Zoom lens system and image pickup apparatus with the system
AssigneeCanon Kabushiki Kaisha
InventorHiroshi Saruwatari
Life of this patent
Estimating the term…
Abstract
At least one exemplary embodiment is directed to a zoom lens system, which can have a diffractive optical element, achieves high optical performance over a wide zoom range. The zoom lens system includes a first lens unit having positive optical power, a second lens unit having negative optical power, and a rear lens component including at least one lens unit having positive optical power. The first lens unit, the second lens unit, and the rear lens component are arranged in that order from an object side towards an image side of the zoom lens system. The diffractive optical element is included in the first lens unit. The rear lens component is provided with a positive lens element having extraordinary dispersion characteristics.
Claims10
A zoom lens system comprising:
- a first lens unit having positive optical power and including a diffractive optical portion;
- a second lens unit having negative optical power and movable along an optical axis for a zooming operation;
- and
- a rear lens component including at least one lens unit having positive optical power,
- wherein the first lens unit, the second lens unit, and the rear lens component are arranged in that order from an object side towards an image side of the zoom lens system, and
- wherein the rear lens component includes a positive lens element that satisfies the conditional formula νp·θgF>38, νp representing an Abbe number of a material of the positive lens element, θgF representing a partial dispersion ratio of a material of the positive lens element.
Dependencies are inferred from the claim text.