US 11,988,857 B2
Optical system
Takashi Yonemoto, Minamiashigara (JP); Yukito Saitoh, Minamiashigara (JP); Yohei Hamachi, Minamiashigara (JP); and Makoto Ishiguro, Minamiashigara (JP)
Assigned to FUJIFILM Corporation, Tokyo (JP)
Filed by FUJIFILM Corporation, Tokyo (JP)
Filed on Jul. 12, 2022, as Appl. No. 17/862,967.
Application 17/862,967 is a continuation of application No. PCT/JP2021/001336, filed on Jan. 15, 2021.
Claims priority of application No. 2020-004741 (JP), filed on Jan. 15, 2020; application No. 2020-053180 (JP), filed on Mar. 24, 2020; application No. 2020-072464 (JP), filed on Apr. 14, 2020; application No. 2020-082820 (JP), filed on May 8, 2020; application No. 2020-129658 (JP), filed on Jul. 30, 2020; and application No. 2020-171234 (JP), filed on Oct. 9, 2020.
Prior Publication US 2022/0373729 A1, Nov. 24, 2022
Int. Cl. G02B 5/30 (2006.01); C09K 19/50 (2006.01); G02B 27/00 (2006.01)
CPC G02B 5/3016 (2013.01) [C09K 19/50 (2013.01); G02B 27/0018 (2013.01)] 10 Claims
OG exemplary drawing
 
1. An optical system comprising:
an image display device that emits an image;
a linear polarizer through which light associated with the image passes;
a first quarter wavelength plate which receives the light from the linear polarizer;
a half mirror; and
a reflective polarizer; and
a second quarter wavelength plate provided between the reflective polarizer and the half mirror,
wherein retardance of the first quarter wavelength plate and retardance of the second quarter wavelength plate are equal to each other, and
wherein the first quarter wavelength plate and the second quarter wavelength plate are lamination type wavelength plates composed of the same optically anisotropic layers, the optically anisotropic layers are laminated to be disposed in a mirror symmetric way with the half mirror as a center, and the same optically anisotropic layers are disposed so that optic axes thereof are orthogonal to each other.