US 11,860,464 B2
Optical stack and liquid crystal display apparatus
Shintaro Yamada, Sakai (JP); Yukio Yoshida, Sakai (JP); Atsuko Maeda, Sakai (JP); Sumire Hombo, Sakai (JP); Hideki Nakagawa, Sakai (JP); Mitsuhiro Takeba, Sakai (JP); Toshihiro Yamashita, Sakai (JP); and Katsumi Kondo, Sakai (JP)
Assigned to SAKAI DISPLAY PRODUCTS CORPORATION, Sakai (JP)
Appl. No. 17/599,487
Filed by SAKAI DISPLAY PRODUCTS CORPORATION, Sakai (JP)
PCT Filed Mar. 27, 2020, PCT No. PCT/JP2020/014379
§ 371(c)(1), (2) Date Feb. 11, 2022,
PCT Pub. No. WO2020/196898, PCT Pub. Date Oct. 1, 2020.
Prior Publication US 2022/0187653 A1, Jun. 16, 2022
Int. Cl. G02F 1/1335 (2006.01)
CPC G02F 1/133504 (2013.01) [G02F 1/133514 (2013.01); G02F 1/133528 (2013.01); G02F 2202/04 (2013.01); G02F 2203/03 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An optical stack comprising:
a light scattering film converting light received at a light receiving surface into scattering light therein and then outputting the scattering light from a light output surface; and
a sheet provided on a light output surface side of the light scattering film, wherein
the light scattering film comprises:
a functional layer formed of a light-transmissive composition including an organic polymer compound and light scattering particles,
wherein the functional layer comprises a first surface receiving the light and a second surface from which the scattering light is output,
wherein the light scattering particles have an average particle size of 1.5 μm or larger,
wherein the functional layer further comprises a particle layer formed of light scattering particles having a content of 60% by volume or higher among the light scattering particles, the particle layer expanding along the first surface and being concentrated in a direction perpendicular to the first surface,
wherein the light scattering film is structured such that in a case that light having a normalized luminance of 0.5 or higher is incident on the first surface at an angle of incidence in a range of −32° to +32° with respect to the first surface, light having a normalized luminance of 0.33, among light to be output from the second surface, is output from the second surface at an angle of output in a range of −60° to −35° or +35° to +60° with respect to the second surface.