Patent US3851954A successfully refreshed from Google Patents.
US3851954A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ophthalmoscopic camera
Assignee: Nikon Corp
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Filing: 1972-12-18
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Granted: 1974-12-03
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Expires: 1992-12-18
Abstract
Abstract An ophthalmoscopic camera capable of preventing unfavorable reflection of light on the corneal surface of an eye under examination, and on the front and rear surfaces of the crystalline lens even for an angle of view as wide as the order of 45*. The camera comprises a photographic optical system including an objective lens, an illuminating optical system including a light source, first and second condenser lenses, a mirror disposed at the intersection between the optical axes of the two optical systems and having an aperture for passing the image-forming light rays reflected from the fundus of an eye. A ring-shaped aperture substantially conjugate with the cornea with respect to the objective lens is provided in the illuminating optical system, and a center obscuring stop substantially conjugate with the median point between the front and rear surfaces of the crystalline lens with respect to the objective lens is also provided in the illuminating optical systems. An aperture stop is provided which is substantially conjugate with the median point between a formed image of the ring-shaped aperture and a formed image of the center obscuring stop with respect to the objective lens of the photographic system.
Inventors
- 👤 N Kato
- 👤 M Tao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:22
CPC Classifications
A; A61; A61B; A61B3/00; A61B3/10; A61B3/14; A61B3/15; A61B3/156
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
256 words
An ophthalmoscopic camera comprising: a photographic optical system including an objective lens for forming an image of the fundus of an eye; an illuminating optical system for illuminating the fundus of the eye including a light source, first and second condenser lenses; a mirror disposed at the intersection between the two optical axes of said photographic and illuminating optical systems for directing the light rays emanating from the light source into said fundus of the eye through said objective lens; said mirror having an aperture for passing therethrough the image-forming light rays reflected from the fundus of the eye; a ring-shaped aperture provided in said illuminating optical system and substantially conjugate with a cornea of the eye with respect to said objective lens for preventing the light rays reflected by the corneal surface from entering into the path of said image-forming rays; a center obscuring stop provided in said illuminating optical system and substantially conjugate with the median point between the front and rear surfaces of a crystalline lens of the eye with the respect to said objective lens for preventing the light rays reflected by the front and rear surfaces of the crystalline lens from entering into the path of the imageforming light rays; and an aperture stop for passing therethrough only said imageforming light rays passed through said aperture of said mirror, substantially conjugate with the median point between an image of said ring-shaped aperture and an image of said center obscuring stop formed by the objective lens with respect to said objective lens.
Claim 2
Dependent Claim
256 words
An ophthalmoscopic camera comprising: a photographic optical system including an objective lens for forming an image of the fundus of an eye; an illuminating optical system for illuminating the fundus of the eye including a light source, first and second condenser lenses; a mirror disposed at the intersection between the two optical axes of said photographic and illuminating optical systems for directing the light rays emanating from the light source into said fundus of the eye through said objective lens; said mirror having an aperture for passing therethrough the image-forming light rays reflected from the fundus of the eye; a ring-shaped aperture provided in said illuminating optical system and substantially conjugate with a cornea of the eye with respect to said objective lens for preventing the light rays reflected by the corneal surface from entering into the path of said image-forming rays; a center obscuring stop provided in said illuminating optical system and substantially conjugate with the median point between the front and rear surfaces of a crystalline lens of the eye with the respect to said objective lens for preventing the light rays reflected by the front and rear surfaces of the crystalline lens from entering into the path of the imageforming light rays; and an aperture stop for passing therethrough only said imageforming light rays passed through said aperture of said mirror, substantially conjugate with the median point between an image of said ring-shaped aperture and an image of said center obscuring stop formed by the objective lens with respect to said objective lens.
Claim 3
Dependent Claim
21 words
An ophthalmoscopic camera according to claim 1, wherein said ring-shaped aperture is provided on a surface of said first condenser lens.
Claim 4
Dependent Claim
22 words
An opthalmoscopic camera according to claim 1, wherein said center obscuring stop is provided on a surface of said second condenser lens.
Claim 5
Dependent Claim
283 words
An ophthalmoscopic camera comprising: a photographic optical system including an objective lens for forming an image of the fundus of an eye; an illuminating optical system for illuminating the fundus of the eye including a light source, first and second condenser lenses; a mirror disposed at the intersection between the two optical axes of said photographic and illuminating optical systems for directing the light rays emanating from the light source into said fundus of the eye through said objective lens; said mirror having an aperture for passing therethrough the image forming light rays reflected from the fundus of the eye; a ring-shaped aperture provided on a surface of said first condenser lens and substantially conjugate with a cornea of the eye with respect to said objective lens for preventing the light rays reflected by the cornea surface from entering into the path of said image-forming light rays; a center obscuring stop provided on a surface of said second condenser lens and substantially conjugate with the front surface of a crystalline lens of the eye with respect to said objective lens for preventing the light rays reflected by the front surface of the crystalline lens from entering into the path of the image forming light rays; a first aperture stop for passing therethrough only said image-forming light rays passed through the aperture of said mirror, substantially conjugate with the image of the center obscuring stop formed by the objective lens with respect to said objective lens; and a second aperture stop for passing therethrough only said image-forming light rays passed through said first aperture stop, conjugate with the image of the ring-shaped aperture formed by the objective lens with respect to said objective lens.
Claim 6
Dependent Claim
283 words
An ophthalmoscopic camera comprising: a photographic optical system including an objective lens for forming an image of the fundus of an eye; an illuminating optical system for illuminating the fundus of the eye including a light source, first and second condenser lenses; a mirror disposed at the intersection between the two optical axes of said photographic and illuminating optical systems for directing the light rays emanating from the light source into said fundus of the eye through said objective lens; said mirror having an aperture for passing therethrough the image forming light rays reflected from the fundus of the eye; a ring-shaped aperture provided on a surface of said first condenser lens and substantially conjugate with a cornea of the eye with respect to said objective lens for preventing the light rays reflected by the cornea surface from entering into the path of said image-forming light rays; a center obscuring stop provided on a surface of said second condenser lens and substantially conjugate with the front surface of a crystalline lens of the eye with respect to said objective lens for preventing the light rays reflected by the front surface of the crystalline lens from entering into the path of the image forming light rays; a first aperture stop for passing therethrough only said image-forming light rays passed through the aperture of said mirror, substantially conjugate with the image of the center obscuring stop formed by the objective lens with respect to said objective lens; and a second aperture stop for passing therethrough only said image-forming light rays passed through said first aperture stop, conjugate with the image of the ring-shaped aperture formed by the objective lens with respect to said objective lens.
References Cited (Backward Citations)
US3594071A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |