| 摘要 |
PURPOSE: To make it possible to easily form a large-area film by using various kinds of resins and to control the refractive indices in triaxial directions in a film plane and thickness direction by including stages for compressing a resin film melted by heating in a transverse direction and stretching this resin film in a longitudinal direction in the state of maintaining the specified thickness of the resin film while extruding the resin film. CONSTITUTION: A process for producing this phase difference compensation plate has an extruder 2 for extruding the polysulfone resin film 1 with a suitable pressure, a die 3 for stretching or shrinking the resin film 1 and imparting the form of a film thereto and a cooling pipe 4 for cooling the resin film 1. The polysulfone resin film 1 (or polycarbonate resin film 5) melted by heating is axially compressed and longitudinally stretched in the state of maintaining the specified thickness while the resin film is extruded and, therefore, the large- area phase difference compensation plate controlled in the refractive index Nx in the extrusion direction, the refractive index Ny in the transverse direction and the refractive index Nz in the thickness direction of the resin film 1 to the relation Nx>Nz>Ny or Nx<Nz<Ny is easily and efficiently formed. |
