A microscope is disclosed for observing a magnified area. Fade-in means arranged in the path of the rays of the microscope reflect a thin focused beam of light into the path of the rays. The beam of light is deflected or modulated by deflecting means to supply an image that can be recognized by an observer....http://www.google.co.uk/patents/US6304372?utm_source=gb-gplus-sharePatent US6304372 - Microscope including a fade-in element and related method of using a microscope
