Portable field inspection microscope for inspecting a butt end of a cylindrical object, such as a fiber optics cable

• US 4,595,265 A
• Filed: 04/04/1983
• Issued: 06/17/1986
• Est. Priority Date: 04/04/1983
• Status: Expired due to Fees

• Current Assignee: Herbert D. Barham, R. W. Hodgson
• Original Assignee: Herbert D. Barham, R. W. Hodgson
• Inventors: Hodgson, R. W., Barham, Herbert D.
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Lewis, David
• Application Number:
  US06/481,854
• Time in Patent Office: 1,170 Days
• Field of Search: 350/523, 350/525, 350/529, 350/507, 350/410, 350/521, 350/518, 350/530, 350/527, 356/237
• US Class Current: 359/383
• CPC Class Codes: G02B 21/0008 Microscopes having a simple construction, e.g. portable microscopes
• CPC Class Codes: G02B 21/06 Means for illuminating specimens
• CPC Class Codes: G02B 6/3803 Adjustment or alignment devices for alignment prior to splicing

Abstract

An improved portable field inspection microscope intended primarily for, but not in all cases limited to, use in inspecting butt ends of fiber optics cables, or other similar cylindrical objects, and including a receiver, holder and positioner adapted to receive such a butt end of a fiber optics cable, or the like, and to position same coincident with a selected butt-end-surface-viewing plane, which may also be considered as a microscope focusing plane, which lies appropriately forwardly of a microscope optical-path-defining longitudinal cylindrical inner chamber in a small portable housing and which not only carries said receiver, holder and positioner at a forward location, but intermediately carries microscope objective lens mounting apparatus and a microscope objective lens assembly for focusing on said focusing plane, and with the housing also being further rearwardly provided with microscope eyepiece lens mounting apparatus and an eyepiece lens assembly longitudinally adjustably carried for focusing on, and providing a desired degree of apparent visual image magnification of, a butt end surface of a fiber optics cable, or the like, which is being viewed and inspected while received, held, and positioned in the focusing plane. The housing is also provided with bright field illuminator apparatus and dark field illuminator apparatus and controllably operable switch and battery assembly structures for providing either bright field illumination of directly forwardly incident light and directly rearwardly reflected reverse light, or dark field illumination of annularly arranged sharply angularly directed incident light and consequent sharply angularly reflected and effectively "lost" reverse light for dark field illumination of a butt end surface positioned in the focusing plane for viewing and inspection.

Claims

1. A portable field inspection microscope for inspecting a butt end surface of a cylindrical object, such as a fiber optics cable, having both a butt end and a butt-end-surface, which is to be inspected, comprising:

a housing means provided with a butt-end-receiver, holder and positioner for receiving and holding and positioning a butt end, and a butt-end-surface of a cylindrical object, such as a fiber optics cable, in a location and position such as to cause the butt-end-surface to be coincident with a selected butt-end-surface viewing-focusing plane, said housing means being provided with an optical-path defining a longitudinal inner chamber means having a corresponding longitudinal optical axis centered along the length of said chamber and optically communicating at one front end with said butt-end receiver, holder and positioner, and being intermediately provided with objective lens mounting means and microscope objective lens means optically aligned with said receiver, holder and positioner focusable on the focusing plane and any cylindrical object'"'"'s butt-end-surface coincident with the focusing plane;

said optical-path-defining chamber means being provided adjacent to an opposite rear end of said chamber means with eyepiece lens mounting means and eyepiece lens means longitudinally adjustably carried by said eyepiece lens mounting means for focusing and providing a desired degree of apparent visual image magnification of a butt end surface of a cylindrical object being viewed and inspected while received, held and positioned in the focusing plane;

said objective lens means, said objective lens mounting means, said eyepiece lens means, said eyepiece lens mounting means, and said optical-path-defining chamber means, together, effectively defining an inspection microscope effectively provided with focusing means comprising means for manually adjusting the relative longitudinal spacings between various of said lens means relative to each other and relative to the focusing plane and said butt-end-surface of said butt end of said cylindrical object, such as said butt-end-surface of said butt end of said fiber optics cable, co-planar with the focusing plane;

said optical-path-defining longitudinal inner chamber means of said housing means being provided with and carrying illuminator means within said chamber means for providing, in a symmetrically positioned manner, within the optical-path-defining chamber means, illuminating light directed forwardly, said illuminator means being carried centrally by and in said optical-path-defining chamber means and being provided with separate, transversely connectable, controllably operable, electrical energizer means for controllably energizing and deenergizing said illuminator means;

said illuminator means carried within said optical-path-defining longitudinal inner chamber means of said housing means comprising a bright field illuminator means substantially centrally positioned within said optical-path-defining chamber means, being located and directed for injecting illuminating light into the optical path along an optical axis of said optical-path-defining chamber means in a manner such as to redirect same forwardly and longitudinally along said optical path through said objective lens means toward said focusing plane in a direction substantially normal to said focusing plane for causing substantially directly reversed rearward reflection of light from a butt-end-surface being viewed and inspected in what is termed a bright field illuminated manner;

said illuminator means carried within said optical-path-defining longitudinal inner chamber means of said housing further comprising a dark field illuminator means substantially concentrically positioned within said optical-path-defining chamber means and concentrically positioned around a central optical axis extending the length of said optical-path-defining chamber means and being located and directed for injecting obliquely directed substantially annularly arranged and concentrically positioned dark field illuminating light forwardly convergingly along said optical-path-defining chamber means just rearwardly of said focusing plane and directed sharply transversely convergingly centrally and forwardly angularly onto the focusing plane, and onto any cylindrical object'"'"'s butt-end-surface co-planar with the focusing plane, for providing maximum oblique transversely-directed dark field illumination of the butt-end-surface being viewed and inspected in the focusing plane for causing rearward light reflection to occur only from surface irregularities and discontinuities on such a butt-end-surface being viewed and inspected while reflecting all other angularly incident light angularly impinging upon such a butt-end-surface in an angular reflected direction such as to be incapable of being returned to the eyepiece lens means and thus providing what is herein termed dark field illumination of such a butt-end-surface being inspected and viewed in the focusing plane, said angularly incident dark-field-illuminating light, and the means producing and angularly directing the angularly incident dark-field-illuminating light being so arranged, directed, and located relative to the focusing plane and relative to a front end of the centrally positioned objective lens means, as to cause rearwardly angularly directed dark field light reflections reflected from a butt-end-surface portion normal to the longitudinal optical axis to rearwardly and outwardly angularly diverge from the central longitudinal optical axis to an extent such as to be laterally displaced sufficiently to entirely miss, and to entirely laterally by-pass, the centrally symmetrically positioned objective lens means which optically encompasses a narrow central area of the chamber means immediately around the longitudinal optical axis only;

said focusing means comprising a focusing assembly taking the form of an outer spirally grooved sleeve, provided with and defining an outer spiral groove, an inner longitudinally grooved sleeve, provided with and defining an inner longitudinal groove, and a short transverse fixed pin carried by said housing means and having a fixed end projecting into said grooves in both of said sleeves whereby relative rotation of said outer spirally grooved sleeve with respect to said fixed pin end will effectively produce longitudinal focusing movement of the pair of said sleeves and said butt end, and said corresponding butt-end-surface, of said cylindrical object, such as said butt-end-surface of said fiber optics cable, otherwise fixedly carried by said focusing assembly at a forward center portion of said focusing assembly concentric with the longitudinal optical axis of said chamber means, said focusing assembly being substantially centrally provided with controllably operable cable-holding means for receiving and being manually controllably firmly fastened around an outer cylindrical surface adjacent to a butt end of a cylindrical object, such as fiber optics cable.

2. A portable field inspection microscope as defined in claim 1, wherein said dark field illuminator means comprises an annularly arranged effective ring light source producing and forwardly directing an effective annular ring of light positioned rearwardly of said focusing plane and directed forwardly toward said focusing plane and further provided with forwardly converging effective mirror means terminating in a frontally-positioned circular aperture and annular-slot-defining means for inwardly and obliquely angularly reflecting an annular ring of light forwardly emitted by said effective ring light source.

3. A portable field inspection microscope as defined in claim 2, wherein said annular-slot-defining means and said forwardly converging mirror means are controllably longitudinally adjustably mounted for controllable longitudinal shifting of the plane of maximum concentration of said obliquely angularly directed dark field illumination rays of light so as to be coplanar and coincident with said focusing plane.

4. A portable field inspection microscope as defined in claim 1, wherein said bright field illuminator means comprises transversely directed lamp means, and effective focusing means for said lamp means positioned immediately transversely adjacent to the longitudinal optical axis of the optical path defined by said optical-path-defining chamber means and adjacent to, and just rearwardly of, said objective lens means, an angularly positioned partially light-transmissive and partially light-reflective mirror means operable to redirect a quantity of bright-field light from said bright field illuminator means lamp means directly forwardly toward the focusing plane in a manner substantially normal to the focusing plane and cooperable to cause at least a portion of said forwardly directed bright field light to impinge upon a butt end surface being inspected and viewed in a bright field illuminated manner to be directly reflected backwardly from unmarred portions of such a butt-end-surface through said light-transmissive mirror means to said eyepiece means for forming an enlarged image of such a butt-end-surface effectively illuminated in said bright-field illuminated manner.