Snider & Associates
Imaging lens
 An imaging lens comprises a front group constituted by a first lens L.sub.1 made of a negative meniscus lens having a convex surface directed onto the object side, the object-side surface thereof being made aspheric, and a second lens L.sub.2 made of a biconvex lens having a surface with a larger curvature directed onto the object side; and a rear group constituted by a third lens L.sub.3 made of a biconcave lens and two biconvex lenses L.sub.4, L.sub.5. Letting d be the distance from the object-side surface of the first lens L.sub.1 to the image-side surface of the second lens L.sub.2, f be the focal length of the whole lens system, and n.sub.A and .nu..sub.A be average values of refractive index and Abbe number, respectively, in the two biconvex lenses L.sub.4, L.sub.5, the imaging lens satisfies 1.0<d/f<2.0, n.sub.A >1.76, and .nu..sub.A >45.0. Thus, while maintaining a compact configuration constituted by five lenses, the imaging lens allows various kinds of aberration such as chromatic aberration in magnification to become favorable even when applied to a CCD imaging device having a large number of pixels. 
Fuji Photo Optical Co., Ltd.
G G
G02B G02B
inventional inventional
Hiroshi
Yamada