| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a light collection sheet capable of obtaining a light collection sheet with reduced dimensional change due to heat. <P>SOLUTION: The manufacturing method of the light collection sheet according to the invention obtains a light collection sheet 1 which has a plurality of protrusions 1c arranged generally parallel with each other on at least one surface thereof. In the manufacturing method, using a pattern forming roll, a sheet of molten extruded thermoplastic resin is brought into crimp contact with the surface of the pattern forming roll to obtain an unstretched light collection sheet having a plurality of protrusions arranged generally parallel with each other on at least one surface thereof. After that, the unstretched light collection sheet is stretched in a longitudinal direction of the protrusions. When defining the glass transition temperature of the thermoplastic resin as Tg (°C), the unstretched light collection sheet is stretched as described above under a stretching temperature of (Tg-5)°C or more and (Tg+20)°C or less, and at a stretching ratio of more than 1 time and 3 times or less. <P>COPYRIGHT: (C)2012,JPO&INPIT |
