| 摘要 |
An imaging optical system, an imaging device, and a digital apparatus of the invention are provided with an optical system constituted of five lens elements having positive, negative, positive, positive, and negative refractive powers, or positive, negative, negative, positive, and negative refractive powers; and satisfy the conditional expressions: 1<f123/f<1.25 0.1<d6/f<0.15 0.30<f4/f<0.72 where f: a focal length of the entirety of the imaging optical system, f123: a combined focal length of the first lens element 11, the second lens element 12, and the third lens element 13, d6: a distance on the optical axis between the third lens element 13 and the fourth lens element 14, and f4: a focal length of the fourth lens element 14. |
