US 11,892,766 B2
Projection screen
Lin Wang, Guangdong (CN); Xiaofeng Tang, Guangdong (CN); Wei Sun, Guangdong (CN); and Yi Li, Guangdong (CN)
Assigned to APPOTRONICS CORPORATION LIMITED, Guangdong (CN)
Appl. No. 17/597,434
Filed by APPOTRONICS CORPORATION LIMITED, Guangdong (CN)
PCT Filed Jun. 28, 2020, PCT No. PCT/CN2020/098466
§ 371(c)(1), (2) Date Jan. 5, 2022,
PCT Pub. No. WO2021/004303, PCT Pub. Date Jan. 14, 2021.
Claims priority of application No. 201910605057.7 (CN), filed on Jul. 5, 2019.
Prior Publication US 2022/0291579 A1, Sep. 15, 2022
Int. Cl. G03B 21/60 (2014.01); G03B 21/56 (2006.01); G03B 21/58 (2014.01); G03B 21/62 (2014.01); G03B 21/625 (2014.01)
CPC G03B 21/60 (2013.01) [G03B 21/56 (2013.01); G03B 21/58 (2013.01); G03B 21/62 (2013.01); G03B 21/625 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A projection screen, comprising:
a microstructure layer comprising a matrix layer and a microstructure unit formed on a surface of the matrix layer,
wherein the microstructure unit comprises triangular pyramid units arranged in an array, wherein each of the triangular pyramid units comprises a light output surface attached to and fixed to the surface of the matrix layer; wherein at least two of the triangular pyramid units that are arranged in a same row are identical to each other; wherein at least two triangular pyramid units of the triangular pyramid units that are arranged in a same column vary gradually; and wherein each of the taper angles forms between a base of one of the at least two triangular pyramid units that has the taper angle and an edge, parallel to a column direction, of the triangular pyramid unit, wherein the base is a surface of the triangular pyramid unit other than the light output surface and two surfaces that intersect to form the edge; and
wherein each of the taper angles of the at least two triangular pyramid units arranged along the column direction satisfy

OG Complex Work Unit Math
where θ denotes the taper angle of one of the at least two triangular pyramid units, α1 denotes an incident angle of image light, α4 denotes an emergent angle of the image light, and n denotes a refractive index of the triangular pyramid unit.