| 摘要 |
PROBLEM TO BE SOLVED: To provide an imaging lens which is suitable to an image pickup device such as a single lens reflex camera, compact in size, less variable in the whole length, and optimal to motor drive in a lens barrel and the like. SOLUTION: The imaging lens SL, which is mounted on a digital single-lens reflex camera 1 or the like, is composed of a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having negative refractive power, wherein these lens groups are sequentially arranged in this order from the object side. The first lens group G1 is composed of a first partial group La having negative refractive power and a second partial group Lb having positive refractive power, these part groups being sequentially arranged in this order from the object side. The second lens group G2 is composed of a third partial group Lc having negative refractive power which consists of a positive lens L21, a negative lens L22 and a positive lens L23, these lenses being sequentially arranged in this order from the object side. Then, when focusing is made on a close distance object point from an infinite distance, the first lens group G1 and the second lens group G2 move to the object side. COPYRIGHT: (C)2011,JPO&INPIT |
