| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical system and a mobile device that are capable of picking up a sharp image not only within a photographic range similar to those of a conventional silver salt camera and a digital camera, but also even when a subject is very nearer than in a conventional imaging range. SOLUTION: An imaging optical system which forms an image on an imaging element comprises two lenses and a stop, and is moved as one body along the optical axis to satisfy a condition represented by (a) 10<F<SP>2</SP>/√¾β¾<200, where F is the F number of the imaging optical system at an infinite distance andβis the power of the imaging optical system and also the power when the imaging optical system is at the farthest distance from the imaging element. The mobile device uses the imaging optical system. COPYRIGHT: (C)2004,JPO |
