Optical laminate and display device using the same

Abstract

To provide an optical laminate which uses biaxially stretched polyethylene terephthalate film as a base material and offers bending resistance and suppressed rainbow mura, and to provide an image display device using the same.SOLUTION: An optical laminate for use in image display devices is provided, the optical laminate comprising a light-transmissive substrate consisting of a biaxially stretched polyethylene terephthalate film and having in-plane birefringence, and an optical functional layer provided on one surface of the light-transmissive substrate, the optical functional layer having a surface with an arithmetic mean roughness Ra of 0.04 μm or greater, and irregularities on the surface with an average inclination angle θa of 0.30° or greater. The light-transmissive substrate has an in-plane retardation Re, defined by a formula (1): Re=(nx-ny)×d, of 2,000 nm to 7,500 nm, inclusive, where nx represents a refractive index in a slow axis direction, ny represents a refractive index in a fast axis direction, and d represents a thickness of the light-transmissive substrate.SELECTED DRAWING: Figure 1

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