US 12,135,425 B2
Waveguide structure, back light unit including the same, and display apparatus including the waveguide structure
Chilsung Choi, Suwon-si (KR); Hoon Song, Yongin-si (KR); and Hongseok Lee, Seoul (KR)
Assigned to SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed by SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed on Jul. 14, 2021, as Appl. No. 17/375,822.
Claims priority of application No. 10-2020-0132981 (KR), filed on Oct. 14, 2020.
Prior Publication US 2022/0113540 A1, Apr. 14, 2022
Int. Cl. G02B 6/00 (2006.01); F21V 8/00 (2006.01); G02B 5/18 (2006.01); G02B 5/30 (2006.01); G02B 6/27 (2006.01); G02B 27/01 (2006.01); G02B 30/25 (2020.01); G02B 30/33 (2020.01)
CPC G02B 27/0103 (2013.01) [G02B 5/1842 (2013.01); G02B 5/3058 (2013.01); G02B 6/0056 (2013.01); G02B 6/0061 (2013.01); G02B 6/0076 (2013.01); G02B 6/2726 (2013.01); G02B 30/25 (2020.01); G02B 30/33 (2020.01)] 17 Claims
OG exemplary drawing
 
1. A waveguide structure comprising:
an output grating;
a polarization conversion element disposed parallel to the output grating; and
a polarization separation element provided between the output grating and the polarization conversion element,
wherein the polarization separation element is configured to transmit, to the output grating, light having a first polarization direction among light incident on the polarization separation element, and reflect, to the polarization conversion element, light having a second polarization direction different from the light having the first polarization direction among the light incident on the polarization separation element to provide the light having the second polarization direction to the polarization conversion element, and
wherein the polarization separation element comprises:
a first area having a uniform first light transfer efficiency; and
a second area having a uniform second light transfer efficiency that is greater than the uniform first light transfer efficiency.