Patent ID: 8675285

Claim:
A changer comprising: an axis of rotation for at least one optical element for at least one optical path comprising an optical axis, wherein the changer inserts the at least one optical element into the at least one optical path by means of a rotary motion or removes it from this optical path, wherein the at least one optical path is one of at least two spatially connected optical paths and that the axis of rotation of the changer is located between two parallel lines, wherein the parallel lines run in the plane through the interfaces of the optical axes of the optical paths with one plane, which intersects the optical axes under the same angles and is thereby perpendicular to the plane, which is spanned by the optical axes, wherein the parallel lines are perpendicular to the connecting line between the two interfaces of the optical axes of the optical paths with the one plane, which intersects the optical axes under the same angles, wherein the at least one optical element is a lens, a mirror, a filter, a DOE, an optical grating, a beam splitter or a diaphragm, wherein the filter is suitable for fluorescence excitation or for fluorescence detection, wherein the angle between the optical axis and this one plane which is intersected by the optical axis is substantially 90° or 45°, wherein the at least one optical path is one of at least two spatially connected optical paths and the at least one optical element, if rotated by 360° around the changer's axis of rotation, would cross also the second of the at least two spatially connected optical paths, wherein the at least two spatially connected optical paths are two different parts of the same optical path, wherein these parts are separated by a beam splitter or a mirror, wherein the axis of rotation and the optical axis of the beam path are at an angle and the distance of the optical elements, which are outside the optical beam path, is smaller than the diameter of the beam path, preferably smaller than 75% of the diameter of the beam path, further preferably smaller than 50% of the diameter of the beam path, wherein the angle between its axis of rotation and the optical axis of the beam path is substantially 45°, and wherein the optical elements are lenses, the changer has two sets of the lenses arranged in the beam path in a consecutive way, which satisfy the condition |fi+fj|=dij, wherein d is the distance of the lenses inserted into the beam path, f is the focal length of the lens, i is the index for the first set of lenses, and j is the index for the second set of lenses.