A small size and lightweight light beam scanning device for scanning a laser beam to perform an operation under an operating microscope. A movable mirror is provided which occupies only a small central portion of the objective lens of the microscope. Horizontal rotary shafts are provided on an annular...http://www.google.fr/patents/US4406525?utm_source=gb-gplus-shareBrevet US4406525 - Light beam scanning device
