Compact refractor for subjective examination of human eyes

US5812241A · kind A · utility

Assignee

• Block Medizintechnik GmbH · DE

Inventors

• Manfred Doms · Saalfeld, DE
• Ulrich Fischer · Ditzingen, DE

Key dates

• Filing date: Feb 16, 1996
• Grant date: Sep 22, 1998
• Expiry date: Feb 16, 2016

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B3/04
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A compact and precise phoropter of low requirements as to material and favorable as to kinematics comprises two observation channels in each of which a plurality of equal sized disks are rotatably and coaxially arranged about an axle, each of said disks being provided with a number of element sites where spherical lenses, cylindrical lenses, cross cylinders and further optically effective accessory elements are located. At least the cylindrical lenses are seated for rotation on said disks and are provided with first drive wheels, the diameters of the latter being substantially equal to the diameter of a second drive wheel rotatable with the axle and being associated to the respective disk. The diameters of the entire disks are determined by the diameters of the first and the second drive wheels and are at least three-fold the diameter of the first drive wheels.