Patent ID: 8289632
Filing Date: 2012-10-16
Classification: G02B

Abstract:
1. A zoom lens comprising: three groups that are a negative first group, a positive second group, and a positive third group in order from an object side, the first group including a negative cemented lens formed by joining together, from the object side, a first lens formed by a negative single lens and a second lens formed by a positive single lens, the second group including, from the object side, a third lens formed by a positive single lens and a cemented lens formed by joining together a fourth lens formed by a positive single lens and a fifth lens formed by a negative single lens, the third group including a sixth lens formed by a positive single lens; the zoom lens satisfying following conditional expressions (1) to (3): where N1d is an index of refraction of the negative first lens forming the cemented lens in the first group with respect to a d-line, v2d is an Abbe number of the positive second lens forming the cemented lens in the first group, fw is focal length in a wide-angle end state, and f21 is focal length of the positive third lens located nearest to the object side within the second group.