20110007322 | METHOD AND ARRANGEMENT FOR DISPLACEMENT - A method and apparatus operable for displacing an image, which is transmitted by electromagnetic radiation, perpendicular to the direction of radiation by use of a rotatably disposed radiation-refracting body, located in the path of an imaging beam, having a refractive index that differs from the surrounding medium with regard to the radiation used. The method allows for precise image displacement. The rotation of the radiation-refracting body causing the displacement is measured, and the change of the optical path length caused by the angular change in a further electromagnetic beam utilized for the measurement is determined by evaluating the superimposition of the radiation reflected by a planar reflecting surface with the incident electromagnetic radiation. Part of the electromagnetic measurement beam, which is reflected on the surface of the radiation-refracting body, strikes a measurement unit, which supplies an electrical signal as a function of the incident position of the electromagnetic radiation. | 01-13-2011 |