SPOTSIZE ADAPTER FOR FIBER OPTIC COUPLING

Abstract: A spotsize adapter (10) for fiber optic coupling. The spotsize adapter (10) converts the spotsize utilized with a fiber optic bundle (14) of a 5 millimeter fiber optic cable (12) into a spotsize adapted for a fiber optic bundle (14) of a 3.0 or 3.5 millimeter fiber optic cable (12). The spotsize is adapted by way of a bi-convex lens (20) which may be aspheric, positioned within the spotsize adapter (10). Accordingly, a different size cable can be used with an existing illumination system, resulting in increased comfort for the user and in increased amount of light presented to an instrument attached to the other end of the fiber optic cable (12).

Description: TITLE OF THE INVENTION Spotsize Adapter for Fiber Optic Coupling CROSS REFERENCE TO RELATED APPLICATIONS This application is based on Provisional Application serial number 60/012,718 filed March 4, 1996. BACKGROUND OF THE INVENTION A headlamp assembly for a surgeon is typically connected to an illumination source through for example a 5 millimeter fiber optic cable. The illumination source includes a projection lamp having a filament which produces light. The light is then adjusted through a condenser assembly to form a beam of light which has a spotsize adapted for the fiber optic bundle of the 5 millimeter fiber optic cable. A socket is included as part of the illumination source and permits a first end of the 5 millimeter fiber optic cable to be inserted and removed from the illumination source. The 5 millimeter fiber optic cable is coupled at its second end to a headmounted projection module for illuminating a field of view for a surgeon. In some environments it is desirable to utilize a fiber optic cable which is smaller than a 5 millimeter fiber optic cable. BRIEF SUMMARY OF THE INVENTION A spotsize adapter for fiber optic coupling is presented. The spotsize adapter converts the spotsize utilized with the fiber optic bundle of a first size fiber optic cable into a spotsize adapted for the fiber optic bundle of a second size fiber optic cable. The spotsize is adapted by way of a bi-convex lens positioned within the spotsize adapter. The lens may be aspheric on one or both sides The first end of the adapter fits into the standard socket for the first size fiber optic cable and the second end receives the second size fiber optic cable. In this manner a different size cable can be used with an existing illumination system, resulting in increased comfort for the user and an increased amount of light presented to an instrument attached to the distal end of the fiber optic cable. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which: Fig. 1 is a cross sectional view of a prior art illumination source coupled to a five millimeter fiber optic cable; Fig. 2 is an exploded isometric view of the spotsize adapter of the present invention; Fig. 3 is a cross-sectional view of an illumination source coupled to the spotsize adapter of the present invention; and Fig. 4 is a diagram of a headmounted headlamp including the smaller sized fiber optic cable. DETAILED DESCRIPTION OF THE INVENTION Referring to Fig. 1, a prior art illumination source 26 is shown. A 5 millimeter fiber optic cable 40 is coupled to socket 24 of the illumination source 26. The illumination source 26 includes a projection lamp 28 having a filament 30. An optical system 32, such as a condenser, adapts the light emitted by the projection lamp 28 to a beam of light having a spotsize compatible with the fiber optic bundle 44 of the 5 millimeter fiber optic cable 40. The fiber optic cable 40 includes a jacket 42 which is relatively stiff and unwieldy as compared to fiber optic cables of different sizes. Referring now to Figs. 2 and 3, a spotsize adapter 10 is shown. While this embodiment involves reducing the spotsize adapted for a 5 millimeter fiber optic cable to a spotsize adapted for a 3.0 or 3.5 millimeter fiber optic cable, it should be appreciated that other size fiber optic cables could also be utilized, as could an embodiment involving increasing the spotsize. The spotsize adapter 10 comprises a cylindrical adapter housing 22 having a central bore 42 disposed therethrough. The adapter housing 22 has an outside diameter approximately equal to the outside diameter of, for example, a 5 millimeter fiber optic cable. As such, a first end 40 of the adapter housing 22 can be coupled to the socket 24 of the illumination source 26. The adapter housing 22 has a lens 20 disposed within the central bore 42. Lens 20 in this embodiment is an aspheric bi-convex lens. In this embodiment a ferrule 18 is included as part of the adapter 10, however in alternate embodiments the ferrule need not be part of the adapter or the ferrule may be attached to the end of the fiber optic cable and inserted into and removed from the adapter. The ferrule 18 is positioned such that its first end 43 is inserted into the second end 41 of the adapter housing 22. The ferrule 18 includes a central bore 44 which is adapted to receive the fiber optic bundle 14 of a 3.0 or 3.5 millimeter fiber optic cable 12 partially therein. The smaller fiber optic cable 12 includes a jacket 16 which is smaller and more flexible, and thus easier to maneuver, than that of the 5 millimeter fiber optic cable described above. Typically, the ferrule 18 forms a termination of cable 12. In operation, light provided by filament 30 of projection lamp 28 is adapted by optical system 32 to provide a beam of light having a spotsize compatible with the optical fiber bundle of a 5 millimeter fiber optic cable. Optical system 32 comprises one or more planar/convex lenses. Bi- convex lens 20 converts the beam of light having the spotsize adapted for the fiber optic bundle of the 5 millimeter cable to a beam of light having a spotsize compatible with the fiber optic bundle 14 of a 3.0 millimeter fiber optic cable or a 3.5 millimeter fiber optic cable 12. A first end of the fiber optic cable 12 is in optical communication with the beam of light exiting lens 20, and thus provides light to an instrument (not shown) coupled to a second end of the fiber optic cable 12. The lens 20 is anti-reflective (AR) coated and has both convex surfaces aspherically formed to minimize aberrations for the preferred application of supplying light to surgeons headlamps 34 supported on headbands 36 and used to illuminate surgeons work areas, as shown in Fig. 4. The numerical aperture of the beam applied from the lens 20 is optimized to the numerical aperture of the fiber bundle 14. The lens 20 is located at a distance relative to the condenser 32 in order to capture a maximum amount of the illumination from the condenser 32 and thus enhances the amount of light available at the headlamp 34 compared to prior art designs. Having described preferred embodiments of the invention it will now become apparent to those of ordinary skill in the art that other embodiments incorporating these concepts may be used. Accordingly, it is submitted that the invention should not be limited to the described embodiments but rather should be limited only by the spirit and scope of the appended claims.

Claims: * CLAIMS We claim: 1. A spotsize adapter comprising: an adapter housing having a first end, a second end and a central bore disposed therethrough; and a lens disposed within the central bore of said adapter housing for adapting the spotsize of a beam of light from a first spotsize adapted for a fiber optic bundle of a first size fiber optic cable to a second spotsize adapted for a fiber optic bundle of a second size fiber optic cable. 2. The spotsize adapter of claim 1 wherein said lens is bi¬ convex. 3. The spotsize adapter of claim 2 wherein a front surface of said bi-convex lens and/or a rear surface of said bi¬ convex lens are aspheric. 4. The spotsize adapter of claim 1 wherein said lens has an anti-reflective coating. 5. The spotsize adapter of claim 1 wherein said first size fiber optic cable comprises a 5 millimeter fiber optic cable. 6. The spotsize adapter of claim 1 wherein said second size fiber optic cable is selected from the group consisting of a 3.0 millimeter cable and a 3.5 millimeter cable. 7. The spotsize adapter of claim 1 wherein said adapter housing is cylindrical and has an outside diameter approximately equal to the outside diameter of the first size fiber optic cable. 8. The spotsize adapter of claim 1 further comprising a ferrule having a first end, a second end and a central bore disposed therethrough, partially disposed within the second end of said adapter housing. 9. The spotsize adapter of claim 8 wherein the bore of said ferrule is adapted to receive the fiber optic bundle of the second size fiber optic cable therein. 10. An illumination system comprising: a housing defining an interior space; a projection lamp having a filament, disposed within the interior space of said housing; an optical system disposed within the interior space of said housing, in optical communication with said projection 1amp; a socket disposed within said housing ad acent said interior space of said housing; and a spotsize adapter comprising: an adapter housing having a first end, a second end and a central bore disposed therethrough; and a lens disposed within the central bore of said adapter housing for adapting a spotsize of a beam of light from a first spotsize adapted for a fiber optic bundle of a first size fiber optic cable to a second spotsize adapted for a fiber optic bundle of a second size fiber optic cable; wherein the first end of said adapter is disposed within said socket . 11. The illumination system of claim 10 wherein said optical system comprises a condenser. 12. The illumination system of claim 10 wherein said optical system comprises at least one convex lens. 13. The illumination system of claim 10 wherein said lens is bi-convex. 14. The illumination system of claim 13 wherein a front surface of said lens and a rear surface of said lens are aspheric. 15. The illumination system of claim 10 wherein said lens has an anti-reflective coating. 16. The illumination system of claim 10 wherein said first size fiber optic cable comprises a 5 millimeter fiber optic cable. 17. The illumination system of claim 10 wherein said second size fiber optic cable is selected from the group consisting of a 3.0 millimeter fiber optic cable and a 3.5 millimeter fiber optic cable. 18. The illumination system of claim 10 wherein said adapter housing is cylindrical and has an outside diameter approximately equal to the outside diameter of the first size fiber optic cable. 19. The illumination system of claim 10 wherein said adapter further comprises a ferrule having a first end, a second end and a central bore disposed therethrough, partially disposed within the second end of said adapter housing. 20. The illumination system of claim 19 wherein the bore of said ferrule is adapted to receive the fiber optic bundle of the second size fiber optic cable therein. 21. The illumination system of claim 10 further comprising a fiber optic cable having a first end, a second end, a fiber optic bundle, and a ferrule coupled to the first end of said fiber optic cable, said ferrule adapted to couple with said adapter. 22. The illumination system of claim 21 wherein said fiber optic cable is selected from the group consisting of a 3.0 millimeter fiber optic cable and a 3.5 millimeter fiber optic cable. 23. The illumination system of claim 19 further comprising a fiber optic cable having a first end, a second end and a fiber optic bundle, wherein the first end is partially disposed within the central bore of said ferrule. 24. The illumination system of claim 23 wherein said fiber optic cable is selected from the group consisting of a 3.0 millimeter fiber optic cable and a 3.5 millimeter fiber optic cable. 25. The illumination system of claim 21 wherein the second end of said fiber optic cable is coupled to an instrument. 26. The illumination system of claim 23 wherein the second end of said fiber optic cable is coupled to an instrument. 27. The illumination system of claim 25 wherein said instrument comprises a headlamp. 28. The illumination system of claim 26 wherein said instrument comprises a headlamp.

Inventors: BHATTACHARYA RAM, TALBOT CINDY M, BHATTACHARYA, RAM, TALBOT, CINDY, M.
Applicants: LUXTEC CORP, LUXTEC CORPORATION
Application year: 1997
Main classification: G02B6
IPC codes: F21L4, F21S2, F21V8, G02B6