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US 8,508,862 B2Granted
Image pickup lens and image pickup apparatus
AssigneeFUJIFILM Corporation
InventorYu Kitahara
Life of this patent
Estimating the term…
Abstract
An image pickup lens having a four lens configuration in which a bi-concave first lens, a bi-convex second lens, a bi-concave third lens, and a positive fourth lens are disposed in this order from an object side. Here, at least one of the first, second, third, and fourth lenses has an aspherical surface on each side. The image pickup lens satisfies Conditional Expression (1) given below when a refractive index of the second lens with respect to d-line is taken as Nd2. 1.6<Nd2 (1)
Claims11
An image pickup lens, comprising:
- a four lens configuration in which a bi-concave first lens, a bi-convex second lens, a bi-concave third lens, and a positive fourth lens are disposed in this order from an object side,
- wherein:
- at least one of the first, second, third, and fourth lenses has an aspherical surface on each side,
- the image pickup lens satisfies Conditional Expression (1) given below when a refractive index of the second lens with respect to d-line is taken as Nd2:
- 1.6<Nd2 (1), and
- the image pickup lens satisfies Conditional Expression (5) given below when a focal length of the entire lens system is taken as f and a distance between the first and second lenses on an optical axis is taken as D12:
- 0.5<D12/f <1.5 (5).
4 more elements
Dependencies are inferred from the claim text.