US3914032A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for observing and photographing the fundus of eye
Assignee: Canon Inc
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Filing: 1973-09-14
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Granted: 1975-10-21
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Expires: 1993-09-14
Abstract
Abstract A device for observing and photographing the fundus of eye including an optical system for directly observing or photographing the fundus of the eye of a person to be inspected and an optical system for projecting the illuminating light bundle to the fundus of the eye. Both optical systems utilize one and the same objective lens commonly used therein, wherein means is provided in said objective lens for reducing the incident angle to each of the refracting surfaces of said objective lens by increasing the number of such refracting surfaces, for improving compensation for the aberrations by applying an aspherical surface to one of said refracting surfaces and for removing the reflecting light by the cornea of the eye to be inspected on the surface of a single lens constituting said objective lens, means for regulating the position, of said objective lens with respect to the eye to be inspected by said objective lens being adapted to cooperate with said first mentioned means for permitting a broad and sharp image to be obtained.
Inventors
- 👤 Eiichi Takano
- 👤 Kunio Takesi
- 👤 Isao Matsumura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:58
CPC Classifications
A; A61; A61B; A61B3/00; A61B3/10; A61B3/14
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
238 words
A device for observing and photographing the retina of a human eye comprising: positioning means for fixedly establishing the position of the eye to be examined, a fundus inspection optical system comprising an objective lens having an optical axis, a reflecting means obliquely provided on said optical axis of said objective lens and an observing optical system for observing and photographing the retina of the eye being examined, said observing optical system being provided on said optical axis of said objective lens, and an illuminating optical system having an optical axis crossing with said optical axis of said objective lens and comprising a light source and a projection lens group, wherein the light from said illuminating optical system is reflected at said reflecting means to the eye through said objective lens, said objective lens comprising a front lens group and a rear lens group said front lens group being closer to the eye and said rear lens group being closer to said observing optical system, the surface of the front lens group having the greatest power being convex towards said observation side and the surface of the rear lens group having the greatest power being convex towards the eye being examined, and means for supporting the fundus inspection optical system and for adjusting the position thereof, both of said lens groups being positioned along the axis closer to the position at which the positioning means places the eye.
Claim 2
Independent Claim
238 words
A device for observing and photographing the retina of a human eye comprising: positioning means for fixedly establishing the position of the eye to be examined, a fundus inspection optical system comprising an objective lens having an optical axis, a reflecting means obliquely provided on said optical axis of said objective lens and an observing optical system for observing and photographing the retina of the eye being examined, said observing optical system being provided on said optical axis of said objective lens, and an illuminating optical system having an optical axis crossing with said optical axis of said objective lens and comprising a light source and a projection lens group, wherein the light from said illuminating optical system is reflected at said reflecting means to the eye through said objective lens, said objective lens comprising a front lens group and a rear lens group said front lens group being closer to the eye and said rear lens group being closer to said observing optical system, the surface of the front lens group having the greatest power being convex towards said observation side and the surface of the rear lens group having the greatest power being convex towards the eye being examined, and means for supporting the fundus inspection optical system and for adjusting the position thereof, both of said lens groups being positioned along the axis closer to the position at which the positioning means places the eye.
Claim 3
Dependent Claim
118 words
A device for observing and photographing the retina of the human eye according to claim 1, wherein the front lens group forms a concave front surface facing said eye and a convex rear surface facing the observing optical system, the rear lens group having rear convex surface facing said observing optical system,, said reflecting means having one perforation at a portion where it crosses the optical axis of said fundus inspection optical system, the center of curvature of said front surface of said front lens group matching the center of the pupil of said eye, the center of curvature of said rear plane of said rear lens group matching the center of said perforation of said reflecting means.
Claim 4
Dependent Claim
48 words
A device for observing and photographing the retina of a human eye according to claim 2, further comprising a light shielding means for eliminating undesired light and being provided at the portion where said optical axis of said fundus inspection optical system crosses one of said rear surfaces.
Claim 5
Dependent Claim
33 words
A device for observing and photographing the fundus of the eye according to claim 1, wherein said objective lens includes refracting surfaces and a surface of the refracting surfaces comprises an aspherical surface.
Claim 6
Dependent Claim
44 words
A device for observing and photographing the fundus of the eye according to claim 4, wherein the radius of curvature of said refracting surfaces of said objective lens are equal to no more than 80% of the resultant focal length of said objective lens.
Claim 7
Dependent Claim
24 words
A device as in claim 3, wherein said light shielding means includes a mask located at the rear surface of said front lens group.
Claim 8
Dependent Claim
24 words
A device as in claim 3, wherein said light shielding means includes a mask located at the rear surface of saiD rear lens group.
Claim 9
Dependent Claim
22 words
A device as in claim 3, wherein said light shielding means are located to shield light at each of said rear surfaces.
Claim 10
Independent Claim
146 words
A device for observing the retina of a human eye, comprising an objective lens forming a path of light, an observing lens in the path of light from the objective lens, illuminating means for projecting light across the path of light, reflecting means between the objective lens and the observing lens located to direct light from the illuminating means toward the objective lens, said reflecting means being formed and located to permit at least a portion of the light from the objective lens to bypass the reflecting means, said objective lens comprising a front lens group directed outwardly from the objective lens and a rear lens group positioned closer to the observing lens, said front lens group having a front surface with a center of curvature located beyond the end of the objective lens away from the observing lens, said objective lens having a non-spherical surface.
Claim 11
Independent Claim
146 words
A device for observing the retina of a human eye, comprising an objective lens forming a path of light, an observing lens in the path of light from the objective lens, illuminating means for projecting light across the path of light, reflecting means between the objective lens and the observing lens located to direct light from the illuminating means toward the objective lens, said reflecting means being formed and located to permit at least a portion of the light from the objective lens to bypass the reflecting means, said objective lens comprising a front lens group directed outwardly from the objective lens and a rear lens group positioned closer to the observing lens, said front lens group having a front surface with a center of curvature located beyond the end of the objective lens away from the observing lens, said objective lens having a non-spherical surface.
Claim 12
Dependent Claim
57 words
An apparatus as in claim 9, wherein the surface of the front lens group having the greatest power is convex toward the observing lens and the surface of the rear lens group having the greatest power is convex toward the eye being examined, and wherein means support the lenses and illuminating means for adjusting the position thereof.
Claim 13
Dependent Claim
54 words
An apparatus as in claim 9, wherein the means for allowing the reflecting means to bypass a portion of light from the objective lens includes a perforation in the reflecting means, said rear lens group having a rear plane with a center of curvature matching the center of the perforation of said reflecting means.
Claim 14
Dependent Claim
43 words
An apparatus as in claim 11, wherein said objective lens includes a rear surface and a plurality of surfaces between the front surface and the rear surface, said aspherical surface being one of the plurality of surfaces between the front and rear surface.
Claim 15
Dependent Claim
77 words
An apparatus as in claim 9, wherein support means support the objective lens and the observing lens as well as the reflecting means and the illuminating system, said support means providing means for supporting the face having the human eye to be observed, said supporting means supporting the objective lens so that the center of curvature of said front surface of said front lens group can match the center of the pupil of the eye being observed.
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) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |