| CPC G02F 1/133536 (2013.01) [G02F 1/133504 (2013.01)] | 12 Claims |
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1. An optical member comprising:
a first polarizing plate having an absorption axis and a transmission axis which are orthogonal to each other;
a reflective polarizing plate having a reflection axis and a transmission axis which are orthogonal to each other; and
an optical anisotropic diffusion layer which is provided between the first polarizing plate and the reflective polarizing plate and a linear transmittance which varies according to an incident light angle,
wherein:
light diffusivity of the optical anisotropic diffusion layer is defined by a plane which has a horizontal axis representing the incident light angle and a vertical axis representing the linear transmittance, the plane comprising a negative area on a left side with respect to an incident light angle 0° and a positive area on a right side with respect to the incident light angle 0°;
the optical anisotropic diffusion layer has a scattering central axis that is an axis of symmetry regarding the light diffusivity;
if a scattering central axis angle, which is an angle formed by a normal of the optical anisotropic diffusion layer and the scattering central axis, is θ, the scattering central axis angle θ is more than 0° and less than 90°;
if an incident light angle at which the linear transmittance becomes maximum in the negative area is α, the angle α is more than −90° and less than 0°;
if an incident light angle at which the linear transmittance becomes minimum between the scattering central axis angle θ and the angle α is β, the angle β is more than the angle α and less than the scattering central axis angle θ; and
a value k of the optical anisotropic diffusion layer is expressed as follows:
k=(linear transmittance at the scattering central axis angle θ−linear transmittance at the angle β)/linear transmittance at the angle α, wherein k is 0.18 or more.
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