Patent 4781457 Issued on November 1, 1988. Estimated Expiration Date: November 1, 2005. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
A laser surveying equipment includes a laser beam luminous section, a suspending reflection member suspended in such a manner as to reflect laser beam radiated from the laser beam luminous section upward and always to direct the optical axis of such reflected light in the perpendicular direction, and a projection lens system adapted to project the laser beam after forming it into a generally parallel flux of light. A rotary reflection member can be rotatably arranged in order to displace by approximately 90 degree an optical path of parallel flux of light obtained from the projection lens system and to scan the parallel flux of light toward a surveying object within a horizontal plane.