KERATOMETER Russian patent published in 2005 - IPC

FIELD: medical engineering.

SUBSTANCE: device has light source, adjustment mark being a ring, objective manufactured as bicomponent system having adjustment mark arranged in focal surface of the first objective component, conic mirror having mirror lining on external conic surface and opening in the center, conic mirror unit having mirror lining on internal conic surfaces. The common axis of all conic mirrors in the unit, the conic mirror and the opening is superposed over the optical axis of the objective. The unit is designed as a set of truncated cones having various tilt angles of conic surface generatrices with respect to the optical axis. The device also has unit for recording ring-shaped images of the adjustment mark. The tilt angles of conic surface generatrices are selected in a way that light beams reflect from conic mirror surfaces and each mirror surface of the conic mirrors unit, with the exception of the last one when counting from the objective, and light beams incident onto the cornea surface bypassing the conic mirrors having both external and internal mirror linings form optical cornea surface illumination channels at the exit from conic mirrors system. The channels intersect in the zone occupied by the cornea. Light beams incident onto the cornea in bypassing the conic mirrors and reflected from cornea surface after being sequentially reflected from the last conic mirror unit when counting from the objective, go in parallel to the optical axis until falling into the objective. They form single optical channel for recording ring-shaped images of the adjustment mark.

EFFECT: high reliability and accuracy in measuring geometrical size of external cornea surface; simplified design.

3 dwg