| 摘要 |
PROBLEM TO BE SOLVED: To provide a phase difference film hardly causing a change in phase difference of the deterioration of display quality due to stress acting on the film by laminating an isotropic film of a thermoplastic resin haring reverse sign of double refraction on stretched film of ano ther thermoplastic resin. SOLUTION: An isotropic film of a thermoplastic resin having reverse sign of double refraction is laminated on the stretched film of ano ther thermoplastic resin to obtain the objective phase difference film. The resin layers in the phase difference film compensate a change in phase difference caused by stress on the film. The ratio between the thicknesses of the laminated two thermoplastic resin films is preferably equal to the ratio between the reciprocals of the moduli of photoelasticity of the thermoplastic resins. The thermoplastic resin films are preferably films formed by flow-casting. Stretching is carried out by various uniaxial stretches such as roll stretching and zone stretching or biaxial stretching of their combination. |
