US 12,216,303 B2
Light-guide plate, manufacturing method for the same, light-guide plate module, and image display device
Hiroyuki Minemura, Tokyo (JP)
Assigned to HITACHI-LG DATA STORAGE, INC., Tokyo (JP)
Appl. No. 17/603,353
Filed by Hitachi-LG Data Storage, Inc., Tokyo (JP)
PCT Filed Feb. 13, 2020, PCT No. PCT/JP2020/005519
§ 371(c)(1), (2) Date Oct. 13, 2021,
PCT Pub. No. WO2020/255482, PCT Pub. Date Dec. 24, 2020.
Claims priority of application No. 2019-115048 (JP), filed on Jun. 21, 2019.
Prior Publication US 2022/0206207 A1, Jun. 30, 2022
Int. Cl. G02B 5/18 (2006.01); F21V 8/00 (2006.01)
CPC G02B 6/0016 (2013.01) [G02B 5/1861 (2013.01); G02B 6/0038 (2013.01); G02B 6/0065 (2013.01); G02B 2005/1804 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A light-guide plate comprising:
a substrate;
an incidence diffraction grating that diffracts incident light; and
an emission diffraction grating that emits light from the substrate, the light being diffracted by the incidence diffraction grating, the emission diffraction grating having two wave vectors that form an angle of 120°,
wherein
the emission diffraction grating is formed of a recessed/projected pattern formed on a surface of the substrate,
the recessed/projected pattern includes a first group of parallel straight lines and a second group of parallel straight lines intersecting the first group of parallel straight lines, and a pitch of the first group of parallel straight lines is equal to a pitch of the second group of parallel straight lines, and
a relationship between the pitch P of the first group of parallel straight lines and the second group of parallel straight lines and a pattern width W of the recessed/projected pattern is defined as W/P that is 0.15 or more and 0.85 or less.