US 12,147,045 B2
Light guide element and image display apparatus
Hiroshi Sato, Minamiashigara (JP); Katsumi Sasata, Minamiashigara (JP); and Yukito Saitoh, Minamiashigara (JP)
Assigned to FUJIFILM Corporation, Tokyo (JP)
Filed by FUJIFILM Corporation, Tokyo (JP)
Filed on Jun. 24, 2022, as Appl. No. 17/848,574.
Application 17/848,574 is a continuation of application No. PCT/JP2020/047505, filed on Dec. 18, 2020.
Claims priority of application No. 2019-239151 (JP), filed on Dec. 27, 2019.
Prior Publication US 2022/0326531 A1, Oct. 13, 2022
Int. Cl. G02B 27/01 (2006.01); F21V 8/00 (2006.01)
CPC G02B 27/0172 (2013.01) [G02B 6/0016 (2013.01); G02B 6/0035 (2013.01); G02B 6/0056 (2013.01); G02B 2027/0112 (2013.01); G02B 2027/0178 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A light guide element comprising:
a light guide plate that includes a first light guide layer and a second light guide layer; and
an incidence diffraction element that is laminated on the second light guide layer of the light guide plate and an emission diffraction element that is laminated on the second light guide layer of the light guide plate,
wherein in a case where a refractive index of the first light guide layer is represented by n1 and a refractive index of the second light guide layer is represented by n2 in the light guide plate,
n1<n2 is satisfied; and
wherein in a case where a thickness of the first light guide layer is represented by d1 and a thickness of the second light guide layer is represented by d2 in the light guide plate,
d1≥d2 is satisfied.