| abstract |
To provide a high-definition imaging optical system that can sufficiently correct chromatic aberration while achieving sufficient compactness with a three-lens configuration. An imaging optical system includes, in order from the object side, a first lens having a positive optical power, a second lens having a positive optical power, and a third lens having a negative optical power. 13 is provided. In such an imaging optical system 10, a diffractive surface is formed on at least one of the lens surfaces 11a and 11b of the first lens 11 that is a positive lens and the lens surfaces 12a and 12b of the second lens 12. The When the power due to refraction of the lens including the diffractive surface is P L and the power due to refraction and diffraction of the entire imaging optical system 10 is P, the following conditional expression is satisfied. 0.2 <P L /P<2.0 [Selection] Figure 1 |