US 12,235,567 B2
Imaging lens unit
Takeshi Yokoyama, Tokyo (JP)
Assigned to TOKYO VISIONARY OPTICS Co., Ltd., Tokyo (JP)
Filed by TOKYO VISIONARY OPTICS CO., LTD., Tokyo (JP)
Filed on Jul. 9, 2021, as Appl. No. 17/371,748.
Claims priority of application No. 2020-118126 (JP), filed on Jul. 9, 2020.
Prior Publication US 2022/0179289 A1, Jun. 9, 2022
Int. Cl. G03B 17/12 (2021.01); G02B 1/04 (2006.01); G02B 13/00 (2006.01)
CPC G03B 17/12 (2013.01) [G02B 1/04 (2013.01); G02B 13/0045 (2013.01)] 2 Claims
OG exemplary drawing
 
1. An imaging lens unit comprising:
a lens barrel formed of a resin material; and
seven plastic lenses housed in the lens barrel, wherein
the seven plastic lenses have aspheric surfaces on both surfaces,
a first plastic lens to a seventh plastic lens are arranged in order from an object side to an image side,
the first plastic lens to a fifth plastic lens have conical fitting slopes that are centered on an optical axis and are formed outside optical effective portions of the adjacent plastic lenses,
water absorption rates of materials of a third plastic lens and the fifth plastic lens are more than 0.2%, water absorption rates of materials of a second plastic lens and a fourth plastic lens are less than 0.1%, a water absorption rate of a material of the lens barrel is more than 0.4%, and
the fitting slopes of both sides of the third plastic lens are fitted to only outside fitting slopes of the second plastic lens and the fourth plastic lens, respectively, and the fitting slope of the fifth lens is fitted to only outside a fitting slopes of the fourth plastic lens.