| 摘要 |
A compact optical system for a digital photographing device is provided to improve a production yield by lowering the sensitivity while sequentially including a diaphragm, a positive refracting power, a negative refracting power, and the positive refracting power in the optical system. A compact optical system for a digital photographing device comprises a diaphragm(STOP), a first lens(L1), a second lens(L2), and a third lens(L3) from an object side and satisfies a predetermined condition of 0.75< fL1/f <1.15. The fL1 is a paraxial focal length of a first lens. The f is a paraxial focal length of an overall optical system. Both sides of the first lens are aspheric, and the first lens has a positive refracting power. A convex side of the first lens faces the object. Both sides of the second lens are aspheric, and the second lens has a negative refracting power. A convex side of the second lens faces an image side. Both sides of the third lens are aspheric, and the third lens has the positive refracting power. The third lens is made of a plastic.
|
