Ophthalmoscopic optical system

Claim 2

An ophthalmoscopic optical system comprising: (a) a front optical member facing an eye with a fundus to be examined and having an optical axis; (b) an image forming lens positioned on the image side of said front optical member in axial alignment therewith; (c) an illuminating arrangement including at least one light source, a lens group and an apertured member and having an optical axis; (d) a reflecting member having a reflecting plane surrounded by an annular zone, said reflecting plane coinciding with a point at which the optical axis of said front optical member and that of said illuminating arrangement intersect each other, said reflecting plane being positioned to reflect toward the eye light emitted by said light source and passing through said apertured member; of said illuminating arrangement and (e) said annular zone including a transparent aperture, said transparent aperture being disposed between said front optical member and said image forming lens for passing image-forming rays.

Claim 3

An ophthalmoscopic optical system comprising: (a) a front optical member facing an eye with a fundus to be examined and having an optical axis; (b) an image forming lens positioned on the image side of said front optical member in axial alignment therewith; (c) an illuminating arrangement including at least one light source, a lens group and an apertured member and having an optical axis; (d) a reflecting member having a reflecting plane surrounded by an annular zone, said reflecting plane coinciding with a point at which the optical axis of said front optical member and that of said illuminating arrangement intersect each other, said reflecting plane being positioned to reflect toward the eye light emitted by said light source and passing through said apertured member of said illuminating arrangement; and (e) said annular zone including a transparent aperture, said transparent aperture being disposed between said front optical member and said image forming lens for passing image-forming rays. and wherein said reflecting member has a central mirrored portion surrounded by said annular zone.

Claim 4

An ophthalmoscopic optical system comprising: (a) a front optical member facing an eye with a fundus to be examined and having an optical axis; (b) an image forming lens positioned on the image side of said front optical member in axial alignment therewith; (c) an illuminating arrangement including at least one light source, a lens group and an apertured member and having an optical axis; (d) a reflecting member having a reflecting plane surrounded by an annular zone, said reflecting plane coinciding with a point at which the optical axis of said front optical member and that of said illuminating arrangement intersect each other, said reflecting plane being positioned to reflect toward the eye light emitted by said light source and passing through said apertured member of said illuminating arrangement; and (e) said annular zone including a transparent aperture, said transparent aperture being disposed between said front optical member and said image forming lens for passing image-forming rays. and wherein said reflecting member has a central mirrored portion surrounded by said annular zone.

Claim 5

An ophthalmoscopic optical system as claimed in claim 1, further including at least one small light-shielding region on the optical axis at a location between said image forming lens and an image plane.

Claim 6

An ophthalmoscopic optical system as claimed in claim 3, wherein said small light-shielding region is a transparent plate with a black disc.

Claim 7

An ophthalmoscopic optical system comprising: (a) a front optical member facing an eye with a fundus to be examined and having an optical axis; (b) an image forming lens positioned on the image side of said front optical member in axial alignment therewith; (c) an illuminating arrangement including at least one light source, a lens group and an apertured member and having an optical axis; (d) a reflecting member having a reflecting plane surrounded by an annular zone, said reflecting plane coinciding with a point at which the optical axis of said front optical member and that of said illuminating arrangement intersect each other, said reflecting plane being positioned to reflect toward the eye light emitted by said light source and passing through said apertured member of said illuminating arrangement; and (e) said annular zone including a transparent aperture, said transparent aperture being disposed between said front optical member and said image forming lens for passing image-forming rays; wherein said front optical member is an objective lens, said image forming lens is a photographic relay lens situated rearwardly therefrom in axial alignment therewith, said reflecting member is a reflecting plate having a central mirrored portion and said annular zone being disposed around said central mirrored portion and disposed between said objective lens and said photographic relay lens inclined at an angle to the optical axis, and said illuminating arrangement including light sources for illumination and photography of which images are formed at a common conjugate point to said central mirrored portion of said reflection plate with respect to a relay lens.

Claim 8

An ophthalmoscopic optical system comprising: (a) a front optical member facing an eye with a fundus to be examined and having an optical axis; (b) an image forming lens positioned on the image side of said front optical member in axial alignment therewith; (c) an illuminating arrangement including at least one light source, a lens group and an apertured member and having an optical axis; (d) a reflecting member having a reflecting plane surrounded by an annular zone, said reflecting plane coinciding with a point at which the optical axis of said front optical member and that of said illuminating arrangement intersect each other, said reflecting plane being positioned to reflect toward the eye light emitted by said light source and passing through said apertured member of said illuminating arrangement; and (e) said annular zone including a transparent aperture, said transparent aperture being disposed between said front optical member and said image forming lens for passing image-forming rays; wherein said front optical member is an objective lens, said image forming lens is a photographic relay lens situated rearwardly therefrom in axial alignment therewith, said reflecting member is a reflecting plate having a central mirrored portion and said annular zone being disposed around said central mirrored portion and disposed between said objective lens and said photographic relay lens inclined at an angle to the optical axis, and said illuminating arrangement including light sources for illumination and photography of which images are formed at a common conjugate point to said central mirrored portion of said reflection plate with respect to a relay lens.

Claim 9

An ophthalmoscopic optical system as claimed in claim 5, wherein the image of said light source is formed on said apertured member by a condensor lens.

Claim 10

An ophthalmoscopic optical system as claimed in claim 5, further including at least one transparent plate positioned behind said photographic relay lens and provided with a black dot located at a point at which said transparent plate intersects the optical axis.

Claim 11

An ophthalmoscopic optical systemas claimed in claim 5, wherein said objective lens is of bi-convex configuration having front and rear-curved surfaces having radii of curvature for which: α/h.sub.1 = β/h.sub.2 wherein α is the angle of emergence with respect to the optical axis of an illuminating ray after entering said objective lens through the rear surface (R 2 ) thereof followed by reflection from the front surface (R 1 ) thereof to the rear surface (R 2 ); h 1 is the height of emergence; β is the angle of incidence with respect to the optical axis of an illuminating ray impinging on the rear surface (R 2 ) of said objective lens from the image side followed by reflection therefrom; and h 2 is the height of incidence.