Patent ID: 7649684

Claim:
An optical apparatus comprising: an observation apparatus having an objective, an observation optical system unit that includes a variable magnification optical system, and an imaging optical system unit including an imaging lens and an eyepiece; and a fluorescence illumination apparatus comprising: a light source; first and second reflecting members configured to guide illuminating light from between said variable magnification optical system and said objective to an optical path toward a distal end of said objective; an illumination optical system, placed between said light source and said first reflecting member to lead illuminating light from said light source to said first reflecting member; a frame having at least one socket; and at least one post configured to be inserted into the at least one socket, wherein illuminating light from the fluorescence illumination apparatus passes through the objective only without passing through the variable magnification optical system; and wherein a first wavelength selecting member for selectively transmitting light in a specific wavelength region in said illuminating light is placed between said light source and said second reflecting member, and a second wavelength selecting member for selectively transmitting light in a wavelength region of fluorescent light emitted from a sample is placed between said variable magnification optical system and said imaging optical system unit; wherein said fluorescence illumination apparatus includes an illumination zooming system provided separately from the variable magnification system of the observation optical system, wherein the optical apparatus is configured to operate in two modes: (i) a fluorescent observation mode, wherein the fluorescence illumination apparatus is removably mounted to the observation apparatus; and (ii) a non-fluorescent observation mode, wherein the fluorescence illumination apparatus is removed from the optical apparatus, wherein the at least one socket comprises two sockets, one socket being closer to a sample, and the at least one post comprises one post, and wherein (i) in the fluorescent observation mode, the post is inserted into the socket further away from the sample; and (ii) in the non-fluorescent observation mode, the post is inserted into the socket closer to the sample.