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KR-20260066729-A - Optical laminates and display systems

KR20260066729AKR 20260066729 AKR20260066729 AKR 20260066729AKR-20260066729-A

Abstract

An optical laminate is provided that can achieve good weight reduction of VR goggles while improving visibility. The optical laminate comprises a polarizing member, a first phase difference member including a first λ/4 member, and an adhesive layer disposed between the polarizing member and the first phase difference member, wherein the coefficient of linear expansion from 25°C to 65°C in the absorption axis direction of the polarizing member is -1.9× 10⁻⁴ /°C or less, the first λ/4 member is a liquid crystal alignment solidification layer, and the elastic modulus of the adhesive layer at 85°C is 0.07MPa to 0.5MPa.

Inventors

  • 토쿠오카 사키미
  • 츠지 칸나

Assignees

  • 닛토덴코 가부시키가이샤

Dates

Publication Date
20260512
Application Date
20240830
Priority Date
20230920

Claims (15)

  1. A step of passing light representing an image emitted through a polarizing member through a first λ/4 member, and The step of passing the light that has passed through the first λ/4 member through a half mirror and a first lens member, and The step of passing the light that has passed through the half mirror and the first lens part through the second λ/4 member, and The step of reflecting the light that has passed through the second λ/4 member toward the half mirror in the reflective polarizing member, and A step of enabling light reflected from the reflective polarizing member and the half mirror to pass through the reflective polarizing member by the second λ/4 member. An optical laminate used in a display method comprising, The apparatus comprises the above-mentioned polarizing member, a first phase difference member including the above-mentioned first λ/4 member, and an adhesive layer disposed between the above-mentioned polarizing member and the first phase difference member, The coefficient of linear expansion of the above polarizing element in the absorption axis direction from 25°C to 65°C is -1.9× 10⁻⁴ /°C or less, and The above-mentioned first λ/4 member is a liquid crystal alignment solidification layer, and The elastic modulus of the above adhesive layer at 85°C is 0.07 MPa to 0.5 MPa, Optical laminate.
  2. In paragraph 1, An optical laminate in which the coefficient of linear expansion from 25°C to 65°C in the absorption axis direction of the polarization member of the first phase difference member when the optical laminate is made of the above, is 0.6× 10⁻⁴ /°C or greater.
  3. In paragraph 1, An optical laminate in which the thickness of the first λ/4 member is 5㎛ or less.
  4. In paragraph 1, The above-mentioned first phase difference member is an optical laminate comprising another phase difference layer.
  5. In paragraph 1, An optical laminate in which the absolute value of the difference between the linear expansion coefficient of the polarizing member in the absorption axis direction from 25°C to 65°C and the linear expansion coefficient of the first phase difference member in the absorption axis direction from 25°C to 65°C when the optical laminate is formed is 2.5× 10⁻⁴ /°C or greater.
  6. In paragraph 1, An optical laminate in which the absolute value of the difference between the linear expansion coefficient of the polarizing member in the transmission axis direction from 25°C to 65°C and the linear expansion coefficient of the first phase difference member in the transmission axis direction from 25°C to 65°C when the optical laminate is formed is 1.1× 10⁻⁴ /°C or greater.
  7. In paragraph 1, An optical laminate, wherein the ratio of the absolute value of the difference between the coefficient of linear expansion in the transmission axis direction of the polarizing member at 25°C to 65°C and the coefficient of linear expansion in the transmission axis direction of the first phase difference member at 25°C to 65°C when the optical laminate is formed, to the absolute value of the difference between the coefficient of linear expansion in the transmission axis direction of the polarizing member at 25°C to 65°C when the optical laminate is formed, is 0.6 or less.
  8. As a display system that displays images to a user, A display element including a display surface that emits light representing an image forward through a polarizing member, and A reflective polarizing member disposed in front of the above-mentioned display element and reflecting light emitted from the above-mentioned display element, and A first lens portion disposed in the optical path between the above-mentioned display element and the above-mentioned reflective polarizing member, and A half mirror disposed between the display element and the first lens portion, which transmits light emitted from the display element and reflects light reflected from the reflective polarizing member toward the reflective polarizing member, and A first λ/4 member disposed in the optical path between the above-mentioned display element and the above-mentioned half mirror, and It comprises a second λ/4 member disposed in the optical path between the half mirror and the reflective polarizing member, and An optical laminate comprising the above polarizing member, a first phase difference member including the above first λ/4 member, and an adhesive layer disposed between the polarizing member and the first phase difference member, The coefficient of linear expansion of the above polarizing element in the absorption axis direction from 25°C to 65°C is -1.9× 10⁻⁴ /°C or less, and The above-mentioned first λ/4 member is a liquid crystal alignment solidification layer, and The elastic modulus of the above adhesive layer at 85°C is 0.07 MPa to 0.5 MPa, Display system.
  9. In paragraph 8, A display system in which the coefficient of linear expansion at 25°C to 65°C in the absorption axis direction of the polarization member of the first phase difference member when the optical laminate is made of the above-mentioned optical laminate is 0.6× 10⁻⁴ /°C or greater.
  10. In paragraph 8, A display system in which the thickness of the first λ/4 member is 5㎛ or less.
  11. In paragraph 8, The above-mentioned first phase difference member further comprises another phase difference layer, a display system.
  12. In paragraph 8, A display system in which the absolute value of the difference between the coefficient of linear expansion of the polarizing member in the absorption axis direction from 25°C to 65°C and the coefficient of linear expansion of the first phase difference member in the absorption axis direction from 25°C to 65°C when the optical laminate is formed is 2.5× 10⁻⁴ /°C or greater.
  13. In paragraph 8, A display system in which the absolute value of the difference between the linear expansion coefficient of the polarizing member at 25°C to 65°C in the transmission axis direction and the linear expansion coefficient of the first phase difference member at 25°C to 65°C in the transmission axis direction of the polarizing member when the optical laminate is formed is 1.1× 10⁻⁴ /°C.
  14. In paragraph 8, A display system in which the ratio of the absolute value of the difference between the coefficient of linear expansion in the transmission axis direction of the polarizing member at 25°C to 65°C and the coefficient of linear expansion in the transmission axis direction of the first phase difference member at 25°C to 65°C when the polarizing member is made into the optical laminate, to the absolute value of the difference between the coefficient of linear expansion in the transmission axis direction of the polarizing member at 25°C to 65°C when the polarizing member is made into the optical laminate at 25°C to 65°C when the first phase difference member is made into the optical laminate at 25°C to 65°C when the polarizing member is made into the optical laminate at 0.6 or less.
  15. In paragraph 8, A display system in which the absolute value of the difference between the in-plane phase difference (a) of the first λ/4 member and the in-plane phase difference (b) of the second λ/4 member is 3.5 nm or less.

Description

Optical laminates and display systems The present invention relates to an optical laminate and a display system. Image display devices, such as liquid crystal display devices and electroluminescence (EL) display devices (e.g., organic EL display devices), are rapidly becoming widespread. In image display devices, optical components such as phase difference members and polarizing members are generally used to realize image display and improve image display performance (e.g., see Patent Document 1). These optical components can be integrated in advance and mounted on the image display device as an optical laminate. Recently, new applications for image display devices are being developed. For instance, display-equipped goggles (VR goggles) designed to realize Virtual Reality (VR) are beginning to be commercialized. As the use of VR goggles in various scenarios is being considered, there is a demand for features such as reduced weight and improved visibility. FIG. 1 is a schematic diagram showing the general configuration of a display system according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing the schematic configuration of an optical laminate according to one embodiment of the present invention. Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments. In order to make the explanation clearer, the drawings may schematically depict the width, thickness, shape, etc. of each part compared to the embodiments; however, this is merely an example and does not limit the interpretation of the present invention. Furthermore, in the drawings, the same or equivalent elements are given the same reference numerals, and redundant descriptions may be omitted. (Definition of Terms and Symbols) The definitions of terms and symbols in this specification are as follows. (1) Refractive index (nx, ny, nz) 'nx' is the refractive index in the direction where the refractive index in the plane is maximum (i.e., the ground axis direction), 'ny' is the refractive index in the direction perpendicular to the ground axis in the plane (i.e., the true axis direction), and 'nz' is the refractive index in the thickness direction. (2) In-plane phase difference (Re) 'Re(λ)' is the in-plane phase difference measured with light of wavelength λ nm at 23°C. For example, 'Re(550)' is the in-plane phase difference measured with light of wavelength 550 nm at 23°C. Re(λ) can be calculated by the formula: Re(λ)=(nx-ny)×d, where the thickness of the layer (film) is d(nm). (3) Phase difference in the thickness direction (Rth) 'Rth(λ)' is the phase difference in the thickness direction measured with light of wavelength λ nm at 23°C. For example, 'Rth(550)' is the phase difference in the thickness direction measured with light of wavelength 550 nm at 23°C. Rth(λ) can be calculated by the formula: Rth(λ)=(nx-nz)×d, where the thickness of the layer (film) is d(nm). (4) Nz coefficient The Nz coefficient can be calculated using the formula Nz = Rth/Re. (5) Angle When referring to angles in this specification, unless otherwise specified, said angle includes both clockwise and counterclockwise directions with respect to the reference direction. Thus, for example, '45°' means ±45°. Also, in this specification, 'approximately parallel' includes a range of 0°±10°, preferably within a range of 0°±5°, more preferably within a range of 0°±3°, and even more preferably within a range of 0°±1°. 'Approximately orthogonal' includes a range of 90°±10°, preferably within a range of 90°±5°, more preferably within a range of 90°±3°, and even more preferably within a range of 90°±1°. [Display System] FIG. 1 is a schematic diagram showing the general configuration of a display system according to one embodiment of the present invention. FIG. 1 schematically illustrates the arrangement and shape of each component of the display system (2). The display system (2) comprises a display element (12), a reflective part (14) including a reflective polarizing member, a first lens part (16), a half mirror (18), a first λ/4 member (20), a second λ/4 member (22), and a second lens part (24). The reflective part (14) is positioned at the front side, which is the display surface (12a) of the display element (12), and can reflect light emitted from the display element (12). The first lens part (16) is positioned in the optical path between the display element (12) and the reflective part (14), and the half mirror (18) is positioned between the display element (12) and the first lens part (16). The first λ/4 member (20) is positioned in the optical path between the display element (12) and the half mirror (18), and the second λ/4 member (22) is positioned in the optical path between the half mirror (18) and the reflection part (14). The display element (12) is, for example, a liquid crystal display or an organic EL display and includes a display surf