Abstract: There is provided an optical sheet stack which includes a first optical sheet having a large number of irregularities consecutively arranged on one surface thereof, and a second optical sheet stacked thereon. In the optical sheet stack, the second optical sheet has, on a bonding surface thereof, an adhesive layer bonded with apexes of the irregularities, and while assuming pitch of arrangement of the irregularities as P, and width of bonding of each apex of the irregularities bonded to the adhesive layer as Pw, the relation of 0<Pw/P?0.2 is satisfied.

Abstract: An optical element covering member includes one or more optical elements, a support medium for supporting the one or more optical elements, and a covering member for covering the one or more optical elements and the support medium. At least one out of the one or more optical elements is a reflective polarizer, and the covering member has at least a region, through which the light inputted from a light source is emitted to a liquid crystal panel, the region having a phase difference lag of not more than 1/50? of a measured wavelength, with respect to an optical axis of the reflective polarizer.

Abstract: A optical element covering member includes one or more optical elements, a support medium for supporting the one or more optical elements, and a cover material for covering the one or more optical elements and the support medium. The cover material includes a layer of block copolymer of vinyl aromatic hydrocarbon and conjugate diene, and a mass ratio of the vinyl aromatic hydrocarbon to the conjugate diene stands at 95:5 to 5:95.

Abstract: An optical element covering member is provided which can suppress degradation in display performance caused by warping and undulation. The optical element covering member includes at least one optical element, a support medium supporting the optical element; and a covering member covering the optical element and the support medium. In the above optical element covering member, the covering member has a Vicat softening point of more than 85° C., and at least one surface of the covering member, which covers the support medium, has a coefficient of thermal expansion in the range of 85% to 160% of the coefficient of thermal expansion of the support medium.

Abstract: An optical packaged body capable of preventing generation of a wrinkle, deflection, and warpage, capable of being thinned is provided. The optical package body includes a support medium and a packaging film that covers the support medium in a state of being applied with shrinkage force. The packaging film has an optical function section that acts on light from a light source in at least one of a first region into which the light from the light source enters and a second region from which the light from the light source is emitted after passing through the optical packaged body when the light source is arranged on one face side of the optical packaged body.