US 11,815,711 B2
Broadband cascaded splitting film array waveguide and display system comprising same
Yong Li, Beijing (CN); Fei Wu, Beijing (CN); and Zhenrong Zheng, Beijing (CN)
Assigned to BEIJING LLVISION TECHNOLOGY CO., LTD., Beijing (CN)
Appl. No. 16/761,163
Filed by BEIJING LLVISION TECHNOLOGY CO., LTD., Beijing (CN)
PCT Filed Oct. 23, 2018, PCT No. PCT/CN2018/111509
§ 371(c)(1), (2) Date Jul. 31, 2020,
PCT Pub. No. WO2019/085796, PCT Pub. Date May 9, 2019.
Claims priority of application No. 201711062635.4 (CN), filed on Nov. 2, 2017.
Prior Publication US 2020/0363581 A1, Nov. 19, 2020
Int. Cl. G02B 27/01 (2006.01); F21V 8/00 (2006.01)
CPC G02B 6/0076 (2013.01) [G02B 27/0172 (2013.01); G02B 2027/0123 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A broadband cascaded splitting film array waveguide, comprising:
a plurality of glass substrates and a splitting film array, wherein each film of the splitting film array is sandwiched between two adjacent glass substrates, the structure of each film of the splitting film array is independent as α1Hβ1L/α2Hβ2L/. . . /αn−1Hβn−1L/αnHβnL, where H is a coating of high refractive index material and L is a coating of low refractive index material, the number of coatings in each film is 2n, spectral reflectances of respective films are R1, R2, . . . , RN respectively, transmittance of the glass substrates is T, and efficiencies n of the exiting lights on the films of the splitting film array are:
η1: R1*T
η2: R2*(1−R1)*T
η3: R3*(1−R2)*(1−R1)*T
ηN: RN*(1−RN)* . . . *(1−R1)*T,
η1=η2=. . . =ηN,
when the reflectance of the leftmost film is 1/P, the reflectances of the films are:
R1=1/(P+N−1)
R2=1/(P+N−2)
. . .
RN−1=1/(P+1)
RN=1/P .