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US-20260126577-A1 - POLARIZING PLATE AND DISPLAY DEVICE

US20260126577A1US 20260126577 A1US20260126577 A1US 20260126577A1US-20260126577-A1

Abstract

A polarizing plate includes a polarizer and an optical film configured to suppress in-plane tint unevenness and azimuthal angle dependence when a display device is viewed obliquely in a black display state. The optical film has an in-plane retardation of 130 to 150 nm at a wavelength of 550 nm and includes, from a polarizer side, a first optically anisotropic layer, an intimate attachment layer, and a second optically anisotropic layer. The first optically anisotropic layer has an in-plane retardation of 150 to 240 nm at 550 nm, and a ratio of the in-plane retardation to a thickness of the first optically anisotropic layer is 0.07 to 0.116.

Inventors

  • Nobuyuki AKUTAGAWA
  • Shuhei OKUDA

Assignees

  • FUJIFILM CORPORATION

Dates

Publication Date
20260507
Application Date
20260107
Priority Date
20230731

Claims (8)

  1. 1 . A polarizing plate comprising: a polarizer; and an optical film, wherein an in-plane retardation of the optical film at a wavelength of 550 nm is 130 to 150 nm, the optical film includes a first optically anisotropic layer, an intimate attachment layer, and a second optically anisotropic layer from a polarizer side, an in-plane retardation of the first optically anisotropic layer at a wavelength of 550 nm is 150 to 240 nm, and a value obtained by dividing the in-plane retardation of the first optically anisotropic layer at a wavelength of 550 nm by a thickness of the first optically anisotropic layer is 0.07 to 0.116.
  2. 2 . The polarizing plate according to claim 1 , wherein a thickness unevenness of the intimate attachment layer is 5 to 35 nm.
  3. 3 . The polarizing plate according to claim 1 , wherein the in-plane retardation of the first optically anisotropic layer at the wavelength of 550 nm is 150 to 180 nm.
  4. 4 . The polarizing plate according to claim 1 , wherein the first optically anisotropic layer is a layer formed of a composition containing a disk-like liquid crystal compound.
  5. 5 . The polarizing plate according to claim 1 , wherein a thickness of the intimate attachment layer is 0.5 to 20 μm.
  6. 6 . The polarizing plate according to claim 1 , wherein the intimate attachment layer is an adhesive layer or a pressure-sensitive adhesive layer.
  7. 7 . The polarizing plate according to claim 1 , wherein the in-plane retardation of the optical film at the wavelength of 550 nm is 135 to 145 nm.
  8. 8 . A display device comprising: a display element; and the polarizing plate according to claim 1 .

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Continuation of PCT International Application No. PCT/JP2024/025286 filed on Jul. 12, 2024, which claims priority under 35 U.S.C. § 119 (a) to Japanese Patent Application No. 2023-124401 filed on Jul. 31, 2023, Japanese Patent Application No. 2023-217088 filed on Dec. 22, 2023, Japanese Patent Application No. 2024-001662 filed on Jan. 10, 2024, and Japanese Patent Application No. 2024-099468 filed on Jun. 20, 2024. The above applications are hereby expressly incorporated by reference, in their entirety, into the present application. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizing plate and a display device. 2. Description of the Related Art An optically anisotropic layer having refractive index anisotropy is applied to various applications such as an anti-reflection film of various display devices such as an organic electroluminescence (EL) display device, and an optical compensation film of a liquid crystal display device. For example, WO2022/045188A discloses an optical film in which three optically anisotropic layers exhibiting predetermined optical characteristics are laminated. SUMMARY OF THE INVENTION In recent years, in the display device, it is required to further reduce an in-plane tint unevenness and a tint change depending on a direction (azimuthal angle) in which the display device is viewed in a black display state from an oblique direction. As a result of studying the display device using the optical film disclosed in the above document, the present inventors have found that the display device may not satisfy a level required in recent years. The above-described in-plane tint unevenness is intended to mean that there are regions having different tints in a plane. In view of the above-described circumstances, an object of the present invention is to provide a polarizing plate which is applied to a display element to obtain a display device, in which an in-plane tint unevenness is unlikely to occur and tint azimuthal angle dependence is suppressed in a case where the display device is viewed in a black display state from an oblique direction. Another object of the present invention is to provide a display device. As a result of conducting an extensive investigation to achieve the objects, the present inventors have found that the objects can be achieved by the following constitution. [1] A polarizing plate comprising: a polarizer; andan optical film,in which an in-plane retardation of the optical film at a wavelength of 550 nm is 130 to 150 nm,the optical film includes a first optically anisotropic layer, an intimate attachment layer, and a second optically anisotropic layer from a polarizer side,an in-plane retardation of the first optically anisotropic layer at a wavelength of 550 nm is 150 to 240 nm, anda value obtained by dividing the in-plane retardation of the first optically anisotropic layer at a wavelength of 550 nm by a thickness of the first optically anisotropic layer is 0.07 to 0.116. [2] The polarizing plate according to [1],in which a thickness unevenness of the intimate attachment layer is 5 to 35 nm.[3] The polarizing plate according to [1] or [2],in which the in-plane retardation of the first optically anisotropic layer at the wavelength of 550 nm is 150 to 180 nm.[4] The polarizing plate according to any one of [1] to [3],in which the first optically anisotropic layer is a layer formed of a composition containing a disk-like liquid crystal compound.[5] The polarizing plate according to any one of [1] to [4],in which a thickness of the intimate attachment layer is 0.5 to 20 μm.[6] The polarizing plate according to any one of [1] to [5],in which the intimate attachment layer is an adhesive layer or a pressure-sensitive adhesive layer.[7] The polarizing plate according to any one of [1] to [6],in which the in-plane retardation of the optical film at the wavelength of 550 nm is 135 to 145 nm.[8] A display device comprising:a display element; andthe polarizing plate according to any one of [1] to [7]. According to the present invention, it is possible to provide a polarizing plate which is applied to a display element to obtain a display device, in which an in-plane tint unevenness is unlikely to occur and tint azimuthal angle dependence is suppressed in a case where the display device is viewed in a black display state from an oblique direction. According to the present invention, it is possible to provide a display device. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an example of a schematic cross-sectional view of an embodiment of the polarizing plate of the present invention. FIG. 2 is a view showing a relationship between an absorption axis of a polarizer and in-plane slow axes of optically anisotropic layers in the embodiment of the polarizing plate of the present invention shown in FIG. 1. FIG. 3 is a schematic view showing the relationship betwee