Patent ID: 7380943
Filing Date: 2008-06-03
Classification: A61B

Abstract:
1. A method for determining the adjusted magnification step in ophthalmologic instruments, particularly slit lamps, comprising: reading off magnification steps at the rotational axis of a magnification changer, monitoring said steps by a control unit; and storing the magnification setting for reproduction, and wherein the magnification steps are read off by Hall sensors at a cylinder arranged on the rotational axis of the magnification changer, which cylinder has for this purpose on or in its jacket surface magnets with radially oriented magnetic fields which divide the cylinder into segments, at least two magnets being provided at the segment boundaries in a defined geometric arrangement and oriented in such a way that the pole arrangement of the associated magnets located at a segment boundary occurs only once in this combination and arrangement on or in the jacket surface of the cylinder, and wherein an identical quantity of sensors is located opposite from these magnet arrangements in the same geometric arrangement for reading off the magnification steps, and the read off magnification steps are monitored and stored by a control unit.