Patent ID: 6888599

Claim:
An optical film in which at least one layer of a cholesteric liquid crystal layer ( 1 ) and a retardation layer ( 2 ) are laminated, wherein an in-plane retardation of the retardation layer ( 2 ): (nx 1 âˆ’ny 1 )Ã—Dre is 5 nm or less, a virtual thickness direction retardation: RZch=DchÃ—(neâˆ’no)/2 calculated from following Dch, ne, and no, a thickness direction retardation: RZre=DreÃ—(npâˆ’nz) calculated from Dre, np, and nz shown below, have a relationship of RZre/(âˆ’RZch)=0.05 through 0.35.