Title:
ズームレンズ
Document Type and Number:
Japanese Patent JP6758640
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a zoom lens which features a view angle in excess of 110 degrees at the wide-angle end and a back focus no less than three times a focal length at the wide-angle end, and which offers good optical performance while effectively minimizing imaging performance degradation due to manufacturing error and suppressing an increase in a manufacturing cost.SOLUTION: A zoom lens comprises a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having positive refractive power in order from the object side to the image side. When zooming from the wide-angle end to the telephoto end, all the lens groups move along an optical axis causing a distance between the first lens group and the second lens group to decrease and a distance between the second lens group and the third lens group to increase. The second lens group includes a biconvex lens located on the most object side, and an aperture stop is disposed within the second lens group or adjacent to an image side of the second lens group. The zoom lens satisfies predetermined conditions.SELECTED DRAWING: Figure 1
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Inventors:
Yutaka Uemura
Noriyuki Ogasawara
Takehisa Koyama
Noriyuki Ogasawara
Takehisa Koyama
Application Number:
JP2016174935A
Publication Date:
September 23, 2020
Filing Date:
September 07, 2016
Export Citation:
Assignee:
Sigma Co., Ltd.
International Classes:
G02B15/20; G02B13/04; G02B13/18
Domestic Patent References:
| JP2012022109A | ||||
| JP2014056133A | ||||
| JP2011017900A | ||||
| JP2016081005A | ||||
| JP2015028530A | ||||
| JP2014178388A | ||||
| JP2016224362A |