Patent ID: 6859242

Claim:
A polarizing plate which comprises a polymer film having a slow axis and a polarizing membrane having a transmission axis, said polymer film and said polarizing membrane being arranged to orient the slow axis of the polymer film essentially at an angle of 45° to the transmission axis of the polarizing membrane, wherein the polarizing membrane has a transmittance of 30 to 50% and a polarizing degree of 90 to 100%, wherein when light having a wavelength of 450 nm is incident on the polarizing membrane, the ratio of the transmittance in a direction parallel to the transmission axis to the transmittance in a direction perpendicular to the transmission axis satisfies the following formula (I), and wherein when light having a wavelength of 590 nm is incident on the polarizing membrane, the ratio of the transmittance in a direction parallel to the transmission axis to the transmittance in a direction perpendicular to the transmission axis satisfies the following formula (II): 0.6 ≦T //(450)/ T ⊥(450)≦1.5 (I) 0.6 ≦T //(590)/ T ⊥(590)≦1.5 (II) in which T//(450) is the transmittance in the direction parallel to the transmission axis when light having a wavelength of 450 nm is incident on the polarizing membrane; T⊥(450) is the transmittance in the directions perpendicular to the transmission axis when light having a wavelength of 450 nm is incident on the polarizing membrane; T//(590) is the transmittance in the direction parallel to the transmission axis when light having a wavelength of 590 nm is incident on the polarizing membrane; T⊥(590) is the transmittance in the direction perpendicular to the transmission axis when light having a wavelength of 590 nm is incident on the polarizing membrane.