Dual macro zoom optical system
Patent 4298251 Issued on November 3, 1981. Estimated Expiration Date: 
September 14, 1999. 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.
September 14, 1999. 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.Patent References 3773402 3784285 3884555 Large aperture extended range zoom lens Macro zoom lens Patent #: 4113355 InventorAssigneeApplicationNo. 06/075653 filed on 09/14/1979US Classes:359/693, With macro-type focusing359/705With macro type focusingExaminersPrimary: Clark, Conrad J.Attorney, Agent or FirmInternational ClassG02B 15/22 (20060101)AbstractThe system has a variator lens and a compensator lens which are mutually displaceable for varying the focal length of the optical system. In the normal zoom range, the focal length is adjustable between a telephoto condition and a wide angle condition, in accordance with the positions of the variator and compensator lenses. The system has macro capability in both a range beyond the extreme telephoto end of the zoom range and also in a range beyond the extreme wide angle end of the zoom range. In at least the macro range at the telephoto end, the slots in the camming sleeve for the variator and compensator lenses lie substantially in planes. | |
