Patent ID: 7440184

Claim:
In a microscope having an objective lens to be used commonly for a dark field observation, bright field observation and a fluorescence observation, the improvement comprising in combination: an illumination optical element changer that is capable of selectively inserting any of a bright field illumination optical element, a dark field illumination optical element and a fluorescence illumination optical element into a optical axis of the objective lens; a field stop that is disposed on the optical axis and limits a visual field of the objective lens; an aperture stop that is disposed on the optical axis and limits a pupil area of the objective lens; a filter member that is disposed on the optical axis and limits a given ultraviolet wavelength range or adjusts a light quantity of illumination light of an illumination light source; a rotation shaft that rotates in response to the changing movement of the illumination optical element changer; and an interlocking means that brings the aperture stop, the field stop and the filter member into respective setting conditions corresponding to the selected illumination optical element in response to the rotation of the rotation shaft.