結像レンズ系および撮像装置および携帯情報端末装置

Japanese Patent JP6561714

B2

PROBLEM TO BE SOLVED: To provide a novel image forming lens system formed by arranging a first lens group having positive power on the object side of an aperture stop, and a second lens group having positive power on the image side thereof.SOLUTION: The image forming lens system is formed by arranging a first lens group G1 having positive power, an aperture stop S, and a second lens group G2 having positive power in order from the object side to the image side. The first lens group G1 is comprised of a 1a-th lens group G1a having negative power and arranged on the object side, and a 1b-th lens group G1b having positive power and arranged on the image side. The 1a-th lens group is formed by arranging a negative lens L11, a positive lens L12, and a negative lens L13 in the described order, and the 1b-th lens group is formed by arranging a positive lens L14, a positive lens L15, and a negative lens L16 in the described order. When shifting focus from an object at infinity to an object at a short distance, the first lens group is stationary while the second lens group moves toward the object side. A focal length f1 of the first lens group and a focal length f of the entire system satisfy a condition expressed as: 2.0