Patent US4235540A successfully refreshed from Google Patents.
US4235540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Eye fundus camera having variable power photographing optical system
Assignee: Topcon Corp
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Filing: 1979-05-04
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Granted: 1980-11-25
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Expires: 1999-05-04
Abstract
Abstract Eye fundus camera including a photographing optical system comprised of an objective lens, an imaging lens and a magnification power changing lens device. The power changing lens device is movable in axial direction for effecting focusing.
Inventors
- 👤 Yoshihiko Hanamura
- 👤 Schinichi Nishimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:42
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/48; A; A61; A61B; A61B3/00; A61B3/10; A61B3/14
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
113 words
Eye fundus camera having a photographing optical system having a photographing optical axis and comprised of objective lens means, imaging lens means and magnification power changing lens means positioned between the objective lens means and the imaging lens means, said magnification power changing lens means being movable along the optical axis of the photographing optical system for focusing, said magnification power changing lens means comprising a plurality of lenses having different focal distances, said lenses being mounted on a member which is rotatable about an axis parallel with the photographing optical axis so that desired one of the lenses can be placed in the photographing optical path through rotation of the rotatable member.
Claim 2
Dependent Claim
113 words
Eye fundus camera having a photographing optical system having a photographing optical axis and comprised of objective lens means, imaging lens means and magnification power changing lens means positioned between the objective lens means and the imaging lens means, said magnification power changing lens means being movable along the optical axis of the photographing optical system for focusing, said magnification power changing lens means comprising a plurality of lenses having different focal distances, said lenses being mounted on a member which is rotatable about an axis parallel with the photographing optical axis so that desired one of the lenses can be placed in the photographing optical path through rotation of the rotatable member.
Claim 3
Dependent Claim
26 words
Eye fundus camera in accordance with claim 1 in which said rotatable member is mounted for movement along the photographing optical axis to thereby effect focusing.
Claim 4
Dependent Claim
140 words
Eye fundus camera having a photographing optical system having a photographing optical axis and comprised of objective lens means, imaging lens means and magnification power changing lens means positioned between the objective lens means and the imaging lens means, said magnification power changing lens means being movable along the optical axis of the photographing optical system for focusing, adjustable aperture means which is interconnected with the magnification power changing lens means so that the aperture means is adjusted in accordance with the magnification power of the lens means, said adjustable aperture means being comprised of a plurality of apertures of different diameters formed in a rotatable member which is interconnected with the magnification power changing lens means so that appropriate one of the apertures is inserted into the photographing optical path upon adjustment of the magnification power changing lens means.
Claim 5
Dependent Claim
140 words
Eye fundus camera having a photographing optical system having a photographing optical axis and comprised of objective lens means, imaging lens means and magnification power changing lens means positioned between the objective lens means and the imaging lens means, said magnification power changing lens means being movable along the optical axis of the photographing optical system for focusing, adjustable aperture means which is interconnected with the magnification power changing lens means so that the aperture means is adjusted in accordance with the magnification power of the lens means, said adjustable aperture means being comprised of a plurality of apertures of different diameters formed in a rotatable member which is interconnected with the magnification power changing lens means so that appropriate one of the apertures is inserted into the photographing optical path upon adjustment of the magnification power changing lens means.
Claim 6
Dependent Claim
95 words
Eye fundus camera having a photographing optical system having a photographing optical axis and comprised of objective lens means, imaging lens means and magnification power changing lens means positioned between the objective lens means and the imaging lens means, said magnification power changing lens means being movable along the optical axis of the photographing optical system for focusing, and an illumination system which is provided with adjustable aperture means interconnected with said magnification power changing lens means so that the illumination aperture is changed in accordance with the magnification power of the photographing optical system.
Claim 7
Dependent Claim
95 words
Eye fundus camera having a photographing optical system having a photographing optical axis and comprised of objective lens means, imaging lens means and magnification power changing lens means positioned between the objective lens means and the imaging lens means, said magnification power changing lens means being movable along the optical axis of the photographing optical system for focusing, and an illumination system which is provided with adjustable aperture means interconnected with said magnification power changing lens means so that the illumination aperture is changed in accordance with the magnification power of the photographing optical system.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-25 | 1984-05-26 | 1984-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-25 | 1988-05-26 | 1988-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-25 | 1992-05-26 | 1992-11-25 | $7700.00 | Window Closed / Lapsed |