IMAGING LENS SYSTEM AND IMAGING APPARATUS INCLUDING THE SAME

• Main Authors: FUJIKURA TAKASHI, KAWAMURA KAZUTERU
• Format: Patent
• Language: English; Japanese
• Published: 18.06.2015
• 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 an imaging lens system which facilitates a reduction in the length of the entire optical system and a reduction in the diameter, is excellent in mobility, and satisfactorily correcting aberrations, and an imaging apparatus including the same.SOLUTION: The imaging lens system includes an aperture stop S, and an image side lens-group group GI arranged on the image side of the aperture stop S. The image side lens-group group GI includes, in order from the aperture stop S to the image side, a first image side lens group having a negative refractive power, a second image side lens group having a positive refractive power, and a third image side lens group having a negative refractive power. Any one of the first image side lens group, the second image side lens group and the third image side lens group is a focus lens group which moves along the optical axis when focusing from an object at infinity to an object at a short distance. The imaging lens system satisfies the following conditional expression (1): (1) 0.06<|f/f|<0.4, where f is the focal length of the imaging lens system when focusing at an object at infinity, and fis the focal length of the focus lens group. 【課題】光学系全長の短縮化と小径化を容易にし、機動性に優れると共に、収差が良好に補正された結像レンズ系及びそれを備えた撮像装置を提供する。【解決手段】結像レンズ系は、開口絞りＳと、開口絞りＳよりも像側に配置された像側レンズ群グループＧＩと、を有し、像側レンズ群グループＧＩは、開口絞りＳから像側に向かって順に、負屈折力を有する第１像側レンズ群と、正屈折力を有する第２像側レンズ群と、負屈折力を有する第３像側レンズ群と、を有し、第１像側レンズ群、第２像側レンズ群及び第３像側レンズ群の何れかのレンズ群は、無限遠物体から近距離物体への合焦の際に光軸に沿って移動する合焦レンズ群であり、以下の条件式（１）を満足する。０.０６＜｜ｆfo／ｆ｜＜０．４（１）、ただし、ｆは、無限遠物体合焦時における結像レンズ系の焦点距離、ｆfoは、合焦レンズ群の焦点距離、である。【選択図】図１