Patent US3594071A successfully refreshed from Google Patents.
US3594071A
Expired / Lapsed
US
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Ophthalmoscopic camera
Assignee: Nikon Corp
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Filing: 1969-10-07
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Granted: 1971-07-20
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Expires: 1989-10-07
Abstract
Abstract An ophthalmoscopic camera is provided which can eliminate undesired light reflected from the cornea of an eye to be examined and the front and back surfaces of a front objective through which the illumination light passes by interposing a ring-shaped aperture between a plane reflecting mirror and a condenser lens arranged next to the reflecting mirror and a small shield between said condenser lens and the next condenser lens so as to shield a small area in the vicinity of and including the optical axis. The optical system for photography includes no such shield as described above and said photographic objective is of biconvex, thereby increasing the picture angle to 45*.
Inventors
- 👤 Hirokazu Okajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:46
CPC Classifications
A; A61; A61B; A61B3/00; A61B3/10; A61B3/14; A61B3/15; A61B3/156
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
320 words
A device for the photography of a fundus, particularly a retina of an eye, comprising, a main optical viewing system including a bi-convex photographic objective placed on an optical axis of the eye for forming an intermediate image of the retina, and an aperture stop placed at a position conjugate with the cornea of the eye with respect to the photographic objective; an illuminating system comprising a light source and an illuminating optical arrangement for projecting an image of said light source on the cornea of the eye sequentially including said photographic objective, and apertured inclined mirror placed between said photographic objective and said aperture stop for reflecting the illuminating light rays toward the optical axis of said objective and an optical system, whereby the optical axis of said optical system is arranged transversely to the axis of said photographic objective, said mirror is centrally positioned with respect to both the viewing system and optical system axes; said optical system further including first condenser lens proximate said light source followed by first and second positive lens means, a ring-shaped aperture having a central obscuring portion, said Ring-shaped aperture being provided on a surface of said second positive lens means and positioned with respect to said photographic objective and said photographic objective and said inclined mirror to produce an intermediate image of said ring aperture in substantial coincidence with said cornea, a center obscuring spot diaphragm placed on the optical axis of said optical system between said light source and said ring aperture, said spot diaphragm being provided on a surface of said first positive lens means with the lens elements of said illuminating optical arrangement so positioned as to form an intermediate image of said spot diaphragm on the rear surface of said photographic objective, whereby the curvature of the objective acts as a convex mirror for further forming said intermediate image of said spot diaphragm on said aperture stop.
Claim 2
Independent Claim
320 words
A device for the photography of a fundus, particularly a retina of an eye, comprising, a main optical viewing system including a bi-convex photographic objective placed on an optical axis of the eye for forming an intermediate image of the retina, and an aperture stop placed at a position conjugate with the cornea of the eye with respect to the photographic objective; an illuminating system comprising a light source and an illuminating optical arrangement for projecting an image of said light source on the cornea of the eye sequentially including said photographic objective, and apertured inclined mirror placed between said photographic objective and said aperture stop for reflecting the illuminating light rays toward the optical axis of said objective and an optical system, whereby the optical axis of said optical system is arranged transversely to the axis of said photographic objective, said mirror is centrally positioned with respect to both the viewing system and optical system axes; said optical system further including first condenser lens proximate said light source followed by first and second positive lens means, a ring-shaped aperture having a central obscuring portion, said Ring-shaped aperture being provided on a surface of said second positive lens means and positioned with respect to said photographic objective and said photographic objective and said inclined mirror to produce an intermediate image of said ring aperture in substantial coincidence with said cornea, a center obscuring spot diaphragm placed on the optical axis of said optical system between said light source and said ring aperture, said spot diaphragm being provided on a surface of said first positive lens means with the lens elements of said illuminating optical arrangement so positioned as to form an intermediate image of said spot diaphragm on the rear surface of said photographic objective, whereby the curvature of the objective acts as a convex mirror for further forming said intermediate image of said spot diaphragm on said aperture stop.
Claim 3
Dependent Claim
48 words
A device according to claim 1, wherein said first positive lens means is a planoconvex lens, said spot diaphragm being provided on the plane surface of said first positive lens means, said and said ring aperture being provided on the plane surface of said second positive lens means.
References Cited (Backward Citations)
US3089398A
Cited
US3259041A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |