US 12,449,582 B2
Light guide and virtual-image display device
Naoki Nakamura, Saitama (JP); Masahiro Itoh, Kanagawa (JP); Yoshifumi Sudoh, Kanagawa (JP); Susumu Momma, Kanagawa (JP); Shun Okazaki, Kanagawa (JP); Shigenobu Hirano, Kanagawa (JP); Yasuo Katano, Kanagawa (JP); Kenji Kameyama, Kanagawa (JP); Norikazu Igarashi, Kanagawa (JP); and Aino Hasegawa, Kanagawa (JP)
Assigned to RICOH COMPANY, LTD., Tokyo (JP)
Appl. No. 17/781,715
Filed by Naoki Nakamura, Saitama (JP); Masahiro Itoh, Kanagawa (JP); Yoshifumi Sudoh, Kanagawa (JP); Susumu Momma, Kanagawa (JP); Shun Okazaki, Kanagawa (JP); Shigenobu Hirano, Kanagawa (JP); Yasuo Katano, Kanagawa (JP); Kenji Kameyama, Kanagawa (JP); Norikazu Igarashi, Kanagawa (JP); and Aino Hasegawa, Kanagawa (JP)
PCT Filed Jan. 6, 2021, PCT No. PCT/IB2021/050052
§ 371(c)(1), (2) Date Jun. 2, 2022,
PCT Pub. No. WO2021/148892, PCT Pub. Date Jul. 29, 2021.
Claims priority of application No. 2020-007085 (JP), filed on Jan. 20, 2020; and application No. 2020-050321 (JP), filed on Mar. 19, 2020.
Prior Publication US 2023/0003931 A1, Jan. 5, 2023
Int. Cl. G02B 27/01 (2006.01); F21V 8/00 (2006.01)
CPC G02B 6/0036 (2013.01) [G02B 6/0031 (2013.01); G02B 6/0046 (2013.01); G02B 27/0172 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A device comprising:
an optical entrance having a plane to receive light;
a light guide to guide the light incident on the optical entrance with repeated reflection;
a light beam ejector to eject the light to an outside of the device; and
an extractor to reflect the light guided by the light guide toward the light beam ejector,
wherein the light guide includes:
a first reflection plane and a second reflection plane that face one another and are parallel with each other, and
at least one optical-path separator disposed between the first reflection plane and the second reflection plane,
wherein the at least one optical-path separator is detached from the optical entrance and disposed between the first reflection plane and the second reflection plane,
wherein the second reflection plane is disposed further from the light beam ejector than the optical-path separator, and
wherein the optical-path separator is to transmit the light that is reflected by the second reflection plane at a first reflection angle and travels toward the optical-path separator, and reflect, toward the second reflection plane, the light that is reflected by the second reflection plane at a second reflection angle wider than the first reflection angle and travels toward the optical-path separator.