IMAGING OPTICAL SYSTEM, AND IMAGING APPARATUS WITH THE SAME

Japanese Patent JP2022052311

A

To provide an imaging optical system in which an optical system has a short overall length and has a wide depth of field.SOLUTION: An imaging optical system comprises, in order from the object side, a first lens group having negative refractive power, a second lens group and a third lens group each having positive refractive power, the second lens group has a diaphragm and an optical surface performing phase modulation. The optical surface is arranged at a position that matches the diaphragm or in the vicinity of the diaphragm, change occurs in the phase of wavefront by phase modulation, and the size of a permissible circle of confusion when the change occurs is larger than the size of a permissible circle of confusion when the change does not occur. The imaging optical system satisfies conditional expression (1): D2×cosα