Optical element change-over control apparatus and microscope using the same

A microscopic apparatus using an optical element change-over control apparatus, the optical element change-over control apparatus comprising:

• an optical element change-over member capable of holding a plurality of optical elements and rotating alternatively to locate a specific optical element on an optical path;
• a driving element for rotating the optical element change-over member;
• a positioning detecting element for detecting the selected optical element being positioned so that the optical element stays in a predetermined position on the optical path and outputting positioning signals;
• an origin detecting element for detecting the point of origin of the optical element change-over member;
• and
• a control element for driving the driving element to rotate the optical element change-over member and counting the positioning signals delivered from the positioning detecting element during the time interval that elapses from the instant that the point of origin of the optical element change-over member is first detected by means of the origin detecting element until the point of origin of the optical element change-over member is secondly detected by means of the origin detecting element, thereby detecting the number of change-over stages of the optical element change-over member.

A method for detecting the number of change-over stages of an optical element change-over member capable of holding a plurality of optical elements and rotating alternatively to locate a specific optical element on an optical path, the method comprising:

• a member rotating step of driving a driving element to rotate the optical element change-over member;
• a first origin position detecting step of detecting the origin position of the optical element change-over member by means of an origin detecting element;
• a positioning signal detecting step of determining whether or not a positioning signal, indicative of the selected optical element being positioned so that the optical element stays in a predetermined position on the optical path, is detected after the origin position is detected and incrementing a count value indicative of the number of change-over stages of the optical element change-over member by one every time the positioning signal is detected;
• and
• a second origin position detecting step of determining whether or not the origin position of the optical element change-over member is detected again during the execution of the positioning signal detecting step and stopping the rotation of the optical element change-over member when the origin position is detected.