Patent ID: 11860464
Assignee: SAKAI DISPLAY PRODUCTS CORPORATION
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
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.