Title:
OPTICAL SYSTEM AND IMAGING APPARATUS
Document Type and Number:
Japanese Patent JP2021124629
Kind Code:
A
Abstract:
To provide a small optical system which has a large aperture, allows downsizing of a focus group, can suppress aberration fluctuation in focusing, and has excellent optical performance, and an imaging apparatus.SOLUTION: An optical system is constituted by, in sequence from an object side, a first lens group (G1) having positive refractive power, a second lens group (G2) having positive refractive power, and a third lens group (G3) having negative refractive power. In focusing from an infinite distance object to a finite distance object, the first lens group G1 and the third lens group G3 are fixed with respect to an image surface, whilst the second lens group G2 is moved in an optical axis direction. A lens surface of the second lens group G2 arranged closest to the object is convex toward the object side. The second lens group G2 is constituted by, in sequence from the object side, a second A part group G2A, a diaphragm, and a second B part group G2B, and satisfies a predetermined conditional expression. Additionally, an imaging apparatus includes the optical system and an image pickup device.SELECTED DRAWING: Figure 1
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Inventors:
TAKAHASHI JUN
SAKAI TAKAHIKO
SAKAI TAKAHIKO
Application Number:
JP2020018648A
Publication Date:
August 30, 2021
Filing Date:
February 06, 2020
Export Citation:
Assignee:
TAMRON KK
International Classes:
G02B13/00; G02B13/18
Attorney, Agent or Firm:
Yoshihiro Uemura
Hiroko Negishi
Hiroko Negishi