To provide an imaging optical system, imaging apparatus, and digital apparatus composed of four or more lenses, which makes it easier to adjust eccentricity.
The imaging optical system OSA according to the present invention comprises: four or more lenses, which are, in order from an object side to an image side, a first lens 1A of positive refractive power, a second lens 1B of negative refractive power; third and fourth lenses 3A and 4A of positive or negative refractive power; and, furthermore, a fifth lens 5A. The fifth lens 5A arranged on the side closest to an image of the four or more lenses has a non-spherical face having a perpendicular point in the direction of an effective area end from an intersection with the optical axis in the contour of a lens cross-section that includes an optical axis along the direction of the optical axis. The first lens 1A and a second lens 2A engage so that they move integrally, and further include lens barrel members 11A that hold the first lens 1A and the second lens 2A.
ONISHI SATOSHI
NISHIDA MAIKO
Masataka Otani
Satoshi Sakurai