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US5418645A Expired / Lapsed US ⏱️ 0.0 years remaining

Endoscopic zoom lens

Assignee: KeyMed Medical & Industrial Equipment Ltd
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Filing: 1993-05-25
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Granted: 1995-05-23
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Expires: 2013-05-25
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Abstract

Abstract Apparatus (1) for use as an endoscope or borescope comprising an outer tube (2) having a distal end (3) which is insertable into an inaccessible location to be inspected and a proximal end (4) which is accessible to the user. A zoom lens is provided within the outer tube adjacent the distal end and is operable to focus an image with variable magnification at a focal plane within the outer tube. The zoom lens comprises an objective lens (7) which is fixed relative to the outer tube and two independently movable lenses (8,13). An elongate viewing means (43) is provided for viewing the image and extends through the outer tube from a location at the focal plane to a location proximal of the proximal end. A cam operated actuating means (29,21) is operable to move the movable lenses to change magnification and to synchronously move the viewing means relative to the objective lens to compensate for movement of the focal plane. Refocussing of the apparatus following adjustment of magnification is thereby carried out automatically.

Inventors

  • 👤 Philip M. Coath
  • 👤 Naeem A. Sayed

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 11:48
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/02; G02B7/04; G02B7/10; G02B23/00; G02B23/24; G02B23/2407; G02B23/2423; G02B23/243; G02B23/2438

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 161 words
Apparatus for use as an endoscope or borescope for inspection of an inaccessible object comprising an outer-tube having a distal end which is insertable in use into an inaccessible location and a proximal end which is accessible to the user, a zoom lens within the outer tube adjacent the distal end and operable to focus an image of the object with variable magnification at a focal plane within the outer tube, the zoom lens comprising an objective lens which is fixed relative to the outer tube and a plurality of independently movable lenses, the apparatus further comprising an elongate viewing means for viewing the image and extending through the outer tube from a location at or adjacent to the focal plane to a location proximal of the proximal end and actuating means operable to move the movable lenses to change magnification and to synchronously move the viewing means relative to the objective lens to compensate for movement of the focal plane.
Claim 2
Dependent Claim 161 words
Apparatus for use as an endoscope or borescope for inspection of an inaccessible object comprising an outer-tube having a distal end which is insertable in use into an inaccessible location and a proximal end which is accessible to the user, a zoom lens within the outer tube adjacent the distal end and operable to focus an image of the object with variable magnification at a focal plane within the outer tube, the zoom lens comprising an objective lens which is fixed relative to the outer tube and a plurality of independently movable lenses, the apparatus further comprising an elongate viewing means for viewing the image and extending through the outer tube from a location at or adjacent to the focal plane to a location proximal of the proximal end and actuating means operable to move the movable lenses to change magnification and to synchronously move the viewing means relative to the objective lens to compensate for movement of the focal plane.
Claim 3
Dependent Claim 49 words
Apparatus as claimed in claim 1 wherein each of the movable lenses is provided with a respective axially movable control tube to which they are fixedly mounted, the control tubes extending coaxially within the outer tube and being engaged at their respective proximal end portions by the actuator means.
Claim 4
Dependent Claim 31 words
Apparatus as claimed in claim 2 wherein the actuating means comprises a cam means providing movement of the movable lenses and the viewing means in response to movement of an actuator.
Claim 5
Dependent Claim 65 words
Apparatus as claimed in claim 3 wherein the cam means comprises a cylindrical member, the cylindrical member being provided with circumferentially extending cam slots engaged by respective radial projections of the control tubes, and the cam slots being profiled such that rotation of the cylindrical member relative to the outer tube provides axial displacement of the respective movable lenses in accordance with a predetermined characteristic.
Claim 6
Dependent Claim 46 words
Apparatus as claimed in claim 4 wherein the cylindrical member is provided with a further cam slot engaged by a cam follower connected to the viewing means to effect axial movement of the viewing means relative to the objective lens by rotation of the cylindrical member.
Claim 7
Dependent Claim 14 words
Apparatus as claimed in claim 1 wherein the zoom lens comprises two movable lenses.
Claim 8
Dependent Claim 73 words
Apparatus as claimed in claim 1 wherein the viewing means comprises a housing connected to the actuating means to provide axial movement synchronised with movement of the movable lenses, an image relaying means operable to relay an image from the focal plane of the zoom lens to the user and an adjustable coupling operatively connecting the housing to the image relaying means so as to provide focus adjustment accommodating variation in object range.
Claim 9
Dependent Claim 15 words
Apparatus as claimed in claim 7 wherein the image relaying means includes an optical relay.
Claim 10
Dependent Claim 55 words
Apparatus as claimed in claim 7 comprising an object range sensor operable to produce an electrical signal representative of the range of the object from the objective lens and an electromechanical focus actuator operable in response to the signal to focus on the object by movement of the image relaying means relative to the housing.

References Cited (Backward Citations)

US4312572A Cited
US4704007A Cited
US4448039A Cited
US4874232A Cited
US4976522A Cited
US5245475A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-05-22 1998-11-21 1999-05-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-05-22 2002-11-21 2003-05-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-05-22 2006-11-21 2007-05-23 $7700.00 Window Closed / Lapsed

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