An optical display device which includes a display panel, and at least one polarizing film including a polyvinyl alcohol-based resin layer disposed on a viewing side with respect to the display panel, and having an optical arrangement forming a cross-Nicol relationship with regard to polarized light entering the polarizing film from the side of the display panel. The polarizing film is produced to have a thickness of 10 m or less, by a method comprising the steps of: forming a polyvinyl alcohol-based resin layer on a resin substrate; stretching the polyvinyl alcohol-based resin layer integrally with the resin substrate; and dyeing the polyvinyl alcohol-based resin layer using a dichroic material. The polarizing film is disposed in the optical display device in a state in which a surface of the polarizing film as a contact surface with the resin substrate during the production thereof is oriented toward a side opposite to the display panel.

An optical compensation film is disclosed herein, which is made by uniaxially or biaxially stretching of a multilayer film including a first polymer film having a refractive index profile satisfying the equations of (n.sub.x+n.sub.y)/2n.sub.z and |n.sub.xn.sub.y|<0.005 and a second polymer film having a refractive index profile satisfying the equations of (n.sub.x+n.sub.y)/2<n.sub.z and |n.sub.xn.sub.y|<0.005, wherein n.sub.x and n.sub.y represent in-plane refractive indices and n.sub.z the thickness-direction refractive index of the films, and wherein said optical compensation film has a positive in-plane retardation that satisfies the relations of 0.7<R.sub.450/R.sub.550<1 and 1<R.sub.650/R.sub.550<1.25, wherein R.sub.450, R.sub.550, and R.sub.650 are in-plane retardations at the light wavelengths of 450 nm, 550 nm, and 650 nm respectively.

An embodiment of the present invention provides a laminated polyester film including: a biaxially oriented polyester film which is produced by stretching an un-stretched polyester film in a first direction and stretching the resultant in a second direction perpendicular to the first direction along a film surface and has a small endothermic peak temperature of 160 C. or higher and 210 C. or lower, which is derived from a heat setting temperature measured by differential scanning calorimetry; and an undercoat layer which is formed by applying an undercoat layer forming composition onto one surface of the polyester film stretched in the first direction before being stretched in the second direction, and stretching the resultant in the second direction, and has a modulus of elasticity of 0.7 GPa or higher, a production method thereof, and a solar cell protective sheet and a solar cell module which include the laminated polyester film.

This invention is a highly insulating film, which is characterized by including a biaxially stretched film containing a styrene polymer having a syndiotactic structure as a main component, containing a thermoplastic amorphous resin Y having a glass transition temperature Tg by DSC of 130 C. or higher in an amount of 5% by mass or more and 48% by mass or less, and having a plane orientation coefficient (AP) represented by the following equation (1) of 0.027 or less: P=(Nx+Ny)/2Nz (1). In equation (1), Nx represents the minimum value of the refractive index in the plane direction of the film, Ny represents the refractive index in the direction perpendicular to Nx in the plane direction of the film, and Nz represents the refractive index in the thickness direction of the film.