TELEPHOTO LENS AND IMAGING DEVICE HAVING THE TELEPHOTO LENS

• Main Author: KAWAMURA KAZUTERU
• Format: Patent
• Language: English; Japanese
• Published: 20.07.2017
• Subjects: ACCESSORIES THEREFOR; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES; APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM; CINEMATOGRAPHY; ELECTROGRAPHY; HOLOGRAPHY; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHOTOGRAPHY; PHYSICS

PROBLEM TO BE SOLVED: To provide a telephoto lens which is excellent in mobility and has an aberration corrected well, and an imaging device having the telephoto lens.SOLUTION: The present invention includes: a first lens group G1 with a positive refractive power; a second lens group G2 with a negative refractive power; and a third lens group G3. The first lens group has a front lens group with a positive refractive power and a back lens group located in ascending order of distance from an object, the second lens group moves at focusing, and the third lens group has a positive lens and a negative lens. The front lens group is formed of lenses located closer to an object than a specific negative lens satisfying the following conditional expression (a) is close to the object, and the lenses closer to the object than the specific negative lens include a plurality of positive lenses. The back lens group has a specific negative lens and a positive lens and satisfies the following conditional expression (1A) and (14): 0.5≤|f/fLn|(a), 0.015≤DGFGR/f≤0.25(1A), 0.19≤DGFairmax/DGF≤1.0(14).SELECTED DRAWING: Figure 1 【課題】機動性に優れると共に、収差が良好に補正された望遠レンズ及びそれを備えた撮像装置を提供する。【解決手段】正の屈折力を有する第１レンズ群Ｇ１と、負の屈折力を有する第２レンズ群Ｇ２と、第３レンズ群Ｇ３と、よりなり、第１レンズ群は、物体側から順に、正の屈折力を有する前側レンズ群と、後側レンズ群と、からなり、第２レンズ群は、合焦時に移動し、第３レンズ群は、正レンズと、負レンズと、を有し、前側レンズ群は、以下の条件式（ａ）を満足する所定の負レンズよりも物体側に位置するレンズで構成され、所定の負レンズよりも物体側に位置するレンズは、複数の正レンズを含み、後側レンズ群は、所定の負レンズと、正レンズと、を有し、以下の条件式（１Ａ）、（１４）を満足する。０．５≦｜ｆ／ｆLn｜（ａ）、０．０１５≦ＤGFGR／ｆ≦０．２５（１Ａ）、０．１９≦ＤGFairmax／ＤGF≦１．０（１４）【選択図】図１