ZOOM LENS AND IMAGING DEVICE

• Main Authors: IKEDA SHINKICHI, TANAKA TAKUYA
• Format: Patent
• Language: English; Japanese
• Published: 02.08.2018
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION

PROBLEM TO BE SOLVED: To provide a zoom lens achieving reduction in size and weight and high optical performance while suppressing changes in an angle of view upon focusing, and an imaging device including the zoom lens.SOLUTION: The zoom lens comprises, successively from an object side, a positive first lens group G1 that is immobile upon varying magnifications, at least two movable lens groups that move upon varying magnifications, and a positive final lens group that is immobile upon varying magnifications. The first lens group G1 comprises, successively from the object side, a negative first-a lens group G1a that is immobile upon focusing, a positive first-b lens group G1b that moves upon focusing, and a positive first-c lens group G1c that is immobile upon focusing. The first-a lens group G1a comprises, successively from the object side, a negative first lens L11, a positive second lens L12 having a convex surface on the object side, and a negative third lens L13, and at least one lens of the first lens L11 and the third lens L13 satisfies a predetermined conditional expression. The zoom lens as a whole satisfies a predetermined another conditional expression.SELECTED DRAWING: Figure 1 【課題】 合焦時の画角変化を抑えつつ、小型化および軽量化が達成され、高い光学性能が実現されたズームレンズ、およびこのズームレンズを備えた撮像装置を提供する。【解決手段】 物体側から順に、変倍時固定の正の第１レンズ群Ｇ１と、変倍時に移動する少なくとも２つの移動レンズ群と、変倍時に固定の正の最終レンズ群とからなり、第１レンズ群Ｇ１は、物体側から順に、合焦時に固定の負の第１ａレンズ群Ｇ１ａと、合焦時に移動する正の第１ｂレンズ群Ｇ１ｂと、合焦時に固定の正の第１ｃレンズ群Ｇ１ｃとからなり、第１ａレンズ群Ｇ１ａは、物体側から順に、負の第１レンズＬ１１と、物体側に凸面を向けた正の第２レンズＬ１２と、負の第３レンズＬ１３とからなり、第１レンズＬ１１と第３レンズＬ１３のうち少なくとも１枚のレンズは所定の条件式を満足し、全体として所定の他の条件式を満足するものとする。【選択図】図１