Imaging lens

摘要

An imaging lens which can be very compact and thin, corrects various aberrations properly and provides a small F-value and a wide view angle at low cost. In the imaging lens, designed for a solid-state image sensor, arranged in the following order from an object side to an image side are: a first positive (refractive power) lens with a convex object-side surface; a second positive lens; a third positive lens; a fourth positive lens; and a fifth negative lens with a concave image-side surface. None of these lenses is joined to each other and all the lens surfaces are aspheric. The object-side and image-side aspheric surfaces of the fifth lens have a pole-change point in a position other than a point of intersection with an optical axis. A diffractive optical surface is formed on one of three surfaces from the first lens image-side surface to the second lens image-side surface.

主权项

1. An imaging lens for a solid-state image sensor in which lenses are arranged in order from an object side to an image side, comprising:
a first lens with positive refractive power having a convex surface on the object side; a second lens with positive refractive power; a third lens with positive refractive power; a fourth lens with positive refractive power; and a fifth lens with negative refractive power having a concave surface on the image side, wherein none of the constituent lenses is joined to each other; wherein all the lens surfaces are aspheric; wherein an object-side aspheric surface and an image-side aspheric surface of the fifth lens have a pole-change point in a position other than a point of intersection with an optical axis; and wherein a diffractive optical surface is formed on one of three surfaces from the image-side surface of the first lens to the image-side surface of the second lens.