US 12,392,992 B2
Imaging optical system and camera
Naoto Nishimura, Osaka (JP); and Yutaro Sonoyama, Osaka (JP)
Assigned to Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
Filed by Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
Filed on May 19, 2022, as Appl. No. 17/748,312.
Claims priority of application No. 2021-088044 (JP), filed on May 26, 2021.
Prior Publication US 2022/0382015 A1, Dec. 1, 2022
Int. Cl. G02B 9/60 (2006.01); G02B 9/34 (2006.01); G02B 9/62 (2006.01); G02B 13/18 (2006.01); B60R 1/26 (2022.01)
CPC G02B 9/60 (2013.01) [G02B 9/34 (2013.01); G02B 9/62 (2013.01); G02B 13/18 (2013.01); B60R 1/26 (2022.01); B60R 2300/10 (2013.01); B60R 2300/20 (2013.01)] 6 Claims
OG exemplary drawing
 
1. An imaging optical system comprising:
a first lens having negative power and having a concave surface arranged to face an image;
a second lens having power;
a third lens having positive power;
a fourth lens having power; and
a fifth lens having power,
the first lens, the second lens, the third lens, the fourth lens, and the fifth lens being arranged in this order such as the first lens is located closer to an object than any other one of the second, third, fourth, and fifth lenses and that the fifth lens is located closer to the image than any other one of the first, second, third, and fourth lenses,
the imaging optical system satisfying conditions expressed by the following Inequalities (1) and (2):
R11/TTL<0.25   (1)
ThL1/Thsum<0.15   (2)
where R11 is a paraxial radius of curvature of an object-side surface of the first lens, TTL is a total optical length of the imaging optical system, ThL1 is a thickness of the first lens on an optical axis of the imaging optical system, and Thsum is a sum of respective thicknesses of all lenses, including the first, second, third, fourth, and fifth lenses, on the optical axis of the imaging optical system; and
the imaging optical system satisfying a condition expressed by the following Inequality (7):
−5.0<(R12+R11)/(R12−R11)<−1.5   (7)
where R12 is a paraxial radius of curvature of an image-side surface of the first lens.