase the overall versatility of the illuminable image bundle  200 . An illustrative, non-limiting example of such an embodiment is shown in  FIG. 5 . 
         [0031]    In the example of  FIG. 5 , an optical element set  130  comprising a lens doublet  132  including first and second lenses  132   a  and  132   b  is affixed within an optics casing  140 . The optics casing  140  has interior and exterior surfaces  142  and  144  and exhibits external dimensions that render it configured for the selective introduction into, and retention within, the optics channel  120 . In the version of  FIG. 5 , the exterior surface  144  of the optics casing  140  carries a set of external casing threads  146  configured for selective threading engagement with internal housing threads  119  depending from the inside surface  115   a  of the housing wall  114 . 
         [0032]    Depicted in  FIG. 5A  is another illustrative version in which an optical element set  130  is threadably retainable within the optics channel  120  of an optics housing  100 . In the illustrative version of  FIG. 5A , an optics casing  140  carrying a lens doublet  132  is slidably insertable into, and removable from, the optics channel  120  of the optics housing  100 . An optical-set retainer  150  depending from the housing wall  114  is configured for selective retention of the optics casing  140 . More specifically, in the case of  FIG. 5A , a threaded bore  117  extending through the housing wall  114  threadably retains a set screw  152 . With the optics casing  140  positioned as desired within the optics channel  120 , the set screw  152  may be threaded into the threaded bore  117  so as to selectively exert a retaining force against the exterior surface  144  of the optics casing  140 . Although the set screw  152  is not shown in a casing-retentive mode, the mode is readily comprehensible from the depiction of the  FIG. 5A  and associated description hereinabove. 
         [0033]    Various alternative embodiments provide for the selective coupling of an optical element set  130  to the illuminable image bundle  200  by means of threads. It will be appreciated that threaded surfaces must be at least arcuate, and are typically entirely cylindrical. However, alternative embodiments within the scope and contemplation of the invention include at least one of (i) an illuminable image bundle  200 , (ii) an optics housing, and (iii) an optics casing  140  that is other-than-cylindrical in cross-sectional geometry. In various such versions, at least one of the optics housing  100  and the optical element set  130  within the optics housing  100  may be selectively retained by set screws such as set screw  152  in  FIG. 5A  or devices other than threaded fasteners such, by way of non-limiting example, at least one of a (i) clip, (ii) snap and (iii) magnet. 
         [0034]    In still additional versions, it may be desirable to at least partially optically isolate at least one optical element of the optical element set  130  from the translucent material from with the housing wall  114  of the optics housing  110  is fabricated. It will be appreciated that the aforesaid optical isolation may be achieved by the inclusion of one or more opaque layers. Referring to  FIG. 5A , in one version, an opaque coating C O  is applied to the inside surface  115   a  of the housing wall  114 . Alternatively or in addition, an opaque coating is applied to at least one of the interior and exterior surfaces  142  and  144  of the optics casing  140  in those embodiments including and optics casing  140  such as, by way of example, the embodiment of  FIG. 5A . In yet other alternative versions including an optics casing  140 , the optics casing  140  is fabricated from an opaque material. 
         [0035]    The foregoing is considered to be illustrative of the principles of the invention. Furthermore, since modifications and changes to various aspects and implementations will occur to those skilled in the art without departing from the scope and spirit of the invention, it is to be understood that the foregoing does not limit the invention as expressed in the appended claims to the exact constructions, implementations and versions shown and described.