Polarizing plate, optical element, and liquid crystal display
First Claim
1. A polarizing plate comprising a polarizing film, wherein the polarizing film comprises a polyvinyl alcohol film having a thickness ranging from 85 μ
- m to 150 μ
m, dyed with a dichroic substance and stretched to 4-7 times, the polarizing film has a light transmittance ranging from 35% to 50% and a polarization degree of at least 80%;
a surface roughness in a direction perpendicular to the stretching axis of at most 0.04 μ
m based on a centerline average roughness; and
the polarizing film further comprises a transparent protective layer disposed on at least one surface of the polarizing film.
2 Assignments
0 Petitions
Accused Products
Abstract
A polyvinyl alcohol-based polarizing film is provided, and the polarizing film has excellent surface smoothness while the light transmittance and the polarization degree are improved due to the high stretch ratio. The polarizing film is obtained from a polyvinyl alcohol film having a thickness ranging from 85 μm to 150 μm by dyeing the film with a dichroic substance and stretching it to 4-7 times its original length. The polarizing film has a light transmittance ranging from 35% to 50% and a polarization degree of at least 80%, and the surface roughness in a direction perpendicular to the stretching axis is at most 0.04 μm based on a centerline average roughness. A transparent protective layer or a transparent protective plate comprising the transparent protective layer is formed on at least one surface of the polarizing film in order to provide a polarizing plate. The transparent protective layer can be subject to a pre-treatment selected from a hard-coat treatment and an anti-glare treatment. Additional optical layers are laminated on the polarizing plate in order to provide an optical element. A polarizing plate or an optical element comprising the above-mentioned polarizing film has an excellent light transmittance and polarization degree, so that stripe-shaped streaks inhibiting visibility will not be observed substantially even in a reflection mode.
19 Citations
22 Claims
-
1. A polarizing plate comprising a polarizing film,
wherein the polarizing film comprises a polyvinyl alcohol film having a thickness ranging from 85 μ - m to 150 μ
m, dyed with a dichroic substance and stretched to 4-7 times,the polarizing film has a light transmittance ranging from 35% to 50% and a polarization degree of at least 80%;
a surface roughness in a direction perpendicular to the stretching axis of at most 0.04 μ
m based on a centerline average roughness; and
the polarizing film further comprises a transparent protective layer disposed on at least one surface of the polarizing film. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- m to 150 μ
-
10. An optical element comprising a laminate of a polarizing plate and at least one optical layer,
the polarizing plate comprises a polarizing film comprising a polyvinyl alcohol film having a thickness ranging from 85 μ - m to 150 μ
m, dyed with a dichroic substance and stretched to 4-7 times, the polarizing film has a light transmittance ranging from 35% to 50% and a polarization degree of at least 80%;
a surface roughness in a direction perpendicular to the stretching axis of at most 0.04 μ
m based on a centerline average roughness; and
the polarizing film further comprises a transparent protective layer disposed on at least one surface of the polarizing film; and
the optical layer is selected from the group consisting of a retardation plate, a viewing angle compensating film, a photoconcentrating plate, a brightness-enhanced plate and a light diffusion plate. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
- m to 150 μ
-
22. A liquid crystal display comprising a liquid crystal cell and an optical element disposed on at least one surface of the liquid crystal cell,
wherein the optical element comprises a laminate of a polarizing plate and at least one optical layer, the polarizing plate comprises a polarizing film comprising a polyvinyl alcohol film having a thickness ranging from 85 μ - m to 150 μ
m, dyed with a dichroic substance and stretched to 4-7 times, the polarizing film has a light transmittance ranging from 35% to 50% and a polarization degree of at least 80%;
a surface roughness in a direction perpendicular to the stretching axis of at most 0.04 μ
m based on a centerline average roughness; and
the polarizing film further comprises a transparent protective layer disposed on at least one surface of the polarizing film; and
the optical layer is selected from the group consisting of a retardation plate, a viewing angle compensating film, a photoconcentrating plate, a brightness-enhanced plate and a light diffusion plate.
- m to 150 μ
Specification