Title:
WIDE-ANGLE LENS
Document Type and Number:
WIPO Patent Application WO/2019/021831
Kind Code:
A1
Abstract:
To provide a wide-angle lens whereby a wider angle can be achieved while a shorter distance between object and image is achieved in a lens system overall or productivity of a second lens is maintained in a lens configuration having five elements in four groups. A wide-angle lens 100 has a lens configuration having five elements in four groups. A second lens, a third lens 30, a fourth lens 40, and a fifth lens 50 are plastic lenses, the fourth lens 40 and the fifth lens 50 constituting a cemented lens 60. The effective radius R22 of a lens surface 22 on the image side Lb of the second lens 20, the distance d23 from the center of the lens surface 22 on the image side Lb of the second lens 20 to the center of a lens surface 31 on the object side La of the third lens 30, the focal length f0 of the lens system overall, and the thickness d3 of the center of the third lens 30 satisfy the following conditions: 0.5 < R22/d23 < 1.5 and 2.0 < d3/f0 < 5.0.
Inventors:
KANZAKI YOSUKE (JP)
Application Number:
PCT/JP2018/026252
Publication Date:
January 31, 2019
Filing Date:
July 12, 2018
Export Citation:
Assignee:
NIDEC SANKYO CORP (JP)
International Classes:
G02B13/04; G02B13/18
Foreign References:
| CN106468818A | 2017-03-01 | |||
| CN106468819A | 2017-03-01 | |||
| JP2009063877A | 2009-03-26 | |||
| JP2014228570A | 2014-12-08 | |||
| JP2013205715A | 2013-10-07 | |||
| JP2017181857A | 2017-10-05 |
Download PDF: