Imaging lens including a lens with convex surfaces facing each of an object and an image side

摘要

A compact low-cost imaging lens which provides high brightness with an F-value of 2.5 or less and a wide field of view and corrects aberrations properly, meeting the demand for low-profile design. The imaging lens elements are arranged in the following order from an object side to an image side: an aperture stop; a first lens with positive refractive power having a convex surface on each of the object and image sides; a second lens with negative refractive power; a third lens with positive refractive power having a convex surface on each of the object and image sides; a fourth lens with negative refractive power; and a fifth lens with negative refractive power as a double-sided aspheric lens. The imaging lens satisfies a conditional expression (1) below:
1.5

主权项

1. An imaging lens which forms an image of an object on a solid-state image sensor comprising, in order from an object side to an image side of the imaging lens:
an aperture stop; a first lens having positive refractive power and convex surfaces facing each of the object side and the image side; a second lens having negative refractive power; a third lens having positive refractive power and convex surfaces facing each of the object side and the image side; a fourth lens having negative refractive power; and a fifth lens having negative refractive power that is a double-sided aspheric lens, wherein conditional expressions (1) and (2) below are satisfied:
1.5f: focal length of an overall optical system of the imaging lensf3: focal length of the third lensf4: focal length of the fourth lens.