Abstract: A device for changing the position of an optical imaging system. In one preferred embodiment, a supporting ring surrounds the optical imaging system at least partially. At least one unit is provided which generates or is sensitive to a magnetic field. A casing element surrounds the supporting ring in a largely non-contacting manner, which provides a watertight enclosure of the supporting ring, inclusive of the optical imaging system. A controller surrounds the casing element, at least partially, and is provided with an equal number of units generating or sensitive to a magnetic field in a radial or axial direction relative to the unit in the supporting ring. The controller unit permits a non-contacting displacement of the supporting ring, inclusive of the optical imaging system, along the direction of its optical axis without any wear-inducing engaging operative mechanisms, by means of a magnetic force. In a second embodiment, the controller is a rod-shaped magnetic carrier.

Abstract: An endoscope has an objective arranged at its distal end, the image of which a relay-lens system conveys to the proximal end of the endoscope a light guide at least partially surrounds the relay-lens system and the objective, and conveys illumination light of an illumination light source from a light-entry connection to the distal end.The light guide is provided with a hollow-cylinder made of a transparent and optically clear material which surrounds the objective and the relay-lens system. The light from the illumination light source can be coupled into the circular front face of the hollow cylinder.