Light absorption anisotropic film, optical film, and image display device

A light absorption anisotropic film formed of a composition containing a liquid crystal compound and a dichroic substance,

• wherein the light absorption anisotropic film has two main surfaces facing each other,
• an angle between a normal direction of a main surface of the light absorption anisotropic film and a transmittance central axis of the light absorption anisotropic film is 0° to 45°,
• in a case where the angle is 0°, the following requirement A1 is satisfied, and
• in a case where the angle is other than 0°, the following requirement B1 is satisfied,
• the requirement A1:
• an average polarization degree A of a polarization degree which is measured by allowing light having a wavelength of 450 nm to be incident from a direction tilted by 50° with respect to the normal direction, a polarization degree which is measured by allowing light having a wavelength of 550 nm to be incident from the direction tilted by 50° with respect to the normal direction, and a polarization degree which is measured by allowing light having a wavelength of 650 nm to be incident from the direction tilted by 50° with respect to the normal direction is 0.80 or more, and
• a retardation at a wavelength of 650 nm in the direction tilted by 50° with respect to the normal direction is less than 250 nm,
• the requirement B1:
• an average polarization degree B of a polarization degree which is measured by allowing light having a wavelength of 450 nm to be incident from a direction tilted by 50° on a normal direction side with respect to the transmittance central axis, a polarization degree which is measured by allowing light having a wavelength of 550 nm to be incident from the direction tilted by 50° on the normal direction side with respect to the transmittance central axis, and a polarization degree which is measured by allowing light having a wavelength of 650 nm to be incident from the direction tilted by 50° on the normal direction side with respect to the transmittance central axis is 0.80 or more, and
• a retardation at a wavelength of 650 nm in the direction tilted by 50° on the normal direction side with respect to the transmittance central axis is less than 250 nm,
• the polarization degree is a value represented by the following expression,
• Polarization
• ⁢
• degree
• =
• (
• TyO
• -
• TzO
• )
• (
• TyO
• +
• TzO
• )
• in the expression, Ty0 is a transmittance with respect to polarized light in a direction orthogonal to a direction obtained by orthographically projecting the transmittance central axis onto a plane orthogonal to a direction in which the light is incident, and Tz0 is a transmittance with respect to polarized light in a direction parallel to the direction obtained by orthographically projecting the transmittance central axis onto the plane orthogonal to the direction in which the light is incident.