US4679919A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ophthalmic photographic apparatus
Assignee: Canon Inc
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Filing: 1986-07-15
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Granted: 1987-07-14
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Expires: 2006-07-15
Abstract
Abstract In an opthalmic photographing apparatus, capable of photographing the fundus of an eye to be examined at a variable magnification, being provided with a ring slit in an illuminating optical path at a position substantially conjugate with the front-eye-part and being further provided with a baffle at a position substantially conjugate with the crystalline lens, the slit width of a ring slit image projected onto the eye to be examined and further the size of a baffle image are variable with a magnification change.
Inventors
- 👤 Yuji Itoh
- 👤 Junichi Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:43
CPC Classifications
A; A61; A61B; A61B3/00; A61B3/10; A61B3/14
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
85 words
An opthalmic photographing apparatus having: photographing means for photographing the fundus of an eye to be examined at a variable magnification; a ring slit having an outside diameter provided in an illuminating optical path for illuminating the fundus of the eye at a position substantially conjugate with the front-eye-part; and means for varying the slit width of a ring slit image projected onto the eye to be examined, with a magnification change such that the outside diameter of the ring slit image is not varied.
Claim 2
Dependent Claim
85 words
An opthalmic photographing apparatus having: photographing means for photographing the fundus of an eye to be examined at a variable magnification; a ring slit having an outside diameter provided in an illuminating optical path for illuminating the fundus of the eye at a position substantially conjugate with the front-eye-part; and means for varying the slit width of a ring slit image projected onto the eye to be examined, with a magnification change such that the outside diameter of the ring slit image is not varied.
Claim 3
Dependent Claim
38 words
An opthalmic photographing apparatus according to claim 1, wherein during narrow angle photography, as compared with during wide angle photography, the inside diameter of the ring slit image is made small without the outside diameter thereof being varied.
Claim 4
Dependent Claim
98 words
An opthalmic photographing apparatus having: photographing means for photographing the fundus of an eye to be examined at a variable magnification; a ring slit having an outside diameter and a baffle provided in an illuminating optical path for illuminating the fundus of the eye at positions substantially conjugate with front-eye-part and the crystalline lens, respectively; and means for varying the slit width of a ring slit image projected onto the eye to be examined and the size of a baffle image, with a magnification change such that the outside diameter of the ring slit image is not varied.
Claim 5
Dependent Claim
98 words
An opthalmic photographing apparatus having: photographing means for photographing the fundus of an eye to be examined at a variable magnification; a ring slit having an outside diameter and a baffle provided in an illuminating optical path for illuminating the fundus of the eye at positions substantially conjugate with front-eye-part and the crystalline lens, respectively; and means for varying the slit width of a ring slit image projected onto the eye to be examined and the size of a baffle image, with a magnification change such that the outside diameter of the ring slit image is not varied.
Claim 6
Dependent Claim
49 words
An opthalmic photographing apparatus according to claim 3, wherein during narrow angle photography, as compared with during wide angle photography, the inside diameter of the ring slit image is made small without the outside diameter thereof being varied and the outside diameter of the baffle image is made small.
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) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |