Eye fundus camera

An eye fundus camera comprising:

• a lens system forming a main optical path to an eye fundus to be inspected and receiving light from the eye fundus;
• optical dividing means in the main optical path for forming first, second, and third auxiliary optical paths;
• plane forming means forming a recording plane in the first auxiliary path for holding a recording medium so that the lens system can form an image theron;
• display means having a sensing plane in said second auxiliary optical path for sensing the light from the eye fundus passing through said lens system and converting the image formed on said sensing plane into a visible image;
• mark defining means in the third auxiliary optical path for defining a mark with a given shape;
• projecting means in the third optical path for projecting the image of the mark onto the eye fundus with infrared light;
• light beam dividing means in the third auxiliary optical path for splitting the mark being projected onto the eye fundus into a plurality of different parts and for directing the parts along respectively different directions while the mark is projected on the eye fundus;
• said display means and said plane forming means forming a first arrangement and said lens system forming a second arrangement, said lens system and said optical dividing means forming an image of the eye fundus upon the recording plane and forming an image of the mark projected upon the eye fundus upon the sensing plane when the projecting means projects the image of the mark on the eye fundus;
• focusing means coupled to one of the arrangements for simultaneously adjusting the focus of the image of the eye fundus formed on the recording plane and the image of the mark on the eye fundus formed on the display means on the basis of the focus of the image of the mark on the eye fundus, and for separating the parts of the mark when the image of the eye fundus is out of focus and for causing the parts of the mark to assume the original shape of the mark when the image of the eye fundus is in focus.

An eye fundus camera comprising:

• an objective lens facing the eye to be inspected, and forming a main optical path,
• first optical path dividing means located on the main optical path on the side of the objective lens remote from the eye for dividing the optical path into the first and the second auxiliary optical paths,
• a first relay lens provided in said first auxiliary optical path,
• second optical path dividing means located on the first auxiliary path on the side of the relay lens more remote from the eye for dividing said first auxiliary optical path into the third and the fourth auxiliary optical paths,
• plane forming means in the third auxiliary optical path for defining a recording plane on which a recording medium is to be provided and on which the image of the eye fundus can be formed by said objective lens and said first relay lens,
• first focusing means coupled to said plane forming means for adjusting the focus of the image of the eye fundus formed on said recording means,
• mark defining means in the second auxiliary optical path for forming a mark with a predetermined shape,
• projecting means in the second auxiliary optical path for projecting the image of the mark on the eye fundus with infrared light along said second auxiliary optical path and through said objective lens, said projecting means including a second relay lens in the second optical path between said objective lens and the mark,
• second focusing means coupled to said projecting means for adjusting the focus of the image of the mark formed on the eye fundus, said first focusing means and the second focusing means being functionally engaged with each other for simultaneously focusing the image of the eye fundus formed on said recording medium and the image of the mark formed on the eye fundus,
• display means including a light sensing plane in fourth auxiliary optical path for sensing the infrared light coming from the eye fundus through said objective lens and said first relay lens and converting the infrared image formed on said light sensing plane into a visible image.

An eye fundus camera comprising:

• an objective lens facing the eye to be inspected and forming a main optical path;
• a first optical path dividing means in the main optical path on the side of the objective lens remote from the eye for dividing the main optical path and forming first and second auxiliary optical paths;
• a first relay lens in said first auxiliary optical path;
• second optical path dividing means in the first auxiliary optical path on the side of the first relay lens remote from the object to be inspected for dividing the first auxiliary optical path and forming third and fourth auxiliary optical paths;
• plane defining means in the third auxiliary optical path for forming a recording plane to receive an image of the eye fundus and being movable along the direction of the third auxiliary optical path;
• said objective lens and said relay lens being arranged to form an image of the eye fundus on said recording plane;
• first focusing means coupled to said plane defining means for adjusting the focus of the image of the eye fundus on said recording plane;
• mark forming means in said second auxiliary optical path for forming a mark having a predetermined shape;
• projecting means in said second auxiliary optical path for projecting the image of the mark on the eye fundus with infrared light along the second auxiliary optical path and through said objective lens;
• said projecting means including a lens for forming the image of the mark at a position in said second auxiliary optical path;
• said projecting means including a second relay lens optically equivalent to said first relay lens for projecting the image of said mark formed by said lens on the eye fundus;
• second focusing means coupled to said projecting means for moving the image of said mark formed in said second auxiliary optical path so as to adjust the focus of the image of the mark formed on the eye fundus, said first focusing means and said second focusing means being functionally connected with each other for simultaneously focusing the image of the eye fundus formed on said recording medium and the image of said mark formed on the eye fundus;
• display means in said fourth auxiliary optical path and having light sensing means along a plane for sensing infrared light coming from the eye fundus through the objective lens and said first relay lens and for converting the infrared image formed on the light sensing plane into a visible image.