Patent ID: 11930256
Assignee: FUJIFILM CORPORATION
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 21:
22. An imaging optical system comprising:
a first pupil region for passing light in a first wavelength range; and
a second pupil region for passing light in a second wavelength range different from the first wavelength range,
wherein an axial chromatic aberration of the imaging optical system due to a difference between the first wavelength range and the second wavelength range is reduced based on a relationship between an aberration other than the axial chromatic aberration of the imaging optical system and positions of the first pupil region and the second pupil region in the imaging optical system,
in a case where n represents an integer of 2 or more, i represents a parameter which changes in a range of 1 to n, Ωi represents an i-th pupil region in the imaging optical system, λij represents a representative wavelength of light transmitted the i-th pupil region Ωi, mi represents the number of representative wavelengths in the i-th pupil region Ωi, j represents a parameter which changes in a range of 1 to m, λij represents a j-th representative wavelength in the i-th pupil region Ωi, f(λ) represents a paraxial focal length of the imaging optical system at a wavelength λ, g(x,y;λ) represents an on-axis longitudinal aberration of the wavelength λ in a pupil coordinate (x,y) of the pupil region in the imaging optical system, and SΩi represents an area of the i-th pupil region Ωi, the imaging optical system has a combination of i1, i2, j1, and j2 satisfying the following [expression 1] and [expression 2] (where, a≥b),, ❘
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the imaging optical system has a front lens group disposed on an object side with respect to a stop, and a rear lens group disposed on an image side with respect to the stop,
the first pupil region and the second pupil region are located between the front lens group and the rear lens group, and
the front lens group has an angular magnification which makes an angle of off-axis principal ray incident on the first pupil region and the second pupil region close to perpendicular to a stop plane.