Illuminable image-conducting optical assembly including light-conductive optics housing for creating an illuminating halo

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 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.

BACKGROUND

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 inFIG. 1A. Typically, a device such as that shown inFIG. 1Ais 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 ofFIG. 1Bare fabricated. In the bundle ofFIG. 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.

Difficulties abound in the fabrication of illuminable image-transporting fiber bundles of the general configuration shown inFIG. 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.

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

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.

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.

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.

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.

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.

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.

Representative, non-limiting embodiments are more completely described and depicted in the following detailed description and the accompanying drawings.

DETAILED DESCRIPTION

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.

In a first illustrative configuration shown inFIGS. 2,2A and2B, a cylindrical light-conductive optics housing100extends between open first and second housing ends110and112. A housing wall114extends between the first and second housing ends110and112and includes a light-entrance end116and a light-exit end118that coincide with, respectively, the first and second housing ends110and112. Moreover, the housing wall114includes inside and outside surfaces115aand115bextending between the light-entrance and light-exit ends116and118. The housing wall114defines an optics channel120that is bounded by the inside surface115aand configured to house an optical element set130including at least one optical element. In the illustrative embodiment ofFIG. 2, the optical element set130comprises a lens doublet132including first and second lenses132aand132b. However, it is to be understood that the optical element set130in various versions may include in addition to, or instead of, either or both of first and second lenses132aand132b, 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 wall114is translucent such that light introduced into the housing wall114through the light-entrance end116is transmitted through the housing wall114for emission from the light-exit end118.

Referring still toFIG. 2, the optics housing100, and the optical element set130housed thereby, are in optical communication (i.e., optically coupled) with an illuminable image-transporting optical fiber bundle200which, for convenience and brevity, is alternatively referred to as illuminable image bundle200or by some similar designation. The illuminable image bundle200includes an inner image-conducting bundle210having first and second image-bundle ends212and214and a plurality of light-conductive imaging conduits220(e.g., optical fibers) extending between the first and second image-bundle ends212and214. Referring toFIGS. 2 and 2B, each imaging conduit220includes first and second ends222and224and comprises an optically transmissive core230having an imaging-core refractive index. Each core230is surrounded by a cladding material232having an imaging-cladding refractive index lower than the imaging-core refractive index such that light propagates through the imaging conduit220by total internal reflection in accordance with principles well-known to those of ordinary skill in the related art. The first ends222of the imaging conduits220terminate at, and combine to define, an image-input face216at the first image-bundle end212. Analogously, the second ends224of the imaging conduits220terminate at, and define, an image-output face218at the second image-bundle end214.

Disposed circumferentially about the image-conducting bundle210is a plurality of bundled illumination conduits250(e.g., optical fibers). Each illumination conduit250includes a first, light-collection end252and a second, light-emission end254opposite the light-collection end252. In alternative versions, the light-collection ends252of the illumination conduits250collect light from a single remote light source (not shown) or from multiple remote light sources (not shown). Plural light-emission ends254combine to define a light-output face258. In the particular illuminable image bundle200ofFIG. 2, the light-output face258is annularly disposed about the first ends222of the imaging conduits220such that the light-output face258and the image-input face216form a first common face270. Moreover, in the particular version ofFIG. 2, the first common face270is 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 EO) to and between the light-output face258of the illuminable image bundle200and the light-entrance end116of the optics housing100.

Depicted inFIGS. 3 and 3Ais an embodiment alternative to that ofFIGS. 2,2A and2B. In most of its aspects, the version ofFIGS. 3 and 3Aincludes elements analogous to those of the version ofFIGS. 2-2Band, therefore, the same reference characters are used to identify like elements associated with the two alternative versions. In the version ofFIGS. 3 and 3A, the image-input face216of the image-conducting bundle210does not define with the light-output face258a common face, such as common face270shown inFIG. 2. More specifically, while in the version ofFIGS. 3 and 3Athe light-emission ends254of the illumination conduits250define a light-output face258that is annularly disposed about the image-conducting bundle210, the light-output face258is recessed by a distance DR relative to the image-input face216such that a stepped shoulder272separates the image-input face216and the light-output face258. As shown inFIG. 3, a configuration in which the image-input face216extends beyond the light-output face258facilitates the protrusion of a portion of the length of the image-conducting bundle210into the optics channel120of a compatibly dimensioned optics housing100. Shown inFIG. 3Ais a view into cross-sectional plane IIIA ofFIG. 3, which is taken along a portion of the image-conducting bundle210that protrudes into the optic channel120and shows that, along this protruding portion, the image-conducting bundle210is surrounded by the optics housing100. In a version such as that ofFIG. 3, an adhesive such as epoxy E, for example, may be applied to a portion of the stepped shoulder272extending along overlapping portions of the lengths of the image-conducting bundle210and the optics housing100to retain the optics housing100in a fixed position relative to the illuminable image bundle200. In addition to contributing to overall structural integrity of the joint between the optics housing100and the illuminable image bundle200, stepped shoulder272, by providing a length-wise extending portion along which to apply an adhesive, obviates the need to apply adhesive to the light-entrance end116of the housing wall114and the light-output face258, thereby preserving the integrity of light transmission at the light interface ILdefined between the light-entrance end116and the light-output face258.

Referring toFIGS. 4A and 4B, alternative versions are shown in which the optics housing100is threadably coupled to the illuminable image bundle200. One advantage envisioned in association with such embodiments is the ability to selectively remove and attach different optics housings100retaining optical element sets130with different optical elements to the illuminable image bundle200. The illustrative version ofFIG. 4Ais in most major respects similar to that ofFIG. 2and, therefore, like reference characters are used to refer to analogous elements. In the version ofFIG. 4A, however, a portion of the length of the illuminable image bundle200, beginning at the light output face258, is provided with a first external-thread set282. In the particular version depicted, the external-thread set282is formed on a first threaded collar280that is annularly affixed about a portion of the length of the illuminable image bundle200. However, it will be appreciated that the illuminable image bundle200may be otherwise provided with an external-thread set282. Similarly, a portion of the length of the optics housing100, beginning at the light-entrance end116, and extending toward the light-exit end118, has affixed thereabout a second threaded collar180that carries a second external-thread set182. The optics housing100and illuminable image bundle200are selectively coupled by an internally-threaded coupler300that has defined therein a first internal-thread set302ainto which threads of the first external-thread set282are threaded and a second internal-thread set302binto which threads of the second external-thread set182are threaded. It is to be understood that alternative versions may include an internally-threaded coupler300that is permanently affixed (e.g. and not threaded) about one of the illuminable image bundle200and the optics housing100, while the other of the optics housing100and the image bundle200is threaded into the threaded coupler300.

Referring toFIG. 4B, a version including a stepped shoulder272such as that exhibited by the version ofFIG. 3is shown. To the extent that elements of the versions ofFIGS. 4B and 3are analogous, they are identified by like reference characters. Referring now toFIG. 4B, at least a portion of the stepped shoulder272extending along a portion of the length of the inner image-conducting bundle210carries inner-bundle external threads292. In the particular version shown, the inner-bundle external threads292are defined about the exterior surface of a inner-bundle threaded collar290that is affixed about that portion of the inner bundle210protruding beyond the light-output face258. However, it will be appreciated that the portion of the inner bundle210protruding beyond the light-output face258may be otherwise provided with inner-bundle external threads292. Beginning adjacent the light-entrance end116, a portion along the length of the optics housing100includes housing internal threads192configured for selective threading engagement with the inner-bundle external threads292. In the particular version shown, the housing internal threads192are formed (e.g., cut or molded) in the material (e.g., glass or plastic) from which the optics housing100is fabricated, although the optics housing100may be otherwise provided with internal threads192. For instance, a portion of the interior of the optics housing100may have affixed therein an internally threaded collar (not shown) along an interior surface of which the housing internal threads192are defined.

In still further illustrative embodiments in which the optics housing100is either permanently attached or selectively attachable to the illuminable image bundle200, an optical element set130is selectively insertable into and out of the optics housing100. Accordingly, for instance, in an embodiment in which the optics housing100is permanently attached to the illuminable image bundle200, one set of optics can still be substituted for another in order to increase the overall versatility of the illuminable image bundle200. An illustrative, non-limiting example of such an embodiment is shown inFIG. 5.

In the example ofFIG. 5, an optical element set130comprising a lens doublet132including first and second lenses132aand132bis affixed within an optics casing140. The optics casing140has interior and exterior surfaces142and144and exhibits external dimensions that render it configured for the selective introduction into, and retention within, the optics channel120. In the version ofFIG. 5, the exterior surface144of the optics casing140carries a set of external casing threads146configured for selective threading engagement with internal housing threads119depending from the inside surface115aof the housing wall114.

Depicted inFIG. 5Ais another illustrative version in which an optical element set130is threadably retainable within the optics channel120of an optics housing100. In the illustrative version ofFIG. 5A, an optics casing140carrying a lens doublet132is slidably insertable into, and removable from, the optics channel120of the optics housing100. An optical-set retainer150depending from the housing wall114is configured for selective retention of the optics casing140. More specifically, in the case ofFIG. 5A, a threaded bore117extending through the housing wall114threadably retains a set screw152. With the optics casing140positioned as desired within the optics channel120, the set screw152may be threaded into the threaded bore117so as to selectively exert a retaining force against the exterior surface144of the optics casing140. Although the set screw152is not shown in a casing-retentive mode, the mode is readily comprehensible from the depiction of theFIG. 5Aand associated description hereinabove.

Various alternative embodiments provide for the selective coupling of an optical element set130to the illuminable image bundle200by 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 bundle200, (ii) an optics housing, and (iii) an optics casing140that is other-than-cylindrical in cross-sectional geometry. In various such versions, at least one of the optics housing100and the optical element set130within the optics housing100may be selectively retained by set screws such as set screw152inFIG. 5Aor devices other than threaded fasteners such, by way of non-limiting example, at least one of a (i) clip, (ii) snap and (iii) magnet.

In still additional versions, it may be desirable to at least partially optically isolate at least one optical element of the optical element set130from the translucent material from with the housing wall114of the optics housing110is fabricated. It will be appreciated that the aforesaid optical isolation may be achieved by the inclusion of one or more opaque layers. Referring toFIG. 5A, in one version, an opaque coating COis applied to the inside surface115aof the housing wall114. Alternatively or in addition, an opaque coating is applied to at least one of the interior and exterior surfaces142and144of the optics casing140in those embodiments including and optics casing140such as, by way of example, the embodiment ofFIG. 5A. In yet other alternative versions including an optics casing140, the optics casing140is fabricated from an opaque material.

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.