Method for producing optical film

摘要

The present invention relates to a method for producing an optical film, the optical film having the same molecule length in X-axis, Y-axis and Z-axis orientation, comprising the steps of: stretching the optical film along the X-axis; fixing the length of the optical film along the Y-axis; heating the optical film to above an extension temperature; shrinking the optical film along the X-axis; stretching the optical film along the Z-axis; and enabling the molecule length of the optical film along the X-axis to be longer than that along the Z-axis while the molecule length of the optical film along the Z-axis is longer than that along the Y-axis.