Image-forming lens, and imaging apparatus and information device using the image-forming lens

摘要

An image-forming lens includes, from an object side to an image side in order, a first lens group including a first F lens group with a negative refractive power and a first R lens group with a positive refractive power, an aperture, and a second lens group with a positive refractive power. The first F lens group includes, from the object side in order, a first negative lens which has a surface on the image side having a larger curvature and a second negative lens which has a surface on the object side having a larger curvature. A distance from a surface on a most object side of the first lens group to an image plane in a state of focusing on an object at infinity: L, and a maximum image height: Y′ satisfy Conditional expression 1: 2.8

主权项

1. An image-forming lens comprising, from an object side to an image side in order:
a first lens group; an aperture; and a second lens group with a positive refractive power, the first lens group including, from the object side in order: a first F lens group with a negative refractive power; and a first R lens group with a positive refractive power, the first F lens group including, from the object side in order: a first negative lens which has a surface on the image side having a large curvature; and a second negative lens which has a surface on the object side having a large curvature, and the first R lens group including: any one of a positive lens and a cemented lens with a positive refractive power as a whole, wherein a distance from a surface on a most object side of the first lens group to an image plane in a state of focusing on an object at infinity: L, a maximum image height: Y′, a curvature radius of the surface on the object side of the second negative lens: r21, and a curvature radius of a surface on the image side of the second negative lens: r22 satisfy Conditional expression 1: 2.8