Afocal zoom lens for microscopes
AssigneeOlympus Corporation
InventorKenji Kawasaki
Life of this patent
Estimating the term…
Abstract
An afocal zoom lens for microscopes includes five lens units having, in order from the object side, positive, negative, negative, positive, and negative refracting powers. When the magnification of the afocal zoom lens is changed in the range from a low-magnification position to a high-magnification position, a first lens unit and a fifth lens unit are fixed, a second lens unit is moved toward the image side, and a fourth lens unit is moved toward the object side. The afocal zoom lens satisfies the following condition: 0≦F2/F3≦2.5 where the focal length of the second lens unit is represented by F2 and the focal length of a third lens unit is represented by F3. The third lens unit is constructed with at least one negative lens with a concave surface facing the object side.
Claims9
An afocal zoom lens for microscopes, comprising five lens units having, in order from an object side, positive, negative, negative, positive, and negative refracting powers, wherein when a magnification of the afocal zoom lens is changed in a range from a low-magnification position to a high-magnification position, a first lens unit and a fifth lens unit are fixed, a second lens unit is moved toward the image side, and a fourth lens unit is moved toward the object side.
Dependencies are inferred from the claim text.