Imaging apparatus having a curved image surface

摘要

Provided is an imaging apparatus, including: an imaging optical system including a plurality of lenses; and an image plane which is disposed on an image side of the imaging optical system and is curved so that a concave surface thereof faces an object side of the imaging optical system. The imaging optical system includes an aperture stop. In the imaging optical system, a lens closer to the object side than the aperture stop and a lens closer to the image side than the aperture stop have different positive powers. A focal length of the imaging optical system is substantially equal to a distance from an exit pupil of the imaging optical system to the image plane. A radius of curvature of the image plane is substantially equal to the focal length of the imaging optical system.

主权项

1. An imaging apparatus comprising:
an imaging optical system including (a) an aperture stop, (b) a first optical system disposed on an object side of the aperture stop, and (c) a second optical system disposed on an image side of the aperture stop; and a light-receiving surface which is disposed on an image side of the imaging optical system and is a concave surface facing the imaging optical system, wherein the first optical system and the second optical system have different positive power, wherein the first optical system includes a first lens closest to the object side and a second lens adjacent to the first lens, wherein the second optical system includes a third lens closest to the image side and a fourth lens adjacent to the third lens, wherein a difference between an Abbe number of the third lens and an Abbe number of the fourth lens is larger than a difference between an Abbe number of the first lens and an Abbe number of the second lens, and wherein the following conditional expressions are satisfied:
0.8≦|Rimg|/fsys≦1.5, and0.8≦|Rimg|/dpup≦1.5where fsys represents a focal length of the imaging optical system, dpup represents a distance from an exit pupil of the imaging optical system to the light-receiving surface, and Rimg represents a radius of curvature of the light-receiving surface.