Imaging lens, camera and personal digital assistant

1. An imaging lens, comprising: in order from an object side

a first lens group including a positive refractive power; and

a second lens group having a negative refractive power,

the first lens group and the second lens group including a widest air space therebetween,

the first lens group including in order from the object side a negative first lens having a concave face on the object side, a positive second lens having a convex face on both sides, an aperture stop, a negative third lens having a concave face on the object side, a positive fourth lens having a convex face on an image side and a positive fifth lens having a convex face on the image side, and

the second lens group including a negative meniscus sixth lens having a concave face on the object side.

2. The imaging lens according to claim 1 , wherein a distance L from a most object-side face of the first lens group to an image face in a state focused on an infinite object and a focal length f of an entire system in a state focused on an infinite object satisfy the following condition (1):

1.2< L/f< 2.0  (1).

3. The imaging lens according to claim 2 , wherein the focal length f of the entire system in a state focused on an infinite object and a maximum image height Y′ satisfy the following condition (2):

0.50< Y′/f< 0.70  (2).

4. The imaging lens according to claim 1 , wherein a distance L from a most object-side face of the first lens group to an image face in a state focused on an infinite object and a distance D 1G-2G from a most image-side face of the first lens group to a most object-side face of the second lens group in a state focused on an infinite object satisfy the following condition (3):

0.15< D 1G-2G /L< 0.50  (3).

5. The imaging lens according to claim 1 , wherein a focal length of the second lens group f 2G and a focal length f of an entire system in a state focused on an infinite object satisfy the following condition (4):

−2.7< f 2G /f<− 1.2  (4).

6. The imaging lens according to claim 1 , wherein a curvature radius R L3F of an object-side face of the third lens and a distance D L2-L3 from an image-side face of the second lens to an object-side face of the third lens satisfy the following condition (5):

−2.5< R L3F /D L2-L3 <−1.0  (5).

7. The imaging lens according to claim 1 , wherein a synthetic focal length f L1-L2 of the first and second lenses and a focal length f of an entire system in a state focused on an infinite object to satisfy the following condition (6):

1.0< f L1-L2 /f< 1.8  (6).

8. The imaging lens according to claim 1 , wherein the fifth lens includes as an image-side face an aspheric shape in which a positive refractive power weakens in its peripheral portion.

9. The imaging lens according to claim 8 , wherein a distance L s-A from the aperture stop to the aspheric surface of the fifth lens and a distance L s-I from the aperture stop to the image face satisfy the following condition (7):

0.25< L S-A /L S-I <0.55  (7).

10. The imaging lens according to claim 1 , wherein the first lens is only moved when focusing on a close-range object.

11. A camera comprising the imaging lens according to claim 1 as a photographing optical system.

12. A personal digital assistant comprising the imaging lens according to claim 1 as a photographing optical system of a camera function portion.