US 12,298,502 B2
Virtual image display device
Osamu Yokoyama, Shiojiri (JP)
Assigned to SEIKO EPSON CORPORATION, Tokyo (JP)
Filed by SEIKO EPSON CORPORATION, Tokyo (JP)
Filed on Jul. 30, 2021, as Appl. No. 17/389,358.
Claims priority of application No. 2020-129075 (JP), filed on Jul. 30, 2020.
Prior Publication US 2022/0035157 A1, Feb. 3, 2022
Int. Cl. G02B 27/01 (2006.01); F21V 8/00 (2006.01); G02B 5/18 (2006.01); G02B 5/32 (2006.01); G02B 27/42 (2006.01)
CPC G02B 27/0101 (2013.01) [G02B 5/1866 (2013.01); G02B 5/32 (2013.01); G02B 6/005 (2013.01); G02B 27/4205 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A virtual image display device comprising:
an imaging light emitting device configured to emit imaging light;
a light-guiding member configured to guide the imaging light emitted from the imaging light emitting device; and
a diffraction element provided at an emitting portion of the light-guiding member emitting the imaging light and configured to emit the imaging light by diffraction, wherein
in the diffraction element, a light amount difference between a first component light of the imaging light and a second component light of the imaging light is equal to or less than 20%, the first component light being emitted at a first angle, and the second component light being emitted at a second angle different from the first angle,
the diffraction element has a central portion and a peripheral portion, the central portion emitting a part of the imaging light and diffracting another of the imaging light, and the peripheral portion emitting a part of the imaging light diffracted by the central portion, and
in the diffraction element, a light amount difference between a first light and a second light of the imaging light is equal to or less than 20%, the first light being emitted from the central portion, the second light being emitted from the peripheral portion.