US 11,789,185 B2
Reflective sheet
Makoto Ishiguro, Minamiashigara (JP); Hideki Kaneiwa, Minamiashigara (JP); Nobuhiko Ichihara, Minamiashigara (JP); Akira Yamamoto, Minamiashigara (JP); Ryuji Saneto, Minamiashigara (JP); and Michio Nagai, Minamiashigara (JP)
Assigned to FUJIFILM Corporation, Tokyo (JP)
Filed by FUJIFILM Corporation, Tokyo (JP)
Filed on Mar. 26, 2021, as Appl. No. 17/214,076.
Application 17/214,076 is a continuation of application No. PCT/JP2019/032419, filed on Aug. 20, 2019.
Claims priority of application No. 2018-183925 (JP), filed on Sep. 28, 2018.
Prior Publication US 2021/0223445 A1, Jul. 22, 2021
Int. Cl. G02B 5/02 (2006.01)
CPC G02B 5/0263 (2013.01) [G02B 5/0284 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A reflective sheet comprising:
a plurality of reflective layers that are laminated, the reflective layers being obtained by immobilizing a cholesteric liquid crystalline phase,
wherein in a cross-section of the reflective layer observed with a scanning electron microscope, at least a part of bright portions and dark portions derived from the cholesteric liquid crystalline phase has a flapping structure, the bright portions and the dark portions appearing in a cross-sectional view of the reflective layers observed with a scanning electron microscope,
at least one of the reflective layers has a pitch gradient structure that is a structure in which a helical pitch in a thickness direction gradually increases, and
in a case where a reflective layer that is formed on a surface other than a surface of the reflective layer among the plurality of reflective layers that are laminated is set as a lower reflective layer, a thickness of the lower reflective layer is less than those of other reflective layers than the lower reflective layer in the reflective layers.