IMAGING OPTICAL SYSTEM AND IMAGE CAPTURING DEVICE HAVING THE SAME

• Main Author: KAWAMURA KAZUTERU
• Format: Patent
• Language: English; Japanese
• Published: 24.10.2019
• 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

To provide an imaging optical system which offers superior operability and portability, high blur correction capability, and good correction for aberrations, and to provide an image capturing device having the same.SOLUTION: An imaging optical system comprises a first lens group having positive refractive power, second lens group having negative refractive power, third lens group having positive refractive power, fourth lens group having negative refractive power, and a rear lens group disposed on the most image side. A distance between the first lens group and the second lens group increases while focusing or zooming. The rear lens group comprises a positive lens and a negative lens. The first lens group and the third lens group are alway stationary in an optical axis direction. The fourth lens group moves toward the image side while shifting focus from an object at infinity to a nearby object. The third lens group comprises a positive lens and a negative lens. and also includes a blur correction lens group disposed in the third lens group. The imaging optical system satisfies the following conditional expressions (1), (2): 0.59≤|fMF/fMB|≤3.0, ...(1), 70.0≤νdFFp ...(2).SELECTED DRAWING: Figure 1 【課題】操作性と機動性に優れると共に、高いブレ補正効果を有し、収差が良好に補正された結像光学系及びそれを備えた撮像装置を提供する。【解決手段】結像光学系は、正屈折力の第１レンズ群と、負屈折力の第２レンズ群と、正屈折力の第３レンズ群と、負屈折力の第４レンズ群と、最も像側に配置された後側レンズ群と、を有し、フォーカス時又はズーム時、第１レンズ群と第２レンズ群との間隔が広がり、後側レンズ群は、正レンズと、負レンズと、を有し、第１レンズ群と第３レンズ群は、常時、光軸方向に移動せず、遠距離物体から近距離物体へのフォーカス時、第４レンズ群は像側に移動し、第３レンズ群は、正レンズと、負レンズと、を有し、ブレ補正レンズ群が、第３レンズ群に配置され、以下の条件式（１）、（２）を満足する。０．５９≦｜ｆMF／ｆMB｜≦３．０ （１）７０．０≦νｄFFp （２）【選択図】図１