US 11,988,816 B2
Imaging lens including seven lenses of +−+0+−−, +−+0−+−or +−+0++−refractive powers
Koji Nitta, Tokyo (JP)
Assigned to TOKYO VISIONARY OPTICS Co., Ltd., Tokyo (JP)
Filed by TOKYO VISIONARY OPTICS CO., LTD., Tokyo (JP)
Filed on Aug. 2, 2021, as Appl. No. 17/391,968.
Application 17/344,177 is a division of application No. 16/547,033, filed on Aug. 21, 2019, granted, now 11,061,206.
Application 17/391,968 is a continuation of application No. 17/344,177, filed on Jun. 10, 2021.
Claims priority of application No. 2018-154545 (JP), filed on Aug. 21, 2018.
Prior Publication US 2021/0373296 A1, Dec. 2, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. G02B 13/00 (2006.01); G02B 9/64 (2006.01)
CPC G02B 13/0045 (2013.01) [G02B 9/64 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An imaging lens comprising in order from an object side to an image side,
a first lens with positive refractive power,
a second lens,
a third lens,
a fourth lens being a double-sided aspheric lens, an object-side surface and an image-side surface of said fourth lens being plane surfaces in a paraxial region,
a fifth lens,
a sixth lens, and
a seventh lens with negative refractive power having an image-side surface being concave in a paraxial region, wherein the image-side surface of said seventh lens is an aspheric surface having at least one pole point in a position off the optical axis, and following conditional expression (1) is satisfied:
10.00<vd2<29.00  (1)
where
vd2: an abbe number at d-ray of the second lens.