US 11,953,711 B2
Diffractive light guide plate and display device including same
Jeong Ho Park, Daejeon (KR); Seong Min Park, Daejeon (KR); Sang Choll Han, Daejeon (KR); and Bu Gon Shin, Daejeon (KR)
Assigned to LG CHEM, LTD., Seoul (KR)
Appl. No. 17/299,281
Filed by LG CHEM, LTD., Seoul (KR)
PCT Filed Feb. 24, 2020, PCT No. PCT/KR2020/002591
§ 371(c)(1), (2) Date Jun. 2, 2021,
PCT Pub. No. WO2020/171666, PCT Pub. Date Aug. 27, 2020.
Claims priority of application No. 10-2019-0021188 (KR), filed on Feb. 22, 2019; and application No. 10-2020-0021640 (KR), filed on Feb. 21, 2020.
Prior Publication US 2022/0026619 A1, Jan. 27, 2022
Int. Cl. G02B 5/18 (2006.01); F21V 8/00 (2006.01); G02B 27/42 (2006.01)
CPC G02B 6/0016 (2013.01) [G02B 5/1819 (2013.01); G02B 6/0038 (2013.01); G02B 27/4205 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A diffractive light guide plate comprising:
a light guide unit configured to guide lights;
an input diffractive optical element configured to receive lights output from a light source and diffract the received lights to be guided on the light guide unit; and
two output diffractive optical elements disposed in a predetermined region of the light guide unit and having different linear grating patterns from each other,
wherein the two output diffractive optical elements are configured so that each one output diffractive optical element receives the lights from the input diffractive optical element and allows the received lights to be directed to the other output diffractive optical element by diffraction,
wherein the two output diffractive optical elements are configured so that each one output diffractive optical element receives lights from the other output diffractive optical element and allows the received lights to be output from the light guide unit by diffraction,
wherein the two output diffractive optical elements having different linear grating patterns from each other are alternately arranged in at least one dimension in a central region having at least a predetermined width within the predetermined region and partitioned longitudinally from a side adjacent to the input diffractive optical element to an opposite side thereto, and
wherein the two output diffractive optical elements are alternately arranged in two dimensions in the central region or all over the predetermined region.