| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high performance imaging lens that has a half angle of view of about 28 to 36 degrees, an F number smaller than 2.8, a small size with a fewer composing lenses, and various aberrations sufficiently reduced by an inner focus system, and is suitable for a digital camera. <P>SOLUTION: The imaging lens comprises, in order from an object side to an image side, a positive first lens group G1, an aperture stop S, a positive second lens group G2, and a negative third lens group G3. When focusing from an infinity object to a short-distance object, the imaging lens moves only the second lens group G2 toward the object side. The first lens group G1 has one positive lens and one negative lens. The second lens group G2 comprises, in order from the object side to the image side, a negative second-first lens with a concave face oriented toward the object side, a positive second-second lens with a convex face oriented toward the image side, and a positive second-third lens with a convex face oriented toward the image side. The third lens group G3 comprises a negative lens with a concave face oriented toward the object side. <P>COPYRIGHT: (C)2013,JPO&INPIT |
