Photographic lens
AssigneeFuji Photo Optical Co., Ltd.
InventorYoshikazu Shinohara
Life of this patent
Estimating the term…
Abstract
A compact photographic lens for a digital camera is disclosed. The photographic lens has only two lens elements, yet provides excellent imaging even at the periphery of the image field. The photographic lens of the invention and an image sensor, together, fit within a volume of about 10 cm3. The lens is formed of, in order from the object side, a biconvex lens element having two aspherical surfaces, and a positive meniscus lens element having two aspherical surfaces. The convex surface of the meniscus lens element is positioned on the image side, and various conditions are satisfied in order to provide the photographic lens with a short overall length while favorably correcting various aberrations.
Claims4
A photographic lens having only two lens elements, said photographic lens comprising, in order from the object side:
- a biconvex lens element having two aspherical surfaces;
- and
- a positive meniscus lens element having two aspherical surfaces and with its convex surface on the image side;
- wherein the following Conditions (1) and (2) are satisfied:
- 2*dd2<dd1 Condition (1)
- |R3|<|R4| Condition (2)
- where,
- dd1 is the on-axis distance between the object-side surface and the image-side surface of the biconvex lens element,
- dd2 is the on-axis distance between the image-side surface of the biconvex lens element and the object-side surface of the positive meniscus lens element,
- |R3| is the absolute value of the radius of curvature of the image-side surface of the biconvex lens element, and
- |R4| is the absolute value of the radius of curvature of the object-side surface of the meniscus lens element.
Dependencies are inferred from the claim text.