OPTICAL FILM, ITS MANUFACTURING METHOD, POLARIZATION PLATE USING OPTICAL FILM AND DISPLAY DEVICE

PROBLEM TO BE SOLVED: To provide an optical film reduced in the restriction of a film manufacturing condition, sharply widened in the selection range of the film manufacturing condition and made excellent in transparency and flatness in the manufacture of the optical film wherein the stain on the surface of a metal support is removed in a short time without applying a flaw or a water mark to the surface of the metal support, the surface releasability of the support is enhanced, the surface of the support is made hard to stain and inorganic matter such as Ca or the like is perfectly peeled in a short time by blowing an ultrasonic irradiation liquid against the surface of the support using a megasonic ultrasonic irradiator using a washing agent, its manufacturing method, a polarization plate using the optical film and a display device. SOLUTION: In manufacturing the optical film, the surface of the metal support is washed by a washing apparatus using the washing agent, the liquid droplets remaining on the surface of the support is subsequently blown off by a liquid drainage device, the surface of the support is subjected to high energy surface treatment by an atmospheric pressure plasma device and a dope is subsequently cast over the surface of the support. COPYRIGHT: (C)2009,JPO&INPIT