Abstract: Provided is a display device in which warping of a display panel is sufficiently reduced or prevented. The display device includes: a display panel; and a polarizer, the polarizer being provided with at least one notch that extends inward from an outer edge of the polarizer.

Abstract: An optical element includes, sequentially from a viewing surface side toward a back surface side: a viewing-surface-side polarizer; a retarder; and a back-surface-side polarizer, a transmission axis of the viewing-surface-side polarizer and a transmission axis of the back-surface-side polarizer being parallel to each other, the optical element having an average angle ? between an angle ?1 and an angle ?2 of greater than 0° and smaller than 90°, wherein the angle ?1 represents an angle formed by an optical axis of the retarder on a surface close to the back surface with the surface close to the back surface; and the angle ?2 represents an angle formed by an optical axis of the retarder on a surface close to the viewing surface with the surface close to the viewing surface.

Abstract: Provided is a liquid crystal display device having high luminance and high CR in a front direction and especially useful as a head-mounted liquid crystal display device, for example. The liquid crystal display device includes: a liquid crystal panel; an optical element; and a backlight, arranged in this order from a viewing surface side. The optical element includes a first polarizer, a retardation layer, and a second polarizer. The first polarizer, the retardation layer, and the second polarizer are arranged in this order from the viewing surface side. The first polarizer and the second polarizer are reflection polarizers. A reflection axis of the first polarizer and a reflection axis of the second polarizer are parallel to each other. In oblique directions at azimuths of 0°, 45°, and 90° at a polar angle of 60°, a polarization state of light incident on the first polarizer is elliptical polarization.

Abstract: Provided are an optical element that can achieve both color difference control and luminance reduction at an oblique viewing angle, and a liquid crystal display device including the optical element and having excellent display quality. The optical element includes: a first polarizer; a first phase difference layer; a second phase difference layer; and a second polarizer, the first polarizer, the first phase difference layer, the second phase difference layer, and the second polarizer being arranged in the stated order, the first phase difference layer satisfying the formula nx>ny?nz, the second phase difference layer satisfying the formula nz>nx?ny, the first polarizer and the second polarizer being linear polarizers, transmission axes of the first polarizer and the second polarizer being parallel to each other, a slow axis of the first phase difference layer being orthogonal to a polarization axis of the first polarizer.

Abstract: Provided are an optical element that can achieve both color difference control and luminance reduction at an oblique viewing angle, and a liquid crystal display device including the optical element and having excellent display quality. The optical element includes: a first polarizer; a first phase difference layer; a second phase difference layer; and a second polarizer, the first polarizer, the first phase difference layer, the second phase difference layer, and the second polarizer being arranged in the stated order, the first phase difference layer satisfying the formula nx>ny?nz, the second phase difference layer satisfying the formula nz>nx?ny, the first polarizer and the second polarizer being linear polarizers, transmission axes of the first polarizer and the second polarizer being parallel to each other, a slow axis of the first phase difference layer being orthogonal to a polarization axis of the first polarizer.

Abstract: Provided is a liquid crystal display device sequentially including: a first polarizer; a liquid crystal panel; a second polarizer; a biaxial retarder; a third polarizer; and a backlight including a light source and a prism sheet disposed closer to the viewing surface side than the light source is. The prism sheet includes prisms arranged in multiple columns on a surface close to the viewing surface side. The liquid crystal display has a light diffusion property curve having no side lobe or having a side lobe satisfying a ratio of a local maximum luminance to a local minimum luminance of 1.35 or less, the light diffusion property curve being obtained by plotting a luminance in a white display state in a direction perpendicular to ridge lines of the prisms against a polar angle.

Abstract: Provided is a liquid crystal display device sequentially including: a first polarizer; a liquid crystal panel; a second polarizer; a biaxial retarder; a third polarizer; and a backlight including a light source and a prism sheet disposed closer to the viewing surface side than the light source is. The prism sheet includes prisms arranged in multiple columns on a surface close to the viewing surface side. The liquid crystal display has a light diffusion property curve having no side lobe or having a side lobe satisfying a ratio of a local maximum luminance to a local minimum luminance of 1.35 or less, the light diffusion property curve being obtained by plotting a luminance in a white display state in a direction perpendicular to ridge lines of the prisms against a polar angle.

Abstract: Provided is a liquid crystal display device having high luminance and high CR in a front direction and especially useful as a head-mounted liquid crystal display device, for example. The liquid crystal display device includes: a liquid crystal panel; an optical element; and a backlight, arranged in this order from a viewing surface side. The optical element includes a first polarizer, a retardation layer, and a second polarizer. The first polarizer, the retardation layer, and the second polarizer are arranged in this order from the viewing surface side. The first polarizer and the second polarizer are reflection polarizers. A reflection axis of the first polarizer and a reflection axis of the second polarizer are parallel to each other. In oblique directions at azimuths of 0°, 45°, and 90° at a polar angle of 60°, a polarization state of light incident on the first polarizer is elliptical polarization.

Abstract: Provided is a liquid crystal display device in which reflection and light leakage from oblique directions are reduced or prevented. The liquid crystal display device includes, sequentially in the following order from a back surface side: a first polarizer; a liquid crystal panel; a second polarizer; a first retardation layer; and a third polarizer, wherein light transmitted in an oblique direction between the second polarizer and the third polarizer is elliptically polarized light.

Abstract: An optical element includes, sequentially from a viewing surface side toward a back surface side: a viewing-surface-side polarizer; a retarder; and a back-surface-side polarizer, a transmission axis of the viewing-surface-side polarizer and a transmission axis of the back-surface-side polarizer being parallel to each other, the optical element having an average angle ? between an angle ?1 and an angle ?2 of greater than 0° and smaller than 90°, wherein the angle ?1 represents an angle formed by an optical axis of the retarder on a surface close to the back surface with the surface close to the back surface; and the angle ?2 represents an angle formed by an optical axis of the retarder on a surface close to the viewing surface with the surface close to the viewing surface.