US 12,222,527 B2
Light diffusion film
Sho Suzuki, Saitama (JP); Tatsuya Kato, Saitama (JP); and Kazutoshi Tachibana, Saitama (JP)
Assigned to KIMOTO CO., LTD., Saitama (JP)
Appl. No. 17/636,179
Filed by KIMOTO CO., LTD., Saitama (JP)
PCT Filed Sep. 23, 2020, PCT No. PCT/JP2020/035798
§ 371(c)(1), (2) Date Feb. 17, 2022,
PCT Pub. No. WO2021/084977, PCT Pub. Date May 6, 2021.
Claims priority of application No. 2019-199004 (JP), filed on Oct. 31, 2019.
Prior Publication US 2022/0299682 A1, Sep. 22, 2022
Int. Cl. G02B 5/02 (2006.01)
CPC G02B 5/02 (2013.01) [G02B 5/0268 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A light diffusion film comprising a base material film and a light diffusing layer, the light diffusing layer containing light diffusing particles having an average particle diameter t of 0.4 μm or more and a resin binder,
wherein a ratio (T/t) of an average film thickness T of the light diffusing layer to the average particle diameter t of the light diffusing particles, is 3.0 or more,
wherein, when the light diffusion film is used for thermoforming, a half-value angle H40 of the light diffusion film at an elongation rate of 40% is within a range of a value 25% lower than a value of a half-value angle H0 before elongation, or more and a value 25% higher than the value of the half-value angle H0 before elongation, or less, and
wherein an amount of the light diffusing particles loaded is 30% by mass or more and 80% by mass or less based on a total amount of solids in the light diffusing layer.