Optics: eye examining – vision testing and correcting – Eye examining or testing instrument – Objective type
Patent
1980-10-31
1984-02-07
Evans, F. L.
Optics: eye examining, vision testing and correcting
Eye examining or testing instrument
Objective type
A61B 310
Patent
active
044299605
ABSTRACT:
A keratometric device for attachment to a surgical microscope, the device including a housing member configured for receiving the bottom portion of the microscope therein, a screw elevator member rotatable relative to the housing member, having a screw thread about the exterior thereof and a second screw thread about the interior thereof. A ring gear is affixed to the elevator member with a knob and gear arrangement provided for rotating the elevator member. A ring lamp is provided with roller bearings engaging the external screw thread, the ring lamp providing a reference image. A prism support member is provided with outwardly extending roller bearing members for engaging the internal screw thread with a prism tray slidably movable relative to the prism support. A prism assembly is affixed to the prism tray for pivotal movement through a predetermined angle. The prism assembly includes a pair of disc-shaped prisms of different diameters mounted one atop the other for intercepting and deviating light passing through to the objective lens of the microscope for creating two virtual images in addition to the reference image. An electronic circuit provides a digital display indicative of the composite position of the ring lamp and prism support.
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patent: 4165744 (1979-08-01), Cravy
patent: 4315672 (1982-02-01), Muller
patent: 4375320 (1983-03-01), Smirmaul
Mesaros John G.
Mocilac Joseph P.
Terry Clifford M.
Evans F. L.
Mesaros John G.
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