Optical layered body and liquid crystal display device using optical layered body
There is provided an optical laminate that can achieve a liquid crystal display apparatus in which the occurrence of moire is suppressed, and which is excellent in brightness and viewing angle characteristic. An optical laminate of the present invention includes in the stated order: a polarizer; a light-diffusing pressure-sensitive adhesive layer; a matte layer; and a louver layer. The louver layer has light-transmitting portions each having a trapezoidal section arrayed along a film plane, and light-absorbing portions each having a trapezoidal section arrayed between the light-transmitting portions. A haze value H of the light-diffusing pressure-sensitive adhesive layer and a bias angle B of the louver layer satisfy relationships represented by the following expressions (1) to (3): 2≤ B ≤6 (1) 20≤ H ≤60 (2) B×H ≥40 (3) where the bias angle means a tilt angle of each of the trapezoidal sections with respect to a normal direction.
1. An optical laminate, comprising, in this order:
a polarizer;
a light-diffusing pressure-sensitive adhesive layer;
a matte layer; and
a louver layer,
wherein the louver layer has light-transmitting portions each having a trapezoidal section arrayed along a film plane, and light-absorbing portions each having a trapezoidal section arrayed between the light-transmitting portions, and
wherein a haze value H of the light-diffusing pressure-sensitive adhesive layer and a bias angle B of the louver layer satisfy relationships represented by the following expressions (1) to (3):
2≤ B≤ 6 (1)
20≤ H≤ 60 (2)
B×H≥ 40 (3)
where the bias angle means a tilt angle of each of the trapezoidal sections with respect to a normal direction.
2. The optical laminate according to claim 1 ,
wherein the light-diffusing pressure-sensitive adhesive layer contains a pressure-sensitive adhesive and light-diffusible fine particles dispersed in the pressure-sensitive adhesive,
wherein the pressure-sensitive adhesive has a refractive index of from 1.47 to 1.60, and
wherein the light-diffusible fine particles each have a refractive index lower than the refractive index of the pressure-sensitive adhesive.
3. The optical laminate according to claim 2 , wherein a refractive index difference between each of the light-diffusible fine particles and the pressure-sensitive adhesive is more than 0 and 0.2 or less.
4. The optical laminate according to claim 2 , wherein the light-diffusible fine particles comprise silicone resin fine particles.
5. The optical laminate according to claim 2 , wherein the light-diffusible fine particles have a volume-average particle diameter of from 1 μm to 4 μm.
6. The optical laminate according to claim 1 , wherein a surface of the matte layer has an arithmetic average roughness Ra of 20 nm or more.
7. The optical laminate according to claim 6 ,
wherein the matte layer contains fine particles, and
wherein the fine particles have a mode particle diameter in a range of ±50% of a thickness of the matte layer.
8. A liquid crystal display apparatus, comprising:
a liquid crystal cell; and
the optical laminate of claim 1 arranged on an opposite side of the liquid crystal cell to a viewer side,
wherein the polarizer of the optical laminate is arranged on a liquid crystal cell side.