Short distance zoom lens system
AssigneeNippon Kogaku K.K.
InventorSoichi Nakamura
Life of this patent
Estimating the term…
Abstract
A short distance zoom lens system for forming an image of an object lying at any short distance at a predetermined short distance comprises, in order from the object side, a first group which is a divergent lens group, a second group which is a convergent lens group, and a third group which is a divergent lens group. The second and the third group are movable relative to each other in the direction of the optic axis to effect a magnification change. The first group is stationary during the magnification change and is movable in the direction of the optic axis independently of the second and third groups in accordance with the distance to the object.
Claims6
A short distance zoom lens system for forming an image at a predetermined short distance from the lens system of an object lying at another short distance from the lens system, the zoom lens system consisting of, in order from the object side, a divergent first lens group, a convergent second lens group, and a divergent third lens group, said divergent first lens group comprising one positive lens component and two negative lens components, said convergent second lens group comprising one negative lens component and two positive lens components separated from said negative lens component, and said divergent third lens group comprising one negative lens component, and wherein said convergent second lens group and said divergent third lens group are movable relative to each other along the optical axis for effecting a magnification change, said divergent first lens group being stationary during the magnification change and being movable along the optical axis independently of said second and third groups in accordance with the distance to the object.
Dependencies are inferred from the claim text.