Optical film and eyewear

Patent metadata

Field	Value
Publication number	US-2022004028-A1
Application number	US-202117480559-A
Country	US
Kind code	A1
Filing date	Sep 21, 2021
Priority date	Mar 28, 2019
Publication date	Jan 6, 2022
Grant date	—

Abstract

The present disclosure relates to an optical film including an optical laminate in which two or more light reflection layers having center wavelengths of reflection different from each other are laminated and a polarizing element layer. The two or more light reflection layers are selected from at least one light reflection layer RPRL having a center wavelength of selective reflection in the range of 400 nm or more and 900 nm or less, in which a cholesteric liquid crystal phase with a right-handed spiral structure having right-handed circularly polarized light reflectivity is fixed, and at least one light reflection layer LPRL having a center wavelength of selective reflection in the range of 400 nm or more and 900 nm or less, in which a cholesteric liquid crystal phase with a left-handed spiral structure having left-handed circularly polarized light reflectivity is fixed. Light reflection layer RPRL and light reflection layer LPRL each have a center wavelength of selective reflection shifted from that of a light reflection layer adjacent to each other by an interval of 40 nm or more and 500 nm or less, and the maximum reflectance of optical laminate is 50% or less.

First claim

What is claimed is:

1 . An optical film comprising:
an optical laminate in which two or more light reflection layers having center wavelengths of reflection different from each other are laminated; and a polarizing element layer, wherein the two or more light reflection layers are selected from at least one light reflection layer RPRL having a center wavelength of selective reflection in a range of 400 nm or more and 900 nm or less, in which a cholesteric liquid crystal phase with a right-handed spiral structure having a right-handed circularly polarized light reflectivity is fixed, and at least one light reflection layer LPRL having a center wavelength of selective reflection in a range of 400 nm or more and 900 nm or less, in which a cholesteric liquid crystal phase with a left-handed spiral structure having a left-handed circularly polarized light reflectivity is fixed, the light reflection layer RPRL and the light reflection layer LPRL each have a center wavelength of selective reflection shifted from that of a light reflection layer adjacent to each other by an interval of 40 nm or more and 500 nm or less, and the maximum reflectance of the optical laminate is 50% or less.

2 . The optical film according to claim 1 , wherein the two or more light reflection layers comprise both of the light reflection layer RPRL and the light reflection layer LPRL.

3 . The optical film according to claim 1 , wherein a degree of polarization is 90% or more.

4 . The optical film according to claim 1 , wherein a degree of polarization is 95% or more.

5 . The optical film according to claim 1 , wherein a haze value (Hz) is less than 0.5%.

6 . The optical film according to claim 1 wherein a difference between a maximum reflectance and an average reflectance of the optical laminate is 30% or less and a difference between an average reflectance and a minimum reflectance of the optical laminate is 15% in a wavelength region of 450 nm or more and 750 nm or less.

7 . Eyewear comprising the optical film according to claim 1 .

Assignees

• Nippon Kayaku Kk

Inventors

• Hayasaki Tomoyuki
• Yahagi Yoshiyuki

Classifications

• G02B5/3041 Primary

  comprising multiple thin layers, e.g. multilayer stacks · CPC title

• G02C7/12 Primary

  Polarisers · CPC title

• G02F1/133543 Primary

  Cholesteric polarisers · CPC title

• B32B7/023

  Optical properties · CPC title

• G02F1/133541

  Circular polarisers · CPC title