| 摘要 |
A method of producing a roll of a continuous web of an optical film laminate, usable in a process of laminating an optical film sheet including a polarizing film and formed to a size corresponding to that an optical panel to a surface of the optical panel being fed to a lamination position, is disclosed. The polarizing film is prepared by subjecting a laminate including a thermoplastic resin substrate and a PVA type resin layer formed on the substrate, to uniaxial 2-stage stretching to reduce a thickness of the PVA type resin layer to 10 μm or less, and causing a dichroic material to be absorbed in the PVA type resin layer. A carrier film is releasably attached to the continuous web of optical film laminate including the polarizing film, through an adhesive layer. A defect inspection is performed for the optical film laminate and the adhesive layer. |
| 主权项 |
1. A method of producing a roll of a continuous web of an optical film laminate, the roll being usable in a process of continuously feeding a rectangular-shaped optical panel having a short side and a long side to a lamination position, and laminating an optical film sheet including at least a polarizing film and formed to a size corresponding to dimensions of the long and short sides, to one of two surfaces of the optical panel fed to the lamination position, the method comprising steps of:
(a) forming a continuous web of an optical film laminate including at least a polarizing film which consists of a polyvinyl alcohol type resin layer and has a thickness of 10 μm or less and an absorption axis in a lengthwise direction of the optical film laminate, the polarizing film being formed by performing a stretching sub-step of subjecting a laminate comprising a continuous web of a thermoplastic resin substrate and a polyvinyl alcohol type resin layer formed on the substrate, to a uniaxial stretching in a lengthwise direction of the laminate to attain a stretching ratio of 5.0 to 8.5 to thereby reduce a thickness of the polyvinyl alcohol type resin layer to 10 μm or less, and an absorption sub-step of causing a dichroic material to be absorbed in the polyvinyl alcohol type resin layer, so as to have optical characteristics satisfying the following conditions: T≧42.5; and P≧99.5, wherein T is a single layer transmittance, and P is a polarization rate; (b) releasably attaching a carrier film to the optical film laminate through an adhesive layer under a condition that an adhesion force of the carrier film with respect to the adhesive layer is weaker than an adhesion force between the optical film laminate and the adhesive layer, to form a carrier film-attached optical film laminate; (c) performing a defect inspection for the optical film laminate and the adhesive layer, and, when a defect is detected therein, recording defect information about at least a position of the detected defect; (d) forming a plurality of slits in the carrier film-attached optical film laminate in a width direction perpendicular to the lengthwise direction, at lengthwise given intervals corresponding to one of the long and short sides of the optical panel, to extend from a surface of the optical film laminate to a depth reaching a surface of the carrier film facing the adhesive layer to thereby form an optical film laminate sheet between lengthwisely adjacent two of the slits, so that the carrier film-attached optical film laminate is formed as a continuous long sheet laminate having a structure in which a plurality of the sheets are continuously supported on the carrier film; (e) when it is determined based on the defect information that the plurality of optical film laminate sheets include the defect detected by the defect inspection, providing an identification for identifying the sheet including the defect as a defective sheet, to the sheet including the defect; and (f) winding the continuous long sheet laminate into a roll. |
