| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a long stretched film having a predetermined orientation angle and Nz coefficient, in which variations in orientation angle and Nz coefficient are small across the full width of the film. SOLUTION: The method for manufacturing a long optically compensatory film includes a step of forming a first optical film satisfying n<SB>1z</SB><n<SB>1x</SB>and n<SB>1z</SB><n<SB>1y</SB>, or n<SB>1z</SB>>n<SB>1x</SB>and n<SB>1z</SB>>n<SB>1y</SB>, and a step of obtaining a second optical film having an average orientation angleθof 10-80°to a width direction in the position of the end of stretching in this step, by stretching the first optical film, wherein value for Nz coefficient of the second optical film represented by (n<SB>x</SB>-n<SB>z</SB>)/(n<SB>x</SB>-n<SB>y</SB>) is≥1.3 or≤-0.3, and wherein n<SB>1x</SB>, n<SB>1y</SB>, n<SB>1z</SB>, n<SB>x</SB>, n<SB>y</SB>and n<SB>z</SB>represent averages of refractive indexes of the first optical film and the second optical film to light having a wavelength of 550 nm, respectively. COPYRIGHT: (C)2008,JPO&INPIT
|
